JPH06105940B2 - Image reader - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image reading apparatus that obtains a photoelectric conversion signal for a character, a graphic, or the like written on a document by a manual feeding operation.

[Conventional technology]

FIG. 4 shows a reading method by a conventional image reading apparatus by manual feeding operation. In this figure, 1 is a manuscript, 2 is characters, figures, etc. written on the manuscript 1 (hereinafter simply referred to as characters)
Is. Reference numeral 3 is a lens optical system, which uses a spherical surface, a lens, and a focusing fiber array. Reference numeral 4 is a light source for illuminating an original, and a solid-state light source such as a tungsten lamp or an LED is used. Reference numerals 5-1 and 5-2 are first and second sensors (hereinafter, simply referred to as sensors) each including a one-dimensional image sensor,
Thin film photoelectric conversion element such as CdS, CdSe or Si such as CCD, MOS
A device is used.

The reading method is to move the sensor 5-
Reference numerals 1 and 5-2 read a character 2 (for example, "A") written on a document 1 through a lens optical system 3. The operation of the reading method at this time is shown in FIG.
It is (b). Sensors 5-1 and 5-2 are arranged at a distance D,
When scanning is performed in the direction of arrow 6, FIG.
-1 shows the moving state when "black" is detected, and FIG. 5 (b) shows the moving state when "black" is detected at the sensor 5-2.

When the moving state of FIG. 5 (a) is changed to the moving state of FIG. 5 (b), the basic scanning number N ₀ is represented by N ₀ = n × D, where n is the linear density in the moving direction. . If the moving speed corresponding to this is V _0, and the number of scans during the actual manual feeding operation is N, the moving speed V at that time is It is represented by. Thus, if the moving speed is normalized by the ratio N ₀ / N of the basic number of scans N ₀ and the actual number of scans N, a character equal to the character obtained when moving at the basic manual feed speed can be obtained.

Further, even after the state of FIG. 5B, the character 2 can be read by performing the same processing assuming that the moving speed V is constant.

[Problems to be solved by the invention]

In the conventional image reading apparatus as described above, the speed is detected only when the white pixel changes to the black pixel on the sensors 5-1 and 5-2, so that a large character / graphic or speed change is detected. However, there are drawbacks in that the speed cannot be detected sufficiently when the value is large, and the image is distorted due to shaking or fluctuation due to manual operation.

Further, there is a drawback that two expensive one-dimensional image sensors are required for speed control.

The present invention has been made to solve these drawbacks, and an object thereof is to provide an image reading apparatus capable of always detecting a correct speed.

[Means for solving problems]

A one-dimensional image sensor for reading an image reading document according to the present invention, a movement amount detector provided in at least one of the longitudinal direction of the one-dimensional image sensor for detecting the movement amount in the X direction and the Y direction, and a manual feed operation With the movement of the one-dimensional image sensor, the movement detector detects the movement amount in the X and Y directions at the same time, and calculates the image distortion caused by the speed change, camera shake, tilt, and the like, and the calculation means. And a correction circuit that corrects the image read by the one-dimensional image sensor using the image distortion obtained in (1).

[Action]

In the present invention, when the one-dimensional image sensor is moved, the movement amount detector detects the movement amounts in the X direction and the Y direction. Therefore, the velocity change, the inclination, etc. are detected from the values, and the image is detected based on this. Make a correction.

〔Example〕

FIG. 1 shows an embodiment of the present invention. 7-1
Is a ball-shaped moving body such as a pointing device, and is movable in any direction on the document surface. 7X is a movement amount detector in the X direction, and 7Y is a movement amount detector in the Y direction. However, the X direction represents the direction in which the sensor moves left and right, and the Y direction represents the direction in which the sensor moves up and down. A one-dimensional image sensor 8 is provided with movement amount detectors 7X and 7Y integrally. Reference numeral 9 denotes a locus that is moved in parallel to the X direction as shown by an arrow, 10 is a locus that is slanted, and θ ₀ is a tilt when the slant is moved. Reference numeral 11 is an X-direction movement amount calculation circuit, 12 is a Y-direction movement amount calculation circuit, and 13 is an arithmetic circuit that calculates an inclination based on the movement amounts in the X and Y directions. Reference numeral 14 is a distortion correction transmission terminal, and 15 is a correction circuit.

The initial position is indicated by the state (i), and the state (ii) indicates the state when the locus 9 is moved in parallel with the arrow direction indicated by the trajectory 9. The state (iii) shows a state when moving diagonally in the direction of the arrow shown by the locus 10.

Next, these operations will be described.

First, when moving from state (i) to state (ii),
Since the movement amount detector 7Y in the Y direction has a value of 0 because it is moving in parallel, only the movement amount detector 7X in the X direction operates.

The number of lines of the read image required for the movement amount x at this time is read by the one-dimensional image sensor 8, and the distortion correction amount necessary for correcting distortion such as speed and deviation is output from the distortion correction sending terminal 14. This enters the correction circuit 15 and the necessary correction is applied to the read signal from the one-dimensional image sensor 8 to obtain a corrected image.

Actually, the movement amount detectors 7X and 7Y use variable resistors or the like, and are configured so that the resistance value changes in association with the movement of the moving body 7-1. The movement amount calculation circuit 11 and the Y-direction movement amount calculation circuit 12 convert the number of pulses according to the movement amount. The movement amounts x and y are obtained by counting the number of pulses.

Next, when the state (i) is moved diagonally to the state (iii), both movement amount detectors 7X and 7Y in the X and Y directions are activated to obtain the movement amounts x and y, and the arithmetic circuit 13 is used. Inclination θ ₀ = t
Find an ^-1 y / x. The correction method shifts the image read by the one-dimensional image sensor 8 according to the inclination θ ₀ , and an image without distortion is obtained. As mentioned above, for the speed change, X
Correct by the amount of movement in the direction.

FIG. 2 shows another embodiment of the present invention. This shows the state of shaking that occurs when a manual feed operation is performed. here,
Reference numerals 16 and 16 'indicate the moving directions, and the inclinations at that time are θ ₁ and θ ₂ , respectively. The moving state moves from the state (i) to the state (iv), and further to the state (v). In the initial state, the X and Y movement amount detectors 7X and 7Y have a value of 0.
As a result, when the state is moved to the state (iv), the desired inclination θ ₁
Becomes a negative value and the image read by the one-dimensional image sensor 8 is reverse-shifted to obtain an image without distortion. Moving from the state (iv) to the state (v) is the same as moving diagonally as shown in FIG. 1, and the image is shifted and corrected in accordance with the inclination θ ₂ . Therefore, the shake due to manual operation,
It is possible to obtain and correct the inclination and movement amount of the read image when scanning in an arc shape.

FIG. 3 shows still another embodiment of the present invention. Figure 1,
The embodiment shown in FIG. 2 has been described with respect to the case where the manual feeding operation moves on the original surface in a direction parallel to the one-dimensional image sensor 8. FIG. 3 shows a one-dimensional image sensor 8 provided with moving bodies at both ends in the longitudinal direction. As a result, it is possible to correct the read image when the camera is tilted from the beginning and when the manual operation is about to end. This will be described below.

3, the same parts as those in FIG. 1 are designated by the same reference numerals. 7-2 is the same moving body as the moving body 7-1, and 7'X and 7'Y are movement amount detectors in the X and Y directions. The first time when moving from (i) to (ii)
The same operation is performed as shown in the figure. When moving from the moving state (ii) to the moving state (vi), the moving body 7-1 is rotated in the direction of the arrow 17 with an inclination of θ ₃ .

At this time, the moving body 7-2 is detected by the moving amount x _{1 in} the X direction and the moving amount y ₁ in the Y direction. The slope α at this time is represented by α = tan ⁻¹ y ₁ / x ₁ . Therefore, by detecting the inclination α, the actual inclination θ ₃ can be obtained by θ ₃ = 2α. Accordingly, if the image read by the one-dimensional image sensor 8 is bit-shifted by the inclination θ ₃ , the distorted read image can be corrected. Although not shown, the moving body 7-
It is possible to obtain and correct the deviation from the difference in the positional relationship between 1 and 7-2.

〔The invention's effect〕

As described above, according to the present invention, since the movement amount detectors in the X and Y directions are provided in the one-dimensional image sensor, the distortion of the read image such as the speed change and the shaking due to the manual feeding operation is moved in the X and Y directions. Distortion correction can be performed from the movement amount obtained by the detector. In addition, by mounting the displacement detectors in the X and Y directions on both sides in the length direction of the one-dimensional image sensor,
There is an advantage that it is possible to correct a tilted operation during a manual feed operation, a blur near the end of a manual operation, and the like, and a read image can be obtained as an image close to the original image without distortion.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of one embodiment of the present invention and a block diagram of a circuit, FIG. 2 is a schematic diagram showing another embodiment of the present invention, and FIG. 3 is a further embodiment of the present invention. FIG. 4 is an explanatory diagram showing a reading method by a conventional image reading apparatus, and FIGS. 5 (a) and 5 (b) are diagrams showing the relationship between characters and sensors in the conventional example of FIG. is there. In the figure, 7-1 and 7-2 are moving bodies, 7X and 7Y are movement amount detectors, and 8
Is a one-dimensional image sensor, and 9 and 10 are loci.

Claims (2)

[Claims] 1. A character written on a manuscript by a manual feed operation.
In an image reading device for reading information such as a figure, a one-dimensional image sensor for reading a document and a movement amount detector provided in at least one of the longitudinal directions of the one-dimensional image sensor for detecting the movement amount in the X and Y directions. And a moving means for moving the one-dimensional image sensor at the same time as a manual feeding operation, at the same time detecting a moving amount in the X and Y directions by a moving detector, and calculating an image distortion caused by a speed change, camera shake, inclination, etc. An image reading apparatus comprising: a correction circuit that corrects an image read by the one-dimensional image sensor by using the image distortion obtained by the arithmetic means. 2. The image reading apparatus according to claim 1, wherein movement amount detectors for detecting the X direction and the Y direction are provided at both ends in the longitudinal direction of the one-dimensional image sensor.