JPS58103274A - Driving system of solid-state image pickup device - Google Patents

Abstract

PURPOSE:To shorten the exposure time and at the same time to obtain a static picture of high quality, by supplying the transfer pulse to a solid-state image pickup element before a period of acquisition of the picture signal and getting rid of the unnecessary picture information obtained by the light which is produced before said acquisition period of the picture signal. CONSTITUTION:It is supposed that the number of vertical bits at a photoelectric conveting part 15A and a vertical signal transfer part 15B of an image pickup element 15 is equal to the number of transfer pulses PTRB. Thus the electric charge remains only at the part 15B with some transfer pulses PTRA and PTRB. As a result, the electric charge residual at the part 15B is read out to cause a slight signals to the video output signal 174. At the same time, the component of the signal produced for read-out of the electric charge is increased by the pulse of the signal 71B4 of high density obtained after storage PC1. However, the quantity of electric charge corresponding only to a subject is stored at the part 15A with no smear for the pulse width time TC1 of the pulse PC1 in a period PD3. This electric charge is read out in the next period.

Description

[Detailed Description of the Invention] Regarding the driving method of the image sensor, a solid-state image sensor that can appropriately control the exit time (light accumulation time) without generating an undesirable signal, especially for a moving subject. This relates to the driving method of the element.

Instead of still cameras using conventional photographic film,
Research has been conducted on recording still images electrically.1 For example, images from a television camera using a solid-state image sensor can be frozen using electronic means such as magnetic disks or magnetic bubble devices. -An electronic still camera that reproduces images as a still image is introduced as a still camera◎
A static camera using such a solid-state image sensor and a recording element such as a magnetic bubble records one frame of the subject image signal captured by the solid-state image sensor on the recording element. fj14 / Shown in the diagram / In the diagram / Light from the subject (not shown) is filtered through the lens // and aperture / J
The solid-state image sensor 15 is irradiated with the light through the solid-state image sensor 15.

Here, the solid-state image sensor/S is a CCD, and this CCD
On the CD, an image of the object is formed as an accumulated charge for the required time.The image is taken out from this image sensor and the analog output signal Q/7 is sent to an analog-to-digital converter (hereinafter referred to as A/
(referred to as a D converter)/9 converts it into a digital signal 46 No. 1, and supplies four response speeds corresponding to this digital signal 2/ to a digital field memory n. In response to the recording system 33 from the controller 3/, signals for l fields of the digital signal 2/ are stored in the field memory n.

The information pledged in this way is transmitted to the playback control signal j3.
In response to this, the data is successively read from the field memory B, the successive signal 3S is supplied to the recording element n, data for one field is sequentially written, and the filling operation is completed.

The writing speed in this case does not need to be particularly related to the standard television system. When the dusting is completed, information as a still image of the subject is recorded in the recording element n. Here, a non-volatile type such as a magnetic bubble memory, a magnetic disk, or a magnetic tape is used as the recording element n, and the response speed of the field memory B is determined by the signal speed (
When used for band conversion, it does not necessarily have to be a high-speed one. Such a recording operation is performed by pressing the camera's shunter button (not shown) and closing the associated open/close switch V, supplying the recording command signal 13 to the 1liIJ# device J/, and controlling the shunter button. b3/
This is done by controlling the drive unit aS under the control of A signal j/ is supplied to the ImJ N unit 31, and a playback control signal ! from this controller J/ is supplied. 3 and the salmon delivery control signal 33, and this reproduction control signal 4g.
13, by controlling the field memory n with the reproduction and distribution control signal J3 of the recording element n. In other words, the still image information is transferred from the recording element I with the reproduction control signal j.
3, sequentially read data for l fields,
The successive signals are supplied to the field memory n and recorded once. In this case, the readout speed of the recording element 1 does not need to be particularly related to the standard television system. Next, in response to the reproduction control signal j3, the nine-image information is stored in the field memory B and read out sequentially at high speed using a high-speed clock in the field memory, which has a certain relationship with the standard television system. Obtain signal j7 - Convert this I M gzy to an analog image output signal O / by digital-to-analog converter (hereinafter referred to as D/A converter) j9 - Note that the information in field memory n is /field minutes. Since there is only one available in the field memory n, when the page is output, a suspicious interlace is performed repeatedly and the page is continued.

In this way, the video signal becomes compatible with the standard television system. Therefore, by supplying this video output signal 4/ to a television receiver etc., the 1lI
An IIII image of the subject can be seen on the i1 screen. It should be noted that the electronic viewfinder 47 is configured such that the image sensor IS is in operation and the 70m* output signal is sent to the A/D converter/9.
, field memory n, 1 via D/h converter j9
! It is mainly used for direct monitoring. Naturally, it can also be used when looking at fc multiplied signals with nK array elements.By the way, when the subject is moving, the shunter time for obtaining image information is shortened with a normal still camera. I'm trying to make it less blurry! In this way, even in a still image camera using a solid-state image sensor such as the one mentioned above, in order to reduce shank, it is possible to control the shank time to save time depending on the degree of movement of the subject body. There is a need to. For this,
In addition to the method of providing an optical/young image sensor, a so-called 'electronic image sensor' method, which focuses on special characteristics related to imaging of a solid-state image sensor, is applied to still image cameras using a solid-state image sensor. By the way, in the case of still cameras - the use of mechanical, Young's or optical shutters to change the light time has been considered; however, in such a shank, the II adjustment of the shank time In order to carry out this process, there is a drawback that not only a mechanical S component is required, but also that the apparatus becomes large in size. Furthermore, even if it is used as a shank of the solid-state image sensor 15, this solid-state image sensor/
j operates normally only when such a shank is open, so a separate measurement unit is required to install the aperture 13 that determines the amount of light incident on the solid-state image sensor 15. There were some drawbacks, such as: In the case of television cameras that display continuous images, for example, the rotation time can be changed by changing the rotational speed 1' of a mechanical rotary rotor provided in front of the image sensor, but this method has the same drawbacks. Ta.

Next, we will briefly discuss imaging using a solid-state image sensor and the electronic shank used during imaging.

The solid-state image sensor 15 shown in
Let us clarify the case of D. FIG. 2 shows the configuration of the frame transfer CCD. Here, the basic configuration of the solid-state image sensor/S consisting of a frame transfer CCD is as follows:
, vertical signal transfer@/1B and horizontal signal transfer section 15
There are three C. A photoelectric conversion drive signal 7/A is supplied to 15A, a vertical transfer drive signal 77B is supplied to vertical signal transfer 75B, and a horizontal transfer drive signal 7/C is supplied to horizontal signal transfer H15C. These three driving signals? /A, 7/B and 7/C are pulses generated from the drive section DAS under the control of the controller 31. Here, each drive pulse number is λ, which is in phase with each other.
The figure shows the case of two signals and two signals.

Note that as an example of the photoelectric drive signal 7/A, this signal 7/k
The signal waveforms when the drive pulse is formed by four signals are shown in Figures 3 (A) to (C), and the figures (A) to (C), which are enlarged by one, are shown in Figure 3. Water tank, storage tank pulse Pc II
l! In the period TN of TJ, there are frame transfer pulses PFT corresponding to the number of vertical focuses in the solid-state image sensor /j.

Photoelectric conversion drive signal 7/A and vertical transfer drive signal 77B
The pulse signals forming each of these are shown in FIGS. 5A and 5B as a photoelectric conversion drive signal 7/ and a vertical transfer drive signal 7/B/.

In the frame transfer COD as the koji body image sensor 15, in FIG. The image sensor 15 is illuminated by the light from the object.
A photoelectric charge is stored in the photoelectric conversion fi /3 A of . In addition, the frame transfer pulse PFT converts the source of the solid-state image sensor 15 into the converting unit 8A, and converts the photocharge in the vertical signal transfer unit 15 into the vertical signal transfer unit 15.
Transfer to B. Then, line shift pulse PLit
Vertical signal transfer by? %'b/jB is transferred to the optical horizontal signal transfer unit 15C. This is because the storage tank pulse Pc is interlaced every seven fields. In this way, the fc charge transferred to the horizontal signal transfer section 15C is the horizontal transfer drive signal? The output signal 7J is read out in response to the pulse /C, and the subsequent signal 7J is amplified by a h position amplification@7j to obtain an image output m/7.

Since such a still image camera operates in the same way as a television camera, the storage tank time is generally every 740 seconds. Therefore, the accumulation time Tc & the pulse width of the storage tank zpe on the photoelectric conversion system 7/A is 'I'e=(//40-'rN).

It is approximately /6ms. Further, this storage tank time corresponds to the ray time of a still camera.

By the way, as already mentioned, when the accumulation time Tc is long,
When photographing a moving subject, motion blur occurs, so in order to photograph fast-moving subjects in the same manner as with film cameras, it is necessary to shorten this accumulation time Te, and this method is recommended. The person who was there was the aforementioned Oniko Shank. For example, one way a friend can accomplish this goal is by
Fig. rc shows drive s? There is a method of changing the pulse width of the Genka conversion drive signal 7/A that is generated as 1 for s, that is, the photoelectric conversion drive signal 7 that is similar to copper jfi (A).
The accumulation time for the 1M cypress pulse pc at /A/ is shortened by the time TID, as shown in Figure (A). In this way, the accumulation time To is reduced to Te1(”
The motion blur of the image can be improved by shortening the signal to "e Tc*) and obtaining a continuous analog iron image output signal giy as shown in FIG. 3(C)K.

However, in such a drive, the iron image output signal 17
An unfavorable signal appears. In other words, when the pulse pc is shortened, the strong light incident during the time TD generates unfavorable carriers in the light N and the conversion unit ljA, and these carriers are transmitted in the longitudinal direction (vertical direction) in the light 111 conversion unit 15A. This is because it becomes widespread.

Therefore, a so-called vertical smear (hereinafter referred to as the @-component smear component that causes this) occurs on the - plane, which has the disadvantage that a light-wise image cannot be obtained. In addition, the photoelectric change of the image sensor/S! ! ! Miyako/3 In A,
Due to actions such as the Tejanel stomp, the unfavorable force does not spread due to the lateral force (horizontal direction).In addition, the smear is caused by carriers generated during the frame transfer period.
arise.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and to provide a driving method for a solid-state image sensor that can electronically determine the storage time without causing smear.

Such a purpose is to irradiate the solid-state imaging probe with a source related to the subject, obtain image information from the solid-state imaging probe according to the state of the hσ light during the image acquisition period, and store it in the recording section. In the driving method of the solid-state imaging probe, the transfer pulses are transmitted from the image signal acquisition period 11 to Nil.
F! which occurred before the 1lliIfjI signal acquisition period is supplied to the image element. This is achieved by eliminating unnecessary image information based on the AS system.The present invention will now be described in detail with reference to the drawings.

FIGS. 7(A) to 7(C) show signal states in a practical example of the present invention. Here, FD between XJI of the third field,
170, a transfer pulse PTR is added immediately before the accumulation pulse Pc of the original
, and correspondingly as shown in Figure (B). 1
! Direct transfer physical signal 497/81 also transfer pulse PTRII
Add. In this way, the transfer pulse PTRm, PT
The photoelectric conversion drive signal 7/AJ with RI added and the vertical transfer drive signal 7/BJ are driven as shown in FIG.
Generated from a solid-state image sensor (frame transfer CCD)
15.

This platform, the added transfer pulse PTAM, PTRB
The period until #L river, that is, #! 1. 1st. and the period of the third field FD1. The output signal 173 in FD, FD, and K contains a smear component. However, in the third field, the period until the transfer pulse PTR and PTRB are present in PDm+, these added Transfer pulse P
Photoelectric conversion of solid-state image sensor 15 by TIlm and PTilm! I! Both the carrier of the smear component present in section 15A and the photocharge present in working signal transfer section 15B are read out to horizontal signal transfer section 1SC. The isthmus image output signal /73 becomes -1 larger signal (period PD31
reference).

Now, the vertical focus number n of the photoelectric conversion f1515A and the continuous signal transfer capital 15B in the image sensor 15,
Transfer pulses PTRII have the same number of pulses N and I
Depending on the transfer pulses PTRA and PTRB, charge remains only in the vertical transfer section /JB.

Therefore, in the period FD of the third field, the transfer pulse PTRI in the 5th vertical transfer drive number 71BJ is
K N < Since the 't& remaining in the direct dye signal transfer WI/jaK is read out by the line shift pulse PLB, a slight signal component is generated in the optical image output signal /73. In addition, MlfD after 1 package pulse Pel (・4g
The signal component of the isthmus image output signal /73 generated due to the tsrs protrusion becomes large due to the pulse of 7/Bj.However, the pulse width time Tc of the '4M pulse Pcl in the period FD of the third field is , solid-state image sensor/
In the photoelectric conversion unit 15A of S, a smear component only corresponding to the subject is accumulated in a state without a smear component.

For example, if the number n of transfer pulses PTI and PTRI is increased so that N=con, the photoelectric conversion unit /j A and the main signal transfer capital /j B are Since all the charges present in the period PDsa are swept out, there is no video output in the second half period PDsa. Therefore, in this case as well, even if n , photoelectric conversion fM of the solid-state image sensor 15
There is no smear component in s15k. Therefore, during the storage tank time Tel corresponding to the pulse width of the accumulation pulse P (+1), the image charge corresponding only to the subject converts the light into the converter/j
It is stored in A.

In this way, the photocharges stored without a smear component are read out in the next period FD of s+4 dafields.The video output signal 77J (period PD4) obtained by this reading does not include a smear component. Therefore, the scissor image output m/73 in the period PD4 of this third field is converted to digital 0 by A/D conversion@/de.
! After converting to No. 1 No. 1, supply it to field memory n,
1ull image information is stored. Thereafter, as explained in connection with FIG. 1, the stored image information is sequentially written to the recording elements nK. Repeat these steps to record the recording element nK.
wl Record a still image of the subject.

First, in another embodiment of the present invention, the solid-state image sensor l
Another frame transfer CCD used as a water filter. Here, the first drain/SDI is placed in the upper line area of the photoelectric conversion flits 15A of the image sensor 15, and the photoelectric conversion unit I
A second drain 1SD2 is provided as an electrode in the intermediate region between SA and the vertical transfer section DB. Note that the drive pulse is in phase, and the photoelectric conversion drive signal is 7/kll.

Vertical transfer drive signal 77Bda and horizontal transfer drive signal 7/
Figures (A) and (B) show the respective l pulse signals of the direction drive signals 7/kll and 7/Bll shown in Figure 1. In other words, in the photoelectric conversion drive signal 7/Ada, the transfer pulse PTRAI is added to the preceding part of each accumulation pulse pal.
In this drive method, the photoelectric change of the image element 15 during the period TnKm!
! ! The resulting smear formation is discarded by either the 7th drain/ID/or the 15th Drain. Therefore, although λ drains are shown here, either one is fine. For example, if only the seventh drain /jD/ is provided, the photoelectric conversion drive signal 7/A is added to the accumulation pulse P1. The smear component is moved upward by the transferred pulse PTR 1 and #! l Remove from drain /ID/.

In addition, when only the second drain 15DJ is provided, the smear component is moved downward by the transfer pulse PTRAIK and scattered from the second drain /jD.

Note that the direction that determines the direction of moving the smear component upward or downward is the third tuna (A) to tc) and the fourth tuna! Eclipse (A) ~
(C) A number of pulse signals g forming a photoelectric conversion drive signal as shown in K are mutually changed in phase as appropriate.

Using such a frame transfer CCD as a solid-state image sensor/S, coarse transfer pulses PTHAI are generated at regular times corresponding to the number of vertical focus points, and thereby the image pickup image 15
By driving the smear component, all the smear components can be removed from the scissors image field number/7.

FIG. 10 shows another frame transfer CC used in the embodiment of the present invention.
The electrode configuration of the l pixel of D is shown. In the figure, CC of Nda phase
The D element CB transfers the light charge to #M and the charge accumulated here is transferred to the drain DNK (controlling the drain) 1) Controlled by the CG, the charge is transferred to the drain DNK to remove the smear component. Note that the spread of charges in the lateral direction is prevented by the Teyanel stomp C8. Frame transfer CCD with picture elements like this
is used as the solid-state image sensor Is shown in FIG. Image sensor 15 (1) As a drive pulse, I4 (A),
In (B), a beat friend signal is used. drain control goo)
DCG is a CCD element CE in period TD.
The voltage is set so that all the charges are swept out to the drain DN. Also, after the period TID has elapsed, by changing the voltage of the drain control gate DCG, the CCD element CE
In general, drain control gate DCG and drain DN
Some electrodes are provided to discard the charge of the CCD CF when there is excessive light input. In such a case, the voltage is applied to the drain control gate DCG during the period TD. The above-mentioned operation can be performed simply by changing the pressure of 1. In this way,
All smear components can be removed from the isthmus image output signal 17 by the drain DN. The above explanation is all about the so-called frame transfer type CCD, but there are also interline type and interline type CCDs, which have a slightly different structure. There is a CCD called n.

The configuration of this element is shown by $l/-, and this element corresponds to the photoelectric conversion section /jA and the vertical signal transfer section /jB shown in 11. +! Part /31/ and Transfer 5lSII
/ are next to each other. The first frame transfer CCD converts the signal into a frame transfer pulse PFT and transfers the signal from the photoelectric conversion unit/3A to the vertical transfer unit IIB, whereas the CCD shown in riI41/2 applies a signal to the transfer gate.・It is assumed that the photoelectric conversion slSν of the interline CCD uses the same MO8 type electro-liquid conversion ft1i as the frame transfer CCD. ・Figure 12 (A) to (D) In the following, we will show the signal waveform of an example of the interline CCD driving method used in the 11th tuna.

Figure 12 (A), CB) are respectively 8g7 (A),
Corresponding to (B), Fig. 72 (C) is a pulse-like signal applied to the transfer gate.The photoacidity of the interline CCD at the accumulation time Te in the photoelectric conversion drive signal shown in (A) in the figure Photocharge is accumulated in the switching section /Jkl. All the accumulated charges are transferred to the vertical signal transfer section /JB/ at the same time according to the transfer gate voltage (FIL).Then, the vertical signal transfer section /SB/ is sequentially read out to the horizontal signal transfer unit 15C/.Next, a false image output signal is obtained by reading out from the horizontal signal transfer unit 15C/.By the way, in the method of this embodiment, the newly added signal is read out from the horizontal signal transfer unit 15C/. The pulses are a transfer pulse PTRB and a pulse PILI. This brings out the smear component of period t) JI TD,
Thereafter, a scissor image output signal without a smear component in the accumulation period Tel can be obtained in the first field period PD4.For the interline CCD K, the driving method explained in Fig. 1 and Fig. 9 cannot be applied. . Also,
The driving described in connection with the 1011th K can be applied to the drain electrode or the fluorescent part of the interline CCD.

As described above, according to the present invention, the COD accumulation time can be changed by electrical means, and the smear component generated at that time can be removed. As a result, a freely configurable B1-capable still image camera with an accumulation time shorter than 7730 seconds (11 light hours) can be realized without loss of quality.

By shortening this storage time, it is possible to correct motion blur caused by the subject moving during the storage time.In addition, in the present invention, the storage is purely electronic, without using a mechanical shutter. Time periods can be shortened.

After setting the accumulation time freely in this way, you can monitor the output of the integrated image sensor with the electronic viewfinder (Z3), then adjust the camera's grip and wait for the camera to take off in the optimum condition. can. This is # of imaging confectionery.
This would not have been possible if mechanical 7-yanta were provided on the surface.

As described in detail above, by implementing the present invention, it is possible to eliminate the conventional drawbacks and realize an integrated image sensor driving method that can shorten the exposure time and can be applied to still image cameras with high image quality. .

[Brief explanation of the drawing]

Figure 1 is a pronk diagram showing the configuration of a still image camera using a solid-state image sensor, Figure a14 is a companion configuration diagram to explain the solid-state image sensor, Figures 3 (A) to (D) and Figure 3. (A)
~(D) is a signal waveform showing the driving pulse of the solid-state image sensor.
1j Figures (A), (B) and Figures 6 (A) to (C
) is a waveform diagram showing the signals of each part in the conventional drive system,
1g7-(A) to (C) are waveform diagrams showing signals of various parts in #ai@ of the driving method of the solid-state image sensor according to the present invention, and Fig. 1 is a frame transfer COD used in the embodiment of the present invention.
9(A) to <c) are silk l
Figure 1θ is a convex diagram of the structure of another frame transfer CCD used in the embodiment of the present invention, 9411
The figure is a configuration diagram of an interline CCD used in another embodiment of the present invention, and the @/2 figures (^) to (E)) are signal boards for explaining the driving force formula of the interline CCD shown in Fig. 11. It is form 1. l/・Lens, 15...Solid image carrier. n...Field memory, 31...Controller, n...Recording element, 41S...Driver, 71^, ? /
A/, 7/AJ, 7/^J, 7/AJ... Photoelectric conversion drive signal, 7/B, 7/B/, 7/B2.7/
BJ, 7/Bg □= dig direct transfer wAIElIg
No. I, /7, /73, /7...-Image power signal, re + Pc1...Storage tank pulse, Prt
...Frame transfer pulse, PLI...Line 77 pulse, PTILA, PS, 1.1...Transfer pulse, /JD/
, /J~, DN-r/Drain, CF...CCD element, C8...Channel stop-DC (1...Drain iI, lI control gate.

Claims (1)

[Claims] 1) Irradiating light related to a subject onto a solid-state image sensor, -image g
In a driving method for a solid-state image sensor, in which image information corresponding to the light state during the K acquisition period is obtained from the solid-state image sensor and stored in a recording section, a transfer pulse is generated before the ff1l image signal acquisition period. A driving method for a solid-state image sensor, characterized in that the system is configured to supply the light to the solid-state image sensor to eliminate unnecessary image information caused by the light generated before the image signal acquisition period. 2) The image information acquisition period can be variably controlled, and the transfer pulse is configured to have a number related to the number of bits in the vertical direction forming the photoelectric conversion region of the solid-state image sensor. Driving method for a solid-state image sensor according to Claim 1, Item 1, etc. 3) The solid-state image sensor has a photoelectric conversion unit and a complex structure for transferring charges obtained by the photoelectric conversion unit. A driving method for a solid-state imaging device according to claim 1, characterized in that the driving system is an interline solid-state imaging device including a region for converting the reflected light 1. 4) The solid-state image sensor is characterized in that the solid-state image sensor is provided with a drain electrode for eliminating unnecessary image information. ) The accumulated charge mV of the photoelectric conversion section is transferred to the charge transfer section at the same time! A driving method for a solid-state image sensing device as claimed in claim 3, characterized in that primary reading is performed.