WO2001010129A1

WO2001010129A1 - A multi-purpose and compact camera system including infrared emitters and cameras

Info

Publication number: WO2001010129A1
Application number: PCT/US2000/017871
Authority: WO
Inventors: Augie K. Fabela; W. Herbert Halcomb
Original assignee: Insight Technologies, Inc. Dba Scopus Optoelectronic Systems
Priority date: 1999-07-29
Filing date: 2000-07-31
Publication date: 2001-02-08
Also published as: AU6489100A

Abstract

A compact surveillance system with IR emitters and at least one camera (22), which can efficiently provide clear and precise video images. A heat sink element (12) removes heat, generated by the at least one infrared light emitting unit (24), away from the camera assembly.

Description

A MULTI-PURPOSE AND COMPACT CAMERA

SYSTEM INCLUDING INFRARED EMITTERS

AND CAMERAS

BACKGROUND OF THE INVENTION

The present invention relates generally to a camera More specifically, the present invention relates to a compact dual-purpose camera having camera and infrared (IR) emitters

It is known to use conventional video cameras for vaπous purposes including performing surveillance of vaπous locations of interest (e.g., financial institutions, public shopping centers, private rooms, etc.) Many of these video cameras are able to continuously produce images as long as there is adequate light. Some surveillance systems are able to alter the type of video being utilized based upon such factors as lighting and the time of day. Typically, black-and-white cameras generally require much lower light levels than color cameras. Thus, some surveillance systems employ both black-and-white video cameras (for low light) and color cameras (for higher light levels) because of the greater amount of information available therefrom. For example, U.S. Patent No. 5,172,220 descπbes a system that includes a color video camera and a black and white video camera for use in surveillance When the level of light exceeds a threshold value, a switch causes a reflector to be pivoted from one video camera to the other.

Also, there has been a constant effort to obscure surveillance systems from the general public. This is done so that actual behavior can be observed without the knowledge of the person under surveillance As a result, surveillance systems have become smaller and more centralized. However, the conflicting requirements of compactness and the heat dissipation required for such systems have caused the industry to reach a point of diminishing returns with respect to the reduction in size of the systems.

For example, conventional infrared emitters and cameras have been employed to detect and monitor unexplained occurrences of heat within the location of interest However, a reliable and accurate compact system utilizing both IR monitoring and video monitoring has not been achieved due to the fact that a great deal of heat is generated by IR emitters. Conventionally, using IR emitters in a small and compact area with any type of camera would only lead to the destruction of the camera due to the high power output of the IR emitters. Thus, there is an unsolved need for a compact surveillance system that enables the efficient use of IR emitters in combination with a camera.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a compact camera system with both IR emitters and at least one camera, which can efficiently provide clear and precise video images.

It is another object of the present invention to enhance the quality of images from a black and white camera system in low light levels.

It is yet another object of the invention to improve heat dissipation in a camera system.

It is yet another object of the invention to reduce the size of a camera system having both color and IR video camera systems.

Thus, in accordance with one exemplary embodiment of the present invention, a surveillance camera assembly is disclosed which comprises at least one video camera, at least one infrared light-emitting unit and a heat sink element directly connected to the at least one infrared light-emitting unit. The heat sink element conducts heat, generated by the at least one infrared light emitting unit, away from the camera assembly.

In accordance with another exemplary embodiment of the present invention an infra red emitter assembly is disclosed which comprises a first subassembly and a second subassembly including a heat sink. The second subassembly is joined to the first subassembly to form an outer shell. At least one infrared light-emitting unit is connected directly to the heat sink element. In accordance w ith another exemplary embodiment of the present invention, a camera apparatus including both black and white and color video surveillance cameras is disclosed The apparatus comprises a black and white video camera, a color video camera, a sensor for detecting the brightness of the environment, at least one infrared light-emitting unit, and a control circuit for activating and deactivating the black and white video camera, the color video camera and the at least one infrared light-emitting unit based upon the sensed brightness of the environment

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be understood more completely b reading the following Detailed Descπption of exemplary embodiments of the invention, in conjunction with the accompanying drawings, in which

FIG 1 is an isometπc view of a camera assembly according to an exemplary embodiment of the present invention,

FIGS 2 and 3 are cross sectional views of the camera assembly illustrated in FIG 1 in accordance with exemplary embodiments of the present invention,

FIGS 4 and 5 are isometric views of the rear assembly of the exemplary embodiments of the present invention,

FIGS 6 and 7 are front and side views, respectively of an infrared optical emitter in accordance with the embodiments of the present invention,

FIG 8 is a side view of a lens device in accordance with an exemplary embodiment of the present invention,

FIG 9 is a side view of the lens device illustrated in FIG 8 in combination with the infrared optical emitter illustrated in FIGS 6 and 7, in accordance with an exemplary embodiment of the present invention,

FIG 10 is a side view of a lens device in accordance with an exemplary embodiment of the present invention, FIG 1 1 is a side view of the lens device illustrated in FIG 10 in combination with the infrared optical emitter illustrated in FIGS 6 and 7, in accordance with an exemplary embodiment of the present invention,

FIG 12 is a side view of the lens device illustrated in FIGS. 8 and 10 in combination with the infrared optical emitter illustrated in FIGS. 6 and 7, in accordance with an exemplary embodiment of the present invention;

FIG. 13 is a control circuit used to control operation of multiple cameras used in the camera assembly of an exemplary embodiment of the present invention;

FIG. 14 is a LED circuit used in combination with the control circuit of FIG. 13 to control operation of multiple cameras used in the camera assembly of an exemplary embodiment of the present invention; and

FIG. 15 is a graphical representation illustrating the control timing of the cameras in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be descπbed with reference to the accompanying drawings, in which vaπous exemplary embodiments of the invention are shown. However, this invention may be embodied in many different forms and should not be construed as limited to the specific embodiments shown.

An isometπc view of a camera assembly 10 is shown in FIG. 1, in accordance with an exemplary embodiment of the present invention. The camera assembly 10 compπses two subassemblies: a rear assembly 12 and a front assembly 14 that, when joined together (e.g. by screws) forms the outer shell of the camera assembly. The front assembly 14 can be made from a hard plastic mateπal while the rear assembly 12 can be made from cast aluminum. While aluminum is the preferred material used for the rear assembly 12, other mateπals can be employed as long as the heat transfer characteπstics of the mateπal enable efficient operation of cameras within the camera assembly 10 The exteπor of the rear assembly 12 includes a plurality of heat transfer fins 11 that enable the conduction of generated heat away from the camera assembly 10. The front assembly 14, includes a plurality of lens housings 15, 16, 17 and 18 that hold lenses for various cameras and infrared (IR) emitters, as described below. The compact size of the camera assembly 10 produces a compact camera system that is not obtrusive The size of the camera assemblylO is approximately 2.8 inches wide by approximately 3.49 inches high by approximately 3.49 inches in length.

A side view of camera assembly 10 is shown in FIG. 2, in accordance with an exemplary embodiment of the present invention. A black and white video camera 22 (which can detect infrared wavelengths as well as visible light) is situated within the assembly so that the camera lens faces out from lower lens housing 15. An IR emitter 24 and its associated lens assembly 25 is situated within the assembly so that the emitter faces out of the lens housing 18. An IR emitter 24 is also located in lens housing 16 to provide additional IR emissions for reception by the black and white video camera 22.

Also, as illustrated in FIG. 2, an aluminum heat transfer post 20 abuts against the rear of the IR emitter 24. The direct contact between the IR emitter 24 and the heat transfer post 20 provides a conduit through which heat, generated by operation of the IR emitter 24, is removed from the front of the camera assembly 10 to the rear of the camera assembly 12. The heat transfer fins 11 coupled to the heat transfer port 20 are further able to affect transfer of the generated heat away from the camera assembly 10 itself.

As illustrated in FIG. 3, a color video camera 31 is situated adjacent to lens housing 17. Having both the color video camera 31 and a black and white video camera 22 within the housing enables clear image detection in a wide variety of ambient light levels in the manner described below. In another exemplary embodiment of the present invention, the camera assembly 10 may include only a single black and white video camera 22, situated adjacent to the lower lens housing 15. Thus, if the color video camera 31 is removed, a third IR emitter 24 can be placed into lens housing 17 to provide an additional emitting capability thereby increasing the quality of the video output of the black and white video camera 22. In yet another exemplary embodiment of the present invention, either two or three IR emitters 24 can be employed, without any accompanying camera, and be utilized as a high powered IR emitter array IR emitter 24 and black and white video camera 22 can be controlled in concert, I e activated and deactivated in a simultaneous manner

An isometric iew of the rear assembly 12 is shown in FIGS 4 and 5 In accordance with an exemplary embodiment of the present invention, the rear assembly 12 comprises a set of posts 20, made of cast aluminum, for example, which are used to abut against IR emitters 24 The posts are made in an hourglass shape to effect efficient removal of heat from the IR emitters and to reduce the expense and weight of the camera assembly 10 through efficient utilization of mateπal The embodiment illustrated in FIG 4 represents the rear assembly 12 when employing three IR emitters 24 Each IR emitter 24 has a post abutting against it As illustrated in FIG 5, the rear assembly 12 includes two posts 20, made of cast aluminum, for example, which are used to abut against IR emitters The center post is removed so that a camera can be placed into the upper center lens housing 17 (See also FIG 3)

FIGS 6 and 7 show front and side views, respectively, of an IR emitter 24 in accordance with an exemplary embodiment of the present invention As discussed above, an IR emitter 24 enables IR light to be used to illuminate a sense duπng low ambient light levels The IR emitter 24 compπses an array of eighteen (18) light emitting diodes (LEDs) 60 Fifteen of the LEDs are placed in a three by five matπx wherein the cathode of an LED faces the anode of the neighboπng LED Three additional LED devices are placed across the top of the matπx of 15 LEDs wherein the cathode of an LED faces the anode of the neighbonng LED The matπx of 18 LEDs 60 is located on a substrate 62 (e g , a BeO substrate) The LEDs are attached to a header device 64 and placed within the camera assembly A cathode 66 and an anode 68 are each connected via hard wire (e g , gold wire) to a voltage supply and associated control circuit, discussed below As illustrated in FIG 7, the matπx of

LEDs 60 is encapsulated by an epoxy 70

FIG 8 illustrates, in detail, a lens 80 that, in accordance with exemplary embodiments can be used as the lens assembly 25 descπbed in FIG 2 Lens 80 compnses two individual lens elements placed on opposing sides of a transparent plastic member 86 Lens element 82 has a radius of curvature of approximately 1 0 cm while lens element 84 has a radius of curvature of approximately 1 378 cm When the lens 80 is employed as the lens assembly 25 for the lens emitter 24, as illustrated, for example, in FIG 9, a 60-degree field of illumination is provided The lens 80 can be made of glass, acrylic or polycarbonate, for example However, one of ordinary skill would understand that other lens mateπals could also be employed

FIG 10 illustrates, in detail, a lens 100 that, in accordance with exemplary embodiments can be used as the lens assembly 25 descπbed in FIG 2 Lens 100 compπses two individual lenses elements placed on opposing sides of a transparent plastic member 106 Lens elmentl02 has a radius of curvature of approximately 1 772 cm while lens element 104 has a radius of curvature of approximately 3 937 cm When the lens is employed as the lens assembly 25 for the lens emitter 24, as illustrated, for example, in FIG 1 1, a 90-degree field of illumination is provided The lens 100 can be made of glass, acrylic or polycarbonate, for example However, one of ordinary skill would understand that other lens mateπals could also be employed

Additionally, FIG 12 illustrates a combination of the lens 80 and the lens 100 employed to obtain a 30-degree field of illumination The front lens 100 is subject to weatheπng since plastic is susceptible to scratching However, in accordance with the exemplary embodiments of the present invention the operating characteπstics of the camera will not be altered due to the fact that the lens assembly is being used for infrared light The longer wavelength of infrared light does not give πse to scatter, unlike visible light A hard coating can be placed onto the front surface of the lens to reduce scratching

In accordance with an exemplary embodiment of the present invention, diagrams of the camera assembly control circuitry are shown in FIGS 13-15, wherein the color video camera 31 and black and white video camera 22 are employed When both video cameras are employed the control circuit 130 allows the switching between the use of each video camera based upon the bπghtness of the environment In accordance with one exemplary embodiment, the use of a potentiometer 132 enables the selection by a user of the light levels at which the one camera will stop being utilized video and the other begin being utilized Sensor 131 (e.g., a photodiode) detects the ambient light level (i.e., brightness). Based upon the brightness detected and the threshold set at the potentiometer 132, either a high or low signal is produced by the comparator circuit 133. The output of the comparator circuit 133 is sent directly to comparator circuits 134 and 135. Comparator circuits 134 and 135 are each respectively connected directly to switches 137 and 138. Additionally, comparator circuit 135 is also connected to a relay 136. Switches 137 and 138 provide 12 Volts DC voltage to activate the color video camera 31 and the black and white video camera 22, respectively. The video output of each camera is connected to a common output via switch 139 associated with relay 136.

FIG. 14, illustrates a circuit 140 that provides a voltage supply (e.g., either 12V or 24V DC) to the LEDs 60, in accordance with an exemplary embodiment of the present invention. The LEDs 160 are connected, via signal processing and conditioning circuitry 142 to a DC voltage source. When the black and white video camera 22 is in operation, switch 143 is closed so that voltage is supplied to the LEDs

60. Additionally, in another exemplary embodiment of the present invention, the camera assembly 10 of the present invention can also include a microphone for the reception and possible recording of audio.

Assuming a dark ambient light level, below the threshold set in the potentiometer 132, a low output signal is generated in the comparator circuit 133.

This low output is sent to comparator circuits 134 and 135. The resulting output to of comparator circuits 134 and 135 is high and low, respectively. As such the relay 136 is not opened and switch 138 supplies voltage to the black and white video camera 22. With reference to FIG. 13, power is also supplied to LEDs 60 to illuminate the field of view in as invisible manner. When the output of comparator circuit 134 is high, switch 137 does not supply voltage to the color video camera 31.

On the other hand, when a light environment is detected, a high output signal is generated at the comparator circuit 133. The resulting output to of comparator circuits 134 and 135 is low and high, respectively. As such the relay 136 is opened and switch 138 no longer supplies voltage to the black and white camera. With reference to FIG. 13, power is also no longer supplied to LEDs 60. When the output of comparator circuit 134 is low, switch 137 supplies voltage to the color video camera 31.

In accordance with another exemplary embodiment of the present invention, the control circuit can be adjusted so that there is an overlap in time or light levels in which both the color video camera 31 and black and white video camera 22 are activated through a forced hysteresis effect. Specifically, to prevent premature switching from one camera to the other (e.g. from the color video camera 31 to the black and white video camera 22) at dusk conditions or the like, a hysteresis technique is employed. Comparator 135 changes states based on previous light conditions. Negative feedback is accomplished by use of resistors R12 and R13 to control the status of comparator 135 to achieve the desired hysteresis effect. As illustrated in FIG. 15 the hysteresis effect causes operation of the camera to overlap thus avoiding erratic operation at light levels close to the transition threshold. Alternatively, a time delay can be placed into the control circuit so that both cameras are simultaneously operating. For example, during the transition from light to dark, the activation of the relay can be delayed so that after a time delay (e.g., 3 seconds) the black and white video camera 22 is activated. Next, a certain amount of time after activation of the black and white video camera 22 (e.g. 5 seconds) the color video camera 31 is turned off. Also, during the transition from dark to light the relay can be employed to enable both cameras to be activated at the same time. For example, after a time delay (e.g., 3 seconds) the color video camera 31 is activated then a certain amount of time after activation of the color video camera 31 (e.g. 5 seconds) the black and white video camera 22 is turned off.

Any number of type of camera can be used. Any type of IR emitter can be used. The housing can take various shapes and forms. Control of the invention can be accomplished through any means, such as a microprocessor based device, hardwired analog logic, or the like. The camera assembly can be sued in various applications. Various lenses and other optical elements can be employed to achieve desired optical effects. The heat sink element can be a single unitary structure or a combination of elements. While the present invention has been descπbed with respect to its preferred exemplary embodiment, those skilled in the art will recognize that the present invention is not limited to the specific embodiment described and illustrated herein Different embodiments and adaptations besides those shown herein and descπbed as well as many vaπations, modifications and equivalent arrangements will no be apparent or will be reasonably suggested by the foregoing specification and drawings, without departing from the scope of the invention as defined by the appended claims and legal equivalents

Claims

WHAT IS CLAIMED IS:

1. A surveillance camera assembly, comprising:

at least one video camera;

at least one infrared light-emitting unit; and

a heat sink element directly connected to said at least one infrared light-emitting unit, wherein said heat sink element removes heat, generated by said at least one infrared light emitting unit, away from said camera assembly.

2. The surveillance camera assembly of claim 1 , wherein said at least one infrared light-emitting unit further comprises an array of light emitting diodes placed and a lens device.

3. The surveillance camera assembly of claim 2, wherein said lens element provides at least one of a 30-degree, 60-degree or 90-degree beam angle.

4. The surveillance camera assembly of claim 1, wherein at least one of said at least one video camera is a black and white video camera.

5. The surveillance camera assembly of claim 1, wherein said heat sink element comprises a post.

6. The surveillance camera assembly of claim 5, wherein said post is aluminum.

7. The surveillance camera assembly of claim 1, wherein said heat sink element comprises a combination a post and fin elements.

8. The surveillance camera assembly of claim 5, wherein said post is aluminum.

9. A light-emitting assembly comprising: a first subassembly,

a second subassembly including a heat sink, said second subassembly being joined to said first subassembly to form an outer shell, and

at least one infrared light-emitting unit connected directly to said heat sink element

10 The light-emitting assembly of claim 9, wherein said at least one infrared light-emitting unit further compπses a plurality of light emitting diodes placed in an array and a lens device

11 The light-emitting assembly of claim 10, wherein said lens element provides at least one of a 30-degree, 60-degree or 90-degree beam angle

12 The light-emitting assembly of claim 9, wherein at least one of said at least one video camera is a black and white video camera

13 The light-emitting assembly of claim 9, wherein said heat sink element compnses a combination an aluminum post and fin elements

14 A camera apparatus including both black and white and video surveillance cameras compπsing

a black and white video camera,

a color video camera,

a sensor for detecting the bπghtness of said environment,

at least one infrared light-emitting unit, and

a control circuit for activating and deactivating said black and white video camera, said color video camera and said at least one infrared light- emitting unit based upon the sensed bπghtness of said environment

15 The camera apparatus of claim 14, wherein said control circuit compπses means for sensing ambient light levels, means for setting a threshold, and means for selectively activating said black and white video camera, said at least one infrared light emitting unit and said color video camera based on the ambient light level and the threshold

16 The camera apparatus of claim 15, wherein said mean for selectively activating includes means for imparting a hysteresis effect to said control circuit to activate said color video camera and said black and white video camera in an overlapping manner based on previous levels of ambient light detected by said means for sensing

17 The camera apparatus of claim 15, wherein said means for selectively activating includes means for introducing a time delay to said control circuit to activate said color video camera and said black and white video camera in an overlapping manner

18 The camera apparatus of claim 14, wherein said control circuit activates and deactivates said black and whited video camera and said at least one infrared light emitting unit in concert

19 The camera apparatus of claim 15, wherein said control circuit activates and deactivates said black and whited video camera and said at least one infrared light emitting unit in concert

20 The camera apparatus of claim 16, wherein said control circuit activates and deactivates said black and whited video camera and said at least one infrared light emitting unit in concert

21 The camera apparatus of claim 17, wherein said control circuit activates and deactivates said black and whited video camera and said at least one infrared light emitting unit in concert

22 The camera apparatus of claim 18, wherein said control circuit activates and deactivates said black and whited video camera and said at least one infrared light emitting unit in concert