JPH0521272B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention reads an arbitrary pattern on a document by manually moving a line image sensor that performs main scanning in the sub-scanning direction on the document. The present invention relates to a pattern reading device.

[Prior Art] In this type of pattern reading device, the sub-scanning is performed by a manual movement operation, so the scanning speed in the same direction is likely to fluctuate. Therefore,
If the main scanning of the line image sensor is performed at a constant time period, the interval between the reading lines on the document will vary, causing uneven resolution and making it impossible to obtain a good reproduced image. Therefore, a mechanism is provided in which main scanning of the line image sensor is performed every time the line image sensor moves a certain distance in the sub-scanning direction. Usually, a rotary encoder is attached to one of the rollers for moving the device in order to obtain the timing when the device has moved a certain distance.
The moving distance is detected from the rotation amount or rotation speed of the roller.

In conventional devices of this type, only one moving distance detecting means or moving speed detecting means, such as the above-mentioned rotary encoder, was provided at one location of the device.

[Problems to be Solved by the Invention] By the way, if the device shakes due to the operator's camera shake during a moving operation, the line image sensor may be tilted diagonally during main scanning, and in that case, the interval between the reading lines may be reduced. They shift and are no longer parallel. However, in conventional devices, a moving distance detecting means such as a rotary encoder or a moving speed detecting means is one part of the device.
Since there is only one sensor installed at each location, it is not possible to detect when the reading line is tilted, and the output signal of the line image sensor is output as is, assuming that the reading line always moves in parallel at equal intervals. It was imported as image information corresponding to pattern information. As a result, there was a problem that distortion occurred in the reproduced image.

The present invention has been made in view of such problems, and it is an object of the present invention to provide a manually operated pattern reading device that corrects blurring of a line image sensor due to camera shake, etc., and obtains a reproduced image without distortion. purpose.

[Means for Solving the Problems] In order to achieve the above object, the pattern reading device of the present invention is a pattern reading device that reads an arbitrary pattern on a document and converts the pattern information into electrical image information. , a light emitting unit that irradiates light to the reading line on the document;
A large number of photoelectric conversion elements that receive reflected light from a reading line on the document are arranged in a line in a main scanning direction corresponding to the reading line, and the large number of photoelectric conversion elements are arranged at a predetermined position in the main scanning direction. a line image sensor that scans at a timing of a main body configured to be movable in a substantially perpendicular sub-scanning direction; and a main body configured to be movable in a substantially vertical sub-scanning direction; First and second speed detection means for detecting respective speeds, and each photoelectric conversion of the line image sensor during each main scan based on speed detection signals obtained from the first and second speed detection means, respectively. An element position detection means for determining the position of the element, and the position of each photoelectric conversion element during each main scan determined by the element position detection means and pixel information obtained from each photoelectric conversion element at that position. and image information correction means for correcting the image information.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of the main body of the scanning section, and FIG. 2 is a configuration diagram seen from the side. The entire scanning unit main body when viewed from the outside has an elongated shape. The top, left, right, front and rear sides of this box are made of a hard material such as metal or plastic, and are shaped to be easy to hold. Inside the bottom of the box, movable rollers 1, 2, 3, and 4 are provided at both ends, and rotate only in one direction. The surfaces of these rollers are treated to prevent slipping (for example, surface roughening) or are made of a material such as neoprene rubber. roller 1,
2, 3, and 4 are connected by rubber belts 5, 6, respectively. Rotary shaft encoders 7 and 8 are connected to one end of the roller 1 and one end of the roller 3 as first and second speed detection means, respectively, and take out voltages V1 and V2 proportional to the respective rotational speeds.

These voltages V1 and V2 are voltages that can be used to determine whether or not the scanning unit main body is moving evenly, and the voltages V1 and V2 are voltages that can be used to determine whether or not the scanning unit main body is moving evenly. and the second
This is the speed detection signal.

FIG. 3 is a sectional view of the main body of the scanning section. A light receiving section 11 and a lens 12 as a light receiving means are arranged downward in the center.
(For example, a self-cleaning lens) is attached to the side, and multiple light emitting parts (LED) 1 are attached to the side.
3 is installed. The light emitting section 13 illuminates the reading line on the document opposite to the light receiving section and the lens section, and guides the reflected light from the reading line on the document to the light receiving section 11 via the lens 12. The light receiving section 11 is provided with a row of photodiodes, which are independent photoelectric conversion elements, that are continuous in a straight line as a whole. The output signals of the photodiodes, which are these light-receiving elements, are sequentially read out by sampling, but since this line image sensing technique is well known, its explanation will be omitted here.

The signal read from the light receiving section 11 is then processed by the processing section 14.

A processing unit 14 determines the position of each photoelectric conversion element of the line image sensor during each main scan based on speed detection signals respectively obtained from first and second speed detection means provided at both ends of the scanning unit main body.
is detected.

FIG. 4 shows a specific processing method. In this embodiment, since the structure is such that no blurring occurs in the direction perpendicular to the scanning direction, an example of correction in the scanning direction will be shown.

The light receiving section includes a plurality of light receiving elements p1...p10...pn
These multiple light receiving elements are lined up in a straight line, and the sampling scan of each light receiving element is sufficiently fast compared to the change in voltages V1 and V2, that is, the sampling time from light receiving elements p1 to pn is the same for each. It should be fast enough to be considered as time. In this embodiment, the sampling rate, that is, p1 and p
The sampling time difference with 2 is 2 μsec.

With such a time, even with a 4kbit light receiving section, the time difference between the two ends, that is, the difference between tlp1 and t1pn, is
8mec, which is negligible compared to the change in voltages V1 and V2 obtained when scanning the main body of the scanning section manually, so that no problems arise due to sampling. If both ends of the scanning unit body do not move evenly due to manual scanning, the positions corresponding to the sample points p1 to pn at each time will be different, and the reproduced pattern will be distorted if no correction is made. It is necessary to correct the point value.

In this embodiment, zero-order interpolation is performed to simplify signal processing. In this zero-order interpolation, if data at the desired measurement point cannot be obtained, the data at the desired measurement point is calculated and interpolated from the data before and after the measurement point, and this interpolated value is either "0" or " 1).

For example, the data before and after the desired measurement point is "1".
In the case of "1", the interpolated data is "1", and "0"
In the case of "0", the interpolated data is "0".

Also, the data before and after the desired measurement point is "1" or "0".
Alternatively, in the case of "0" or "1", it is determined whether to set it as "1" or "0" according to a predetermined definition.

Hereinafter, a case where data at a desired measurement point cannot be obtained will be explained.

That is, the main body of the scanning section is manually moved and the actual coordinate position at each sampling point is determined from the voltages V1 and V2 representing the position signals. and,
The pixel data at this actual coordinate position is checked, and if the pixel data at two actual coordinate positions located on both sides of the ideal coordinate position are the same, this pixel data is taken as the data at the ideal coordinate position. Specifically, the processing unit 14 stores ideal reading positions from which data is taken every time the unit moves a predetermined distance. Find the actual coordinate position where the data was read. and,
2 located on both sides in the scanning direction of the light receiving element that read the data corresponding to this actual coordinate position.
The data at the two actual coordinate positions are examined, and the data at the ideal reading coordinate position located in the middle is interpolated using these two data.

If the above two pixel data are different, in this embodiment the data corresponds to "white", but "black"
(Print)". If you select "white" data, "white" will enter the boundaries of the reproduced pattern, causing some blurring. If you select "black (print)" data, "black" will enter the boundaries of the pattern that should be reproduced as white, causing some blurring. However, in either case, it does not significantly affect the reproducibility of character patterns.

As described above, the image information is corrected in the processing section 14 based on the position of the light receiving element determined by the light receiving element position detection means and the pixel information at that position.

Note that in this example, blurring in the direction perpendicular to the scanning direction was ignored, but if distortion of the reproduced pattern due to this blurring becomes a problem, a position detector (rotary shaft encoder) that detects the position in the blurring direction is used. ) may be added to shift the data from the light receiving unit by the amount of deviation from the ideal position.

[Brief explanation of the drawing]

FIG. 1 is an external view of a pattern reading device according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a sectional view thereof, and FIG. 4 is a diagram illustrating the principle of reading. In the figure, 1, 2, 3, 4... roller, 5, 6... rubber pad, 7, 8... rotary shaft encoder, 11... light receiving section, 12... lens, 13... light emitting section, 14... ...Signal processing unit, V
1, V2... scanning unit speed, p0 to pn... light receiving element position of the light receiving unit.

Claims (1)

[Scope of Claims] 1. A pattern reading device that reads an arbitrary pattern on a document and converts the pattern information into electrical image information, comprising: a light emitting unit that irradiates a reading line on the document with light; A large number of photoelectric conversion elements that receive reflected light from an upper reading line are arranged in a line in a main scanning direction corresponding to the reading line, and the plurality of photoelectric conversion elements are arranged at a predetermined timing in the main scanning direction. a line image sensor that converts pattern information on the read line into an electrical signal for each main scan, the light emitting means and the line image sensor, and the line image sensor is mounted substantially perpendicular to the main scanning direction of the line image sensor. a main body configured to be movable in a sub-scanning direction; and a main body disposed at both ends of the main body in a direction parallel to the main scanning direction of the line image sensor; first and second speed detection means for detecting speed; and detection of each photoelectric conversion element of the line image sensor during each main scan based on speed detection signals obtained from the first and second speed detection means, respectively. element position detection means for determining the position; and the position of each photoelectric conversion element during each main scan determined by the element position detection means and pixel information obtained from each photoelectric conversion element at that position. A pattern reading device comprising: image information correction means for correcting image information;