JPH02264566A - Picture reader - Google Patents

Abstract

PURPOSE:To prevent such a defective case that the boundary part and the periphery of an original and blackened by using a area which is reckoned as white by a reckoning mean as a frame erasing area. CONSTITUTION:An image sensor 1 scans an original by one line every time a horizontal synchronizing signal is received and outputs a picture signal proportional to the light quantity. The picture signal is corrected by a shading correction circuit 2, and a binarizing circuit 3 changes the white level and the black level of the binary signal data into '1' and '0' respectively. The binary data is inputted to a shift register 5 and an AND gate 6 outputs 1 when all outputs of the register 5 are equal to 1. An F/F 7 is cleared by a clear signal right before a reading action of one line starts. The output Q is kept to '1' before the white data is read in 8 continuous picture elements. Thus the output of an OR gate 8 is set to '1'. In such a way, a reckoning means I reckons all areas as white before 8 continuous picture elements are white from the beginning of the main scan of a read area. Then these areas reckoned as white can be used as the frame erasing areas.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an image reading device.

[Conventional technology]

Conventionally, J! This prevented the border and periphery of 1M from becoming black (hereinafter simply referred to as frame erasure).

A conventional example of the above frame erasing will be explained with reference to FIGS. 7 and 8.

FIG. 7 is a plan view showing a conventional example of frame erasing, and FIG. 8 is a plan view showing the state after the frame eraser in FIG.

In FIG. 7, 100 is a reading area, 101 is a document, 102 is an image, and 103 is an area where the reading device of the prior art example described above erases images.

Next, the operation of this conventional example will be explained. In FIG. 7, a document 101 having an image 102 is arranged diagonally with respect to a frame erasing area 103 prearranged in the reading area 100 as shown in FIG.
If it protrudes further, the result of reading the mound is the 8th.
As shown in the figure, the four corners of the image disappear, and the original 10
The border of 1 and the four corners around it become black.

[Problem to be solved by the invention]

As mentioned above, in the conventional example, when performing a smart eraser,
w, the border of M4 may protrude from the area that the above-mentioned image reading device considers to be a white background, and on the other hand, if the area considered to be a white background is enlarged, there is a risk of erasing the image in the document that should be read. There was a problem with the size.

This invention was made to solve the above-mentioned problems, and provides an image reading system that uses an inexpensive circuit configuration, does not erase the original image, and prevents the border and periphery of the original from becoming black. The purpose is to obtain equipment.

(Means for Solving the Problems) Therefore, in the present invention, in the image reading bag j6 that images the reflected light from the document illuminated by the light source on the photoelectric conversion means and reads the image, There is a viewing method (1) that considers all pixels from 1 to several consecutive pixels until they become white as white, and the area that is considered white by the viewing method (1) is set as a clean-cut area. This aims to achieve the above objective.

Further, the above-mentioned invention has a viewing means (TI) that considers a point where several pixels in succession are white going back from the end of the main scanning of the reading area to a point where the pixels are white, and the viewing means (U) This is intended to achieve the above objective by making the area considered to be white into a blank area.

Further, in the above invention, the above object is achieved by providing a document holding means that has a low reflectance or does not cause diffused reflection.

(Operation) The image reading device according to the present invention has an image reading device of the present invention.
), all pixels from the beginning of the main scan of the reading area until several pixels in succession become white are considered to be white, and this area that is considered to be white is set as the frame erasing area.

Further, the image reading device according to the present invention includes a viewing means (I).
According to I), the area from the end of the main scan in the reading area up to a point where several pixels in succession are white is regarded as white, and this area regarded as white is set as a blank area.

Further, in the image forming apparatus according to the present invention, the photoelectric conversion means can read the portion of the original holding means as white because the original holding means has a low reflectance or does not reflect diffusely.

〔Example〕

The two aspects of this invention will be explained below based on the drawings.

FIG. 1 is a block diagram showing the basic structure of an electric circuit according to a first embodiment of the present invention, FIG. 2 is a side sectional view showing the internal structure of an image reading device of the present invention, and FIG. 3 is an image of the image shown in FIG. An external view of the reading device, FIG. 4 is a basic configuration diagram of an electric circuit according to a second embodiment of the present invention, FIG. 5 is a side view showing a reproduced image according to the first embodiment, and FIG. FIG. 7 is a plan view showing a reproduced image according to an example. FIG. 7 is a plan view showing a state in which a document is disposed diagonally with respect to the reading area. First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

This first embodiment erases the frame only at the beginning of the main scanning of the reading area.

In Figure 1 of the drawing, 1 is a photoelectric conversion sensor (image sensor), and the photoelectric conversion elements (not shown) of the image sensor 1 are arranged in a straight line, and each time it receives an HSYNC (horizontal synchronization) signal, it scans the original one line. It scans each step and outputs an image signal proportional to the amount of light. 2 is a shading (pseudo signal) correction circuit, and the image signal from the image sensor is corrected for variations in the light beam that illuminates the document in the shading correction circuit 2, and then converted into binary signal data in the binarization circuit 3. is converted to In this embodiment, the bell is set to ``1'',
The black level is set to “0”.

4 is the binarized data output from the binarization circuit 3, 5 is a shift register, and 6 is an AND gate, which outputs "1" when all outputs of the shift register 5 are 1'. 7 is an F/F (flip-flop circuit), and the output of F/F 7 is “L” until 8 pixels are continuously read as own data in the image sensor 1, and the output of the OR gate 8 is always “1”. Let it be. (1) is a viewing means, and the viewing means (I) is composed of a shift register 5, an AND gate 6, and an F/F 7, and the viewing means (I) is composed of a shift register 5, an AND gate 6, and an F/F 7. This is a way to treat everything up to the point of becoming white as white. In addition, in Figure 2 of the drawing, 9 is the manuscript, P
Reference numeral denotes document holding means, which is composed of a document holding cover 10 that has a sufficiently low reflectance or does not reflect diffusely. The manuscript 9 is illuminated by a fluorescent lamp 11 that is slightly longer than the width of the manuscript, and the brightest straight areas on the manuscript are 1st, 2nd, 27th, 15th, 16th, and 16th, respectively. An image is formed on the light receiving surface of the image sensor 1 (FIG. 1) via the third mirror and the lens 19.

Here, the angles formed by the second mirror 15 and the third mirror 16 are fixed at right angles, and the angles formed by the second mirror 15 and the third mirror 16 are fixed at right angles.
2, and the optical distance from the surface to be read to the lens 19 is kept constant.

Next, the operation of this first embodiment will be explained with reference to FIGS. 1 and 2, focusing on the viewing means (I).

As described above in FIG. 2, the r! The reflected light from the original document 9 is imaged on the photoelectric conversion sensor 1 and read. Next, in FIG. 1, the aforementioned photoelectric conversion sensor (image sensor) 1 scans the original 9 line by line every time it receives the H5YNC (horizontal synchronization) signal and outputs an image signal proportional to the amount of light. The shading correction circuit 2 corrects the signal, and the binarization circuit 3 converts the white level of the binary signal data to "1" and the black level to "0". This binary data is input to the shift register 5 and output to the AND gate 6 as shown. In this case, the AND gate 6 indicates that all the outputs of the shift register 5 are “
1", F/F7 is cleared by φSH (φ level clear signal) just before reading one line starts, and the output Q remains "1" until white data is read for 8 consecutive pixels. 1" and makes the output of OR gate 8 always 1. When white data is read for 8 pixels consecutively, F/
F7 is set and the output of OR gate 8 is equal to binary data.

As described above, the recognition means (I) considers all of the reading area from the beginning of the main scan to 8 consecutive pixels as white, and sets this area that is considered white as the frame erasing area. can do. FIG. 5 shows image reproduction according to the first embodiment, in which frame erasure is performed only on the first side of the main scan (left side in the figure) of the reading area 100 without erasing the original image, and the border and periphery become black. This can be done by preventing

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 6, focusing on the viewing means (rl). In this second embodiment, frames are erased on both sides of the main scanning area of the reading area.

In Figure 4 of the drawing, the same symbols as in Figure 1 are the same,
In addition, 21 is a RAM (random memory) in which data is written every line, outputs 1 bit of data for each address generated by the main scanning counter 23, and outputs new data. Remember. 24 is an F/F that holds data when reading of a certain line is completed, 25 is an F/F
/F F/F that latches the output of 24, 26 is RAM2
A comparator (!I) for comparing the main scanning address A from the F/F 25 with the main scanning address A from the F/F 25 is an evaluation means, and the evaluation means (n) is the RAM 21° main scanning counter 23. F/F24. It is composed of an F/F 25° comparator 26, and is a means for determining that a point where several pixels in succession were white going back from the end of main scanning in the reading area is white.

Next, the operation of this embodiment will be examined using FIG.
The explanation will focus on

In FIG. 4, the process from the image sensor 1 to the generation of binary data output from the OR gate 8 and the shift register 5. The operation of the evaluation means (I) consisting of the AND gate 6 and the F/F 7 and the OR gate 8 is the same as in the first embodiment, and the output of the OR gate 8 is such that the first point in the main scan is white data. has been converted.

The data is written into the RAM 21 for each line of scanning. Here, the RAM 21 outputs 1-bit address data for each address generated by the 1-scan counter 23, and then stores new data. In other words, R
The output of AM21 becomes the address data of the previous line.

F/F 25 is the F/F when reading a certain line is finished.
Since the output of F24 is latched, F/F
The address data held in No. 25 is the largest among the main scanning addresses in which eight consecutive pixels were white in the previous line, that is, the point closest to the end of the read line.

In the range from this point to the end of the read line, the controller i(lator 26 outputs 1), and the output of the OR gate 22 is forced to be "1".

As mentioned above, the recognition means (II) considers the reading area from the end of main scanning to a point where 8 consecutive pixels are white to be white, and this area is determined as white. can be used as a frame-erased area. By erasing the frame by this viewing means (11), it is possible to erase only the last side of the main scan of the reading area.

The second embodiment includes the consideration means (1) and (IT) as described above.
), as a result, as shown in FIG. 6, the entire frame can be erased without erasing the entire image of the document, preventing the entire border and periphery from becoming black.

Incidentally, in the above embodiment, the document was judged based on eight consecutive pixels of white data, but it goes without saying that the number of pixels is not limited to this, and the optimum value is adopted depending on the reading resolution and the like.

C) Effects of the Invention) As described above, the present invention provides an image reading device that uses an inexpensive circuit configuration and can prevent the edges and periphery of the document from becoming black without erasing the image on the document. There are effects that can be obtained.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of an electric circuit in a first embodiment of the invention, FIG. 2 is a cross-sectional view showing the internal configuration of the image reading device of the invention, and FIG. 3 is a diagram of the image reading device of FIG. 2. An external view, FIG. 4 is a basic configuration diagram of an electric circuit according to a second embodiment of the present invention, and FIG. 5 is a plan view showing a reproduced image according to the first embodiment.
FIG. 6 is a plan view showing a reproduced image according to the second embodiment;
The figure is a plan view showing a state in which a document is arranged diagonally with respect to the reading area, and FIG. 8 is a plan view showing a reproduced image by a conventional image reading device. (I), (rl)...Measurement means 4...
Binary data 9... Original 10... Original holding cover 14... Fluorescent lamp holder 17... Sensor board 20... Main board 28 ......Reflector 100...Reading area 101...Document 102...Image 103...Frame erasure area of conventional example , the same reference numerals indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In an image reading device that images reflected light from a document illuminated by a light source on a photoelectric conversion sensor and reads it, all pixels in the reading area from the beginning of the main scan until several pixels in succession turn white are considered white. 1. An image reading device comprising a viewing means for determining white, and forming an area deemed to be white by the viewing means as a frame-erased area. (2) It has a recognition means that considers as white the area from the end of the main scan of the reading area up to a point where several pixels in succession were white, and the area considered as white by the recognition means is provided. 2. The image reading device according to claim 1, wherein the image reading device is formed as a frame-erased area. (3) The image reading device according to claim 1 or 2, further comprising document holding means that has a low reflectance or does not reflect diffusely.