JPS58130360A - Image reading device - Google Patents

Abstract

PURPOSE:To obtain an exact image of a solid object obtainable by moving along its surface, by correcting the distance data of image data obtained by a light receiver to an actual distance data, when the distance between the light receiver and the object changes. CONSTITUTION:A lens 6 for forming an image on a light receiver 5 is supported vertically movably with a drive motor 8 and a gear 9, and the distance between the receiver 5 and a book 3 is measured with optical range-finders 13, 14. When the receiver moves left, the distance between this and the book 3 is detectd with the range-finders 13, 14, the lens 6 is moved in accordance with the detected distance, and an image is formed on the receiver 5. Since the actual distance DELTAz along the solid surface of the book 3 is approximately the square root of the sum of DELTAx squared and DELTAy squared, where DELTAx and DELTAy are each movement distance, this correction is calculated with a prescribed correction circuit to correct image data. As a result, an image obtainable by moving along the surface of the solid object to be obtained and exact reading to be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image reading device, and more particularly to an image reading device that detects the distance between a light receiver and an object and controls the distance between the light receiver or an optical device such as a lens and the object. .

Conventionally, devices of this type, such as copying machines and optical character reading devices, have been designed to handle characters written on flat surfaces or images on one surface, so they cannot be used with devices such as thick books, as shown in Figure 1. When reading a data sheet, only the images or characters in the portions that were in close contact with the document table (between A and B, between CD and C) could be read.

This is because the readable position of the reading device is fixed on the paper table, and no image is formed on the light receiver.

The present invention has been made in view of the above points, and includes a distance detector that measures the distance between a light receiver that optically reads an image and a target object that reads image data, and the distance from the light receiver to the target object is measured. When convenient, by correcting the interval of image data obtained by the photoreceptor to the actual interval, even if the object is three-dimensional, image data can be obtained as if it were obtained along the surface of the three-dimensional object. An object of the present invention is to provide an image reading device that can perform the following functions.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a structural diagram of an image reading device that is an embodiment of the present invention. 3 is a thick book to be read, which is placed on the manuscript table 4. 05 is a photoreceptor, and the image is formed on the photoreceptor and the signals necessary for storing or transmitting the nine words, such as electricity, etc.
It converts it into an optical signal. 6 is a lens, and the light receiver 5
It is fixed to the lens stand 7 to form an image of the upper IIc. Reference numeral 8 is a lens stand drive motor, and when this is rotated, a gear 9 engages with K to move the y-z stand up and down.01G is a lens stand drive motor 8;
At the stand that supports the light receiver 5, the support stand drive motor II is connected to To.
K, it moves in the scanning direction via the timer belt 12.

13.14 is an optical distance needle that measures the distance between the lens support 7 and the reading point E. Specifically, the optical distance needle located on the lens support 7 is connected to the light emitter 13 and the receiver ff1a.
14 f, so that the distances between the center point of the lens and the F cover are equal, and the angle between the emitter 13 and the mounting base is always equal to the angle between the light receiver 14 and the mounting base. The optical distance needle scans in the - direction as shown in the enlarged view of the 21I (b) optical distance needle. Light with strong directionality is emitted from the Tsuya light emitter 13, and when the light from the point EK emission @13 on the object hits, the reflected light is received by the receiver, and the amount of light received at this time is is the maximum. Therefore, by knowing the angle d formed between the O mount and the light emitter 13 or the light receiver, the distance between the object and the mount can be calculated from the distance from the light emitter 13 or the light receiver 14 to the center point F of the lens O. 1, then EF m atam can be obtained.
1 is a distance detection circuit.

This distance detection circuit 31 includes an angle detection circuit 32 that detects an angle as shown in FIG. It consists of a distance calculation circuit 33 that calculates the distance to a point where data exists by performing an a tan calculation. 34 is the distance (9) obtained from the distance calculation circuit 33, where f is the focal length of the lens 6 shown in FIG. This is a focus position calculation circuit that calculates an appropriate lens position (denoted as C) for forming an image on the light receiver 5 from ÷--+-t. This focus position calculation circuit 34 is
O35 is a circuit that receives the distance value from the distance calculation circuit 33' and calculates the lens position C by calculating C=seedling.

This is a storage circuit for temporarily storing the lens position data calculated and obtained by the focus position calculation circuit 34, and when such lens position data is sent to this storage circuit 35, the previous lens position data will be described later. 036, which is sent to the comparison circuit, is a comparison circuit that compares the focus position data obtained by the focus position calculation circuit 34 at the current lens position with the focus position data at the previous lens position from the storage circuit 35. It is something to do. 37 is a comparison circuit 36
0, which is a lens drive circuit that moves the position of the lens 6 by the output from the comparator 35. In other words, when the focus position data from the focus position calculation circuit 34 and the focus position data from the storage circuit 35 are equal, the output from the comparator 35 is 0 and the lens 6 does not move, but if different, the comparator 36
The lens stand drive motor shown in FIG. 2(a) is driven according to the output from the lens 6 to move the lens 6 up and down. The state of the memory circuit 35 when the power is turned on is shown in FIG. 2(a).
As shown in FIG. 2, the appropriate lens position at which the image should be formed on the light receiver 5 when there is image data to be read on the document table 4 is stored.

Next, the operation of the nine control circuits constructed above will be explained using the movement of the lens shown in FIG. 2(a) as an example. When the image is formed at point G, the center of the lens 6 is F, and the focal length of the lens 6 is f, then the lens focus position data FG is stored in the memory circuit 35. has been done. Next, in order to move the lens support 10 in parallel and connect the point on the lens 3 to the point on the light receiver 5, first, the angle detection circuit 32 connects the light emitter 13 or the light receiver 14 to the mounting base. The angle α' formed by the angle α' is detected and sent to the distance calculation circuit 33. The distance calculation circuit 33 uses the angle data sent from the angle detection circuit 32 to calculate the distance from point 20 to point H, and sends the distance data to the focus position calculation circuit 34. When the center point of the lens 6 is at two points, the focus position calculation circuit 34 calculates the distance from the two points to the point where the image data at the H point of the book 4 is formed, and as a result, the comparator 36 At the same time,
It is also sent to the storage circuit 35. When the distance data from the focus position calculation circuit 34 is stored in the storage circuit 35, the previous focus position data FG is outputted to the comparator 36. Therefore, the comparator 36 compares these two data, and the difference between these data is sent to the lens drive circuit 37. Therefore, the lens drive circuit 37 drives the lens drive motor 8 based on the output from the comparison circuit 36, and the lens 6 is moved. As a result, as the lens 6 moves, the distance from point H on the book 4 to the center of the lens 6, a, changes, and the position of the imaged point also changes, so the above-mentioned control is repeated multiple times. The lens 6 finally stops when it has lowered by (FG-JK), and the height of point H on the book 4 is imaged upward on the light receiver.

In the manner described above, image data at points that are not on the document table can be obtained.

FIG. 4 explains how to process the obtained nine-stroke data. In FIG. 0, 41 is a three-dimensional object, and it is assumed that there are points ~, N, ~N on its surface. Reference numeral 42 denotes a document table that allows light to pass through. Paddle the image to each point on the surface,...
, NJ. The image data projected onto the same plane as the document table may be Nt, -.

There is no match except between N1. The distance in the y direction between each point is Δ
y3. ..., Δy4, the distance between each point on the surface of a three-dimensional object can be approximated as Δ2×aπi〒×yi)''. When the position between each point is approximated from this formula, the obtained image is Data pigeon, for.

The pigeon is u; I, -, H:'. This is almost the same as the image data obtained along the three-dimensional object 41. Therefore, by storing or transferring the image data of mind', . . . , N:', it becomes possible to obtain image data along the surface of the three-dimensional object. There is no need to perform the above processing on images on the surface that is in contact with the normal document glass or on the surface that is parallel to the document glass, so it is only necessary when there is a change in the distance between the light receiving point and the object. The above processing will be performed.

Next, FIG. 5 shows a block diagram showing the configuration of an image data processing circuit for obtaining image data as shown in FIG. 4. In the figure, 5 is a light receiver as shown in Figure 2(a).
This light receiver 5 obtains image data of points N·, N, to Nl on a three-dimensional object 41-E as shown in FIG. 51 is N, i N, ~ obtained from the photoreceiver d at intervals of ΔX.
In order to correct the image data of the point N to the image data with the actual spacing on the three-dimensional object 41, a correction circuit outputs image data whose spacing is corrected by an output from an arithmetic circuit, which will be described later. . 52 is based on the data of the distance circuit 33 shown in FIG.
Δzl = (x
This is an arithmetic circuit that calculates the distance between actual image data by calculating x)"-) (xyi)". Further, the above-mentioned arithmetic circuit 52 calculates the previously calculated interval data Δy in the y direction.
It has a storage section 52' that stores 1.

The operation of the image data processing circuit configured as described above will be explained below.

First, it is assumed that the interval data of Δyl shown in FIG. Next, nine stroke height data Nj is inputted from the light receiver 5 to the correction circuit 51, taking into account the interval data ΔX from the image data group. At the same time, distance data from the center point of the lens to point N3 on the three-dimensional object 41 is output from the distance calculation circuit 33 in FIG. 3 to the calculation circuit 52. Therefore, the calculation circuit 52 calculates the distance data (Δy, +Δy,) in the y direction based on the distance data from the distance calculation circuit 33.

By subtracting the interval data Δ3't stored in the storage unit 52', the interval data Δy in the y direction from N to N,i on the three-dimensional object 41 is obtained. Furthermore, in the arithmetic circuit 52, the interval data Δ
y, is stored in the storage unit 52' and Δz, -β+(Δy,)1
Then, the actual distance from the lump on the three-dimensional object 41 to N is calculated. This actual interval data Δ2. is output from the arithmetic circuit 52 to the correction circuit 51. Correction circuit 51
Then, the image data Nj including the interval data ΔX obtained from the light receiver 5 is corrected by the image data Nk including the interval data of the actual interval outputted from the arithmetic circuit 52, and is output to the storage means or the transfer means. The same applies when the above-mentioned patterns N: and N: are obtained by the photoreceiver 5.

In the above explanation, the effect was achieved by moving the position of the lens, but the same effect can also be obtained by moving the position of the receiver. , there is no need to stick to this method; other methods may be used.

As explained above, by providing means for measuring the distance between the light receiver and the object to be read, and controlling the position of the light receiver or condenser, image or character data on the surface of an object with a three-dimensional structure can be read. It is possible to read accurately,
Furthermore, even when the distance between one light receiving point and the object changed, by correcting the image data, it was possible to obtain image data obtained by scanning along the surface of the three-dimensional object.

[Brief explanation of drawings]

Fig. 1 is a state diagram when a thick book is folded on a document table, Fig. 2 (a) is a structural diagram of an image reading device which is an embodiment of the present invention, and Fig. 2 (a) is an optical Enlarged view of rangefinder, 3rd
The figure is a block diagram of a control circuit that controls the nine-stroke image reading device shown in FIG. 2, FIG. 4 is a diagram for explaining how to process image data, and FIG. 5 shows the image shown in FIG. 4. This is a block diagram of an image data processing circuit with 4 as the data processing method, 5 is a light receiver, 51 is a correction circuit, 52 is an arithmetic circuit, 5
2f is a storage section. Detonjin Canon Co., Ltd.

Claims (1)

[Claims] In an image reading device that includes an optical receiver and a condenser for forming an image on the receiver and optically reads image data of an object, a distance detection device that measures the distance between the receiver and the object and correction means for correcting interval data between image data obtained by the light receiver to actual interval data when the distance changes by the distance detection means. Device.