JPH1141496A - Monitor camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain such a video signal that an image of a monitor object in each monitor area has proper luminance in whatever illuminance state monitor objects in monitor areas are. SOLUTION: A monitor object discriminating means 5 supplies monitor object discrimination signals SA and SB corresponding to the monitor objects in the 1st and 2nd monitor areas to detection parts 7a and 7b in an exposure control means 6. The detection parts 7a and 7b detects only the monitor object parts in the 1st and 2nd monitor areas as to the output signals of respective image pickup elements 2 to obtain detection outputs based upon the illuminance of the monitor objects. The quantity of light transmission of dimming means 9a and 9b limiting the quantity of incident light of the image pickup elements 2 corresponding to the monitor areas are brought under feedback control according to the detection outputs of the detection parts 7a and 7b. The output signal levels of the image pickup elements 2 corresponding to the monitor objects in the monitor areas become constant independently of the illuminance state other than the monitor objects to obtain such, a video signal SV that images of the monitor objects in the respective monitor areas have proper luminance respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera for imaging, for example, a plurality of monitoring areas around a vehicle by using a single image sensor. However, the present invention also relates to a surveillance camera that obtains a video signal in which images to be monitored in the respective monitoring areas have appropriate brightness.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a surveillance camera for imaging a plurality of surveillance areas around a vehicle using a single image sensor. Examples of this type of surveillance camera include, for example,
There is a technique disclosed in JP-A-85385. FIG.
It is a block diagram explaining the technique, It is a polarizing means 101 which forms the optical path for collecting the light image on either side at one place.
And imaging means 10 for converting the collected light image into a video signal
2 and a display 106 for displaying an image based on the video signal. When forming an optical image, the left and right controllers 105a, 105b are controlled according to the electric signals obtained by the optical sensors 103a, 103b.
b controls the transmittance of the left and right transmittance variable filters 104a and 104b, and it is possible to simultaneously display images of a plurality of monitoring areas with uniform brightness on one screen.

[0003]

However, in the above-described surveillance camera, since the amount of light in each surveillance area is equalized,
Only the brightness of the image for each area is equalized,
The monitoring target is not always displayed as a clear image. In other words, if there is an area other than the monitoring target in the monitoring area, such as a high-brightness part such as the sky or the sun, having an brightness different from that of the monitoring target, an area having an exposure different from that of the monitoring target. And the image displayed on the display 106 becomes too dark or too bright. The present invention has been made in order to solve the above problems, and even if the monitoring target in each monitoring area is under any illuminance condition,
It is an object of the present invention to provide a surveillance camera capable of obtaining a video signal in which an image of a monitoring target in each monitoring area has appropriate brightness.

[0004]

According to a first aspect of the present invention, there is provided a surveillance camera, comprising: an image pickup device; optical means for forming an image of a plurality of monitoring areas on an image pickup surface of the image pickup device; In a surveillance camera having a signal processing means for obtaining a video signal by processing a video signal, a monitoring target separation means for separating the monitoring targets in a plurality of monitoring areas, and a monitoring target separation signal output from the monitoring target separation means. Control means for controlling at least the optical system or the signal processing system so that the image of the monitoring target in the plurality of monitoring areas based on the video signal has a substantially constant brightness.

According to a second aspect of the present invention, there is provided a surveillance camera according to the first aspect, wherein the control means is an exposure control means, and the exposure control means is provided for each monitoring target portion separated by the monitoring target separation means. A plurality of light control means for adjusting the brightness of images of a plurality of monitoring areas formed on the imaging surface of the image sensor; and And a drive means for driving a plurality of light control means.

According to a third aspect of the present invention, in the surveillance camera according to the second aspect of the present invention, the monitoring target-specific photometering means detects the output signal of the image sensor for each monitoring target portion separated by the monitoring target classification means. Detecting means.

According to a fourth aspect of the present invention, in the surveillance camera according to the first aspect, the control means is a gain control means, and the gain control means comprises a plurality of monitoring areas separated by the monitoring target separation means. A monitoring target photometric unit that performs photometry for each monitoring target portion, a variable gain amplifier that amplifies an output signal of the image sensor and supplies the signal processing unit, and a monitoring target photometry corresponding to each of the plurality of monitoring regions. Gain control means for controlling the gain of the variable gain amplifier based on the output signal of the means.

According to a fifth aspect of the present invention, in the surveillance camera according to the fourth aspect of the present invention, the monitoring target photometric unit detects an output signal of the variable gain amplifier for each monitoring target portion separated by the monitoring target separation unit. It comprises a plurality of detection means.

According to a sixth aspect of the present invention, the surveillance camera according to the first aspect of the present invention includes an exposure control unit and a gain control unit as the control unit, and the exposure control unit is a monitoring target separated by the monitoring target separation unit. A first monitoring target-specific photometric unit that performs photometry for each portion, a plurality of dimming units that respectively adjust the brightness of images of a plurality of monitoring regions formed on an imaging surface of an imaging signal, and a first monitoring target. A drive unit for driving a plurality of dimming units based on an output signal of the separate photometric unit, wherein the gain control unit performs photometry for each monitoring target portion of the plurality of monitoring regions separated by the monitoring target separation unit. 2, a photometric device for each monitored object, a variable gain amplifier for amplifying an output signal of the image sensor and supplying it to the signal processing device, and an output of the second photometric device for each monitored object corresponding to each of the plurality of monitoring areas. Based on the traffic light It is made of a gain control means for controlling the gain of the variable amplifier.

According to a seventh aspect of the present invention, the surveillance camera according to the first aspect of the present invention includes an exposure control unit and a gain control unit as the control unit, and the exposure control unit is a monitoring target separated by the monitoring target separation unit. A first monitoring object-based photometric unit that performs photometry for each portion, a maximum value selecting unit that selects a maximum value from the photometric results of the first monitoring object-based photometric unit, and a dimming unit that adjusts exposure to the image sensor. A drive unit for driving the dimming unit based on the output signal of the maximum value selection unit, and the gain control unit measures the light for each of the monitoring target portions of the plurality of monitoring areas separated by the monitoring target separation unit. A second monitoring subject-specific photometric unit, a variable gain amplifier that amplifies an output signal of the image sensor and supplies the amplified signal to a signal processing unit,
And gain control means for controlling the gain of the variable gain amplifier based on the output signal of the second monitoring object-specific photometric means corresponding to each of the plurality of monitoring areas.

According to an eighth aspect of the present invention, in the surveillance camera according to the seventh aspect, the light control means is an electronic shutter means for controlling a charge accumulation time of the image pickup device.

According to a ninth aspect of the present invention, in the surveillance camera according to any one of the first to eighth aspects, the monitoring target discriminating means includes a moving body detecting means for detecting a moving body in a plurality of monitoring areas; Range setting means for outputting a monitoring target classification signal corresponding to the monitoring target range including the moving object detected by the moving object detection means.

According to a tenth aspect of the present invention, in the surveillance camera according to any one of the first to eighth aspects, the surveillance target discriminating means is a target range input means for inputting a surveillance range for a plurality of monitoring areas. And decoding means for continuously outputting a monitoring target classification signal corresponding to the monitoring target range input by the target range input means.

According to an eleventh aspect of the present invention, in the surveillance camera, the surveillance target discriminating means stores a plurality of surveillance ranges respectively in a plurality of surveillance areas; A monitoring target range selecting means for selecting a required monitoring target range from the means; and a decoding means for continuously outputting a monitoring target classification signal corresponding to the monitoring target range selected by the monitoring target range selecting means. is there.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a surveillance camera according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a prism as an optical unit that forms a plurality of regions on one image sensor. The prism 1 is a prism for two directions. Note that a mirror can be used instead of the prism 1. Reference numeral 2 denotes an imaging device that performs photoelectric conversion, and for example, a CCD solid-state imaging device or the like is used.
Reference numeral 3 denotes an amplifier that amplifies an output signal of the image sensor 2.
Reference numeral 4 denotes a signal processing unit which performs signal processing on the output signal of the image sensor 2 amplified by the amplifier 3 so as to comply with a signal rule such as NTSC or PAL to obtain a video signal SV.

Reference numeral 5 denotes a monitoring target separation unit that separates monitoring targets in a monitoring area in two directions. In this case, since the monitoring area has two directions, two monitoring object classification signals SA and SB respectively corresponding to the monitoring objects in the two-way monitoring area.
Is output. Reference numeral 6 denotes monitoring target-specific exposure control means. The exposure control means 6 is a feedback system composed of detectors 7a and 7b as photometric means for each monitored object, drivers 8a and 8b, and dimming means 9a and 9b.

The detectors 7a and 7b are means for detecting the level of the output signal of the image sensor 2, and are composed of, for example, an integrator including a resistor and a capacitor. The drivers 8a and 8b are amplifiers that drive the light control means 9a and 9b at the subsequent stage based on the detection outputs of the detection units 7a and 7b. The dimmers 9a and 9b physically limit the amount of light incident on the image sensor 2, and include, for example, an iris diaphragm and a variable transmittance filter. The dimmers 9a and 9b are arranged on the incident side of the prism 1, but may be arranged between the prism 1 and the image sensor 2.

Here, when it is desired to keep a constant depth of field in a state where the depth of field is small depending on the monitored object, that is, when it is not desired to focus on an object other than the monitored object or when miniaturization is required, the transmittance is set. An iris diaphragm is used when a variable filter is used, while weather resistance of the filter is a concern.

Next, the operation of the surveillance camera shown in FIG. 1 will be described. In the monitoring target classification means 5, the monitoring targets in the monitoring areas 21a and 21b in two directions are separated.
This is shown in FIG. For example, when there is a monitoring target 22a in the area 21a, the monitoring target can be expressed by a vertical pulse signal AV and a horizontal pulse signal AH, and by taking the logical product of these two types of pulse signals, the monitoring target is obtained. The classification signal SA can be easily obtained. Similarly, for the area 21b, the monitoring target classification signal SB is obtained by ANDing the monitoring target 22b with the pulse signal BV in the vertical direction and the pulse signal BH in the horizontal direction.

The monitoring target classification means 5 can be easily constituted by various clocks and counters in the camera, though not shown.
In addition, in a surveillance camera application, the camera is often used in a fixed state, and the position to be monitored is inevitably determined. Therefore, there is no particular problem even if a predetermined area is determined in advance. The monitoring target classification signals SA and SB obtained by the monitoring target classification unit 5 are supplied to the detection units 7a and 7b in the monitoring target classification control unit 6, respectively.

First, the operation of exposure control for the area 21a will be described. The output signal of the image sensor 2 is supplied to the detection unit 7a together with the above-described monitored target separation signal SA. The detector 7a detects only a portion of the output signal of the image sensor 2 corresponding to the monitoring target 22a based on the monitoring target separated signal SA, and does not detect other portions but outputs the immediately preceding detection output. Is held. Therefore, the detection output of the detection unit 7a is based on the illuminance of the monitoring target 22a. Then, the light control means 9a is driven by the driver 8a based on the detection output. The exposure control unit 6 is a feedback system including a detection unit 7a, a driver 8a, and a dimming unit 9a. Therefore, the dimming unit is controlled so that the level of the output signal of the image sensor 2 corresponding to the monitoring target 22a becomes a constant value. In 9a, the light amount in the monitoring area 21a is limited.

Next, the operation of exposure control for the area 21b will be described. Similarly, on the side of the area 21b, the detection unit 7b includes the monitoring target discrimination signal SB and the image sensor 2
Are supplied. In the detection unit 7b, based on the monitored target separated signal SB, only the part corresponding to the monitored target 22b in the output signal of the image sensor 2 is detected. Is held. Therefore, the detection output of the detection unit 7b is based on the illuminance of the monitoring target 22b. The light control means 9b is driven by the driver 8b based on the detection output, and controls the light control means 9b so that the level of the output signal of the image sensor 2 corresponding to the monitoring target 22b becomes a constant value.
Thus, the light amount in the monitoring area 21b is limited.

As described above, according to the surveillance camera shown in FIG. 1, the exposure control means 6 is independent for each monitoring area, and based on the illuminance of the monitoring target in each monitoring area, the image sensor 2
, The level of the output signal of the image sensor 2 corresponding to the monitoring target in each monitoring region becomes a constant value without being affected by the illuminance situation other than the monitoring target, and It is possible to obtain a video signal SV in which each of the images to be monitored has appropriate brightness.

Embodiment 2 FIG. FIG. 3 shows a configuration of a surveillance camera according to Embodiment 2 of the present invention. In FIG. 3, parts corresponding to those in FIG.
The detailed description is omitted. Although the surveillance camera shown in FIG. 1 is effective when the position to be monitored in each monitoring area is fixed, the surveillance camera shown in FIG. 3 is applicable to an object in which the position to be monitored moves within the monitoring area. It is effective.

In the figure, reference numeral 31 denotes a moving body detecting means for detecting a moving body as a monitoring target in a monitoring area in two directions. For example, a difference between frames of the video signal SV is used as a detection output of the moving body. . 32 sets a range for each of the moving objects in each monitoring area based on the detection output of the moving object in each monitoring area of the moving object detecting means 31, and separates two systems of monitoring targets corresponding to the respective ranges. This is a target range setting unit that outputs the signals SA and SB, and is configured by a simple logic circuit. The moving object detecting means 31 and the target range setting means 32 constitute the monitoring target separating means 5. Other configurations of the surveillance camera shown in FIG. 3 are the same as those of the surveillance camera shown in FIG.

Next, the operation of the surveillance camera shown in FIG. 3 will be described. Moving object detecting means 31 and target range setting means 3
In 2, a moving object to be monitored in each monitoring area is detected, and a range is set for the moving object. FIG. 4 shows this state. That is, in the moving object detecting means 31, for example, if a person moves within the area 41a, the difference between frames of the video signal SV is only the outline 42 of the moving person.
In this case, it is possible to detect a moving object in the monitoring area 41a.

Similarly, when the vehicle moves within the area 41b, the difference between the frames of the video signal SV is only the outline 43 of the vehicle. Detection becomes possible. Note that the difference between the frames of the video signal SV is substantially zero because the portion other than the moving body is stationary.

The detection output of the moving object outputted from the moving object detecting means 31, that is, the difference between the frames of the video signal SV has a certain value or more at the outline of the moving object. for that reason,
In the target range setting means 32, it is easy to set a monitoring target range for each moving object (monitoring target) in each monitoring area. For example, in both the vertical and horizontal directions, a portion having a value equal to or greater than a certain value may be cut out by a straight line.
That is, as shown in FIG. 4, in the target range setting means 32, the range 44 is set as the monitoring target range for the moving body 42 in the area 41a, while the moving body 4 in the area 41b is set.
The range 45 is set as the monitoring target range for 3 and the monitoring target classification signals SA and SB are obtained by the same method as shown in FIG. Other operations of the surveillance camera shown in FIG. 3 are the same as those of the surveillance camera shown in FIG.

As described above, according to the monitoring camera shown in FIG. 3, the range of the moving object (monitoring target) in each monitoring area can be set as the monitoring target range, and the monitoring target classification signals SA and SB can be obtained. The level of the output signal of the image sensor 2 corresponding to the moving object in each monitoring area becomes a constant value, and the video signal SV in which the image of the moving object in each monitoring area has appropriate brightness can be obtained.

Embodiment 3 FIG. 5 shows a configuration of a surveillance camera according to Embodiment 3 of the present invention. In FIG. 5, parts corresponding to those in FIG.
The detailed description is omitted. Although the surveillance camera shown in FIG. 1 is effective when the position to be monitored in each surveillance area is fixed, the surveillance camera shown in FIG. 5 changes the installation location or changes the angle of view. It is effective when applied when a change such as occurs.

In the figure, reference numeral 51 denotes a target range input means for inputting a monitoring target range in a monitoring area in two directions, and comprises a volume (variable resistor), a switch and the like. Reference numeral 52 denotes a target range storage unit that stores information on the monitoring target range input by the target range input unit 51, and is configured by a semiconductor memory or the like. Reference numeral 53 denotes a decoder that generates monitoring target classification signals SA and SB corresponding to the monitoring target range in each monitoring region from information on the monitoring target range in each monitoring region stored in the target range storage unit 52. Yes, and can be realized with a simple logic circuit.
The target range input unit 51, the target range storage unit 52, and the decoder 53 constitute the monitoring target classification unit 5. Other configurations of the surveillance camera shown in FIG.
This is the same as the surveillance camera shown in FIG.

Next, the operation of the surveillance camera shown in FIG. 5 will be described. The monitoring target range is input by the user by the target range input unit 51 for each of the monitoring areas in two directions. The input information of the monitoring target range is stored in the target range storage means 52, read out from the target range storage means 52 as needed, and supplied to the subsequent decoder 53. Therefore, the monitoring target classification signals SA and SB corresponding to the monitoring target ranges of the respective monitoring regions input by the target range input means 51 are continuously output from the decoder 53. Other operations of the surveillance camera shown in FIG.
This is the same as the surveillance camera shown in FIG.

As described above, according to the surveillance camera shown in FIG. 5, when the range to be monitored in each monitoring area is input by the target range input means 51, the monitoring target of each input monitoring area is transmitted from the decoder 53. The monitoring target classification signals SA and SB corresponding to the respective ranges continue to be output. Therefore, the level of the output signal of the image sensor 2 corresponding to the input monitoring target range of each monitoring area becomes a constant value, and the input image signal of the monitoring target range of each monitoring area has an appropriate brightness. SV can be obtained.

In the above description, the target range storage means 52 stores the information of one monitoring target range inputted by the target range input means 51. Information on a plurality of monitoring target ranges input by the means 51 may be stored, and information on an arbitrary monitoring target range may be read out of the information and supplied to the decoder 53. In addition, information on a plurality of monitoring target ranges may be preset in the target range storage unit 52, and information on an arbitrary monitoring target range may be read out of the information and supplied to the decoder 53. With this configuration, the user does not need to input the monitoring target range from the target range input unit 51 every time the monitoring target range is changed, and the convenience is further improved.

Embodiment 4 FIG. FIG. 6 shows a configuration of a surveillance camera according to Embodiment 4 of the present invention. In FIG. 6, parts corresponding to those in FIG.
The detailed description is omitted. In the figure, reference numeral 61 denotes a monitoring target-based gain control means. The gain control means 61 is a feedback system composed of detectors 62a and 62b as monitoring target photometric means, drivers 63a and 63b, monitoring area switching means 64, and a variable gain amplifier 65.

The variable gain amplifier 65 is arranged between the image pickup device 2 and the signal processing section 4 and amplifies an output signal of the image pickup signal 2 and supplies the output signal to the signal processing section 4. The detectors 62a and 62b are means for detecting the level of the output signal of the variable gain amplifier 65, and include, for example, an integrator including a resistor and a capacitor. Driver 63
Reference numerals a and 63b denote amplifiers that drive the variable gain amplifier 65 based on the detection outputs of the detection units 62a and 62b. The monitoring area switching means 64 is for selectively taking out the drive signals from the drivers 63a and 63b and supplying them to the variable gain amplifier 65.

Reference numeral 5A denotes a monitoring target classification unit corresponding to the monitoring target classification unit 5 in the monitoring camera of FIG.
The system outputs two types of monitoring target classification signals SA and SB respectively corresponding to the monitoring targets in the monitoring area in the direction, and the output signal of the image sensor 2 corresponds to either side of the monitoring area in the two directions. It outputs a monitoring area discrimination signal SC indicating whether there is any. The monitoring area determination signal SC is supplied to the monitoring area switching means 64 as a switching control signal. When the output signal of the imaging device 2 corresponds to the monitoring region 21a side (see FIG. 2), the monitoring region switching means 64 is switched to take out a driving signal from the driver 63a. When the signal corresponds to the monitoring area 21b (see FIG. 2), the driver 63
It is switched to take out the drive signal from b. Other configurations of the surveillance camera shown in FIG. 6 are the same as those of the surveillance camera shown in FIG.

Next, the operation of the monitoring camera shown in FIG. 6 will be described. In the monitoring target classification unit 5A, the monitoring targets in the two-directional monitoring areas 21a and 21b are classified by the same method as that of the monitoring target classification unit 5 of the monitoring camera in FIG. Then, this monitoring target separation means 5A
Are supplied to the detectors 62a and 62b in the monitor-specific gain control means 61, respectively.

First, the operation of gain control for the area 21a will be described. The output signal of the variable gain amplifier 65 is supplied to the detector 62a together with the above-described monitored target classification signal SA. The detector 62a detects only a portion of the output signal of the variable gain amplifier 65 corresponding to the monitoring target 22a based on the monitoring target separated signal SA, and does not detect other portions, but detects the immediately preceding detection. Output is retained. Therefore, the detection output of the detection unit 7a is
This is based on the illuminance of a.

The monitoring area switching means 64 is supplied with the monitoring area discrimination signal SC from the monitoring object discriminating means 5A. When the output signal of the image sensor 2 corresponds to the monitoring area 21a, the driver 63a The driving signal from is extracted. Therefore, the variable gain amplifier 65 is driven by the driver 63a based on the detection output of the detection unit 62a. Here, since the detection unit 62a, the driver 63a, and the variable gain amplifier 65 constitute a feedback system, the variable gain amplifier is controlled so that the level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target 22a becomes a constant value. A gain of 65 is controlled.

Next, the operation of gain control for the region 21b (see FIG. 2) will be described. Similarly, on the side of the area 21b, the output signal of the variable gain amplifier 65 is supplied to the detector 62b together with the monitoring target classification signal SB. The detector 62b detects only a portion of the output signal of the variable gain amplifier 65 corresponding to the monitoring target 22b based on the monitoring target separated signal SB, and does not detect other portions, but detects the immediately preceding detection. Output is retained. Therefore, the detection output of the detection unit 62b is based on the illuminance of the monitoring target 22b.

The monitoring area switching means 64 is supplied with the monitoring area discrimination signal SC from the monitoring object discriminating means 5A. When the output signal of the image sensor 2 corresponds to the monitoring area 21b, the driver 63b The driving signal from is extracted. Therefore, the variable gain amplifier 65 is driven by the driver 63b based on the detection output of the detection unit 62b, and is connected to the variable gain amplifier 6 corresponding to the monitoring target 22b.
The gain of the variable gain amplifier 65 is controlled so that the level of the output signal of No. 5 becomes a constant value.

As described above, according to the surveillance camera shown in FIG. 6, the gain control means 61 is independent for each monitoring area, and the gain of the variable gain amplifier 65 is controlled based on the illuminance of the monitoring target in each monitoring area. , The level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target in each monitoring region becomes a constant value without being affected by the illuminance condition other than the monitoring target, and the monitoring target in each monitoring region is It is possible to obtain a video signal SV in which each image has appropriate brightness. Also, as in the surveillance camera shown in FIG.
There is also an effect that the size can be significantly reduced as compared with the case of using. It is also possible to adopt a configuration in which the detection outputs of the detection units 62a and 62b are selectively extracted by the monitoring area switching means 64 and the extracted detection outputs are supplied to a single driver that drives the variable gain amplifier 65. As a result, only one driver is required.

Embodiment 5 FIG. FIG. 7 shows a configuration of a surveillance camera according to Embodiment 5 of the present invention. 7, parts corresponding to those in FIGS. 1 and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. The surveillance camera shown in FIG. 7 has a monitoring object-specific exposure control means 6 in the surveillance camera shown in FIG. 1 and a surveillance camera-specific gain control means 61 in the surveillance camera shown in FIG. In this case, the monitoring target classification signal SA from the monitoring target classification unit 5a
Is supplied to the detector 62a of the gain controller 61,
It is also supplied to the detector 7a of the exposure controller 6. Similarly,
The monitoring target classification signal SB from the monitoring target classification unit 5 a is supplied to the detection unit 62 b of the gain control unit 61 and also to the detection unit 7 b of the exposure control unit 6. Other configurations of the surveillance camera shown in FIG. 7 are the same as those of the surveillance camera shown in FIGS. 1 and 6.

Next, the operation of the surveillance camera shown in FIG. 7 will be described. When the object to be monitored is high illuminance, a signal of a sufficient level can be obtained as an output signal of the image sensor 2 only by the control of the exposure control means 6, and the gain control means 61 operates as a gain control of the variable gain amplifier 65. Is not performed, and the gain of the variable gain amplifier 65 remains constant. That is, it is equal to the control situation of the monitoring camera shown in FIG. On the other hand, when the monitoring target is at low illuminance, the light control means 9 in the exposure control means 6
The transmittances of a and 9b become maximum, and the subsequent control is left to the gain control means 61. That is, it becomes equal to the control situation of the monitoring camera shown in FIG.

As described above, according to the surveillance camera shown in FIG. 7, even if the illuminance change of a wide range of monitored objects from high illuminance to low illuminance, the variable gain amplifier 65 corresponding to the monitored object in each monitored area can be used. The level of the output signal becomes a sufficiently constant value, and it is possible to obtain the video signal SV in which the images to be monitored in each monitoring area have appropriate brightness.

Embodiment 6 FIG. FIG. 8 is a block diagram showing a configuration of a surveillance camera according to Embodiment 6 of the present invention. 8, parts corresponding to those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, 9
Is a single dimming unit that physically limits the amount of light incident on the image sensor 2, and includes, for example, an iris diaphragm and a transmittance variable filter. The light control means 9 is arranged between the prism 1 and the image sensor 2.

Reference numerals 81a and 81b denote detectors for detecting the level of the output signal of the image sensor 2, respectively. 82
Is a maximum value selecting means for selectively outputting the larger one of the detection outputs of the detectors 81a and 81b. Reference numeral 83 denotes a driver that controls the amount of light transmitted by the dimmer 9 based on the detection output selected by the maximum value selector 82. In this case, the light transmission amount of the light control means 9 is controlled to decrease as the detection output increases, and the detection units 81a and 81b, the maximum value selection means 82, the driver 83 and the light control means 9 constitute a feedback system. doing. Other configurations of the surveillance camera shown in FIG. 8 are the same as those of the surveillance camera shown in FIG.

Next, the operation of the monitoring camera shown in FIG. 8 will be described. The monitoring target separation signals SA and SB for separating the monitoring targets in the two-way monitoring areas 21a and 21b (see FIG. 2) obtained from the monitoring target separation unit 5A are supplied to the detection units 62a and 62b of the gain control unit 61, respectively. At the same time, it is supplied to the detectors 81a and 81b. Detection means 81
In a and 81b, only a portion of the output signal of the image sensor 2 corresponding to a monitoring target in each of the monitoring areas 21a and 21b is detected. The maximum value selecting means 82 outputs the larger one of the detection outputs of the detectors 81a and 81b. Based on the output signal of the maximum value selecting means 82,
The driver 83 controls the light transmission amount of the light control means 9.

Here, when the illuminance is high and the detection output of the detection unit 81a is larger than the detection output of the detection unit 81b, for example, the detection output of the detection unit 81a is output from the maximum value selection unit 83. Dimming means 9 based on detection output
Is controlled. Therefore, the level of the output signal of the image sensor 2 corresponding to the monitoring target 22a in the monitoring area 21a becomes a sufficiently constant value due to the feedback control, but the level of the output signal of the imaging element corresponding to the monitoring target 22b in the monitoring area 21b. Becomes insufficient. However, the insufficient level of the output signal of the image sensor 2 corresponding to the monitoring target 22b in the monitoring area 21b is corrected by the gain control unit 61 in the subsequent stage.

That is, the monitoring target 22 in the monitoring area 21a
a, the level of the output signal of the image sensor 2 corresponding to a becomes a sufficiently constant value.
5, the gain of the variable gain amplifier 65 remains constant. On the other hand, the monitoring area 21b
Since the level of the output signal of the image sensor 2 corresponding to the monitoring target 22b is insufficient, the gain control means 61 performs the gain control operation of the variable gain amplifier 65. As a result, the level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target in each monitoring region becomes a sufficiently constant value, and the video signal SV in which the monitoring target image in each monitoring region has appropriate brightness is obtained. be able to.

Conversely, when the detection output of the detection unit 81b is larger than the detection output of the detection unit 81a,
Image sensor 2 corresponding to monitoring target 22a in monitoring area 21a
Although the level of the output signal becomes insufficient, it is similarly corrected by the gain control means 61 at the subsequent stage. The detection unit 81
When the detection output of the detection area b is equal to the detection output of the detection unit 81a, the monitoring targets 22a and 22b of the monitoring areas 21a and 21b are used.
The level of the output signal of the image sensor 2A corresponding to the above is both sufficiently constant. Further, at the time of low illuminance, the transmittance of the light control means 9 becomes maximum, and the subsequent control is left to the gain control means 61, which is equal to the control situation of the surveillance camera shown in FIG.

As described above, according to the surveillance camera shown in FIG. 8, similarly to the surveillance camera shown in FIG. The level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target becomes a sufficiently constant value, and it is possible to obtain the video signal SV in which the image of the moving object in each monitoring area has appropriate brightness. Further, the surveillance camera shown in FIG. 7 requires two dimming means 9a and 9b. However, according to the surveillance camera shown in FIG. be able to.

Embodiment 7 FIG. FIG. 9 is a block diagram showing a configuration of a surveillance camera according to Embodiment 7 of the present invention. In the surveillance camera shown in FIG. 9, the charge accumulation time of the image sensor is controlled without using dimming means such as an iris diaphragm and a transmittance variable filter to control the level of the output signal of the image sensor. It was done. 9, parts corresponding to those in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the figure, reference numeral 2A denotes an image sensor corresponding to the image sensor 2 of the surveillance camera shown in FIG. The image pickup device 2A has an electronic shutter function that can arbitrarily set the charge accumulation time. Reference numeral 91 denotes an accumulation time setting unit that sets the charge accumulation time of the image sensor 2A based on the detection output selected by the maximum value selection unit 82. In this case, the charge accumulation time of the image pickup device 2A is set shorter as the detection output increases, and therefore, the detection units 81a and 81b, the maximum value selection unit 82, the charge accumulation time setting unit 91, and the image pickup device 2A
Constitutes a feedback system. Incidentally, since charges are accumulated in the image sensor 2A in proportion to the light intensity and the accumulation time, controlling the electric charge accumulation time has the same effect as controlling the amount of incident light on the image sensor 2A by the dimming means. Is obtained. Other configurations of the surveillance camera shown in FIG. 9 are the same as those of the surveillance camera shown in FIG.

Next, the operation of the surveillance camera shown in FIG. 9 will be described. The monitoring target separation signals SA and SB for separating the monitoring targets in the two-way monitoring areas 21a and 21b (see FIG. 2) obtained from the monitoring target separation unit 5A are supplied to the detection units 62a and 62b of the gain control unit 61, respectively. At the same time, it is supplied to the detectors 81a and 81b. Detection means 81
In a and 81b, only a portion of the output signal of the image sensor 2A corresponding to the monitoring target in the respective monitoring areas 21a and 21b is detected. The maximum value selecting means 82 outputs the larger one of the detection outputs of the detectors 81a and 81b. Based on the output signal of the maximum value selecting means 82, the charge accumulation time of the image sensor 2A is set by the accumulation time setting unit 91.

Here, when the illuminance is high, for example, when the detection output of the detection unit 81a is larger than the detection output of the detection unit 81b, the detection output of the detection unit 81a is output from the maximum value selection unit 82. Depending on the detection output, the image sensor 2
The charge accumulation time of A is set. Therefore, the level of the output signal of the imaging element 2A corresponding to the monitoring target 22a in the monitoring area 21a becomes a sufficiently constant value by the feedback control, but the level of the output signal of the imaging element 2A corresponding to the monitoring target 22b in the monitoring area 21b is maintained. The level will be insufficient. However, the insufficient level of the output signal of the image sensor 2 corresponding to the monitoring target 22b in the monitoring area 21b is corrected by the gain control unit 61 in the subsequent stage.

That is, the monitoring target 22 in the monitoring area 21a
Since the level of the output signal of the image sensor 2A corresponding to a becomes a sufficiently constant value, the gain control means 61 does not perform the operation of controlling the gain of the variable gain amplifier 65, and the gain of the variable gain amplifier 65 remains constant. Become. On the other hand, the monitoring area 21
Since the level of the output signal of the image sensor 2A corresponding to the monitoring target 22b of b is insufficient, the gain control means 61 controls the gain of the variable gain amplifier 65. As a result, the level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target in each monitoring region becomes a sufficiently constant value, and the video signal SV in which the monitoring target image in each monitoring region has appropriate brightness is obtained. be able to.

Conversely, when the detection output of the detection unit 81b is larger than the detection output of the detection unit 81a,
Image sensor 2 corresponding to monitoring target 22a in monitoring area 21a
Although the level of the output signal of A becomes insufficient, it is similarly corrected by the gain control means 61 in the subsequent stage. The detection unit 8
When the detection output of the detection unit 1b is equal to the detection output of the detection unit 81a, the monitoring targets 22a and 22b in the monitoring areas 21a and 21b are used.
The level of the output signal of the image sensor 2A corresponding to the above is both sufficiently constant. Further, at the time of low illuminance, the charge accumulation time of the image sensor 2A becomes maximum, and the subsequent control is left to the gain control means 61, which is equal to the control situation of the monitoring camera shown in FIG.

As described above, according to the surveillance camera shown in FIG. 9, similarly to the surveillance camera shown in FIG. The level of the output signal of the variable gain amplifier 65 corresponding to the monitoring target becomes a sufficiently constant value, and the video signal SV in which the monitoring target image in each monitoring area has an appropriate brightness.
Can be obtained. Further, the surveillance camera shown in FIG. 8 requires the dimming means 9, but according to the surveillance camera shown in FIG. 9, the dimming means can be omitted, and the cost is lower than that of the surveillance camera shown in FIG. In addition, downsizing can be achieved.

Embodiment 8 FIG. Note that, in each of the above-described embodiments, a case has been described in which a monitoring area is two-way. However, the present invention can be similarly applied to a case where there are three or more monitoring areas. In this case, the number of the detectors constituting the monitoring target-specific photometry means is required by the number of the monitoring areas.

[0062]

According to the first aspect of the present invention, the video signal obtained by processing the output signal of the image sensor independently for each monitoring area based on the illuminance of the monitoring target in each monitoring area. At least the optical system or the signal processing system is controlled so that the images of the monitoring objects in the plurality of monitoring areas have a substantially constant brightness, and each monitoring is performed without being affected by the illuminance situation other than the monitoring objects. It is possible to obtain a video signal in which the images to be monitored in the area have appropriate brightness.

According to a second aspect of the present invention, in the first aspect of the present invention, based on the illuminance of a monitoring target in each monitoring area,
Independently for each monitoring area, the exposure to the image sensor is adjusted using the light control means, and the image of the monitoring target in each monitoring area is not affected by the illuminance condition other than the monitoring target. Video signals having appropriate brightness can be obtained.

According to a third aspect of the present invention, in the second aspect of the present invention, the monitoring target-specific photometry means comprises a plurality of detection means for detecting an output signal of the image sensor for each monitoring target portion. Photometry can be favorably performed for each monitoring target portion of the area.

According to a fourth aspect of the present invention, in the first aspect of the present invention, based on the illuminance of a monitoring target in each monitoring area,
Independently for each monitoring area, it controls the gain of the variable gain amplifier that amplifies the output signal of the image sensor and supplies it to the signal processing means. It is possible to obtain a video signal in which the images to be monitored in the monitoring area have appropriate brightness. Also,
The size can be significantly reduced as compared with the case using the light control means.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the photometric means for each monitoring target comprises a plurality of detecting means for detecting the output signal of the variable gain amplifier for each monitoring target portion. Photometry can be performed satisfactorily for each monitoring target portion of the monitoring area.

According to the invention of claim 6, in the invention of claim 1, based on the illuminance of the monitoring target in each monitoring area,
Independently for each monitoring area, the exposure to the image sensor is adjusted by using the dimmer, and the gain of the variable gain amplifier that amplifies the output signal of the image sensor and supplies the amplified signal to the signal processor is controlled. Yes, the level of the output signal of the variable gain amplifier corresponding to the monitoring target in each monitoring area becomes a sufficiently constant value even when the illuminance changes in a wide range of monitoring targets from high illuminance to low illuminance. It is possible to obtain a video signal SV in which each of the images to be monitored has appropriate brightness.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the exposure to the image sensor is adjusted using the light control means based on the maximum value of the illuminance of the monitoring target in each monitoring area. Based on the illuminance of the monitoring target in each monitoring area,
Independently for each monitoring area, it controls the gain of the variable gain amplifier that amplifies the output signal of the image sensor and supplies it to the signal processing means. On the other hand, the level of the output signal of the variable gain amplifier corresponding to the monitoring target in each monitoring region becomes a sufficiently constant value, and the video signal SV in which the monitoring target image in each monitoring region has appropriate brightness is obtained. be able to. Also, the exposure to the image sensor is not independently adjusted for each monitoring area, but can be realized by one dimming unit, and the cost and size can be reduced.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the dimming means is realized by an electronic shutter means for controlling a charge accumulation time of the image pickup device, such as an iris diaphragm or a transmittance variable filter. This eliminates the need for dimming means for limiting the amount of incident light on the image pickup device, and can further reduce the cost and size.

According to the ninth aspect of the present invention, in any one of the first to eighth aspects, the range of the moving object (monitoring target) in each monitoring area can be set as a monitoring target range, and a monitoring target classification signal is obtained. Thus, it is possible to obtain a video signal in which an image of a moving object as a monitoring target in each monitoring area has appropriate brightness.

According to the invention of claim 10, claims 1 to 8
In any one of the inventions, a target range input means for inputting a monitoring target range for a plurality of monitoring areas, and a monitoring target classification signal corresponding to the monitoring target range input by the target range input means are output. And a video signal in which images in the monitoring target range of each monitoring region input by the target range inputting device have appropriate brightness.

According to the invention of claim 11, claims 1 to 8
In any one of the inventions, a target range storage means for storing a plurality of monitoring target ranges for each of a plurality of monitoring areas, and a target range selection for selecting a required monitoring target range from the target range storage means Means, and decoding means for continuously outputting a monitoring target classification signal corresponding to the monitoring target range selected by the target range selecting means, and the monitoring target of each monitoring area selected by the target range selecting means. A video signal in which the images in the range have appropriate brightness can be obtained. The user does not have to input the monitoring target range every time the monitoring target range is changed, and the convenience is further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a surveillance camera according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating a monitoring target classification unit.

FIG. 3 is a block diagram illustrating a configuration of a surveillance camera according to Embodiment 2 of the present invention.

FIG. 4 is a diagram for explaining a moving object detection unit and a target range setting unit.

FIG. 5 is a block diagram showing a configuration of a surveillance camera according to Embodiment 3 of the present invention.

FIG. 6 is a block diagram showing a configuration of a surveillance camera according to Embodiment 4 of the present invention.

FIG. 7 is a block diagram showing a configuration of a surveillance camera according to Embodiment 5 of the present invention.

FIG. 8 is a block diagram showing a configuration of a surveillance camera according to Embodiment 6 of the present invention.

FIG. 9 is a block diagram showing a configuration of a surveillance camera according to Embodiment 7 of the present invention.

FIG. 10 is a block diagram illustrating a configuration of a monitoring camera as a conventional example.

[Explanation of symbols]

1 prism, 2, 2A image sensor, 3 amplifier, 4
Signal processing unit, 5, 5A monitoring target classification means, 6 monitoring target-specific exposure control means, 7a, 7b, 62a, 62b, 81
a, 81b detector, 8a, 8b, 63a, 63b driver, 9, 9a, 9b dimming means, 21a, 21b,
41a, 41b monitoring area, 22a, 22b monitoring target, 31 moving object detecting unit, 32 target range setting means, 4
2, 43 contours, 51 target range input means, 52 target range storage means, 53 decoder, 64 monitoring area switching means, 65 variable gain amplifier, 82 maximum value selection means, 9
1 accumulation time setting section.

Claims (11)

[Claims] 1. An image pickup device comprising: an image pickup device; optical means for forming images of a plurality of monitoring areas on an image pickup surface of the image pickup device; and signal processing means for processing an output signal of the image pickup device to obtain a video signal. In the surveillance camera, a monitoring target separation unit that separates the monitoring targets in the plurality of monitoring regions, and a monitoring target separation signal output from the monitoring target separation unit. And a control means for controlling at least an optical system or a signal processing system so that the image to be monitored has a substantially constant brightness. 2. The monitoring device according to claim 1, wherein the control unit is an exposure control unit, and the exposure control unit is a monitoring target-specific photometry unit that performs photometry for each monitoring target portion separated by the monitoring target separation unit; Driving the plurality of dimming units based on output signals of the plurality of dimming units respectively adjusting the brightness of the images of the plurality of monitoring regions formed on the imaging surface and the monitoring target-specific photometric units. The surveillance camera according to claim 1, comprising a drive unit. 3. The monitoring target-specific photometering means comprises a plurality of detecting means for detecting an output signal of the image sensor for each monitoring target portion separated by the monitoring target separating means. A surveillance camera according to item 1. 4. The monitoring target photometering means, wherein the control means is a gain control means, wherein the gain control means performs photometry for each monitoring target portion of the plurality of monitoring areas separated by the monitoring target separation means. A variable gain amplifier that amplifies an output signal of the image sensor and supplies the amplified signal to the signal processing unit; and a gain variable amplifier corresponding to each of the plurality of monitoring areas, based on an output signal of the monitoring target-specific photometry unit. The surveillance camera according to claim 1, further comprising gain control means for controlling a gain of the variable amplifier. 5. The monitoring target-specific photometering means comprises a plurality of detection means for detecting an output signal of the variable gain amplifier for each monitoring target portion classified by the monitoring target classification means. The surveillance camera according to 4. 6. An exposure control means and a gain control means as said control means, wherein said exposure control means is a first monitoring object-specific photometry means for performing photometry for each monitoring target portion separated by said monitoring target separation means. And a plurality of dimming units that respectively adjust the brightness of the images of the plurality of monitoring regions formed on the imaging surface of the imaging element, based on an output signal of the first monitoring target-specific photometry unit, A drive unit for driving the plurality of dimming units, wherein the gain control unit measures light for each monitoring target portion of the plurality of monitoring regions separated by the monitoring target separation unit.
Monitoring target photometric means, and a variable gain amplifier that amplifies the output signal of the image sensor and supplies the amplified signal to the signal processing means,
2. A gain control means for controlling a gain of the variable gain amplifier based on an output signal of the second monitoring target-specific photometric means corresponding to each of the plurality of monitoring areas. A surveillance camera according to item 1. 7. A first metering means for each monitoring target, which comprises an exposure control means and a gain control means as said control means, and said exposure control means measures light for each monitoring target portion separated by said monitoring target separation means. A maximum value selecting unit that selects a maximum value from the photometric results of the first monitoring target-specific photometric unit; a light control unit that adjusts exposure to the image sensor; and an output signal of the maximum value selecting unit. A drive unit for driving the dimming unit, wherein the gain control unit measures light for each monitoring target portion of the plurality of monitoring areas separated by the monitoring target separation unit.
Monitoring target photometric means, and a variable gain amplifier that amplifies the output signal of the image sensor and supplies the amplified signal to the signal processing means,
2. A gain control means for controlling a gain of the variable gain amplifier based on an output signal of the second monitoring target-specific photometric means corresponding to each of the plurality of monitoring areas. A surveillance camera according to item 1. 8. The surveillance camera according to claim 7, wherein said light control means is an electronic shutter means for controlling a charge accumulation time of said image sensor. 9. The monitoring target discriminating means includes: a moving body detection means for detecting a moving body in the plurality of monitoring areas; and a monitoring target range including the moving body detected by the moving body detection means. The surveillance camera according to any one of claims 1 to 8, further comprising a range setting unit that outputs the monitoring target classification signal. 10. The monitoring target discriminating means, a target range inputting means for inputting a monitoring target range for the plurality of monitoring areas, and the monitoring target corresponding to the monitoring target range inputted by the target range inputting means. The surveillance camera according to any one of claims 1 to 8, further comprising decoding means for continuously outputting the target classification signal. 11. The monitoring target classification unit includes: a target range storage unit that stores a plurality of monitoring target ranges for each of the plurality of monitoring regions; and a monitoring target range required from the target range storage unit. A monitoring target range selecting means for selecting the monitoring target range, and decoding means for continuously outputting the monitoring target classification signal corresponding to the monitoring target range selected by the monitoring target range selecting means. 9. The surveillance camera according to any one of 8.