JPH09154068A - Solid-state image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-state image pickup device with which high-speed shutter higher than 1/100000sec is enabled. SOLUTION: Based on the front edge of trigger pulse supplied from the outside, a subsignal generator 9 supplies an external vertical synchronizing signal VDout and an external horizontal synchronizing signal HDout to a timing generator 12. After the external vertical synchronizing signal VDout is supplied and the prescribed number of external horizontal synchronizing signal HDout are counted, the timing generator 12 supplies a read pulse to a CCD driving circuit 15. On the other hand, a shutter preparation circuit 14 superimposes a last shutter pulse based on the rear edge of trigger pulse onto a shutter pulse from the subsignal generator 9 and supplies that shutter pulse to the CCD driving circuit 15. Based on the shutter pulse and read pulse supplied to the CCD driving circuit 15, a CCD image sensor 17 outputs an image pickup signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device suitable for use mainly in an industrial camera device for picking up an image of an object moving at high speed, and more particularly to a solid-state image pickup device capable of high-speed shutter.

[0002]

2. Description of the Related Art The applicant of the present invention uses an iris mechanism by controlling the charge storage time of a field storage type solid-state image pickup device (CCD image sensor) in the specification and drawings of JP-A-6-86180. Instead, it proposes a solid-state imaging device that adjusts exposure and enables a high-speed shutter.

In this solid-state image pickup device, a read pulse for reading out the accumulated charge is supplied to this solid-state image pickup device after the supply of the shutter pulse for sweeping away the charge accumulated in the solid-state image pickup device is stopped. The charge storage time of the solid-state imaging device is controlled by controlling the timing of stopping the supply of the shutter pulse.

In the above solid-state image pickup device, as shown in FIG. 3, for example, an object 102 moving on a moving path 101 is detected by a position detection circuit 103, and a trigger from the outside, which is a position detection signal from the position detection circuit 103, is detected. It can be used as an industrial solid-state imaging device for imaging the object 102 in synchronization with a pulse.

Specifically, this solid-state image pickup device adjusts the phases of an external vertical synchronizing signal and an external horizontal synchronizing signal supplied from the outside and outputs them as an internal vertical synchronizing signal and an internal horizontal synchronizing signal, respectively. Pulse (f
_{When a} trigger pulse is supplied from the position detection circuit 103 and the signal generator 108 that outputs a pulse (f _CK / 4) with a cycle four times that of _CK ), the internal horizontal synchronization signal of the signal generator 108 is output. A modulated HD creation circuit 110 is provided which modulates the phase according to a designated shutter speed to form a modulated horizontal synchronizing signal, and delays and outputs the modulated horizontal synchronizing signal for a fixed time.

The solid-state image pickup device also detects and outputs a phase difference between an external horizontal synchronizing signal externally supplied via the signal generator 108 and an internal horizontal synchronizing signal supplied from the signal generator 108. And a low-pass filter that forms and outputs a control DC voltage from the phase comparison output from the comparator 113 and the comparator 113 (hereinafter,
LPF 114, and a voltage-controlled oscillator (hereinafter referred to as VC) that oscillates according to the control DC voltage from the LPF 114.
115).

Further, this solid-state image pickup device supplies a clock pulse (f _CK ) to the signal generator 108, and at the same time, an internal vertical synchronizing signal and a modulated horizontal synchronizing signal (or an internal horizontal synchronizing signal) supplied from the signal generator 108. A timing generator 111 that outputs a read pulse or the like for reading the charge accumulated in the CCD image sensor 105 in response thereto, and a CCD drive circuit 112 that drives the CCD image sensor 105 in response to the pulse from the timing generator 111 are provided.

The solid-state image pickup device generates a shutter pulse and supplies it to the CCD drive circuit 112. On the other hand, when a trigger pulse is supplied, the shutter generation circuit 11 stops the generation of the shutter pulse for one vertical blanking period, for example.
6 and an image pickup signal processing circuit 117 which performs signal processing such as adding a synchronization signal to the image pickup signal which is the electric charge read from the CCD image sensor 105 and supplies the signal to an analyzer for image analysis or the like.

In the solid-state image pickup device constructed as described above,
For example, as shown in FIG. 3, for example, an object 1 moving at high speed
When it is desired to analyze the moving state of 02, the moving path 101 is controlled so as to move the object 102 at high speed.

The position detection circuit 103 outputs a trigger pulse when it detects that the object 102 moving on the moving path 101 is positioned in front of the CCD image sensor 105.
The trigger pulse is generated by the signal generator 108, the modulation HD creating circuit 110, the timing generator 111.
And the shutter generation circuit 116.

On the other hand, the comparator 113 detects the phase difference between the external horizontal synchronizing signal supplied from the outside through the signal generator 108 and the internal horizontal synchronizing signal supplied from the signal generator 108, and detects this phase difference.
To supply. The LPF 114 forms a control DC voltage from the phase comparison output from the comparator 113 and outputs it to the VCO1.
15 The VCO 115 is responsive to the control DC voltage from the LPF 114 to generate the timing generator 11
A clock pulse (2f _CK ) having a frequency twice that of the clock pulse (f _CK ) supplied from 1 to the signal generator 108 is formed, and this is supplied to the timing generator 111.

The timing generator 111 latches the internal vertical synchronizing signal from the signal generator 108 with a clock pulse having a doubled frequency, forms an internal vertical synchronizing signal as shown in FIG. 3, for example, and drives this CCD. CCD image sensor 1 via circuit 112
05.

The shutter forming circuit 116 forms and outputs a shutter pulse until the trigger pulse is supplied, and supplies this shutter pulse to the CCD image sensor 105 via the CCD drive circuit 112.

The CCD image sensor 105 does not output an image pickup signal because the accumulated charge is swept to the overflow drain every time the shutter pulse is supplied.

However, when the trigger pulse is supplied to the shutter producing circuit 116, the shutter pulse is not produced during the vertical blanking period, so that the CCD image sensor 10 is operated.
Reference numeral 5 accumulates the effective charge of the imaging light emitted through the imaging lens 104.

On the other hand, when the trigger pulse is supplied to the signal generator 108, the timing generator 1
A pulse (f _CK / 4) having a quadruple cycle is formed from the clock pulse (f _CK ) supplied from 11, and this is supplied to the modulation HD creation circuit 110.

When a pulse having a quadruple cycle is supplied, the modulation HD producing circuit 110 produces, for example, nine high frequency signals, superimposes these high frequency signals and the internal horizontal synchronizing signal from the signal generator 108, and The superimposed signal is output as a modulated horizontal synchronizing signal.

The timing generator 111 has a modulation H
After counting the modulated horizontal synchronizing signal (or internal horizontal synchronizing signal) from the D creating circuit 110 for 9 times, the clock pulse is counted for several hundreds to form a read pulse, and this is read by the CCD.
It is supplied to the drive circuit 112.

The CCD drive circuit 112 reads the effective charge accumulated in the CCD image sensor 105 in response to the read pulse.
Drive. The charges read from the CCD image sensor 105 are supplied to the image pickup signal processing circuit 117 as an image pickup signal.

The image pickup signal processing circuit 117 performs signal processing such as adding a synchronizing signal to the image pickup signal, and supplies this to the monitor device of the analyzer or the like via the output terminal 118.

As a result, an image of the object 102 moving on the moving path 101 is displayed on the monitor device, and the object can be analyzed.

Here, in the above solid-state image pickup device, the modulation H
Since the frequency of the modulated horizontal synchronizing signal formed by the D creating circuit 110 can be varied, a desired shutter speed can be achieved.

Specifically, the frequency of the modulated horizontal synchronizing signal,
Alternatively, the shutter speed can be controlled by controlling the length of a certain period of time until a pulse having a quadruple cycle is generated.

That is, assuming that the delay time until the pulse of 4 times period is generated is 1H (64 μs), the period of the pulse of 4 times period is 70 ns, and the time for counting several hundreds of clock pulses is 42 μs, the shutter speed T1 is , T1 = 64 × 10 ⁻⁶ + 0.07 × 10 ⁻⁶ × 8 + 42 × 10 ⁻⁶ = 106.56 × 10 ⁻⁶ seconds ≈1 / 9400 seconds.

When the internal vertical synchronizing signal is latched by the clock pulse (2f _CK ) having the double frequency in the timing generator 111 as described above, the time until the pulse of the quadruple cycle is generated is 1 / 2H. Therefore, the shutter speed T2 can be set to T2 = 32 × 10 ⁻⁶ + 0.07 × 10 ⁻⁶ × 8 + 42 × 10 ⁻⁶ = 74.56 × 10 ⁻⁶ seconds ≈1 / 13000 seconds, A high speed shutter can be enabled.

Therefore, an image of an object moving at a high speed can be clearly and easily captured, which contributes to industrial use.

[0027]

By the way, such a solid-state image pickup device for picking up an image of a moving object at a high speed is mainly used for industrial purposes. Therefore, for example, 1/100000.
It may be necessary to take an image with a high-speed shutter for more than a second.

However, as described above, the solid-state image pickup device is capable of a high-speed shutter up to 1/13000 seconds at most, and a high-speed shutter of 1/10000000 seconds or longer is impossible.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a solid-state image pickup device capable of a high-speed shutter of 1/100000 second or more.

[0030]

In order to solve the above-mentioned problems, a solid-state image pickup device according to the present invention comprises a sync signal generating means for generating a horizontal signal and a sync signal, and a trigger pulse supplied from the outside. A leading edge pulse synchronized with an edge, a trigger detection means for outputting a trailing edge pulse synchronized with the trailing edge of the trigger pulse, and an external vertical synchronization signal synchronized with the leading edge pulse from the trigger detection means, An external synchronizing means for generating a high-speed horizontal synchronizing signal for a predetermined period from the timing of the leading edge pulse, and a shutter pulse for each horizontal blanking period of the horizontal synchronizing signal from the synchronizing signal generating means except for the predetermined period. At the same time, the shutter pulse generating means for generating a shutter pulse at the timing of the trailing edge pulse from the trigger detecting means in the predetermined period, and the external pulse generating means. The signal from the means is obtained by photoelectrically converting the light incident from the subject, and the read pulse generating means for generating a read pulse after a lapse of a predetermined number of the high-speed horizontal synchronizing signals from the timing of the Weiwu vertical synchronizing signal. The accumulated charge is accumulated, and the accumulated charge is swept away every time the shutter pulse is supplied from the shutter pulse generation means, and the read pulse is supplied from the read pulse generation means, and then the sync signal generation means is supplied. And a solid-state image pickup device for reading out an image pickup signal based on charges accumulated in synchronization with the horizontal synchronizing signal.

As a result, the solid-state image pickup device can start the accumulation of effective charges based on the trailing edge of the trigger pulse supplied from the outside, and can supply the read pulse generating means with the high-speed horizontal synchronizing signal. By doing so, the reading of the effective charge can be speeded up.

Therefore, according to the above solid-state image pickup device,
By adjusting the width of the trigger pulse from the outside and setting the frequency of the high-speed horizontal synchronizing signal high, the effective charge accumulation period, that is, the shutter period is, for example, 1/100.
A high-speed shutter of 000 seconds or more is possible.

[0033]

Embodiments of a solid-state imaging device according to the present invention will be described below with reference to the drawings.

The solid-state image pickup device according to the present invention uses, for example, a normal mode for picking up an image of a normal subject and a position detection signal from the position detection circuit 8 for an object 2 moving on a moving path 1 as shown in FIG. There is a high-speed mode in which an image is picked up in synchronization with a trigger pulse from the outside, and in the high-speed mode, it can be used as an industrial image pickup device. Note that this solid-state imaging device, as shown in FIG.
11 is switched to the H terminal and is already set to the high speed mode.

The solid-state image pickup device, as shown in FIG. 1, for example, includes a signal generator 13 which is a synchronizing signal generating means for generating a horizontal signal and a synchronizing signal, and a leading edge pulse and a trailing edge pulse from the supplied trigger pulse. An external vertical synchronizing signal is generated based on the leading edge pulse from the trigger detecting means and the monostable circuit 7 and the monostable circuit 8 which are the trigger detecting means to output, and a high speed is obtained for a predetermined period from the timing of the leading edge pulse. A sub signal generator 9 which is an external synchronizing means for generating a horizontal synchronizing signal (hereinafter referred to as an external horizontal synchronizing signal), and a read pulse is generated based on the external vertical synchronizing signal and the external horizontal synchronizing signal from the external synchronizing means. And a timing generator 12 which is a read pulse generating means, and generates a shutter pulse except for the predetermined period. Together, the above-mentioned sub-signal generator 9 and shutter creating circuit 14 which are shutter pulse generating means for generating a shutter pulse at the timing of the trailing edge pulse in the above-described predetermined period, and the accumulated charge is swept every time the shutter pulse is supplied. And a CCD image sensor 17 which is a solid-state image pickup device which outputs an image pickup signal corresponding to the accumulated charges when the read pulse is supplied.

Specifically, the signal generator 13
Generates an internal vertical synchronizing signal VD and an internal horizontal synchronizing signal HD in response to a clock pulse supplied via the timing generator 12.

The monostable circuit 7 detects the leading edge of the trigger synchronization signal supplied from the outside, and supplies the leading edge pulse to the sub signal generator 9. The monostable circuit 8 detects the trailing edge of the trigger synchronization signal and supplies the trailing edge pulse to the shutter creating circuit 14.

The sub signal generator 9 synchronizes with the leading edge pulse from the monostable circuit 7 and outputs the external vertical synchronizing signal VD.
out, and during the vertical blanking period from the time the leading edge pulse was supplied, the external horizontal sync signal HDou
t is supplied to the timing generator 12 via the switches 10 and 11. The vertical blanking period is determined by the sub signal generator 9 counting the pulses of the internal horizontal synchronizing signal HD supplied from the signal generator 13.

Further, the sub signal generator 9 is adapted to supply the shutter pulse supplied from the timing generator 12 to the shutter creating circuit 14 except during the vertical blanking period.

The timing generator 12 counts a predetermined number of pulses of the external horizontal synchronizing signal HDout from the time the external vertical synchronizing signal VDout is supplied from the sub signal generator 9, and counts several hundreds of clock pulses generated by the clock setting circuit 12a. After that, a read pulse is output.

Further, the timing generator 12 outputs the shutter pulse for sweeping away unnecessary electric charges accumulated in the CCD image sensor 17 for each horizontal blanking period of the internal horizontal synchronizing signal HD supplied from the signal generator 13. It is supplied to the sub signal generator 9.

As shown in FIG. 2, the shutter creating circuit 14 generates a shutter pulse (hereinafter referred to as a last shutter pulse) in synchronization with the trailing edge pulse from the monostable circuit 8 and outputs this last shutter pulse as a sub signal. It superimposes on the shutter pulse from the generator 9, and supplies this superposed shutter pulse to the CCD drive circuit 15. The last shutter pulse is for discarding unnecessary charges accumulated in the CCD image sensor 17 immediately before the start of the effective charge accumulation period.

Based on the shutter pulse supplied from the shutter creating circuit 14 and the read pulse supplied from the timing generator 12, the CCD drive circuit 15 performs CC
The D image sensor 17 is driven. That is, the CCD image sensor 17 discards unnecessary charges and starts accumulation of effective charges when a shutter pulse is supplied via the CCD drive circuit 15, and then the timing generator 12 is started.
When the read pulse is supplied from the device, the image pickup signal corresponding to the effective accumulated charge is output.

Further, the above solid-state image pickup device has a correlated double sampling circuit (hereinafter referred to as a CDS circuit) for reducing random noise of the image pickup signal from the CCD image sensor 17.
18 and a process circuit 7 that performs so-called process processing such as white clip and knee processing for dynamic range compression, blanking insertion, gamma correction, and black clip on the image pickup signal supplied from the CDS circuit 18.

The solid-state image pickup device configured as described above is
The object 2 moving along the moving path 1 is the CCD image sensor 17
When the sub-signal generator 9 supplies the timing generator 12 with the external horizontal synchronizing signal HDout and the external vertical synchronizing signal VDout which are synchronized with the trigger pulse obtained by detecting that the vehicle is positioned in front of the position detecting circuit 3. Perform the imaging operation as shown in 2 and CC
The D image sensor 17 captures an image of an object moving at high speed on the moving path 1.

That is, when the position detecting circuit 3 detects that the object 2 moving on the moving path 1 is positioned in front of the CCD image sensor 17, the trigger pulse shown in FIG.
Output to the outside through the terminal 4. When the external synchronization signal generator 5 provided externally supplies the trigger pulse, it outputs the trigger synchronization signal in synchronization with this. In addition,
The external synchronization signal generator 5 can adjust the width of the supplied trigger pulse to a desired value.

When a trigger synchronizing signal from the outside is supplied from the terminal 6 to the inside, the monostable circuit 7 supplies a leading edge pulse to the sub signal generator 9, and the monostable circuit 8 creates a trailing edge pulse as a shutter. Supply to the circuit 14.

When the leading edge pulse is supplied, the sub signal generator 9 supplies the external vertical synchronizing signal VDout and the external horizontal synchronizing signal HDout to the timing generator 12, as shown in FIG.

When the external vertical synchronizing signal VDout and the external horizontal synchronizing signal HDout are supplied from the sub signal generator 9, the timing generator 12 outputs the external horizontal synchronizing signal HDout from the time when the external vertical synchronizing signal VDout is supplied, for example. After counting 9 and counting hundreds of clock pulses, a read pulse is supplied to the CCD drive circuit 15. Also, the timing generator 12
A shutter pulse is supplied to the sub signal generator 9 every horizontal scanning period.

When the shutter pulse is supplied from the timing generator 12, the sub signal generator 9 supplies the shutter pulse to the shutter creating circuit 14 except for the vertical blanking period.

The shutter creating circuit 14 superimposes the last shutter pulse based on the trailing edge pulse from the monostable circuit 8 on the shutter pulse from the sub signal generator 9,
The superimposed shutter pulse is supplied to the CCD drive circuit 15.

The CCD drive circuit 15 discards the unnecessary charges accumulated in the CCD image sensor 17 based on the supplied superimposing shutter pulse. Then, the CCD image sensor 17 outputs an image pickup signal according to the effective charge when the read pulse is supplied.

That is, the CCD image sensor 17 is
2 is driven by a CCD drive circuit 15 which operates in response to a read pulse generated by the timing generator 12 in synchronization with the external horizontal synchronizing signal HDout and the external vertical synchronizing signal VDout generated by the sub signal generator 9. As shown in FIG. As described above, the image pickup operation is performed by the high-speed shutter with the shutter period T from the falling timing Ta of the shutter pulse synchronized with the trailing edge of the trigger synchronization signal to the rising timing Tb of the read pulse.

In the shutter period T, the frequency of the external horizontal synchronizing signal HDout is set to a desired value in advance to accelerate the generation of the read pulse, and the position of the trailing edge of the trigger pulse supplied from the outside is set. It can be shortened easily by making it slow. Further, since the external horizontal synchronizing signal HDout has a higher frequency than the internal horizontal synchronizing signal HD which is a normal frequency, the timing generator 12 finishes counting earlier than counting the internal horizontal synchronizing signal HD, The read pulse can be output quickly. As a result, the solid-state imaging device can perform a high speed shutter of 1/100000 second.

As a result, the object 2 moving along the moving path 1
Is displayed on, for example, a monitor device (not shown), and the user can analyze this object.

Further, the solid-state image pickup device generates the external vertical synchronizing signal VDout and the external horizontal synchronizing signal HDout according to the trigger pulse regardless of the timing of the internal vertical synchronizing signal VD and the internal horizontal synchronizing signal HD. ,
Since the read pulse is generated on the basis of these, even if the above trigger pulse is generated at random timing, the exposure time, that is, the effective charge accumulation period T can be made constant, resulting in unevenness. The missing image can be displayed on the monitor device.

Furthermore, since the time for which the read pulse is generated is uniquely determined by the external horizontal synchronizing signal HDout and the internal clock, the user is required to use the external horizontal synchronizing signal HDou.
By fixing the frequency of t to a desired value in advance, the exposure time can be set to a desired time.

In the above solid-state image pickup device, the shutter period can be widened by changing the width of the trigger pulse supplied from the outside, and the shutter period can be set to 1/1000 seconds, for example. is there.

Thus, the technical idea according to the present invention is
In a solid-state imaging device that performs imaging in synchronization with a randomly supplied trigger pulse, a shutter period is started in synchronization with a trailing edge of a trigger pulse, and a horizontal synchronizing signal is counted by a predetermined number and a read pulse is output. By supplying an external horizontal synchronizing signal having a higher frequency than the horizontal synchronizing signal having the normal frequency to the timing generator, the counting operation of the timing generator is terminated early to operate the high speed shutter.

Therefore, the technical idea is not limited to the above-described embodiments, and it goes without saying that the present invention can be variously modified without departing from the technical idea. is there.

[0061]

According to the solid-state image pickup device of the present invention, the accumulation of effective charges can be started based on the trailing edge of a trigger pulse from the outside, and a high frequency external horizontal synchronizing signal is supplied to the read pulse generating means. Can be supplied to speed up the reading of the effective accumulated charge, so that, for example, 1/100
Imaging with a high-speed shutter of 000 seconds or more is possible.

Further, this solid-state image pickup device generates an external vertical synchronizing signal and an external horizontal synchronizing signal for the trigger pulse regardless of the vertical synchronizing signal and the horizontal synchronizing signal,
Since the read pulse is generated on the basis of these, even if the trigger pulse is generated at random timing, the exposure time, that is, the effective charge accumulation period T can be made constant, and there is no unevenness. The image can be displayed on the monitor device.

Further, in the above solid-state image pickup device, the time at which the read pulse is generated is uniquely determined by the external horizontal synchronizing signal and the internal clock, so the user fixes the frequency of the external horizontal synchronizing signal to a desired value in advance. By
The exposure time can be set to a desired time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a specific configuration of a solid-state imaging device according to the present invention.

FIG. 2 is a timing chart illustrating an operating state of the solid-state imaging device.

FIG. 3 is a block diagram showing a specific configuration of a conventional solid-state imaging device.

[Explanation of symbols]

 7 Monostable Circuit 8 Monostable Circuit 9 Sub Signal Generator 12 Timing Generator 13 Signal Generator 14 Shutter Creation Circuit 17 CCD Image Sensor

Claims (2)

[Claims] 1. A synchronizing signal generating means for generating a horizontal signal and a synchronizing signal, a leading edge pulse synchronized with a leading edge of a trigger pulse supplied from the outside, and a trailing edge pulse synchronized with a trailing edge of the trigger pulse. Trigger detecting means for outputting, and an external synchronizing means for generating an external vertical synchronizing signal synchronized with the leading edge pulse from the trigger detecting means, and for generating a high-speed horizontal synchronizing signal for a predetermined period from the timing of the leading edge pulse, A shutter pulse is generated for each horizontal blanking period of the horizontal synchronizing signal from the synchronizing signal generating means except the predetermined period, and a shutter pulse is generated at the timing of the trailing edge pulse from the trigger detecting means in the predetermined period. Shutter pulse generating means, and the high-speed horizontal synchronizing signal from the timing of the external vertical synchronizing signal from the external synchronizing means. A read pulse generation means for generating a read pulse after a lapse of a predetermined number of times, and charges accumulated by photoelectrically converting the light incident from the subject are accumulated, and the shutter pulse is supplied from the shutter pulse generation means. Each time the charge is swept away, the read pulse is supplied from the read pulse generation means, and then the image pickup signal based on the charge accumulated in synchronization with the horizontal sync signal from the sync signal generation means is read out. A solid-state image pickup device, comprising: 2. The solid-state imaging device according to claim 1, further comprising pulse width adjusting means for adjusting the pulse width of the trigger pulse to a desired value and supplying the trigger pulse to the trigger detecting means.