JPH0653452A - Solid state image sensor - Google Patents

Abstract

PURPOSE:To reduce chip area by employing a signal output from a horizontal charge transfer section at the time of idle feeding as a reference level thereby eliminating OB section. CONSTITUTION:An optical signal is subjected to optoelectric conversion at an optoelectric converting section 11 and stored in the form of signal charge. Signal charge stored at the optoelectric converting section 11 is read out through a vertical charge transfer section 12 and sequentially output from a signal output section 14 through a horizontal charge transfer section 13. Excessive pulses employed at the horizontal charge transfer section 13 causes idle feeding and a signal output at the time of idle feeding is employed, as a reference level, in signal processing at a signal output section 14. Region 15 is an image sensing section where optoelectric converting sections and vertical charge transfer sections are arranged in matrix. This constitution eliminates the need of optoelectric converting section and vertical charge transfer section at an OB section, and a horizontal charge transfer section connected with the vertical charge transfer section at the OB section.

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 used in a video camera or the like.

[0002]

2. Description of the Related Art Solid-state image pickup devices are widely used in video cameras, surveillance cameras and the like. Hereinafter, a conventional solid-state imaging device will be described with reference to the drawings. Figure 2
The plane schematic diagram of the conventional solid-state imaging device is shown. In FIG. 2, 21 is a photoelectric conversion unit that converts an optical signal into a signal charge and stores the converted signal charge, 22 is a vertical charge transfer unit that vertically transfers the signal charge, and 23 is a vertically transferred signal charge. Is a horizontal charge transfer unit for transferring in the horizontal direction, and 24 is a signal output unit for outputting the horizontally transferred signal charges. The area 25 is a photoelectric conversion section 21 and a vertical charge transfer section 22.
In the region of 26, the photoelectric conversion unit 21 and the vertical charge transfer unit 2 in which the surface is covered with a light shielding film to shield light
Optical black part (hereinafter referred to as O
It is called part B).

The operation of the solid-state image pickup device configured as described above will be described below. First, the photoelectric conversion unit 21 photoelectrically converts the optical signal and accumulates it as a signal charge. The signal charges accumulated in the photoelectric conversion unit 21 are read out to the vertical charge transfer unit 22 and sequentially output from the signal output unit 24 via the horizontal charge transfer unit 23. The output signal output is signal-processed by using the signal output of the OB unit as a reference level.

[0004]

However, in the above structure, in order to obtain the reference level of the signal output,
The OB portion, which requires about 5% of the area of the image pickup portion, is provided, which has the drawback of increasing the chip area.

An object of the present invention is to solve the above problems and to provide a solid-state image pickup device in which the chip area is reduced by omitting the OB portion which requires an area of about 5% of the image pickup portion. Is.

[0006]

In order to achieve this object, the solid-state image pickup device of the present invention is designed to reduce the area occupied by the OB region, which is the reference level of signal output, in order to reduce the photoelectric conversion of the OB region, that is, the OB portion. The horizontal charge transfer unit connected to the conversion unit and the vertical charge transfer unit, and the vertical charge transfer unit of the OB unit or a part thereof is omitted, and the horizontal charge transfer unit is used as a reference level of the signal output of the horizontal charge transfer unit. It is designed to use the signal output at the time of feeding.

[0007]

With this configuration, it is possible to realize a solid-state image pickup device having a small chip area, and a signal at the time of sending is used as a reference pulse because it is generated by a pulse more than the pulse required for transfer in the horizontal charge transfer section. Therefore, the signal processing of the signal output is not hindered.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic plan view of a solid-state imaging device according to an embodiment of the present invention. In FIG. 1, 11 is a photoelectric conversion unit that converts an optical signal into a signal charge and stores the converted signal charge, 12 is a vertical charge transfer unit that vertically transfers the signal charge, and 13 is a vertically transferred signal charge. Is a horizontal charge transfer section for transferring in the horizontal direction, and 14 is a signal output section for outputting the signal charges transferred horizontally. A region 15 is an image pickup unit in which the photoelectric conversion units 21 and the vertical charge transfer units 22 are arranged in a matrix, and the photoelectric conversion unit and the vertical charge transfer units of the OB unit and the vertical charge transfer unit of the OB unit as in the related art. The horizontal charge transfer section connected to is omitted.

The operation of the solid-state image pickup device having the above structure will be described below. First, the photoelectric conversion unit 11 photoelectrically converts the optical signal and accumulates it as a signal charge. The signal charges accumulated in the photoelectric conversion unit 11 are read out to the vertical charge transfer unit 12 and sequentially output from the signal output unit 14 via the horizontal charge transfer unit 13. At this time, the horizontal charge transfer unit 1
By using a pulse more than the pulse necessary for the transfer in No. 3, the extra pulse causes the feed, and the signal output unit 14 sets the signal output at the time of the feed as the reference level.
Signal processing in.

In such a solid-state image pickup device, the conventional OB portion, which requires an area of about 5% of the image pickup portion, is not required, so that the chip area can be reduced. As described above, according to the present embodiment, the signal output at the time of sending from the horizontal charge transfer section is set to the reference level, so that the OB section can be omitted and the chip area can be reduced.

In the embodiment of the present invention, the photoelectric conversion section and the vertical charge transfer section of the OB section and the horizontal charge transfer section connected to the vertical charge transfer section of the OB section are not provided. , The horizontal charge transfer section connected to the vertical charge transfer section of the OB section may be omitted.

[0012]

As described above, according to the present invention, the signal output at the time of sending from the horizontal charge transfer section is used as the reference level, so that the OB section is omitted and a solid-state image pickup device having a small chip area is realized. be able to.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a solid-state imaging device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a conventional solid-state imaging device.

[Description of Reference Signs] 11 photoelectric conversion unit 12 vertical charge transfer unit 13 horizontal charge transfer unit 14 signal output unit 15 imaging unit

Claims (2)

[Claims] 1. A solid-state imaging device including a photoelectric conversion unit, a vertical charge transfer unit, a horizontal charge transfer unit, and a signal output unit arranged in a matrix, wherein an OB (optical black) region serving as a reference level of signal output. The solid-state imaging device is characterized in that the signal output at the time of sending from the horizontal charge transfer unit is set to the reference level. 2. The solid-state imaging device according to claim 1, wherein the photoelectric conversion unit / vertical charge transfer unit in the OB region and the horizontal charge transfer unit connected to the vertical charge transfer unit in the OB region are not provided.