JPH10336407A - Line sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To receive an image without color smear by selecting an interval of the same pixel lines to be a specific multiple of a vertical pixel pitch of each pixel line. SOLUTION: The line sensor 1 reads three lines, 1st, 2nd and 3rd pixel lines for the movement of one line in the vertical direction. An interval d1 of the 1st pixel lines 11 is selected to be a multiple of (an integer +1/3) of a pixel pitch p1 in the vertical direction in each of the 1st-3rd pixel lines. Thus, a position of an original corresponding to a 2nd output of the 1st-pixel line 11b is deviated from a position of the original corresponding to a 1st output of the 1st-pixel line 11b by an interval of a multiple of 1/3 of the pixel pitch P1 in the vertical direction. Since an image is picked up when it is deviated by a multiple of (an integer +1/3) of the pixel pitch p1 through sequential read of the 1st-3rd pixel lines in a conventional processing system, the line sensor 1 corrects the deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line sensor, and more particularly, to a line sensor in which sensor units are arranged in a horizontal line.

[0002]

2. Description of the Related Art Line sensors R [red], G [green], B
The arrangement interval of each pixel line of [blue] is an integral multiple of the pixel size in the vertical direction, where the pixel arrangement direction of each pixel line is the horizontal direction. In other words, it is also an integral multiple of the vertical pixel pitch. Therefore, theoretically, every time the head or the subject of the scanner is moved by the pixel size (pixel pitch), the head or the subject is stopped and
What is necessary is just to read the color line.

[0003]

However, in practice, the time positions for reading out the R, G, and B pixel lines are different, and each time the head or subject is moved by one pixel size. When the head or the subject cannot be completely stopped, the head or the subject moves at a substantially constant speed, and a color shift occurs due to a shift in a spatial position for reading in each of the R, G, and B pixel lines. I was In the dot sequential method in which the R, G, and B pixel lines are read at once, the above-described color shift does not occur, but a device for processing the output signal of the line sensor needs to be provided for each pixel line. Therefore, the cost was increasing.

Here, the color shift will be described. The color misregistration is a phenomenon in which a color is added to a boundary between white and black in an image in which colors are captured. As shown in FIG. 3, the distance d between the R, G, and B pixel lines 111 of the line sensor 101 (the target pixel line is indicated by oblique lines in the drawing) is the pixel pitch [=
Pixel size] is an integral multiple of p [n times]. As shown in FIG. 4, while the image 121 moves in the direction indicated by the arrow A by the length of one pixel [the length indicated by the arrow A] by the line sensor 111, each of the R, G, and B pixel lines 111R is sequentially arranged. , 11
Reading of 1G and 111B is performed. In FIG. 4, the vertical axis indicates the output, and the horizontal axis indicates the time. As a result, a position where the image is shifted by (integer + ／) times the pixel is captured. In this readout, an image is taken each time the pixel is moved by one pixel, so that a shift of an integer multiple of the pixel size can be corrected using a line memory or the like in the subsequent processing, but a shift such as 1/3 of the pixel size can be corrected. It was difficult to correct.

[0005]

According to the present invention, there is provided a line sensor for solving the above-mentioned problems. That is,
A line sensor that has a pixel line in which pixels are arranged in a horizontal direction and linearly. In a line sensor that reads m lines each time it moves one line in the vertical direction, a pixel line of the same type as the m line pixel lines Is (integer + 1 /) of the vertical pixel pitch in the m pixel lines.
m) It is set to be twice as long. For example, m = 3 pixels in a first pixel line [for example, an R pixel line], a second pixel line [for example, a G pixel line], and a third pixel line [for example, a B pixel line]. If the pixel line is provided with the line, the interval between the first pixel lines, the interval between the second pixel lines, and the interval between the third pixel lines are (integer + 1 / m) times = (integer + ／) times the length.

In the above line sensor, the interval between the m pixel lines and the same type of pixel line is (integer + 1 / m) of the vertical pixel pitch of the m pixel lines.
Since the length is set to twice = (integer + ／) times, for example, the distance between the first pixel lines, the distance between the second pixel lines, and the distance between the third pixel lines are equal to the above three lines. Is set to (integer + ／) times the vertical pixel pitch in the pixel line of. For this reason, for example, the line interval is set so that the original document line read by the first pixel line of the first pixel line has a length (integer + 倍) times the pixel size in the vertical direction from the first pixel line. The second first pixel line reads. Therefore,
The document portion corresponding to the output of the second first pixel line is shifted from the document portion corresponding to the output of the first first pixel line by 1/3 times the pixel size in the vertical direction. . However, in the conventional case where the interval between the first pixel lines is an integral multiple of the pixel size in the vertical direction, the first to third pixel lines are sequentially read while the image is moved by the length of one pixel pitch by the line sensor. Is performed, an image is taken at a position where the image is shifted by (integer + ／) times of the pixel. Therefore, in the line sensor of the present invention,
The deviation will be corrected. Therefore, color shift is suppressed. Similarly, the color shift of the second pixel line and the third pixel line is also suppressed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the first embodiment of the present invention will be described below.
This will be described with reference to the schematic configuration diagram of the main part of FIG. In FIG.
A line sensor having three lines of R, G, and B will be described.

As shown in FIG. 1, a line sensor 1
Elements 21 are arranged horizontally and linearly.
The first pixel line [for example, the R pixel
Line] 11 and the pixels are not indicated on the drawing, but the pixels
A second pixel line [e.g.,
G pixel line] and pixels are arranged in a horizontal and linear manner.
A third pixel line [for example, a B pixel line]
And This line sensor 1 has one line in the vertical direction.
The first pixel line 11 and the second pixel line
And the third pixel line are read out.
Swelling. Further, the distance between the first pixel lines 11
d₁Are vertical pixels in the first to third pixel lines
Pitch p₁(Integer + 1/3) times as long as integer
To n₁As (n₁+1/3) p₁Is set to
You. Here, pixel size and pixel pitch p₁Is equivalent to
ing. Although not shown, between the second pixel lines
Interval d _TwoRepresents the vertical image in the first to third pixel lines.
Raw pitch p_Two[= P₁] (Integer + ／) times as long,
That is, the integer is n_TwoAs (n_Two+1/3) p_TwoSet in
Is defined. Also, the distance d between the third pixel lines_ThreeIs
Vertical pixel pitch p in the first to third pixel lines
_Three[= P₁] (Integer + ／) times, ie, integer
Number n_ThreeAs (n_Three+1/3) p_ThreeIs set to
You. Here, pixel size and pixel pitch p_Two, P_ThreeAnd the same
And so on. In other words, the line sensor 1
Each interval d₁, D_Two, D_ThreeThe conventional line sensor
Length of (integer + ／) times the pixel pitch in the direction
It is.

In a head or subject (not shown) of a scanner using the line sensor 1, while reading out three lines, for example, first, second, and third pixel lines of R, G, and B, the head or subject is imaged at an image forming position. The imaging is performed by moving the pixel 21 at a constant speed so as to move by the vertical length of the pixel 21 at a distance of. The output of the line sensor is processed in the same manner as the conventional line-sequential system. For example, a three-line CCD [Charge-Coupled Device] linear sensor clock signal is received from a digital signal processing unit and the sensor output is performed. The processing may be performed by, for example, an analog signal processing unit.

In the line sensor 1, since the interval d ₁ between the first pixel lines 11 is set to be (integer + ／) times the pixel pitch p _{1 in} the vertical direction, the original location of the pixel lines 11a has read the beginning of 11 from the first pixel line 11a of the beginning of the vertical pixel pitch p ₁ (integer +1/3) multiple of the length to the second set of line spacing d ₁ The first pixel line 11b reads. Therefore, the document portion corresponding to the output of the second first pixel line 11b is located at a pixel pitch p _{1 in the} vertical direction with respect to the document portion corresponding to the output of the first first pixel line 11a.
Will be shifted by 1/3 times the length of. However, in the conventional case where the interval between the first pixel lines is an integral multiple of the pixel size in the vertical direction, the first to first pixels are sequentially moved while the image moves by the length of one pixel pitch (= 1 pixel size) by the line sensor. By reading out the third pixel line, an image is taken at a position shifted by (integer + ／) times the pixel pitch, so that the line sensor 1 of the present invention corrects the shift. Become. Therefore, color shift is suppressed. Similarly, the color shift of the second pixel line and the third pixel line is also suppressed.

Next, an example of the second embodiment will be described with reference to FIG. FIG. 2 shows a line sensor having two lines. In FIG. 2, FIG.
The same reference numerals are given to the same components as described in the above.

As shown in FIG. 2, the line sensor 2 is formed by arranging pixels 21 in a horizontal direction and linearly, and does not indicate a first pixel line 11 in an area shown by oblique lines in the drawing. And a second pixel line in which pixels are arranged in a horizontal direction and linearly. Each time the line sensor 2 moves one line in the vertical direction, the first pixel line 11
And reading of two lines of the second pixel line. Further, the distance d between the first pixel lines 11
₁ is defined as (n ₁ + ／) p ₁ , where n is a length of (integer + ／) times the vertical pixel pitch p ₁ of the first and second pixel lines, that is, n _1. I have. Here, the pixel pitch p ₁ is the equal to the pixel size. Although not shown, the distance d between the second pixel lines d
_2, first, (integer + 1/2) times the length of the pixel pitch p ₂ in the vertical direction in the second pixel line (= p _1), i.e. an integer as n _2, (n ₂ +1/3) p Set to ₂ . Pixel pitch p ₂ are equivalent to the pixel size. In other words, in the line sensor 2, each of the intervals d ₁ and d ₂ is set such that the vertical pixel pitch of the conventional line sensor is (integer + 整数) times as long.

In the head or subject (not shown) of the scanner using the line sensor 2, the head or subject is moved to the pixel 21 by the distance of the image forming position while two lines are read.
The image is taken by moving at a constant speed so as to move by the length in the vertical direction. The processing of the output of the line sensor may be performed by a method similar to the conventional line sequential method.

In the line sensor 2, the distance d ₁ between the first pixel lines 11 is set to be (integer +＋ _１ ) times the pixel pitch p _{1 in} the vertical direction. The second document line 11 in which the line interval d ₁ is set to a length of (an integer + ／) times the pixel pitch p _{1 in} the vertical direction from the first pixel line 11 a to the original document position read by the first pixel line 11 a of 11. The first pixel line 11b reads. Therefore, the document portion corresponding to the output of the second first pixel line 11b is located at a pixel pitch p _{1 in the} vertical direction with respect to the document portion corresponding to the output of the first first pixel line 11a.
Will be shifted by half the length of. However, in the conventional case where the interval between the first pixel lines is an integral multiple of the pixel size in the vertical direction, the first and second pixel lines are sequentially read while the image is moved by the length of one pixel size by the line sensor. Is performed, the image becomes (integer + 1) of the pixel.
/ 2) Since the image is taken at a position shifted by a factor of 2,
In the line sensor 1 of the present invention, the deviation is corrected. Therefore, color shift is suppressed. Similarly, the second
The color shift of the pixel line 12 is also suppressed.

In the above description, the case where m = 3 is described in the first embodiment, and the case where m = 2 is described in the second embodiment. However, the present invention is not limited to this. Also, the color shift can be corrected by making the pixel pitch interval times (integer + 1 / m) times. In addition, the first and second
In the line sensors 1 and 2 of the embodiment, the circuit from the sensor output to the digital signal processor can be reduced to about 1/3 the size of the line sensor of the dot sequential reading system. Further, the line sensors 1 and 2 of the first and second embodiments can be easily applied to a device that performs processing in a line-sequential manner.

[0016]

As described above, according to the present invention,
A line sensor that has a pixel line in which pixels are arranged in a horizontal direction and linearly, and in a line sensor that reads m lines each time it moves one line in a vertical direction, the distance between the pixel line and the same kind of pixel line However, since the length is set to (integer + 1 / m) times the pixel size in the vertical direction, it is possible to capture an image without color misregistration using the same processing system as a conventional line sequential type line sensor. become.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a main part of a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a main part of a conventional line sensor.

FIG. 4 is an explanatory diagram of a problem.

[Explanation of symbols]

1 ... line sensor, 11 ... first pixel line, 21 ... pixels, d ₁ ... intervals, p ₁ ... pixel size

Claims (3)

[Claims] 1. A line sensor comprising a pixel line in which pixels are arranged in a horizontal direction and linearly, and reading out m pixel lines every time one pixel moves in a vertical direction. The distance between the line and the same kind of pixel line is m
A line sensor characterized in that the length is set to (integer + 1 / m) times the vertical pixel pitch of the pixel lines. 2. The line sensor according to claim 1, further comprising a first pixel line, a second pixel line, and a third pixel line, wherein each of the first pixel line, the second pixel line, and the second pixel line moves in the vertical direction. The three lines of the third pixel line are read out, and the distance between the first pixel lines, the distance between the second pixel lines, and the distance between the third pixel lines are equal to the vertical pixels in the three lines. Pitch (integer + 1 /
3) A line sensor which is set to be twice as long. 3. The line sensor according to claim 1, wherein the line sensor includes a first pixel line and a second pixel line, and each time the first pixel line and the second pixel line move one line in the vertical direction. Two lines are read out, and the interval between the first pixel lines and the interval between the second pixel lines are set to (integer + ／) times the vertical pixel pitch of the two lines. A line sensor characterized in that: