JPH0229085A - Picture input device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has an imaging section, a storage section, and a horizontal transfer section, and performs high-speed frame shifting of signal charges generated when the imaging section is irradiated with light (exposure). Consists of a frame transfer unit COD (charge-coupled device) that transfers signal charge from the imaging unit to the storage unit at high speed using a pulse, and then reads out the signal charge for one horizontal scanning line at a low speed from the storage unit to the horizontal transfer unit using a low-speed vertical transfer pulse. This invention relates to an image input device.

[Conventional technology]

Among such image input devices, an image input device having a high-speed shutter function corresponding to shortening the exposure time in the image pickup section is known as shown in Japanese Patent Application Laid-Open No. 63-54880.

FIG. 3 is a block diagram showing an outline of the configuration of such a conventional image-powered human-powered device with a high-speed shank function.

In the figure, 1 is a frame transfer unit CCD (charge-coupled device), 2 is an imaging unit, 3 is an accumulation unit, 4 is a horizontal transfer unit, 5 is a signal output terminal, 6 is a timing generation unit, 7 is a frame shift pulse, 8 is a vertical transfer pulse, 9 is a horizontal transfer pulse 5, and 10 is a shutter trigger signal.

FIG. 4 is a time chart showing the operation of the apparatus shown in FIG. 3. The circuit operation will be briefly explained with reference to FIGS. 3 and 4.

As shown in FIG. 1, the frame transfer unit COD basically includes an imaging unit 2, a storage unit 3. It consists of a horizontal transfer section 4, a signal output terminal 5, an imaging section 2, a storage section 3. The horizontal transfer section 4 has a frame shift pulse 7, a vertical transfer pulse 8, and a frame shift pulse 7, respectively. A horizontal transfer pulse 9 is applied. Imaging unit 2-1
The signal charge for the horizontal scanning line is 1 of the frame shift pulse 7.
The data is transferred to the storage section 3 by pulse input. Also, the signal charge for one horizontal scanning line in the storage section 3 is equal to 1 of the vertical transfer pulse 8.
The signal is transferred to the horizontal transfer section 4 by pulse input. In the horizontal transfer section 4, 7c is generated by inputting one horizontal transfer pulse 9.
A signal charge corresponding to one pixel is output from the signal output terminal 5 as a video signal.

First, the operation at a time point before t1, which is the timing at which the shutter trigger signal 100 is generated, will be described. Vertical synchronization signal syl! ;Y2 is one field period, but
During one field period (not shown) preceding the vertical synchronization signal syl, signal charges generated by light irradiation (exposure) on the imaging unit 2 are transferred to the storage unit 3 and accumulated by a shift pulse 7 (not shown). The vertical transfer pulses 8 shown (-4 slow vertical transfer pulses indicated by L1 as an example) cause the signal output terminal 5 to be
The image signal is read out as a video signal for one horizontal scan (one line). Of course, the horizontal transfer pulse 9 is continuously output.

Next, the operation after the shutter trigger signal 10 is generated at timing t1 will be described.

For example, when the saw shutter trigger signal 10 generated by the output of a photoelectric switch (not shown) is input to the timing generator 6 at timing t1, in synchronization with the saw shutter trigger signal 10,
The untransferred signal charge generated in the imaging section 2 during the previous one field period (one field period preceding the vertical synchronization signal syl) and remaining without being transferred to the storage section 3 is removed from the imaging section 2. A frame shift pulse 7 for rapid transfer to the storage section 3 is generated from timing t1 to timing t12. At the same time, a high-speed vertical transfer pulse 8 ( ) ( 1 ) is generated to transfer the untransferred signal charges remaining in the storage section 3 up to that point to the horizontal transfer section 4 .

As a result, at timing t2, the imaging section 2 enters a clear state with no signal charge. Then, after the shutter period (L3-t2) corresponding to the exposure time has elapsed, the timing t
3, a frame shift pulse 7 is generated, and the signal charge accumulated in the imaging section 2 during the shutter period (t3-t2) is transferred to the accumulation section 3. At the same time, high-speed vertical transfer pulse? ((H2) is generated, and at that point (timing t
All untransferred signal charges remaining in the accumulation section 3 up to a) are transferred to the horizontal transfer section 4, and further read out from the signal output terminal 5 by the horizontal transfer pulse 9 and discarded.

Then, in the next one field period (one field period following the vertical synchronization signal Sy2), a low-speed vertical transfer pulse 8 (L2) is generated, and the
-t2), the signal charge accumulated in the imaging unit 2 is transferred to the accumulation unit 3.
From the horizontal transfer unit 4--, the image signal is transferred as a video signal for one horizontal scan (one line), and read out from the signal output terminal 5 by the horizontal transfer pulse 9.

[Problem to be solved by the invention]

As explained above, in the conventional electronic shutter type image input device, after the shutter trigger signal 10 is inputted as explained above, the frame shift pulse 7 and the vertical transfer pulse 8 are sent to bring the imaging section 2 into a clear state. After the time (t2-tl) from inputting the shutter trigger signal 10 to clearing the imaging section 2 has elapsed, exposure is started.

Therefore, for example, when a charging switch or the like detects that an object moving by a belt conveyor has arrived at a predetermined position, its output is input to the timing generator 6 as a shutter trigger signal 10, and the electronic shutter is turned off to generate a still image. If the moving speed of the belt conveyor changes when trying to obtain a still image, the position of the obtained still image on the screen may change to the still 1F image 1 on the screen 11 in FIG. 5(a).
2, the position shifts as shown in FIG. 5(b) (X, > Z,), and such position shift must be corrected when automatic inspection is performed using an image processing device. was there.

It is an object of the present invention to solve the above-mentioned problems 1-.
An image input device is provided in which positional deviation of a still image due to the generation period (t2tl) of (vertical transfer pulse 8) does not occur. It's in the second place.

[Means to solve the problem]

In order to solve this problem and achieve the above purpose, the exposure period (t3-t2) starts from the manual input of the shutter trigger signal 10.
The frame shift pulse 7 and the vertical transfer pulse 8 are always generated except for the period until the still image obtained by turning the electronic shutter over a period of time is output as a video signal, and the The imaging unit 2 is kept in a clear state.

[Effect]

The exposure period (t3-
Since the frame shift pulse 7 and the vertical transfer pulse 8 are always generated except for the period until the electronic shank over t2) is turned off and the still image that is incremented by 1 is finished being output as a video signal, the shutter trigger signal Exposure can be started simultaneously with the input of 10, and the position of the still image 12 on the screen 11 is less likely to shift when the moving speed of the belt conveyor changes as in the conventional case.

〔Example〕

FIG. 1 is a time chart showing one embodiment of the present invention.

As shown in FIG. 1, a frame shift pulse 7 and a vertical transfer pulse 8 are always generated before the shutter trigger signal 10 generated by the output of a photoelectric switch is input to the timing generation section 6, and therefore the image pickup section 2 is in a clear state. At timing L4, when the shutter trigger signal IO is input, the frame shift pulse 7 and the vertical transfer pulse 8 are stopped, and a predetermined time (t
5-t4), frame shift pulse 7 and vertical transfer pulse 8 are generated again from timing t5. As a result, the signal charges for one field exposed and accumulated in the imaging unit 2 between timings t, 4 and t5 are transferred to the accumulation unit 3, and after the next vertical synchronization signal sy3, the signal charges are transferred to the storage unit 3 at a low speed. The vertical transfer pulse 8 and the horizontal transfer pulse 9 are outputted from the signal output terminal 5 as a video signal. Furthermore, after all of the video signals have been output, at timing L9, the frame shift pulse 7 and vertical transfer pulse 8 are generated again as shown in FIG. 1, so that the imaging section 2 is always maintained in a clear state.

FIG. 2 is a block diagram showing a specific circuit example of the timing generating section 6 as 6A when the present invention is implemented. In the figure, 21 is an enable signal generation circuit, 22
~24 are frequency dividing counters, 25 is a pulse generator,
It is.

Before the shutter trigger signal 10 is input, the frequency division counters 22 to 24 are all operating, and the pulse generator 2
By frequency-dividing the pulses generated from 5 at the required ratios, a sol/-me shift pulse, a vertical transfer pulse,
It is output as a horizontal transfer pulse.

At timing L4, when the shutter trigger signal 10 is input, at that point the r enable signal generation circuit 21
When the output signal of falls to low, the frequency division counters 22 and 23
stop the operation. Therefore, at this point, the frame shift pulse and vertical transfer pulse stop. Horizontal transfer pulses continue to occur regardless.

Thereafter, the enable signal generating circuit 21 measures time using the pulse train supplied from the pulse generator 25, and detects the arrival of timing t9 after the period (t4-t5) has elapsed and raises the output signal to high. Frequency division counter 2
2 and 23 are restarted.

〔Effect of the invention〕

According to this invention, the frame shift pulse 7 and the vertical transfer pulse 8 are always generated except for the time from when the shutter trigger signal 10 is manually applied until the still image obtained by turning off the electronic shutter is completed as a video signal. Therefore, exposure starts immediately after the shutter trigger signal 10 is input, so that, for example, a photoelectric switch or the like detects that an object moving by a belt conveyor has arrived at a predetermined position, and its output becomes the shank trigger signal. 10 is input to the timing generator 6 and the electronic shutter is turned off to obtain a still image.Even if the moving speed of the belt conveyor changes, the position of the obtained still image 12 on the screen 11 will not shift. (This has the advantage that there is no need to correct positional deviations when performing automatic inspection using an image processing device.

[Brief Description of the Drawings] Fig. 1 is a time chart showing one embodiment of the present invention, Fig. 2 is a time chart showing an embodiment of the present invention;
The figure is a block diagram showing a specific circuit example of the timing generation section when the present invention is implemented, FIG. 3 is a block diagram showing the general configuration of a conventional image input device with a high-speed shutter function, and FIG. FIG. 5 is a time chart showing the operation of the apparatus shown in FIG. 5, and FIG. Explanation of symbols: Frame transfer unit COD (charge-coupled device)
, 2... Imaging section, 3... Accumulation section, 4... Horizontal transfer section, 5... Signal output terminal, 6, 6A... Timing generation section, 7... Frame shift pulse, 8 ...Vertical transfer H/L/S, 9...Horizontal transfer pulse, 10...
Shutter trigger signal, Figure 2 π I Figure 3!

Claims (1)

[Scope of Claims] 1) It has an imaging section, a storage section, and a horizontal transfer section, and after the signal charge generated when the imaging section is irradiated with light is transferred at high speed from the imaging section to the storage section using a high-speed frame shift pulse. In an image input device consisting of a frame transfer type CCD that reads signal charges for one horizontal scanning line at a time from a storage section to a horizontal transfer section at low speed using low-speed vertical transfer pulses, frame shift pulses and vertical transfer pulses are constantly generated at high speed. The signal charges generated when the imaging section is irradiated with light are transferred at high speed from the imaging section to the storage section, and then from the storage section to the horizontal transfer section, read out, and discarded, so that the signal charges in the imaging section are constantly stored. A clearing means is provided to stop the generation of the frame shift pulse and vertical transfer pulse, which are always generated at high speed, for a certain period of time (this is called a shutter period) from the input point of the shutter trigger signal, and to The signal charge generated by irradiation with light is transferred from the imaging section to the storage section at high speed by a high-speed frame shift pulse that is generated immediately after the shutter period has elapsed, and then horizontally transferred from the storage section by a low-speed vertical transfer pulse. 1. An image input device comprising: signal charge reading means for reading signal charges one horizontal scanning line at a time at low speed.