JPS6324765A - Image pick-up device - Google Patents

Abstract

PURPOSE:To eliminate the need for providing separately a camera for supervising and an infrared ray detecting part for detecting a human body when a supervising system is used by providing an optical filter before a CCD imager and making a part of the optical filter into the infrared ray detecting part. CONSTITUTION:The light wade incident on a CCD imager 21 through an optical filter 22 having an infrared ray transmitting part IR is made into an image output and supplied to a processing circuit 23. From a sampling hold circuit 231, an infrared ray detecting output is obtained, from a sampling hold circuit 232, a luminance signal SY is obtained respectively, and a signal SY is supplied to an omission interpolating circuit 26. The output of the circuit 231 is supplied to a trigger signal forming circuit 27, when a human being enters the inside of the view angle of a camera, the change of the infrared ray detecting output is detected, a trigger signal TG is obtained and thus, a VTR 2 is made into a recording condition and the signal SY is recorded for a constant time in a tape.

Description

[Detailed description of the invention] This invention will be explained in the following order.

A. Field of industrial application B. Outline of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem F. Effect G. Example G1 Figure) G2
Embodiment of Color Imaging Apparatus (FIGS. 6-1 to 8) H Effects of the Invention A Field of Industrial Application This invention relates to an imaging apparatus suitable as an imaging apparatus used, for example, in a surveillance system.

B. Summary of the Invention This invention provides an optical filter provided in front of a CCD imager with a portion having an infrared selection characteristic, whereby an imaging signal mainly detected in visible light and a detection signal detected mainly in infrared light are separated. can be obtained from the same CCD imager, and has the effect that infrared light from the imaging subject can be obtained through the same optical system as the imaging output.

C. Prior Art Conventionally, a surveillance system combining a video camera and a VTR has been installed in, for example, a cash service corner of a financial institution to monitor the coming and going of people.

An example of such a surveillance system is to detect infrared rays emitted from the human body to detect when a person enters or exits, and to monitor a video camera for a certain period of time after the person enters or while the person is present. It is known to record the output on a VTR.

Figure 9 shows the configuration of an example of this type of surveillance system, where (1) is a video camera, (2) is a VTR, +31 is an infrared sensor, and the infrared radiation from the human body (4) as a subject is infrared rays. When detected by the sensor (3), the trigger signal TO from this infrared sensor (3) causes the VTR
(21 is in a recording state, and the video signal Vl from the video camera (1) is recorded on the tape for a certain period of time after the human body is detected or while the human body is being detected.

By the way, in the case of the system shown in FIG. 9, although it can be constructed using an infrared sensor in a simple configuration and at a relatively low cost, it has a drawback in that the infrared sensor needs to be installed separately from the video camera. Furthermore, it was necessary to match the angle of view of the video camera and the sensing range of the sensor unit, but since both were units made by Oki Hardware, it was difficult to make this adjustment and required a large amount of man-hours. Furthermore, since the above ranges do not necessarily match, there are problems such as one person being detected but not being photographed, or the sensor not detecting a person even though it is supposed to be within the angle of view of the video camera.

Therefore, the camera output Vl and the recording trigger signal TG of the VTR (2) are obtained from within the same unit.
In other words, it has been considered to obtain the information from the imaging device.

FIG. 10 shows an example of a monitoring system using an example of such an imaging device. (5) shows the imaging device as a whole, and inside this imaging device (5) there is a video camera section (6) as well as an image capturing device. An image processing section consisting of a comparison circuit (8) and a waveform shaping Schmitt circuit (9) is provided.

In the memo (January 7), write a captured image (still image) of the location where the imaging device (5) is installed when no humans or the like are present. And the video camera section (6
)Yori no Ei@! The comparison circuit (8) compares the signal Vl and the still image signal SV from this memo (January 7), and supplies the comparison output to the Schmitt circuit (9) for waveform shaping. This is to obtain a recording trigger signal of 1゛G for VTR+2).

That is, when a person enters both corners of the camera (1), the comparator circuit (6) detects the presence of the person as a difference from the still image, and the difference is supplied as a trigger signal to the VTR (2). Camera (1) output image @! Signal Vl is V T
R (21) is recorded on the tape in the same manner as in the example in FIG.

According to the example in FIG. 1O, the imaging output and VTR(2+
Since the recording trigger signal ``C'' can be obtained from the imaging device (5), there is no drawback as in the example in Fig. 9, but the circuit size is large because the image processing section requires an image memory, etc. The disadvantage is that it is expensive.

Therefore, it has been considered to use an infrared sensor as the human body detection sensor and to incorporate the sensor section into the imaging device as shown in the example shown in FIG. This technology uses a common optical system for the video camera and the infrared sensor, and uses a half mirror to separate the infrared light and the rrJ viewing light for imaging (Japanese Patent Laid-Open No. 55-2363
See Publication No. 1: Note that this minute axis relates to an invention regarding an infrared autofocus mechanism. ) could be considered.

FIG. 11 is a diagram showing an outline of a monitoring system using this improved imaging device, where (10) shows this imaging device as a whole, and the infrared sensor (13) is connected to this imaging device i! (1
0). (11) is an imaging lens, (12)
is a CCD imager, and (14) is a half mirror.

In this configuration, the subject light that has passed through the imaging lens (11) passes through the half mirror (14) and the CCD imager (
]2), and an imaging signal is obtained from this CCD imager (12). In addition, in this case, a half mirror (1
In 4), the characteristics of the reflective layer are matched to the wavelength of infrared rays emitted from the human body, and the infrared rays of the incident light that passes through the imaging lens (11) are reflected by this half mirror (14) and enter the infrared sensor (13). do. However, IM@!
When a person enters the field of view of the imaging lens (11) of the device (10), the infrared rays emitted by this person are detected by the infrared sensor (1
3), a trigger signal TG is supplied to the VTR+21, and the VTR+21 enters the recording state, and at this time, the image output Vl imaged on the CCD imager (12) is recorded on the tape.

According to the improved example shown in FIG. 11, compared to the example shown in FIG. Since the optical system is the same as that of the other parts, the angles of both sides almost match, and there is no need to adjust the angles of both sides.

D Problems to be Solved by the Invention However, in the case of the example shown in FIG. 11, it is necessary to specifically provide a half mirror, and it is necessary to provide an imager and a sensor section for each of the camera section and the infrared detection section. There is a drawback that it must be done.

The present invention aims to provide an imaging device that can eliminate this drawback.

E Means for Solving Problems 1 In this invention, a CCD imager and a CCD imager are used.
An optical filter is provided on the front side of the imaging section of the imager and has an infrared light detection section formed in a part thereof, and the imager is equipped with an optical filter in which an infrared light detection section is formed. Infrared light detection output is obtained.

The F action optical filter is provided with an infrared detector, and the infrared rays that have passed through the infrared detector are incident on the CCD imager. Visible light that has passed through the portion of the optical filter other than the infrared detection section also enters the CCD imager and forms an image. Therefore, the CCD imager provides an infrared light detection output as well as an imaging output. Then, by sampling the output from the imager position corresponding to the infrared detection section of the optical filter, this infrared detection output can be easily separated from the output of the CCD imager.

G Example G1 Example of Monochrome Imaging Apparatus Figure 1 is an example of this invention/apparatus, and this example is a monochrome image capturing apparatus. This is a case where the signal is obtained as an imaging output.

In FIG. 1, (21) is a CCD imager, and an optical filter (22) is provided in front of the imaging surface of this CCD imager (21). This optical filter (22)
is constructed by arranging a filter element having wavelength selectivity for each pixel of the CCD imager (21), but in this example, it covers the entire area within the range of all pixels of the CCD imager (21). The random pixel areas (or clusters of multiple pixels) shown with diagonal lines in FIG. Ru. The filter elements for other pixel parts are made to have wavelength selectivity so as to transmit visible light. In this case, it is not necessary to provide so many infrared light transmitting parts IR for all pixels. This is because infrared light detection information does not require any image information. Therefore, it is convenient if the ratio between the amount of the infrared light transmitting section and the amount of the visible light transmitting section is set to an appropriate ratio such that the omission of information in the infrared light transmitting section is not noticeable as image information.

Furthermore, when a human monitors an image, as described in 1 & above, if interpolation is performed using the horizontal or vertical correlation of the video signal, the unsightly 1M@! There is no such thing as that.

CC through the optical filter (22) with the above characteristics.
The light incident on the D imager (21) is photoelectrically converted into a ζ image output and supplied to the process circuit (23).

This process circuit (23) includes a sampling and hold circuit (231) that takes out the signal output from the pixel part where infrared light enters through the infrared light transmitting part IR, and a signal output from the pixel part where other visible light enters. A sampling and holding circuit (232) for taking out the image information output is provided, and a sampling signal is supplied from the timing signal optical circuit (24), respectively. (25) is a CCD imager (21)
@red portion IP facing the infrared light transmitting portion IR of the filter (22) in all pixels, and pixel portion v facing the visible light portion
This is a memory that stores position information with p. The position (number g) is written in advance in this memory (25) as follows. That is, only infrared light is incident over the entire surface of the optical filter (22). Then, the infrared light transmitting part IR
The infrared light detection output is obtained only from the corresponding pixel. "1" is written to the address of the memory (25) corresponding to the pixel position where this infrared light detection output was obtained, and "0" is written to the address of the memory (25) corresponding to the other pixel positions. It will be done.

Then, position information is read out from this memory (25) at the same time as the pixel output of the CCD imager (21), and the position information is supplied to the timing signal forming circuit (24). In this case, memo IJ (25) contains rii
? Since the position information is written as described above, it is "1" for the pixel part IP, and "0" for the pixel part ■P.
is read out as position information, and the timing signal forming circuit (24) sends a sampling pulse SPL to the sampling hold circuit (231) for position information "1".
is output, and for position ;l information "0", a sampling pulse SP2 is output to the sampling hold circuit (232).

Therefore, the sampling hold circuit (231) outputs the output from the pixel portion IP, that is, the infrared light detection output SI.
The output from the pixel portion VP, that is, the luminance signal sy, is obtained from the sampling and hold circuit (232).

The signal SY is then supplied to the missing interpolation circuit (26). This interpolation circuit (26) includes a timing signal forming circuit (
24) The interpolated position information SP3 is supplied from pixel portion I.
For example, if the signal missing part in the output SY of the P part is 1
It is replaced with information from the previous horizontal period and interpolated with "ζ".

The signal SY' thus interpolated is supplied to the VTR (21) as an output of this imaging device.

In addition, the output SI of the sampling hold circuit (231)
R is supplied to the trigger signal forming path (27). In this trigger signal forming circuit (27), the infrared light detection output SIR
is differentiated by a differentiating circuit (28), and the differential output is sampled and held by a sampling and holding circuit (29). The differentiation circuit (28) detects a change in the infrared light detection output when a person enters the camera's field of view from a state where there is no person within the field of view. Then, the detection output is sampled and held in a sampling and holding circuit (29) in synchronization with the output position from the pixel portion IP to form a trigger signal.

In this way, the differentiating circuit (28) and the sampling and holding circuit (29) distinguish between changes in infrared light caused by the environment, such as in the morning and evening, and changes in infrared light caused by a person entering the interior angle. The desired trigger signal TO is (raised,
As a result, the VTR (21) is put into the recording state and the signal S
Y' is recorded on the tape for a certain period of time.

Furthermore, since the change when a person disappears from within the interior angle of the camera can also be detected with a differential cycle of 1/8 (2B), a trigger that puts the VTR (2+) in the recording state while the person remains within the interior angle can be detected. You can also get a signal.

Note that the above example uses a specific random r! within the effective pixels among all pixels of the CCD imager. ! This is a case where the filter part corresponding to the ll pixel part is set as the infrared light transmitting part IR, but the CCD imager invalidates some @acid parts outside the effective pixel as shown with diagonal lines in Fig. 3. It has a pixel area (40), and generally this invalid area (40
) is provided with an optical black mask to prevent it from being used, but this invalid area (40) may be used as an infrared light transmitting section.

In this case, the memory (25) has this invalid area (40
) of l! For the 1i element, write "1" as a position signal, and for the pixel in the valid area, write "10" as the position signal, and infrared light is detected as the imaging output from the pixel in the invalid area (40). Get the output.

When this is done, there is no loss in the luminance signal due to the pixel portion IP, so interpolation for that purpose becomes unnecessary. However, is the signal missing due to a defect in the CCD imager itself? +Ii is carried out in the same way as in the normal case. Since this signal loss due to a defect in the CCD imager itself is unique to each element, the position of the defective part is written in memory, and the output information of that pixel position is obtained by interpolating in the same manner as described above. It is.

Note that if a person enters the camera's field of view from either the top, bottom, left or right direction, an invalid area (
40) may be used as the infrared light transmitting part, but if we consider a case where, for example, the door through which people exit is located in the center of the camera's field of view, as shown in Fig. 4, It is better to use both filter parts corresponding to random pixel positions among valid pixels as infrared light transmitting parts and using the invalid area (40) as infrared light transmitting parts as shown in FIG. 3, as shown in FIG.

Furthermore, the trigger signal forming circuit (27) may be of the type shown in FIG.

That is, the infrared light detection output S from the processor (23)
A change in IR is detected by a differentiating circuit (31), this differential output is sampled and held by a sampling and holding circuit (32), and this held output is supplied to one input terminal of a comparing circuit (33). In addition, infrared light detection output SIR
is integrated in an integrator circuit (34), and the integrated output is sampled and held in a sampling and hold circuit (35) to obtain an infrared amount corresponding to changes in the environment, which is then supplied to a comparison circuit (33). Then, the differential output supplied to one input terminal is subtracted from the sampling hold output to remove the influence of environmental changes.

In this way, from comparison circuit 123 (33), changes in the infrared light detection output due to the arrival of a person can be obtained with the influence of infrared changes due to the environment removed.

Therefore, if this is waveform-shaped by a waveform-shaping circuit (36), a trigger signal that is in the - state when a human is present within the angle of view can be obtained.

Embodiment of G2 Color Imaging Apparatus Next, FIG. 6 shows another example of the apparatus of this invention, and this example is an example in the case of a color imaging apparatus.

In the case of this color imaging device, an optical color filter (42) as shown in FIG. 7, for example, is provided in front of the effective pixel area of the CCD imager (41). That is, this color filter (42) has ■1947 lines every other line.
For each pixel, a filter element R having wavelength selectivity that transmits red light and a filter element G having wavelength selectivity that transmits green light are arranged alternately for each pixel, and for the remaining one line. For every other line of pixels, a filter element B having wavelength selectivity that transmits blue light and a filter element G having wavelength selectivity that transmits green light are arranged alternately for each pixel, Further, the green light filter elements G are arranged in a line in the vertical direction.

In this case as well, it is possible to use the filter part facing the pixels in the ineffective area as an infrared light transmitting part to obtain an infrared light detection output in the same way as in the previous example, and to obtain a recording trigger signal for the VTR. To obtain the infrared light detection output, proceed as follows.

That is, in this example, some random positions on the back of the red light filter element R, which is close in wavelength to infrared light, are used as infrared light transmitting parts IR having wavelength selectivity to transmit infrared light. I'll leave it there.

The output from the CCD imager (41) is then supplied to a process circuit (43) where it undergoes predetermined signal processing.
Also, is there a possibility of signal loss due to a defect in the CCD imager itself as mentioned above? It is also performed during di.

The output of this process circuit (43) is the matrix circuit (43).
4), from which red, green and blue primary color signal outputs SR, SG and SB are obtained. Of these, the red IJi color signal SR is supplied to the switch circuit (45). on the other hand,
A switch switching signal is obtained from the timing signal forming circuit <47) based on the position ii signal from the memory (46) that stores the position of the infrared light transmitting part IR at a random position, and this causes the switching circuit (45 ) is switched to the A side when the output is from the pixel facing the red filter section R, and to the B side when the output is from the pixel facing the infrared light transmitting section TR. Therefore, the red primary color (B) is obtained from the A side output terminal of the switch circuit (45), and the infrared light detection output is obtained from the B side output terminal, and these are obtained from the sampling and hold circuits (48) and (49). ) is sampled and held.

Then, the edge and blue primary color signal outputs SG and SB from the matrix circuit (44) and the sampling hold circuit 1m
The red primary color signal output SR from (48) is connected to the encoder (
50) for example N'r SC color image F
The IA signal is supplied to the VTR (21).

Further, the infrared light detection output SIR from the sampling hold circuit (49) is supplied to the trigger signal forming circuit (51) configured as described above, from which the recording 1-trigger signal TO is obtained, and the VTR (It is supplied to 2+.

As mentioned above, red light and infrared light are close in wavelength, so even if this infrared light detection output is included as the red primary color signal output, the screen will not become unsightly. it is conceivable that.

If this is taken into account, as in the example of FIG.
50), and now NTSC color video @! In addition to obtaining the signal, only the infrared light detection output portion of the red primary color (aJF+sR) may be sampled and held by the sampling and holding circuit (52) and extracted.

In this case, the readout output of the memory (53) that records the pixel position corresponding to the infrared light transmitting part IR is supplied to the timing signal forming circuit (54), and at the time of the pixel position where the infrared light is detected. The sampling pulse is supplied to the sampling bold circuit (52).

The above description has been made by taking as an example the case where the imaging device according to the present invention is used as a surveillance camera in a surveillance system, but the infrared light detection output obtained from the CCD imager has coarse pixels, but is an infrared sensing image signal. This can also be used for image processing, for example, for camera autofocus.

Note that if the infrared light transmitting parts IR for infrared light detection are arranged not at random but as needed, it becomes possible to distribute the infrared light detection signals.

According to this invention, an optical filter is arranged in front of the CCD imager, and a part of this optical filter is used as an infrared light detection section, so that a part of the pixels of the CCD imager can be detected by infrared light. Since it is used as a light detection sensor, an imaging output and an infrared light detection output can be obtained from the imaging device.

Therefore, if the present invention is used in a surveillance system, there is an advantage that there is no need to separately provide a surveillance camera and an infrared detection section for detecting a human body.

Further, according to the present invention, since the CCD imager is common for imaging output and infrared detection output, separate (
There is no need to provide a fixed sensor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the device of the present invention, FIGS. 2 to 4 are diagrams showing an example of the configuration of an optical filter, and FIG. 5 is a block diagram of another example of a partial circuit of the example shown in FIG. 1. 6 is a block diagram of another embodiment of this invention device, FIG. 7 is an example of an optical filter not shown, FIG. 8 is a block diagram of still another embodiment of this invention device, and FIG. 9 is a block diagram of another embodiment of this invention device. 1 to 11 are block diagrams of examples of conventional monitoring systems, respectively. (21) and (41) are CCD imagers, and (22) and (42) are optical filters.

Claims (1)

[Claims] It is equipped with a CCD imager and an optical filter disposed on the front side of the imaging section of the CCD imager and having an infrared light detection section formed in a part thereof, and the imaging output from the CCD imager and the optical filter that passes through the infrared light detection section. An imaging device capable of obtaining a detection output of infrared light in incident light.