JPS6188657A - Picture reading method - Google Patents

Abstract

PURPOSE:To obtain a picture subject to speed correction at the start of sensor input by using a preset constant speed as the first detecting speed so as to start reading when the first or second sensor detects a black picture element at the start of input. CONSTITUTION:A character 2 on an original is read by operating manually a device where at least two image sensors such as 1st and 2nd sensors 5-1, 5-2 are arranged in the manual feeding direction in a prescribed interval. Suppose that the sensor 5-1 is on the character 2 at the start of reading and the picture started for input is corrected when the black picture element is detected. A caption m0 is a prescribed value decided by the system in advance and when a black level is detected by the sensor 5-1 at the start of read, the speed is detected newly at a time t1 and the speed correction by the thinning processing of m0 m is applied until the detection speed (m) is decided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to an image reading method that enables photoelectric conversion signals to be obtained from characters, figures, etc. written on a manuscript by manual feeding operation. It is.

[Conventional technology]

The conventional image reading method using two one-dimensional image sensors has been replaced with a third one in a manual-feeding reading device.
As shown in the figure. In this figure, 1 is a manuscript, and 2 is characters, figures, etc. written on the manuscript 1 (hereinafter simply referred to as characters). 3 is a lens optical system that uses a single spherical lens and a converging fiber eye.

4 is a light source for illuminating the original, and a solid light source such as a tungsten lamp or LED is used. 5-], 5-2 are each 1
The first and second sensors (hereinafter simply referred to as sensors) are composed of dimensional image sensors, and are thin film photoelectric conversion elements such as CdS and Se, or CCDs.

A Si element such as a MOS is used.

Due to the movement indicated by the arrow 6, the sensor 5-1.5-2 becomes V
The character 2 (for example, "A") written on the document 1 is read through the lens optical system 3 (.

The interval 1 between the reading positions 5-1 and 5-2 on the original 1 is the size of the characters 2 written on the original 1.

It is determined by the letter spacing and the magnification of V's.

4(a) and 4(b) show a reading method using this type of apparatus, and the same parts as in FIG. 3 are represented by the same reference numerals. When sensors 5-1 and 5-2 are arranged at intervals l and scanned in the direction of arrow 6, FIG. 4(a) shows the movement state when 6" is detected by sensor 5-1, Figure (b) shows the moving state when "black" is detected by the sensor 5-2.

When changing from the state shown in Fig. 4(a) to the state shown in Fig. 4(b), the required number of sensor scans n is expressed as n = N 6 X l, where No is the fineness in the direction of movement. . From this figure 4 (&) to (b), if the actual number of scans during manual feeding when moving by K is Vm, is the image corrected by converting from m lines to n lines by thinning the image? can get. Sara K.

Even after the state shown in FIG. 4(b), by performing the same processing assuming that the moving speed V is constant, only character 2 can be read.

[Problems that Kokyo attempts to solve]

In the conventional image reading method as described above, if the first sensor or the second sensor detects a black pixel before starting reading, the speed cannot be detected correctly and an image without speed correction is obtained.

This method has been developed to eliminate these drawbacks, and the purpose is to provide an image reading method that can obtain a speed-corrected image at the start of sensor input.

[Means for solving problems]

In the image reading method according to the present invention, when the first sensor or the second sensor detects a black pixel at the start of input, reading starts at a constant speed preset in the system as the first detection speed. .

[Effect]

In this invention, at the start of input, the first or second
When a black pixel is detected, reading is started using a constant speed preset in the system as the initial detection speed.

〔Example〕

FIGS. 1(a) and 1(b) show an embodiment of the present invention. In FIG. 1(a), the sensor 5-1 is above the character 2 at the reading start pressure, and the black pixel is Detection [-] is shown. FIG. 1(b) shows a method of correcting an image inputted from this state, where T is the sensor 5.
-1 input signal; 7' is the input signal of the sensor 5-2;
8 is a corrected image. mQ is a constant value determined in advance by the system.

If black is detected by the sensors 5- and 1 at the start of reading, then a new speed detection is performed at time t, and speed correction is performed by thinning processing of mo-n until the detected speed m is determined. do.

FIG. 2 shows an example of a circuit implementing the invention. In this figure, 9-1.9-2 is a black and white change detection circuit, 10
1 is an image reading start switch, 11 is a black pixel detection circuit at the time of starting reading, 12 is a speed detection circuit, and 13 is a speed correction circuit.

The input of the image of the sensor 5-1.5-2 is started by the image reading start switch 10, and at that time, whether or not there are black pixels is detected by the black pixel detection circuit 11 at the time of starting reading,
If so, the speed detection circuit 12 is informed of the detection of a constant speed. After that, black and white change detection circuit 9-1.9-2
From 1C, speed detection is performed by the speed detection circuit 12 according to the timing of the change between white and black, and from the above results, an image whose speed has been corrected by the speed correction circuit 13 is obtained.

Note that in this invention, the means for speed correction itself may be a conventional technique, so a specific example thereof is omitted.

〔Effect of the invention〕

As explained above, the present invention provides the first sensor or the second sensor.
When the sensor detects a black pixel at the start of input, the system starts reading at a preset constant speed as the first detection speed, so
Even if a black pixel is detected at the start of reading, the read image can be corrected according to a predetermined speed, so even if the sensor is not at the 11th mark at the start of reading, it will still be able to detect a pixel that has been sufficiently corrected. The advantage is that you can get a full-length image.

[Brief explanation of drawings]

Figures 1 (a) and (b) are diagrams showing the relationship between a sensor and characters, and a diagram showing an image correction method, showing one embodiment of this invention, and Figure 2 is a circuit implementing the present invention. FIG. 3 is a block diagram showing an example of the conventional image reading method, and FIGS. 4(a) and 4(b) are diagrams showing the relationship between the sensor and characters in FIG. 3. In the figure, 1 is a document, 2 is a character, 3 is an optical system, 4 is a light source, 5-1 is a first sensor, 5-2 is a second sensor, 6
is an arrow, 7.7' is an input signal, and 8 is a corrected image. Figure 2 Figure 3, Figure 4

Claims (1)

[Claims] By hand-feeding a device in which at least two image sensors, a first sensor and a second sensor, are arranged at regular intervals in the hand-feeding direction, characters, figures, etc. written on a document illuminated by a light source can be detected. In the image reading method, the speed is determined from the timing when the first sensor, which is advanced in the hand-feeding direction, detects a point of change from white to black, and the second sensor detects a point of change from white to black at the same position. When the first sensor or the second sensor detects a black pixel at the start of input when obtaining an image whose speed is corrected by signal control based on the detected speed, the system detects a black pixel in advance. An image reading method characterized in that reading is started using a set constant speed as an initial detection speed.