JPH10178518A - Image split reader and read method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a reader to read a movement amount by using a line CCD widely spread, to allow the reader to synthesize images with the movement amount and to allow the reader to easily conduct the processing with a digital circuit. SOLUTION: An image area is split into some areas, after an area CCD 6 is moved to read an image split in some times, the obtained images are overlapped each other to synthesize an image. Especially, as information for overlapping the plural images, a light source such as a laser 8 is placed to a frame side that is moved together with the area CCD 6 in order to measure the relative movement of the area CCD 6, a line CCD 7 is provided to a fixed base 9 side in order to sense the light of the light source, the movement amount is calculated based on the measurement result of the line CCD 7 and the images are synthesized based on the movement amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image division reading apparatus and a reading method for reading a high-resolution digital two-dimensional image.

[0002]

2. Description of the Related Art In a conventional method, as a method of synthesizing a digital two-dimensional image, a method using a linear scale, a rotary encoder,
The amount of movement was measured using a sensor such as a slide resistance or a photodiode. Image recognition methods have also been studied as software methods.

FIG. 11 shows a conventional configuration example. 61 is a base plate, 62 is a sub-scanning direction moving guide, 63 is a main scanning direction moving base, 64 is a main scanning direction moving guide, 65
Is an area CCD mounting base, 66 is an area CCD, 6
7 is a linear sensor using an optical scale, 68, 6
8 'is a laser, and 69 is a photo sensor.

The image division reading apparatus divides an image while moving the area CCD 66 and inputs the image.
In order to measure the amount of movement of the area CCD 66, measurement is performed using the 67 linear sensors. Although the moving method is not shown in this figure, means such as a feed screw, a linear motor, and a feed belt are used. The linear sensor 67 is used to measure two directions, the main scanning direction and the sub-scanning direction.
Use one.

FIG. 12 shows a linear sensor. On the linear sensor 71, opaque graduations 72 are drawn at regular intervals. The number of straight lines passed by the photodiode is measured by the number of times that the light from the laser diode is intercepted during the interval, and the moving distance is measured. Is what you do.
In this case, since an optical linear sensor is used, it is impossible to perform measurement with an accuracy greater than the width of a straight line.

[0006]

SUMMARY OF THE INVENTION In addition to the above,
Another problem with the method of performing image synthesis using software is that the processing time and the amount of processing calculations are large, and that a large amount of processing time and a high-speed processing circuit or a large amount of processing circuits are required. is there.

[0007] Specifically, in the method using a linear scale, the price of the linear scale is expensive and adjustment is difficult. Also, the light source used for the measurement needs to be narrowed down to the width of the measurement accuracy or a narrow slit is required. In the case of a rotary encoder, the moving system requires rotation or a mechanism for converting to rotation.
Accuracy is a problem in the slide resistance, and an accurate A / D converter is required for accurate measurement.
In photosensors, considerable cost and technology were required to mount such components.

[0008] In view of the above, according to the present invention, a moving amount is read by a line CCD which is widely used, an image can be synthesized based on the moving amount, and an image can be easily processed by a digital circuit. It is an object to provide a reading device.

When the moving distance is obtained, if the length of the side of the pixel of the area CCD is different from the length of one pixel of the line CCD, an arithmetic circuit for conversion and an arithmetic time are required. Area CC on the moving frame side
Since the length of one pixel side of D is equal to the length of the corresponding fixed base-side line CCD, an object of the present invention is to provide a dedicated circuit for conversion or an image reading apparatus capable of eliminating an arithmetic processing time. .

In addition, since the number of bars passing through the conventional linear sensor was counted, it was impossible to measure the distance beyond the bar interval. However, the present invention combines the following one pixel with the two pixels on the boundary. It is an object of the present invention to provide an image reading apparatus that can superimpose images according to the ratio of incident illuminances and that can synthesize images more accurately.

Further, in the case of obtaining the moving amount of the linear CCD, the digital operation must be performed similarly to the case of the area CCD. Therefore, the moving amount is obtained by using a digital circuit through a dedicated A / D converter. However, according to the present invention, the area CCD and the line CCD
It is an object of the present invention to provide an image reading apparatus which can share a part of the digital processing circuit by sharing the A / D converter described above, and as a result, the number of parts can be reduced.

[0012]

According to the first aspect of the present invention, an image area is divided into several parts, an area CCD is moved over the area, and an image is read several times. In an image division reading apparatus that superimposes the obtained images and synthesizes one image, it is necessary to measure the relative movement amount of the area CCD as information for superimposing a plurality of images. For this purpose, a light source such as a laser is installed on the frame side that moves together with the area CCD, and a line CCD is installed on the fixed base side to detect the light, and the amount of movement is calculated based on the measurement results of the line CCD. An image division reading apparatus characterized in that image synthesis is performed using values.

According to the second aspect, the length of one pixel side of the area CCD on the moving frame side in the first aspect is as follows.
An image division reading apparatus is used, which is equal to the length of the side of one pixel of the corresponding line CCD on the fixed base side.

According to a third aspect of the present invention, there is provided an image division reading apparatus according to the second aspect, wherein the following combination of one pixel is superimposed on the basis of a ratio of incident illuminance of two pixels at a boundary.

According to the fourth aspect, in the case of the first aspect, the linear CCD is input to the input of the A / D converter used in the area CCD, and a digital circuit for processing is shared.

According to the fifth aspect, the image area is divided, the area CCD is moved over the area, the image is read several times, and the obtained images are superimposed on one another.
An image division reading method for synthesizing a plurality of images, wherein a laser or the like provided on a frame side that moves with the area CCD to measure a relative movement amount of the area CCD as information for superimposing the plurality of images. Irradiating light with the light source, measuring the light, calculating a moving amount based on the measurement result, and synthesizing the image based on the calculated value.

According to the first aspect, it is possible to calculate an amount of movement of the area CCD based on the measurement result of the line CCD, and to synthesize an image divided and captured according to the calculated value.

According to the second aspect, since the length of the side of one pixel of the area CCD on the moving frame side in the first aspect is equal to the length of the corresponding line CCD on the fixed base side,
A dedicated circuit for conversion or an arithmetic processing time can be eliminated.

According to the third aspect, in the apparatus of the second aspect, the following composition of one pixel can be superimposed on the basis of a ratio of incident illuminance of two pixels at a boundary, and more accurate image composition is possible. Becomes

According to the fourth aspect, the A / D converter of the area CCD and the line CCD is shared by the second aspect, so that a part of the subsequent digital processing circuit can be shared, and as a result, the number of parts can be reduced. Reduction is possible.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;
FIG. 1 is a configuration diagram illustrating an apparatus configuration according to an embodiment of the present invention.

(First Embodiment) FIG. 1 shows an embodiment of the present invention. FIG. 1A shows an apparatus configuration.
(B) AA is a sectional view.

In FIG. 1, reference numeral 1 denotes a base plate, on which a sub-scanning direction moving guide 2 and a fixed base 9 for a line CCD are mounted. The main scanning direction moving base 3 is mounted on the base 2. 4 is a main scanning direction moving guide,
5 is the area CCD mounting base on it.

Although the moving methods 3 and 5 are not shown in this figure, means such as a feed screw, a linear motor, and a feed belt are used. 6 is an area CCD, 7 is a linear CCD
It is. Reference numerals 8 and 8 'denote lasers.
And 8, 8 'move similarly. The beam 10 is radiated by the laser 8 'onto the line CCD 7 and in this manner,
Of the area CCD can be measured by the seven linear CCDs.

FIG. 2 shows a block diagram of the subsequent processing circuit. Control signals for 12 line CCDs are generated by 11 control signal circuits. In the line CCD 12, the intensity of the laser light is converted into a voltage and input to the signal amplification circuit 13. At 13, the obtained signal is amplified to a voltage that can be measured by the A / D converter 14. The address counter 15 counts signals output from the control signal circuit 11 to generate addresses of the memory 16.

The memory 16 stores the address generated by the address counter 15 and the data of the A / D converter 14. The arithmetic circuit 17 detects the current position by calculating from the data in the memory 16, and calculates the number of pixels to be moved based on the pixels of the line CCD from the positions before and after the movement.
After that, the calculation based on the pixels of the area CCD is performed.

Circuits other than 12 line CCDs, 13 signal amplifier circuits, and 14 A / D converters can be implemented as digital circuits. The line CCD in this patent
If the density is increased in the future, it can be realized by replacing it with another photodetector such as a photodiode, a cadmium cell, or a solar cell.

FIG. 3 shows how images are superimposed based on the measured number of moving pixels. (1) in FIG.
This figure shows a state in which a document is divided into 12 times and taken in. Among them, the upper left and right originals are shown in FIGS. 3 (2) and 3 (3), respectively.

Although basically moving in one direction,
Movement also occurs in another direction due to the accuracy of the guide,
The number of moving pixels in the horizontal direction is obtained, and the number of moving pixels in the horizontal direction is represented by X,
The number of pixels moved in the vertical direction is represented by Y. FIG. 3 (4) shows a state in which an image divided and taken in based on the number of moving pixels is overlapped by obtaining a length to be overlapped by the number of moving pixels.

FIGS. 4 and 5 show how to determine the number of moving pixels.
FIG. 4 is a diagram showing the number of moving pixels when the area CCD moves in the main scanning direction. This is a case where the area CCD which was initially at the 21st position has moved to the 22nd position, and the number of moving pixels corresponds to the main scanning direction moving distance 23 and the sub-scanning direction moving distance 24. The same applies to FIG.

(Embodiment 2) In the case where the number of pixels on the area CCD to be superimposed is determined by the pixels of the line CCD moved in the first embodiment, the moving distance differs from the pixel size in the first embodiment. Conversion work was required.

For example, when the pitch of the linear scale that can be measured is 10 micron, the pixel of the area CCD is 9.1 micron, and the measurement moving distance is a * 10 micron, the calculation is b = a * 10/9. .1, and multiplication is required even if (10 / 9.1) is obtained from the beginning.

FIG. 6 shows a line CCD 32 and an area CCD.
FIG. 11 shows a diagram in which superposition is performed when the size of 31 pixels (35 after movement) is equal. In the present invention, since the size of the area CCDs 33 and 36 on which the size of the measurement pixels of the linear CCDs 34 and 37 are to be overlapped is equal to the size of the line CCD to be measured, this calculation becomes unnecessary.
A calculation time or a dedicated circuit for that is not required.

(Embodiment 3) In the apparatus according to embodiment 2, the following combination of one pixel is obtained by the ratio of the incident illuminance of the two pixels at the boundary, and is superimposed based on the information.
FIG. 7 shows a means based on illuminance for obtaining the moving distance of one pixel or less.

Light emitted from the laser is scattered due to interference or the like and is incident on some pixels of the line CCD. Therefore, two pixel points close to a certain reference illuminance are searched for, and the position of the target illuminance is obtained from the illuminance of the pixel point, thereby obtaining a moving distance smaller than one pixel.

The accuracy depends on the time variation of the laser beam and the accuracy of the A / D converter. Line CCD
FIG. 8 is a diagram showing how the distance is obtained after the signal is converted into a digital signal through an A / D converter. Since the illuminance is digitized and the measurement position is also for each pixel of the line CCD, the illuminance is in a staircase state as shown in the figure. The two points (A, B) closest to the reference illuminance are taken, and the position of the reference illuminance is interpolated to obtain the laser position.

FIG. 9 is a flow chart of the method for obtaining the value.
Shown in Steps (hereinafter simply referred to as “S”) S1 to S
The pixel boundary of the pixel illuminance exceeding the reference illuminance S up to 5, the illuminance thereof, and the illuminance immediately before the boundary are obtained. Then, a calculation is performed based on the data to determine a pixel position on the line CCD.

As an example, the reference illuminance S = 128, C = 100
P =＝ 100 * (128-32) + (100-1) * when D = 192 and the previous illuminance is D = 64 at the location
(160−128)｝ / (160−32) = 99.75, and the pixel position is calculated as 99.75.

(Fourth Embodiment) In the first embodiment, when a digital circuit for taking in an image for an area CCD and a digital circuit for a line CCD are compared, many parts can be used in common.

FIG. 13 shows a conventional example. In the related art, there are overlapping components that do not need to operate at the same time, such as a signal amplifier circuit, an A / D converter, a control signal generation circuit, and a memory for a CCD.

FIG. 10 is a circuit block diagram of the present invention. Control signal circuit 41, line CCD 42, signal amplification circuit 43, selectors 51 and 51 ', A / D converter 5
4, an address counter 55, a control signal circuit 60, an area CCD 58, a signal amplifying circuit 59, a memory 56, and an arithmetic circuit 57.

The outputs of the line CCD 42 and the area CCD 58 are switched when necessary by 11 selectors (analog switches) 51 ', and a portion for processing digital signals after the A / D converter 54 in FIG. 10 is commonly used. By doing so, the number of common blocks for post-processing increases, and the number of circuits can be reduced.

In addition, the present invention is not limited to the embodiment described above and shown in the drawings, and it is needless to say that the present invention can be appropriately modified and implemented without departing from the scope of the invention.

[0044]

According to the image dividing and reading apparatus of the present invention, a moving amount can be read by a widely used line CCD, and an image can be synthesized based on the moving amount, and processing can be easily performed by a digital circuit. It is possible to do.

According to the image division reading apparatus of the second aspect,
The number of pixels for superimposing images can be obtained without performing calculation by a circuit or a program for converting the amount of movement of the position.

According to the image division reading apparatus of the third aspect,
The accuracy of superimposition of images can be improved without increasing the number of lines of the line CCD or reducing the spot diameter of a light source such as a laser.

According to the image division reading device of the fourth aspect,
The movement amount can be measured and images can be superimposed by adding only a minimum necessary digital circuit.

[Brief description of the drawings]

FIG. 1 is a diagram showing an apparatus configuration according to an embodiment of the present invention. (A) is an apparatus configuration, and (B) is an AA sectional view.

FIG. 2 is a block diagram of a circuit for calculating an inventive movement distance according to the present invention.

FIG. 3 is a diagram showing an actual operation of the image division reading apparatus of the present invention.

FIG. 4 is a diagram illustrating a state in which a line CCD moves in a main scanning direction.

FIG. 5 is a diagram illustrating a state in which a line CCD moves in a sub-scanning direction.

FIG. 6 is a diagram showing a relationship between pixel length and movement of an area CCD and a line CCD.

FIG. 7 is a graph showing a means for detecting a position on the surface of the line CCD from the illuminance by the laser beam and the reference illuminance.

FIG. 8 is a graph showing means for detecting a position more precisely than a line CCD from an illuminance output signal of the line CCD by a laser beam.

FIG. 9 is a flowchart for detecting the position of an area CCD.

FIG. 10 is a circuit block diagram of the present invention.

FIG. 11 is a configuration diagram illustrating a conventional example.

FIG. 12 is a diagram of conventional line encoding.

FIG. 13 is a conventional circuit block diagram.

[Explanation of symbols]

 Reference Signs List 1 base plate 2 sub-scanning direction base 3 main scanning direction base 4 main scanning direction moving guide 5 area CCD mounting base 6 area CCD 7 line CCD 8 laser 9 line CCD fixed base 10 light beam

Claims (5)

[Claims] An image in which an image area is divided, an area CCD is moved over the area, images are read several times, and the obtained images are superimposed to synthesize one image. In the divided reading device, as information for superimposing the plurality of images, an area C
A light source such as a laser provided on a frame side that moves together with an area CCD to measure a relative movement amount of a CD; and a line CCD on a fixed base side to sense light of the light source. Calculate the movement amount based on the measurement result,
An image division reading apparatus that performs image synthesis based on the value. 2. The moving area CCD according to claim 1.
The length of one pixel is equal to the length of the vertical line CCD on the fixed base side, the width of one pixel of the area CCD is equal to the length of the horizontal line CCD on the fixed base side, or both conditions. An image division reading device characterized by having. 3. The image division reading apparatus according to claim 2, wherein the following composition of one pixel is superimposed on the basis of a ratio of incident illuminance of two pixels at a boundary. 4. An image division reading apparatus according to claim 1, wherein an output signal of the line CCD is input to an A / D converter for an area CCD and post-processing is performed. 5. An image in which an image area is divided, an area CCD is moved over the area, an image is read several times, and the obtained images are superimposed to synthesize a single image. A divided reading method, wherein information for superimposing the plurality of images includes an area C
Irradiating light with a light source such as a laser provided on the frame side that moves with the area CCD to measure the relative movement amount of the CD; measuring the light; and calculating the movement amount based on the measurement result. An image division reading method which calculates and performs image composition based on the calculated value.