JPS62141867A - Solid-state image pickup element - Google Patents

Abstract

PURPOSE:To reduce remarkably the reset time by turning on vertical switches simultaneously attached to a photoelectric converting element of each picture element. CONSTITUTION:Vertical selection lines 6 connected to each gate of vertical MOS switches 5 arranged in the row direction are connected at the opposite side of vertical shift registers 2 to a source of a control FET 9 and drains of the control FETs 9 are connected to a common control drain 11. Further, the gates are connected to a common control line 10 and controlled. On the other hand, when the control line 10 goes to a high level, each control FET 9 is turned on to turn on the vertical MOS switch 5 attached to all picture elements at the same time. In applying horizontal scanning to the horizontal shift registers 1 in this state, all picture elements are scanned at once, the residual electric charge of each picture element is read simultaneously to reset photo diodes 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a solid-state image sensor, and more particularly to an MO3 solid-state image sensor whose reset time is significantly shortened.

(Prior art) MO3 type solid-state image pickup element As shown in FIG. It consists of a horizontal MOS switch 4, a vertical scanning circuit 2, and a horizontal scanning circuit 1.

In such a solid-state image sensor, resetting the photoelectric conversion element of each pixel, for example, a photodiode as shown, is performed by reading each pixel once.

When this solid-state image sensor is used for a video camera,
A video camera is continuously operated in a series of sequences, and resetting is also performed sequentially following an image readout operation.

Therefore, it is only necessary to reset the element itself for the first screen when the camera is powered on.

(Problem to be solved by the invention) However, it is difficult to use such solid-state image sensors as electronic stills.
When applied to a camera, etc., when a single phenomenon Y tlI + image is taken, it is necessary to perform a blank readout and reset each time immediately before taking an image. Therefore, it takes a long time until the screen is read out. It cost. As is clear from FIG. 3, the long time it takes for the reset increases the time required for the entire system, which is determined by the reset time, imaging time, and readout time. This resulted in a situation that could not be adequately handled when continuous shooting was performed with a camera.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a solid-state image sensor in which the reset time can be significantly reduced.

(Means and actions for solving problems) That is,
The above-mentioned object of the present invention is to provide a solid-state device consisting of photoelectric conversion elements arranged in an IJ box shape, vertical switches attached to these photoelectric conversion elements, horizontal switches attached to vertical signal lines, a vertical scanning circuit, and a horizontal scanning circuit. In the image sensor, the vertical selection line of each row is connected to the source of a control FET on the side opposite to the vertical scanning circuit, and the drain side of this control FET is connected to the control drain common to each vertical selection line. This is achieved by a solid-state image sensing device characterized in that the gate is connected to a common control line and the gate is connected to a common control line.

According to this configuration, the original signal charge is removed by sequentially switching each switching element using each scanning pulse from the vertical scanning circuit and the horizontal scanning circuit, as in the conventional case.
Ru. On the other hand, at the time of reset, all the vertical switches are turned on at once and all residual charges in one element are read out for one horizontal scan, thereby performing a short reset.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of an MO8 type solid-state image sensor according to the present invention. This solid-state image sensing device has substantially the same structure as the well-known one, and therefore, the same reference numerals as in FIG. 3 are used for the same parts.

That is, the photodiodes 8 arranged in a matrix, the vertical MOS switches 5 attached to these photodiodes 8, the horizontal MOS switch 4 attached to the vertical signal line 7, and the vertical MOS switch 5 and horizontal MOS switch 4 are switched in sequence. It consists of a vertical shift register 2 and a horizontal shift register 1 that operate. In addition to this conventional element, the element of the present invention further includes an output side of each vertical selection line 6;
That is, a control FET 9Y is provided on the opposite side from the vertical shift register 2. More specifically, the vertical selection line 6 connected to each gate of the vertical MOS switch 5 arranged in the row direction is located on the side opposite to the vertical shift register 2.
The control FET 9 is connected to the source of the control FET 9, and each drain of the control FET 9 is connected to a common control drain 11. In addition, those gates are connected to a common control line 10 to control ζ
nru.

The solid-state image sensing device of the present invention having the above-mentioned configuration garb lowers the voltage level of the control line 10.
斤台”Lererol’? 1f1h red 1 The signal charge is read out.

That is, when the control line 10 is at a low level,
Each row of the row device or vertical MOS switch 5 is sequentially selected by vertical scanning from the vertical shift register 2.
, On the other hand, the horizontal scanning from the horizontal shift register 1 causes the horizontal MOS switches 4 to be sequentially switched and the vertical signal line 7 to be selected, so that the signal charges accumulated in each pixel are sequentially transferred to the output line. Read it from here.

On the other hand, when the control line 10 goes high, each control FET 9 is turned on and the vertical MOS switches 5 attached to all pixels are turned on. In such a state, when the horizontal shift register 1 is scanned horizontally, all pixels are scanned at once, and the residual charges of each pixel are read out all at once, and the photodiode 8 is reset.

(Effects of the Invention) As described above, the solid-state image sensor of the present invention has the following effects:
By providing the vertical switches attached to the photoelectric conversion elements of each pixel to be turned on all at once, the charges of all pixels can be read out with just one horizontal scan, thus reducing the reset time. Moreover, this reset time can be shortened regardless of the drive frequency of the shift register, and the reduction rate is at least equal to 1/the number of pixels in the vertical direction.
Wear.

Furthermore, the present invention can be achieved by simply adding a few .xi. turns to the periphery of the conventional element, and this addition does not significantly increase manufacturing costs. Therefore, according to the present invention, n
For example, it is possible to obtain a solid-state image sensor with a significantly shortened reset time with a slight increase in cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram illustrating an embodiment of a solid-state image sensor according to the present invention, FIG. 2 is a circuit diagram illustrating a conventionally known solid-state image sensor, and FIG. 3 is a diagram illustrating system time until image readout. be. 1...Horizontal scanning circuit (horizontal shift register), 2...
・Vertical scanning circuit (vertical shift register), 3... Output line, 4... Horizontal MOS switch, 5... Vertical MOS
switch, 6... vertical selection line, 7... vertical signal line,
8... Optical timing probe (photodiode), 9...
Control FET, 10... Control ship, 1
1...Control Drain Representative Patent Attorney (8107) Kiyoshi Sasaki
(2 others) ゛. 1st Figure 1-1 s 2 Figure 7 Surface A ° Lise To 5 false IJi, clb Rutami 7 (Bsr
, 7B appearance ■9. Photo time C mountain 1 motion tltb and (B now T hate

Claims (1)

[Claims] In a solid-state imaging device consisting of photoelectric conversion elements arranged in a matrix, vertical switches attached to these photoelectric conversion elements, horizontal switches attached to vertical signal lines, a vertical scanning circuit, and a horizontal scanning circuit, vertical selection lines in each row is connected to the source of a control FET on the side opposite to the vertical scanning circuit, and this control FET has a drain side connected to a control drain common to each vertical selection line, and a gate connected to the common control line. A solid-state image sensor characterized by: