JPH09284753A - Method and device for controlling image pickup of supervisory camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup controller for a supervisory camera in which the configuration of a signal processing section receiving video signals of plural supervisory cameras is simplified. SOLUTION: The device is provided with a synchronizing signal generator 29 generating a synchronizing signal for a prescribed period and a camera controller 28 controlling the image pickup motion of plural supervisory cameras 25 to 27 arranged side by side in a broadwise direction at a right angle to a moving direction of a moving object 24 to be supervised and each consisting of a linear CCD camera according to the synchronizing signal. The controller is provided with a start signal generating section 28a generating a camera start signal for each camera at each prescribed time from the received synchronizing signal and an image pickup control section 28b providing the start signal to each camera in the arranged order to allow each camera to conduct image pickup operation. Then each video signal outputted from each camera is made continuous serially in time series so that the signals are equivalently synthesized as one scanning signal along with the broadwise direction of the moving object apparently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a size measuring device for measuring the size of a moving object or a defect inspection device for inspecting the defect of the moving object. The present invention relates to a method and an apparatus for controlling image pickup of a surveillance camera which is a linear CCD camera used for obtaining the above.

[0002]

2. Description of the Related Art As shown in FIG. 3, a defect inspection apparatus for inspecting a material to be inspected, such as a moving printed matter, comprises a monitoring section 1, a signal processing section 2, and a judging section 3. It has a system configuration.

A plurality of monitoring units 1 are arranged side by side in the width direction (direction intersecting at right angles to the moving direction of the test material 4) of the test material 4 which is moved in the front and back directions of the paper surface shown in FIG. In addition to the surveillance cameras 5 to 8, the camera controller 9 is provided. Each of the monitoring cameras 5 to 8 is a so-called linear CCD camera, which uses a linear CCD image sensor as a light receiving element 5a to 8a that outputs a voltage corresponding to the intensity of light received by the monitoring camera as a video signal. Has been done. The camera controller 9 controls the image pickup operations of the surveillance cameras 5 to 8 simultaneously and individually.

By the way, when the inspection information is obtained by using only one high-resolution linear CCD camera having a large number of photosensitive elements, the surveillance camera and the material 4 to be inspected due to the angle of view of the surveillance camera. It is known that it is difficult to arrange the surveillance camera if the above-mentioned arrangement distance cannot be ensured due to the surrounding conditions due to the restriction on the camera arrangement that it is necessary to ensure a certain arrangement distance between them. Has been. As a countermeasure, if the objective lens of the surveillance camera has an appropriate f value, the arrangement distance can be shortened.
In that case, the aberration of the objective lens largely affects the inspection information, which is not preferable. Instead of this, instead of one monitoring camera, a plurality of monitoring cameras having a small angle of view are arranged side by side in the width direction of the material to be inspected 4, and each of the monitoring cameras partially captures the image of the material to be inspected. If the above is shared with the above, it is possible to shorten the arrangement distance between these cameras and the material to be inspected while preventing the influence of the aberration of each surveillance camera. Moreover, since the fields of view of the monitoring cameras arranged side by side in this way are small, even if the resolution of each camera is lowered, the number of photosensitive elements in the entire monitoring unit is equivalent to that of the single monitoring camera of high resolution, or It is excellent in that it can achieve higher resolution.

Therefore, as shown in FIG. 3, a configuration in which a plurality of monitoring cameras 5-8 are arranged in parallel and inspection information is obtained by these cameras 5-8 is used when the width of the material 4 to be inspected is large or when the inspection is performed. This is effective when pursuing improvement in accuracy.

Further, the signal processing unit 2 includes a surveillance camera 5
8 to 8 have signal processing units 10 to 13 individually corresponding thereto, and video signals output from the corresponding monitoring cameras 5 to 8 are individually supplied to these. Each of the signal processing units 10 to 13 processes the video signal supplied thereto to detect defects, for example. Such parallel processing is effective in maximizing the scanning rate of each surveillance camera 5-8, and is also effective in maximizing the processing capability of each signal processing unit 10-13 accordingly. Therefore, it is suitable when the moving speed of the test material 4 is particularly high.

Further, the defect information detected individually in each of the signal processing units 10 to 13 is supplied to the judgment unit 3 composed of a CPU or the like. In the judgment unit 3, whether the supplied defect information is worth a defect or not. And the position of the defect thus determined on the material 4 to be inspected. Then, those judgment outputs are supplied to an appropriate recording device such as a printer (not shown).

[0008]

As described above, conventionally,
The plurality of monitoring cameras 5 to 8 arranged in parallel are simultaneously driven by the camera controller 9, and the video signals thereof are output in parallel and individually supplied to the respective signal processing units 10 to 13 of the corresponding signal processing unit 2. Has been done. Further, such a conventional configuration is applied to a moving object having a high moving speed and a moving object having a low moving speed. Therefore, in the system configuration such as the defect inspection, the signal processing unit 2 requires the same number of signal processing units 10 to 13 as the number of the monitoring cameras 5 to 8 in accordance with the signal processing of each video signal of the monitoring cameras 5 to 8. However, there is a problem that the system configuration is complicated and expensive.

Therefore, the problem to be solved by the present invention is to obtain an image pickup control method for a surveillance camera and an apparatus therefor capable of simplifying the configuration of a signal processing unit to which the video signals of a plurality of surveillance cameras are supplied. .

[0010]

In order to solve the above-mentioned problems, the method of the present invention according to claim 1 is arranged in parallel with a moving object to be monitored in a direction intersecting at right angles with the moving object, A plurality of surveillance cameras, each of which is a linear CCD camera that partially shares and captures images, are imaged in the order in which the surveillance cameras are arranged according to a camera start signal generated at regular intervals based on the same synchronization signal. Then, the video signals of these cameras are extracted, and the extracted video signals are serially serially output in a time series and output.

In the method according to the first aspect of the present invention, a camera start signal for determining the image pickup operation of each of the monitoring cameras arranged in parallel is generated from a common synchronization signal, and the monitoring signals are used to arrange the monitoring cameras in the order of arrangement. Sequential driving is performed, whereby video signals obtained with a time difference one after another are continuously output in series in time series according to the arrangement order of the monitoring cameras. As a result, the respective video signals output from the respective surveillance cameras can be made into a serial composite video signal equivalent to that which is apparently composed as one scanning signal along a direction intersecting at right angles with the moving direction of the moving object. , It can be supplied to the signal processor.

[0012] Similarly, in order to solve the above-mentioned problems, the invention device according to claim 2 is such that a synchronizing signal generator for generating a synchronizing signal at a predetermined cycle and a moving object to be monitored intersect at right angles to the moving direction thereof. Image pickup operation of a plurality of monitoring cameras, which are arranged in parallel in a direction in which the moving objects are partially shared and imaged by partially sharing the moving object, according to the synchronization signal supplied from the synchronization signal generator. A camera controller that controls the camera controller, the camera controller generating a camera start signal corresponding to each surveillance camera from the supplied synchronization signal at regular time intervals, and the camera start An image pickup control unit for giving signals to the respective surveillance cameras in the order of arrangement thereof to cause these surveillance cameras to perform an image pickup operation. Is characterized in that the imaging control, and outputs the time series continuation with serial video signals extracted in order of the surveillance camera according to.

In the invention device of claim 2, the synchronizing signal generator generates the synchronizing signal of a predetermined cycle. The start signal generation unit of the camera controller generates a camera start signal from the synchronization signal generator supplied thereto at regular time intervals. These start signals are individually generated for the monitoring cameras arranged in parallel. The imaging control unit of the camera controller supplies a camera start signal to each of the monitoring cameras arranged side by side in the order in which they are arranged to start and end the imaging operation of these cameras one after another.

Therefore, the apparatus of the present invention implements the method of the first aspect of the present invention so that the respective video signals output from the respective surveillance cameras are apparently intersecting at right angles with the moving direction of the moving object. It is possible to provide a serial composite video signal that is equivalent to being composited as one scanning signal along the line, and supply it to the signal processing unit.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing the system configuration of a defect detection apparatus including an image pickup control apparatus for implementing the image pickup control method for a surveillance camera according to the first embodiment. This defect detecting device includes a monitoring unit 21 as a monitoring unit for obtaining inspection information, a signal processing unit 22 as a signal processing unit, and a determination unit 2 as a determination unit.
3 is provided.

The monitoring unit 21 is a width of a material 24 to be inspected, such as a film of a printed material or a plain material which is moved in the front and back direction of the paper drawing FIG. 1, or a printed circuit board on which a circuit pattern of a copper foil conductor is printed. A plurality of monitoring cameras 25 to 27, for example, three monitoring cameras 25 to 27 arranged in parallel in a direction (direction intersecting at right angles with the moving direction of the material 24 to be inspected) are provided, and these cameras 25 are also provided.
The camera controller 28 for controlling the image pickup operations (1) to (27) is included.

A linear CCD image sensor (also called a line type or one-dimensional CCD image sensor) that outputs a voltage corresponding to the intensity of light received by each of the monitoring cameras 25 to 27 as a video signal. ) Is the light receiving element 25
so-called linear CCDs used as a to 27a
A camera is employed. These surveillance cameras 25-27
Respectively have CCD drivers 25b to 27b for individually driving the light receiving elements 25a to 27a.

Such monitoring cameras 25 to 27 arranged in parallel are provided.
Since the monitoring unit 21 having a group partially takes an image in the width direction of the material 24 to be inspected, which is a moving object, by the monitoring cameras 25 to 27, the angle of view of each of the monitoring cameras 25 to 27 is measured. (Field of view) is small. Therefore, each surveillance camera 25-2
Since 7 can be arranged close to the material 24 to be inspected without being affected by the aberration of the objective lens, it is suitable when the arrangement distance is limited to a small value. In addition, according to the angle of view, even if the resolution per monitoring camera is low, the number of photosensitive elements required to obtain a predetermined resolution can be secured for the entire group of monitoring cameras 25 to 27. Also suitable for pursuing accuracy, and each surveillance camera 25-27
Each of them can use a low-resolution linear CCD camera, and thus the cost of the monitoring unit 21 can be reduced.

If necessary, a light projector (not shown) is used in combination in the monitoring unit 21, and the visual field of each of the monitoring cameras 25 to 27 is illuminated by the light projection so that the defect on the material 24 to be inspected is emphasized. It has become. In addition, the test material 24
Is a translucent film, the light projected from the projector is transmitted through the film and is transmitted to each surveillance camera 25.
The light projectors are arranged so that they can be received by .about.27.

A sync signal generator 29 is connected to the camera controller 28. The synchronization signal generator 29 generates a synchronization signal (clock pulse) at a predetermined cycle, and is composed of one crystal oscillator that is commonly used for the imaging operation of each of the monitoring cameras 25 to 27.

The camera controller 28 to which the synchronizing signal is supplied has a start signal generating section 28a and an image pickup controlling section 28.
b. The start signal generation unit 28a generates a camera start signal individually corresponding to each of the monitoring cameras 25 to 27 from the synchronization signal supplied thereto at regular time intervals.

The pulse interval A (see FIG. 2) of the generated camera start signal is determined by the number of effective pixels of the light receiving elements 25a to 27a included in each of the monitoring cameras 25 to 27.
It is set to an integral multiple of a value obtained by multiplying the number of used vehicles of 5 to 27, for example, 1 time in this embodiment. The number of effective pixels is the number of photosensitive elements in which light is incident on the linear CCD image sensors 25a to 27a in the visual field portion indicated by C in the visual field width B of each of the monitoring cameras 25 to 27 shown in FIG.
The visual field portions C of the adjacent monitoring cameras 25 to 27 are arranged to be continuous in the width direction of the material 24 to be inspected.

The image pickup controller 28b sends a camera start signal to the CCD drivers 25b-2 of the respective surveillance cameras 25-27.
7b is provided to these cameras 25 to 27 in the order of arrangement so as to sequentially switch the imaging operations of these monitoring cameras 25 to 27. For that purpose, a camera start signal is supplied to the light receiving elements 25a to 27a. It has a counter or the like that starts counting the number of photosensitive elements, that is, the number of operation pulses, and counts up when the count reaches the number of effective pixels and is reset to the initial state. The second and subsequent camera start signal generation timings generated at the pulse interval A coincide with the count-up time of the counter. As a result, the counter starts the next counting at the same time as the counting up, and the imaging control unit 28b sequentially performs the imaging operations of the monitoring cameras 25 to 27 as described above according to the above counter operation. Control to switch.

The signal processing unit 22 is commonly used for a plurality of surveillance cameras 25-27. In the first embodiment, one signal processing unit 22 is commonly used for all the surveillance cameras 25 to 27 because the number of surveillance cameras used is small.
The video signals output from the respective surveillance cameras 25 to 27 are supplied to.

The signal processing unit 22 processes a video signal as inspection information supplied thereto to detect a defect. For example, the signal processing unit 22 has a differentiating circuit or a difference circuit, a comparing circuit, and the like, and performs a differential process or a differential process on the supplied video signal and compares the processing information in the comparing circuit, It is determined whether or not the processing information exceeds a threshold value set in the comparison circuit, thereby detecting the presence or absence of a defect.

However, the structure for detecting defects in the signal processing unit 22 may be one that detects defects by pattern matching, or one that detects defects by another suitable method. When the present invention is applied to dimension measurement other than defect detection, the signal processing unit 22 may be configured by an arithmetic circuit for dimension measurement or the like.

Further, the judging section 23 is composed of a CPU or the like, and the defect information detected by the signal processing is supplied to the judging section 23. The determination unit 23 determines the size, length, etc. of the defect information supplied thereto to determine whether or not the defect information is worthy of a defect, and the defect material 24 thus determined on the inspection material 24. The position is determined at. Then, these judgment outputs are supplied as inspection outputs to an appropriate recording device such as a printer (not shown).

The camera controller 28 and the synchronizing signal generator 29 are composed of a plurality of monitoring cameras 25 to 2 arranged in parallel.
No. 7 image pickup control device 30. Hereinafter, the monitoring cameras 25 to 27 by the image pickup control device 30 in the case of detecting a defect in a circuit pattern of a copper foil conductor on a printed wiring board having a relatively low conveyance speed (moving speed) by the defect inspection device having the above-described configuration. The operation will be described with reference to the time chart of FIG. In this defect inspection, since the moving speed of the test material (printed wiring board) 24 is slow,
For example, the driving frequency (scan rate) of each of the monitoring cameras 25 to 27 is 10 MHz and the number of photosensitive elements is 1000, whereas the driving frequency of the signal processing unit 22 is 10 MHz and the number of cells corresponding to the number of photosensitive elements is 2000. Yes, surveillance camera 2
There is a surplus in the processing capacity of the signal processing unit 22 as compared with the imaging capacities of 2 to 27.

When the defect inspection device having the above-mentioned configuration is operated,
The synchronization signal generator 29 generates a synchronization signal at a predetermined cycle, and this signal is supplied to the start signal generation unit 28a of the camera controller 28. Therefore, the generation unit 28a generates a camera start signal from the synchronization signal at regular time intervals. To generate. As a result, this start signal is given to the monitoring cameras 25 to 27 arranged in parallel via the imaging control unit 28b of the camera controller 28 in the order of arrangement.

For example, first, the first camera start signal D1 to the first surveillance camera 25 is given to cause the camera 25 to perform the image pickup operation. At this time, the imaging control unit 2
The counter 8b starts counting the number of effective pixels scanned by the first surveillance camera 25 with the first camera start signal D1 as a reference, and counts up when the counted number reaches the number of effective pixels. As a result, the imaging operation of the first surveillance camera 25 is stopped. In addition, when the first monitoring camera 25 is performing an image capturing operation, the second monitoring camera 26
The third surveillance camera 27 and the third surveillance camera 27 are both in the imaging standby state.

Simultaneously with the count-up, the start signal generator 28a generates a second camera start signal D2, and this signal D2 is given to the second surveillance camera 26 via the image pickup controller 28b. As a result, the imaging operation of the first surveillance camera 25 is stopped and the imaging operation of the second surveillance camera 26 is started at the same time. Then, similarly to the above, the counter of the imaging control unit 28b starts counting the number of effective pixels scanned by the second surveillance camera 26 with the second camera start signal D2 as a reference, and the counted number is the effective pixel number. When it reaches, it will count up. As a result, the imaging operation of the second surveillance camera 26 is stopped. In addition, when the second monitoring camera 26 is performing an image capturing operation,
Both the first surveillance camera 25 and the third surveillance camera 27 are in the image pickup standby state.

Similarly, at the same time when the number of effective pixels of the second surveillance camera 26 is counted up, the start signal generator 28
Since a generates the third camera start signal D3, this signal D3 is transmitted to the third surveillance camera 2 via the imaging control unit 28b.
7 given. Thereby, the second surveillance camera 26
The imaging operation of the third surveillance camera 27 is started at the same time when the imaging operation of (3) is stopped. Then, similarly to the above, the counter of the imaging controller 28b starts counting the number of effective pixels scanned by the third surveillance camera 27 with the third camera start signal D3 as a reference, and the counted number is the effective pixel number. When it reaches, it will count up. Thereby, the third
The first monitoring camera 25 starts the imaging operation at the same time when the imaging operation of the monitoring camera 27 is stopped. When the third monitoring camera 27 is performing an image capturing operation, both the first monitoring camera 25 and the second monitoring camera 26 are in the image capturing standby state.

Then, each of the surveillance cameras 25 to
The imaging control for 27 is defined as one imaging cycle S, and this imaging cycle S is repeated thereafter. The inspection information on the material 24 to be inspected can be obtained by a series of operations by the surveillance camera imaging control device 30.

In this case, the inspection information in the one image pickup cycle S includes the video signal E1 output from the first surveillance camera 25 which performs the image pickup operation most precedingly according to the first camera start signal D1 and the first image pickup signal E1. 1. Simultaneously with the stop of the image pickup operation of the monitoring camera 25, the video signal E2 output from the second monitor camera 26 which performs the image pickup operation according to the second camera start signal D2, and the stop of the image pickup operation of the second monitor camera 26 at the same time And a video signal E3 output from the third surveillance camera 27 performing an imaging operation according to the third camera start signal D3.

In this way, the video signals E1, E2, E3 extracted in the arrangement order of the monitoring cameras 25 to 27 with a constant time difference.
Are serially connected in time series as shown in FIG. Therefore, the video signals E1, E2, and E3 that are output in parallel with a time difference in parallel from the plurality of monitoring cameras 25 to 27 that obtain inspection information along the width direction of the material to be inspected 24 are apparently converted into serial signals. Is output. In other words, the serial combined video signal E equivalent to being combined as one scanning signal along the width direction of the test material 24 can be obtained.

Then, the serial composite video signal E is supplied to the signal processing unit 22, where the signal processing is performed to detect defect information, and then the determination unit 23 determines whether or not the defect information is a defect. It is something.

As described above, by the image pickup control by the image pickup control device 30, the video signals E1, E2, E3 outputted from the juxtaposed surveillance cameras 25 to 27 are converted into serial data and are sent to the signal processor 22. Can be transferred. Therefore, the number of signal lines from the image pickup control device 30 to the signal processing unit 22 can be reduced, and the signal processing unit 22 processes the serial composite video signal E as it is.
The number of used signal processing units can be reduced without requiring the same number of signal processing units as the number of ~ 27. As a result, the configuration of the signal processing unit 22 and the like can be simplified, and accordingly, the signal processing unit 22 and thus the defect inspection device can be obtained at low cost.

In the first embodiment, the pulse interval A of the camera start signal is set to the surveillance cameras 25-2.
7 is an integer multiple of a value obtained by multiplying the number of effective pixels of the light receiving elements 25a to 27a included in 7 by the number of used monitoring cameras 25 to 27.
Since the number is doubled, it is possible to increase the density of the inspection information obtained by the imaging operation in the monitoring unit 21. However, the present invention is not limited to this, and the integer value of the integral multiple may be set to 2 or more. In such a case, the period in which there is no transfer output of the video signal in the imaging cycle S is the next stage. It is secured before the imaging cycle S (for example, when the integer value is 2, the period corresponding to the next imaging cycle S following the preceding one imaging cycle S in the flowchart of FIG. Therefore, the signal processing unit 22
It is possible to secure a large amount of signal processing time in, and therefore it is suitable when the amount of information of the serial composite video signal E is large.

In the case where the present invention is implemented as an inspection apparatus equipped with the image pickup control apparatus, for example, when the number of monitoring cameras used is large, it is divided into a plurality of camera groups and individually transferred from these camera groups. The same number of signal processing units as the signal processing units for the output serial composite video signals can be provided and implemented.

[0040]

The present invention is embodied in the form described above and has the following effects. According to the invention method of claim 1 and the invention device according to claim 2,
Video signals output from multiple monitoring cameras arranged side by side with a time difference, respectively, are serially connected in time series, and are apparently equivalent to being combined as one scanning signal along the width direction of a moving object. Since the serial transfer is performed in serial, the configuration of the signal processing unit to which the video signal of the surveillance camera is supplied can be simplified, and accordingly, the signal processing unit can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of a defect detection apparatus including an image pickup control apparatus for carrying out an image pickup control method for a surveillance camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the imaging control device of the surveillance camera according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of an imaging control device of a surveillance camera according to a conventional example.

[Explanation of symbols]

 22 ... Signal processing part, 24 ... Inspected material (moving object), 25-27 ... Monitoring camera, 25a-27a ... Light receiving element, 28 ... Camera controller, 28a ... Start signal generating part, 28b ... Imaging control part, 29 ... Sync signal generator, 30 ... Imaging control device.

Claims (2)

[Claims] 1. A plurality of surveillance cameras each comprising a linear CCD camera arranged in parallel with a moving object to be monitored in a direction intersecting the moving direction at a right angle to partially share the image of the moving object. According to a camera start signal generated at regular time intervals based on the same synchronization signal, perform an imaging operation in the order in which the monitoring cameras are arranged, extract the video signals of these cameras, and extract the extracted video signals. An imaging control method for a surveillance camera, which is characterized by outputting in series in series. 2. A synchronization signal generator for generating a synchronization signal at a predetermined cycle and a synchronization signal generator, which are arranged side by side in a direction intersecting a moving object to be monitored at a right angle to the moving object, to partially share the moving object. And a camera controller for controlling the imaging operation of a plurality of surveillance cameras composed of linear CCD cameras that capture images according to the synchronization signal supplied from the synchronization signal generator. A start signal generation unit that generates a camera start signal individually corresponding to each surveillance camera from the synchronization signal at regular time intervals, and gives the camera start signal to each surveillance camera in the order in which they are arranged, An image pickup control unit for performing an image pickup operation, and the image pickup control by this camera controller extracts the monitoring cameras in the order of arrangement. An image pickup control device for a surveillance camera, which outputs a video signal serially and continuously in a time series.