JPH06311302A - Color solid-state line sensor - Google Patents

Abstract

PURPOSE:To read a picture with color separation and to obtain picture data with high quality without coloring with respect to a black/white picture by arranging two line sensors providing an output of each color signal side by side to a common board. CONSTITUTION:Light receiving element arrays 20c, 20d comprising plural light receiving elements 20b arranged on a common board 20a are formed to the color solid-state line sensor 20. Red, green and blue color filters are vapor- depositted periodically in the line direction in each element 20b of the array 20c to form light receiving sections 21, 22, 23 of each color. Furthermore, an infrared ray filter is vapor-depositted to each element 20b of the array 20d and the infrared ray receiving section 24 is formed. Then the light receiving sections 21, 22, 23 read a color picture in an original while separating the color picture in the original into three colors of red, green and blue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image reading device for reading a color image and a black and white image, and more particularly to high quality image data for both the color image and the black and white image used in this color image reading device. The present invention relates to a color solid line sensor capable of obtaining

[0002]

2. Description of the Related Art Generally, in a color image reading apparatus, an original image is scanned by a color solid line sensor, and the original image is separated into three primary color components of red, green and blue to read image information. .

FIG. 8 is a schematic configuration diagram showing a configuration example of a general color image reading apparatus. In the color image reading device 80 shown in FIG. 8, the original 12 placed on the platen glass 13 is fixed on the platen glass 13 by the original pressing member 11. Scan imaging unit 14
Is a halogen lamp 15, a reflector 16, a light blocking member 17,
It is composed of a short focus lens array 18, an infrared cut filter 81, and a color solid line sensor 82, and reads the original 12 while moving in the direction of arrow A in FIG.

In the scanning image forming unit 14, the reflected light of the original 12 illuminated by the halogen lamp 15 is imaged on the color solid line sensor 82 by the short focus lens array 18. An infrared cut filter 81 is provided in the optical path reaching the color solid line sensor 82.

FIG. 9 is a plan view showing a structural example of the color solid line sensor 82. A light receiving element array 82c including a plurality of linearly arranged light receiving elements 82b, 82b, ... Is formed on the substrate 82a.
b, 82b, ... Red (R), green (G) and blue (B) filters are periodically arranged, and light receiving portions 83, 84 and 85 corresponding to the respective colors of red, green and blue are provided. Has been formed. Then, a red image signal, a green image signal and a blue image signal are obtained from the light receiving portions 83, 84 and 85 of the respective colors.

[0006]

However, in the color image reading apparatus as shown in FIG. 8, when the color solid line sensor 82 in which the light receiving portions of respective colors are periodically arranged as shown in FIG. 9 is used, There is a problem that it is difficult to read a black character original with high quality. The reasons are as follows.

In a color image reading apparatus as shown in FIG. 8, red, green and blue are used for color originals.
Image information is read after color separation, and red, green, and blue image signals are output. For black and white manuscripts,
When it is known in advance that the original is a monochrome original, for example, a monochrome original reading mode is set and a green image signal is output as a monochrome image signal. However, when reading a document in which color images and black-and-white images are mixed, the black-and-white images are separated into three colors of red, green, and blue to read the image information, and the red, green, and blue images are read. It is necessary to reproduce a black and white image from the signal.

However, as shown in FIG. 9, a color solid line sensor 82 in which light receiving portions of respective colors are periodically arranged.
When using, the thin black line is read due to the difference in the image forming performance of the optical system for each color and the deviation of the pixel position in the line direction (main scanning direction) of the three colors of red, green and blue. There is a problem that the image is colored.

Further, in the color image reading apparatus as shown in FIG. 8, a color solid line sensor 8 in which three rows of light receiving portions corresponding to respective colors are arranged as shown in FIG.
6 may be used.

In the color solid-state line sensor 86 shown in FIG. 10, a plurality of light receiving elements 86b, 86b, ...
Book light receiving element rows 86c, 86d, 86e are formed, and the light receiving elements 86b, 8 of each row 86c, 86d, 86e are formed.
6b, ..., Red, green, and blue filters are arranged for each column, and light receiving portions 87, 8 corresponding to the respective colors of red, green, and blue are provided.
8, 89 are formed. Then, the red image signal, the green image signal, and the blue image signal are obtained from the light receiving units 87, 88, 89 of the respective colors.

However, even when the color solid-state line sensor 86 in which three rows of light receiving portions corresponding to each color are arranged as shown in FIG. 10 is used, the difference in the image forming performance of the optical system for each color and the red color. , Moving direction of the scanning and imaging unit 14 when reading in three colors of green and blue (sub scanning direction)
There is a problem that the image obtained by reading the black fine line is colored due to the deviation of the line.

An image reading apparatus which obtains image data of a black portion in document information by color-separating infrared light from reflected light from a document is disclosed in Japanese Patent Laid-Open No. 4-834.
Although it is known in Japanese Patent Laid-Open No. 64, only the information of black-and-white image and specific color image is obtained because the apparatus described in that publication only performs color separation by a prism and detects reflection components at two different wavelengths. It is not possible to read a normal color image.

Therefore, an object of the present invention is to solve the above problems, and when a color image reading apparatus reads an original in which a color image and a black-and-white image are mixed, the color image can be color-separated and read. An object of the present invention is to provide a color solid-state line sensor that can obtain high-quality image data without coloring to an image.

[0014]

The color solid-state line sensor of the present invention separates the components of the input light into three colors of red, green and blue on a common substrate to obtain red, green and blue color signals. And a second line sensor that detects an infrared component of the input light and outputs an infrared signal are arranged adjacent to each other.

[0015]

The reflected light from the document is commonly applied to the first line sensor and the second line sensor. The first line sensor separates the components of the input light into three colors of red, green and blue and outputs red, green and blue color signals. Therefore,
A color image signal is obtained by reading the color image. Further, the second line sensor detects the infrared component of the input light and outputs an infrared signal. Since the black ink used for printing absorbs infrared light and the other color inks reflect infrared light, a black image can be detected by detecting the magnitude of the infrared component of the input light. When reading a document in which color images and black-and-white images are mixed, high-quality image data without coloring can be obtained by obtaining black-and-white image data from the second line sensor.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments with reference to the drawings.

FIG. 1 is a schematic sectional view showing a structural example of a color image reading device to which the color solid line sensor of the present invention is applied. Color image reading apparatus 1 shown in FIG.
0, the original document 1 placed on the platen glass 13
The document 2 is fixed on the platen glass 13 by the document holder 11. The scanning / imaging unit 14 includes a halogen lamp 15, a reflector 16, a light blocking member 17, a short focus lens array 18, an infrared cut filter 19, and a color solid line sensor 20, and the direction of arrow A in FIG. The original 12 is read while moving to.

In the scanning image forming unit 14, the reflected light of the original 12 illuminated by the halogen lamp 15 is imaged on the color solid line sensor 20 by the short focus lens array 18. The infrared cut filter 1 is provided at a position that blocks part of the optical path reached by the color solid line sensor 20.
9 is provided.

FIG. 2 is a plan view showing a first embodiment of the color solid line sensor of the present invention. As shown in FIG. 2, the color solid-state line sensor 20 shown in FIG.
Two light-receiving element arrays 20c, 2 composed of b, 20b, ...
0d is formed. The red, green, and blue filters are periodically vapor-deposited in the line direction on the respective light receiving elements 20b, 20b, ... Of the one light receiving element row 20c, and the light receiving portions 21, 22, 22 of the respective colors of red, green, and blue are provided. 23 is formed. In addition, each of the light receiving elements 20b, 20 of the other light receiving element array 20d
An infrared filter is vapor-deposited on b, ..., And an infrared light receiving portion 24 is formed. Each red, green and blue light receiving part 2
1, 22, 23 and the infrared light receiving section 24 have a length of 42 μm in the short side direction and the long side direction of the line sensor 20, and each of the red, green, and blue light receiving sections 21, 22, 22. Two
One cycle of repeating 3 is 128 μm in the long side direction of the line sensor 20.

Therefore, the light receiving portions 21, 22, and 23 of the color solid line sensor 20 shown in FIG. 2 separate the color image in the original document into three colors of red, green and blue to obtain 200 spi.
It can be read at a resolution of (spot per inch). As shown in FIG. 1, the red, green, and blue light receiving portions 21, 22, 23 of the color solid line sensor 20.
An infrared cut filter 19 is provided in the optical path that reaches to prevent the infrared rays from irradiating the red, green and blue light receiving portions 21, 22, 23.

On the other hand, paying attention to the reflectance of infrared rays, the reflectance of the yellow, magenta and cyan inks forming the color image in the original document is high, and the reflectance of the black ink is low. That is, the black ink used for printing absorbs infrared light, and the other color inks reflect infrared light. Therefore, when the output of the infrared light receiving unit 24 is less than or equal to the predetermined threshold value, it can be determined that the image is a black image. Further, one infrared ray receiving unit 24 can detect one pixel. Therefore, the infrared light receiving unit 24 outputs the black information 6
It can be read at a resolution of 00 spi.

FIG. 3 is a block diagram showing a color copying machine using the color solid line sensor 20 shown in FIG. 1. This color copying machine is a color image reading apparatus 10.
Color solid line sensor 20, an image processing unit 30 that performs a predetermined image processing on the image output from the color solid line sensor 20, and a color image forming apparatus 40 that prints a color image on paper. ing.

The red light receiving section 21 of the color solid line sensor 20 produces a red output signal R, and the green light receiving section 22.
Produces a green output signal G, a blue light receiving portion 23 produces a blue output signal B, and an infrared light receiving portion 24 produces an infrared output signal IR. Four output signals R, G, B, IR from the color solid line sensor 20
Are respectively amplified by an amplifier (indicated by AMP in the figure) 31 and then a sample hold circuit (S / H in the figure).
After removing the reset noise by means of 32), A / D converters (shown by A / D in the figure) 33 respectively
Entered in. Next, the output of the A / D converter 33 is input to a resolution conversion circuit (indicated by SPI conversion in the figure) 34, and the red, green and blue signals are respectively converted to desired resolutions. For example, the resolution of red, green and blue signals is 20
It is converted from 0 spi to 600 spi and matched with the resolution of the infrared signal.

Next, the signals R, G, and B are each a gradation correction circuit (LUT in the figure) composed of a look-up table.
The gradation characteristics are corrected according to the reference numeral 35, and then input to the color correction circuit 36. In the color correction circuit 36, the color image forming apparatus 40 is responsive to the input signals R, G and B.
A yellow signal Y, a magenta signal M, a cyan signal C, and a black signal K for reproducing a color image are generated, and these signals Y, M, C, and K are input to the signal selection circuit 37.

The signal IR is subjected to correction of gradation characteristics by the gradation correction circuit 35 and then divided into two, one of which becomes a signal K2 for reproducing a black character in the color image forming apparatus 70, and a signal selection circuit. 37 is input. The other is input to the black line determination circuit 38.

The black line determination circuit 38 determines whether or not the input image signal is in the black line region, and inputs the determination result to the signal selection circuit 37. That is, when the level of the signal input to the black line determination circuit 38 is less than the predetermined threshold value, it is determined as a black line region.

When the determination result of the black line determination circuit 38 is the black line region, the signal selection circuit 37 outputs the signal K2, and when it is the non-black line region, the signal selection circuit 37 outputs the signals Y, M, C and K1.
Is output. The color image forming apparatus 70 forms an image according to the output signal of the signal selection circuit 37. Therefore, the color image forming apparatus 40 reproduces a color image with four colors of yellow, magenta, cyan, and black, and reproduces a black character and a black line drawing with one color of black to form a high-quality image without coloring. it can.

FIG. 4 shows a second embodiment of the color solid line sensor of the present invention. Also in the color solid line sensor 50 shown in FIG. 4, as in the first embodiment, the red, green and blue light receiving portions 51, 52 and 53 are periodically arranged at predetermined intervals in the longitudinal direction of the line sensor 50. The infrared light receiving portion 54 is arranged in parallel to the above. Light receiving part 5
Reference numeral 1 is a red filter, light receiving portion 52 is a green filter, light receiving portion 53 is a blue filter, and light receiving portion 54 is an infrared filter. Each of the red, green and blue light receiving portions 51, 52, 53 and the infrared light receiving portion 54 has a length of 64 μm in the short side direction of the line sensor 50.
One cycle of repetition of each of the red, green and blue light receiving portions 51, 52 and 53 is 64 μm in the long side direction of the line sensor 50. Further, the infrared light receiving section 54 has a length substantially equal to one cycle of the light receiving sections 51, 52, 53 in the short side direction of the line sensor 50, strictly speaking, an outer end portion of the red light receiving section 51 within one cycle. It has a length between the outer end of the blue light receiving portion 53.
That is, the red, green, and blue light receiving portions 51, 5 within one cycle
Reference numerals 2 and 53 correspond to one infrared ray receiving portion 54.

Therefore, according to the color solid-state line sensor 50 shown in FIG. 4, each of the red, green and blue light receiving portions 5 is included.
With 1, 52 and 53, the original can be separated into three colors of red, green and blue and read at a resolution of 400 spi. In addition, the infrared light receiving unit 54 transmits the black and white information at 400 sp
It can be read at a resolution of i.

This color solid line sensor 50 is shown in FIG.
The color solid-state line sensor 20 shown in FIG. However, in that case, in the circuit shown in FIG. 3, it is necessary to triple the processing cycle for the infrared signal IR.

In the above-mentioned first and second embodiments, the color solid-state line sensor in which the light receiving portions of each color are periodically arranged is used. However, as described below, the light receiving portions of each color are independently formed. It is also possible to use three color solid line sensors arranged.

Next, a third embodiment of the color solid line sensor of the present invention will be described with reference to FIG.

Color solid-state line sensor 6 shown in FIG.
No. 0 has four light receiving element rows 60c, 60d, 60e, 60f formed of a plurality of light receiving elements 60b, 60b, ... arranged linearly on the substrate 60a. A red filter is vapor-deposited on each of the light receiving elements 60b, 60b, ...
Green and blue filters are vapor-deposited on d and 60e, respectively, and light receiving portions 61, 62, and 62 corresponding to respective colors of red, green, and blue are deposited.
63 is formed. In addition, the remaining light receiving element array 60f
An infrared filter is vapor-deposited on the substrate, and a light receiving portion 64 that responds to infrared rays is formed. Red, green and blue light receiving parts 6
1, 62, 63 and the infrared light receiving section 64 have a length of 64 μm in the short side direction and the long side direction of the line sensor 60.

Therefore, the light receiving portions 61, 62 and 63 of the color solid line sensor 60 shown in FIG. 5 separate the color image in the original document into three colors of red, green and blue to 400 spi.
Can be read at a resolution of. Further, the infrared light receiving section 64 can read black and white information at a resolution of 400 spi.

FIG. 6 is a block diagram showing a color copying machine using the color solid line sensor 60 shown in FIG. 5, and this color copying machine has a color image reading apparatus 10.
The color solid line sensor 60, the image processing unit 30 that performs predetermined image processing on the image output from the color solid line sensor 60, and the color image forming apparatus 40 that prints a color image on paper. ing.

The red light receiving section 61 of the color solid line sensor 60 produces a red output signal R, and the green light receiving section 62.
Produces a green output signal G, a blue light receiving portion 63 produces a blue output signal B, and an infrared light receiving portion 64 produces an infrared output signal IR. Four output signals R, G, B, IR from the color solid line sensor 60
Are respectively amplified by the amplifier 31, and the reset noise is removed by the sample hold circuit 32, and then input to the A / D converter 33. Next, the output of the A / D converter 33 is input to the delay circuit 41, and the red, green, and blue signals are each delayed by a desired time. This delay is caused by each of the light receiving units 61, 62, 63, 64.
Position is different with respect to the scanning direction of the scanning image forming unit 14, the output signals R, G, B, I from the color solid line sensor 60 for the image at the same position on the original document.
This is done to correct the position so that R can be obtained at the same time.

Since the operation thereafter is the same as that of the circuit shown in FIG. 3, the description thereof will be omitted. However, in the circuit shown in FIG. 6 as well, the color image forming apparatus 40 has the color images of yellow, magenta, and cyan. It is possible to form a high-quality image with no color tint by reproducing with four colors of black and black, and reproducing black characters and black line drawing with one color of black.

Next, a fourth embodiment of the color solid-state line sensor of the present invention will be described with reference to FIG. In the color solid-state line sensor 70 shown in FIG. 7, the width of the infrared light receiving portion 74 in the long side direction of the line sensor 70 is half the width of the red, green and blue light receiving portions 71, 72, 73, 74, that is, 32 .mu.m is different from the fourth embodiment shown in FIG. Therefore, the light receiving units 71, 72, 73 of the color solid line sensor 70 shown in FIG. 7 color-separate the color image in the original document into three colors of red, green and blue to 400
It can be read at a spi resolution. Further, the infrared light receiving section 74 can read black and white information at a resolution of 800 spi.

[0039]

As described above, according to the present invention, a color image is read after being separated into three colors of red, green and blue, and a monochrome image is read according to the amount of reflected light of infrared rays. Even when a color image and a black-and-white image are mixed therein, it is possible to obtain high-quality image data with no coloring for the black-and-white image.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration example of a color image reading device to which a color solid line sensor of the present invention is applied.

FIG. 2 is a plan view showing a first embodiment of the color solid line sensor of the present invention.

FIG. 3 is a color solid-state line sensor 20 shown in FIG.
It is a block diagram showing a color copying machine using.

FIG. 4 is a plan view showing a second embodiment of the color solid line sensor of the present invention.

FIG. 5 is a plan view showing a third embodiment of the color solid line sensor of the present invention.

FIG. 6 is a color solid line sensor 60 shown in FIG.
It is a block diagram showing a color copying machine using.

FIG. 7 is a plan view showing a fourth embodiment of the color solid line sensor of the present invention.

FIG. 8 is a schematic configuration diagram showing a configuration example of a general color image reading device.

FIG. 9 is a plan view showing a configuration example of a conventional color solid line sensor.

FIG. 10 is a plan view showing a configuration example of another conventional color solid line sensor.

[Explanation of symbols]

10 ... Color image reading device, 11 ... Document holder, 1
2 ... manuscript, 13 ... platen glass, 14 ... scanning imaging unit, 20 ... color solid line sensor, 21 ... red light receiving section, 22 ... green light receiving section, 23 ... blue light receiving section, 30 ... sensor output signal processing Part, 31 ... Amplifier, 32 ... Sample hold circuit, 33 ... A / D converter, 34 ... Resolution conversion circuit, 35 ... Gradation correction circuit, 36 ... Color correction circuit, 37 ... Signal selection circuit, 38 ... Black line determination Circuit: 40 ... Color image forming apparatus, 41 ... Delay circuit, 50 ... Color solid line sensor, 51 ... Red light receiving portion, 52 ... Green light receiving portion, 53 ... Blue light receiving portion, 54 ... Infrared light receiving portion, 60 ... Color solid line sensor, 61 ... Red light receiving part, 62 ... Green light receiving part, 63
... blue light receiving unit, 64 ... infrared light receiving unit, 70 ... color solid line sensor, 71 ... red light receiving unit, 72 ... green light receiving unit, 73 ... blue light receiving unit, 74 ... infrared light receiving unit, 80 ...
Color image reading device, 81 ... Infrared cut filter,
82 ... Color solid line sensor, 82a ... Substrate, 82b
... light receiving element, 83, 84, 85 ... light receiving portion, 86 ... color solid line sensor, 86a ... substrate, 86b ... light receiving element,
86c, 96d, 86e ... Light receiving element array, 87, 88, 8
9 ... Light receiving part

Claims (3)

[Claims] 1. A first line sensor for separating the components of input light into three colors of red, green and blue and outputting each color signal of red, green and blue on a common substrate, and a first line sensor of the input light. A color solid-state line sensor, which is arranged adjacent to a second line sensor that detects an infrared component and outputs an infrared signal. 2. The color solid-state line sensor according to claim 1, wherein the first line sensor is one in which red, green and blue light receiving portions are periodically arranged in a line direction. 3. The color solid-state line sensor according to claim 1, wherein the first line sensor includes red, green and blue light receiving portions extending in the line direction.