JP2004357032A - Image reading apparatus, image forming apparatus, image transmission control method, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sequentially transmit image data on an original surface and image data of an original backside read in reading the both sides of the original by one set of transmission lines, to reduce signal lines and to improve original reading productivity. <P>SOLUTION: A transmission timing control part 209 of a reader part U100 outputs an image synchronizing signal with a set of surface image data and backside image data one time. The front surface image data is synchronized with an image synchronizing signal to be outputted, and the backside image data is temporarily stored in an image buffer 210, delayed for a prescribed main scanning synchronizing signal after an output of the surface image data and outputted with the backside image data connected after the surface image data. An image controller part U102 separately divides the connected data into the surface image data and the backside image data according to notified image data length. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus, an image forming apparatus, an image transmission control method, a program, and a storage medium that can simultaneously read both sides of a double-sided document having images on the front and back sides, and particularly to an image from a single-sided document or a double-sided document. The present invention relates to an image reading apparatus, an image forming apparatus, an image transmission control method, a program, and a storage medium that are suitable for application to a digital copying machine that reads and forms an image on a sheet.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a general image forming apparatus such as a digital copying machine is equipped with a double-sided original reading function (a function of reading both sides of an original while transporting the original) in order to improve the original reading performance of the original. Is provided. This type of image forming apparatus is provided with two document reading units, and one of the document reading units reads the front side of the document and the other document reading unit reads the back side of the document. A two-sided document reading apparatus equipped with such a two-sided document flow reading function will be described below.
[0003]
FIG. 11 is a configuration diagram illustrating an example of the internal structure of the duplex document reading apparatus. 11, reference numeral 301 denotes a pickup roller, 302 denotes a separation roller, 303 denotes a registration (hereinafter abbreviated as “registration”) roller, 304 denotes a conveyance roller A, 305 denotes a platen roller, 306 denotes a conveyance roller B, 307 denotes a discharge roller, and 308 denotes a discharge roller. Is a registration sensor, 309 is a read sensor, 310 is a paper ejection sensor, 311 is a first mirror stand, 312 is a second mirror stand, 313 is a lens, 201 is a CCD which is a front side reading sensor of the original, and 202 is a back side reading sensor of the original (Contact image sensor).
[0004]
Next, the operation of the double-sided document reading apparatus will be described. First, the uppermost document among the plurality of documents stacked on the document stacker is separated by the pickup roller 301 and the separation roller 302, and the document is transported to a position corresponding to the registration sensor 308. The document is temporarily stopped by the document detection by the registration sensor 308, and timing is set. Thereafter, the original is sequentially conveyed by the registration roller 303, the conveyance roller A 304, the platen roller 305, the conveyance roller B 306, and the paper discharge roller 307. When the original is detected by the read sensor 309, an image on the surface of the original is read by the CCD 201 after a predetermined time. That is, the original is illuminated by the light source in the first mirror base 311, and the reflected light is incident on the CCD 201 via the first mirror base 311, the second mirror base 312, and the lens 313, and the image of the original surface is scanned by the CCD 201. Read.
[0005]
After a predetermined time from the start of reading the image on the front surface of the document, the CIS 202 reads the image on the back surface of the document. In the CIS 202, a light source and an image sensor are integrated, and the reflected light of the original by the light source is input to the image sensor to read an image on the back surface of the original.
[0006]
FIG. 12 is a block diagram showing an electrical configuration of the duplex document reading apparatus shown in FIG. In FIG. 12, U900 is a reader unit (image reading unit), and U902 is an image controller unit that handles image data sent from the reader unit U900. 912 is a CPU for controlling the reader unit U900, 903 and 906 are analog processors, 904 and 907 are A / D converters, 905 and 908 are shading correction units, 911, 916, 921, and 922 are interfaces (I / F). A circuit 923 is each block (CPU, various memories, encoder, decoder, and the like) of the image controller unit U902.
[0007]
Image data on the front side of the document read by the CCD 201 is subjected to gain adjustment and offset processing by an analog processor 903, and is converted from an analog signal to a digital signal by an A / D converter 904. After that, the digital signal output from the A / D converter 904 is subjected to shading correction by the shading correction unit 905, and then sent to the image controller unit U902 via the I / F circuit 911. The image data on the back side of the document read by the CIS 202 is subjected to gain adjustment and offset processing by an analog processor 906, and is converted from an analog signal to a digital signal by an A / D converter 907. After that, the digital signal output from the A / D converter 907 is subjected to shading correction by the shading correction unit 908, and then sent to the image controller unit U902 via the I / F circuit 916.
[0008]
FIG. 13 is a timing chart of image data transmission between the reader unit U900 and the image controller unit U902. The image synchronization signal A, the main scanning synchronization signal A, the image clock A, and the image data A are various signals and data corresponding to the transmission of the image data read from the front side of the document. The image synchronization signal B, the main scanning synchronization signal B, the image clock B, and the image data B are various signals and data corresponding to the transmission of the image data read from the back side of the document. The image data A on the front side of the document and the image data B on the back side of the document are transmitted by independent transmission lines as shown in FIG.
[0009]
Also, a two-sided document reading apparatus that simultaneously reads both sides of a document with two image sensors, switches image signals corresponding to the read images on both sides of the document output from each image sensor with a selector, and performs time-division image processing. Has been proposed (for example, see Patent Document 1).
[0010]
[Patent Document 1]
JP-A-2000-36890
[0011]
[Problems to be solved by the invention]
However, since the image forming apparatus equipped with the double-sided reading function as described above has independent image data transmission lines corresponding to the read image data on the front side of the document and the read image data on the back side of the document, the reader section and the image The number of signal lines provided between the controller units becomes enormous, and the number of I / F circuits also increases, thereby causing a problem that the circuit configuration becomes complicated and the cost increases. .
[0012]
Further, with the proposal described in Japanese Patent Application Laid-Open No. 2000-36890, the number of I / F circuits can be reduced, but there is a problem that productivity of document reading is reduced due to an increase in image processing time. Was.
[0013]
An object of the present invention is to make it possible to sequentially transmit image data on the front side of a document and image data on the back side of a document in a two-sided reading of a document by a set of transmission lines, thereby reducing the number of signal lines. Another object of the present invention is to provide an image reading apparatus, an image forming apparatus, an image transmission control method, a program, and a storage medium which can improve the productivity of document reading.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image reading apparatus having a flow reading function for reading a document image while transporting the document, wherein when reading both sides of the document by the flow reading function, an image on the surface of the document is read. It is characterized by having control means for controlling the transmission of the image data on both sides of the document by generating the timing signal once by combining the image data on the back side of the document after data transmission.
[0015]
In order to achieve the above object, the present invention provides an image reading apparatus having a flow reading function for reading a document image while transporting the document, wherein when reading both sides of the document by the flow reading function, an image on the surface of the document is read. By combining the image data on the back side of the original after data transmission, image data on both sides of the original are transmitted by one timing signal generation, and the original is transmitted at a transmission clock speed for performing data transmission at the time of double-sided original reading. It is characterized by having control means for controlling transmission of image data of both sides.
[0016]
In order to achieve the above object, the present invention provides an image reading apparatus having a flow reading function for reading a document image while transporting the document, wherein when reading both sides of the document by the flow reading function, an image on the surface of the document is read. By reducing the image data by scaling the data and the image data on the back side of the original, and combining the image data on the back side of the original after the transmission of the image data on the front side of the scaled original, one time It is characterized by having control means for controlling transmission of image data of both sides of a document by signal generation.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
[First Embodiment]
The first embodiment of the present invention is directed to an image forming apparatus that reads both sides of a document using a double-sided document flow reading function that reads both sides of the document while transporting the document. By combining the image data, control is performed to transmit the image data on both sides of the document by one timing signal generation.
[0019]
FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus according to the present embodiment. The image forming apparatus includes a reader unit U100, a printer unit U101, an image controller unit U102, and a document feed control unit U103, and is configured as, for example, a digital copying machine equipped with a double-sided document flow reading function. Further, the image controller unit U102 includes a reader interface 111, a reader memory 112, an encoder 113, a compressed image memory 114, a decoder 115, a page memory 116, a CPU 117, a RAM 118, a ROM 119, a printer interface 120, and an image editing memory 121. I have.
[0020]
More specifically, the image controller unit U102 is connected to the reader unit U100 via the reader interface 111 and to the printer unit U101 via the printer interface 120. In the image controller unit U102, the reader memory 112 is a memory for temporarily storing at least two pages of uncompressed image data of an image read from a document by the reader unit U100. In this case, one page is, for example, one large original (A3 size), and when reading a small original (A4 size), the reader memory 112 is divided and used to continuously print two small originals. It allows reading of images for minutes.
[0021]
In the present image forming apparatus, simultaneous double-sided reading that simultaneously reads both sides of a document is realized. At the time of simultaneous double-sided reading, the image data of the both sides of the document that are read simultaneously are stored in the reader memory 112 by dividing and using the reader memory 112. I try to store. The encoder 113 compresses the image data stored in the reader memory 112. Then, the encoder 113 automatically stores the image data in the compressed image memory 114 in the compressed image memory 114 based on the image data of the original surface on which the reading has been completed. It is possible to determine whether it is image data of the back side.
[0022]
The compressed image memory 114 is a memory for storing image data for a plurality of pages obtained by compression by the encoder 113. The decoder 115 analyzes (expands) the compressed image data stored in the compressed image memory 114 and expands it on the page memory 116. Here, when digital scaling is performed on the image data in the reader memory 112, the image editing memory 121 is used to inflate the image by performing a linear interpolation process or the like at the time of enlargement. A compression unit 113 stores the image data in a compression image memory 114 based on the image data. The ROM 119 is a memory in which a control program is stored. The CPU 117 controls each unit of the image controller unit U102 according to a control program stored in the ROM 119. The RAM 118 is a memory used as a work area of the CPU 117.
[0023]
The document feed control unit U103 controls the operation of a document feeder (hereinafter, referred to as an ADF (Auto Document Feeder)), and performs the control by communicating with the reader unit U100. The reader unit U100 is an image reading unit that reads an image from a document. The printer unit U101 is an image forming unit that forms an image read from a document on paper.
[0024]
Next, the flow of image data in the image forming apparatus will be described with reference to FIG. The image data of the document read by the reader unit U100 is buffered in the reader memory 112 via the reader interface 111, and the image data in the reader memory 112 is further compressed by the encoder 113 and stored in the compressed image memory 114. Is done. When stored in the compressed image memory 114, the image data on the reader memory 112 compressed by the encoder 113 is deleted.
[0025]
In a normal copy operation, the image data in the compressed image memory 114 is analyzed by the decoder 115, expanded on the page memory 116, and output to the printer unit U101 as an image. When the image is normally output to the printer unit U101, the image data in the compressed image memory 114 is deleted.
[0026]
Next, a double-sided document reading operation in the image reading unit (reader unit U100) of the image forming apparatus will be described.
[0027]
FIG. 2 is a block diagram illustrating a configuration of the reader unit U100 and the image controller unit U102 of the image forming apparatus. The reader unit U100 includes a CCD 201, a CIS 202, an analog processor 203, an analog processor 206, an A / D converter 204, an A / D converter 207, a shading correction unit 205, a shading correction unit 208, a transmission timing control unit 209, and an I / F. A circuit 211 and a CPU 212 are provided. The image controller unit U102 includes an I / F circuit 111 (reader interface 111 in FIG. 1) and image processing units 112 to 121 (reader memory 112 to image editing memory 121 in FIG. 1).
[0028]
More specifically, the reader unit U101 reads an image from a document and performs the following processing. The CPU 212 controls each unit of the reader unit U100, and executes the processing shown in the flowchart of FIG. 8 based on a program. The CCD 201 reads image data on the surface of a document. The CIS 202 reads image data on the back side of the document. The analog processors 203 and 206 respectively perform gain adjustment and offset processing on image data on the front surface of the document read by the CCD 201 and image data on the back surface of the document read by the CIS 202. A / D converters 204 and 207 convert analog signals output from analog processors 203 and 206 into digital signals, respectively. The shading correction units 205 and 208 perform shading correction on digital signals output from the A / D converters 204 and 207, respectively.
[0029]
The transmission timing control unit 209 handles the image data output from the shading correction units 205 and 208. That is, the transmission timing control unit 209 generates an image synchronization signal indicating the head of the image data on the front surface of the document (see FIGS. 3A, 5A, and 7A), and is read by the CCD 201. Control to selectively output image data of the original document (image data output from the shading correction unit 205) and image data of the document back surface read by the CIS 202 (image data output from the shading correction unit 208). Do. The image buffer 210 in the transmission timing control unit 209 temporarily stores the image data on the back surface of the document until the transmission of the image data on the front surface of the document is completed. The I / F circuit 211 manages an interface for transmitting image data between the reader unit U100 and the image controller unit U102.
[0030]
The image controller unit U102 handles image data sent from the reader unit U100. The I / F circuit 111 (the reader interface 111 in FIG. 1) manages an interface for transmitting image data between the image controller unit U102 and the reader unit U100. The image processing units 112 to 121 (the reader memory 112 to the image editing memory 121 in FIG. 1) perform respective processes on the image data sent from the reader unit U100 as detailed in FIG.
[0031]
FIG. 3 is a timing chart of image data transmission between the reader unit U100 of the image forming apparatus and the image controller U102. The read image data of the front and back sides of the document is transmitted by the image synchronization signal, the main scanning synchronization signal, and the image synchronization clock. In FIG. 3A, a section indicated by an arrow in the image synchronization signal is a section corresponding to twice the image synchronization signal section at the time of single-sided reading of a document. The image synchronization signal is output once as one set of the front side image data and the back side image data of the document, and the front side image data of the document is combined with the back side image data at the timing shown in FIG.
[0032]
In FIG. 3B, an image synchronization signal section and a section indicated by an arrow in the main scanning synchronization signal correspond to twice the image synchronization signal section and the main scanning synchronization signal section at the time of single-sided reading of a document. It is a section to be performed. The image synchronization signal is output once for each document 1, and the main scanning synchronization signal is output once for each set of front side image data and back side image data for each line. In the present embodiment, the case of data transmission at the timing of FIG. 3A will be described.
[0033]
Next, the flow of image data at the time of reading a two-sided original in the image forming apparatus will be described with reference to the schematic flowchart of FIG.
[0034]
When reading of a two-sided document is set from an operation unit (not shown) of the image forming apparatus, the document is conveyed by the ADF, and the image data on the front surface of the document is read by the CCD 201 of the reader unit U100 at the front surface reading position of the document. (Step S1). The surface image data read by the CCD 201 is subjected to gain adjustment and offset processing by an analog processor 203, and is converted from an analog signal to a digital signal by an A / D converter 204. After that, the digital signal output from the A / D converter 204 is input to the transmission timing control unit 209 after the shading correction is performed by the shading correction unit 205.
[0035]
After a predetermined time has elapsed from the start of reading the image on the front surface of the document, the image data on the back surface of the document is read by the CIS 202 of the reader unit U100 at the reading position on the back surface of the document (step S2). The back side image data read by the CIS 202 is subjected to gain adjustment and offset processing by an analog processor 206, and is converted from an analog signal to a digital signal by an A / D converter 207. After that, the digital signal output from the A / D converter 207 is subjected to shading correction by the shading correction unit 208 and then input to the transmission timing control unit 209.
[0036]
The transmission timing control unit 209 generates an image synchronization signal based on a signal from the read sensor 309 (see FIG. 11), and selects and outputs front side image data and back side image data in synchronization with the image synchronization signal. In the present embodiment, the image synchronization signal is output once as a set of front side image data and back side image data (step S3). The time interval between the image synchronization signals is twice as long as that when reading a single-sided document. The front side image data is output in synchronization with the image synchronization signal, the back side image data is temporarily stored in the image buffer 210 in the transmission timing control unit 209, and is delayed by a predetermined main scanning synchronization signal after the front side image data is output. Then, after the front side image data, the back side image data is connected and output (step S4).
[0037]
The length of the image data is notified to the image controller unit U102 in advance by communication between the CPU 212 of the reader unit U100 and the CPU 117 of the image controller unit U102. The image controller unit U102 divides the transmitted front-side image data and back-side image data according to the image data length notified from the reader unit U100 (step S5), and thereafter treats each of the front and back pages as a page unit.
[0038]
In the present embodiment, the CPU 212 of the reader unit U100 controls the ADF so as to wait for the end of the transmission of the currently transmitted image data and start reading the next original when reading the double-sided original. In other words, control is performed so that the time interval of conveyance for each document is longer than when reading a single-sided document. If reading of a single-sided document is set instead of a double-sided document, reading of the document and transmission of image data are performed without leaving a time interval for transporting the document.
[0039]
As described above, according to the present embodiment, in the image forming apparatus, when reading both sides of a document by the double-sided document flow reading function, the image data on the back surface of the document is combined after the image data on the front surface of the document is transmitted. Since image data on both sides of the document is controlled by one timing signal generation, the image data on the front surface of the document and the image data on the back surface of the document are sequentially transmitted by a pair of transmission lines in both-side reading of the document. And the number of signal lines can be reduced.
[0040]
[Second embodiment]
According to the second embodiment of the present invention, in the image forming apparatus, when reading both sides of a document using the double-sided document flow reading function, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted. The image data on both sides of the original is transmitted by generating the timing signal described above, and the image data on both sides of the original is transmitted at a transmission clock speed for performing data transmission when reading a two-sided original.
[0041]
Next, a double-sided document reading operation of the image reading unit (leader unit) of the image forming apparatus according to the present embodiment will be described. Note that in the present embodiment, the description overlapping with the first embodiment is omitted, and the configuration and operation unique to the present embodiment will be described. In the present embodiment, a first transmission clock speed for transmitting image data when reading one side of a document and a second transmission clock speed for transmitting image data when reading both sides of a document are provided. At the time of reading, image data is transmitted at a transmission clock of the second transmission clock speed. As a result, even when reading both sides of a document, it is not necessary to provide a time interval for transporting each document, and the document reading productivity can be improved.
[0042]
FIG. 4 is a block diagram illustrating a configuration of the reader unit U100 and the image controller unit U102 of the image forming apparatus according to the present embodiment. The reader unit U100 includes a CCD 201, a CIS 202, an analog processor 203, an analog processor 206, an A / D converter 204, an A / D converter 207, a shading correction unit 205, a shading correction unit 208, a transmission timing control unit 209, and an I / F. The circuit includes a circuit 211, a CPU 212, a clock generator 213 (first transmission clock speed), and a clock generator 214 (second transmission clock speed). The image controller unit U102 includes an I / F circuit 111 (reader interface 111 in FIG. 1) and image processing units 112 to 121 (reader memory 112 to image editing memory 121 in FIG. 1).
[0043]
Explaining the characteristic configuration of the present embodiment, the CPU 212 controls each unit of the reader unit U100, and executes the processing shown in the flowchart of FIG. 9 based on a program. The transmission timing control unit 209 includes image buffers 210 and 215. The image buffers 210 and 215 are buffers for converting the transmission speed of image data and for temporarily storing image data. In this case, the front side image data of the document is temporarily stored in the image buffer 215, and the back side image data of the document is temporarily stored in the image buffer 210. The clock generator 213 generates a transmission clock for transmitting image data when reading one side of a document. The clock generator 214 generates a transmission clock for transmitting image data when reading both sides of a document. In order to transmit the image data for the double-sided original in the image data transmission time for the single-sided original, the transmission clock at the time of double-sided reading is twice or more the frequency of the transmission clock at the time of single-sided reading.
[0044]
The CPU 212 selects a transmission clock generated from the clock generator 213 when reading a document on one side, and selects a transmission clock generated from the clock generator 214 when reading both sides of a document, and transmits image data using each transmission clock. The other configuration is the same as that of the first embodiment, and the description is omitted.
[0045]
FIG. 5 is a timing chart of image data transmission between the reader unit U100 of the image forming apparatus and the image controller U102. The read image data of the front and back sides of the document is transmitted by the image synchronization signal, the main scanning synchronization signal, and the image synchronization clock. In FIG. 5A, a clock for transmitting double-sided image data is selected at the time of reading a double-sided original, so that the main scanning synchronization signal, the image synchronization clock, and the image data have twice the frequency of reading a single-sided original. Since the section indicated by the arrow in the image synchronization signal is the same as the image synchronization signal at the time of single-sided reading of the document, the number of main scanning synchronization signals, image synchronization clocks, and image data is twice that at the time of single-sided document reading. The image synchronization signal is output once as a set of front side image data and back side image data of the document, and the front side image data of the document is combined with the back side image data at the timing shown in FIG.
[0046]
In FIG. 5B, an image synchronization signal section and a section indicated by an arrow in the main scanning synchronization signal are the same as the image synchronization signal section at the time of single-sided reading of a document and the main scanning synchronization signal. Since the clock for double-sided image data transmission is selected, the frequency of the image synchronization clock and the image data are twice as high as those for reading a single-sided original. The image synchronization signal is output once for each document 1, and the main scanning synchronization signal is output once for each set of front side image data and back side image data for each line. In the present embodiment, a case of data transmission at the timing of FIG. 5A will be described.
[0047]
Next, the flow of image data at the time of reading a double-sided original in the image forming apparatus will be described with reference to the schematic flowchart of FIG.
[0048]
When reading of a two-sided document is designated from the operation unit (not shown) of the image forming apparatus, the CPU 212 of the reader unit U100 selects the transmission clock of the clock generator 214 for reading the two-sided document. The document is conveyed by the ADF, and the image data on the front surface of the document is read by the CCD 201 at the front surface reading position of the document (step S11). The surface image data read by the CCD 201 is subjected to gain adjustment and offset processing by an analog processor 203, and is converted from an analog signal to a digital signal by an A / D converter 204. After that, the digital signal output from the A / D converter 204 is input to the transmission timing control unit 209 after the shading correction is performed by the shading correction unit 205.
[0049]
After a predetermined time has elapsed from the start of image reading on the front side of the document, the image data on the back side of the document is read by the CIS 202 of the reader unit U100 at the back side reading position of the document (step S12). The surface image data read by the CIS 202 is subjected to gain adjustment and offset processing by an analog processor 206, and is converted from an analog signal to a digital signal by an A / D converter 207. After that, the digital signal output from the A / D converter 207 is subjected to shading correction by the shading correction unit 208 and then input to the transmission timing control unit 209.
[0050]
The transmission timing control unit 209 generates an image synchronization signal based on a signal from the read sensor 309, and selects and outputs front side image data and back side image data in synchronization with the image synchronization signal. In the present embodiment, the image synchronization signal is output once as a set of front side image data and back side image data (step S13). The surface image data is temporarily stored in the image buffer 215 in the transmission timing control unit 209, and is read (output) at the frequency of the transmission clock of the clock generation unit 214 in synchronization with the image synchronization signal. The back side image data is temporarily stored in the image buffer 210 in the transmission timing control unit 209, and after the front side image data is output, the frequency of the transmission clock of the clock generation unit 214 is synchronized with the image synchronization signal for the back side image data. Is read (output) (step S14).
[0051]
The image data output from the transmission timing control unit 209 of the reader unit U100 is transmitted to the image controller unit U102 via the I / F circuit 211 of the reader unit U100 and the I / F circuit 111 of the image controller unit U102. The image controller unit U102 handles image data transmitted from the reader unit U100. The transmission clock speed is notified to the image controller unit U102 in advance by communication between the CPU 212 of the reader unit U100 and the CPU 117 of the image controller unit U102. The image controller unit U102 divides the transmitted front-side image data and back-side image data according to the transmission clock speed notified from the reader unit U100 (step S15), and thereafter handles them as page units for each of the front and back sides.
[0052]
In the present embodiment, the clock generation unit 213 for generating the transmission clock 1 and the clock generation unit 214 for generating the transmission clock 2 are separately provided, but the PLL (transmission clock 1) is used by using one transmission clock (transmission clock 1). The transmission clock 2 may be generated by multiplying by a phase lock loop (Phase Lock Loop) circuit or the like, and the transmission clock 1 or the transmission clock 2 may be selected and used depending on whether single-side reading or double-side reading is performed.
[0053]
As described above, according to the present embodiment, in the image forming apparatus, when reading both sides of a document by the double-sided document flow reading function, the image data on the back surface of the document is combined after the image data on the front surface of the document is transmitted. Since the image data of both sides of the original is transmitted by one timing signal generation, and the transmission of the image data of both sides of the original is controlled by the transmission clock for performing the data transmission at the time of reading the two-sided original, both sides of the original are read. It is possible to sequentially transmit the image data of the front side of the original and the image data of the back side of the original through a pair of transmission lines, thereby reducing the number of signal lines and also when reading both sides of the original. There is no need to provide a time interval for document conveyance, and the productivity of document reading can be improved.
[0054]
[Third Embodiment]
According to the third embodiment of the present invention, in the image forming apparatus, when reading both sides of a document by the double-sided document flow reading function, image data on the front surface of the document and image data on the back surface of the document are reduced to reduce the image data. At the same time, after transmitting the image data on the front side of the scaled original, the image data on the rear side of the scaled original is combined to control transmission of the image data on both sides of the original by generating a timing signal once. .
[0055]
Next, a double-sided document reading operation of the image reading unit (leader unit) of the image forming apparatus according to the present embodiment will be described. In the present embodiment, the description overlapping with the first and second embodiments will be omitted, and the configuration and operation unique to the present embodiment will be described. In the present embodiment, a scaling unit for scaling and reducing the image data is provided, and the image data is reduced and transmitted when reading both sides of the document.
[0056]
The scaling process referred to here means thinning out image data in the main scanning direction for each pixel, thinning out image data in the sub-scanning direction for each line, or two pixels for image data in the main scanning direction. Control of converting image data of one line into image data of one pixel by averaging, or converting image data of two lines into image data of one line by averaging with respect to image data in the sub-scanning direction, The processing is to reduce image data. In the present embodiment, description will be made using a method of converting image data of two lines into image data of one line by averaging the image data in the sub-scanning direction.
[0057]
As a result, even when reading both sides of a document, it is not necessary to provide a time interval for transporting each document, thereby improving the productivity of document reading.
[0058]
FIG. 6 is a block diagram illustrating a configuration of the reader unit U100 and the image controller unit U102 of the image forming apparatus according to the present embodiment. The reader unit U100 includes a CCD 201, a CIS 202, an analog processor 203, an analog processor 206, an A / D converter 204, an A / D converter 207, a shading correction unit 205, a shading correction unit 208, a transmission timing control unit 209, and an I / F. A circuit 211 and a CPU 212 are provided. The image controller unit U102 includes an I / F circuit 111 (reader interface 111 in FIG. 1) and image processing units 112 to 121 (reader memory 112 to image editing memory 121 in FIG. 1).
[0059]
Explaining the characteristic configuration of the present embodiment, the CPU 212 controls each unit of the reader unit U100, and executes the processing shown in the flowchart of FIG. 10 based on a program. The transmission timing control unit 209 includes image buffers 210 and 215. The image buffers 210 and 215 are buffers for temporarily storing image data and for thinning out images at the time of reading. In this case, the front side image data of the document is temporarily stored in the image buffer 215, and the back side image data of the document is temporarily stored in the image buffer 210.
[0060]
Regarding the reading of image data from the image buffers 210 and 215, the CPU 212 reads all the image data stored in the image buffer 210 or 215 when reading one side of the document, and reads the image data stored in the image buffers 210 and 215 when reading both sides of the document. With respect to the data, a setting is made such that image data of two pixels is converted into image data of one pixel by averaging with respect to image data in the main scanning direction and read out. In this embodiment, if the reading resolution of the image data is 600 dpi in the main scanning direction and 600 dpi in the sub-scanning direction when reading a single-sided original, the image data is scaled to 300 dpi in the main scanning direction when reading a double-sided original. Will be output. The other configuration is the same as that of the first embodiment, and the description is omitted.
[0061]
FIG. 7 is a timing chart of image data transmission between the reader unit U100 and the image controller unit U102 of the image forming apparatus. The read image data of the front and back sides of the document is transmitted by the image synchronization signal, the main scanning synchronization signal, and the image synchronization clock. In FIG. 7A, a section indicated by an arrow in the image synchronization signal is the same section as the image synchronization signal at the time of single-sided reading of the document, and the main scanning synchronization signal and the image synchronization clock are the same as at the time of single-sided reading. The image synchronization signal is output once as one set of the front side image data and the back side image data of the document, and the front side image data of the document is combined with the back side image data and transmitted at the timing shown in FIG. The image data is reduced by converting the front side image data and the back side image data into image data of one pixel by adding and averaging the image data of two pixels in the main scanning direction, and converting the front side image data with respect to one image synchronization signal. After transmission, the back side image data is combined and output.
[0062]
In FIG. 7B, an image synchronization signal section and a section indicated by an arrow in the main scanning synchronization signal are the same as an image synchronization signal section and a main scanning synchronization signal section when a single side of a document is read. The image synchronization signal is output once for each document 1, and the main scanning synchronization signal is output once for each set of front side image data and back side image data for each line. The image data is reduced by converting the front side image data and the back side image data into image data of one pixel by adding and averaging the image data of two pixels in the main scanning direction, and reducing the front side image data by one main scanning synchronization signal. Is transmitted and the back side image data is combined and output. At the timing shown in FIG. 7B, the front side image data and the back side image data are combined and transmitted. In the present embodiment, a case of data transmission at the timing of FIG. 7A will be described.
[0063]
Next, the flow of image data at the time of reading a double-sided original in the image forming apparatus will be described with reference to the schematic flowchart of FIG.
[0064]
When reading of a two-sided document is designated from an operation unit (not shown) of the image forming apparatus, the CPU 212 of the reader unit U100 thins out and outputs the read image data from the image buffers 210 and 215 of the transmission timing control unit 209. Set. The document is conveyed by the ADF, and the image data on the front surface of the document is read by the CCD 201 at the front surface reading position of the document (step S21). The surface image data read by the CCD 201 is subjected to gain adjustment and offset processing by an analog processor 203, and is converted from an analog signal to a digital signal by an A / D converter 204. After that, the digital signal output from the A / D converter 204 is input to the transmission timing control unit 209 after the shading correction is performed by the shading correction unit 205.
[0065]
After a predetermined period of time has elapsed since the reading of the image on the front side of the document has started, image data on the back side of the document is read by the CIS 202 of the reader unit U100 at the back side reading position of the document (step S22). The surface image data read by the CIS 202 is subjected to gain adjustment and offset processing by an analog processor 206, and is converted from an analog signal to a digital signal by an A / D converter 207. After that, the digital signal output from the A / D converter 207 is subjected to shading correction by the shading correction unit 208 and then input to the transmission timing control unit 209.
[0066]
The transmission timing control unit 209 generates an image synchronization signal based on a signal from the read sensor 309, and selects and outputs front side image data and back side image data in synchronization with the image synchronization signal. In the present embodiment, the image synchronization signal is output once as one set of front side image data and back side image data (step S23). The surface image data is temporarily stored in the image buffer 215, and the image data of two pixels in the main scanning direction is converted to image data of one pixel by averaging and output. The back side image data is temporarily stored in the image buffer 210, and after the front side image data is output, the image data of two pixels in the main scanning direction is converted into one pixel image data by averaging and output (step S24). .
[0067]
The magnification process is notified to the image controller unit U102 in advance by communication between the CPU 212 of the reader unit U100 and the CPU 117 of the image controller unit U102. In accordance with the scaling process notified from the reader unit U100, the image controller unit U102 separates the transmitted front-side image data and back-side image data, and returns to the original image data corresponding to the magnification in the main scanning direction (step S25). ), And thereafter, each page is treated as a page unit.
[0068]
In this embodiment, the configuration in which the resolution of the image data in the main scanning direction is changed from 600 dpi to 300 dpi to reduce the image data when reading the double-sided document has been described, but the present invention is not limited to this. When combining for each of the front and back image synchronization signals, scaling may be performed in the sub-scanning direction. In that case, instead of the scaling method using an image memory described above (digital scaling), A variable power method (scan variable power) for changing the document conveyance speed may be used. In this case, since the magnification is changed according to the document conveying speed, the magnification changing means is not required. When reading a document on one side, the image data may be passed through the image buffer without being temporarily stored in the image buffer.
[0069]
As described above, according to the present embodiment, in the image forming apparatus, when reading both sides of a document by the flow reading function, image data on the front surface of the document and image data on the back surface of the document are reduced in size to reduce the image data. At the same time, the image data on the back side of the original is combined with the image data on the back side of the original after transmission of the image data on the front side of the scaled original, so that control of transmitting the image data on both sides of the original by one timing signal generation is performed. Therefore, it is possible to sequentially transmit the image data of the front surface of the document and the image data of the back surface of the document in the two-sided reading of the document through a set of transmission lines, and it is possible to reduce the number of signal lines and to reduce the number of signal lines. It is not necessary to provide a time interval for document conveyance even during double-sided reading, thereby improving document reading productivity.
[0070]
[Other embodiments]
In the above embodiment, an image forming apparatus (copier) equipped with the image reading apparatus of the present invention has been described as an example. However, the present invention is not limited to this, and an image forming apparatus equipped with the image reading apparatus is provided. The present invention can also be applied to a (multifunction peripheral) or an image reading apparatus alone.
[0071]
In the above embodiment, the image forming method of the image forming apparatus is not limited to a specific image forming method, but can be applied to any image forming method such as an electrophotographic method or an inkjet method.
[0072]
Another object of the present invention is to provide a storage medium storing program codes of software for realizing the functions of the embodiments to a system or an apparatus, and a computer (or a CPU or an MPU or the like) of the system or apparatus to store the storage medium. It is also achieved by reading and executing the program code stored in the.
[0073]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0074]
Examples of a storage medium for supplying the program code include a floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, and DVD. -RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, and the like can be used.
[0075]
When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. This also includes a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0076]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This also includes the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0077]
【The invention's effect】
As described above in detail, according to the present invention, when reading both sides of an original by the flow reading function, one time of timing signal generation by combining image data of the original backside after transmission of image data of the original front side Image data on both sides of the original is transmitted, so that the image data on the front side of the original and the image data on the back side of the original can be sequentially transmitted by a pair of transmission lines in both-side scanning of the original, reducing the number of signal lines It is possible to do.
[0078]
Further, according to the present invention, when reading both sides of a document by the flow reading function, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted, so that the image data on both sides of the document are generated by one timing signal generation. , And image data of both sides of the original are transmitted at a transmission clock speed for performing data transmission when reading a two-sided original. Transmission can be performed sequentially through a set of transmission lines, so that the number of signal lines can be reduced.Also, there is no need to provide a time interval for document conveyance when reading both sides of a document. It is possible to improve productivity.
[0079]
Further, according to the present invention, when reading both sides of a document by the flow reading function, the image data on the front surface of the document and the image data on the back surface of the document are scaled to reduce the image data, and the image of the scaled document surface is reduced. By combining the image data on the back side of the original after the data transmission, the image data on both sides of the original can be transmitted by one timing signal generation, so that the number of signal lines can be reduced in the same manner as described above. At the same time, it is possible to improve the productivity of document reading.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration example of a reader unit and an image controller unit of the image forming apparatus of FIG. 1;
3A and 3B are timing charts of image data transmission between a reader unit and an image controller unit in FIG. 2; FIG. 3A shows a case where data is combined for each image synchronization signal; FIG. This is the case when data is combined with the data.
FIG. 4 is a block diagram illustrating a configuration example of a reader unit and an image controller unit of an image forming apparatus according to a second embodiment of the present invention.
5A and 5B are timing charts of image data transmission between a reader unit and an image controller unit in FIG. 4; FIG. 5A shows a case where data is combined for each image synchronization signal, and FIG. This is the case when data is combined with the data.
FIG. 6 is a block diagram illustrating a configuration example of a reader unit and an image controller unit of an image forming apparatus according to a third embodiment of the present invention.
7A and 7B are timing charts of image data transmission between the reader unit and the image controller unit of FIG. 6, where FIG. 7A shows a case where data is combined for each image synchronization signal, and FIG. This is the case when data is combined with the data.
FIG. 8 is a flowchart showing a duplex document reading process in the configuration of FIG. 2;
FIG. 9 is a flowchart showing a duplex document reading process in the configuration of FIG. 4;
FIG. 10 is a flowchart showing a duplex document reading process in the configuration of FIG. 6;
FIG. 11 is a configuration diagram showing an internal structure of a document reading apparatus (reader unit) according to a conventional example.
FIG. 12 is a block diagram illustrating a configuration example of a reader unit and an image controller unit of FIG. 11;
13 is a timing chart of image data transmission between the reader unit and the image controller unit in FIG.
[Explanation of symbols]
U100 leader section
U101 Printer section
U102 Image controller
U103 Document feed control unit
201 CCD (first document reading means)
202 CIS (second original reading means)
209 Transmission timing control unit (control means, timing control means)
210 Image buffer (image storage means, first image storage means)
211 I / F circuit
212 CPU (control means, clock switching means)
213 Clock generator
214 clock generator
215 Image buffer (second image storage unit)

Claims (26)

An image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the flow reading function, control for transmitting image data on both sides of the document by generating a timing signal once by combining image data on the back surface of the document after transmitting image data on the front surface of the document. An image reading apparatus comprising: First document reading means for reading the front side of the document, second document reading means for reading the back side of the document, generating the timing signal indicating the head of image data on the front side of the document, and reading the first document; 2. The image reading apparatus according to claim 1, further comprising: timing control means for selectively outputting image data on the front side of the document from the means and image data on the back side of the document from the second document reading means. 3. The image reading apparatus according to claim 2, wherein the timing control unit includes an image storage unit that temporarily stores the image data on the back surface of the document until the transmission of the image data on the front surface of the document is completed. 2. The image reading apparatus according to claim 1, wherein the image reading apparatus does not perform an operation of reading a next document until transmission of image data is completed. An image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the flow reading function, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted, so that the image data on both sides of the document are transmitted by one timing signal generation, and both sides are transmitted. An image reading apparatus, comprising: control means for controlling transmission of image data on both sides of a document at a transmission clock speed for data transmission when reading a document. First document reading means for reading the front side of the document, second document reading means for reading the back side of the document, generating the timing signal indicating the head of image data on the front side of the document, and reading the first document; Means for selectively outputting image data on the front side of the original from the means and image data on the back side of the original from the second original reading means, and a first clock speed for performing data transmission when reading a single-sided original 6. The image reading apparatus according to claim 5, further comprising: clock switching means for switching a second clock speed for performing data transmission when reading the double-sided document. 2. The image processing apparatus according to claim 1, wherein the timing control unit includes a first image storage unit that temporarily stores the image data of the front surface of the document and a second image storage unit that temporarily stores the image data of the back surface of the document. 7. The image reading device according to 6. The control means controls the clock switching means to transmit the image data from the first or second document reading means at the first clock speed at the time of reading the one-sided document, and at the time of reading the two-sided document at the time of reading the one-sided document. 7. The image reading apparatus according to claim 5, wherein the image data from the first and second document reading units is transmitted at the second clock speed. 7. The image reading apparatus according to claim 6, wherein the second clock speed is at least twice as fast as the first clock speed. An image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the drift reading function, the image data on the front surface of the document and the image data on the back surface of the document are reduced in size to reduce the image data, and after the transmission of the scaled document image data on the front surface, the scaling is performed. An image reading apparatus comprising control means for controlling the transmission of image data on both sides of a document by one timing signal generation by combining the image data on the back side of the document. First document reading means for reading the front side of the document, second document reading means for reading the back side of the document, generating the timing signal indicating the head of image data on the front side of the document, and reading the first document; 11. The image reading apparatus according to claim 10, further comprising timing control means for selectively outputting image data on the front side of the document from the means and image data on the back side of the document from the second document reading means. 2. The image processing apparatus according to claim 1, wherein the timing control unit includes a first image storage unit that temporarily stores the image data of the front surface of the document and a second image storage unit that temporarily stores the image data of the back surface of the document. 12. The image reading device according to item 11. 11. The image reading apparatus according to claim 10, wherein the scaling control by the control unit is control for thinning out image data in the main scanning direction for each pixel. 11. The image reading apparatus according to claim 10, wherein the scaling control by the control unit is control for thinning out image data in the sub-scanning direction line by line. 11. The image according to claim 10, wherein the scaling control by the control means is control for converting image data of two pixels into image data of one pixel by averaging the image data in the main scanning direction. Reader. 11. The image according to claim 10, wherein the scaling control by the control unit is control for converting image data of two lines into image data of one line by averaging the image data in the sub-scanning direction. Reader. An image forming apparatus comprising the image reading device according to claim 1. An image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting a document,
When reading both sides of a document by the flow reading function, the image data on the back side of the document is combined with the image data on the back side of the document after the image data on the front side of the document is transmitted, so that the image data on both sides of the document are transmitted by one timing signal generation. Image transmission control method. An image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting a document,
When reading both sides of a document by the flow reading function, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted, so that the image data on both sides of the document are transmitted by one timing signal generation, and both sides are transmitted. An image transmission control method, wherein the image data on both sides of the original is transmitted at a transmission clock speed for performing data transmission when reading the original. An image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting a document,
When reading both sides of a document by the drift reading function, the image data on the front surface of the document and the image data on the back surface of the document are reduced in size to reduce the image data, and after the transmission of the scaled document image data on the front surface, the scaling is performed. An image transmission control method, characterized in that image data on both sides of a document is transmitted by one timing signal generation by combining the image data on the back side of the document. When reading both sides of a document using the flow reading function, which reads the document image while transporting the document, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted. A program that allows a computer to realize the function of transmitting data. When reading both sides of a document using the flow reading function, which reads the document image while transporting the document, the image data on the back side of the document is combined after the image data on the front side of the document is transmitted. A program for causing a computer to realize a function of transmitting data and transmitting image data of both sides of a document at a transmission clock speed for transmitting data when reading a two-sided document. When reading both sides of a document by the flow reading function of reading a document image while transporting the document, the image data on the front surface of the document and the image data on the back surface of the document are reduced in size and the image data is reduced, and A program for causing a computer to realize a function of transmitting image data on both sides of an original by generating timing signals once by combining the image data on the back side of the original after the transmission of the image data. A computer-readable storage medium storing a program for executing an image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the flow reading function, the program transmits image data on both sides of the document by generating a timing signal once by combining image data on the back surface of the document after transmitting image data on the front surface of the document. A storage medium comprising a module. A computer-readable storage medium storing a program for executing an image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the flow reading function, the program transmits image data on both sides of the document by generating a timing signal once by combining image data on the back surface of the document after transmitting image data on the front surface of the document. And a module for transmitting image data on both sides of the original at a transmission clock speed for transmitting data when reading a two-sided original. A computer-readable storage medium storing a program for executing an image transmission control method in an image reading apparatus having a flow reading function of reading a document image while transporting the document,
When reading both sides of a document by the flow reading function, the program reduces the image data by scaling the image data on the front surface of the document and the image data on the back surface of the document, and transmits the image data on the front surface of the scaled document. A storage medium having a module for transmitting image data on both sides of a document by generating a timing signal once by combining the image data on the back side of the document after scaling.

Images