JPH0628369B2 - Solid-state imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid contact image sensor, and more particularly to a long contact image sensor in which a plurality of chips are arranged.

Configuration of Conventional Example and Problems Thereof In recent years, development of a so-called contact image sensor in which a one-dimensional solid-state image sensor is arranged in multiple chips to have the same size as a document has been actively promoted, and part of the level of practical application has been reached. I'm doing it. FIG. 1 is a schematic view of a conventional CCD one-dimensional solid-state image pickup device, and FIG. 2 is a main part of a passage through which charges pass in the structure of FIG. In FIGS. 1 and 2, (1) is a photoelectric conversion unit, and (2) is a photoelectric conversion unit (1).
A shift gate that transfers the charges accumulated in the CCD shift register (3) after being accumulated for a certain period, (4) is an input source of the CCD, and (5) is an output unit. In such a conventional element, the transfer section or the input / output section is projected outside the end pixel (1e). For this reason, when a so-called contact type image sensor in which a plurality of the above-mentioned conventional chips are arranged in the same size as the original is made, in order to arrange the pixels in the pixel arrangement direction without interruption, a zigzag arrangement is formed as shown in FIG. I will end up.

In such a staggered contact image sensor, a pixel line shift due to the staggered arrangement is corrected by a memory circuit, and the optical system becomes complicated, which also causes a cost increase.

Object of the Invention It is an object of the present invention to provide a cheaper solid-state imaging device capable of linear array.

According to the solid-state imaging device of the present invention, a charge transfer section is arranged on a chip in which a plurality of photoelectric conversion sections are arranged to form a one-dimensional solid-state image sensor, and the charge transfer section is used as the photoelectric conversion section. And a portion having a smaller pitch than the photoelectric conversion unit and a portion having a pitch smaller than the photoelectric conversion unit, and arranged in a state corresponding to both ends of the arrangement of the photoelectric conversion unit and the portion having a smaller pitch than the photoelectric conversion unit of the charge transfer unit, It is characterized in that the charge transfer section is housed in a position within the entire width of the plurality of photoelectric conversion sections.

Further, the charge transfer unit according to claim 1 is composed of a shift register and a wiring arranged corresponding to the input / output unit and the photoelectric conversion unit, and the shift register on the output side is arranged on the axis of this arrangement. It is characterized by being bent at an angle of 45 degrees.

Description of Embodiments An embodiment of the present invention will be described below with reference to FIGS. FIG. 4 is a one-dimensional CCD according to an embodiment of the present invention.
FIG. 5 is a schematic view of the image pickup device, and FIG. 5 shows a main part of a passage through which electric charges pass in the structure of FIG. In FIGS. 4 and 5, (1) is the photoelectric conversion unit, (2) is the charge accumulated in each photoelectric conversion unit (1) for a certain period, and then the CCD shift register (3) Is a shift gate to be transferred to the CCD, (4) is an input source of the CCD, and (5) is an output unit. In the device of this embodiment shown in FIGS. 4 and 5, the charge transfer unit A including the input / output unit is the photoelectric conversion unit (1).
Is smaller than the pitch P of the photoelectric conversion unit (1), and is smaller than the pitch P of the photoelectric conversion unit (1) of the charge transfer unit A. The portions arranged at the pitch are arranged so as to correspond to both ends of the arrangement of the photoelectric conversion units (1), and the charge transfer unit A is inside the pixel (1e) at the chip end, that is, the photoelectric conversion units.
They are accommodated on the same chip within the entire width L of (1).

Regarding the difference in pitch depending on the charge transfer portion A,
It will be specifically described with reference to the drawings. In FIG. 5, the shape near the left and right ends is bilaterally symmetrical between the both ends, so here, the shape near the ends will be described only for the left side. P, Pa1, Pa2, and Pa3 are the pitches of the photoelectric conversion units (1), and are formed to be equal to each other. Reference numerals 2a, 2b, 2c, and 2d are wirings that connect each photoelectric conversion unit (1) and the shift register (3) of the charge transfer unit A, respectively. n1 is the wiring 2 for the pitch Pa2
It is the deviation of the connection point between c and the shift register (3), and n2
Is the wiring 2d for the pitch Pa3 and the shift register (3)
It is the deviation of the connection point with. Here, n1 and n2 are formed to be equal. Pb1 and Pb2 are pitches between connection points of the wirings 2b, 2c and 2d and the shift register (3), respectively, and pitches of the shift register (3) to which the wirings 2b, 2c and 2d are connected, and Is
It is also the pitch of the charge transfer portions A. In the range of L1, each photoelectric conversion unit (1) and the shift register (3) are connected to the wiring 2a, which is laid down from the center of each photoelectric conversion unit (1) in a downward direction.
It is connected by 2b. Therefore, the charge transfer section A in this range is formed with the same pitch as the photoelectric conversion section (1). In the range of L2, the pitch Pb1 becomes a value obtained by subtracting the deviation n1 from the pitch Pa2,
b2 has a value obtained by subtracting the deviation n2 from the pitch Pa3. Therefore, the charge transfer section A in this range is formed with a smaller pitch than the photoelectric conversion section (1).

With this structure, the charge transfer section A and the photoelectric conversion section are accommodated while the charge transfer section A is accommodated within the entire width L of the photoelectric conversion section (1).
It is possible to reduce the complication of the shape of the charge transfer portion A that occurs when the width of (1) is made to correspond. Therefore, it is possible to reduce an increase in design time and an increase in cost for mask making.

Further, in the charge transfer section A formed as described above, as shown in FIG. 5, the shift register (3) is arranged on the output side of the output section 5 with respect to the arrangement axis S of the shift register (3). It is bent at an angle of 45 degrees in the direction and connected to the output unit 5.

With this configuration, the width-to-length ratio of this portion, which is generated when the shift register (3) is bent, is reduced while accommodating the charge transfer portion A within the entire width L of the photoelectric conversion portion (1). The decrease in charge transfer efficiency can be reduced. Particularly, a remarkable effect can be obtained at high speed driving. Therefore, when a plurality of elements of this embodiment are arranged to form a contact type solid-state image pickup device, the structure is as shown in FIG. 6, and the arrangement on a straight line is possible.

EFFECTS OF THE INVENTION As described above, in the solid-state imaging device of the present invention, the charge transfer section is located within the full width of the photoelectric conversion section by forming the portion having the pitch smaller than that of the photoelectric conversion section only on both ends of the charge transfer section. It is possible to reduce the complication of the shape of the charge transfer portion that occurs when the widths of the charge transfer portion and the photoelectric conversion portion are made to correspond to each other while being accommodated in the. Therefore, it is possible to reduce an increase in design time and an increase in cost for mask making.

Further, the shift register on the output side of the charge transfer unit is bent at an angle of 45 degrees with respect to the axis of this array, so that the charge transfer unit is accommodated within the entire width of the photoelectric conversion unit while shifting. The decrease in the charge transfer efficiency due to the decrease in the width-to-length ratio of this portion which occurs when the register is bent can be reduced. Particularly, a remarkable effect can be obtained at high speed driving.

For these reasons, it is possible to arrange the chips on a straight line, and it is possible to obtain a cheaper solid-state imaging device without the need for complicated correction in the memory circuit as in the conventional case, and the practical effect thereof is great. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are schematic views of a conventional one-dimensional CCD solid-state imaging device, and FIG. 3 is a plan view of a contact-type imaging device in which a plurality of conventional one-dimensional solid-state imaging devices are arranged. FIGS. 4 and 5 are schematic views of an embodiment of the solid-state imaging device of the present invention, and FIG. 6 is a plan view of a contact-type imaging device in which a plurality of one-dimensional solid-state imaging devices of this embodiment are arranged. . (1) …… photoelectric conversion part, (2) shift gate, (3) …… shift register, (4) input source, (5) …… output part, A,
B: chip, L: full width of photoelectric conversion part

Claims (2)

[Claims] 1. A one-dimensional solid-state imaging device is constructed by disposing a charge transfer section on a chip in which a plurality of photoelectric conversion sections are arrayed, and the charge transfer section is a portion having a pitch equal to that of the photoelectric conversion section. A plurality of charge transfer parts are formed by arranging the part having a pitch smaller than that of the photoelectric conversion part, and arranging the part of the charge transfer part having a pitch smaller than that of the photoelectric conversion part at both ends of the arrangement of the photoelectric conversion parts. Solid-state imaging device housed in a position within the full width of the photoelectric conversion part. 2. A charge transfer section is composed of a shift register and wiring arranged in correspondence with an input / output section and a photoelectric conversion section, and the shift register on the output side is 45 with respect to the axis of this array.
The solid-state imaging device according to claim 1, wherein the solid-state imaging device is bent at an angle of degrees.