JP2008228348A - Line sensor chip, line sensor, image information reader, facsimile, scanner and copier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a line sensor in which an image is prevented from being distorted by presence of a chip gap. <P>SOLUTION: A line sensor 4, including a plurality of pixels 21 as many as a number corresponding to a resolution, includes: a first group of pixels which is provided in the center of the plurality of pixels arranged linearly and in which a pixel pitch is shorter than a length corresponding to a pixel pitch PS calculated from the resolution; and a second group of pixels which is provided in both side portions of the center, respectively, and in which a pixel pitch is longer than the length corresponding to the pixel pitch PS calculated from the resolution. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a line sensor and an image information reading apparatus.

Conventionally, as a solid-state imaging device, CCD (Charge coupled device) sensor, CMOS
There are sensors, and line sensors of solid-state imaging devices are widely used in scanners, copiers, facsimiles, and the like. The solid-state imaging device includes a plurality of photodiodes that receive light and generate charges, and functions as a photoelectric conversion element. For example, the amount of photo-generated charges generated in each photodiode is the region where the photodiode is formed via the transfer gate (hereinafter referred to as the
It is transferred to a charge transfer section such as a CCD provided adjacent to one side of the photodiode formation region. The charge transfer unit transfers the photogenerated charge, and the transferred photogenerated charge is read as an image signal by the reading unit.

For example, when a line sensor is mounted on a scanner, a plurality of line sensor chips that are semiconductor chips are arranged in a straight line. Therefore, various techniques for maintaining resolution and preventing image disturbance in the chip gap portion have been proposed for a plurality of line sensor chips arranged.

For example, in a plurality of line sensor chips arranged in a straight line, a first technique for shortening the distance between a pixel at the end of the chip and a neighboring pixel (for example, refer to the column of the prior art in Patent Document 1) A second technique is disclosed and proposed in which the entire pixel pitch is set to a pixel pitch slightly shorter than the reading pitch determined by the resolution standard (see, for example, Patent Document 1).

According to Patent Document 1, the first technique for shortening the distance between the pixel at the end of the chip and the adjacent pixel is to interpolate the gap between the chips, that is, the nonexistent pixel in the chip gap. Disturbance can be prevented, but there is a problem that the output of the pixel at the end becomes non-uniform. In order to solve this problem, a second technique has been proposed in which a plurality of pixels are arranged at a pitch slightly shorter than the reading pitch determined by the resolution standard.

Further, a third technique has been proposed in which the distance between one light receiving element at the end of the line sensor chip and the adjacent light receiving element is made longer than the distance between the light receiving elements other than the respective light receiving elements at both ends. (For example, refer to Patent Document 2). According to the third technique, the distance between the light receiving elements in the chip gap portion becomes longer than the distance between the other light receiving elements in the chip, and therefore, the pitch of the light receiving elements in the entire line sensor is rapidly increased. Continuity can be prevented.

Japanese Patent No. 3013189 (FIGS. 2 and 4) Japanese Patent Publication No. 7-79403

However, in the second technique, the nonuniformity of the output of the end pixels is improved, and the number of pixels of the entire line sensor is not reduced, but the image is disturbed in the chip gap portion. There is.

Further, according to the third technique, since there is no sudden discontinuity in the pitch of the light receiving elements,
Although the disturbance of the image is reduced, the light receiving element at the end has a problem that the disturbance of the image occurs as a result when it is damaged by a mechanical impact during dicing.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a line sensor that does not cause image distortion due to the presence of a chip gap.

The line sensor according to the present invention is a line sensor including a plurality of pixels arranged in a straight line, wherein the plurality of pixels includes a number corresponding to a resolution, and the plurality of pixels arranged in the straight line are included. A first pixel group provided in the central portion and having a pixel pitch shorter than the length corresponding to the pixel pitch calculated from the resolution and both sides of the central portion are provided, and the pixel pitch is calculated from the resolution. And a second pixel group that is longer than the length corresponding to the pixel pitch to be set.
According to such a configuration, it is possible to realize a line sensor that does not cause image disturbance due to the presence of the chip gap.

In the line sensor according to the aspect of the invention, it is preferable that the number of the plurality of pixels is equal to the number corresponding to the resolution.
According to such a configuration, a line sensor having the same resolution as the required resolution can be realized.

In the line sensor according to the aspect of the invention, it is preferable that the line sensor includes a third pixel group that is provided between the central portion and the both side portions and has a pixel pitch equal to a length corresponding to the pixel pitch calculated from the resolution. .
In the line sensor according to the aspect of the invention, the pixel pitch may be provided between the central portion and the both side portions, and the pixel pitch may be shorter than the length corresponding to the pixel pitch calculated from the resolution, and may correspond to the pixel pitch of the central portion. It is desirable to have a third pixel group longer than the length.
In the line sensor according to the aspect of the invention, the pixel sensor is provided between the central portion and the both side portions, and the pixel pitch is longer than the length corresponding to the pixel pitch calculated from the resolution and is larger than the pixel pitch of the both side portions. It is desirable to have a short third pixel group.
According to such a configuration, it is possible to realize a line sensor in which image disturbance due to the presence of the chip gap is further prevented.

The line sensor of the present invention is a line sensor including a plurality of pixels arranged in a straight line, wherein the plurality of pixels includes a number corresponding to a resolution, and the plurality of pixels arranged in the straight line includes The pixel pitch is provided so as to gradually increase from the central part to the both end parts of the plurality of pixels arranged in a straight line.
According to such a configuration, it is possible to realize a line sensor that does not cause image disturbance due to the presence of the chip gap.

In the line sensor according to the aspect of the invention, it is preferable that the pixel pitch is gradually increased by continuously changing from the central portion toward the both end portions.
In the line sensor according to the aspect of the invention, it is preferable that the pixel pitch gradually increases by gradually changing from the central portion toward the both end portions.
According to such a configuration, it is possible to realize a line sensor in which image disturbance due to the presence of the chip gap is further prevented.

The line sensor according to the present invention is a line sensor including a plurality of pixels arranged in a straight line, wherein the plurality of pixels includes a number corresponding to a resolution, and the plurality of pixels arranged in the straight line are included. A first pixel group provided in the central portion and having a pixel pitch shorter than the length corresponding to the pixel pitch calculated from the resolution and both sides of the central portion are provided, and the pixel pitch is calculated from the resolution. And a second pixel group having a length equal to the length corresponding to the pixel pitch.
According to such a configuration, it is possible to realize a line sensor that does not cause image disturbance due to the presence of the chip gap.

In the line sensor according to the aspect of the invention, the pixel pitch may be provided between the central portion and the both side portions, and the pixel pitch may be shorter than the length corresponding to the pixel pitch calculated from the resolution, and may correspond to the pixel pitch of the central portion. It is desirable to have a third pixel group longer than the length.
According to such a configuration, it is possible to realize a line sensor in which image disturbance due to the presence of the chip gap is further prevented.

An image information reading apparatus according to an embodiment of the present invention is an image information reading apparatus including the line sensor.
According to such a configuration, it is possible to realize an image information reading apparatus that does not cause image disturbance due to the presence of the chip gap of the line sensor.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
First, based on FIG. 1, the structure of the image information reading apparatus which is an electronic device in which the line sensor according to the present embodiment is used will be described. FIG. 1 is a configuration diagram showing the configuration of the image information reading apparatus according to the present embodiment. FIG. 2 is a schematic sectional view for explaining a reading mechanism of the image information reading apparatus shown in FIG.

As shown in FIG. 1, the image information reading device 1 has a line sensor unit 2. The line sensor unit 2 has a plurality of line sensor chips 4 arranged in a straight line in the longitudinal axis direction of the substrate 3 on an elongated plate-like substrate 3. Each of the plurality of line sensor chips 4 includes a plurality of light receiving elements (hereinafter also referred to as pixels). When the plurality of line sensor chips 4 are arranged in a straight line, the plurality of pixels are arranged in a straight line. It arrange | positions on the board | substrate 3 so that it may rank. The line sensor unit 2 is provided with a plurality of lenses 5. The plurality of lenses 5 are arranged on the line sensor chip 4 so that each lens is located at a position corresponding to each pixel of the line sensor chip 4. The plurality of lenses 5 is, for example, a plurality of SELFOC (registered trademark) lens arrays. Further, the line sensor unit 2 is provided with an elongated lamp 6 as a light source device. On the substrate 3, a plurality of line sensor chips 4 are provided.
Is provided with an output circuit 7 for sequentially outputting image signals from the image signal to an external image signal processing circuit (not shown).

A conveyance device (not shown) is provided in the image information reading device 1, and the line sensor unit 2 can be moved in a direction L <b> 1 orthogonal to the longitudinal axis direction of the substrate 3 by the conveyance device. As the line sensor unit 2 moves, the reflection of image information placed on a transparent plate (not shown) such as a glass plate of the image information reading apparatus 1 from the surface of the paper 11 that is a medium to be read. A plurality of line sensor chips 4 arranged in a straight line receive light.

As shown in FIG. 2, the light from the lamp 6 is reflected by the surface of the paper 11, and the line sensor unit 2 receives the reflected light from the paper 11 through the lens 5 by the plurality of line sensor chips 4, while the paper 11 It moves along a predetermined direction L1 while maintaining a predetermined distance from the image information recording surface. As a result, the line sensor unit 2 can read image information while scanning the paper 11.

FIG. 3 is a schematic plan view for explaining the configuration of the line sensor chip 4. Each line sensor chip 4 has a plurality of light receiving elements, that is, a plurality of image elements 21. Multiple pixels 2
1 are arranged and formed on the surface of the line sensor chip 4 in a line, that is, in a straight line, with different intervals as will be described later. Arranging in a straight line includes not only arranging the pixels in one row but also arranging the pixels in three rows. When the pixels are arranged in three rows, white light is irradiated and read as an RGB sensor.

Further, the line sensor chip 4 includes a timing generator (TG) 22 as a timing signal generation circuit, a drive circuit 23 for driving each pixel 21, and a scanning circuit 24 that scans and reads out a pixel signal from each pixel 21. And an amplifier 25 that amplifies and outputs the pixel signal from the scanning circuit 24. An output signal from the amplifier 25 is supplied to the output circuit 7 described above.

Therefore, in the image information reading device 1, various control signals from a control unit (not shown) are supplied to the line sensor unit 2 and a transport device (not shown). The line sensor unit 2 that receives the various control signals internally generates a predetermined control signal, drives each line sensor chip 4, reads out and outputs an image signal. As a result, the image information reading apparatus 1 can read the image information on the paper 11.

Next, the pixel arrangement in each line sensor chip 4 will be described. FIG. 4 is a diagram for explaining pixel intervals in one line sensor chip 4. As shown in FIG.
On the line sensor chip 4, n pixels are arranged in a straight line in the scanning direction.

n is an integer and is a number determined by the resolution. Therefore, the number of pixels of each line sensor chip 4 can be ensured according to the resolution. In the following description, the number of pixels of each line sensor chip 4 is the number corresponding to the resolution, but at least the number corresponding to the resolution may be included and may be equal to or greater than the number calculated from the resolution. . This is because the number of pixels of each line sensor chip 4 may be determined in consideration of pixel defects in the chip gap.

Therefore, in this specification, the number according to the resolution is not only the same as the number of pixels calculated from the resolution, but also the number of pixels lost due to the chip gap in one chip to the number of pixels calculated from the resolution. When the number of pixels to be compensated is added, the number includes more than the number of pixels calculated from the resolution. When the number of pixels is the number corresponding to the required resolution, the line sensor chip 4 becomes a line sensor having the same resolution as the required resolution.

The surface of the line sensor chip 4 on which the plurality of pixels are provided has a rectangular shape, and the n pixels arranged in the scanning direction have a pixel pitch in the pixel group in the predetermined range R2 in the center. The pixel pitches in the pixel groups in the predetermined ranges R1 and R3 on both sides of the central range R2 are shorter than the standard pitch, and are arranged so as to be longer than the standard pitch.

Specifically, the pixel pitch is the distance between the centers of the photodiode formation regions of each pixel. The standard pitch PS is an image reading pitch determined by the resolution standard, and is a so-called regular arrangement pitch. As shown in FIG. 4, the pixel pitches P1 and P3 in the ranges R1 and R3 on both sides of the n pixels are longer than the standard pitch PS, that is, a wider pitch.
The pixel pitch P2 in the range R2 between the two ranges R1 and R3 is shorter or narrower than the standard pitch PS.

When n pixels are lined up from one end to the other, k pixels (k is an integer smaller than n) from 21 ₁ to 21 _k pixel groups In the range R1, the pixel pitch is the pixel pitch P1. Similarly, a pixel group from the (k−1) th pixel (that is, the (n− (k−1)) _th pixel) 21 _n to 21 _{(n− (k−1))} from the other end. In the range R3, the pixel pitch is the pixel pitch P3. Here, the pixel pitches P1 and P3 are equal and longer than the standard pitch PS. The pixel group from the kth pixel 21 _k to 21 _{(n− (k−1))} from one end has a pixel pitch P2 in the range R2 and is larger than the standard pitch PS. short.

For example, when the resolution is 1200 dpi (dots per inch), the standard pixel pitch PS is 21.17 μm. In the present embodiment, in the ranges R1 and R3, the pixel pitch P
1, P3 is 22.40 μm (> standard pitch PS), and in the range R2, the pixel pitch P2
Is 19.30 μm (<standard pitch PS).

In an apparatus equipped with a line sensor, an optical system that changes the image magnification, such as a reduction optical system, may be provided between a reading target and the line sensor. In such a case, the pixel pitch on the line sensor chip 4 is not equal to the pixel pitch calculated by the resolution, and is a pitch that is enlarged or reduced according to such an optical system. Therefore, on the line sensor chip 4, the standard pitch PS and the pixel pitch are determined on the basis of the length corresponding to the pixel pitch calculated from the resolution, taking into account the magnification of such an optical system. In the present embodiment and the second embodiment, the case where the standard pitch PS is equal to the pixel pitch calculated from the resolution will be described.

Next, the chip gap portion will be described.
FIG. 5 is a diagram for explaining a gap between two adjacent line sensor chips 4.
As shown in FIG. 5, each line sensor chip is cut by dicing or the like when manufactured. The diced line sensors are arranged so that the pixels are linear, and the end pixels 21 ₁ and 21 _n are the end pixels 21 _n and 2 of the adjacent line sensor chip 4, respectively.
It will be next to 1 ₁ .

With the recent increase in resolution, the pixel pitch tends to decrease. However, since the individual line sensor chips 4 are manufactured by being cut by dicing or the like, the gap length between chips (hereinafter referred to as a chip gap) G is larger than the pixel pitch.

For example, in FIG. 5, the resolution is 1200 dpi, the chip gap G is 30 μm to 50 μm due to the unevenness of the cut surface of the chip end, and the distance g from the chip end to the pixel end is 5
From μm to 10 μm. As a result, the distance (G + 2g) between the end pixels 21 ₁ and 21 _n is
From 40 μm to 70 μm, which is larger than the standard pitch PS (21.17 μm).

When the second and third techniques described in the related art are used, when the distance between the pixels in the gap portion is large as described above, image disturbance becomes conspicuous. However, in the case of the pixel pitch according to the present embodiment, the pixel pitches P1 and P3 at the end of the chip are longer than the standard pitch PS and shorter than the inter-pixel distance (G + 2g) in the gap, thereby causing image distortion. Can be inconspicuous.

That is, in this embodiment, in order to maintain the number n of pixels according to the resolution, the pixel pitch in the central pixel group is shortened, and the pixel pitch in the pixel groups on both sides is made longer than the standard pitch. A plurality of pixels are arranged on the line sensor chip 4. As a result, according to the present embodiment, the pixel group on both sides has a long pixel pitch, so that the disturbance of the gap image is not noticeable, and the pixel group in the central part is shortened to meet the resolution. This has the effect of ensuring the number of pixels.

Next, a modified example will be described.
6 to 9 are diagrams for explaining the first to fourth modifications. In the embodiment described above, a plurality of pixels are divided into three pixel groups, and there are two types of pixel pitches. In the following modification example, as shown in FIGS. 6 to 9, a plurality of pixels arranged in a straight line in one line sensor chip 4 are arranged in a plurality of regions along the scanning direction, here five regions R11. , R12,
There are three types of pixel pitches divided into R13, R14, and R15 pixel groups. In the following modification, five regions have three types of pixel pitches, but a larger number of regions and more types of pixel pitches may be used. According to the first to fourth modifications, it is possible to realize a line sensor in which image disturbance due to the presence of the chip gap is less generated.

As a first modification shown in FIG. 6, the pixel pitch in the pixel group of each region is set to a pixel pitch P13 (<PS) shorter than the standard pitch PS in the central region R13, and is adjacent to the central region R13. In the regions R12 and R14, the pixel pitches P12 and P14 are equal to the standard pitch PS.
(= PS), and regions outside the regions R12, R14 (ie, the outermost regions) R11, R1
5 is a pixel pitch P11, P15 (> PS) longer than the standard pitch PS. Even if it arranges in this way, the same effect as an embodiment mentioned above will arise.

Further, as a second modification shown in FIG. 7, the pixel pitch in the pixel group of each region is set such that the pixel pitch P1 is shorter than the standard pitch PS in the regions R12 and R14 adjacent to the central region R13.
2 and P14 (<< PS), and in the central region R13, the pixel pitch P13 (<< PS) is shorter than the standard pitch PS and shorter than the pixel pitches P12 and P14.
, R14 (ie, outermost regions) R11 and R15 have pixel pitches P11 and P15 (> PS) longer than the standard pitch PS. Even if it arranges in this way, the same effect as an embodiment mentioned above will arise.

Further, as a third modification shown in FIG. 8, the pixel pitch in the pixel group of each region is set to a pixel pitch P13 (<PS) shorter than the standard pitch PS in the central region R13, and the central region R13 In adjacent regions R12 and R14, the pixel pitch P12 is longer than the standard pitch PS.
, P14 (> PS), and the region outside the regions R12, R14 (ie, the outermost region) R
11 and R15, the pixel pitches P11 and P15 (>> PS) are longer than the standard pitch PS and longer than the pixel pitches P12 and P14. Even if it arranges in this way, the same effect as an embodiment mentioned above will arise.

Furthermore, as a fourth modified example shown in FIG. 9, a plurality of pixels may be arranged so that the pixel pitch gradually increases, that is, widens from the center of the line sensor chip 4 toward both ends.
That is, the central pixel pitch is set to a central pixel pitch PC (<<
PS), and the pixel pitch PP at both ends is longer than the standard pitch (>>).
PS), and the pixels may be arranged so that the pixel pitch gradually increases from the center toward both ends.

As a method of arranging a plurality of pixels so that the pixel pitch gradually increases from the central portion toward both ends, the method in which the pixel pitch gradually increases by continuously changing from the central portion toward both ends. In other words, there is a method in which the pixel pitch is gradually increased by changing stepwise, that is, discontinuously from the center to both ends. Even if it arranges in this way, the same effect as an embodiment mentioned above will arise.

As described above, in this embodiment, in a plurality of pixels arranged in a straight line, the pixel pitch of the central pixel group is made shorter than the standard pitch PS, and the pixel pitches of the pixel groups located on both sides thereof are standard. Shorter than the pitch PS. By arranging a plurality of pixels in such an array state, on one chip, the number n of pixels corresponding to the resolution is secured and the resolution is maintained, and the disturbance of the image in the gap portion between adjacent chips is reduced. it can.

Therefore, according to the present embodiment and each of the modified examples, when a plurality of line sensors are arranged, a line that does not cause image disturbance due to the presence of the chip gap and can secure the number of pixels corresponding to the resolution. A sensor can be realized.

(Second Embodiment)
Next, a second embodiment will be described.
In the second embodiment, in a plurality of pixels arranged in a straight line, the pixel pitch of the central pixel group is shorter than the standard pitch PS, and the pixel pitch of the pixel groups on both sides is equal to the standard pitch PS. To do. By arranging a plurality of pixels in such an array state, the number of pixels corresponding to the resolution can be maintained and the resolution can be maintained on one line sensor chip, and the pixel pitch can be changed from the center to both sides on one chip. In this way, the disturbance of the image in the gap portion between adjacent chips can be reduced. In this embodiment, by smoothing the resolution difference, the image disturbance in the gap portion between adjacent chips is made inconspicuous.

Since the second embodiment differs from the first embodiment only in the pixel pitch in each pixel group, the same components as those in the first embodiment are described using the same reference numerals. Omitted.
FIG. 10 is a diagram for explaining pixel intervals in the line sensor chip 4 according to the second embodiment. As shown in FIG. 10, the pixel pitch P22 in the pixel group in the central range R22 is shorter than the standard pitch PS, and the pixel pitches P21 and P23 in the respective pixel groups in the ranges R21 and R23 on both sides of the central portion are as follows. Standard pitch PS.

For example, in the pixel groups in the ranges R21 and R23, the pixel pitches P21 and P23 are 21.17.
In the pixel group in the range R22, the pixel pitch P22 is 19 μm (= standard pitch PS).
. 30 μm (<standard pitch PS).

By arranging a plurality of pixels so as to have such a pixel pitch, each line sensor chip 4 includes more than the number of pixels corresponding to the resolution. An image signal can be obtained.

Further, since the pixels of the pixel groups on both sides with respect to the central part are longer than the pixel pitch of the central pixel group, the pixel pitch gradually increases from the central part to the gap part via both side parts. To change. Therefore, the disturbance of the image in the gap portion between the adjacent chips can be made inconspicuous.

Next, a modified example will be described.
FIG. 11 is a diagram for explaining a first modification of the second embodiment. Here, as shown in FIG. 11, a plurality of pixels arranged in a straight line in one line sensor chip 4 are
Along the scanning direction, a plurality of regions, here five regions R31, R32, R33, R34
, R35.

As shown in FIG. 11, the pixel pitches of the pixel groups in the respective regions are set to pixel pitches P32 and P34 (<PS) which are shorter than the standard pitch PS in the regions R32 and R34 adjacent to the central region R33.
) In the central region R33 and shorter than the standard pitch PS and the pixel pitches P32 and P3
A pixel pitch P33 (<< PS) that is shorter than 4 is set, and a standard pitch PS is set in the regions R31 and R35 outside the regions R32 and R34 (that is, the outermost regions) R31 and R35. Even if arranged in this way, the same effects as those of the second embodiment described above are produced.

Further, as a second modification, a plurality of pixels may be arranged so that the pixel pitch gradually increases, that is, widens from the center portion of the line sensor chip 4 toward both ends. The second modification will be described with reference to FIG. 9. The central pixel pitch is set to a central pixel pitch PC (<< PS) shorter than the standard pitch, and both end pixel pitches are set to the standard pitch PS. The pixels may be arranged so that the pixel pitch gradually increases from the center toward both ends.

As in the fourth modification of the first embodiment, as a method of arranging a plurality of pixels so that the pixel pitch gradually increases from the center toward both ends, the pixel pitch is changed from the center to both ends. There are a method in which the pixel pitch is gradually increased by continuously changing toward the part, and a method in which the pixel pitch is gradually increased in a stepwise manner, that is, discontinuously, from the central part toward both ends. Even if arranged in this way, the same effects as those of the second embodiment described above are produced.

As described above, according to each embodiment of the present invention, when a plurality of line sensors are arranged, the number of pixels corresponding to the resolution is secured so as not to cause image disturbance due to the presence of the chip gap. A possible line sensor can be realized. If the line sensor chip according to the above-described two embodiments is used in an image information reading apparatus such as a facsimile, an image reading apparatus that does not cause image distortion due to the presence of the chip gap of the line sensor is realized. Can do.
The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

1 is a configuration diagram showing a configuration of an image information reading apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view for explaining a reading mechanism of the image information reading apparatus shown in FIG. 1. FIG. 3 is a schematic plan view of the line sensor chip according to the first embodiment. Explanatory drawing of the pixel space | interval in the line sensor chip concerning 1st Embodiment. The figure for demonstrating the gap of two adjacent line sensor chips. The figure for demonstrating the 1st modification of the line sensor which concerns on 1st Embodiment. The figure for demonstrating the 2nd modification of the line sensor which concerns on 1st Embodiment. The figure for demonstrating the 3rd modification of the line sensor which concerns on 1st Embodiment. The figure for demonstrating the 4th modification of the line sensor which concerns on 1st Embodiment. The typical top view of the line sensor chip concerning a 2nd embodiment. The figure for demonstrating the modification of the line sensor which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image reader, 2 ... Line sensor unit, 3 ... Board | substrate, 4 ... Line sensor chip,
DESCRIPTION OF SYMBOLS 5 ... Lens, 6 ... Lamp, 7 ... Output circuit, 11 ... Paper, 21 ... Light receiving element (pixel), 22 ... Timing generator, 23 ... Drive circuit, 24 ... Scan circuit, 25 ... Amplifier.

Claims (11)

A line sensor including a plurality of pixels arranged in a straight line,
The plurality of pixels includes a number according to resolution,
A first pixel group provided at a central portion of the plurality of pixels arranged in a straight line and having a pixel pitch shorter than a length corresponding to a pixel pitch calculated from the resolution;
And a second pixel group that is provided on both sides of the central portion and has a pixel pitch longer than a length corresponding to the pixel pitch calculated from the resolution. The number of the plurality of pixels is equal to the number according to the resolution.
The described line sensor. 2. A third pixel group, which is provided between the center portion and the both side portions, and has a pixel pitch equal to a length corresponding to a pixel pitch calculated from the resolution.
Or the line sensor of 2. A third pixel provided between the central portion and the both side portions, wherein the pixel pitch is shorter than the length corresponding to the pixel pitch calculated from the resolution and longer than the length corresponding to the pixel pitch of the central portion; The line sensor according to claim 1, wherein the line sensor includes: A third pixel provided between the central portion and the both side portions, the pixel pitch being longer than the length corresponding to the pixel pitch calculated from the resolution and shorter than the pixel pitch of the both side portions;
The line sensor according to claim 1, wherein the line sensor includes: A line sensor including a plurality of pixels arranged in a straight line,
The plurality of pixels includes a number according to resolution,
The plurality of pixels arranged in a straight line are provided such that a pixel pitch gradually increases from a central portion toward both ends of the plurality of pixels arranged in a straight line. Line sensor. The line sensor according to claim 6, wherein the pixel pitch is gradually increased by continuously changing from the central portion toward the both end portions. The line sensor according to claim 6, wherein the pixel pitch is gradually increased by changing stepwise from the central portion toward the both end portions. A line sensor including a plurality of pixels arranged in a straight line,
The plurality of pixels includes a number according to resolution,
A first pixel group provided at a central portion of the plurality of pixels arranged in a straight line and having a pixel pitch shorter than a length corresponding to a pixel pitch calculated from the resolution;
And a second pixel group provided on both sides of the central portion and having a pixel pitch equal to a length corresponding to a pixel pitch calculated from the resolution. A third pixel provided between the central portion and the both side portions, wherein the pixel pitch is shorter than the length corresponding to the pixel pitch calculated from the resolution and longer than the length corresponding to the pixel pitch of the central portion; The line sensor according to claim 9, wherein the line sensor includes: An image information reading apparatus including the line sensor according to claim 1.

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