WO1994027206A1

WO1994027206A1 - Location-triggered interactive data retrieval system

Info

Publication number: WO1994027206A1
Application number: PCT/US1994/005184
Authority: WO
Inventors: Dewitt E. Harrison; Kevin S. Kirking
Original assignee: Tour Information Systems, Inc.
Priority date: 1993-05-13
Filing date: 1994-05-10
Publication date: 1994-11-24
Also published as: AU6909494A

Abstract

An externally (location) triggered data retrieval system (11) that produces audio information about a historic, geographic, geologic or other site is disclosed. Portable data storage units (15) containing the information to be produced stored in a random access storage device, such as a CD-ROM player, are triggered when the units reach a position in the vicinity of the historic, geographic, geologic or other site. Triggering can be accomplished in various ways. For example, triggering can be accomplished by a portable unit receiving an encoded RF signal emitted by the antenna (23) of a site beacon (13) located near a site, by the output of a global positioning system (GPS) receiver/processor (65) located in the unit (15), by the receipt of an infrared coded signal emitted by the infrared emitter (63) of a beacon located at the site, etc. When triggered, the portable data storage unit (15) searches for and locates information about the site. The located information is broadcast to a nearby audio or audio-visual display device, such as the FM radio (19) of a vehicle in which the unit (15) is located or a television set (71). In addition to the random access storage device, the portable unit includes a small display screen (35) and a keypad (33) for interfacing with a user, as well as suitable electronic circuitry. The keypad allows a user to bypass or repeat information.

Description

LOCATION-TRIGGERED INTERACTIVE DATA RETRIEVAL SYSTEM

Field of the Invention This invention relates to data retrieval systems and, more particularly, to interactive data retrieval systems that store information about historic, geographic, geologic or other sites of interest to tourists and the like.

Background of the Invention Millions of people tour ("tourists") a variety of historic, geographic, geologic and other sites each year in the United States and abroad. In the United States such sites are located in and around national parks, civil war battle fields, historic city districts, etc. Each of these locations usually includes a plurality of sites of historic, geographic, geologic or other significance. The depth of the significance will, of course, vary from tourist to tourist depending upon their education and interest.

In the past, tourists have been provided information about sites of interest in a variety of ways. The most common way is pamphlets and books available from tourist centers describing the various historic, geographic, geologic or other sites of interest at a particular location. A tourist center may also provide a kiosk or display booth where audio-video information about sites of interest at the location is available. Unfortunately, these methods of providing tourist information have a number of disadvantages. Kiosks and display booths require that a tourist remember the audio-video information heard and viewed when the tourist later tours the sites that are the subject of the audio-video information. Further, other tourists talking and moving about kiosks and display booths interfere with the ability of tourists observing or listening to the audio-video information to digest the information being presented. Books, pamphlets and other sources of written information require that a tourist read the information contained in such sources either before or, more often, while viewing the sites that are described in the information. Since tourists are usually under time constraints, either written information is not adequately digested or site viewing time is lost while the information is being read.

In order to overcome the foregoing disadvantages, portable information retrieval devices that allow a mobile user to access information about a particular historic, geographic, geologic or other site have been developed. Existing devices include portable magnetic tape players and portable radio receivers. Portable magnetic tape players enable a listener to hear information about a plurality of sites in a sequential fashion. Portable radio receivers permit a listener to monitor a localized information broadcast about historic, geographic, geologic or other sites. Unfortunately, both portable magnetic tape players and portable radio receivers have a number of disadvantages. Portable magnetic tape players require a tourist ("user") to manually control playback in order to synchronize the timing of information retrieval cycles to the time of arrival at the location of a site to which the played back information relates. This requires the ability to read signs or to interpret other visual cues and to navigate a path between sites in an order that corresponds to the sequential ordering of the taped information segments. While portable radio receivers do not have these disadvantages, they have other disadvantages. The user of a portable radio receiver is especially constrained since he has no control over the timing of the information being received. More specifically, when a user is in the proximity of a particular site, the portable radio receiver begins to receive information. Depending upon where the radio "program" is in its cycle, the user may first hear the beginning of the program, the middle of the program, the end of the program or anywhere in between. In order to hear the entire program related to the site, the user must wait until the program ends and, then, begins again. Further, a user has no ability to bypass portions of the program that are not of interest. A serious shortcoming of all of the presently existing ways of providing tourist information is that the information available to a tourist or other users is very limited in quality, form and flexibility of access. This is partially due to the information storage capacity of each technology and partially due to the means of access. A tape player, for example, does not have sufficient data capacity to store and reproduce high quality pictorial information or to mix information data types. Further, the sequential nature of data storage and retrieval combined with the problematic ability to easily locate a desired information segment and the long-time delays associated with tape transport operations between nonsequential segments make it difficult for a tourist to selectively access only the information of interest.

The present invention is directed to providing a location-triggered interactive data retrieval system that overcomes the disadvantages described above.

Summary of the Invention In accordance with this invention, an externally (location) triggered data retrieval system that produces audio or audio-video information about a historic, geographic, geologic or other sites is disclosed. A portable data storage unit, containing the information to be produced stored in a random access storage device, such as a CD-ROM player, is externally triggered by an encoded signal when the unit is in the vicinity of the historic, geographic, geologic or other site. Based on the nature of the encoded signal, i.e., the code contained in the encoded signal, the triggered portable data storage unit searches for and locates information about the site. The located information is broadcast to a nearby audio or audio-video display device, such as the radio of an automobile or a television set. In addition to the random access storage device, the portable unit includes a small display and a keypad for interacting with a user, as well as suitable electronic circuitry for controlling the operation of the unit. The small display also can be used to provide visual information to a user.

In accordance with further aspects of this invention, the portable data storage unit is triggered by an encoded radio frequency (RF) signal emitted by the antenna of a beacon located near each historic, geographic, geologic or other site. Each code is site related such that the receipt of an encoded RF signal causes the portable data storage unit to access stored information related to the site. The stored information modulates an FM or other carrier signal suitable for causing the audio or audio-video device to produce an output when the device is suitably tuned.

In accordance with alternative aspects of this invention, the portable data storage unit is triggered by the output of a global positioning system (GPS) receiver/processor or the encoded signal produced by an infrared optical transmitter. In accordance with other aspects of this invention, the keypad allows the user (i.e., a tourist or student) to control information produced by the portable data storage unit and, thus, bypass information that is not of interest to the user, have information repeated or access additional supplemental information. As will be readily appreciated from the foregoing description, the invention provides a location-triggered interactive data retrieval system. Because the portable data storage unit stores data in a randomly accessible storage medium, such as a CD-ROM, information access time is significantly reduced when compared to serial data storage mediums, such as a magnetic tape player. Further, because each portable data storage unit is separately triggered, the segment of stored information related to a particular site begins at the beginning of the segment when the site is reached. Further, if desired, a user can bypass undesired information, or have information repeated. Because a portable data storage unit is utilized, a user does not have to remember information about sites originally received at a central information point, such as a tourist station. Further, because information is generated in audio form, tourists can view a site while receiving information about the site. The use of a high capacity storage medium such as a CD-ROM allows large amounts of site information to be stored and reproduced. Thus, the present invention overcomes many of the disadvantages of prior methods and techniques used to provide historic, geographic, geologic and other site information to tourists and the like. Brief Description of the Drawings

The foregoing and other advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment of the invention, when taken in conjunction with the accompanying drawings, wherein: FIGURE 1 is a pictorial diagram of a location-triggered interactive data retrieval system formed in accordance with the invention;

FIGURE 2 is a pictorial diagram of the portable data storage unit included in the location-triggered interactive data retrieval system illustrated in FIGURE 1 ;

FIGURE 3 is a partially pictorial and partially block diagram showing additional details of portable data storage unit illustrated in FIGURE 2;

FIGURE 4 is a block diagram of an RF transmitter suitable for use in the location-triggered interactive data retrieval system illustrated in FIGURE 1;

FIGURE 5 is a timing diagram illustrating the content of a serial data frame produced by the RF transmitter illustrated in FIGURE 4; FIGURE 6 is a timing diagram illustrating a single character of the serial data frame illustrated in FIGURE 5;

FIGURES 7A and 7B comprise a flow diagram illustrating the operation of the RF transmitter illustrated in FIGURE 4;

FIGURE 8 is a pictorial diagram illustrating an application of a location- triggered interactive data retrieval system of the type illustrated in FIGURE 1; FIGURE 9 is a timing diagram illustrating the time delay between the production of encoded signals by an RF transmitter of the type shown in FIGURE 4 for the application shown in FIGURE 8;

FIGURE 10 is a pictorial diagram illustrating the radio module portion of the portable data storage unit illustrated in FIGURES 1-3;

FIGURE 11 is a block diagram illustrating the RF receiver portion of the radio module illustrated in FIGURE 10;

FIGURES 12A-12D comprise a flow diagram illustrating the operation of the RF receiver illustrated in FIGURE 11; FIGURES 13A-13F comprise a flow diagram illustrating the operation of the data retrieval and user interaction portions of the portable data storage unit illustrated in FIGURES 1-3.

Description of the Preferred Embodiment

As will be better understood from the following description of the presently preferred embodiment of the invention, a location-triggered interactive data retrieval system formed in accordance with the invention includes three subsystems—an external trigger subsystem; a portable high capacity random access data storage unit; and an audio (or audio-video) output devise. In this regard, the external trigger subsystem of the location-triggered interactive data retrieval system 11 illustrated in FIGURE 1 comprises a plurality of site beacons 13, only one of which is shown.

FIGURE 1 also includes: a portable data storage unit 15, in the form of a portable

CD-ROM player modified in the manner described below; and an audio output device 17 in the form of a vehicle FM radio 19 and the vehicle antenna 21 associated with the radio. The site beacon 13 includes an RF transmitter (illustrated in FIGURE 4 and described below) and an RF antenna 23. The RF antenna 23 emits coded signals 25 that are received by the antenna of the RF receiver of a radio module 27 (illustrated in FIGURES 10 and 11 and described below) that forms a portion of the portable data storage unit 15.

The portable data storage unit 15 also includes: a CD-ROM drive 29; a main circuit board 31; a keypad 33; and a display screen 35, all housed in a case 37. The main circuit board 31 includes the electronic circuits that control the operation of the CD-ROM drive 29 and the display screen 35. The main circuit board also interfaces with the radio module 27 and the keypad 33 (through an adapter board if required). In addition to an RF receiver suitable for receiving the coded signals produced by the site beacon 13, the radio module 27 also includes an FM transmitter for transmitting the FM signals that are received by the vehicle antenna 21 and reproduced in human audible form by the vehicle FM radio 19 in the manner hereinafter described.

As will be better understood from the following description when the portable unit 15 is brought into the vicinity of the site beacon 13, the portable data storage unit is triggered by the coded RF signal 25 emitted by the antenna 23 of the site beacon. The coding causes the portable data storage unit 15 to enable the CD-ROM drive 29 and locate information stored on a CD-ROM disc in the drive related to the site associated with the site beacon 13. The stored information is reproduced as an FM signal that is picked up by the FM radio antenna 21 and emitted by the vehicle FM radio 19 in audible form, provided the vehicle FM radio is tuned to the correct FM frequency. Menu instructions or other text associated with the site information is reproduced on the display screen. The keypad allows a user to: ..by¬ pass undesired information; cause information to be repeated; access additional supplemental information; or access site information when outside of the trigger region of the site's beacon.

FIGURE 2 illustrates a few more details of the portable data storage unit 15 illustrated in FIGURE 1. More specifically, FIGURE 2 also illustrates that the CD-ROM drive 29 houses a CD-ROM disk 41 and that the radio module 27 includes: a radio subassembly 43; a wiring harness 45 for connecting the radio subassembly to the main circuit board 31; and an internal antenna subassembly 47 connected to the radio subassembly 43. The radio and internal antenna subassemblies are hereinafter illustrated and described in more detail.

FIGURE 3 is a functional block diagram illustrating other details of the location-triggered interactive data retrieval system illustrated in FIGURE 1. More specifically, FIGURE 3 illustrates that the beacon 13 includes a location identification encoder 51 and an RF transmitter 53 in addition to the RF antenna 23. The location identification encoder produces a coded signal that modulates the carrier signal generated by the RF transmitter 53 and emitted by the antenna 23. The coded signal is received by an RF antenna 52, included in the antenna subassembly 47 housed in the portable data storage unit 15, and applied to an RF receiver 54. The received coded RF signal is decoded by a decoder/controller 55, and the decoded signal is supplied to the input processor 67 of the portable data storage unit 15. The RF receiver 54 and the decoder/controller 55 are illustrated in more detail in FIGURE 1 1 and described below. FIGURE 3 also illustrates alternative mechanisms for triggering the portable data storage unit 15. The alternative mechanisms are illustrated in dashed lines. More specifically, FIGURE 3 illustrates that a portable global positioning system (GPS) receiver/processor 55 could be used to produce a signal containing a location code when the GPS receiver/processor 13 is in the vicinity of a site, similar to the manner in which "way points" are used to trigger course changes when a GPS is coupled to a boat autopilot. The location code is received by a suitable receiver 57 and decoded by the decoder/controller 55. The decoder/controller 55 supplies a decoded signal similar to the decoded signal produced by decoding the coded signal produced by the RF transmitters 53 of the site beacons in the manner heretofore and hereinafter described. A further alternative trigger mechanism shown in FIGURE 3 uses infrared energy as the transmission medium. An infrared optical transmitter 59 connected to receive encoded signals produced by the location identification encoder 51 produces a coded signal that modulates the infrared optical energy produced by a light-emitting diode (LED 61). The LED signals are received by a photodiode 63 mounted in the portable data retrieval unit 15. The output of the photodiode is amplified by a receiver 65 and the output of the receiver is decoded by the decoder/controller 55. The decoded signals are again similar to those produced by decoding the coded RF signals produced by the RF transmitter 53.

Regardless of how triggering is accomplished and/or how decoding is accomplished, the decoded signals form control signals that control the operation of the portable data storage unit in the manner hereinafter described. That is, the control signals control the operation of a program that controls the operation of the input processor 67 in the manner hereinafter described. As also shown in FIGURE 3, the keypad also produces control signals, denoted mode commands, that control the operation of the program that controls the input processor 67. The input processor 67 and the decoder/controller 55, along with other electronic components, are mounted on the main circuit board 31 or, if desired, another board if included in the portable data retrieval unit 15. As will be widely appreciated by those skilled in the art and others, the input processor, the decoder/controller and other elements shown herein in functional block form are actually created from various combinations of integrated circuits and discrete components mounted on circuit boards.

The nature, mounting, positioning, etc., of the electronic system for controlling the CD-ROM drive, as well as the CD-ROM drive are not described in detail here because these items per se do not form part of the present invention. CD-ROM drives and CD-ROM drive control systems suitable for use in portable data retrieval units of the type contemplated by this invention are well known and commercially available. One portable CD-ROM player ideally suited for use in the present invention is the Data Diskman produced by Sony Corporation.

FIGURE 3 also illustrates that the audio output, in addition to being transmitted to a commercial broadcast FM radio receiver 19 via an FM transmitter 66 and an FM antenna 68 could be produced in headphones 69. FIGURE 3 also illustrates that, as an alternative to an FM audio signal, the portable data retrieval unit could produce an audio-video signal suitable for receipt by a commercial broadcast television receiver 71.

FIGURE 4 is a block diagram illustrating a site beacon 13 formed in accordance with the invention suitable for use in the location-triggered interactive data retrieval system illustrated in FIGURE 1. More specifically, FIGURE 4 illustrates more details of the stationary location identification encoder 51 and the RF transmitter 53 illustrated in FIGURE 3. As shown in FIGURE 4, the stationary location identification encoder 51 includes: a housekeeping data buffer 81; a location data buffer 83; a remote encoder/controller 85; and a DC-DC converter and supervisory circuit 87. The housekeeping buffer stores maintenance data, such as battery condition, last date of service, presence of moisture as well as anything else useful to the servicing and maintaining of the site beacons. The information is accessible by service personnel equipped with portable units (not shown) modified to save and display the stored data.

The remote encoder/controller includes a read only memory (ROM) 89 for storing the program that controls the operation of the remote encoder/controller, preferably, in the manner illustrated in FIGURES 7A and 7B and described below. The remote encoder/controller also includes a transitory memory, such as a random access memory (RAM) 91 that stores system variables. The remote encoder/controller also includes two timers 93 and 95 designated TIMER 1 and TIMER 2. Further, the remote encoder/controller includes: a serial data output port designated D_out; four digital eight-bit parallel input/output ports designated PI, P2, P3, and P4; a DC power terminal designated V_cc, a reset terminal designated RESET and a ground terminal designated GND. The housekeeping data buffer 81 includes two eight-bit parallel three-state output ports, one coupled to each of the PI and P2 ports of the remote encoder/controller 85; and an enable (EN) terminal coupled to the P4₀ terminal of the P4 port of the remote encoder/controller 85. The location data buffer 83 includes three eight -bit parallel three-state output ports, one coupled to each of the eight terminals of the PI, P2, and P3 ports of the remote encoder/controller; and an enable (EN) terminal coupled to the P4_j port of the remote encoder/controller 85. Each buffer supplies data to the encoder/controller 85 when enabled in a multiplex fashion.

The DC-DC converter and supervisory circuit 87 receives power from one or more batteries 97a, 97b . . . ; and applies suitable voltage DC power across the V_cc and GND terminals of the remote encoder/controller 85. The V_cc or DC power output of the DC-DC converter and supervisory circuit 87 is also connected to the DC power input of the RF transmitter 53. The DC-DC converter and supervisory circuit also supplies a power up input signal to a power up RESET terminal of the remote encoder/controller 85. Further, the DC-DC converter and supervisory circuit 87 supplies a low battery (LB) signal to the P4₃ terminal of the P4 port of the remote encoder/controller 85. Finally, the DC-DC and supervisory circuit includes a watch dog timer whose reset (WD) input is connected to the P4₂ terminal of the P4 port of the remote encoder/controller.

The D_out terminal of the remote encoder/controller is connected to the signal input of the RF transmitter 53. The P4 terminal of the P4 port of the remote encoder/controller is connected to the transmit enable (TX EN) input of the RF transmitter 53.

As shown in FIGURE 5, the frame length of the serial digital data produced at the D_out terminal of the remote encoder/controller is eight ASCII characters long. The first two character positions are sync character positions, designated SYNC 1 and SYNC 2. The second three character positions are location data character positions, designated LOC 1, LOC 2, and LOC 3. The sixth and seventh character positions are housekeeping data character positions designated HK DATA 1 and HK DATA 2; and the final character position is a check sum character position, designated CHECK CHR. As shown in FIGURE 6, each character position is eight bits long. Thus, each character is an eight-bit ASCII character. Any convenient, suitably fast, character bit transmission rate may be used depending on the requirements of a specific application.

FIGURES 7A and 7B form a flow diagram illustrating the program that controls the operation of the remote encoder/controller 85. Upon startup, the remote encoder/controller is reset 201. An early step in the reset subroutine (not shown) is to set a timer, which is regularly tested 203 to determine if a reset time-out period has elapsed. After the reset time-out period has elapsed, the input/output ports PI, P2, P3, and P4 of the remote encoder/controller 85 are initialized 205. Next, the watch dog timer included in the DC-DC converter and supervisory circuit 87 is reset 207 by producing a pulse at the P4₂ terminal of the P4 port of the remote encoder/controller 85. Then, TIMER 1 and TIMER 2 are both loaded with a watch dog reset delay value 209. Thereafter, a test 211 is made to determine if the watch dog timer time-out period has elapsed.

If the watch dog time-out period has elapsed, the controller is reset. If the watch dog timer time-out period has not elapsed, a test 213 is made to determine if the watch dog reset delay period value stored in TIMER 1 has elapsed. If the watch dog reset delay period stored in TIMER 1 has elapsed, the watch dog timer is again reset by producing a pulse at the P4₂ terminal of the P4 port of the remote encoder/controller 85. If the watch dog reset delay period stored in TIMER 1 has not elapsed, a test 215 is made to determine if the battery charge is low. If the battery charge is low, as determined by checking the status of the LB output of the DC-DC converter and supervisory circuit, a low battery status bit is set 217 in the housekeeping data buffer 81. If the battery power is not low, the low battery status bit in the housekeeping data is cleared 219. Next, a test 221 is made to determine if the transmit delay time-out period stored in TIMER 2 has elapsed. If the transmit delay time-out period stored in TIMER 2 has not elapsed, the program cycles to the watch dog time-out period elapsed test 211. If the transmit delay time stored in TIMER 2 has elapsed, the current values of data at ports PI, P2 and P3 is read 223 and the data is formatted 225 into a serial data frame. Reading the data is accomplished by sequentially applying enable signals to the enable inputs of the housekeeping, and location data buffers 81 and 83 and reading the data outputs of these buffers. The buffer data is combined with predetermined sync data to create a serial data from frame of the type shown in FIGURE 5. The check sum character data is, of course, determined by the nature of the sync, location and housekeeping data. Thereafter, a transmit enable (TX EN) pulse is applied 227 to the P4₄ terminal of the P4 port of the remote encoder/controller 85. During the TX EN pulse period, the formatted data is output 229 via the digital data output port (D_out). Next, a new random delay offset value is produced 231. The delayed offset value is added 233 to a base transmit delay value and the result loaded 235 into TIMER 2. Thereafter, the program cycles to the watch dog time-out period elapsed 235 test 211 described above.

In order to save battery power, the data frame duty cycle of the FM transmitter, which is controlled by the value stored in TIMER 2, is low. As illustrated in FIGURE 8, the duty cycle or repetition rate, R, of the FM transmitter, is primarily determined by the period of time that a vehicle, within which a portable data storage unit 15 is located, is within a zone where reception of the FM transmitter (beacon) signal is reliable. This period of time is determined by the length of the vehicle path in the reliable reception zone and the maximum speed of the vehicle through the zone. More specifically, the minimum repetition rate, R_mj_n, in cycles per second (Hz) is equal to the maximum speed of the vehicle, S_max, in meters per second divided by the vehicle path distance, D, in meters. This repetition rate ensures that a vehicle traveling along the designated path will receive at least one beacon signal cycle at any speed equal to or less than S_max, since the transmission delay time, T^, is the inverse of repetition rate, T^ = 1/R-min* The transmission time delay, Tj, is, of course, the value stored in TIMER 2, i.e., the value to which TIMER 2JS initially set. In addition to conserving battery power, a low duty cycle allows multiple beacons to trigger a portable data storage unit. In order to prevent a time conflict between two or more beacons, dither or uncertainty is added to the .off interval by using a random delay offset value to control the exact value initially stored in TIMER 2. As shown in FIGURE 9, T_j varies between a minimum value, (T_(j)_mjn, and a maximum value, (T<ι)_max. The variability in delay time assures that the number of beacon transmission collisions will be minimal and brief. The random delay offset value is added at step 231 in the program. TIMER 1, in essence, prevents the watch dog timer from resetting the system unless a system failure occurs that prevents TIMER 1 from being reset. In this instance, the watch dog timer resets the entire system.

FIGURE 10 illustrates that the radio or module 27 includes an FM transmitter section 101 and an RF receiver section 103. The FM transmitter section 101 includes the FM antenna 68 and the RF receiver section includes the RF antenna 52.

As illustrated in FIGURE 11, in addition to the RF antenna 52, the RF receiver section 103 includes the RF receiver 54 and the decoder/controller 55. The RF receiver 54 includes a signal input that is coupled to the RF antenna 52. The RF receiver 54 also includes a control terminal that receives a serial channel select data signal produced by the decoder/controller 55 and a clock terminal that receives a channel select data clock signal also produced by the decoder/controller 55. The serial channel select data and the channel select data clock signals control the initialization and tuning of the RF receiver to a particular frequency, which can be changed "on the fly" by the decoder/controller 55, if required.

The decoder/controller 55 includes a read-only memory (ROM) that stores the progπ. : that controls the operation of the decoder/controller 55 and a random access memory (RAM) that includes buffers and other memory sections that store transitory data. The decoder/controller also includes a timer 117. In addition to producing the channel select data control output (CS_0Ut) and the channel select data clock signal (CS_cik) the decoder/controller 55 also includes a data input terminal (D,_n) connected to the output of the RF receiver 107 and a data output terminal (D_out) that outputs the LOCATION DATA analyzed by the input processor 67 in the manner illustrated in FIGURE 13 and described below. The decoder/controller also produces two additional output signals one designated READY TO SEND and the other designated CLOCK. The state of the READY TO SEND signal advises the input processor 67 when the decoder/controller is ready to send location data to the input processor for processing. The CLOCK signal is used to synchronize the receipt of the received data. The decoder/controller also receives a signal from the input processor designated READY TO RECEIVE. The state of the READY TO RECEIVE signal advises the decoder/controller when the input processor is ready to receive data.

" FIGURES 12A-12D form a flow diagram illustrating in the operation of the decoder/controller 55 illustrated in FIGURE 11. When the decoder/controller is first powered up, it is reset 301. Thereafter, a test 303 is made to determine if a reset time-out period established by the timer 117 has elapsed. If the time-out period has not elapsed, the controller remains in a reset controller loop until the time-out period has elapsed. After the time-out period has elapsed, all of the serial data ports (D_jn, D_out, and CS_0Ut) are initialized 305. Next, the state of a FRAME RECEIVED status bit is cleared 307. Then a READY TO SEND status bit is cleared 309. Next, the size of a log buffer is set to zero 311. As will be better understood from the following description, the log buffer stores location information and prevents location identification signals from causing duplicate data transfers from the CD-ROM storage device to the output device, i.e., the FM radio. After the log buffer size is set to zero, a SYNC 1 RECEIVED status bit is cleared 313. Then, a FRAME SYNC status bit is cleared 315. At this point, the decoder/controller is ready to receive data. Thus, the next step is to poll 317 the serial input character buffer that receives data from the RF receiver to determine if a valid character has been received. If a valid character has not been received, the program cycles to a test 321 to determine if a READY TO SEND status bit is set (FIGURE 12D). If the READY TO SEND status bit is not set, the serial input character buffer is again polled.

When a valid character is received, a test 323 (FIGURE 12B) is made to determine if the FRAME SYNC status bit is set. If the FRAME SYNC status bit is not set, a test 325 is made to determine if the binary value of the received character is equal to the SYNC 1 binary value, i.e., the binary value of the first synchronization character. See FIGURE 5. If the values are equal, the SYNC 1 RECEIVED status bit is set 327. Thereafter, the serial input character buffer is cleared 329. If the binary value of the received character is not equal to the SYNC 1 binary value, a test 331 is made to determine if the binary value of the received character is equal to the SYNC 2 binary value, i.e., the binary value of the second synchronization bit. If the values are equal, a test 333 is made to determine if the SYNC 1 RECEIVED status bit is set. If the SYNC 1 RECEIVED status bit is not set, the serial input character buffer is cleared 329. If the SYNC 1 RECEIVED status bit is set, the FRAME SYNC status bit is set 335. Then, a frame receipt time-out period delay value is loaded 337 into the timer 117. Next, a frame check sum and frame buffer pointer is cleared 339. Thereafter the SYNC 1 RECEIVED status bit is cleared 341. Then the serial input character buffer is cleared 329. If the binary value of the received character is not equal to the SYNC 2 binary value 331, the SYNC 1 RECEIVED status bit is cleared 341. Then the serial input character buffer is cleared 329. As will be appreciated from the foregoing description, SYNC 1 and SYNC 2 characters must be received in the appropriate order in order for the FRAME SYNC status bit 335 to be set. Not only must the sync characters be received, as noted, they must be received in the appropriate order. A SYNC 2 character will not be recognized unless a SYNC 1 character has been recognized since the SYNC 1 RECEIVED bit must be set before the receipt of a SYNC 2 character causes the FRAME STATUS bit to be set. Until the FRAME SYNC status bit is set 323, received character data is not analyzed to determine if location (LOC) or housekeeping (HK DATA) data has been received.

After the SYNC characters have been received and the FRAME SYNC status bit is set 323, a test 343 is made to determine if the frame receipt time-out period has elapsed. If the frame receipt time-out period has elapsed, the FRAME SYNC status bit is cleared 345. Then, the input serial character buffer is cleared 329.

If the frame receipt time-out period has not elapsed 343, the value of the received character is added 347 to the frame check sum value. Addition overflows, or carries, are not saved. Thereafter, the character is stored 349 at the frame buffer pointer location. Then the frame buffer pointer is incremented 351.

Next, a test 353 is made to determine if the frame buffer pointer is equal to or greater than the buffer size. If the frame buffer pointer is not equal to or greater than the buffer size, the serial input character buffer is cleared 329. If the frame buffer pointer is equal to or greater than the buffer size, a test 355 is made to determine if the current character is equal to the value of the check sum. If the current character is equal to the value of the check sum, valid data has been received. If the current character is not equal to the value of the check sum, the data received is invalid. If the data received is invalid, the FRAME SYNC status bit is cleared 345. Thereafter, the serial input character buffer is cleared 329. If valid data has been received, i.e., the current character is equal to the value of the check sum, the FRAME RECEIVED status bit is set 357. Thereafter, the frame buffer contents is transferred 359 to the output buffer. Then, the FRAME SYNC status bit is cleared 345, followed by the serial input character buffer being cleared 329.

At this point it will be appreciated that the program has evaluated all characters occurring after the SYNC 1 and SYNC 2 characters. As the characters are received, they are added to a frame buffer. At the same time, the binary values of the characters are added together. When the frame buffer becomes full, a test is made to determine if the current character is equal to the check sum value. If not equal to the check sum value, the received data is considered invalid and, thus, not transferred to the output buffer. If the current character is equal to the value of the check sum, the data is transferred from the frame buffer to the output buffer and the FRAME SYNC status bit is cleared, setting up the system to receive and evaluate another character frame.

As shown in FIGURE 12C, after the serial input character buffer is cleared, a test 361 is made to determine if the FRAME RECEIVED status bit is set. If the FRAME RECEIVED status bit is not set, the program cycles to the READY TO SEND status bit test 321 (FIGURE 12D).

After the frame received status bit is set in the manner heretofore described, as shown in FIGURE 12C, the log buffer pointer is set 363 to zero. Next, the value of the three characters at the log buffer pointer position and the next two pointer positions are compared 365 to the characters stored at positions LOC 1, LOC 2 and LOC 3 (see FIGURE 5) in the output buffer. Next, a test 367 is made to determine if all three characters match. If the three characters match, three is added 369 to the pointer value. Then a test 371 is made to determine if the new pointer value is equal to or greater than the log buffer size. If the pointer value is not equal to or greater than the log buffer size, the value of the three characters at the log buffer pointer position and the next two positions are compared 365 to the characters stored at positions LOC 1 , LOC 2 and LOC 3 in the output buffer. The program remains in this loop until the log buffer pointer value becomes equal to or greater than the log buffer size 371. When this occurs, the READY TO SEND status bit 373 is set. Thereafter, the FRAME RECEIVED status bit is cleared 375. If, during the foregoing cycle, a three-character match is found, the READY TO SEND status bit is not set. Rather, only the FRAME RECEIVED status bit is cleared.

As shown in FIGURE 12D, after the READY TO SEND status bit test is passed, a test 377 is made to determine if the READY TO RECEIVE input from the host is active, meaning that the input processor 69 is ready to receive data. If the READY TO RECEIVE input from the host is not active, the program cycles to the point where the serial input character buffer is polled 317. If the READY TO RECEIVE input from the host is active, the log buffer size is increased 379 by three bytes, i.e., by three character byte lengths. Thereafter, characters at positions LOC 1, LOC 2 and LOC 3 in the output buffer are appended 381 to the end of the log buffer. Next, the contents of the output buffer are sent 383 to the host via the D_out port. Thereafter, the READY TO SEND status bit is cleared 385, and the program cycles to the point where the input character buffer is polled 317 (FIGURE 12A).

As will be appreciated by those skilled in this art and others from the foregoing description, the log buffer is continuously increased in size and three new location characters (LOC 1, LOC 2 and LOC 3) are added to this buffer each time they are deleted. The log buffer is checked each time a new set of characters is received to determine if the received location characters were previously received. If previously received, the received data is not transferred to the output buffer and, thus, not sent to the host, i.e., the input processor. As a result, the CD-ROM player is prevented from repeating outputs if the same beacon signal is received twice.

FIGURES 3A-13F form a flow diagram illustrating how the input processor 67 controls the operation of the portable data storage unit 15. As will be understood from the following description, the portable data storage unit can be remotely triggered by site beacons or controlled by the keypad 33. As shown in

FIGURES 2 and 3, the keypad in a ten-digit numeric keypad includes keys for the digits 0-9 plus a yes (Y) key, a no (N) key, a forward (») key and a reverse («) key.

As shown in FIGURE 13 A, after startup, an initial graphic is displayed.

Thereafter, a test 403 is made to determine if a time-out period has elapsed. If the time-out period has not elapsed, the initial graphic display continues. After the time¬ out period has elapsed, a site menu is displayed 405. Then a test 407 is made to determine if a site selection has been made by the user entering a suitable numeric code via the keypad. If no site selection has been made, a test 409 is made to^' determine if a time-out period has elapsed. If the time-out period has not elapsed, the site selection test 407 is repeated. After a site selection has been made, or after the time-out period has elapsed, either the selected site or a default site number (numeric code) is stored 41 1. Then, a rental/copyright notice is displayed 413. Thereafter, a test 415 is made to determine if a time-out period has elapsed. If the time-out period has not elapsed, the rental/copyright notice display continues.

After the time-out period has elapsed, a CHAPTER SEARCH status bit is cleared 417 (FIGURE 13B). Next, a chapter search message is displayed. Then, a test 421 is made to determine if the yes (Y) key has been depressed. If the yes key has not been pressed, a test 423 is made to determine it a time-out period has elapsed. If the time-out period has not elapsed, the chapter search message display continues. If the yes key is depressed or after the time-out period has elapsed, a chapter entry message is displayed 425. Next, a test 427 is made to determine if the CHAPTER SEARCH status bit is set. If the CHAPTER SEARCH status bit is not set, a test 429 is made to determine if one of the 0-9 digit keys has been pressed. See FIGURE 13C. If one of the 0-9 status keys has not been pressed, a test 431 is made to determine if the chapter entry buffer is full. If the chapter entry buffer is not full, the digit is appended 433 to the end of the chapter number stored in the chapter entry buffer. If the chapter entry buffer is full or after the digit has been appended, a test 435 is made to determine if the yes (Y) key has been pressed. If the yes key has been pressed, the chapter search status bit is set 437.

If a 0-9 digit key has not been pressed, a test 439 is made to determine if the chapter entry buffer is empty. If the chapter entry buffer is not empty, the yes (Y) key pressed test 435 occurs. If the yes key has been pressed, as before, the chapter search status bit is set 437.

If the chapter entry buffer is empty, a test 441 is made to determine if the remote entry buffer contains a chapter number. This is a test to determine if a chapter (location) number was forwarded to the input processor by the RF receiver in the manner heretofore described. If the remote entry buffer does contain a chapter number, the chapter number is transferred 443 to the chapter entry buffer. Thereafter, the remote entry buffer is cleared 445. After the remote entry buffer is cleared, the chapter search status bit is set 437. Returning now to FIGURE 13B, if the chapter status bit is set 427, the chapter search status bit is cleared 447. Thereafter, a chapter list is searched 449 for an entry that matches the numbers stored in the chapter entry buffer. After the search has been completed, a test 451 is made to determine if the search of the chapter list ^' was successful. If the search was unsuccessful, a search unsuccessful message is displayed 453. Thereafter, a test 455 is made to determine if a time-out period has elapsed. If the time-out period has not elapsed, the search unsuccessful message display continues. After the time-out period has elapsed, the program cycles to the chapter entry message display 425.

If the chapter list search was successful, as shown in FIGURE 13D. a chapter found message is displayed 457. Thereafter, a test 459 is made to determine if the no (N) key has been pressed. If the no key has been pressed, the chapter entry buffer is cleared 461. If the no key has not been pressed, a test 463 is made to determine if the yes (Y) key has been pressed. If the yes key has not been pressed, a test 465 is made to determine if a time-out period has elapsed. If the time-out period has not elapsed, the chapter found message display continues 457. After the time-out period has elapsed or if the yes key has been pressed, the current program location is set to the start of the found chapter 467. That is, the CD-ROM controller is set to point to the start of the chapter found during the chapter list search 449. Thereafter, an audio status bit is set 469. Then, the graphic associated with current audio segment is displayed 471 on the display screen 35. Returning now to FIGURE 13C, if the yes key was not pressed 435, as shown in FIGURE 13D, a test 473 is determined if either the « key or the » key has been pressed. At this point in the program, either key will function as a delete key. If either the « key or the » key has been pressed, the last digit entered is deleted and the display backspaced one place 475. After this occurs or if neither the « key nor the » key has been pressed, a test 477 is made to determine if the no (N) key has been pressed. If the no key has been pressed, the chapter entry buffer is cleared 461. If the no key has not been pressed, or after the chapter entry buffer is cleared, the program cycles to the point where the chapter entry message display 425 (FIGURE 13B) occurs. As shown in FIGURE 13E, after the command to display the graphic for the current audio segment, a test 479 is made to determine if the no (N) key has been pressed. If the no key has been pressed, the chapter entry buffer is cleared 481 and the program cycles to the chapter entry message display 425 (FIGURE 13B). If the no key has not been pressed, a test 483 is made to determine if the yes (Y) key has been pressed. If the yes key has been pressed, a test 485 is made to determine if the audio status bit is set. If the audio status bit is set, the audio status bit is cleared 487, which causes the audio output from the CD-ROM to halt and the location of the halt to be saved 489. Thereafter, the no key press test 479 is repeated, followed by the^' yes key press test 483. If the yes key has been pressed, the audio status bit test is repeated. If the audio status bit has not been set, the audio status bit is set 491. Thereafter, the audio program is resumed from the saved location point 493. After the program resume command occurs, or if the yes key has been pressed, a test 495 is made to determine if the current audio segment is completed. If the current audio segment is completed, a test 497 is made to determine if there is a following audio segment in this chapter, i.e., in the found chapter. If there is no following audio segment, the chapter entry buffer is cleared 481 and the program cycles to the chapter entry message display 425 (FIGURE 13B).

As shown in FIGURE 13F, if the current audio segment is not completed, a test 499 is made to determine if the » key has been pressed. If the » key has been pressed, a test 501 is made to determine if there is a following audio segment in this chapter, i.e., in the found chapter. If there is a following audio segment, the audio status bit is set 503. Thereafter, the CD-ROM pointer changes to the beginning of the following segment 505. Likewise, returning to FIGURE 13E, if the "is there a following audio segment in this chapter" test 497 was passed, the CD-ROM pointer changes to the beginning of the following segment 505. If the » key has not been pressed or if there is no following audio segment, or after the following audio segment has been started, a test 507 is made to determine if the « key has been pressed. If the « key has been pressed, a test 509 is made to determine if a preceding audio segment in this chapter, i.e., the found chapter, exists. If a preceding audio segment exists, the audio status bit is set 511. Thereafter, the CD-ROM pointer is set to the start of the preceding segment 513. After this occurs, or if the « key has not been pressed or if there is no preceding audio segment, the program cycles to the point where the graphic for the current audio segment is displayed 471 (FIGURE 13D).

As will be readily appreciated from the foregoing description, the invention provides a location-triggered interactive data retrieval system that is ideally suited for use by tourists or others visiting national parks, monuments or other amusement areas that are traveled through by automobile or other vehicle. The invention includes portable data storage units that store audio or audio video data. The portable data storage units are remotely triggered, i.e., triggered by a location beacon or some other suitable device such that information associated with a particular site is generated when a user approaches the site. Preferably, the generated information modulates an FM signal that is received by the antenna of the vehicle and produced in an audible form by an FM receiver tuned to the appropriate frequency. Alternatively, by the use ' of earphones and a portable battery power supply, the generated information could be heard by a pedestrian or tour bus passenger. If desired, visual information can be displayed on a suitable visual display device, such as a commercial broadcast TV, or a smaller screen display that forms part of the portable data storage units. The use of a random access storage medium, such as a CD-ROM, provides both rapid access and large storage capacity. In addition to simply identifying location, the trigger signals could include other information, such as time of day, season of the year, etc., which vary and, thus, be used to determine the selection of the stored data being retrieved.

While a preferred embodiment of the invention has been illustrated and described, it is to be understood that various changes can be made therein without departing from the spirit and scope of the invention. Consequently, it should be understood that within the scope of the appended claims, the invention can be practiced otherwise than as specifically described herein.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A location-triggered interactive data retrieval system for producing information in human understandable form about historic, geographic, geologic or other sites of interest to a user when the user is in the vicinity of such sites, said location-triggered interactive data retrieval system comprising:

(a) at least one portable data storage unit, said portable data storage unit including:

(i) a high-density random access storage device for storing data containing information about historic, geographic, geologic or other sites of interest to a user;

(ii) a receiver for receiving trigger signals containing site codes related to said historic, geographic, geologic or other sites and in response to the receipt of a site code searching said storage device for data containing information about the site related to said received code; and

(iii) a transmitter for receiving data stored in said storage device and transmitting a signal containing information about a historic, geographic, geologic or other site derived from data stored in said storage device located during said search of said storage device in response to the receipt of a site code;

(b) trigger means for producing said trigger signals that contain said site codes for receipt by said receiver when said at least one portable data storage unit is in the vicinity of a historic, geographic, geologic or other site about which data containing information about said historic, geographic, geologic or other site is stored in said storage device; and

(c) output means for receiving said signal containing information about historic, geographic, geologic or other sites transmitted by said transmitter of said at least one portable data storage unit and producing said information in human understandable form.

2. A location-triggered interactive data retrieval system as claimed in Claim 1, wherein said high-density random access storage device is a CD-ROM player.

3. A location-triggered interactive data retrieval system as claimed in Claim 1, wherein said trigger means comprises a plurality of site beacons, one site beacon located in the vicinity of each of the historic, geographic, geologic or other sites about which data containing information about said historic, geographic, geologic or other site is stored in said storage device.

4. A location-triggered interactive data retrieval system as claimed in Claim 3, wherein said high-density random access storage device is a CD-ROM player.

5. A location-triggered interactive data retrieval system as claimed in Claim 3, wherein said trigger signals produced by said site beacons are encoded radio frequency (B.F) signals, and wherein said receiver of said at least one portable data storage unit is adapted to receive said encoded RF signals.

6. A location-triggered interactive data retrieval system as claimed in Claim 5, wherein said high-density random access storage device is a CD-ROM player.

7. A location-triggered interactive data retrieval system as claimed in Claim 3, wherein said trigger signals produced by said site beacons are encoded infrared signals and wherein said receiver of said at least one portable data storage unit is adapted to receive encoded RF signals.

8. A location-triggered interactive data retrieval system as claimed in Claim 7, wherein said high-density random access storage device is a CD-ROM player.

9. A location-triggered interactive data retrieval system as claimed in Claim 1, wherein said trigger means includes a global positioning system (GPS) receiver/processor.

10. A location-triggered interactive data retrieval system as claimed in Claim 9, wherein said high-density random access storage device is a CD-ROM player.

11. A location-triggered interactive data retrieval system as claimed in Claim 1 , wherein said at least one portable data storage unit includes a keypad and a display for allowing a user to interface with said at least one portable data storage unit.

12. A location-triggered interactive data retrieval system as claimed in Claim 11, wherein said high-density random access storage device includes a high- density random access storage medium and an input processor for controlling the operation of said high-density random access storage medium in response to the receipt of signals from said receiver or input commands provided by a user via said keypad.

13. A location-triggered interactive data retrieval system as claimed in Claim 12, wherein said high-density random access storage medium is a CD-ROM.

14. A location-triggered interactive data retrieval system as claimed in Claim 12, wherein said input processor only allows said high-density random access storage medium to output information about a historic, geographic, geologic or other site once in response to the receipt of a particular site code.

15. A location-triggered interactive data retrieval system as claimed in Claim 14, wherein said high-density random access storage medium is a CD-ROM.

16. A location-triggered interactive data retrieval system as claimed in Claim 14, wherein said keypad allows a user to control said input processor such that said input processor produces signals that cause said high-density random access storage medium to produce information for transmission by said transmitter about historic, geographic, geologic or other sites stored in said high-density random access storage medium in response to keypad commands input by said user.

17. A location-triggered interactive data retrieval system as claimed in Claim 16, wherein said high-density random access storage medium is a CD-ROM.

18. A location-triggered interactive data retrieval system as claimed in Claim 16, wherein said trigger signals include synchronization codes and wherein said receiver only recognizes site codes if it receives acceptable synchronization codes prior to the receipt of site codes.

19. A location-triggered interactive data retrieval system as claimed in Claim 11, 12, 14, 16, or 18, wherein said trigger means comprises a plurality of site beacons, one site beacon located in the vicinity of each of the historic, geographic, geologic or other sites about which data containing information about said historic, geographic, geologic or other site is stored in said storage device.

20. A location-triggered interactive data retrieval system as claimed in Claim 19, wherein said high-density random access storage medium is a CD-ROM.

21. A location-triggered interactive data retrieval system as claimed in Claim 19, wherein said trigger signals produced by said site beacons are encoded radio frequency (RF) signals, and wherein said receiver of said at least one portable data storage unit is adapted to receive said encoded RF signals.

22. A location-triggered interactive data retrieval system as claimed in Claim 21, wherein said high-density random access storage medium is a CD-ROM.

23. A location-triggered interactive data retrieval system as claimed in Claim 19, wherein said trigger signals produced by said site beacons are encoded infrared signals and wherein said receiver of said at least one portable data storage unit is adapted to receive encoded RF signals.

24. A location-triggered interactive data retrieval system as claimed in Claim 23, wherein said high-density random access storage medium is a CD-ROM.

25. A location-triggered interactive data retrieval system as claimed in Claim 19, wherein said trigger means includes a global positioning system (GPS) receiver/processor.

26. A location-triggered interactive data retrieval system as claimed in Claim 25, wherein said high-density random access storage medium is a CD-ROM.

27. A location-triggered portable data storage unit for producing information in human understandable form about historic, geographic, geologic or other sites of interest to a user, said location-triggered portable data storage unit comprising: a high-density random access storage device for storing data containing information about historic, geographic, geologic or other sites of interest to a user; a receiver for receiving trigger signals containing site codes related to said historic, geographic, geologic or other sites and in response to the receipt of a site code causing said high-density random access storage device to search for data containing information about the site related to said received site code; and a transmitter for receiving data stored in said storage device and transmitting a signal containing information about a historic, geographic, geologic or other site derived from data stored in said storage device located during said search of said storage device in response to the receipt of a site code.

28. A location-triggered portable data storage unit as claimed in Claim 27, including a keypad and a display for allowing a user to interface with said portable data storage unit.

29. A location-triggered portable data storage unit as claimed in Claim 28, wherein said high-density random access storage device includes a high-density random access storage medium and an input processor for controlling the operation of said high-density random access storage medium in response to the receipt of signals from said receiver or input commands provided by a user via said keypad.

30. A location-triggered portable data storage unit as claimed in Claim 29, wherein said high-density random access storage medium is a CD-ROM.

31. A location-triggered portable data storage unit as claimed in Claim 29, wherein said input processor only allows said high-density random access storage medium to output information about a historic, geographic, geologic or other site once in response to the receipt of a particular site code.

32. A location-triggered portable data storage unit as claimed in Claim 31, wherein said high-density random access storage medium is a CD-ROM.

33. A location-triggered portable data storage unit as claimed in Claim 31, wherein said keypad allows a user to control said input processor such that said input processor produces signals that cause said high-density random access storage medium to produce information for transmission by said transmitter about historic, geographic, geologic or other sites stored in said high-density random access storage medium in response to keypad commands input by said user.

34. A location-triggered portable data storage unit as claimed in Claim 33, wherein said high-density random access storage medium is a CD-ROM.

35. A location-triggered portable data storage unit as claimed in Claim 33, wherein said trigger signals include synchronization codes and wherein said receiver only recognizes site codes if it receives acceptable synchronization codes prior to the receipt of site codes.