JPH0731249B2 - Imaging system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention detects the arrival of an object moving at high speed with a sensor, and uses a strobe and a CCD camera to take an image with high accuracy. The present invention relates to an image pickup system configured to transfer image pickup data to image input means such as an image processing device.

(Prior art) For example, high speed (5m / S
Generally, when the arrival of a moving object is detected by a photoelectric sensor, the image is captured with high accuracy (± 2 mm) using a strobe and CCD camera, and the image data is transferred to an image processing device, etc. Specifically, the following method is adopted.

(1) As shown in FIG. 4, the photoelectric sensor 1 sends a trigger signal to the image processing device 2,
Is to synchronize with the scanning period of the CCD camera 3 and then send a strobe flashing trigger signal to the strobe controller 4 to turn on the strobe bulb 5.

(2) As shown in FIG. 5, a method of sending a trigger signal from the photoelectric sensor 1 to both the image processing device 2 and the strobe controller 4 to turn on the strobe valve 5.

By the way, in the method (1), the CC
Since the scanning period of the D-camera 3 and the light emission timing of the strobe valve 5 are synchronized, the frame when the strobe valve 5 emits light is surely input to the image processing device 2 by the photoelectric sensor 1. Since the trigger signal is asynchronous with respect to the scanning of the camera, the time difference between the trigger signal and the trigger signal varies by a maximum of 1 frame time (1667 m / Sec in the case of 60 kHz non-interlaced scanning).

This variation is reflected in the position accuracy at the time of image input. For example, when the target object is moving at 5 m / Sec, the maximum error is 5000 mm × 1/60 = 83.3 mm, and where is the target object image input. It becomes indefinite.

On the other hand, in the method of (2), since the trigger signal from the photoelectric sensor 1 directly becomes the trigger signal for strobe light emission,
It is not necessary to consider the problem of position accuracy, but when the trigger signal overlaps with the charge transfer timing of the CCD camera 3, the strobe bulb 5's light emission spans two frames, and normal imaging data is output from the CCD camera 3. It will not be done.

Further, in the image processing apparatus 2, the turning point "when the trigger signal is input for the scanning of the CCD camera 3 to input the image of the next frame" is not always the charge of the CCD camera 3. Since the transfer timing is not the same, a frame different from the frame emitted by the strobe valve 5 may be input as an image.

FIG. 6 shows the waveform of each signal in the conventional imaging system.

In the figure, VD is a vertical synchronizing signal of the CCD camera 3, and HD is a horizontal synchronizing signal of the CCD camera 3. One cycle (1H) of the horizontal sync signal HD is 63.56 μS, and one cycle of the vertical sync signal VD is 262H.

Also, VIDEO is the image data output from the CCD camera 3, SG
Is the charge transfer timing of the CCD camera 3.

For example, when the turning point in the image processing device is the rising position of the vertical synchronizing signal VD from the CCD camera 3, the trigger signal is the rising position of the vertical synchronizing signal VD and CC.
D When the charge transfer timing SG of the camera 3 occurs between the trailing position and the trailing position of the charge transfer timing SG, the next frame is image-processed even though the imaging data when the strobe valve 5 emits light is included in the next frame. It is input to the device 2.

(Problems to be Solved by the Invention) As described above, according to the conventional imaging system, the positional accuracy of the position at the time of imaging becomes low, the frame in which the flash bulb emits light is not input, or abnormal imaging data is CC
There was a problem that it might be output from the D camera.

The present invention has been made under such circumstances, and the positional accuracy at the time of image pickup is high, the frame in which the strobe bulb emits light can be reliably input, and abnormal image pickup data is generated by the CCD.
It is intended to provide an imaging system that is not output from a camera.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve this object, the present invention detects the arrival of a moving object by a predetermined detection means, and a flash signal is generated by a trigger signal output from the detection means. An image pickup system for picking up an image of the object by an image pickup unit having an image pickup period and a transfer period while operating the image pickup unit and the image input unit,
The holding period of the trigger signal is set in association with the scanning period of the image pickup unit and the transfer period of the imaged data, and the trigger signal generated outside the period is immediately output to the image input unit and generated within this period. The trigger signal is delayed until the end of this period and output to the image input unit, and the trigger signal output to the image input unit is further delayed for a certain period and output to the flash unit. is there.

(Operation) In the image pickup system of the present invention, the hold period of the trigger signal is set in association with the scanning period of the image pickup means and the transfer period of image pickup data.

Then, the trigger signal generated outside of this period is immediately output to the image input unit, and the trigger signal generated within this period is delayed until the end of this period and then output to the image input unit.

Further, the trigger signal output to the image output signal is further delayed for a certain period and output to the flash unit.

As a result, the flashing means operates while avoiding the image data transfer period of the imaging means, and the frame emitted by the flashing means is surely input to the image processing means.

(Example) Hereinafter, the detail of the Example of this invention is described based on drawing.

FIG. 1 is a block diagram showing a configuration of an embodiment of an image pickup system of the present invention, and portions common to FIGS. 4 and 5 are designated by common reference numerals.

In the figure, 1 is a photoelectric sensor for detecting the arrival of an object,
Reference numeral 2 is an image processing device for inputting image pickup data from the CCD camera 3 and performing processing such as pattern matching. Reference numeral 4 is a strobe controller for causing a strobe valve 5 to emit light.

Reference numeral 6 is a delay circuit interposed between the photoelectric sensor 1, the image processing device 2 and the flash controller 4.

The delay circuit 6 has a function of delaying a trigger signal output from the photoelectric sensor 1 as described later and outputting it as a trigger signal to the image processing apparatus 2 and the flash controller 4.

FIG. 2 is a timing chart showing the timing relationship of each signal in this embodiment.

In the figure, VD is a vertical synchronizing signal of the CCD camera 3, and HD is a horizontal synchronizing signal of the CCD camera 3.

In this embodiment, one cycle (1H) of the horizontal sync signal HD
Is 63.56 μS, and one cycle of the vertical synchronizing signal VD is 262H.

Also, VIDEO is the image data output from the CCD camera 3, SG
Is the charge transfer timing of CCD camera 3, TRIGGER INHIBI
T is a signal that holds the trigger signal from the photoelectric sensor 1 for a certain period as described later.

The trigger signal is from the photoelectric sensor 1 to the delay circuit 6
Is a trigger signal output from the delay circuit 6 to the image processing apparatus 2, and the trigger is a trigger signal output from the delay circuit 6 to the strobe controller 4.

The delay circuit 6 of this embodiment inputs the trigger signal, the vertical synchronizing signal VD and the horizontal synchronizing signal HD from the photoelectric sensor 1, outputs the trigger signal to the image processing device 2, and outputs the trigger signal to the strobe controller 4. Output the trigger signal.

In the delay circuit 6, in the vicinity of the turning point in the image processing apparatus 2 (previously, when the trigger signal is input to the scanning of the CCD camera 3 can the image input of the next frame be performed), here Then, at a position delayed by time t ₁ from the falling edge of the vertical synchronization signal VD, with a width t ₂ that is sufficiently smaller than the width of the charge transfer timing SG.
Generate the TRIGGER INHIBIT signal.

Then, the trigger signal to the image processing device 2 is in this section t ₂
If it is input in other than, the trigger signal is immediately output, and if it is input within this section t ₂ , the trigger signal is output immediately after the end of this section.

On the other hand, the trigger signal is always output to the strobe controller 4 when it is delayed by the time t ₃ from the trigger signal. This time t ₃ is set equal to the time difference between the turning point of the image processing apparatus 2 and the charge transfer timing SG of the CCD camera 3.

FIG. 3 is a block diagram showing the configuration of the delay circuit 6 in this embodiment.

In the figure, 6a is a t ₁ setting circuit such as a DIP switch for setting the time t ₁ , 6b is a horizontal synchronizing signal HD and a vertical synchronizing signal
T ₁ counter for counting VD, 6c for t ₂ setting circuit such as DIP switch for setting time t ₂ , 6d for horizontal synchronizing signal HD
And a t ₂ counter that counts the vertical synchronizing signal VD. In this embodiment, the pulse output from the t ₂ counter 6d becomes the TRIGGER INHIBIT signal.

Reference numeral 6e is an arithmetic circuit that inputs the TRIGGER INHIBIT signal and the trigger signal from the photoelectric sensor 1 for arithmetic operation and outputs the trigger signal obtained by delaying the trigger signal as necessary.

Further, 6f is a t ₃ setting circuit such as a DIP switch for setting the time t ₃ , and 6g is a t ₃ counter for counting the horizontal synchronizing signal HD and the vertical synchronizing signal VD. In the present embodiment, this t ₃
The pulse output from the counter 6g becomes the trigger signal.

In this embodiment, t ₁ is 0 to 262H and t ₂ is 0 to 20H.
H, _{t 3} is variable in the range of 0～20H.

In this embodiment, since the delay circuit 6 is provided between the photoelectric sensor 1, the image processing device 2 and the flash controller 4, the trigger signal is always output when the trigger signal is output before the turning point. It is output before the charge transfer timing of.

On the other hand, when the trigger signal is output after the turning point, the trigger signal must be the CCD camera 3
Since the image is output after the charge transfer timing, the image processing device 2 can surely input the image of the frame emitted by the strobe.

Then, since the interval in which the trigger signal is never output is set near the charge transfer timing with the same width as t ₂ , the strobe light emission does not span two frames. Therefore, there is no possibility that abnormal imaging data will be output.

Further, in this embodiment, the trigger signal is t ₃ of the trigger signal.
Since the maximum delay is t ₂ hours after the time, the positional accuracy of the image pickup is extremely high.

For example, t ₂ is 3H (≈190.7 μSec) and t ₃ is 12H (≈762.7).
μSec), the moving speed v of the object is 5m / Sec
In that case, if the photoelectric sensor 1 is placed in front of the image input position by (t ₃ + 1/2 × t ₂ ) × v = (762.7 μSec + 1/2 × 190.7 μSec) × 5 m / Sec ≈4.3 mm, Image input can be performed with a positional accuracy of ± (1/2 × t ₂ × v) = ± (1/2 × 190.7 μSec × 5 m / Sec) = ± 0.5 mm.

In this embodiment, as the CCD camera 3, a so-called two-dimensional scanning type image sensor that scans the image of the object in frame units is used, but the present invention scans the image of the object in line units. The same can be applied when a one-dimensional scanning type image sensor is used.

Further, in this embodiment, the photoelectric sensor 1 is used as the sensor for detecting the arrival of the object, but other non-contact type sensor can be used.

Furthermore, although the image pickup data of the CCD camera 3 is input to the image processing apparatus 2 in this embodiment, if the input timing of the image pickup data can be controlled, the image pickup data may be input to another apparatus. Good.

[Advantages of the Invention] As described above, in the imaging system of the present invention, the trigger signal from the sensor that detects the arrival of the object is delayed after setting a predetermined holding section, and then the image input unit and the flash unit. Since the image is output, the position accuracy at the time of image input is high, the frame generated by the flash unit can be surely input, and abnormal imaging data is not generated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of an embodiment of an image pickup system of the present invention, FIG. 2 is a timing chart showing the relationship of each signal in the embodiment, and FIG. Block diagrams showing the configuration of the delay circuit in the example, FIGS. 4 and 5
FIG. 6 is a diagram showing the configuration of a conventional image pickup system, and FIG. 6 is a timing chart showing the relationship of each signal in the conventional image pickup system. 1 ... Photoelectric sensor, 2 ... Image processing device, 3 ... CCD camera, 4 ... Strobe controller, 5 ... Strobe valve, 6 ... Delay circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H04N 7/18 B (56) References JP 63-21566 (JP, A) JP 60 -39581 (JP, A) JP-A-58-168942 (JP, A)

Claims (1)

[Claims] 1. An image pickup means having an image pickup period and a transfer period while operating the flashing means and the image input means by detecting the arrival of a moving object by a predetermined detecting means and operating a flash signal by the trigger signal output from the detecting means. In an image pickup system for picking up an image of the object, a holding period of the trigger signal is set in association with a scanning period of the image pickup unit and a transfer period of image pickup data, and the trigger signal generated outside this period is immediately input to the image input. Means, and the trigger signal generated within this period is delayed until the end of this period and is output to the image input unit, and the trigger signal output to the image input unit is further delayed for a certain period to obtain the trigger signal. An imaging system characterized by outputting to a flash unit.