JP2007028285A - Contact image sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive image sensor which is capable of diminishing discontinuity of image quality at a joint between photoelectric conversion devices which constitute a contact image sensor composed of two or more photoelectric conversion devices. <P>SOLUTION: The photoelectric conversion device is equipped with two or more light receiving element rows which are arranged in parallel with each other in an auxiliary scanning direction, and the light receiving element is equipped with output reading wiring for extracting output signals. The contact image sensing sensor is composed of the photoelectric conversion devices which are rectilinearly arranged in a main scanning direction, and the output reading wiring of the light receiving elements arranged on both ends of the photoelectric conversion device is properly used through a certain arrangement method so as to narrow a light receiving element pitch at a joint between the photoelectric conversion devices. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joint between a photoelectric conversion device and a photoelectric conversion device of a contact image sensor that constitutes a plurality of photoelectric conversion devices.

  2. Description of the Related Art In recent years, in the field of photoelectric conversion devices, CCD sensors using a reduction optical system and equal-magnification contact image sensors mounted with a plurality of photoelectric conversion devices have been actively developed.

  Japanese Patent Application Laid-Open No. 2003-32437 has the following arrangement of light receiving elements.

  FIG. 4 shows a layout of the light receiving elements used in Japanese Patent Laid-Open No. 2003-32437.

  FIG. 5 is an enlarged view of a joint portion of two photoelectric conversion devices used in Japanese Patent Laid-Open No. 2003-32437.

  In FIG. 5, RGB primary color filters are formed on each light receiving element of the contact image sensor 2024. 2024-1 is a light receiving element array in which light receiving elements in which an R filter that transmits a red wavelength component in visible light is formed are arranged in one line.

  Reference numerals 2024-2 and 2024-3 denote light-receiving element arrays in which light-receiving elements each having a G filter and a B filter that transmit the wavelength components of green light and blue light are arranged in one line. In the prior art, the pitch of the light receiving elements disposed between the photoelectric conversion devices is twice the light receiving element pitch of the photoelectric conversion devices. By doubling the normal light receiving element pitch of the photoelectric conversion device, one light receiving element is missing between the photoelectric conversion devices. In order to correct this, by using the signals generated from the light receiving elements at both ends and performing pixel processing, discontinuity appearing in the image quality at the joint between the photoelectric conversion device and the photoelectric conversion device can be reduced.

  Japanese Unexamined Patent Application Publication No. 2004-172836 has the following arrangement of light receiving elements.

  FIG. 6 shows a layout of the light receiving elements used in Japanese Patent Application Laid-Open No. 2004-172836.

On the RED, GREEN, and BLUE light receiving elements of the contact image sensor 2024, RGB color filters of the three primary colors are formed. The light receiving area of the light receiving elements arranged in the photoelectric conversion devices at both ends is characterized by having a smaller area than the normal light receiving element of the photoelectric conversion device. By doing so, the light receiving element pitch at both ends of the photoelectric conversion device is narrowed, and therefore, discontinuity appearing on the image quality at the joint portion of the photoelectric conversion device can be reduced.
Japanese Patent Laid-Open No. 2003-32437 JP 2004-172836 A

  FIG. 5 of Japanese Patent Application Laid-Open No. 2003-32437 shows an enlarged view of a joint portion between two photoelectric conversion devices.

  In the contact type image sensor having a plurality of light receiving element arrays as shown in FIG. 5, in order to reduce discontinuities appearing on the image quality at the joint portion of the photoelectric conversion device, the light reception arranged at both ends of the photoelectric conversion device. Appears on the image quality at the joint between the photoelectric conversion device and the photoelectric conversion device by performing pixel processing using the signals generated from the light receiving elements at both ends, making the element twice the normal light receiving element pitch of the photoelectric conversion device Discontinuity can be reduced. However, when image processing is performed inside the photoelectric conversion device, a semiconductor region for the image processing circuit is required, which causes a cost increase. For example, even when image processing is performed outside the photoelectric conversion device, it causes a load on the user, and therefore this method is not effective.

  FIG. 7 of Japanese Patent Application Laid-Open No. 2004-172836 shows an arrangement diagram of two photoelectric conversion devices and a light source.

  FIG. 6 shows a layout of the light receiving elements used in Japanese Patent Application Laid-Open No. 2004-172836.

  In the contact type image sensor having a plurality of light receiving element arrays as shown in FIG. 6, in order to reduce discontinuity appearing in the image quality at the joint portion of the photoelectric conversion device, it is arranged in the photoelectric conversion devices at both ends. The light receiving area of the light receiving element is smaller than that of the normal light receiving element of the photoelectric conversion device, and the light receiving element pitch at the joint portion of the photoelectric conversion device is narrowed. This means can reduce the discontinuity appearing on the image quality at the joint portion of the photoelectric conversion device. However, it is clear that the sensitivity is lowered by the reduction of the light receiving area of the light receiving elements arranged at both ends of the photoelectric conversion device, and is lower than the normal light receiving device sensitivity of the photoelectric conversion device. In order to improve the sensitivity of the light receiving elements arranged at both ends of the photoelectric conversion device, it is necessary to partially increase the brightness of the LED as the light source as shown in FIG. .

  As described above, both conventional techniques have advantages and disadvantages.

In order to solve the above problems, the contact image sensor of the present invention has a plurality of photoelectric conversion devices arranged in a straight line in the main scanning direction on a common substrate, and the photoelectric conversion devices are sub-scanned in parallel with each other. In a contact-type image sensor having a plurality of light receiving element arrays arranged in a direction and each light receiving element having an output read wiring for taking out an output signal, an appropriate output read wiring for the light receiving element of the photoelectric conversion device is provided. The discontinuity that appears in the image quality at the joint portion of the photoelectric conversion device is reduced by narrowing the light receiving element pitch at the joint portion between the photoelectric conversion device and the photoelectric conversion device using the arrangement method. The discontinuity that appears in the image quality at the joint between the photoelectric conversion device and the photoelectric conversion device can be reduced without changing the light receiving area of the light receiving element and without performing image processing. it can.

  As described above, the present invention provides an inexpensive image sensor that reduces the pitch of the light receiving elements at the joints of the photoelectric conversion device, reduces the discontinuity that appears in the image quality at the joints of the photoelectric conversion device, and provides an inexpensive image sensor. Can be realized.

  Hereinafter, the drawings of the embodiments of the present invention will be shown, and the details of the present invention will be described using these drawings.

  In the present invention, a plurality of photoelectric conversion devices are linearly arranged in the main scanning direction. By reducing the light receiving element pitch at the joint between the photoelectric conversion device and the photoelectric conversion device to the light receiving element pitch of the photoelectric conversion device, the discontinuity that appears in the image quality at the joint between the photoelectric conversion device and the photoelectric conversion device is reduced. It is invention regarding.

  FIG. 1 shows an image diagram of a contact image sensor in which a plurality of photoelectric conversion devices are mounted in a line.

  In FIG. 1, a contact type image sensor in which ten photoelectric conversion devices (201-210) are mounted in a line on the substrate (100) is a joint (ZOOM) formed between the photoelectric conversion devices. Occurs. The pitch of the light receiving elements arranged at both ends of the photoelectric conversion device is determined by the width of the photoelectric conversion device and the photoelectric conversion device. Essentially, the pitch of the light receiving elements is desired to be equal to the normal light receiving element pitch inside the photoelectric conversion device. However, there is a limit depending on the mounting technology of the photoelectric conversion device. Further, when cutting the wafer in order to protect the circuit of the photoelectric conversion device, it is necessary to leave a vacant area called “scribing” at both ends of the photoelectric conversion device. Accordingly, when a plurality of photoelectric conversion devices are linearly arranged in the main scanning direction, a gap is formed at the joint portion between the photoelectric conversion device and the photoelectric conversion device, and the light receiving element pitches arranged at both ends of the photoelectric conversion device are the same. It becomes wider than the normal light receiving element pitch.

  FIG. 2 shows an image diagram assuming an output readout wiring arranged around the joint portion between the photoelectric conversion device and the photoelectric conversion device, using FIGS. 4 and 5 of JP-A-2003-32437.

  FIG. 2 is an enlarged view of a joint (ZOOM) between the photoelectric conversion device and the photoelectric conversion device. In FIG. 2, the first photoelectric conversion device 201 includes a light receiving element array (R598, R599, R600) in which a light receiving element in which an R filter that transmits a red wavelength component in visible light is formed is arranged in a line, visible light. Light receiving element array (G598, G599, G600) in which light receiving elements with G filters that transmit green wavelength components are arranged in a line, and B filters that transmit blue wavelength components in visible light A light receiving element array (B598, B599, B600) in which the formed light receiving elements are arranged in a line, a read circuit 4 for the R light receiving element, a read circuit 5 for the G light receiving element, a read circuit 6 for the B light receiving element, a plurality of Circuit 7 that processes and outputs signals from the light receiving element array, output readout wiring for R light receiving elements (r598, r599, r600), output readout wiring for G light receiving elements (g598, g599, g600), B Output readout wiring for light receiving elements (b598, b599, b600), second photoelectric conversion device 202 is visible Light receiving element array (R1, R2, R3) in which light receiving elements with R filters that transmit red wavelength components are arranged in a line, and G filters that transmit green wavelength components in visible light Light receiving element array (G1, G2, G3) in which the formed light receiving elements are arranged in a line, and a light receiving element in which a B filter that transmits a blue wavelength component in visible light is formed is arranged in a line Processes and outputs signals from column (B1, B2, B3), readout circuit 4 for R light receiving element, readout circuit 5 for G light receiving element, readout circuit 6 for B light receiving element, and a plurality of light receiving element rows Circuit section 7, output readout wiring for R light receiving element (r1, r2, r3), output readout wiring for G light receiving element (g1, g2, g3), output readout wiring for B light receiving element (b1, b2, b3 ).

  As shown in FIG. 2, two outputs are output between the light receiving element array 600 disposed at the end of the first photoelectric conversion device and the light receiving element array 001 disposed at the end of the second photoelectric conversion apparatus. Readout wiring (g600 wiring and r1 wiring) is arranged.

  Equation (1) below shows a formula for calculating the light receiving element pitch at the joint portion of the photoelectric conversion device (see FIG. 2).

Minimum width that can be mounted = b
Light receiving element pitch at the joint of the photoelectric conversion device = c
Distance from the center of the light receiving element arranged at both ends to the etch of the photoelectric conversion device = e
c = 2e + b (1)
For example, if the output read wiring rule Line / Space is 2 um / 2 um, 8 um for two wirings occupy the distance from the center of the light receiving element arranged at both ends to the etch of the photoelectric conversion device. The pitch of the light receiving elements arranged at the joint portion of the photoelectric conversion device is occupied by the 8 μm output readout wiring. The pitch of the light receiving elements arranged in the joint portion of this photoelectric conversion device increases in proportion to the number of columns of the light receiving elements, and the discontinuity appearing on the image quality at the joint portion also deteriorates in proportion thereto. The output readout wiring for 2 lines (8um) is occupying 1/4 of the light receiving element pitch for the normal light receiving element pitch of 42um of the 600dpi contact type image sensor. Is an important element that cannot be ignored.

  FIG. 3 is a plan view of the embodiment of the present invention, and shows an enlarged view of a joint portion (ZOOM) between the photoelectric conversion device and the photoelectric conversion device.

  FIG. 3 is an enlarged view of the last light receiving element portion of the first photoelectric conversion device and the first light receiving element of the second photoelectric conversion device in FIG. 3. As shown in FIG. 2, the first photoelectric conversion device 201 has a light receiving element array (R598, R599, R600) in which light receiving elements on which an R filter that transmits a red wavelength component in visible light is formed are arranged in a line. ), A light receiving element array (G598, G599, G600) in which light receiving elements on which a G filter that transmits green wavelength components in visible light is formed are arranged in a line, and transmits blue wavelength components in visible light Light receiving element array (B598, B599, B600) in which light receiving elements on which a B filter is formed are arranged in a line, readout circuit 4 for R light receiving element, readout circuit 5 for G light receiving element, readout for B light receiving element Circuit 6, circuit unit 7 for processing and outputting signals from a plurality of light receiving element arrays, output read wiring for R light receiving elements (r598, r599, r600), output read wiring for G light receiving elements (g598, g599, g600), output readout wiring for B light receiving element (b598, b599, b600), second photoelectric conversion device 202 Light receiving element array (R1, R2, R3) in which light receiving elements with R filters that transmit red wavelength components in visible light are arranged in a line, G that transmits green wavelength components in visible light Light receiving element array (G1, G2, G3) in which light receiving elements with filters are arranged in a line, and light receiving elements in which B filters that transmit blue wavelength components in visible light are arranged in a line Light receiving element array (B1, B2, B3), read circuit 4 for R light receiving element, read circuit 5 for G light receiving element, read circuit 6 for B light receiving element, process signals from multiple light receiving element arrays Output circuit part 7, output readout wiring for R light receiving element (r1, r2, r3), output readout wiring for G light receiving element (g1, g2, g3), output readout wiring for B light receiving element (b1, b2 , b3).

  As shown in FIG. 3, the output readout wiring (g600 wiring) of the first photoelectric conversion device is arranged between the light receiving element row 599 and the light receiving element row 600, and the output readout wiring (r1 wiring) of the second photoelectric conversion device. Is arranged between the light receiving element row 001 and the light receiving element row 002, thereby reducing the light receiving element pitch at the joint portion of the photoelectric conversion device.

  Equation (2) below represents a formula for calculating the light receiving element pitch at the joint portion of the photoelectric conversion device (see FIG. 3).

Minimum width that can be mounted = b
Light receiving element pitch at the joint of the photoelectric conversion device = c
Distance from the center of the light receiving element arranged at both ends to the etch of the photoelectric conversion device = e
c = 2 (e-4um) + b (2)
When the normal light receiving element pitch of the photoelectric conversion device is d, the light receiving element pitch at the joint portion of the photoelectric conversion device of the present invention is limited to the following equation (3).

d ≥ c ≤ 2d (3)
In the above embodiment, the contact type image sensor having the RED, GREEN, and BLUE light receiving elements is mainly described as an example. Obviously, similar effects can be obtained by doing so.

It is an adhesion type image sensor image figure in which a plurality of photoelectric conversion devices in Embodiment 1 of the present invention are mounted in a line shape. It is the enlarged view of the joint part (ZOOM) of the photoelectric conversion apparatus assumed by Unexamined-Japanese-Patent No. 2003-32437 in a prior art, and a photoelectric conversion apparatus. It is an enlarged view of the joint part (ZOOM) of the photoelectric conversion apparatus in Embodiment 1 of this invention, and a photoelectric conversion apparatus. It is an arrangement view of light receiving elements used in Japanese Patent Application Laid-Open No. 2003-32437 in the prior art. It is a joint part enlarged view of two photoelectric conversion apparatuses used by Unexamined-Japanese-Patent No. 2003-32437 in a prior art. It is an arrangement view of light receiving elements used in Japanese Patent Application Laid-Open No. 2004-172836 in the prior art. It is an arrangement diagram of two photoelectric conversion devices and light sources used in Japanese Patent Application Laid-Open No. 2004-172836 in the prior art.

Explanation of symbols

101 Common substrate for mounting photoelectric conversion device 201 First photoelectric conversion device 202 Second photoelectric conversion device 203 Third photoelectric conversion device 204 Fourth photoelectric conversion device 205 Fifth photoelectric conversion device 206 Sixth photoelectric conversion device 207 Seventh photoelectric Conversion device 208 Eighth photoelectric conversion device 209 Ninth photoelectric conversion device 210 Tenth photoelectric conversion device 4R Reading circuit for light receiving element 5G Reading circuit for light receiving element 6B Reading circuit for light receiving element 7 Process signals from a plurality of light receiving element rows Output circuit
R1, R2, R3, R598, R599, R600 RED photo detector
r1, r2, r3, r598, r599, r600 RED photo detector output readout wiring
G1, G2, G3, G598, G599, G600 GREEN photo detector
g1, g2, g3, g598, g599, g600 GREEN light receiving element output readout wiring
B1, B2, B3, B598, B599, B600 BLUE photo detector
b1, b2, b3, b598, b599, b600 BLUE light receiving element output readout wiring

Claims (3)

  A plurality of photoelectric conversion devices having a plurality of light receiving element arrays arranged in parallel to each other in the sub-scanning direction, and each of the light receiving elements having an output readout wiring for taking out an output signal are linear in the main scanning direction. In the contact-type image sensor disposed in the photoelectric conversion device, the output readout wirings of the light receiving elements disposed at both ends of the photoelectric conversion device should not be disposed between the light receiving elements disposed at the extreme end of the adjacent photoelectric conversion device. Contact type image sensor characterized by   In the arrangement of the output read wiring of the light receiving elements arranged at both ends of the photoelectric conversion device, the arrangement of the output read wiring of the light receiving elements arranged at both ends of the photoelectric conversion device should be arranged between the light receiving elements of the photoelectric conversion device. 2. The contact image sensor according to claim 1, wherein   In the light receiving element pitch arranged at both ends of the adjacent photoelectric conversion device, d is the normal light receiving element pitch of the photoelectric conversion device, and c is the light receiving element pitch arranged at both ends of the photoelectric conversion device. 2. The contact image sensor according to claim 1, wherein d ≧ c ≦ 2d.

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