JP2862235B2 - Document processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a document processing apparatus for processing a document. [Prior Art] Conventionally, it has been proposed to detect a placement position of a document placed on a platen and a size of the document. Further, when information is recorded only on a part of the document, information corresponding to a blank portion other than the information portion is wasted. However, simply recognizing the position and size of the document as described above causes the output image information to include waste information even if the image information obtained by reading the document is extracted based on the position and size. Further, as described in Japanese Patent Application Laid-Open No. 61-242458, a configuration has been proposed in which the position of an information portion in a document is detected and a document image is processed in accordance with the detection result. However, in the configuration described in this publication, the position of the information portion in the document is detected using the entire surface of the document table as a detection target area, and if the document table or the document pressing plate is dirty, It may be erroneously recognized that an information portion exists outside the position of the original on the platen, and the output image information may include waste information. [Purpose] The present invention has been made in view of the above points. An object of the present invention is to reliably detect an information portion in a document and appropriately process a document image based on the detection result. A document table on which a document on which the document is recorded is placed, reading means for scanning the document placed on the document table, and the entire surface of the document table as a detection target area, based on an output signal from the reading means First detecting means for detecting a plurality of coordinates corresponding to a plurality of vertices of the document, and detecting a mounting position of the document on the document table defined by the plurality of coordinates detected by the first detecting means. A second detecting means for detecting a plurality of coordinates corresponding to a plurality of vertices of an information portion in the document based on an output signal from the reading means,
A document processing apparatus for processing a document image based on a plurality of coordinates corresponding to a plurality of vertices of an information portion in the document detected by the second detection means. EXAMPLES Hereinafter, the present invention will be described based on preferred examples. FIG. 1-1 shows an external view of a document reading apparatus to which the present invention is applied, and FIG. 1-2 shows a cross-sectional view. The document is placed downward on the platen glass 3 and pressed down on the glass 3 by the document cover 4. The original platen glass side of the original cover 4 is mirror-finished for original detection described later. The original is irradiated by the fluorescent lamp 2 and the reflected light is condensed on the surface of the CCD 1 via the mirrors 5 and 7 and the lens 6. The mirrors 7 and 5 move at a constant speed while applying a PLL by a DC servomotor at a relative speed of 2: 1. Thus, the image of the entire original is photoelectrically read by the CCD 1 sequentially for each line. The maximum document size that can be processed by this document reading device is A3 size, and the resolution is 400 dots / inch.
The number of 1 bits requires 4678 (= 287 / 25.4 × 400) bits. Therefore, the present device uses a 5000-bit CCD in which about 5000 photoelectric conversion elements are arranged in a line. If the main scanning cycle is 352.9 μsec (= 10 ⁶ /180×25.4/400), the optical system composed of the mirror 7 and the lamp 2 at the same magnification is 180 m
It moves at a speed of m / sec. FIG. 2 is a system block diagram of the document reading apparatus. The CCD reading unit 301 includes a CCD, a clock driver for the CCD, a signal amplifier from the CCD, and an A / D converter for A / D converting the signal. Image data converted into a 6-bit digital signal is output from the CCD reading unit 301, and a shading correction unit 302 is output.
Is input to A shading correction unit 302 detects a shading amount of a light source and a lens included in the image data and removes the shading amount from the image data.
After performing the correction, the image data is stored in the shift memory unit 303.
Is stored temporarily. The shift memory unit 303 has two lines of shift memories. When the image data of the Nth line is written in the first memory, the image data of the (N-1) th line is read from the second memory. The shift memory unit 303 also includes a write address counter for writing image data to the shift memory, a read address counter for reading, and an address selector circuit for switching address signals from the two counters. Details are shown in FIG. Further, the scaling / movement processing unit 304 changes the clock for writing image data to the shift memory and the clock for reading from the shift memory and the timing for reading the image data, thereby performing image scaling and movement in the main scanning direction. The image data output from the shift memory unit 303 is input to the density processing unit 305, where the image data is subjected to binarization processing and dither processing to become a binary signal, which is output to the trimming processing unit 306. The trimming processing unit 306 forcibly processes an arbitrary section of the main scanning line image data into “0” or “1”, and performs image editing such as trimming of a desired area image and masking of an unnecessary image. Further, the binary signal output from the trimming processing unit 306 is also input to the document position detection unit 307. Here, the position coordinates of the document on the platen glass 3 and the information portion in the document are detected using the binary signal. The CPU unit 308 includes a CPU, a ROM, a RAM, a timer circuit, and an I / O interface. The CPU unit 308 controls the operation unit 310, and controls operation of each unit according to settings from an operator using the operation unit 310. And a device for outputting image data, such as a printer, is controlled by serial communication. Reference numeral 311 denotes a DC servo data driver which controls the speed of the motor 315 according to the speed data in accordance with the magnification preset by the CPU 308. A fluorescent lamp driver 312 controls on / off of the fluorescent lamp 316 and control of the amount of light when the fluorescent lamp 316 is turned on. 313,314
Is the position of the optical system consisting of the lamp 2 and the mirror 7
08 is a position sensor to know. An external unit (output device of image data) such as a printer is connected via a connector JR1 and a connector JP1 of the external unit. Then, control signals required for serial communication such as image data communication and commands are exchanged between the apparatus and the external unit. In the clock generator 309, the transfer clock of the CCD signal and the read / read of the shift memory are synchronized with the horizontal synchronization signal.
A light clock or the like is generated. As a horizontal sync signal,
For example, BD synchronized with image recording of each line from printer
(Beam Dececc) signal may be received, or may be generated internally without being supplied from the outside. FIG. 3 shows a circuit diagram of the second illustrated shift memory unit 303. For simplification of description, one of the two shift memories will be described. Write address counter
Reference numeral 904 denotes an address counter for writing data to the shift memory 907, and read address counter 905 is an address counter for reading data from the shift memory 907. The address selector 906 receives a command from the CPU 308 via the I / O port 901 and selects either the address signal of the write address counter 904 or the address signal of the read address counter 905 to address the shift memory 907. It is. The I / O registers 902 and 903 are a write address counter 904 and a read address counter 905.
Is a register for the CPU 308 to give a preset value to each. The write address counter 904 and the read address counter 905 are both down counters, each of which receives a WST signal and an RST signal for instructing the start of a count operation, and outputs a write clock WCLK to the shift memory and a read clock RCLK from the shift memory. Is entered. 915 and 916 are exclusive OR gates for determining the image area, OF is a signal for controlling it, and when "1", ST counter
912, determined by EN counter 913. The inside of the frame is masked, the outside of the frame is set as the output image, and the time frame of “0” is set as the output image, and the outside of the frame is masked. Reference numeral 910 denotes an output from the shift memory 907, and a density processing unit 908.
Is an AND gate for controlling the output of image data that has been converted into a binary signal, 917 is an AND gate for determining whether to output the mask portion as white or black, and PB is a signal for controlling the mask portion. When "1", black is output, and when "0", white is output. 911 converts the image data output by gates 910 and 917 to VI
An OR gate for outputting as DEO, 909 is an exclusive OR gate for controlling black-and-white inversion of image data, IN is a signal for controlling the same, and when it is 1, it is the original image and when it is 0, it is inverted. Each signal is output by the CPU 308 in the mode specified by the operator. An ST counter 912 and an EN counter 913 are a start bit counter and an end bit counter for outputting an image only to a predetermined area, respectively.
PU308 presets the count data for the gate. The flip-flop 914 is set at the count-up of the ST counter 912, and reset at the count-up of the EN counter 913. Fig. 7 shows ST counter 12, EN counter 913
Shows the operation when the image data in the frame determined by the above is output and the outside of the frame is masked as white. That is, when the OF signal is “0”, the F / F
When the Q of "1" becomes "1", the output of the gate 915 becomes "1", and from that point on, the gate 910 outputs the input image data until the EN counter 913 counts up. on the other hand,
Outside the output period of the image data, the output of the gate 916 is "1", so when the BB signal is "0", the output of the gate 917 is "0", and the gate 911 outputs "0", which becomes a white mask. . Conversely, when OF = "0" and BB = "1", the outside of the frame is black masked. When OF = 1, the gates 915, 916 are used from the count up of the ST counter 912 to the count up of the EN counter 913.
Are “0” and “1” during that time, so BB =
When "1", the inside of the frame is masked black, and when BB = "0", the inside of the frame is masked white. FIG. 4 shows a circuit diagram for detecting coordinates in the second illustrated document position detecting unit 307. In addition, FIG.
The original ORG placed on top is shown. The main scanning counter 351 is a down counter, and indicates a scanning position in one main scanning line. This counter is set to the maximum value in the main scanning direction (X direction) by the horizontal synchronization signal HSYNC, and counts down every time the image data clock CLK is input. The sub-scanning counter 352 is an up counter, and is set to “0” at the rising edge of VSYNC (image leading edge signal).
The count value is incremented by the HSYNC signal to indicate the scanning position in the sub-scanning direction. The entire surface of the document table 3 is read by pre-scanning performed before document reading scanning, and the gate is converted into a binary image for black and white reversal.
The image data VDO that has passed through 909 is stored in the shift register 301 as 8
Entered in bit units. When the 8-bit input is completed, the gate circuit 302 checks whether all of the 8-bit data is a white image, and outputs "1" to the signal line 303 if all of the 8-bit data is a white image. That is, after the start of the pre-scan, when the first 8-bit white appears, the F / F 304 is set by the "1" output of the signal line 303. This F / F 304 is reset by VSYNC in advance. Thereafter, it remains in the set state until the next VSYNC comes. When the F / F 304 is set, the latch F / F 305 is loaded with the value of the main scanning counter 351 at that time. This is the fifth
It becomes X ₁ coordinate values in FIG. The value of the sub-scanning counter 350 at that time to latch 306 is loaded, it is Y ₁ coordinate values in Figure 5. Therefore, P ₁ (X ₁ , Y ₁ ) is obtained. Each time "1" is output to the signal 303, the main scanning counter 3
Load the value from 51 into the latch 307. When the value from the main scan counter 351 at the time when the first eight bits of white appear is loaded into the latch 307, the data of the latch 310 (which is set to the maximum value in the X direction at the time of VSYNC) and the comparator The size is compared at 309. If the data of the latch 307 is smaller, the data of the latch 307 is loaded into the latch 310. At this time, the value of the sub-scanning counter 352 is
Loaded at 11. This operation is processed until the next 8 bits enter the shift register 301. If the data of the latches 307 and 310 is applied to the entire image area in this manner, the minimum value in the original area X direction remains in the latch 310, and the Y value at this time remains.
The coordinates of the direction will remain on the latch 311. Since the main scanning counter 351 is a down counter, the coordinates corresponding to the minimum value in the X direction represent the coordinates farthest from the SP in the main scanning direction.
This is P ₃ (X ₃ , Y ₃ ) in FIG. F / F 312 is a flip-flop that is set when the first 8-bit white appears on each main scanning line, is reset by the horizontal synchronizing signal HSYNC, and is set with the first 8-bit white.
Hold until the next HSYNC. When the F / F 312 is set, the value of the main scanning counter corresponding to the position of the first white signal appearing in one line is set in the latch 313. Then, the size is compared by the latch 315 and the comparator 316. A minimum value "0" in the X direction is set in the latch 315 at the time of occurrence of VSYNC. If the data of Ratch 315 is Ratch 3
If the data is less than or equal to 13, the signal 317 becomes active and the data in the latch 313 is loaded into the latch 315. This operation is performed between HSYNC and HSYNC. When the above comparison operation is performed for all image areas, the maximum value of the document coordinates in the X direction, that is, the X coordinate of the white signal at the point closest to the scanning start point in the main scanning direction remains on the latch 315. This is X ₂ in FIG. When the signal line 317 outputs, the value from the sub-scanning counter 352 is loaded into the latch 318. This becomes Y ₂ in FIG. 5 and P ₂ (X ₂ , Y ₂ )
The coordinates are obtained. The latches 319 and 320 are loaded with the value of the main scanning counter 351 and the value of the sub-scanning counter 352 each time 8-bit white appears in the entire image area. Therefore, when the original pre-scanning is completed, the count value at the time when the 8-bit white finally appears remains in the counter. This is the fifth
P ₄ (X ₄ , Y ₄ ) in the figure. The above eight latches (306,311,320,318,305,310,315,
The data line 319) is the bus line B of the CPU unit 308 in FIG.
The data is connected to the US, and the CPU unit 308 reads this data at the end of the prescan. As a result, the CPU unit 308
The coordinate values of the four corners of the original on the upper side can be obtained, whereby the position of the original and the size of the original can be recognized.
Further, the inclination state of the document may be determined. FIG. 5A shows how the coordinates of the four corners P ₁ , P ₂ , P ₃ , and P ₄ of the document placed obliquely on the platen are detected. It is not placed diagonally like this,
As shown in FIG. 5 (b), the document is placed parallel to or against the side of the document table, so that coordinates X2, X3, Y1, and Y4 may be used as information indicating the position and size of the document. FIG. 9 shows a document coordinate detection scan control flow by the CPU unit 308, which will be described below. FIG. 6A shows an example of a document to be read. This document has character information described only in the lower right corner. First, the three control signals shown in FIG. 3 are set to IN = 0, OF = 0, BB = 1.
(ST900), the same value as ST counter 912 and EN counter 913 which are counters for trimming, for example, 0
Set (SP901). In this operation, the image data VDO input to the document position detecting unit shown in FIG. 4 always becomes a black signal. Then, advance of the optical system is started for pre-scanning (SP
902), when reaching the SP position in FIG. 6B (the end of the document table 3: the Y coordinate value corresponds to 0), ST for trimming is performed.
The XMIN equivalent value is set in the counter and the XMAX equivalent value is set in the EN counter (SP905). XMIN and XMAX correspond to the platen glass, that is, the readable main scanning area. Also, by this operation, the VDO signal reflects the image information inside the platen glass as black and white as it is, so the outside of the original on the platen glass is read black by reading the mirror surface of the document holding cover, while The background part without information becomes white, and the information part becomes black. After continuing this control to the right end of the platen, that is, the EP position in FIG. 6B corresponding to the end of the platen (SP906),
Set the same value to both ST and EN counters 912 and 913 again (SP90
8) Set all VDO signals after EP to black. When the optical system reaches the reverse position TP, the optical system is stopped (SP
909, SP910). FIG. 8A shows the state of the read image during this time. The sloping portion is a region outside the trimming that is forcibly made black by BB = 1, and a black portion is a region inside the trimming that is a black portion as read, in which white information is included in both main scanning and sub-scanning directions. The first and last appearing coordinates are DX0, DX1, DY0, DY1, indicating the coordinates of the original sheet. When the optical system reaches the TP, these coordinates are latched on the respective latches of the document position detecting unit shown in FIG. 4 and these coordinate values are set in an area on the RAM of the CPU unit 308. After that (SP911), the process proceeds to the coordinate detection operation of the information portion in the document sheet. First, IN = 1, OF = 0, and BB = 1 are set (SP912), and control is performed so that the VDO signal in the trimming area is inverted between black and white, and the VDO signal outside the trimming area is always black. First, set the ST counter 912 and EN counter 91 so that all VDO signals are black.
The same value is set to 3 (SP913), and the backward movement of the optical system is started (SP914). Then, the right end DY of the original sheet detected by the optical system in the forward movement
When the position reaches 1 (SP915), the reference point DX0 is set to the ST counter 912 in the main scanning direction of the document, and the DX1 far from the reference point is set to the EN counter 913 (SP916).
By this control, the VDO signal in the original is inverted between black and white and black outside the original. This is continued until the left end DY0 of the original, and D
When the value reaches Y0 (SP917), the same value is set again in the ST counter and the EN counter, and all the images are set to black. When reaching HP, stop the optical system (SP920). The state of the VDO signal at the time of this return is shown in FIG. The shaded portion is forcibly made black, and the black portion is the background portion in the document, which is black because of black and white reversal. Then, the information part becomes white. Accordingly, the document position detecting unit shown in FIG.
IX1, IY0, and IY1 are detected as shown in FIG.
Set the area on the 308 RAM (SP921). The HP, SP interval and EP, TP interval shown in FIG. 6 (b) are predetermined distances required to start the optical system at a constant speed by PLL control, and the rising time is known. Also, EP, DY1 interval, DY0, SP
The distance becomes clear when DY0 and DY1 are detected during the forward movement, and the optical system moves at a constant speed between EP and SP, so that the time required for the movement becomes known, and the control described in FIG. It becomes possible. As described above, the position coordinates of the document sheet are detected in the forward movement, and the position coordinates of the information section in the document can be detected using the result. Therefore, from the position information of the information section in the document, the CPU section 308 can know the position of the information section on the document table and the size of the information section. And, based on this location information,
Set the values of ST counter 912 and EN counter 913 described above,
When a document is read, only the information section can be extracted and output, and a noise image generated in an edge portion or the like of the document can be efficiently removed. Also, for example, if the size of the information section is determined based on the position information and the recording material of the printer is selected in this way, the image can be recorded on the recording material suitable for the size of the information section. Further, it is possible to control the image shift amount of the trimming processing unit 306 based on the position information of the information unit, and perform processing such as recording the information unit at an appropriate position (for example, the center) on the recording material of the printer. Also, when the read image data is stored and stored in an electronic file device or the like or transmitted as in a facsimile device, only image information from which useless information such as a blank portion is removed according to the position information of the information section is stored. It can be stored or transmitted, thereby enabling efficient use of the file device and improvement of transmission efficiency. [Effects] As described above, according to the present invention, instead of detecting the position of the information portion in the original document using the entire surface of the original platen on which the original is placed as a detection target area, first, the entire surface of the original platen is detected. A plurality of coordinates corresponding to a plurality of vertices of the document are detected as a detection target area, and a placement position of the document on the platen defined by the detected plurality of coordinates is set as a detection target area, and information in the document is detected. Since a plurality of coordinates corresponding to a plurality of vertices of the portion are detected, for example, it is erroneously recognized that the information portion exists outside the mounting position of the document on the platen if the platen or the document holding plate is dirty. Even if there is a possibility that the document may not be placed on the original platen, a plurality of coordinates corresponding to a plurality of vertices of the information portion in the document are detected using the placement position of the document as the detection target area, Outside position Without erroneous recognition when the information portion exists, the information portion of the document can be reliably detected, thus, it is possible to process the original image properly based on the detection result.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1-1 is an external view of a document reading apparatus, FIG. 1-2 is a block diagram of the document reading apparatus, FIG. 2 is a block circuit diagram of the document reading apparatus, and FIG. Block diagram of memory section, fourth
FIG. 5 is a block diagram relating to a document position detecting unit, FIG. 5 is a diagram showing a state of a document on a platen, FIG.
FIG. 7 is a timing chart of the trimming control, and FIG.
FIG. 9 is a diagram showing a state of an image at the time of coordinate detection. FIG. 9 is a control flow chart. Denotes a CPU unit.

Claims (1)

(57) [Claims] A document table on which a document on which information is recorded is placed; reading means for scanning the document placed on the document table; and an entire surface of the document table as a detection target area, and an output signal from the reading means. First detecting means for detecting a plurality of coordinates corresponding to a plurality of vertices of the document based on the plurality of coordinates, based on the plurality of coordinates detected by the first detecting means, for detecting a mounting position of the document on the document table A second detection unit configured to detect a plurality of coordinates corresponding to a plurality of vertexes of an information portion in the document based on an output signal from the reading unit as a target area; and a plurality of coordinates in the document detected by the second detection unit. Processing means for processing the document image based on a plurality of coordinates corresponding to a plurality of vertices of the information portion.