JP3163735B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading an image on a document and outputting an image signal.

[0002]

2. Description of the Related Art Conventionally, an image reading apparatus has been used as an input section of a digital copying machine or a facsimile. In these image reading apparatuses, two image sensors are used to read a two-sided document having images on both sides of the document in one pass.

By using two image sensors, the front and back sides of a document can be read independently. However, providing two systems of processing units for image signals output from each image sensor significantly increases the cost. Therefore, only one processing unit is provided and image signals from each image sensor are processed at different timings. Section.

For example, in an image reading apparatus disclosed in Japanese Patent Application Laid-Open No. 3-3564, two image sensors are arranged so as to sandwich a document and are substantially at the same position with respect to the direction in which the document is transported. Is temporarily stored in the page memory, and after the output of the image signal from the other image sensor is completed, the image signal is read out from the page memory and output.

In Japanese Patent Application Laid-Open No. 3-265355, two image sensors are fixedly arranged at a distance corresponding to the maximum document length in the document conveyance direction, and output from each image sensor. 1 shows an image reading apparatus which sequentially outputs image signals as it is.

[0006]

However, in the former device described above, a page memory for temporarily storing an image signal is required, and a circuit for controlling reading and writing to the page memory is also required. This is a factor that increases the cost of the image reading device.

In the latter apparatus, there is no inconvenience when reading the original of the maximum size. However, when reading an original of a smaller size, the reading of the first side is completed after the reading of the first side is completed. There is a problem that a waiting time is required until the reading of the original is started, and it takes time to read the double-sided document.

In view of the above problems, the present invention does not require a page memory for temporarily storing an image signal output from an image sensor, and can always read an original of various sizes in the shortest time. It is intended to provide a reader.

[0009]

Means for Solving the Problems The apparatus according to the invention of claim 1, in order to solve the problems described above, original convey means for conveying the original, a detecting means for detecting the length of the document, first
In the first reading position, the first
A first reading means for reading an image of the surface, the first reading
Is located on the downstream side of the
2 at the reading position, the second
Second reading means for reading an image of the surface, the second reading
Moving the means from the standby position to the second reading position
A driving means, since the detection end by said detecting means, based on its detection result, the second reading means, said first
The second reading position separated many predetermined length than the length of the document from the reading means, the leading end of the original is the second
Of so as to move faster than moved to the reading position, before
And control means for controlling the driving means .

[0010]

The length of the original (original length) is detected by the detecting means. The document is conveyed by the document conveying means. During the conveyance, the first surface is read by the first reading means, and then the second surface is read by the second reading means.

The second reading means is driven by the driving means.
Is it is movable in the conveying direction of the document, based on the detection result by the detection means, the length of the document from the first reading means
Move to the second reading position separated by a corresponding amount ,
It is controlled by control means.

That is, the second reading position corresponds to the first reading position.
It is separated from the reading means by a predetermined length more than the length of the original.
Position. The second reading position is a position as close as possible to the first reading unit in consideration of the moving speed and positioning accuracy of the second reading unit with respect to the length of the document.

[0013]

FIG. 1 is a sectional front view showing the entire structure of a copying machine 1 according to the present invention, and FIG. 2 is a front view of an operation panel OP.

In these figures, a copying machine 1 has a scanning system 10 for reading an original and converting it into an image signal.
An image signal processing unit 20 for processing an image signal sent from
A memory unit 30 for switching image data input from the image signal processing unit 20 to a printer device as it is or to store the image data in a memory, and the like based on the image data input from the memory unit 30;
Processing unit 4 for driving two semiconductor lasers 61 and 62
0, an optical system 60 for guiding the two laser beams from the semiconductor lasers 61 and 62 to different exposure positions on the photosensitive drum 71, and developing and transferring and fixing the latent image formed by the exposure on paper. An image forming system 70 for forming an image, an operation panel OP provided on the upper surface of the main body, a document transport section 500 for transporting a document and reversing the front and back as necessary, and for feeding a sheet to a transfer position again Of paper re-feeding section 600 of FIG.

The scanning system 10 and the image signal processing unit 20
The reading device IR is also provided by the print processing unit 40,
The printer device PRT is constituted by the optical system 60, the image forming system 70, and the like.

The scanning system 10 includes original reading units 10a and 10b for exclusively reading the front and back surfaces of the original, respectively. Document reading sections 10a, 1
Reference numeral 0b includes an exposure lamp 11a for illuminating the original, a lamp guide 11b, a selfoc lens array 14a, and a photoelectric conversion element 16 or 17 composed of a contact type CCD image sensor.

The original reading section 10a is for reading the surface of the original, and can scan below the original glass 18. The other document reading section 10b
Is for reading the back surface of the document, and is fixedly disposed immediately after the registration roller 505 in the document transport section 500a.

The image signal processing section 20 includes the photoelectric conversion element 1
The image signals output from the image processing units 6 and 17 are processed to identify each pixel of the original image as a specific color (second color) and another color (first color). Output attached image data. The memory unit 30 will be described later in detail.

The print processing unit 40 sorts the image data with the color data sent thereto into the two semiconductor lasers 61 and 62, and determines the difference between the exposure positions corresponding to the two semiconductor lasers 61 and 62. Accordingly, the image data given to one semiconductor laser 62 is delayed.

The optical system 60 includes semiconductor lasers 61 and 62,
Dichroic mirror 63 for combining two laser beams, polygon mirror 65 for deflecting the combined laser beam, main lens 69, reflection mirror 67a, dichroic mirror for separating the combined laser beam into the original two laser beams 68, reflecting mirrors 67b, 67c and the like.

The image forming system 70 includes a development transfer system 70A, a transport system 70B, and a fixing system 70C. The development transfer system 70A includes a photosensitive drum 71 that is driven to rotate in a counterclockwise direction in FIG. 1, a first charging charger 72a disposed around the photosensitive drum 71 in order from the upstream side in the rotation direction, and a first developing device 7
3a, a second charging charger 72b, a second developing unit 73b,
It comprises a transfer charger 74, a separation charger 75, a cleaning unit 76 and the like.

The first developing unit 73a contains a two-component developer composed of a red toner and a carrier corresponding to a second color, and the second developing unit 73b stores a black toner and a carrier corresponding to the first color. Is stored.

The transport system 70B is loaded from cassettes 80a and 80b for storing paper, size detection sensors SE11 and SE12 for detecting the paper size, a paper guide 81, a timing roller 82, a transport belt 83, and a re-feed unit 600. And horizontal transport rollers 86a-86c for transporting the fed sheets.

The fixing system 70C includes fixing rollers 84 and 84 for conveying the paper while thermocompressing the paper, a discharge roller 85, and a discharge sensor SE62 for detecting discharge of the paper.
The re-feeding unit 600 temporarily stores the sheet discharged from the discharge roller 85, and in the case of the double-side mode, reverses the front and back,
In the combining mode, the recirculation type is a type in which the sheet is fed into the horizontal transport roller 86a of the transport system 70B for image formation (printing) again without performing the reverse. Refeed unit 60
Reference numeral 0 includes a switching claw 601 for switching between discharge to the discharge tray 621 and re-feeding, a transport roller 602, a reversing roller 603, a reversing sensor SE61, and the like.

In the double-sided mode, the left end of the switching claw 601 is moved upward by a solenoid (not shown).
As a result, the sheet discharged from the discharge roller 85 is guided toward the transport roller 602 and reaches the reversing roller 603 through the transport roller 602.

When the rear end of the sheet reaches the reversing sensor SE61, the reversing roller 603 is reversed, whereby the sheet is conveyed toward the horizontal conveying roller 86a, and passes through the horizontal conveying rollers 86b and 86c to the timing roller 82. Reach and wait. At this time, the next sheet is also sequentially conveyed at a predetermined interval, and the number of sheets that can be copied on one side of the sheet depends on the length of the sheet if there is no delay in image data. Become.

The document feeder 500 includes a document feed tray 51
The document set on top of document 0 is automatically conveyed onto document glass 18, and after the document is read by document reading unit 10a, the document is discharged to document discharge unit 511.

The document feeder 500 includes a paper feed roller 501,
Separating roller 502, separating pad 503, intermediate roller 50
4, registration roller 505, transport belt 506, reversing roller 507, switching claw 508, discharge roller 509, paper feed tray 510, paper discharge tray 511, document scale 51
2, a paper feed sensor 513, a discharge sensor 514, and the like.

The operation of the document transport section 500 differs depending on the document reading mode. The document reading mode includes a scan mode in which the document is read by the scanning operation of the document reading unit 10a, and a panning mode in which the document is transported while the document reading unit 10a is stopped.

Therefore, the operation of the document conveying unit 500 depends on whether only one side of the document is read or both sides are read.
), A panning single-sided mode, and a panning double-sided mode.

In the one-sided mode, one or a plurality of originals are set on the paper feed tray 510 with the side to be read facing upward. When the operation is started, the original is transported by the paper feed roller 501 in order from the lowermost original of the set original, the original transported by the separation roller 502 and the separation pad 503 is separated, passes through the intermediate roller 504, and is registered by the registration roller 505. The skew is corrected and the conveyor belt 5
At 06, the document is conveyed onto the document glass 18, and immediately after the rear end of the document has passed the left end of the document scale 512, the conveyance belt 506 slightly reverses and stops.

As a result, the right end (rear end) of the original contacts the edge of the original scale 512 and the original is placed on the original glass 18.
Positioned accurately on top. At this time, the leading edge of the next document has reached the registration roller 505, so that the time required for transporting the next document is reduced.

In this state, the document reading section 10a performs scanning to read the front surface (lower surface) of the document. When the reading of the document is completed, the document is conveyed leftward by the conveyance belt 506, makes a U-turn by the reversing roller 507, and is discharged onto the discharge tray 511 by the discharge roller 509 through the upper side of the switching claw 508. At this time, the document is discharged with the reading surface (front surface) of the document facing upward.

Next, the panning single-sided mode will be described. The panning single-sided mode is possible, for example, when performing a single copy, and performs an operation in conjunction with the scanning system 10.
In other words, until the document passes through the registration roller 505, the operation is the same as that in the above-described single-sided mode. After that, the document is transported by the transport belt 506 at a constant speed corresponding to the copy magnification, and the reverse roller 507 and the like are directly Is discharged onto the paper discharge tray 511 through the During this time, the original reading section 10a is stopped at the right end of the original glass 18, and the original passes above the original, so that the surface of the original being conveyed is read.

Therefore, operations such as reverse positioning of the original in the one-sided mode and scanning and return of the original reading section 10a are not performed, and reading is performed at high speed.
In the follow-up double-sided mode, first, immediately after the document has passed the registration roller 505, the back side of the document is read by the document reading unit 10b, and then the front side is scanned by the document reading unit 10a by the same operation as the scan single-sided mode described above. Is read. That is, in this mode, only the back side of the document is read by panning. In the next high-speed mode, both sides of the document are read by panning.

Next, the high-speed mode will be described with reference to a timing chart shown in FIG. 7 and a block diagram of the image signal processing section 20 shown in FIG. The high-speed mode is a reading mode which is a feature of the present invention. The front and back sides of a double-sided original are sequentially read by the two original reading units 10a and 10b by panning. At this time, the original reading unit 10b
Thus, the reading of the back side of the document and the detection of the document length are performed, the document reading unit 10a moves to a reading position RPa corresponding to the detected document length, and the front side of the document is shot at that position.

First, a method of detecting the document length by the document reading unit 10b will be described. In the document transport section 500, the surface of the document transport path facing the document reading section 10b is painted black, and when there is no document, the document reading section 1
0b (photoelectric conversion element 17) detects the black level over the entire area in the main scanning direction.

When a document is conveyed, the output signal of the photoelectric conversion element 17 changes from a black level to a white level. This change point is detected as the leading edge of the document, and at the same time, the counting operation of the clock signal by the document length counter is started.

Thereafter, the output signal of the photoelectric conversion element 17 is
When a change point at which the white level changes to the black level over the entire area in the main scanning direction is detected, this is regarded as the rear end of the document, and the counting operation of the document length counter is stopped. Since the period of the clock signal and the document conveyance speed are constant, the count value of the document length counter at this time becomes a value corresponding to the document length.

In the high-speed mode, first, the switching circuit 201
Thus, the output of the photoelectric conversion element 17 of the document reading unit 10b is selected and input to the A / D converter 202.
In this state, the back side of the original is read by the original reading unit 10b by panning.

At the same time as detecting the trailing edge of the original,
By driving the scan motor M2, the home position (FIG. 1)
Is moved to the reading position RPa. The reading position RPa is located at a distance substantially equal to the length of the document from the home position of the document reading unit 10a, and is, for example, a position about several mm to several cm away from the reading position by the document reading unit 10b. The reading position RPa is set to the document reading unit 1
In consideration of the moving speed of 0a or the positioning accuracy, etc.,
It is set as close as possible to the home position. The movement to the reading position RPa is performed based on the count value of the above-described document length counter.

The moving speed of the document reading section 10a is set to be several steps higher than the conveying speed of the document, and its value is such that the leading edge of the document moves to the reading position RPa after the trailing edge of the document is detected. The document reading unit 10a is set to move faster from the home position to the reading position RPa than the document reading unit 10a.

After detecting the trailing edge of the original, the switching signal S
5 is output to the switching circuit 201, whereby the output of the photoelectric conversion element 16 of the original reading section 10a is selected and
It is input to the D converter 202. In this state, the surface of the original is read by the original reading unit 10a by panning.

As described above, in the high-speed mode, both sides of the original are read by panning, and after the reading of the back side of the original is completed, the front side of the original is read at the reading position RPa corresponding to the original length. A document of a size can always be read in the shortest time.

Since the image signals SD1 and SD2 from the photoelectric conversion elements 16 and 17 are switched by the switching circuit 201 and sequentially input to the A / D converter 202, a page memory for timing adjustment is not required. is there.

As described above, when reading both sides of a document, the respective document reading units 10a and 10b operate in a time series. Therefore, the switching circuit 201 switches and outputs image signals from the respective photoelectric conversion elements 16 and 17. Therefore, the processing circuit of the image signal processing unit 20 may be one system.

Returning to FIG. 2, on the operation panel OP, a liquid crystal touch panel 91, ten keys 92 for inputting the number and magnification, a clear key 93 for returning the number to the standard value "1", and copying are provided. Panel reset key 94 for returning set values and the like in machine 1 to standard values, stop key 95 for stopping copy operation, start key 96 for starting copy operation, and mode setting for setting copy mode A key 97 and mode display units 97a to 97d for displaying a copy mode are provided.

The operation panel OP is provided with a high-speed mode setting key 98 for setting a high-speed mode, and a high-speed mode display section 98a. LCD touch panel 9
1 displays various states of the copying machine 1 such as occurrence of a JAM, occurrence of a serviceman call, occurrence of a paper empty, operation modes of the copying machine 1 such as an exposure level, magnification, and paper, and other various information. Input for mode selection.

Next, the control section 100 will be described. 3 and 4 are block diagrams showing the configuration of the control unit 100 of the copying machine 1. The control unit 100 includes eight CPUs 101 to
108, each of these CPUs 101 to
8, ROMs 111-111 each storing a program.
118 and RA serving as a work area for program execution
M121 to M128 are provided. Note that the CPU 10
Reference numeral 6 is provided in the memory unit 30 (see FIG. 6).

The CPU 101 performs control relating to input of signals from various operation keys on the operation panel OP and display. The CPU 102 controls each unit of the image signal processing unit 20, and the CPU 103 controls the driving of the scanning system 10. The CPU 104 controls the print processing unit 40, the optical system 60, and the image forming system 70, and the CPU 105 controls the control unit 1
A process for adjusting the overall timing of 00 and setting the operation mode is performed.

The CPU 106 temporarily stores the read image data in a memory (code memory 306) by controlling the memory unit 30, reads out the image data, and outputs the read image data to the print processing unit 40. Thereby, the reading device I
The R and the printer device PRT are independently controlled to improve the copy speed.

The CPU 107 controls the document transport unit 500, and the CPU 108 controls the re-feed unit 600. Serial communication is performed between the CPUs 101 to 108 by interruption, and commands, reports, and other data are exchanged.

Next, each processing section for processing image data will be described. FIG. 5 is a block diagram of the image signal processing unit 20. The image signal processing unit 20 includes a switching circuit 201, A
/ D converter 202, shading correction section 203, color determination section 204, scaling processing section 205, and image quality correction section 20
6, etc.

The image signals SD 1 and SD 2, which are analog signals output from the respective photoelectric conversion elements 16 and 17, are input to a switching circuit 201. The switching circuit 201 has a C
Based on the switching signal S5 set by the PU 102, one of the image signals SD1 and SD2 is selectively switched and output to the A / D converter 202.

The image signals SD1 and SD2 are supplied to the A / D converter 20.
2, after performing analog processing such as amplification and waveform shaping, the reference voltage VRe set by the CPU 102.
Based on f, the data is converted into image data D of an 8-bit digital signal for each pixel.

The image data D is supplied to the shading correction unit 2
03, where shading correction is performed based on the correction data set by the CPU 102. Next, the color determining unit 204 determines the color of each pixel of the image data based on the color mode set by the CPU 102, and outputs 1-bit color data DC indicating whether or not the color is the specified specific color. .

Then, in the scaling section 205, the CP
An electrical scaling process is performed based on the magnification set by U102. Finally, the image quality correction unit 206 performs image quality correction such as γ correction based on the parameters set by the CPU 102, and then outputs the color data DC to the memory unit 30.

Next, the memory unit 30 will be described. FIG. 6 is a block diagram of the memory unit 30. The memory unit 30 includes a switching unit 301 and a CPU
A binary processing unit 302 for generating binary data based on the parameter settings from the code processing unit 106; a code processing unit 30 having a compression unit 311 and a decompression unit 312 which can operate independently of each other
5, a code memory 306 having a multi-port, a rotation processing unit 307, a multi-value processing unit 308 that creates multi-value data based on parameter settings from the CPU 106, and a CPU 106 that controls all of them. I have.

The switching unit 301 sets the connection state in accordance with a control signal from the CPU 106, and controls the flow of the image data D and the color data DC. The encoding unit 305 encodes and compresses the input image data D2a in real time for each line, and compares the data amount of the data before compression and the data amount of the data after compression for each line. , Only the data with the smaller data amount is written into the code memory 306. That is, the code memory 3
In 06, either uncompressed image data or compressed code data is written for each line.

Further, in accordance with a command from the CPU 106, the image data or code data written in the code memory 306 is read out, and if it is code data, it is expanded to generate image data D2b.

As described above, in the memory unit 30,
The input image data D2 (D2a) is compressed in real time for each line, and the data read from the code memory 306 is also decompressed in real time. An image memory (page memory) for storing the data D2a and an image memory (page memory) for storing the image data D2b for one page after decompression are not required, and the usage efficiency of the memory is improved and the mounting memory is accordingly reduced. The amount can be reduced.

Since the compressed code data is not stored in the code memory 306 as it is but is stored in a smaller amount than the data amount of the image data before compression, the use efficiency of the code memory 306 is further improved. At the same time, compression and decompression are performed in real time, and no time is required for the processing, thereby improving the data processing efficiency.

In the compression section 311 and the decompression section 312, since the data amount of the coded data to be transferred is always smaller than the data amount of the image data D2a on the same line, the ability to transfer the data amount of the image data D2a is provided. Would be good. Therefore, by adjusting the reading speed of the reading device IR and the system speed of the printer device PRT to the transfer capability of the image data D2a,
Processing can be performed at high speed without using an image memory as in the related art.

Although the above-described compressor 311 and decompressor 312 have been described as having a single compressor and decompressor, they may have a plurality of types of compressors and decompressors. Next, regarding the entire operation sequence of the copying machine 1 in the memory mode writing operation, each of the CPUs 101 to 101 will be described.
The following mainly describes the request command (Q), report (A), or data flow exchanged between the nodes 6. In the following figures, unimportant request commands or reports may be omitted.

FIG. 8 is a diagram showing an operation sequence of the memory mode write operation. As described above, in the memory mode writing operation, the image data read by the reading device IR is transferred to the code memory 306.

When the start key 96 of the operation panel OP is pressed and a read request is issued from the CPU 101 to the CPU 105 which manages the entire sequence, the CPU 105
Returns a read report to the CPU 101.

Then, a read request and a compression request from the CPU 105 to the CPU 106, a read request to the CPU 102, and
, A scan request is issued. Thereby, the CPU 106 stores the image data D2 from the image signal processing unit 20 in the code memory 306 with respect to the internal hardware.
Setting of the connection state of the switching unit 301 for transferring to the
Setting of a mode for binarization processing (for example, error variance method, threshold value for background erasure, binarization threshold value, etc.), compressor 3
Setting of 33 modes (for example, MH system), setting of a write address to the code memory 306, the number of data, and the like are performed. Then, scanning is started.

When the image area of the document is reached by scanning, read data (image data D2) is output to the memory unit 30 in accordance with the image processing mode set by the CPU 102.

In the memory unit 30, the input read data is compressed in real time for each line, and the code data or image data is sequentially stored in the code memory 306.

When the reading by scanning and the compression processing are completed, a reading completion report and a compression completion report are output from the CPU 106 to the CPU 105, and a compression completion report is output from the CPU 102.

Next, based on the flowchart, the copying machine 1
Will be described. FIG. 9 is a flowchart of the main routine of the CPU 101. After the initial setting (Step # 11), the internal timer is started and the routine time is monitored so as to be constant (Steps # 12, 1).
6) Input control processing and display control processing are performed on the operation panel OP and the like (steps # 13 and # 14), and other processing is performed (step # 15). Communication with the other CPUs 102 to 108 is performed by interrupt processing.

FIG. 10 is a flowchart of the main routine of the CPU 102. Data input switching processing for switching the image signals SD1 and SD2 from the photoelectric conversion elements 16 and 17 is performed (step # 23), and after input processing of image data is performed (step # 24), color discrimination processing, image processing, and image processing are performed. Perform data output processing and other processing (step #
25-28).

FIG. 11 is a flowchart of the main routine of the CPU 103. The CPU 103 controls the scanning system 10. Here, only the case where the original is a double-sided original will be described.

A command receiving process is performed (step # 3).
3) Scan control is performed according to the command (step # 34). Further, when a motor pulse interrupt occurs due to a motor pulse generated in synchronization with the rotation of the scan motor M2, the interrupt interval time of the motor pulse is measured (step # 36), the energization of the motor is turned on / off (step # 37), The number of motor pulses is counted (step # 38). Thus, the rotation of the scan motor M2 is controlled.

FIG. 12 is a flowchart of the main routine of the CPU 106. The CPU 106 controls the memory unit 30. A command reception process from another CPU is performed (step # 62), a status transmission process is performed (step # 63), and compression control is performed (step # 6).
5) Perform decompression control (step # 66) and perform sequence control (step # 68).

FIG. 13 is a flowchart of the main routine of the CPU 107. The CPU 107 includes the document transport unit 50
Control 0. The document is separated and the skew is corrected.
6 is performed (step # 73), and the document is conveyed to control the positioning of the document to a predetermined reading position by the conveyance belt 506 and the conveyance to the reversing roller 507 (step # 73). 74), a document reversing / discharging process for controlling whether the document that has reached the reversing roller 507 is discharged as it is or conveyed again toward the conveying belt 506 is performed (step # 75).

FIG. 14 is a flowchart of the input control process in step # 13. Every time the on-edge of the mode setting key 97 is detected (Yes in step # 101),
"Single-sided", "Dual-sided", "Single-sided", "Duplex-
Switch each copy mode of "double-sided" to circulation,
The respective mode display sections 97a to 97d are sequentially turned on (steps # 102 to # 108).

At this time, if a copy mode other than “one-sided-one-sided” is set (steps # 103, # 105, # 1)
07), a memory mode is set (step # 10)
9). In the case of the “single-sided-single-sided” copy mode (step # 108), if the mode is the multi-copy mode (yes in step # 110), the direct connection memory mixed mode is set (step # 111), and the single copy mode is set. If so (No in Step # 110), the direct connection mode is set (Step # 112).

Every time the on-edge of the high-speed mode setting key 98 is detected (step # 114), the mode is switched between the high-speed mode and the normal mode (steps # 115 and # 11).
7, 119) High-speed mode display section 9 according to the mode
8a is turned on or off (steps # 116 and # 11).
8).

If the ON edges of the mode setting keys 97 and 98 are not detected (NO in step # 114), the direct connection mode is set after performing the automatic clear (step # 120).

FIG. 15 is a flowchart of the data input switching process in step # 23. Here, the switching circuit 201 switches the image signals SD1 and SD2 output to the A / D converter 202.

First, it is determined whether or not the original to be read is a two-sided original according to the data set on the operation panel OP (step # 231). If the original is a two-sided original, the switching circuit 201 is first set to the original reading section 10b. The image signal SD2 is output by switching to the photoelectric conversion element 17 side (step # 232). After the trailing edge of the original is detected, the image signal SD1 is switched by switching to the photoelectric conversion element 16 side of the original reading section 10a. Output (Step # 23)
4).

When the original is not a double-sided original, the photoelectric conversion element 1
6 and outputs the image signal SD1 (step # 234). FIG. 16 is a flowchart of the command receiving process in step # 33.

In this command receiving process, the CPU 102
A scan mode for reading the front side of the document by panning or by scanning with a scanner is set in accordance with the command received from step # 251 (step # 251). Where C
The command received from the PU 102 is determined by operating the operation panel OP. When the high-speed mode setting key 98 is pressed to set the high-speed mode, a mode in which both sides are read by panning is set, and in the case of other normal modes, the respective reading modes are set. Then, the mode is set by another command (step # 252).

FIG. 17 is a flowchart of the scan control process in step # 34. Here, only the two-sided document reading mode will be described. In scan control,
First, the back side of the document is read by the panning shot by the photoelectric conversion element 17 of the document reading unit 10b (step # 26).
1). Here, the original is transported while the back side is read, and when the trailing end of the original is detected by the photoelectric conversion element 17 (Yes in step # 262), the detected original length is set in the memory Y (step # 262). # 263).

It is determined whether or not the mode is the high-speed mode (step # 264). If the mode is the high-speed mode, the scanning motor M2
To move the document reading unit 10a from the home position to the reading position RPa at a distance of Y (step # 265), and perform a panning shot of the conveyed document by the photoelectric conversion element 16 (step # 266). .

If the mode is the normal mode (No in step # 264), the process waits for the document to be set at a predetermined position on the platen glass 18 (step # 267). The scanner 10a is driven to scan the scanning length Y, and the surface of the document is read (step # 268).

FIG. 18 is a flowchart of the command receiving process in step # 62. If a command is received (Yes in step # 301), if it is a compression command, the compression state is set to "1" (steps # 304 and # 30).
5) If the command is a decompression command, the decompression state is set to "1" (steps # 306 and 307).

FIG. 19 is a flowchart of the status transmission process in step # 63. If there is a transmission status, it is transmitted (steps # 321 and 322).

FIG. 20 is a flowchart of the compression control process in step # 65. In the state "1", settings for compression processing such as XY length information, a write address to the code memory 306, and a compression method are performed, and accordingly, the contents of the management table MT1 are changed (step # 352). The state is set to "2" (step # 35)
3).

In the state "2", the setting is performed each time the compression processing for one memory area divided for every 32 Kbytes is completed (step # 358). When the compression processing for one page is completed, the compression is completed. The status is set (step # 356), and the state is set to "0" (step # 3)
57).

FIG. 21 is a flowchart of the memory mode process performed in the sequence control process of step # 68. IR control for controlling the reading device IR is performed (step # 451), and PR for controlling the printer device PRT is performed.
T control is performed (step # 452), and switching control is performed (step # 453).

FIG. 22 is a flowchart of the IR control process in step # 451. If there is a command from the CPU 105 of the reading device IR to the code memory 306 in the state "0", the state is set to "1" (steps # 471 and 472).

In the state "1", a read request is issued (step # 475), and the connection state of the switching unit 301 is set to the memory mode write operation (step # 47).
6) The state is set to "2" (step # 477).

In state "2", a compression request is issued and the state is set to "3" (steps # 479 and 480). In state "3", a scan request is issued to the scanner, and the state is set to "4" (steps # 481 and 482).

When the scan end signal is output from the scanner in state "4", the state is set to "5" (steps # 483 and 484). If the compression is completed in state "5", the state is set to "6" (step # 48).
5,486).

At state "6", the scanner reading is completed, and a task N is generated (steps # 491, 49).
2) If there is a next document, the state is set to "1" (steps # 493 and 494); if not, the state is set to "0" (step # 495).

FIG. 23 is a flow chart of the document conveying process in step # 74. If the reading mode is the high-speed mode, that is, if the front and back sides are in the panning mode (Yes in step # 601), the original is placed on the original platen glass 1.
The document is conveyed above the document reading unit 10a at a constant speed by the conveyance belt 506 without being stopped on the document 8 (step # 602). Here, the constant speed is a speed suitable for the transfer capability of the image data D2a.

When the reading mode is the normal mode, that is, in the case of the scanner scanning mode (step # 601)
No), the original is conveyed so as to be set at a predetermined position on the original platen glass 18 (step # 603). When the setting of the original is completed (YES in step # 604), the original reading unit 10a is driven, and the original is read. Is the original reading section 1
It is read by scanning 0a.

When the reading by the document reading section 10a is completed (YES in step # 605), the conveyance belt 50
6 is driven to rotate in the normal direction, and is transported to the reversing roller 507 (step # 606).

In the above-described embodiment, the photoelectric conversion element 17 of the original reading section 10b is used as the detecting means for detecting the original length. However, a dedicated sensor for detecting the original length is provided in the original conveying path. it may be provided to. Alternatively, a document placed on the document feed tray 510 may be detected by a number of sensors, the size of the document may be detected by a combination of the detection signals, and the document length may be determined from the document size. Further, the document length or the document size may be input from the operation panel OP.

In the above-described embodiment, the circuit configuration of the control unit 100, the processing contents of each of the CPUs 101 to 108, the processing sharing, the software structure, and the structure of each unit of the copying machine 1 are described below.
Various changes can be made in accordance with the gist of the present invention.

[0103]

According to the present invention, a page memory for temporarily storing an image signal output from an image sensor is not required, and originals of various sizes can always be read in the shortest time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional front view showing an entire configuration of a copying machine according to the present invention.

FIG. 2 is a front view of an operation panel.

FIG. 3 is a block diagram illustrating a configuration of a control unit of the copying machine.

FIG. 4 is a block diagram illustrating a configuration of a control unit of the copying machine.

FIG. 5 is a block diagram of an image signal processing unit.

FIG. 6 is a block diagram of a memory unit.

FIG. 7 is a timing chart showing a flow of an image signal in a high-speed mode.

FIG. 8 is a diagram showing an operation sequence of a memory mode write operation.

FIG. 9 is a flowchart of a main routine of the CPU 101.

FIG. 10 is a flowchart of a main routine of a CPU 102;

FIG. 11 is a flowchart of a main routine of a CPU 103.

FIG. 12 is a flowchart of a main routine of a CPU 106.

FIG. 13 is a flowchart of a main routine of a CPU 107.

FIG. 14 is a flowchart of an input control process.

FIG. 15 is a flowchart of a data input switching process.

FIG. 16 is a flowchart of a command receiving process.

FIG. 17 is a flowchart of a scan control process.

FIG. 18 is a flowchart of a command receiving process.

FIG. 19 is a flowchart of a status transmission process.

FIG. 20 is a flowchart of a compression control process.

FIG. 21 is a flowchart of a memory mode process.

FIG. 22 is a flowchart of an IR control process.

FIG. 23 is a flowchart of a document conveying process.

[Explanation of symbols]

 IR reader (image reader) 10a document reader (second reader) 10b document reader (first reader, detector) 100 controller (controller) 500 document transporter (document transporter)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Muramatsu 2-3-3 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB Name) H04N 1/04-1/207 G01G 1/00 400-460 G03B 27/50 G03G 15/00 107 G03G 15/04 113-115

Claims (1)

(57) [Claims] A document conveying means for conveying a document; a detecting means for detecting a length of the document;In the first reading position, While the original is being transported,
First reading means for reading an image on one surface;Downstream of the first reading position in the document transport direction
In a second reading position located on the side Transfer of manuscript
Second reading means for reading an image on the second surface during the feeding;Moving the second reading means from the standby position to the second reading position;
Driving means for moving the  The detection meansAfter the detection byBased on the detection result
The second reading meansBut,The first reading means
LaSaidOriginal lengthMore than predetermined lengthDistantThe second
readingpositionThe leading end of the document is at the second reading position
Faster than moving toTo move, The driving means
An image characterized by comprising control means for controlling
Reader.