JP2002300467A - Monitor camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely control the lighting and lighting-out of an auxiliary illuminating device 3 for compensating the shortage of illumination, according to the luminance of a monitor area by correctly determining the brightness of the monitor area. SOLUTION: This system is provided with an auxiliary illuminating device 3; an illumination control unit 10 for controlling the lighting and lighting-out of the auxiliary illuminating device 3; an electronic shutter control unit 5 for outputting the number of shutter pulses, for controlling the shutter speed of an electronic shutter function for controlling the charge storing time of a fixed imaging element 4 arranged in the imaging device 1, based on a video signal obtained by the imaging of the imaging device 1; an automatic gain control unit 6 for controlling the gain by changing a gain control voltage value, and for outputting the gain control voltage value; and a determining part 7 for deciding whether or not the auxiliary illuminating device 3 should be lighted or lighted out, by determining the brightness of the monitor area, based on the number of shutter pulses and the gain control voltage value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera system for processing an image signal obtained by imaging a surveillance area by an imaging device having a solid-state imaging device and detecting an intruder or monitoring an article. More particularly, the present invention relates to a surveillance camera system that includes an auxiliary lighting device that compensates for insufficient illuminance in a monitoring area, and controls turning on and off of the auxiliary lighting device according to the illuminance in the monitoring area.

[0002]

2. Description of the Related Art Conventionally, there are various environments in which this type of surveillance camera system is installed. The surroundings of an imaging device are brightened by external light or indoor lighting during the day, but darkened at night. The level of a video signal obtained by an imaging device is low, and it is generally difficult to detect an intruder or monitor an article. Therefore, there is an auxiliary lighting device provided to compensate for the lack of illuminance in the monitoring area.
Always turning on the auxiliary lighting device without turning on and off the control device consumes wasteful power and shortens the life of the auxiliary lighting device. The on / off of the auxiliary lighting device is controlled using the output of an optical sensor such as an illuminometer and Cds. Alternatively, when the luminance level of the video signal obtained by the imaging device is equal to or lower than the reference level, the auxiliary lighting device is controlled to be turned on.

[0003] By the way, an image pickup apparatus for picking up an image of a monitoring area for detecting an intruder in the monitoring area, monitoring an article, or the like mainly includes a CCD (Charge Coupled Device) or a CMOS.
(Complementary Metal Oxided Semiconductor) and other imaging devices having a solid-state imaging device are used.

[0004]

However, the conventional surveillance camera system has a luminometer, Cds, which is attached separately from the image pickup device to control turning on / off of the auxiliary lighting device.
When the output of an optical sensor is used, there is a problem that the cost increases, and when the brightness level of a video signal obtained by the imaging device is used, the charge of a solid-state imaging device provided in the imaging device is increased. In those having an electronic shutter function for controlling the accumulation time, or those having an automatic gain control unit for outputting the video signal at a constant level,
Since the average brightness level of the output video signal is kept constant, the brightness level does not always accurately reflect the brightness of the monitoring area, and the accuracy of determining the brightness of the monitoring area is not good. It is not possible to optimally control the turning on / off of the auxiliary lighting device according to the illuminance of the monitoring area, consume wasteful power, and always maintain the auxiliary lighting device in the lighting state when the monitoring area is dark. This makes it impossible to reliably compensate for the lack of illuminance in the monitoring area, making it difficult to detect an intruder or monitor an article.

[0005] Therefore, in the present invention, in order to solve the above-mentioned problems, a video signal obtained by capturing an image of a monitoring area by an imaging device (for example, a CCD camera) having a solid-state imaging device is processed and intruded. When detecting a person or monitoring an article, the brightness of the monitoring area can be correctly determined, and the turning on and off of the auxiliary lighting device that compensates for the lack of illuminance in the monitoring area can be optimally controlled according to the illuminance of the monitoring area. An object of the present invention is to improve the performance of a surveillance camera system that detects an intruder, monitors an article, and the like by reliably compensating for the lack of illuminance in a monitoring area.

[0006]

In order to achieve the above object, an image pickup apparatus provided with a solid-state image pickup device, and a video signal obtained by picking up an image of a monitoring area by the image pickup apparatus are processed to detect an intruder. A surveillance camera system including an image recognition device that performs detection and monitoring of an article, and an auxiliary lighting device that compensates for insufficient illuminance in the monitoring region, and based on the video signal output from the solid-state imaging device, An electronic shutter that determines the number of shutter pulses for controlling a shutter speed of an electronic shutter function for controlling a charge accumulation time of a solid-state imaging device and sends the shutter pulse to the solid-state imaging device while outputting the number of shutter pulses. A control unit configured to control a gain by changing a gain control voltage value based on the video signal output from the solid-state imaging device; An automatic gain control unit for outputting the gain control voltage value while outputting the video signal at a constant level to the device, the number of shutter pulses output from the electronic shutter control unit, and an output from the automatic gain control unit. Based on the gain control voltage value to be determined, the brightness of the monitoring area is determined, a determining unit that determines whether to turn on or off the auxiliary lighting device, based on a determination result of the determining unit A lighting control unit that controls turning on and off of the auxiliary lighting device.

In addition, when the auxiliary lighting device is turned on, the determination unit compares the number of shutter pulses with an upper limit reference pulse number, and when the number of shutter pulses is equal to or greater than the upper limit reference pulse number, The monitor area is determined to be bright, and when the auxiliary lighting device is turned off, the determination unit compares the shutter pulse number with a lower-limit reference pulse number and determines the gain control voltage value as a reference. Compared with a voltage value, when the shutter pulse number is equal to or less than the lower limit reference pulse number, or when the gain control voltage value is equal to or less than the reference voltage value, the brightness of the monitoring area is determined to be dark. .

The determining unit determines that the auxiliary lighting device is turned on immediately when the brightness of the monitored area is determined to be dark, and determines that the brightness of the monitored area is bright when determined that the brightness of the monitored area is dark. After the elapse of a predetermined time, it is determined whether to turn off the auxiliary lighting device.

[0009] The determination unit may determine to turn off the auxiliary lighting device when the number of times of determining that the brightness of the monitoring area is bright within a predetermined time is equal to or more than a predetermined number.

[0010] Further, the determining unit determines that the auxiliary lighting device is turned off when it is determined that the brightness of the monitoring area is bright continuously for a predetermined time.

[0011] The determination section may repeatedly perform an operation of determining whether to turn on the auxiliary lighting device and an operation of determining whether to turn off the auxiliary lighting device.

Further, when the auxiliary lighting device is turned on, the determination unit performs an operation of determining whether to turn off the auxiliary lighting device at predetermined time intervals, and the auxiliary lighting device is turned off. In such a case, the operation of determining whether to turn on the auxiliary lighting device is continuously performed.

[0013] Further, the lighting control section gradually darkens the light when controlling the turning off of the auxiliary lighting device.

[0014] Further, the auxiliary lighting device is turned on at the time when the imaging device starts imaging the monitoring area.

[0015] Alternatively, an image pickup apparatus provided with a solid-state image pickup device and an image recognition apparatus for processing an image signal obtained by picking up an area to be monitored by the image pickup apparatus and detecting an intruder or monitoring an article. A surveillance camera system, comprising: an auxiliary lighting device that compensates for insufficient illuminance in the monitoring area; and an electronic shutter function that controls a charge accumulation time of the solid-state imaging device based on the video signal output from the solid-state imaging device. An electronic shutter control unit that determines the number of shutter pulses for controlling the shutter speed and sends the shutter pulses to the solid-state imaging device, and outputs the number of shutter pulses, and is output from the electronic shutter control unit. Based on the shutter pulse number, determine the brightness of the monitoring area, whether to turn on or off the auxiliary lighting device A determination unit for determining, and a lighting control section that controls the turning on and off of the determination of the determination result the auxiliary lighting apparatus based on.

When the auxiliary lighting device is turned on, the determination section compares the shutter pulse number with an upper limit reference pulse number set to the same value as the maximum pulse number, and determines that the shutter pulse number is equal to the upper limit number. When the number of reference pulses coincides with the reference pulse number, the brightness of the monitoring area is determined to be bright.When the auxiliary lighting device is turned off, the determination unit sets the shutter pulse number to a predetermined number from the minimum pulse number. When the shutter pulse number is equal to or smaller than the lower limit reference pulse number, the brightness of the monitoring area is determined to be dark.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a main block diagram showing a surveillance camera system according to the present invention, FIG. 2 is a diagram for explaining a control range of a shutter speed and a control range of a gain with respect to brightness of a surveillance area, and FIG. It is a flowchart for explaining the operation content of determining the brightness of the area and determining whether to turn on or off the auxiliary lighting device,
4 and 5 are flowcharts for explaining the operation of determining that the brightness of the monitoring area is bright and determining whether or not to turn off the auxiliary lighting device after a predetermined time has elapsed.
5 is a flowchart for explaining the operation of determining the brightness of the monitoring area and determining whether to turn on or off the auxiliary lighting device. In FIG. 1, 1 is an imaging device, 2 is an image recognition device, 3 is an auxiliary lighting device, 4 is a solid-state imaging device, 5 is an electronic shutter control unit, 6 is an automatic gain control unit, 7 is a judgment unit, and 8 is an image processing unit. , 9 is a light source and 10 is an illumination control unit. The imaging device 1 includes a solid-state imaging device 4, an electronic shutter control unit 5, and an automatic gain control unit 6, and is installed so as to be able to image a monitoring area. The image recognition device 2 includes a determination unit 7 and an image processing unit 8. The auxiliary lighting device 3 is a light source 9
And an illumination control unit 10, and are installed near the installation location of the imaging device 1 so as to compensate for the lack of illuminance in the monitoring area.

In the above configuration, the operation of each part of the surveillance camera system according to one embodiment of the present invention will be described in detail. The solid-state imaging device 4 has an electronic shutter function such as C
A semiconductor element such as a CD or a CMOS, which photoelectrically converts incident light incident through an imaging lens (not shown) and accumulates the electric charge in each pixel. The accumulated electric charge is swept out by a read pulse to generate a video signal (image data). ).

The electronic shutter controller 5 controls the solid-state image sensor 4 based on the video signal output from the solid-state image sensor 4.
The number of shutter pulses for controlling the shutter speed of the electronic shutter function for controlling the electric charge accumulation time is determined, the shutter pulses are sent to the solid-state imaging device 4, and the number of shutter pulses is output to the determination unit 7. For example, a video signal output from the solid-state imaging device 4 is sampled and held, a value integrated by a low-pass filter is compared with two reference values, and when the value integrated by the low-pass filter is equal to or greater than the two reference values, the shutter is released. The number of pulses is increased, and when the number is equal to or smaller than the reference value, the number of shutter pulses is reduced. That is, by integrating the output of the solid-state imaging device 4, the average brightness of the monitoring area is detected, and the electronic shutter control unit 5 increases the number of shutter pulses according to the integration value when the monitoring area is bright, Conversely, when the monitoring area is dark, the number of shutter pulses is reduced and the shutter pulses are sent to the solid-state imaging device 4.

While the shutter pulse is being sent to the solid-state imaging device 4 having the electronic shutter function, the electric charge accumulated in each pixel of the solid-state imaging device 4 is discarded. The imaging element 4 starts accumulating charges in each pixel. Therefore, the period from the stop of the transmission of the shutter pulse to the reception of the read pulse is the charge accumulation time. That is, when the monitoring area is bright, the charge accumulation time is shortened by increasing the number of shutter pulses to the solid-state image sensor 4, and when the monitoring area is dark, the charge accumulation time is decreased by decreasing the number of shutter pulses. Becomes longer.

More specifically, when photographing is performed at 60 frames per second, the charge storage time for one frame image is at most about 1/60 second. For example, when the number of shutter pulses is 1, the charge storage time is 1/60 seconds. When the number of shutter pulses is 249, the shutter pulse is determined so that the charge accumulation time is about 1/1400 seconds. In order to further reduce the charge accumulation time, the number of shutter pulses is fixed at 250, and the 250th pulse is moved linearly. That is, when the number of shutter pulses to the solid-state imaging device 4 increases, the shutter speed increases, and when the number of shutter pulses decreases, the shutter speed decreases.

As described above, the shutter speed of the electronic shutter function is controlled by transmitting the shutter pulse to the solid-state imaging device 4, and the average luminance level of the video signal from the solid-state imaging device 4 is changed by changing the charge accumulation time. Is output at a constant value. Then, the electronic shutter control unit 5 sends a shutter pulse to the solid-state imaging device 4, and outputs the number of shutter pulses to the determination unit 7 in a range of, for example, 1 to 250 according to the brightness of the monitoring area.

The automatic gain control unit 6 controls the gain by changing the gain control voltage value of the amplifier based on the video signal output from the solid-state imaging device 4, and controls the image processing device 2 to keep the level of the video signal constant. And outputs the gain control voltage value to the determination unit 7. For example, when the monitoring area is dark, the average luminance level of the video signal output from the solid-state imaging device 4 provided in the imaging device 1 decreases. The average luminance level is compared with the reference level, and the gain is controlled in accordance with the brightness of the monitoring area so that the average luminance level of the video signal is output at a constant level. Then, the automatic gain control unit 6
For example, when the monitoring area is bright, the gain is 0 dB and the gain control voltage value is 4 V. When the monitoring area is dark, the gain is 30 dB.
B, the gain control voltage value is set to 2 V, and the video signal level is output to the image processing device 2 at a constant level, while the gain control voltage value is set to 2 V to 4 V according to the brightness of the monitoring area to the determination unit 7
Output in the range of.

In the present embodiment, the brightness of the monitoring area is controlled by controlling the shutter speed of the electronic shutter function so that the average brightness level of the video signal from the solid-state imaging device 4 is kept constant, and As shown in FIG. 2, electronic shutter control is prioritized, and the number of shutter pulses is 1 (the charge accumulation time is 1), as shown in FIG. / 60 seconds), the gain control voltage value is set to 4 V (gain is 0 dB), and the shutter speed is controlled on the bright side of the monitoring area, and the gain is controlled on the dark side of the monitoring area. In addition, when the average luminance level of the video signal is output at a constant level by controlling the gain of the amplifier, a noise component included in the video signal is also amplified.
By controlling the shutter speed of the electronic shutter function as much as possible, the range in which the average luminance level of the video signal from the solid-state imaging device 4 is output at a constant level is widened, and the range in which the gain of the amplifier on the dark side is controlled is controlled. The lighting device 3 is turned on early to compensate for the lack of illuminance in the monitoring area.

The determination section 7 determines the brightness of the monitoring area based on the number of shutter pulses output from the electronic shutter control section 5 and the gain control voltage value output from the automatic gain control section 6 as described later. To turn on or off the auxiliary lighting device 3.

The image processing unit 8 processes a video signal (image data) obtained by imaging the monitoring area by the imaging device 1 based on a program stored in a built-in ROM.
For example, the background image data when there is no monitoring target in the monitoring area previously obtained by the imaging device 1 and the imaging device 1
By comparing the difference (difference image data) with the surveillance image data for monitoring whether or not there is a monitoring target obtained by the above with a binarization threshold, the binarization image data is obtained. Get
Based on the binarized image data, detection of an intruder, monitoring of articles, and the like are performed, and background image data and surveillance image data are arranged at a monitoring center or the like as image data for display. Output to a monitor (not shown).

The light source 9 is, for example, an incandescent light bulb such as a halogen lamp, and when turned on, makes up for insufficient illuminance when the monitoring area is dark. The lighting control unit 10 determines based on the determination result of the determination unit 7, that is, whether the auxiliary lighting device 3 is turned on or off.
Lighting / extinguishing of the light source 9 is controlled.

As described above, each part of the surveillance camera system according to one embodiment of the present invention operates. Next, based on the flowchart shown in FIG. 3, the operation of determining the brightness of the monitoring area by the determination unit 7 and determining whether to turn on or off the auxiliary lighting device 3 will be described in detail. In addition, the following ST numbers indicate each step in FIG. 3 and FIGS. First, when the surveillance camera system starts detection of an intruder, monitoring of an article, or the like, that is, at the time of starting imaging of a monitoring area by the imaging device 1, the auxiliary lighting device 3 is turned on (ST1). This is to ensure that when the monitoring area is dark, the illuminance shortage of the monitoring area can be compensated without waiting for the determination operation described below.

The ON / OFF state of the auxiliary lighting device 3 is confirmed (ST2). Here, when the auxiliary lighting device 3 is in the lighting state, the number of shutter pulses output from the electronic shutter control unit 5 is compared with the upper limit reference pulse number (for example, 250), and the shutter pulse number must be equal to or larger than the upper limit reference pulse number. In this case, the lighting state of the auxiliary lighting device 3 is maintained (ST
3) If the number of shutter pulses is equal to or greater than the upper limit reference pulse number, the brightness of the monitoring area is determined to be bright, the auxiliary lighting device 3 is turned off (ST4), and the process returns to ST2. on the other hand,
When the auxiliary lighting device 3 is turned off in the process of ST2, the number of shutter pulses output from the electronic shutter control unit 5 is compared with the lower limit reference pulse number (for example, 50) and output from the automatic gain control unit 6. The gain control voltage value is compared with a reference voltage value (for example, 3.5 V). If the shutter pulse number is not less than the lower reference pulse number and the gain control voltage value is not less than the reference voltage value, the auxiliary lighting device 3 is turned off. The state is maintained (ST5), and when the shutter pulse number is equal to or less than the lower limit reference pulse number or the gain control voltage value is equal to or less than the reference voltage value, it is determined that the brightness of the monitoring area is dark, and the auxiliary lighting device 3 is determined. Is turned on (ST6), and S
It returns to the process of T2.

For example, from the state where the monitoring area is bright and the number of shutter pulses is 250 and the auxiliary lighting device 3 is off, the environment in which the monitoring camera system is installed suddenly darkens and the monitoring area becomes insufficient in illuminance. In this case, the number of shutter pulses decreases and the number of shutter pulses decreases by one.
Before the gain control voltage value starts dropping from 4V. Therefore, even if the shutter pulse number is, for example, 100 during the decrease, the gain control voltage value is changed to 3.5 V or less. The brightness of the monitoring area is determined using the voltage value. By doing so, the auxiliary lighting device can be always turned on when the monitoring area is dark, and insufficient illuminance in the monitoring area can be surely compensated.

After the auxiliary lighting device 3 is turned off by the process of ST4, the process proceeds to the operation ST5 for determining whether or not the auxiliary lighting device 3 is turned on, and the auxiliary lighting device 3 is turned on by the process of ST6. After that, the process may proceed to the process of operation ST3 for determining whether or not to turn off the auxiliary lighting device 3. If the auxiliary lighting device 3 is turned on in the process of ST1, Auxiliary lighting device 3
It is also possible to omit the process of ST2 for checking the lighting / light-off state of. Then, an operation of determining whether to turn on the auxiliary lighting device 3 and an operation of determining whether to turn off the auxiliary lighting device 3 are repeatedly performed.

In the process of ST5, when the lighting condition of the auxiliary lighting device 3 is satisfied (when the number of shutter pulses is equal to or less than the lower limit reference pulse number or the gain control voltage value is equal to or less than the reference voltage value), the monitoring area is set. Is determined to be dark, and the auxiliary lighting device 3 is immediately turned on.
In the process of T3, when the condition for turning off the auxiliary lighting device 3 is satisfied (when the number of shutter pulses is equal to or more than the upper limit reference pulse number), it is determined that the brightness of the monitoring area is bright, and after a predetermined time has elapsed, the auxiliary lighting device 3 is turned off. The auxiliary lighting device 3 may be turned off when it is determined whether to turn off the light or not.

FIG. 4 shows an example in which in the process of ST4 shown in FIG. 3, it is determined whether or not the auxiliary lighting device 3 is turned off after a lapse of a predetermined time without turning off the auxiliary lighting device 3 immediately. This will be described in detail based on a flowchart. S
In the process of T3 (FIG. 3), when the turn-off condition of the auxiliary lighting device 3 is satisfied (when the number of shutter pulses is equal to or more than the upper limit reference pulse number), a timer for measuring time is started and the number N of times that the turn-off condition is satisfied is calculated. The counter value N to be counted is set to 0 (ST11). Subsequently, the counter value N is set to 1 (N = N + 1) (ST12). Then, it is determined whether or not a predetermined time (for example, 30 seconds) has elapsed since the turning-off condition (ST3) of the auxiliary lighting device 3 is satisfied (ST1).
3) If the predetermined time has not elapsed, the number of shutter pulses is compared with the upper limit reference pulse number (for example, 250) (ST14). If the number of shutter pulses is equal to or more than the upper limit reference pulse number in the process of ST14, it is determined that the brightness of the monitoring area is bright, the process proceeds to ST12, the counter value N is set to 2 (N = N + 1), and the process proceeds to ST13.
If the number of shutter pulses is not equal to or greater than the upper limit reference pulse number in the process of ST14, the process proceeds to ST13. Then, in the process of ST13, it is determined whether or not a predetermined time has elapsed since the turning-off condition (ST3) of the auxiliary lighting device 3 is satisfied. If the predetermined time has not elapsed, the process proceeds to ST14 and the above operations are repeated. By this repetition, a comparison as to whether the light-off condition is satisfied or not is made 150 times, for example, 5 times / 1 second until a predetermined time elapses.

On the other hand, if it is determined that the predetermined time has elapsed in the process of ST13, it is determined whether the number N of times that the light-off condition is satisfied within the predetermined time is a predetermined number (for example, 145) or more (ST15). The number of times N satisfying the condition,
That is, when the number of times that the brightness of the monitoring area is determined to be bright is equal to or more than the predetermined number, it is determined that the auxiliary lighting device 3 is turned off, the auxiliary lighting device 3 is turned off (ST16), the timer is cleared, and the counter value N is reset. Set to 0 (ST1
7). If the number of times N that satisfies the light-off condition, that is, the number of times that the brightness of the monitoring area is determined to be bright, is not a predetermined number or more, the lighting state of the auxiliary lighting device 3 is maintained and the process proceeds to ST17. Then, for example, the process returns to ST2 (FIG. 3).

In the process of ST4 shown in FIG.
Another example of determining whether to turn off the auxiliary lighting device 3 after a lapse of a predetermined time without immediately turning off the auxiliary lighting device 3 will be described in detail with reference to a flowchart shown in FIG. In the process of ST3 (FIG. 3), the auxiliary lighting device 3
When the light-off condition is satisfied (when the number of shutter pulses is equal to or more than the upper limit reference pulse number), a timer for measuring time is started (ST21). And the auxiliary lighting device 3
It is determined whether a predetermined time (for example, 15 seconds) has elapsed since the turning-off condition (ST3) is satisfied (ST22). If the predetermined time has not elapsed, the number of shutter pulses is compared with the upper limit reference pulse number (for example, 250). (ST23). ST2
If the number of shutter pulses is equal to or greater than the upper-limit reference pulse number in the process of step 3, it is determined that the brightness of the monitoring area is bright, and the process returns to step ST22 to turn off the auxiliary lighting device 3 (S
It is determined whether a predetermined time has elapsed after satisfying T3). If the predetermined time has not elapsed, the process proceeds to ST23 and the above operations are repeated. On the other hand, when it is determined that the predetermined time has elapsed in the process of ST22, it is determined that the auxiliary lighting device 3 is turned off, the auxiliary lighting device 3 is turned off (ST24), and the timer is cleared (ST25). If the number of shutter pulses is not equal to or larger than the upper limit reference pulse number in the process of ST23, the lighting state of the auxiliary lighting device 3 is maintained and the process of ST2 is performed.
Move to processing of 5. Then, for example, the process returns to ST2 (FIG. 3).

In the process shown in FIG. 5, instead of using a timer for measuring time, a counter for counting the number N of times that the light-off condition is satisfied is used, and the counter value N is increased each time the light-off condition is continuously satisfied ( (N = N + 1), when the light-off condition is satisfied continuously for a predetermined number of times (for example, 75 times), it is determined that the auxiliary lighting device 3 is turned off, the auxiliary lighting device 3 is turned off, and the counter value N is set to 0. If the number of shutter pulses does not become equal to or more than the upper limit reference pulse number before satisfying the light-off condition continuously for a predetermined number of times, the lighting state of the auxiliary lighting device 3 is maintained and the counter value N is set to 0. Then, for example, the process returns to ST2 (FIG. 3).

As described above, when the lighting condition of the auxiliary lighting device 3 is satisfied, the brightness of the monitoring area is determined to be dark, and the auxiliary lighting device 3 is turned on immediately. When the condition is satisfied, it is determined that the brightness of the monitoring area is bright. However, by not turning off the auxiliary lighting device 3 immediately and determining whether to turn off the auxiliary lighting device 3 after a lapse of a predetermined time, When the surveillance area is dark, for example, when the environment in which the surveillance camera system is installed temporarily becomes bright and then immediately becomes dark, the auxiliary lighting device 3
Are maintained in the lighting state, and the lack of illuminance in the monitoring area can be compensated.

Further, as another example in which the auxiliary lighting device 3 is not turned off immediately when the monitoring area temporarily becomes bright, the auxiliary lighting device 3 is turned off when the auxiliary lighting device 3 is turned on. The operation of determining whether or not to perform the operation is performed at predetermined time intervals. When the auxiliary lighting device 3 is turned off, the operation of determining whether to turn on the auxiliary lighting device 3 is continuously performed. Is also good. In addition, the auxiliary lighting device 3
Is turned off gradually, and the auxiliary lighting device 3 is turned on immediately with a predetermined brightness that compensates for the lack of illuminance in the monitoring area.

In the above example, the determination unit 7 is provided in the image recognition device 2, and the number of shutter pulses and the gain control voltage value are output from the imaging device 1 to the image recognition device 2, and the auxiliary illumination device 3 is output from the image recognition device 2. Although the control signal for turning on / off is output to the imaging device 1, the determination unit 7 is provided in the imaging device 1, so that the lighting device 3 is turned on / off from the imaging device 1 to the auxiliary lighting device 3 installed near the installation location of the imaging device 1. The light-off control signal may be directly output.

In the above example, the determination unit 7 determines the monitoring area based on the number of shutter pulses output from the electronic shutter control unit 5 and the gain control voltage value output from the automatic gain control unit 6 as described above. The brightness of the monitoring area is determined based on only the number of shutter pulses without using the gain control voltage value. Whether to turn on or off the device 3 may be determined.

Another example of determining the brightness of the monitoring area by the determination section 7 and determining whether to turn on or off the auxiliary lighting device 3 will be described in detail with reference to the flowchart shown in FIG. First, the auxiliary lighting device 3 is turned on (ST3).
1). Since the auxiliary lighting device 3 is in a lighting state, the number of shutter pulses output from the electronic shutter control unit 5 is compared with the upper limit reference pulse number (for example, 250) set to the same value as the maximum pulse number, and the upper limit of the number of shutter pulses is set. If the number does not match the reference pulse number, the lighting state of the auxiliary lighting device 3 is maintained (ST32). If the number of shutter pulses matches the upper limit reference pulse number, the brightness of the monitoring area is determined to be bright, and the auxiliary lighting device is determined. 3 is turned off (ST33), and an operation of determining whether to turn on the auxiliary lighting device 3 (ST34).
Move to Subsequently, since the auxiliary lighting device 3 is in an extinguished state,
The number of shutter pulses output from the electronic shutter control unit 5 is compared with a lower limit reference pulse number (for example, 100) set to a value larger than the minimum pulse number by a predetermined number. The auxiliary lighting device 3 is kept off (ST34), and when the shutter pulse number is equal to or less than the lower limit reference pulse number, the brightness of the monitoring area is determined to be dark, and the auxiliary lighting device 3 is turned on (S34).
T35), the process proceeds to an operation of determining whether to turn off the auxiliary lighting device 3 (ST32). Then, an operation of determining whether to turn on the auxiliary lighting device 3 and an operation of determining whether to turn off the auxiliary lighting device 3 are repeatedly performed.

The lower limit reference value for determining whether to turn on the auxiliary lighting device 3 is set to a value larger than the minimum number of shutter pulses output from the electronic shutter control unit 5 by a predetermined number, thereby enabling monitoring. For example, when the environment in which the camera system is installed becomes darker, the auxiliary lighting device 3 can be turned on early. When the monitoring area is dark, the auxiliary lighting device 3 is always kept in the lighting state, Insufficient illumination can be compensated.

[0043]

According to the monitoring apparatus described above, an intruder is detected by processing a video signal obtained by capturing an image of a monitoring area by an imaging apparatus (for example, a CCD camera) having a solid-state imaging device. When monitoring objects and goods, the brightness of the monitoring area is correctly determined based on the number of shutter pulses and the gain control voltage value, or the number of shutter pulses.
Lighting / extinguishing of the auxiliary lighting device that compensates for the lack of illuminance in the monitoring area can be optimally controlled according to the illuminance in the monitoring area, and uses an optical sensor that does not consume unnecessary power and is not necessary for direct monitoring. The auxiliary lighting device can always be kept on when the monitoring area is dark and the lack of illuminance in the monitoring area can be surely compensated to detect intruders and monitor items. it can.

[Brief description of the drawings]

FIG. 1 is a main block diagram showing a surveillance camera system according to the present invention.

FIG. 2 is a diagram for explaining a control range of a shutter speed and a control range of a gain with respect to brightness of a monitoring area.

FIG. 3 is a flowchart illustrating an operation of determining the brightness of a monitoring area and determining whether to turn on or off an auxiliary lighting device.

FIG. 4 is a flowchart illustrating an operation of determining that the brightness of the monitoring area is bright and determining whether to turn off the auxiliary lighting device after a predetermined time has elapsed.

FIG. 5 is a flowchart illustrating another operation of determining that the brightness of the monitoring area is bright, and determining whether to turn off the auxiliary lighting device after a predetermined time has elapsed.

FIG. 6 is a flowchart for explaining another operation content for determining the brightness of the monitoring area and determining whether to turn on or off the auxiliary lighting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging device 2 image recognition device 3 auxiliary lighting device 4 solid-state imaging device 5 electronic shutter control unit 6 automatic gain control unit 7 determination unit 8 image processing unit 9 light source 10 illumination control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C022 AA01 AB15 AB65 AC52 AC69 CA00 5C054 AA01 CA04 CB02 CB04 CC05 CH02 FA09 FC03 FF02 HA18 HA19 5C084 AA02 AA07 AA13 BB32 CC17 DD11 EE01 GG33 GG39 GG44 GG57 GG80

Claims (11)

[Claims] 1. An imaging device having a solid-state imaging device, and an image recognition device that processes a video signal obtained by imaging a monitoring area by the imaging device to detect an intruder, monitor an article, and the like. A surveillance camera system, comprising: an auxiliary lighting device that compensates for insufficient illuminance in the monitoring area; and an electronic shutter function that controls a charge accumulation time of the solid-state imaging device based on the video signal output from the solid-state imaging device. An electronic shutter control unit that determines the number of shutter pulses for controlling the shutter speed, sends the shutter pulse to the solid-state imaging device, and outputs the number of shutter pulses, and outputs the number of shutter pulses from the solid-state imaging device. Based on the video signal, the gain is controlled by changing the gain control voltage value, and the level of the video signal is output to the image recognition device while the level is kept constant. On the other hand, based on the automatic gain control unit that outputs the gain control voltage value, based on the number of shutter pulses output from the electronic shutter control unit and the gain control voltage value output from the automatic gain control unit,
A determining unit that determines the brightness of the monitoring area and determines whether to turn on or off the auxiliary lighting device; and an illumination control that controls turning on and off the auxiliary lighting device based on a determination result of the determining unit. A surveillance camera system, comprising: 2. When the auxiliary lighting device is turned on,
The determination unit compares the number of shutter pulses with an upper-limit reference pulse number, and determines that the brightness of the monitoring area is bright when the number of shutter pulses is equal to or greater than the upper-limit reference pulse number. When the lighting device is turned off, the determination unit compares the shutter pulse number with a lower reference pulse number and compares the gain control voltage value with a reference voltage value, and the shutter pulse number is equal to or less than the lower reference pulse number. Or when the gain control voltage value is equal to or lower than a reference voltage value, the brightness of the monitoring area is determined to be dark.
The surveillance camera system as described. 3. The determination unit determines that the auxiliary lighting device is turned on immediately when determining that the brightness of the monitoring area is dark, and determines that the brightness of the monitoring area is bright when determining that the brightness of the monitoring area is dark. The surveillance camera system according to claim 1 or 2, wherein it is determined whether or not the auxiliary lighting device is turned off after a predetermined time has elapsed. 4. The method according to claim 1, wherein the determining unit determines to turn off the auxiliary lighting device when the number of times of determining that the brightness of the monitoring area is bright within a predetermined time is equal to or more than a predetermined number. The surveillance camera system according to claim 3, wherein 5. The method according to claim 3, wherein the determining unit determines to turn off the auxiliary lighting device when it is determined that the brightness of the monitoring area is bright continuously for a predetermined time. Surveillance camera system. 6. The method according to claim 1, wherein the determining unit repeatedly performs an operation of determining whether to turn on the auxiliary lighting device and an operation of determining whether to turn off the auxiliary lighting device. The surveillance camera system according to claim 1. 7. When the auxiliary lighting device is on, the determination unit performs an operation of determining whether to turn off the auxiliary lighting device at predetermined time intervals, and the auxiliary lighting device is turned off. The surveillance camera system according to claim 1, wherein, when performing the operation, an operation of determining whether to turn on the auxiliary lighting device is continuously performed. 8. The surveillance camera system according to claim 1, wherein the lighting control unit gradually darkens the light when controlling the turning off of the auxiliary lighting device. 9. The surveillance camera system according to claim 1, wherein the auxiliary lighting device is turned on when the imaging device starts imaging the monitoring area. 10. An imaging device having a solid-state imaging device, and an image recognition device that processes a video signal obtained by imaging a monitoring area by the imaging device to detect an intruder, monitor an article, and the like. A surveillance camera system, comprising: an auxiliary lighting device that compensates for insufficient illuminance in the monitoring area; and an electronic shutter function that controls a charge accumulation time of the solid-state imaging device based on the video signal output from the solid-state imaging device. An electronic shutter control unit that determines the number of shutter pulses for controlling the shutter speed and sends the shutter pulses to the solid-state imaging device, and outputs the number of shutter pulses, and is output from the electronic shutter control unit. Based on the shutter pulse number, determine the brightness of the monitoring area, and determine whether to turn on or off the auxiliary lighting device A surveillance camera system, comprising: a determination unit that performs lighting and a lighting control unit that controls turning on and off of the auxiliary lighting device based on a determination result of the determination unit. 11. When the auxiliary lighting device is turned on, the determination unit compares the shutter pulse number with an upper limit reference pulse number set to the same value as a maximum pulse number, and determines that the shutter pulse number is equal to the upper limit. When the number of reference pulses coincides with the reference pulse number, the brightness of the monitoring area is determined to be bright.When the auxiliary lighting device is turned off, the determination unit sets the shutter pulse number to a predetermined number from the minimum pulse number. Comparing with a lower reference pulse number set to a value larger than the lower reference pulse number, and determining that the brightness of the monitoring area is dark when the shutter pulse number is equal to or less than the lower reference pulse number. 13. The surveillance camera system according to 12.