WO2007021143A1

WO2007021143A1 - Pan/tilt camera apparatus having auxiliary camera

Info

Publication number: WO2007021143A1
Application number: PCT/KR2006/003233
Authority: WO
Inventors: Bae Hoon Kim
Original assignee: Bae Hoon Kim
Priority date: 2005-08-18
Filing date: 2006-08-17
Publication date: 2007-02-22
Also published as: JP2008529446A; KR100633033B1

Abstract

A pan/tilt camera apparatus having an auxiliary camera is disclosed. The pan/tilt camera apparatus of the present invention includes an auxiliary camera module (100), which scans a large area including an imaging area of the main camera module, and includes two cameras (HOa) and (110b) disposed such that two adjacent image incidence lines of the cameras are parallel to each other. The pan/tilt camera apparatus further includes a camera mounting frame (120), which has first and second surfaces (122a) and (122b) angled at a predetermined angle, and a camera housing (500), which has a receiving space (530) for receiving the main camera module, the auxiliary camera module and the image combining circuit unit therein. An opening for ensuring vision of the main and auxiliary camera modules is formed in the camera housing.

Description

PAN/TILT CAMERA APPARATUS HAVING AUXILIARY

CAMERA

Technical Field

[1] The present invention relates, in general, to pan/tilt camera apparatuses and, more particularly, to a pan/tilt camera apparatus having an auxiliary camera, thus increasing the range of functions thereof. Background Art

[2] As well known to those skilled in the art, pan/tilt cameras are cameras that can conduct panning motion and tilting motion to ensure a wide surveillance range even though they use only a single camera. Such pan/tilt cameras are used in banks, public buildings and individual dwellings to prevent trespassing and are used in kindergartens or the like to allow a supervisor to monitor the condition of children, for example, to help the supervisor rapidly be made aware of children who are in danger.

[3] As such, object images obtained by the pan/tilt camera are sent to a central station, and a supervisor monitors the images. Furthermore, the pan/tilt camera may be manually panned and tilted by the supervisor or automatically, so as to monitor trespassers or dangerous conditions in the area of interest.

[4] However, in the conventional pan/tilt camera, because the imaging range of a main camera is relatively limited, it is difficult to monitor trespassers or surrounding conditions of the desired area at a glance.

[5] Furthermore, of application fields of the pan/tilt camera, in the case of an automatic trespass alarm system which automatically raises an alarm when a trespasser is detected in a surveillance area and pans and tilts the camera corresponding to the movement of the trespasser to pursue and monitor the trespasser, there is another problem. In detail, the automatic trespass alarm system is operated by a method in which a trespass detecting sensor is previously provided in a surveillance area so that, when a trespasser is detected, a camera is moved towards the area where the trespasser is detected and pursues the trespasser, or by a method in which image signals are processed in units of frames and are stored in a separate frame memory, and whether a trespasser exists is determined through checking for change in the screen by comparing a present image to the stored image.

[6] However, in the former case, if several trespassers exist in the surveillance area, because many signals are generated from several sensors, it is difficult to operate the camera using the signals transmitted from the sensors. In the latter case, because the surveillance area is relatively small, there is a problem of reduced effectiveness in the detection of a trespasser.

[7] Therefore, a pan/tilt camera apparatus which has a wider surveillance area is requir ed. Disclosure of Invention

Technical Problem

[8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a pan/tilt camera apparatus having an auxiliary camera which provides a relatively wide surveillance area, so that a main camera can be rapidly pointed at a trespass area, thus efficiently responding to a trespassing action.

[9] Another object of the present invention is to provide a pan/tilt camera apparatus, in which the auxiliary camera module is provided with two or more cameras to expand the view of the camera, so that images can be displayed on a screen without being processed using particular software.

[10] A further object of the present invention is to provide a pan/tilt camera apparatus in which the auxiliary camera can be easily installed in an existing housing in which a main camera is provided, thus making work at a site convenient. Technical Solution

[11] In order to accomplish the above objects, the present invention provides a pan/tilt camera apparatus including: an auxiliary camera module operating along a direction in which a main camera module scans, and scanning a large area, including the imaging area of the main camera module, the auxiliary camera module comprising two cameras disposed such that two adjacent image incidence lines of the cameras are parallel to each other; a camera mounting frame having first and second surfaces angled at a predetermined angle, with through holes formed in the respective first and second surfaces of the camera mounting frame so that lens units of the cameras are disposed in the respective through holes; and a camera housing having a receiving space for receiving the main camera module, the auxiliary camera module and the image combining circuit unit therein, and an opening for ensuring vision of the main and auxiliary camera modules.

[12] Preferably, each of the two camera lens units may have an optical distortion rate of

15% or less.

[13] Furthermore, the auxiliary camera module may be provided on a pan drive shaft and may have at least two cameras disposed such that two adjacent image incidence lines of the cameras are parallel to each other.

[14] As well, the auxiliary camera module may comprise two auxiliary camera modules provided in the pan drive shaft at opposite positions. In this case, each auxiliary camera module includes first and second surfaces which are angled at a predetermined angle. Through holes are formed in the respective first and second surfaces of the camera mounting frame so that lens units of the cameras are disposed in the respective through holes.

[15] Furthermore, the pan/tilt camera apparatus may further include a protective frame which has an opening and is mounted to the camera housing to protect the auxiliary camera module. Advantageous Effects

[16] The pan/tilt camera apparatus according to the present invention overcomes the limits of the conventional pan/tilt camera apparatuses. For example, because the present invention provides a wider surveillance area to a supervisor, a main camera can be rapidly oriented towards a trespass area, thus efficiently responding to a trespassing action.

[17] Furthermore, an auxiliary camera module for expansion of the view of the main camera includes two or more cameras, and images obtained by the cameras can be displayed on a screen without being processed by particular software.

[18] As well, in the pan/tilt camera apparatus of the present invention, the auxiliary camera module may be provided in an existing housing, in which the main camera module is installed. In this case, the housing having the auxiliary camera module therein can be simply connected to the main camera at a site. As such, because no special effort is required to install the housing, work at a site is convenient. Brief Description of the Drawings

[19] FIG. 1 is a schematic view showing a pan/tilt camera apparatus having an auxiliary camera, according to an embodiment of the present invention;

[20] FIG. 2 is a perspective view of an auxiliary camera module provided in the pan/tilt camera apparatus according to the embodiment of the present invention;

[21] FIG. 3 is a plan view of the auxiliary camera module of FIG. 2 provided in the pan/ tilt camera apparatus of the present invention;

[22] FIG. 4 is a perspective view showing a camera housing used in the pan/tilt camera apparatus according to the embodiment of the present invention;

[23] FIG. 5 is a view showing a protective frame, which is mounted to the camera housing of FIG. 4 to protect the auxiliary camera module;

[24] FIG. 6 is a view showing a pan/tilt camera apparatus having an auxiliary camera, according to another embodiment of the present invention;

[25] FIG. 7 is a view showing a pan/tilt camera apparatus having an auxiliary camera, according to another embodiment of the present invention; and

[26] FIG. 8 is a view showing an enlargement of a portion of a pan/tilt drive unit of FIG. 7, in which an auxiliary camera module is installed. Best Mode for Carrying Out the Invention

[27] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[28] FIG. 1 is a schematic view showing a pan/tilt camera apparatus, according to an embodiment of the present invention.

[29] Referring to FIG. 1, the pan/tilt camera apparatus of the present invention includes a pan drive shaft 430, which is supported on a support column 440 and rotates around the same rotating axis as that of the support column 440, and a tilt arm 420, which is tiltably coupled to the pan drive shaft 430. The tilt arm 420 is coupled to the pan drive shaft 430 using a shaft 410.

[30] Furthermore, in the present invention, a camera housing 500, which is mounted to the tilt arm 420, has a camera receiving space therein and an opening at a predetermined position. A main camera module 200 and an auxiliary camera module 100, which scan the surroundings through the opening, are provided in the camera housing 500. As well, another auxiliary camera module 100a, the structure of which is the same as that of the auxiliary camera module 100, is mounted to the pan drive shaft 430. This auxiliary camera module 100a serves to scan the area behind the main camera module 200.

[31] The main camera module 200 may have a structure such that a zoom lens (not shown) is provided in a typical camera lens unit. Furthermore, the main camera module 200 may have the same structure as that of a typical pan/tilt camera apparatus.

[32] The auxiliary camera module 100 serves to increase the field of vision of the main camera module 200. At least some of the scanning area of the auxiliary camera module 100 overlaps the scanning area of the main camera module 200. Furthermore, the auxiliary camera module 100 scans an area that is larger than the scanning area of the main camera module 200. It is preferable that the main camera module 200 and the auxiliary camera module 100 be disposed such that the scanning area of the main camera module 200 is between the scanning areas of the auxiliary camera module 100.

[33] Images obtained by the main camera module 200 and the auxiliary camera module

100 are combined by an image combining circuit unit 300 and are sent to a display. The image combining circuit unit 300 makes it possible to display images, which are obtained by the main camera module 200 and the auxiliary camera module 100, through one display.

[34] The image combining circuit unit 300 may display only the image from the main camera module 200 in a monitor, or may display only the image from the front auxiliary camera module 100 or the image from the rear auxiliary camera module 100a. Alternatively, the image combining circuit unit 300 may display an image (M) from the main camera module 200 and an image (S) from the front auxiliary camera module 100 or the rear auxiliary camera module 100a in one monitor through a PIP (picture in picture) method (see, picture A of FIG. 1). As a further alternative, the image combining circuit unit 300 may display an image (M) from the main camera module 200 and images (S) from the front and rear auxiliary camera modules 100 and 100a through the PIP method (see, picture B of FIG. 1). As a further alternative, the image combining circuit unit 300 may display images from the camera modules through a selection method. For example, the image combining circuit unit 300 may convert an image from the main camera module 200 to images of the front and rear camera modules 100 and 100a (see, picture C of FIG. 1) or may convert it to an image from only the front camera module 100 (see, picture D of FIG. 1).

[35] FIGS. 2 and 3 are views showing the auxiliary camera module of the present invention.

[36] Referring to FIGS. 2 and 3, the auxiliary camera module 100 includes two cameras

110a and 110b. A CCD (charge-coupled device) type or CMOS (complementary metal oxide semiconductor) type camera may be used as each camera 110a, 110b of the auxiliary camera module. Each camera 110a, 110b includes a lens unit 112a, 112b, an imaging device 114a, 114b and a circuit board 116a, 116b. If a wide-angle lens is used as each lens unit 112a, 112b, the lens unit has a maximum view angle of 90°. As such, in the case in which the auxiliary camera module includes the lens unit having the maximum view angle of 90°, the auxiliary camera module of the present invention can scan a panorama image of 180°.

[37] In the present invention, the cameras 110a and 110b constituting the auxiliary camera module 100 are supported by a camera mounting frame 120. In detail, the camera mounting frame 120 includes first and second surfaces 122a and 122b, each of which has one through hole 125 a, 125b. The lens units 112a and 112b of the cameras 110a and 110b respectively protrude outside the camera mounting frame 120 through the through holes 125a and 125b. The angle between the first and second surfaces 122a and 122b of the camera mounting frame 120 is determined depending on the disposition of the cameras, which is determined so as to achieve the intended purpose of the present invention, and will be described later herein.

[38] Furthermore, the camera mounting frame 120 may have fastening members 122, through which the camera mounting frame 120 is fastened to a desired support structure. Each fastening member 122 may have screw holes 124, so that it is reliably fastened to the support structure using a locking means such as bolts.

[39] Furthermore, the cameras 110a and 110b are mounted to the camera mounting frame 120 through a predetermined method. As shown in the drawings, the circuit boards 116a and 116b of the cameras 110a and 110b may be mounted to the first and second surfaces 122a and 122b of the camera mounting frame 120 using locking means, such as washers 118a and 118b and bolts 117a and 117b. In this embodiment, preferably, elastic members, such as O-rings, are used as the washers 118a and 118b. Such elastic members facilitate precise adjustment of the positions of the cameras 110a and 110b at desired angles.

[40] Referring to FIG. 3, each camera 110a, 110b has a predetermined imaging range, that is, a predetermined view angle. In the drawing, the view angle of each camera 110a, 110b is expressed by image incidence lines (see, dashed arrows). Furthermore, if a wide-angle lens is used as the lens unit 112a, 112b of each camera 110a, 110b, the lens unit can have a maximum view angle of 90°.

[41] Each camera 110a, 110b has a lens unit 112, 112b in addition to the imaging device

(imaging sensor) 116a, 116b.

[42] In the auxiliary camera module 100 of the present invention, the two cameras 110a and 110b are disposed such that the distance between the two adjacent imaging incidence lines I and I of the cameras 110a and 110b is constant, that is, the imaging incidence lines I and I are substantially parallel to each other. This arrangement of the cameras 110a and 110b prevents images, obtained by the cameras 110a and 110b, from overlapping. In the present invention, the term "substantially parallel" in reference to the two adjacent imaging incidence lines, has a meaning including the state in which the imaging incidence lines are mathematically perfectly parallel to each other and, in addition, has a meaning including the state in which the imaging incidence lines are not parallel to each other and do not overlap each other. For example, this state includes the case in which the imaging incidence lines are not perfectly parallel to each other but images do not overlap each other at a typical surveillance distance, that is, the case in which the intersection angle between the two imaging incidence lines (the intersection angle between extension lines of the imaging incidence lines) is 5° or less.

[43] In the present invention, the distance between the two imaging incidence lines I and I depends on the sizes of the lens units 112a and 112b. In the present technological level, this distance can be maintained within a range of several millimeters. Therefore, in the arrangement of the auxiliary camera module 100, a portion, other than the vision angle at which the auxiliary camera module 100 can make observations, is negligibly small.

[44] According to the above-mentioned arrangement of the cameras, images obtained by the two cameras 110a and 110b of the auxiliary camera module 100 are prevented from overlapping each other, so that a single panoramic image can easily be obtained merely by combining the two images. Furthermore, the dead spot formed between the view angles of the two cameras 110a and 110b is negligibly small. [45] Moreover, the conventional camera apparatus has a relatively large optical distortion rate. For example, in the case of a 1/3 inch CCD (charge-coupled device) camera, the conventional art has an optical distortion rate of -80% at the maximum image HT (image height : a medium value of a diagonal line of the CCD) of 2.99 mm. In the case of the conventional retrofocus type lens, because there is a relatively large difference between a reciprocal (-0.19) of a focus length of a front lens group (which is disposed ahead of a diaphragm) and a reciprocal (0.17) of a focus length of a rear lens group (which is disposed behind the diaphragm), the optical distortion rate naturally increases.

[46] In such optical distortion, a monitor distortion rate of -26.7% (equivalent to 1/3 of an optical distortion rate) exists. Due to this, distortion, in which an image is bent more strongly from the center to the perimeter of the monitor, occurs. Therefore, it is necessary to compensate for the optical distortion before an image is displayed on a screen.

[47] However, in the present invention, the distortion rate of the optical lens is limited to

15% (including the distortion rate of the monitor of 5%), so that, even if a separate image processing process is not conducted, images obtained by the cameras of the auxiliary camera module can be represented as a single panoramic image.

[48] Furthermore, there are various methods of minimizing optical distortion, so that various methods can be used to obtain a desired distortion rate. These are not directly related to the present invention, therefore further explanation will be omitted. But, for example, distortion of a lens can be reduced by adjusting the power of the front and rear lens groups. As an example, in a retrofocus type lens, if the power of the front lens group is -0.24 and the power of the front lens group is +0.183, the optical distortion rate of the lens can be maintained at approximately -10% on the basis of an image HT of 2.99 mm in a 1/3 inch CCD camera.

[49] The pictures, which are disposed at the right position in FIG. 1, illustratively show the display of images from the main camera module 200, the auxiliary camera module 100 provided in the camera housing 500, and the auxiliary camera module 100a provided on the pan drive shaft to scan the area behind the main camera 200, the images being combined by the image combining circuit unit 300. The image (M) obtained by the main camera module 200 is displayed at an upper position on a screen, and the image (S) obtained by the auxiliary camera module 100 is displayed at a lower position on the screen. As shown in the pictures, it is appreciated that the image (M) of the main camera module 200 shows a portion of the image (S) of the auxiliary camera module 100.

[50] As described above with reference to FIGS. 2 and 3, the pan/tilt camera apparatus of the present invention can observe an area wider than that of a conventional pan/tilt camera because it includes the auxiliary camera module 100. Therefore, the present invention can be conveniently used in the surveillance and pursuit of trespassers. Furthermore, because the present invention provides wide images to a supervisor, it is easy to adjust the camera in a desired direction through panning/tilting operation of the main camera module 200.

[51] FIG. 4 is a perspective view showing an example of the camera housing 500 of the pan/tilt camera apparatus according to the embodiment of the present invention.

[52] Referring to FIG. 4, the camera housing 500 has therein a camera receiving space

530 for receiving the cameras. An opening 512, which communicates with the camera receiving space 530 and ensures the vision angles of the cameras installed in the camera housing 500, is provided at a predetermined position in the camera housing 500. Furthermore, the auxiliary camera module 100, described above with reference to FIGS. 2 and 3, is provided at a predetermined position in the camera receiving space 530. The main camera module 200 is disposed above the auxiliary camera module 100 in the camera housing 500. As described above with reference to FIGS. 2 and 3, the auxiliary camera module 100 is fastened to a housing body 510 of the camera housing 500 through the fastening members 122. The camera housing 500 includes a protective cover 520, which protects the housing body 510 and the auxiliary camera module 100 provided in the housing body 510. Furthermore, an image combining circuit (not shown) is provided in the camera housing 500.

[53] The main camera module 200, which is commercially sold, is installed in the camera housing 500, explained above with reference to FIG. 4, and, thereafter, an image signal wire (not shown) of the main camera module 200 is connected to the image combining circuit, thus forming the pan/tilt camera apparatus of the present invention.

[54] FIG. 5 is a view showing a protective frame 130, which is mounted to the camera housing 500 of FIG. 4 to protect the auxiliary camera module 100. The protective frame 130 is mounted to the first and second surfaces 122a and 122b of the camera mounting frame 120 of the auxiliary camera module 100. The protective frame 130 has openings 132, through which views for the lens units 112a and 112b are ensured. In the present invention, because the camera housing 100 has the above-mentioned structure, the auxiliary camera module 100 is prevented from being damaged by outside factors such as the weather. Of course, those skilled in the arts will be able to easily appreciate that the protective frame 130 may be integrally manufactured with the camera mounting frame 120 of the auxiliary camera module 100.

[55] FIG. 6 is a view showing a pan/tilt camera apparatus having an auxiliary camera, according to another embodiment of the present invention.

[56] Referring to FIG. 6, the pan/tilt camera apparatus according to this embodiment of the present invention includes a pan drive shaft 430, which is supported on a support column 440 and rotates around the same rotating axis as that of the support column 440, and a tilt arm 420, which is tiltably coupled to the pan drive shaft 430. The tilt arm 420 is coupled to the pan drive shaft 430 using a shaft 410.

[57] Furthermore, a camera housing 500 is mounted to the tilt arm 420. The camera housing 500 has camera receiving space therein, and a main camera module 200 and an image combining circuit unit 300 are provided in the receiving space.

[58] Unlike the camera apparatus shown in FIG. 1, in the camera apparatus of this embodiment of the present invention, auxiliary camera modules 100b and 100c are mounted to the pan drive shaft 430. In detail, the two auxiliary camera modules 100b and 100c are mounted to the pan drive shaft 430. Each of the auxiliary camera modules 100b and 100c has two cameras 110a and 110b, which are disposed in the same manner as the cameras explained above with reference to FIGS. 2 and 3.

[59] Although the auxiliary camera modules 100b and 100c have been explained as being mounted to the pan drive shaft 430, those skilled in the art will appreciate that the auxiliary camera modules 100b and 100c may be mounted to the support column 440. FIG. 7 shows auxiliary camera modules lOOd and lOOe mounted to a support column 440.

[60] FIG. 8 is a view showing an enlargement of one auxiliary camera module of FIG. 6.

[61] Referring to FIG. 8, the auxiliary camera module 100b is installed in an opening, which is formed at a predetermined position in the pan drive shaft 430. Therefore, the auxiliary camera module 100b is rotated along with rotation of the pan drive shaft 430. In this embodiment, the auxiliary camera module 100b may not be installed in the opening of the pan drive shaft 430, that is, it may be attached to the outer surface of the pan drive shaft 430.

[62] In this embodiment, the auxiliary camera module 100b is tiltably mounted to the pan drive shaft 430. For this, the pan drive shaft 430 has therein a tilt drive unit 600, which includes a drive motor, a reducer and a power conversion device for converting the rotation of the motor into linear motion, and a tilt arm 610, which is coupled between the tilt drive unit 600 and the auxiliary camera module 100b to tilt the auxiliary camera module 100b.

[63] According to this embodiment, the auxiliary camera modules are tiltably mounted to the pan drive shaft 430 at opposite positions, so that surveillance in the direction opposite to the surveillance direction of the main camera can also be conducted. In other words, there is an advantage in that all directions through 360° can be under the surveillance of the camera apparatus.

[64] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, these are not limited to the present invention, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. For example, in the above-mentioned preferred embodiments, the auxiliary camera module includes two cameras, but the number of cameras constituting the auxiliary camera module is not limited to this. To observe a wider area or to ensure superior image quality, three or more cameras may be provided in the camera module. These modification and additions must be regarded as falling within the bounds of the present invention disclosed in the accompanying claims. Industrial Applicability

[65] As described above, the pan/tilt camera apparatus of the present invention overcomes the limits of the conventional pan/tilt camera apparatuses. For example, because the present invention provides a wider surveillance area to a supervisor, a main camera can be rapidly oriented towards a trespass area, thus efficiently responding to a trespassing action.

[66] Furthermore, an auxiliary camera module for expansion of the view of the main camera includes two or more cameras, and images obtained by the cameras can be displayed on a screen without being processed by particular software.

[67] As well, in the pan/tilt camera apparatus of the present invention, the auxiliary camera module may be provided in an existing housing, in which the main camera module is installed. In this case, the housing having the auxiliary camera module therein can be simply connected to the main camera at a site. As such, because no special effort is required to install the housing, work at a site is convenient.

Claims

[1] A pan/tilt camera apparatus for observing a surveillance area, having a camera module, an image combining circuit unit and a pan/tilt drive unit, the pan/tilt camera apparatus comprising: an auxiliary camera module operating in a direction in which a main camera module scans, and scanning a large area including an imaging area of the main camera module, the auxiliary camera module comprising two cameras disposed such that two adjacent image incidence lines of the cameras are parallel to each other; a camera mounting frame having first and second surfaces angled at a predetermined angle, with through holes formed in the respective first and second surfaces of the camera mounting frame so that lens units of the cameras are disposed in the respective through holes; and a camera housing having a receiving space for receiving the main camera module, the auxiliary camera module and the image combining circuit unit therein and an opening for ensuring vision of the main and auxiliary camera modules.

[2] The pan/tilt camera apparatus according to claim 1, wherein each of the two camera lens units has an optical distortion rate of 15% or less.

[3] The pan/tilt camera apparatus according to claim 1, wherein the auxiliary camera module is provided in a pan drive shaft and comprises auxiliary camera modules, each of which has two cameras disposed such that two adjacent image incidence lines of the cameras are parallel to each other.

[4] The pan/tilt camera apparatus according to claim 3, wherein the auxiliary camera modules are provided in the pan drive shaft at opposite positions.

[5] The pan/tilt camera apparatus according to claim 3 or 4, wherein each of the auxiliary camera modules comprises a camera mounting frame having first and second surfaces angled at a predetermined angle, with through holes formed in the respective first and second surfaces of the camera mounting frame so that lens units of the cameras are disposed in the respective through holes.

[6] The pan/tilt camera apparatus according to claim 1, further comprising: a protective frame having an opening and mounted to the camera housing to protect the auxiliary camera module.

[7] The pan/tilt camera apparatus according to claim 1, wherein a protective cover is provided on an upper surface of the camera housing.