EP1025425A1

EP1025425A1 - Spectrophotometer system

Info

Publication number: EP1025425A1
Application number: EP99943781A
Authority: EP
Inventors: Robert J. Hutchison; Jay M. Eastman; Peter A. Ciaccia, Jr.
Original assignee: Lucid Inc
Current assignee: CV US Inc
Priority date: 1998-08-20
Filing date: 1999-08-19
Publication date: 2000-08-09
Also published as: CA2329196A1; WO2000014496A1; EP1025425A4; AU5681299A

Abstract

A spectrophotometer system adapted to be inserted into the side of a compact computer or other computerized devices, as an accessory card which may interface with the computer in accordance with the standards of the Personal Computer Memory Card International Association (PCMCIA) is provided. On this card and disposed along an edge thereof is a spectrophotometer (24). The spectrophotometer optics (26) are connected to a fiber optic cable (32) at the end of which is a light receiving and transmitting opening exposed to the object under test. The card may carry a lamp (36) which is coupled to the fiber optic from the spectrophotometer so as to illuminate the object under test. The card has all of the electronics necessary for spectral measurements, including a microprocessor.

Description

Spectrophotometer System

Description

This application claims the priority benefit of U.S. Provisional Application No. 60/097,317, filed 20 August 1999.

The present invention relates to spectrophotometer systems which are integrated into a card adapted to be inserted into a miniature computer, such as a laptop computer, which card may be an industry-standard PCMCIA card. PCMCIA is the acronym for Personal Computer Memory Card International Association which has established the protocols and data formats for computer cards. In general, therefore, the invention provides a compact, lightweight spectrophotometer that can be installed in a standard computer connector which may be associated with a miniature computer or a computer terminal; for example, a handheld computer terminal having its own microprocessor keyboard and display. A range finder may also be integrated into the card for controlling the illumination of the object under test and/or the sensitivity of the spectrophotometer in accordance with its distance form that object, as well as measuring the size of the object and/or its environs.

While spectrophotometers have been mounted on printed circuits, see, for example, U.S. Patents 4,758,085; 4,836,675; and 5,684,582, issued July 19, 1985, June 6, 1989 and November 4, 1997 respectively, and printed circuit cards providing PCMCIA interfaces have been designed to fit into slots in the mother board of a personal computer, see, U.S. Patent 5,872,633 issued February 16, 1999 and an article entitled "Spectrometers Edge Their Way Into Process Monitoring" which appeared in R&D Magazine, January, 1998, p. 36), a spectrophotometer system which is integrated into a plug in card and is packaged to provide a form factor which is adapted for use in mimaturized equipment, as a PCMCIA card, has not heretofore been suggested. Scanners, camera, radios, and pagers on plug in cards have also been proposed, see, U.S. Patents 5,043,721, August 27, 1991 ; 5,468,952, November 21, 1995; 5,902,991, May 11, 1999; 5,913,174, June 15, 1999; and 5,197,545, June 29, 1999. However, the card has been dedicated to electronics functions and other devices have been tethered to the card, and/or the card requires additional devices in its host such as light sources and control circuits for operation. See U.S. Patent No. 5,872,633; 4,836,674; and 4,758,085 (mentioned above) and also U.S. Patents 5,475441, December 12, 1995; 5,887,145, March 23, 1999; 5,914,779, June 22, 1999; and 5,920,342, July 6, 1999.

The invention provides a spectrophotometer mounted on and integrated with a miniature printed circuit card of the PCMCIA class and affords spectrophotometry capabilities in miniature computer and computerized devices such as laptop and palmtop computers and handheld terminals which have slots for PCMCIA cards. In addition, other facilities may be provided, such as illumination of objects under test and measurements of the dimensions thereof, thereby further enhancing the utility of the spectrophotometer system.

Therefore the present invention advances the art by providing an improved spectrophotometer system, and especially a spectrophotometer integrated in a PCMCIA card which is adapted to be inserted into a slot for such cards in miniaturized, computerized devices. The card with its integrated spectrophotometer and other component, except for an edge connector may be an enclosed electro-optic module. Also, in accordance with the invention an essentially solid state spectrophotometer, such as the spectrophotometer sold by American Laubscher Corporation of Farmingdale, N.Y. 11735, may be integrated into a PCMCIA card in a form factor (with dimensions) specified for such a card.

The present invention also provides an improved PCMCIA spectrophotometer card having a plurality of measurement capabilities, including spectral measurement of an object, measurement of the dimensions of the object, and of its environs.

Briefly described, the invention provides a PCMCIA card spectrophotometer system having a card with inner and outer edges, and mounting at the inner edge thereof, a connector adapted to mate with a corresponding (female) connector at the bottom of a PCMCIA card receiving slot of the computerized device. At the outer edge of the card there is integrated therewith as a unit any structure, a spectrophotometer having a detector which provides a spectral output signal. The spectral output signal is processed in a computer processor and controller which receives commands from the computerized device and transmits signals derived from the spectral measurements in the spectrophotometer to the computerized device. The card may carry a source of illumination and connectors for a dual fiber optic cable which carries illumination to the object under test and receives the illumination which is spectrally analyzed in the spectrophotometer integrated into the PCMCIA card. A range finder may also be integrated and enclosed with the spectrophotometer and the card in the unitary structure for spectrophotometer and an illumination control in accordance with the range to the object under test or for measurement of the size of the object and/or its environs.

The foregoing and other objects, features and advantages of the invention will become more apparent from a reading of the following description in connection with the accompanying drawings wherein:

FIG. 1 is a plan view of a PCMCIA spectrophotometer card system located in place in a slot in a computerized device;

FIG. 2 is a simplified, schematic plan view of the spectrophotometer section of the PCMCIA spectrophotometer system;

FIG. 3 is a side view of the spectrophotometer section shown in FIG. 2;

FIG. 4 is a diagram of a PCMCIA spectrophotometer system which is adapted to be still further miniaturized than the system shown in FIGS. 1-3 by use as an application specific integrated circuit;

FIG. 5 is a block diagram of the circuit of the application specific integrated circuit of the PCMCIA card spectrophotometer system shown in FIG. 4;

FIG. 6 is a plan view of a PCMCIA dual function spectrophotometer and range finder card; and

FIG. 7 is a block diagram of the circuitry of the card illustrated in FIG. 6.

Referring to FIG. 1, there is shown a slot 10 for PCMCIA cards having an open end 12 and a connector 14, such as a standard PCMCIA card connector, which may be a female connector, at the bottom of the slot. The slot may be in a miniature, computerized device, such as a computer terminal, laptop computer or other device which has PCMCIA card slots.

A PCMCIA card 16 has at the inner edge (not shown) thereof a standard PCMCIA card connector 18. When the card 16 is inserted into the slot 10, the connector 18 engages the connector 14 to provide connections to the computer of the computerized device having the slot 10, as for example to the bus which is connected to the computer and carries operating power and signals.

The integrated spectrophotometer card has the advantage of a unitary construction in which the electro-optic module is completely enclosed as indicated by the dash line 19 with the exception of the electrical connectors 18, optional power connector for power supply 40 and optical interfaces to the spectrophotometer 24. The optical interfaces are preferably fiber-optic connectors 32 and 34. By completely enclosing the electro-optic module, the system is especially suitable for use in which it is swapped in and out of computer 10. The enclosure protects against mechanical and electrical damage when the card is being handled or stored outside of the computer 10. The preferred enclosure is a sheet metal or plastic enclosure which wraps in circumferential manner around the card and its integrated with the connector 18 and the optical interface of spectrophotometer 24. The outside dimensions of this enclosure are with the PCMCIA standards.

At the front edge 20 of the card 16, and preferably projecting out of the open end 12 of the slot 10 is a spectrophotometer 24. The spectrophotometer 24 is preferably integrated into the card 16 to provide a unitary structure package to have a form factor compatible with the dimensional standards for a PCMCIA card. This spectrophotometer is shown generally in FIG. 1 as having an optical section 26 and a detector array 28, which may be enclosed by a cover 27. An optical fiber connector 30 brings light in from an optical fiber 32 (FIG. 1) to the spectrophotometer. This optical fiber may be a dual channel fiber optic cable, wherein a fiber 34 carrying illumination from a lamp 36 mounted on the card 16 is part of the cable. The lamp is operated by a lamp circuit 38 to receive power via the bus and connectors 14 and 18 from the computerized device which receives the card. The lamp 36 and circuit 38 and card are integrated with each other as part of the unitary structure with the spectrophotometer 24. A DC power supply 40 which may be a piece of equipment external of the computerized device may be used to provide power for steady illumination, as an alternative from the power coming from the computerized device itself, and being connected to the lamp circuit 38, as via the bus. In the event that an emissive sample is to be spectrally measured, the lamp 36 need not be energized. If only emissive devices are to be tested, then the lamp 36, the lamp circuit 38 and the dual channel of the fiber 32, 34 need not be used.

Referring to FIGS. 2 and 3, the optical section 26 may receive light from the optical fiber which is directed to a reflecting diffraction grating 42, which has focusing power. Other gratings and lens arrangements can be adapted to provide spectral dispersion and optical focusing. The light may arrive from the fiber 32 at the corner of a light pipe 44 or be transmitted through a partially transmissive mirror 46. The mirror bends the diffracted light and directs it through an aperture 48, preferably to an optical filter 50 which excludes wavelengths out of the range of interest (for example, the range of interest may be the visible range from about 380 to about 750 microns) to a linear array of photodetectors 52, which may be a CCD (charge coupled device) photodetector array or other linear photodetector array. Different spectral components are measured by the photodetectors along the array. Since the light is dispersed by the grating and focused across the linear photodetector array, the spectral components at one end of the wavelength band are received by photodetectors at one end of the array while spectral components at the opposite end of the wavelength band are received at the opposite end of the array. It will therefore be apparent that the spectrophotometer system is integrated with the PCMCIA card as a unitary structure. This integrated construction is a feature of the present invention.

The signals from the detector array 52, are applied to an array processor 54. The processor controls the transmission of the signals corresponding to the spectral components from each photodetector of the array in a specified time sequence. The signals are applied via the processor 54 or directly to a microprocessor 56 which may be associated with memory 58. The memory 58 may contain RAM memory for data storage and non-volatile memory which contains the program for operating the microprocessor. A program for digitizing the signals so as to provide high resolution is discussed in U.S. Patent 5,568,143, issued to R.J. Hutchison, et al. on October 22, 1996 may be implemented in the microprocessor under the control of data from the memory 58.

A communications interface 57 is connected between the microprocessor and lines L, through L_P to the contacts of the connector 18 so as to provide the spectral information to the computerized device having the PCMCIA slot 12. The interface also obtains operating commands from the computerized device and forwards them to the microprocessor to control the gathering of spectral data.

Referring to FIGS. 4 and 5, there is shown another PCMCIA card 60 where the spectrophotometer and all of the other circuit elements shown on the card and described in connection with FIG. 1 above may be incorporated into an opto-electronic ASIC (application specific integrated circuit) 61. This ASIC is mounted on the card 60 and is indicated as spectrophotometer system 62. Fiber optic connectors 64 and 66 connect a dual channel fiber optic cable 68 to an end thereof which may illuminate and receive signals from the object of interest.

The spectrophotometer system 62 may be considered as embedded in the PCMCIA card or ASIC.

The circuitry from the multi-element sensor array 70, which is part of the ASIC and also contains the linear array photodetectors provides timed signals via an array processor 72 to an analog to digital (A/D) converter 74. Signal conditioning in a signal conditioner amplifier or integrator, as in the above-referenced Hutchison patent, may be provided, if desired. The spectral signal to the A/D converter may be successive signals which correspond to successive wavelength increments or components. These signals are converted in the A/D converter 74 and applied to the microprocessor controller 78. The controller also operates the lamp driver circuit 80, either continuously or upon command, to drive the illuminating lamp 82. The microprocessor controller is interfaced with the computerized device utilizing the PCMCIA spectrophotometer by a communications interface circuit 84. All of the circuits 70 through 84 are contained in the ASIC.

Referring to FIGS. 6 and 7, there is shown another PCMCIA card 90 similar to the card 16. This card also includes a spectrophotometer system ASIC 92, incorporating the detector array, lamp driver, processing electronics and range finder electronics. Fiber optic connectors 94 and 96 provides for transmission of the illumination and spectral signals from and into a fiber optic cable 98 as discussed above.

The spectrophotometer card 90 also has a range finder section 100 with transmitting and receiving ultrasonic transducers 102 and 104. These transducers receive a drive signal, for example generally a pulse train 106, from a driver 108 which is turned on and off by a dedicated controller or the microprocessor controller 110. This microprocessor controller is similar to the controller 98 but provides signals for turning on the transducer driver 108 and receiving range signals from a phase discriminator 112. The phase discriminator measures the time difference in terms of the phase relationship of the transmitted or incident pulse train 106 and a reflected pulse train 114, is corresponding to a signal from the input transducer 104. Amplifier 116 increases the amplitude of the reflected signal to an appropriate level for input to the phase discriminator. The microprocessor controller translates the time difference signal into a range signal which is displayed or recorded, and may provide information as to the dimensions of the specimen or object which is being sampled for its spectral constituents, and the dimensions of the environs. The dimensions of the object under test may be obtained and, in the event that the spectrophotometer is used in the decoration of a room with wall covering or paint of desired colors, the size of the room and even the amount of paint can be computed by programs in the microprocessor 56 or its memory 57, or in the host, which may use trigonometric equations; these features being invoked via the host to which the card is connected.

Variations and modifications in the herein described system will undoubtedly suggest themselves to those skilled in the art. Accordingly the foregoing description should be taken as illustrative and not in a limiting some.

Claims

1. A spectrophotometer system which comprises a printed circuit card having opposite ends and adapted to be received in a slot in a computerized device with one end exposed at the open end of the slot, a spectrophotometer on the card integral therewith and accessible at the exposed end thereof.

2. The system according to Claim 1 wherein said card is a PCMCIA card.

3. The system according to Claim 1 further comprising a fiber optic cable connected to the spectrophotometer for transmitting light from an object under test to the spectrophotometer for illuminating the object under test.

4. The system according to Claim 3 further comprising a source of illumination integrated with said card and spectrophotometer as a unitary structure within said form factor, and said cable being a dual cable carrying light from said source for illuminating the object under test.

5. The system according to Claim 1 further comprising a range finder integrated in said card in said unit any structure within said form factor, and disposed adjacent the exposed end of said card, and means for obtaining information from said range finder

6. The system according to Claim 5 wherein said means for obtaining comprises means for controlling one of said spectrometers sensitivity and said illumination of said object in accordance with its range from said card.

7. The system according to Claim 6 wherein said means for obtaining comprises means for measuring the dimension of the size of said object or the environs of said object.

8. The system according to Claim 1 further comprising electronically operated means for processing signals from said spectrophotometer comprising a plurality of components integrated with said card and spectrophotometer and not exceeding said form factor.

9. The system according to Claim 8 wherein said spectrophotometer has an optical section and a detector array said array, and said components being an ASIC integral with said card.

10. The system of claims 1, 2, or 5 wherein the card, spectrophotometer, and range finder are enclosed to provide a unitary, integrated electro-optic module.