JPS63114454A - Image processor - Google Patents

Abstract

PURPOSE:To automatically sort out information on the effective images of an original by placing a mark on an original platen and detecting the mark. CONSTITUTION:The discrimination mark 302 is stuck in a position adjacent to the tip of an original on the back of an original reference index plate 120. If contents that a CPU reads in a main scan direction show that there is a black level (discrimination mark 302) following a white level(1st position), and that the black levels continue, followed by the white level(2nd position), the 1st position denotes a read start position and the 2nd position denotes a read end position. In a subscan read start position, a line next to a line where black level information exists is a read start position. At that time, the number of lines from a one where an original lighting unit 115 is detected to the read start position is stored. At the time of reading the original, lines behind the number are regarded as effective image information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing apparatus that reads a document placed on a document table.

[Prior Art] In recent years, with the development of information processing technology, image processing by computers has become common. Among these image processing methods, various methods have been proposed as manual image processing methods, including image scanners (hereinafter referred to as
Image reading devices called CODs have become rapidly popular in recent years because they are small, easy to handle, and inexpensive.

When reading a document with this type of device, the adjustment of the document reading start position in the main scanning direction for reading is performed by focusing the image on the document reference digit (center of the maximum document width indicated on the plate surface) on the CCD. The center of the original image was aligned.

[Problems to be Solved by the Invention] In making this adjustment, a document written in accordance with the instructions on the document reference index board is read, image information of the document is formed into an image by another device, and an image is formed based on the formed image. lens and C
I had to move the CD position 8 times and make adjustments many times.

Furthermore, in the sub-scanning direction, it is necessary to adjust the position of the verification unit position detection sensor with respect to the document reference index plate so that the verification unit is located below the document reading start position. I didn't have to go through a tedious process.

The present invention has been made in view of the above-mentioned prior art,
An object of the present invention is to provide an image processing device that has a simple configuration and can read the entire area of a document written in accordance with the instructions of a document reference index board.

Means for Solving Problem L] In order to solve this problem, the present invention has the following configuration.

That is, a mark provided on a document table for reading an image, a reading means for reading an image on at least a wider area than the document table, and a detection means for detecting a density change due to the mark in the read image. Be prepared.

[Function] In the configuration of the present invention, the detection means detects a density change in the image data read by the reading means, and the detected position is set as the reading reference position of the reading means. .

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Explanation of the basic operation of the image reading device (Fig. 3)] Fig. 3 shows the main unit 4 for explaining the basic operation of the image reading device.
(This is a top view of 9 parts.

In the figure, 101 is the main body of the document reading device, in which a document 11 is sandwiched between a transparent platen glass 117 and a platen cover 119 that can be opened and closed in the direction of arrow C around a fulcrum 106.
8 is set with its recording surface facing down. lamp 20
The original illumination unit 115 having the original 118
The recording surface of is illuminated, and the reflected light passes through an optical path 105 and forms an image on a C0D (charge coupled device) 112. The optical path IQ5 passes through reflection mirrors 102 to 104 and a lens 114, but in order to input the secondary surface image of the original f height 118, the original illumination unit 115, the reflection mirror 102, and the reflection mirrors 103 to 104 are located on the left and right sides of the figure. It is designed to move eight times in the directions (directions of arrows A and B) (this eight-shift direction is the sub-scanning direction).

In addition, for image input in the direction perpendicular to the page, a large number of image sensors in the CCDlI2 are provided in the direction perpendicular to the page to form a line-type image sensor, which electrically scans the original image signal obtained by imaging. (this direction is the main scanning direction).

113 is a CCD driver that controls the CCDI 12;
11 is a control unit that controls the entire image reading apparatus main body 101, and 121 is a detection sensor that detects the starting position (home position) of the original illumination unit 115.

Incidentally, reference numeral 120 denotes a document reference index plate which constitutes the main part of the present invention, and its explanation will be described later, but in the past, it was simply the document 118.
It indicated the position to set the .

[Description of Circuit Configuration (FIG. 2)] FIG. 2 is a block diagram of the main parts showing the circuit configuration of this embodiment.

First, the document illumination unit 115 in FIG.
21 is rotated nine times in the direction of arrow B until it detects the document illumination unit 115. When the CPU 217 learns that the original illumination unit 115 has been detected by the sensor 121, it stops the original illumination unit 115. After this, lamp 20
1 is turned on to move the document illumination unit 115 in the direction of the arrow, that is, in the sub-scanning direction for one line.

Image information' obtained by irradiation with the lamp 201 is imaged onto the CCDI 12 through the lens 114. The imaged information is optical-to-electrically converted by the COD driver 113, sent to the AMP 204 and amplified, and then further converted from an analog value to a 4-bit digital value by the A/D converter 205, and then sent to the shading correction circuit 20.
After the image information in which the light intensity changes due to the angle of incidence on the lens 114 is corrected in step 7, the image is backed up into 1 byte and 2 pixels in the 4-bit shift register 210.

The backed 1-byte information is stored in address counter 2.
RAM through selector 212 to the address specified by 08.
209. The image information in the main scanning direction that is sequentially shifted and output from the CCD 112 is stored one after another in the RAM 209 in the same procedure as described above.

Next, the CPU 217 reads one line of image information stored in the RAM 209 one byte at a time and determines whether it is a white level or a black level.

[Description of Discrimination Mark (FIG. 1)] FIG. 1 is a diagram showing the back side of the original reference index plate of this embodiment. On the back side of the original reference index plate 120, there is a discrimination mark at a position adjacent to the leading edge of the original 118. 302 is provided. The discrimination mark 302 has a length corresponding to the maximum document width, and this mark is determined as image information as a black level.

In the content read out in the main scanning direction by the CPU 217, there is a black level next to the white level (referred to as the first position).
However, if this black level is continuous and then the white level is present at the second position), that is, if it is determined to be a discrimination mark,
This first position indicates the reading start position, and the second position indicates the reading end position. The document width is from this reading start (position) address to the reading end (position) address, and when reading the document, the image information from the reading start address value (COD drive count value) to the reading end address value is All you have to do is transfer it to an external device.

Further, at the sub-scanning reading start position, the line next to the line where the black level information (discrimination mark) exists (because the discrimination mark is present on the document reference index board side) becomes the reading start position. At this time, the number of lines from the time when the document illumination unit 115 is detected to the reading start position is stored, and when reading the document, the number of lines after the number of lines becomes effective [ii information].

The above description has been made regarding the case where storage processing is performed using 4 bits of halftone information, but when processing binary image information that does not require halftone information, the binarization circuit 218 is used to store information of 1 bit per pixel. The shift register 211 backs up 8 pixels in 1 byte and transfers it to the RAM 2 through the selector 212.
09 and read out the written contents by the CPU 217. In this case as well, valid image information of the original can be selected using the same method as described above.

Incidentally, 216 is an oscillator, and the clock obtained by this is processed into a suitable lock by a timing signal generation circuit 215 and becomes a reference clock for timing control of each part.

220 is a ROM in which a basic operating program (firmware) for the CPU 217 is stored. 213 is an output selector that selects the image information obtained from the CCD 112,
Halftone output or binary output is selected by a signal from CCD 112, and either one is output to interface circuit 214.

FIG. 4 is a flowchart for explaining a series of operations of this embodiment, and this operation program is based on the R
This is stored in the OM220.

First, when reading a document is started, in step S1, the document illumination unit is returned to the home position. In this work, as shown in step S2, the document illumination unit is moved until the detection sensor is turned on. After moving to the home position, turn on the lamp of the document illumination unit in step S3 and move one line in the sub-scanning direction (
At this point, main scanning is performed to read one line of image information (step S5). Next step S6
Then, it is determined whether or not there is a discrimination mark in the image information of the read line, and if there is no discrimination mark, steps 54 to S6 are repeated until a discrimination mark is obtained.

When the discrimination mark is detected in step S6, effective image information in the main scanning direction is determined based on this discrimination mark (step S7). Regarding the sub-scanning direction, effective image information is determined from the next line of the discrimination mark (step S8). From then on, by repeating the selective transmission of the effective image information determined in steps S7 and S8 according to steps 89 to 312, It becomes possible to selectively extract only the effective image information of the original.

In the present invention, the length of the discrimination mark is set to be the same as the maximum main scanning width of the document, but in principle, it is sufficient if there is a function that can determine the starting point of the document.For example, if the discrimination mark is set in the main scanning direction, 1024 pixels after detection is the maximum main scan I of the original
Even if we specify ``l','' and try to find this by calculation, 4R will not be obtained.

[Effects of the Invention] As explained above, according to the present invention, by placing a mark on the document table and detecting this mark, effective image information of the document can be automatically selected. Since it is no longer necessary to strictly align the lens and COD and the detection sensor with respect to the reference index plate, it is possible to significantly simplify the assembly and adjustment work.

In addition, since valid image information of the document is automatically selected inside the device every time document reading is started, stable valid image information can always be obtained without being affected by changes in the device over time or external forces.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the back side of the document reference index board of this embodiment, Figure 2 is a block diagram of the main parts showing the circuit configuration of this embodiment, and Figure 3 is a diagram showing the main parts for explaining the operating principle of the image scanner. A side view of the mechanism section, FIG. 4 is a flowchart for explaining a series of operations of the embodiment according to the present invention. 101... Image scanner body, 111... Control unit, 112... CCD, 113... CCD
Driver, 114...Lens, 118-Document, 120
... Original reference index plate, 121 ... Detection sensor, 20
1...Lamp, 209...RAM, 217...C
P.U. 220... ROM, 302... Discrimination mark. Patent applicant: Canon Co., Ltd.

Claims (2)

[Claims] (1) A mark provided on the manuscript table for reading the image,
A reading means for reading an image on an area wider than at least the document table, and a detection means for detecting a density change due to the mark in the read image, and the reading means detects a position where the density changes detected by the detection means. An image processing device characterized in that the reading reference position is a reading reference position of a means. (2) The image processing apparatus according to claim 1, wherein the reading reference position is a reading start position in the main scanning direction and the sub-scanning direction.