JPH09138848A - Picture reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a scanner function without using a buffer memory circuit with large capacity by interrupting/resuming a picture read operation and the transfer operation of picture data when an interruption/resumption signals are outputted from an external device. SOLUTION: When a PAUSE signal interrupting the read operation from the external device 4 is outputted, the CPU circuit 48 of a control part 45 in a scanner control unit 33 refers to the content of a motor through-up table stored in an EPROM circuit 50 is referred to and a timer counter function provided inside is operated. The rotation speed of a flat bed motor 32 is gradually dropped within a range where picture data is not disturbed, and the read operation is finally stopped. Then, a CPU circuit 48 operates a timer counter function and the rotation speed of the flat bed motor 32 is gradually raised and the read operation speed is finally set to be the regular one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device or a digital copying machine which is provided in a digital copying machine or the like, in which image data is provided in the digital copying machine by a main scanning valid signal, a sub scanning valid signal and an image data transfer clock signal. The present invention relates to an image reading device for transferring to an external device outside the machine.

[0002]

2. Description of the Related Art As a copying machine for copying an original document, a "digital copying machine" disclosed in Japanese Patent Laid-Open No. 7-107218, an "image reading apparatus" disclosed in Japanese Patent Laid-Open No. 7-131593, and a special type are conventionally known. An "image reading device" disclosed in Kaihei 7-123206 is known. In this case, the "digital copying machine" disclosed in Japanese Patent Laid-Open No. 7-107218 is installed in the system control unit.
An image memory for accumulating image data (image data) obtained by the reading operation of the scanner reading unit is provided, and the image data obtained by the scanner reading unit is stored in the image memory based on the setting contents of the mode switch. After that, by providing a mode for sending to the printer section and a mode for sending the image data obtained by the scanner reading section directly to the printer section, another image is added to the image data obtained by the scanner reading section. It is possible to synthesize and overwrite. The "image reading device" disclosed in Japanese Patent Laid-Open No. 7-131593 controls a stepping motor that conveys an original document by a control unit and an image processing unit that processes image data of the original document to control the original document. The image reading operation can be temporarily interrupted, and after the temporary reading operation is interrupted, when the reading operation is restarted, the rotation speed of the stepping motor and the processing speed of the image processing unit are sequentially set, Even if the reading operation of the document is temporarily interrupted by returning to the normal value,
The image data output from the image processing unit is prevented from deteriorating. Further, the "image reading device" disclosed in Japanese Patent Laid-Open No. 7-123206 discloses a stepping motor that moves a fluorescent lamp and an original relatively.
When an image of a document illuminated by the fluorescent lamp is read and image data is generated, the number of steps for driving the stepping motor and the reading density are linked based on the contents calculated in advance, so that the CPU Without changing the rotation speed of the stepping motor for moving the document or the rotation speed of the stepping motor for driving the fluorescent lamp, or changing the rotation speed of the stepping motor. Documents can be read even during through-up and through-down).

[0003]

By the way, in such a copying machine, especially a digital copying machine, an image reading device provided in the digital copying machine and each device and external equipment provided in the digital copying machine are provided. As an interface for connecting an external device, a first type interface (for example, an interface of SCSI standard) for transferring image data to the external device while handshaking with the external device, a main scanning effective signal, a sub-scanning effective signal, A second type interface (video interface) that unilaterally transfers image data to an external device using an image data transfer clock signal or the like is known. In this case, the image reading device having the first type interface is
Since it is a general-purpose interface such as SCSI,
Although it has the advantage that it can be easily connected to a general-purpose external device such as a personal computer, it requires a control circuit such as a SCSI control circuit to be mounted, resulting in a complicated configuration and an increase in cost. There was a problem. Further, since the image reading apparatus having the first type interface transfers image data by handshaking with the external apparatus, it is impossible to secure a sufficient reading speed when the processing capacity of the external apparatus is low. was there. Further, the image reading device having the second type interface has a drawback that it cannot be easily connected to a general-purpose external device such as a personal computer device, but since the interface circuit configuration can be simplified, It has the advantage that it does not cost any money. Further, since the image reading apparatus having the second type interface unilaterally transfers the image data to the external apparatus,
The advantage of being able to secure a sufficient reading speed,
It also has a restriction that image data cannot be transferred unless the external device has sufficient processing capability. For these reasons, in a digital copying machine, the second type interface is usually used for the purpose of simplifying the configuration of the image reading device and reducing the cost, and for the purpose of using the image reading device at a sufficient reading speed. When used and performing a normal copying operation, the image data output from the image reading apparatus is sent to the image printing apparatus without being temporarily stored in the buffer memory circuit for one page.

However, in a system such as a digital copying machine, when a scanner function is prepared and image data is transferred to an external device such as a host computer provided separately from the digital copying machine, regardless of the memory capacity. Since the image data is sent unilaterally from the scanner function, a buffer memory circuit for one page is prepared, and the image data obtained by the scanner function is temporarily stored in the buffer memory circuit and then transferred to the host computer device or the like. Therefore, a large-capacity memory (for example, 8 bits / A3 / 400
It is necessary to prepare 32 megabytes (dpi), which causes a problem that the cost is extremely high. In this regard,
The "digital copying machine" disclosed in Japanese Unexamined Patent Publication No. 7-107218 has the same problem because it is premised on providing a large-capacity image memory, and is disclosed in Japanese Unexamined Patent Publication No. 7-131593. In the "image reading device", the operation panel etc.
Although it is possible to control the image data transfer speed by suspending / resuming the image reading operation by an instruction from the control unit provided inside the apparatus, an instruction from an external device such as a host computer device Since it is not possible to suspend / resume, there is a problem that a large capacity buffer memory circuit is required when transferring image data to a host computer device or the like. Further, in the "image reading device" disclosed in Japanese Patent Application Laid-Open No. 7-123206, according to the rotation speed of the stepping motor,
Although the reading density can be adjusted, the image reading operation cannot be suspended / restarted by an instruction from the host computer device.
In the same way as the "image reading device" disclosed in the publication, when transferring image data to a host computer device or the like,
There is a problem that a large capacity buffer memory circuit is required.

In view of the above situation, according to the present invention, in the first aspect, by generating a signal for suspending / resuming the transfer of the image data on the external device side, the image data is transferred to the external device in a system such as a digital copying machine. An object of the present invention is to provide an image reading apparatus that can realize a scanner function without using a large-capacity buffer memory circuit even if a second-type interface for unilaterally transferring data is used. Further, according to claim 2, the transfer of the image data can be temporarily stopped without significantly changing the current interface signal configuration (while maintaining compatibility), and thus in a system such as a digital copying machine. , Without using a large capacity buffer memory circuit,
An object is to provide an image reading device that can realize a scanner function. In claim 3,
When the image data transfer is temporarily stopped, the reading operation is smoothly interrupted / restarted so that image distortion does not occur even when the reading operation is interrupted / restarted. An object of the present invention is to provide an image reading apparatus that can realize a scanner function without using a large capacity buffer memory circuit.

[0006]

In order to achieve the above object, according to the present invention, in claim 1, an image of a document to be read is read, and a main scanning effective signal LGATE, a sub-scanning effective signal FGATE and an image are read. In the image reading device that transfers the specified bit component of the image data VDT0-7 obtained in the reading operation to the external device together with the data transfer clock signal VCLK, the suspend / resume signal (PAUSE signal) is output from the external device. When this is done, the image reading operation of the original document and the image data transfer operation are interrupted / restarted. According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the reading operation is interrupted when the image reading interruption is instructed by the interruption / restart signal output from the external device, and the sub-scanning valid signal FGATE is also issued. The main scanning enable signal LGATE is made inactive with the image data V
The transfer of the designated bit component of DT0-7 is interrupted, the reading operation is restarted when the image reading restart is instructed by the suspend / resume signal output from the external device, and the sub-scanning valid signal FGATE is activated. The main scanning enable signal LGATE is activated while keeping the above state, and the transfer of the designated bit component of the image data VDT0-7 obtained by the reading operation is restarted together with the image data transfer clock signal VCLK. According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, when the image reading interruption is instructed by the interruption / restart signal output from the external device, the reading speed in the sub-scanning direction. Is gradually delayed, and the period of the main-scanning valid signal LGATE that has been output in a predetermined period is gradually lengthened, and after a predetermined time, the main-scanning valid signal LGATE is increased.
Of the main scanning effective signal LGATE which is stopped while gradually increasing the reading speed in the sub-scanning direction when the image reading restart is instructed by the suspend / resume signal output from the external device. It is characterized in that the output is restarted, the cycle is gradually shortened, and after a predetermined time, the main scanning effective signal LGATE having a predetermined cycle is obtained.

In the above arrangement, the main scanning effective signal LGAT is read while the image of the original document to be read is read.
In the image reading device which transfers the designated bit component of the image data VDT0-7 obtained by the reading operation to the external device together with E, the sub-scanning valid signal FGATE, and the image data transfer clock signal VCLK, interruption from the external device / When the restart signal (PAUSE signal) is output, the image reading operation of the original document and the image data transfer operation are suspended /
A second type interface for unilaterally transferring image data to an external device in a system such as a digital copying machine when a signal for suspending / resuming the transfer of the image data is output from the external device by restarting. Even without using a large capacity buffer memory circuit,
Realize the scanner function. According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the reading operation is interrupted when the image reading interruption is instructed by the interruption / restart signal output from the external device, and the sub-scanning valid signal FGATE is also issued. The main scanning enable signal LGATE is made inactive with the image data V
The transfer of the designated bit component of DT0-7 is interrupted, the reading operation is restarted when the image reading restart is instructed by the suspend / resume signal output from the external device, and the sub-scanning valid signal FGATE is activated. The main scanning enable signal LGATE is made active while keeping the above state, and the transfer of the designated bit component of the image data VDT0-7 obtained by the reading operation is resumed together with the image data transfer clock signal VCLK, whereby the current interface The image data transfer is temporarily stopped without significantly changing the signal structure (maintaining compatibility), so that the scanner can be used in a system such as a digital copying machine without using a large capacity buffer memory circuit. Realize the function. According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, when the image reading interruption is instructed by the interruption / restart signal output from the external device, the reading speed in the sub-scanning direction. Of the main scanning enable signal LGA that was output at a predetermined cycle
When the period of TE is gradually lengthened, the output of the main scanning valid signal LGATE is stopped after a predetermined time, and the image reading restart is instructed by the suspend / resume signal output from the external device, the direction of the sub scanning is changed. By gradually increasing the reading speed, restarting the stopped output of the main scanning valid signal LGATE, gradually shortening the cycle, and setting the main scanning valid signal LGATE of a predetermined cycle after a predetermined time, When the transfer of image data is temporarily stopped, the reading operation is smoothly interrupted / restarted, and image distortion is not generated even when the reading operation is interrupted / restarted. A scanner function is realized without using a buffer memory circuit having a capacity.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a block diagram showing an example of an image reading apparatus according to the present invention. An image reading device 1 shown in this figure is a document reading device 2 for reading an image of a document, and an automatic document feeding device mounted on the document reading device 2 for automatically feeding the document to the document reading device 2. 3 is provided, and directly on the document reading device 2,
An image of the document placed on the document reading device 2 is read by the placed document or the automatic document feeding device 3, and the image data obtained by this is transferred to an external device 4 (see FIG. 2) such as a host computer device. Forward. In this case, the automatic document feeder 3 is attached to the upper and lower sides of the document reading device 2 and a device casing 5 which is rotatably supported by an upper and lower sides of the device casing 5 to be automatically fed. Is mounted on the original tray 6 and the original tray 6 which is rotatably mounted in the apparatus casing 5, and is placed on the original tray 6 by a driving force obtained by a paper feed motor (not shown). Pick-up roller 7 that takes out the originals one by one
And a registration roller pair 8 rotatably mounted in the device casing 5 for adjusting the delivery timing of the document picked up by the pickup roller 7, and rotatably provided in the device casing 5. A transport drum 9 that winds up and transports the document sent from the roller pair 8 and a plurality of transports that are rotatably mounted in the device casing 5 and press the document sent from the registration roller pair 8 against the transport drum 9. And a roller 10.

Further, the automatic document feeder 3 includes a device casing 5.
A delivery guide path 12 for guiding a document placed inside the apparatus and conveyed by the conveyance drum 9 onto a sheet ejection tray 11 formed on the apparatus casing 5, and a conveyance drum rotatably arranged in the apparatus casing 5. A plurality of paper discharge roller pairs 13 that conveys the document guided to the paper discharge guide path 12 to the paper discharge tray 11 side, and a conveyance drum 9, a conveyance roller 10, and a paper discharge that are arranged in the device casing 5. A conveyance motor (DF motor) 14 for driving the roller pair 13 and the like, a paper size sensor 15 for detecting the size of the original document arranged in the device casing 5 as shown in FIG. 2, and whether the original document is correctly fed or not. A feed sensor 16 for detecting the position of the document, a registration sensor 17 for detecting the position of the leading edge of the document at the pair of registration rollers 8,
It is provided with a feed clutch 18 which is disposed in the device casing 5 and which interrupts the conveyance of the document.

The paper size sensor 15, the feed sensor 16, and the registration sensor 17 are used to detect the size of the document, the state of conveyance, the position of the leading edge of the document, etc., and based on a control signal output from the document reading device 2, a paper feed motor. , The conveyance motor 14, the feed clutch 18, etc. are operated, and the pickup tray 7 is used to move the document tray 6
The originals placed on the upper side are taken out one by one, and the originals sent out from the registration roller pair 8 by the conveying drum 9 and the respective conveying rollers 10 are rolled up by the registration roller pair 8 while the feeding timing is set. The document is conveyed to the reading position B, and the document reading device 2 is made to read the image of the document. After that, the conveyance drum 9 is further conveyed to guide the document whose image has been read to the paper ejection guide path 12, and the paper ejection tray 11 formed on the upper part of the device casing 5 by each paper ejection roller pair 13. Discharge on top.

Further, the document reading device 2 includes a device casing 20 formed in a box shape as shown in FIG. 1, and a contact glass 21 fitted in an opening formed in the upper portion of the device casing 20. The first traveling body 22 arranged in the apparatus casing 20 and transported in the direction of arrow A, and the original or reading position B arranged on the first traveling body 22 and placed on the contact glass 21 are displayed. An illumination lamp 23 such as a xenon lamp for illuminating a document passing therethrough, a first mirror 24 arranged on the first traveling body 22, for receiving reflected light (optical image) from the document and reflecting the same. A second traveling body 25, which is disposed in the enclosure 20 and is transported in the direction of arrow A at a speed half that of the first traveling body 22, and is disposed on the second traveling body 25 and has the first mirror. Second and third for further reflecting the optical image reflected at 24 And Ra 27, device disposed enclosure 20, and a lens 28 for condensing light image reflected by the third mirror 27.

Further, the document reading device 2 includes a device casing 20.
A sensor block unit (SBU) 29, which is disposed inside the device, receives the optical image collected by the lens 28, and generates an electric signal (image data), and a plurality of pulleys that are disposed inside the device casing 20. 30, multiple drive belts 31
A flat bed motor (traveling body motor) 32 for traveling the first traveling body 22, the second traveling body 25 and the like at a designated speed via the sensor block unit 29. Scanner control unit (SCU) 3 that processes image data output from
3, an image processing unit (IPU) 34 disposed in the device casing 20, receiving image data output from the scanner control unit 33, performing image processing on the image data, and returning the image data to the scanner control unit 33. As shown in FIG. 2, the power supply unit (PSU) 3 is arranged in the device casing 20 and supplies a DC power supply voltage of "+ 5V", "± 12V", "+ 24V" to the scanner control unit 33.
5 is provided.

Further, the document reading device 2 includes a device casing 20.
The scanner control unit 33 is disposed inside
A lamp regulator 1 that generates a high voltage to light the lighting lamp 23 based on a control signal output from the lamp regulator 1.
9 and the automatic document feeder 3 arranged in the device casing 20.
A platen open detection sensor 36 for detecting whether or not the upper part of the document reading device 2 is opened by being lifted up,
The contact glass 21 is disposed inside the device casing 20.
Is a paper size sensor 37 for detecting the size of the original placed above and the first and second traveling bodies 22, 25 disposed in the device casing 20 at the home position (initial position)? A home position sensor 38 for detecting whether or not it is provided.

When a document is placed on the document tray 6 of the automatic document feeder 3, the first and second traveling bodies 22 and 25 are moved to a position corresponding to the image reading position B, and While stopped at the position, the automatic document feeder 3 is operated with the illumination lamp 23 turned on, and the originals to be read images are taken out one by one. After that, while the operation of the automatic document feeder 3 is controlled so that the taken-out document is transported by the transport drum 9, when this document passes the document reading position B, it is placed on the first traveling body 22. The first mirror 24 is used to capture the optical image of the original document, and the second and third optical members arranged on the second traveling member 25 are arranged.
After reflecting it by the mirrors 26 and 27, the CCD 28 on the sensor block unit 29 is reflected by the lens 28.
It is condensed on 9 and converted into image data,
The specified image processing is applied to this image data,
Transfer to the external device 4. Further, if the document to be read is placed on the contact glass 21 while the document is not placed on the document tray 6 of the automatic document feeder 3, the document is placed on the first traveling body 22. Lighting lamp 2
In the state where 3 is turned on, while moving the first and second traveling bodies 22 and 25 respectively at the designated moving speed, the light of the original is reflected by the first mirror 24 arranged on the first traveling body 22. After capturing the image and reflecting it by the second and third mirrors 26 and 27 arranged on the second traveling body 25, the sensor block unit 29 is moved by the lens 28.
The light is condensed on the upper CCD 39 and converted into image data, and the image data is subjected to designated image processing and transferred to the external device 4.

Next, referring to the block diagram shown in FIG. 2, a sensor block unit 29 provided in the document reading device 2, a scanner control unit 33, and
The image processing unit 35 and the image processing unit 35 will be described in detail. First, the sensor block unit 29 receives an optical image of a document condensed by the lens 28, generates an electric signal (image signal) in an analog signal format, and divides this image signal into odd bits and even bits. The CCD 39 for outputting and the image signals of odd-numbered bits and even-numbered bits output from the CCD 39 are respectively taken in, the dark potential portion is removed, and the odd-numbered bits and the even-numbered bits are combined to generate an image signal having a predetermined amplitude gain. The analog ASIC circuit 40 to be generated and this analog ASIC circuit 40
A / D converter circuit 41 for A / D converting the image signal output from the A / D converter to generate image data in a digital signal format.
Based on the signal from the scanner control unit 33, the CCD 39, the analog ASIC circuit 40,
And a G / A circuit 42 for controlling the A / D converter circuit 41. Based on the signal from the scanner control unit 33, the optical image of the document condensed by the lens 28 is converted into an odd-numbered bit signal and an even-numbered bit image signal in analog signal format, and these are combined to generate one image signal. At the same time, this image signal is A / D converted to generate image data, which is supplied to the scanner control unit 33.

Further, the image processing unit 3
Reference numeral 4 is connected to the scanner control unit 33 via the connector 65, and takes in a video signal output from the scanner control unit 33 based on an image processing instruction output via the CPU bus 43 of the scanner control unit 33. In addition, the IEP circuit 44 for performing image processing according to the image processing instruction is provided, and the video signal output from the scanner control unit 33 is fetched based on the image processing instruction from the scanner control unit 33, and the specified image processing is performed. Then, the image-processed video signal is transferred to the connector 65.
And is supplied to the scanner control unit 33 via. The scanner control unit 33 includes a control unit 45 that performs various control processes and data processes based on a preset program and an instruction from the external device 4, and the sensor block based on the instruction from the control unit 45. While controlling the unit 29, the image data output from the sensor block unit 29 is processed to generate a video signal, and the video signal is processed by the image processing unit 34 directly or by the external device 4 A process and control unit that supplies the control unit 45 with the image processing unit 46 to be transferred, the detection results output from the automatic document feeder 3, and the detection results output from the sensors in the device casing 20. Based on an instruction from 45, the automatic document feeder 3, the sensor block unit 29, the flatbed Motor 32, and a driver unit 47 for performing processing such as control of the lamp regulator 19. The detection result output from the automatic document feeder 3 and the detection result output from each sensor in the device housing 20 are processed based on a preset program and an instruction from the external device 4 to automatically perform processing. The original feeding device 3, the sensor block unit 29, the flat bed motor 32, and the lamp regulator 19 are controlled to read the image of the original, and the image data obtained thereby is subjected to image processing to generate a video signal. Transfer to the external device 4.

In this case, the control unit 45 performs various controls based on a preset program, a detection signal supplied from the driver unit 47 indicating the operating state of each unit of the device, a PAUSE signal output from the external device 4, and the like. A CPU circuit 48 for performing instructions and data processing, a CPU bus 43 for connecting the CPU circuit 48, the driver unit 47, the image processing unit 46, etc., and a C bus connected to the CPU bus 43.
An SRAM circuit 49 which is used as a work area or a data storage area of the PU circuit 48, and an EPROM circuit 5 which is connected to the CPU bus 43 and stores various data used by the CPU circuit 48 and a motor through-up table.
0, and an EEPROM circuit 51 which is connected to the CPU circuit 48 and stores a program for defining the operation of the CPU circuit 48 and the like. When an operation panel (not shown) is operated to input an image reading instruction of a document, a detection signal supplied from the driver unit 47 based on a preset program and indicating an operation state of each unit of the apparatus. To check the state of each part of the device, and based on the check result, various control signals and main scanning synchronization signal L
Generates SYNC ', main scanning valid signal LGATE', DF motor clock signal, FB motor clock signal, etc.,
While supplying these to the image processing section 46, the DF motor clock signal, the FB motor clock signal, and the control signal are supplied to the driver section 47, and the flat regulator motor 32 is operated while operating the lamp regulator 19.
(Or, the automatic document feeder 3) is operated to read the document, and the image processing unit 46 is caused to process the image data obtained thereby.

At this time, if the PAUSE signal for interrupting the reading operation is output from the external device 4 as shown in FIG. 3A, the CPU circuit 48 of the control unit 45 causes the EPRO signal to be output.
Referring to the contents of the motor through-up table stored in the M circuit 50, the timer counter function provided inside is operated, and the main output is performed at a constant cycle as shown in FIG. 3 (c). Scan sync signal LSYNC ', main scan enable signal LGATE', DF motor clock signal, F
Even if the inertia of the drive system driven by the flat bed motor 32 (or the conveyance motor 14 of the automatic document feeder 3) is large, the image data is disturbed by sequentially increasing the generation cycle of the B motor clock signal and the like. The flatbed motor 3 as shown in FIG.
The rotation speed of 2 (or the conveyance motor 14 of the automatic document feeder 3) is gradually decreased, and the reading operation is finally stopped.

After that, if the PAUSE signal for interrupting the reading operation is no longer output from the external device 4, the control unit 45
The CPU circuit 48 refers to the contents of the motor through-up table to operate the timer counter function provided therein, and as shown in FIG. 3C, the main scanning synchronizing signal LSYNC 'and the main scanning valid signal are supplied. LGATE ',
The generation of the DF motor clock signal, the FB motor clock signal, etc. is started and the generation cycle thereof is sequentially shortened so that the flat bed motor 32 (or the conveyance of the automatic document feeder 3 is carried out as shown in FIG. 3B). Motor 14)
The rotation speed of is gradually increased to finally reach the normal reading operation speed. During this period, the sub-scanning valid signal FGATE is held in the valid state (ON state) as shown in FIG.

The driver section 47 is provided in the apparatus casing 20 as a result of detection by the paper size sensor 15 provided in the automatic document feeder 3, a result of detection by the feed sensor 16, a result of detection by the registration sensor 17. Detection result of the pressure plate open detection sensor 36, the paper size sensor 3
7 and the detection result of the home position sensor 38 and the like and supply them to the control unit 45. Based on the control signal output from the control unit 45, the feed clutch 18 and the lamp regulator 19 of the automatic document feeder 3.
External input / output circuit 52 for performing processing for controlling
And a DF motor driver circuit 53 that takes in a DF motor clock signal output from the control unit 45 based on an instruction from the external input / output circuit 52 and drives the conveyance motor 14 of the automatic document feeder 3 to rotate it. An FB motor driver circuit 54 that receives an FB motor clock signal output from the control unit 45 based on an instruction from the external input / output circuit 52, drives the flat bed motor 32, and rotates the flat bed motor 32.

Then, the detection result of the paper size sensor 15 provided in the automatic document feeder 3, the detection result of the feed sensor 16, the detection result of the registration sensor 17,
Pressure plate open detection sensor 36 provided in the device casing 20
Of the paper size sensor 37, the detection result of the home position sensor 38, and the like are supplied to the control unit 45, and the lamp lighting is instructed by the control signal output from the control unit 45. During this time, the lamp regulator 19 is operated to turn on the illumination lamp 23. Further, when the driving of the carry motor 14 is instructed by the control signal output from the control unit 45, the DF motor clock signal output from the control unit 45 is taken in and the DF motor clock signal is output according to the number of clocks of the DF motor clock signal. When the conveyance motor 14 of the automatic document feeder 3 is rotated by the rotation angle, and when the driving of the flat bed motor 32 is instructed by the control signal, the control unit 45.
The FB motor clock signal output from the FB motor clock signal is taken in and the flat bed motor 32 is rotated by a rotation angle corresponding to the number of clocks of the FB motor clock signal.

Further, the image processing section 46 responds to an FB motor clock signal for driving the flat bed motor 32 and a DF motor clock signal for driving the carry motor 14 based on an instruction from the control section 45, and then the sensor block unit. 29, a process of controlling 29, a process of converting the optical image condensed by the lens 28 into an electric signal by the sensor block unit 29, a process of taking in the image data obtained by the conversion process, and a shading process for the image data. Processing for performing correction, gamma correction, MTF correction, and the like, image data obtained by binarizing the corrected image data, a page synchronization signal, a line synchronization signal, and an image clock signal are used as video signals, and the connector 65 is connected. A process for supplying the image processing unit 34 to the image processing unit 34 via the control unit 45. The 3SIP performing the main scanning synchronization signal LSYNC outputted from the control unit 45 based on the instructions ', a main scanning effective signal LGATE' the main scanning synchronization signal LSYNC, processing, etc. to convert the main scan valid signal LGATE
Based on an instruction from the circuit 55 and the control unit 45, the third S
The SEL circuit 56 for selecting either the video signal output from the IP circuit 55 or the video signal output from the image processing unit 34 via the connector 65, and the video signal selected by the SEL circuit 56 An RS422 driver circuit 57 that converts the serial signal into the RS422 format and transfers the serial signal to the external device 4 is provided.

While controlling the sensor block unit 29 in accordance with an FB motor clock signal for driving the flat bed motor 32 and a DF motor clock signal for driving the carry motor 14 based on an instruction from the control section 45, After the image data output from the sensor block unit 29 is taken in, designated correction processing is performed and binarized, the image data obtained by this binarization processing, a page synchronization signal, a line synchronization signal, and an image are obtained. The clock signal and the video signal are supplied to the image processing unit 34, and the image processing unit 34 is caused to perform the image processing designated by the control unit 45. Of the video signal obtained by this or the video signal before the image processing, the control unit 45 Select the video signal specified by, and convert it to RS422 format serial signal. Te, and transfers to the external device 4.

At this time, in the third SIP circuit 55, as shown in FIG. 4, a synchronizing signal generator provided inside,
A counter circuit 58 for counting motor clock signals such as DF motor clock signals and FB motor clock signals;
A register circuit 59 that fetches and holds the compared value supplied from the CPU bus 43 of the control unit 45, compares the compared value held by the register circuit 59 with the count output value of the counter circuit 58, A comparison circuit 60 that generates a match detection signal (ON signal) when these match.
When the coincidence detection signal is output from the comparison circuit 60, the main scanning synchronization signal LSYNC ′ is output from the control unit 45.
And a line valid signal generation circuit 6 for generating a line valid signal when the
When the main scanning synchronization signal LSYNC ′ is supplied from the control unit 45 in the state where the line valid signal is output from 1, the AND gate circuit 62 that generates the main scanning synchronization signal LSYNC and the line valid signal generation circuit 61. When the main scanning effective signal LGATE ′ is supplied from the control unit 45 while the line effective signal is being output from the synchronizing signal generating unit 64, the AND gate circuit 63 generates the main scanning effective signal LGATE. Thus, the main scanning synchronization signal LSYNC is generated at a timing corresponding to the reading density designated by the compared value and the number of clocks of the motor clock signal.
And a main scanning enable signal LGATE.

As a result, the stepping motors constituting the carry motor 14 and the flat bed motor 32 rotate by one step with one clock of the motor clock signal,
When the drive system is configured so that the document set on the first traveling body 22 or the automatic document feeder 3 is conveyed by 1/400 inch in 6 steps, the reading density when reading the document is as follows: If 400 dpi is specified,
The compared value indicating “6” is output from the control unit, and FIG.
Each time the motor clock signal is supplied to the counter circuit 58 for 6 clocks as shown in (c) and (d) of FIG.
When the coincidence detection signal is output from the comparison circuit 60 as shown in (e) and the main scanning synchronization signal LSYNC 'is supplied from the control unit 45 as shown in FIG. 5 (a), as shown in FIG. 5 (f). A line valid signal is output from the line valid signal generation circuit 61. As shown in FIGS. 5A and 5B, the control unit 4
5 outputs the main-scanning synchronization signal LSYNC 'and the main-scanning valid signal LGATE', FIG. 5 (g), (h)
As shown in FIG. 5, the AND gate circuits 62 and 63 output the main scanning synchronization signal LSYNC and the main scanning effective signal LGATE, respectively. During this period, the sub-scanning valid signal FGATE is held in the valid state (ON state) as shown in FIG. Similarly, if 200 dpi is designated as the reading density when reading a document, the conveyance motor 14
When 12 clocks forming the motor clock signal are supplied to the stepping motor forming the flat bed motor 32 or the flat bed motor 32, the original set in the first traveling body 22 or the automatic document feeder 3 is Since the paper is conveyed by 200 inches, the compared value indicating "12" is supplied from the control unit 45 and set in the register circuit 59. Based on the compared value set in the register circuit 59, the above-described comparison is performed. The action is taken. And FIG.
The sub-scanning synchronization signal FSYNC is output as shown in (a), the sub-scanning valid signal FGATE is activated as shown in FIG. 6 (b), and the main scanning synchronization signal LSYNC is output as shown in FIG. 7 (a). Then, while the main scanning enable signal LGATE is active as shown in FIG. 7B, it is output from the image processing unit 46 by the external device 4 as shown in FIGS. 6C and 7B. The external device 4 is configured to capture the effective image data of the video signal.
When the PAUSE signal is output from the external device 4, the control unit 45 inactivates the main-scanning enable signal LGATE while keeping the sub-scanning enable signal FGATE active, so that the external device 4 outputs the PAUSE signal and the image is displayed. Even when the image reading operation of the document is interrupted by the reading device 1, the capturing of the video signal output from the image processing unit 46 can be stopped by the external device 4, and the video caused by the interruption of the reading operation of the document image is stopped. Signal transfer mistakes can be eliminated.

Further, when the PAUSE signal is output from the external device 4, the control unit 45 causes the motor clock signal, the main scanning synchronizing signal LSYNC ', and the main scanning valid signal LG.
While gradually increasing the generation cycle of ATE ', etc., D
When the generation cycle of the F motor clock signal, the FB motor clock signal, etc. is gradually lengthened and the rotation speeds of the conveyance motor 14 and the flat bed motor 32 of the automatic document feeder 3 are gradually reduced and finally stopped, The transport motor 14 and the flat bed motor 32 of the automatic document feeder 3
The synchronizing signal generator 64 generates a line valid signal at a cycle corresponding to the rotation speed of the main scanning synchronizing signal LSY.
Since NC and the generation period of the main scanning effective signal LGATE are adjusted, image data corresponding to the moving distances of the first and second traveling bodies 22 and 25 are output, and the video signal is correctly output to the external device 4. Can be included.

Similarly, when the PAUSE signal is no longer output from the external device 4, the controller 45 starts the generation of the motor clock signal, the main scanning synchronizing signal LSYNC ', the main scanning valid signal LGATE', etc. Of the DF motor clock signal and the FB motor clock signal are gradually shortened to gradually reduce the rotation speed of the carry motor 14 and the flat bed motor 32 of the automatic document feeder 3. When the rotational speed is raised to finally reach the normal rotational speed, the line enable signal is generated by the synchronization signal generator 64 at a cycle corresponding to the rotational speeds of the transport motor 14 and the flat bed motor 32 of the automatic document feeder 3. , The main scanning synchronization signal LSYNC,
Since the generation period of the main scanning effective signal LGATE is adjusted, it is possible to output the image data according to the moving distance of the first and second traveling bodies 22 and 25 so that the external device 4 correctly captures the video signal. You can

As described above, in this embodiment, the signal (PAUS) for interrupting / resuming the transfer of the video signal from the external device 4 is used.
When the E signal) is output, the video signal transferred to the external device 4 is interrupted and restarted by the scanner control unit 33, so that it has a second type interface that transfers image data unilaterally. Even when the image reading device 1 is incorporated into a digital copying machine or the like, the image data can be correctly transferred from the image reading device 1 to the external device 4 such as a host computer device without using a large capacity buffer memory circuit. The image reading device 1 can be made to function as a scanner of a host computer device or the like. Further, in this embodiment, as shown in FIG. 8, basically, a PAUSE signal is added to the current interface signal, and the configuration of the current interface signal is not significantly changed (while maintaining compatibility). Since the transfer of the video signal is temporarily stopped, the scanner function can be realized without using a large capacity buffer memory circuit even when the image reading apparatus 1 is incorporated in a digital copying machine or the like. In addition, in this form example, the transfer of the video signal is temporarily
When the scanning operation is stopped, the scanning operation is smoothly suspended / restarted by the scanner control unit 33. Therefore, even when the scanning operation is suspended / restarted, the image distortion is prevented from occurring and the digital copying machine is operated. In such a system, the scanner function can be realized without using a large capacity buffer memory circuit.

[0029]

As described above, according to the present invention, in the first aspect, the image data is transmitted in the system such as the digital copying machine by generating the signal for suspending / resuming the transfer of the image data in the interface. Even if the second type interface for unilaterally transferring to the external device is used, the scanner function can be realized without using a large capacity buffer memory circuit. In claim 2,
It is possible to temporarily stop the transfer of image data without significantly changing the current interface signal configuration (while maintaining compatibility), which allows a large-capacity buffer memory circuit in a system such as a digital copying machine. The scanner function can be realized without using. According to the present invention, when the transfer of the image data is once stopped, the reading operation is smoothly interrupted / restarted so that image distortion is not generated even when the reading operation is interrupted / restarted, and digital copying is performed. In a system such as a machine, without using a large capacity buffer memory circuit,
The scanner function can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of an embodiment of an image reading apparatus according to the present invention.

FIG. 2 is a block diagram showing a circuit configuration example of the image reading apparatus shown in FIG.

3A, 3B, 3C, and 3D are waveform timing charts showing an operation example when a PAUSE signal is input to the image reading apparatus shown in FIG.

FIG. 4 is a block diagram showing a detailed configuration example of a synchronization signal generation section provided in the third SIP circuit shown in FIG.

5 (a) to (i) are timing charts showing an operation example of the synchronization signal generating section shown in FIG.

6 (a), (b) and (c) are timing charts showing an example of the relationship between a sub-scanning synchronization signal, a sub-scanning valid signal, and valid image data in the image reading apparatus shown in FIG.

7 (a), (b) and (c) are timing charts showing an example of a relationship between a main scanning synchronization signal, a main scanning effective signal and effective image data in the image reading apparatus shown in FIG.

FIG. 8 is a table showing an example of interface signals of the image reading apparatus shown in FIG.

[Explanation of symbols]

1 image reading device, 2 document reading device, 3 automatic document feeding device, 4 external device, 5 device housing, 6 document tray, 7 pickup roller, 8 registration roller pair,
9 conveyance drum, 10 conveyance rollers, 11 paper ejection tray, 12 paper ejection guide path, 13 paper ejection roller pair, 14 paper feed motor, 15 paper size sensor, 16 feed sensor, 17 registration sensor, 18 feed clutch, 19 lamp regulator, 20 device housing, 21
Contact glass, 22 First traveling body, 23 Illumination lamp, 24 First mirror, 25 Second traveling body, 26 Second mirror, 27 Third mirror, 28 Lens, 29 Sensor block unit, 30 Pulley, 31 Driving belt, 32 Flatbed motor, 33 Scanner control unit, 34 Image processing unit, 35 Power supply unit, 36 Pressure plate open detection sensor, 37 Paper size sensor, 38 Home position sensor, 39 CCD, 40 Analog ASI
C circuit, 41 A / D converter circuit, 42 G / A circuit, 43 CPU bus, 44 IEP circuit, 45 control unit, 46 image processing unit, 47 driver unit, 48 CP
U circuit, 49 SRAM circuit, 50 EPROM circuit,
51 EEPROM circuit, 52 external input / output circuit, 53
DF motor driver circuit, 54 FB motor driver circuit, 55 third SIP circuit, 56 SEL circuit, 57
RS422 driver circuit, 58 counter circuit, 59
Register circuit, 60 comparison circuit, 61 line effective signal generation circuit, 62, 63 AND gate circuit, 65 connector

Claims (3)

[Claims] 1. A main-scanning valid signal LGATE and a sub-scanning valid signal F are read while reading an image of a document to be read.
In an image reading device that transfers a specified bit component of the image data VDT0-7 obtained by the reading operation to an external device together with GATE and the image data transfer clock signal VCLK, a suspend / resume signal (PAUSE signal) from the external device. ) Is output, the image reading operation of the original and the image data transfer operation are suspended / restarted. 2. The image reading apparatus according to claim 1, wherein the reading operation is interrupted when the interruption / resume signal output from the external device instructs the interruption of the image reading, and the sub-scanning valid signal FGATE is activated. In this state, the main scanning enable signal LGATE is made inactive to interrupt the transfer of the designated bit component of the image data VDT0-7, and the image reading restart is instructed by the suspend / resume signal output from the external device. Then, the reading operation is restarted, the main-scanning valid signal LGATE is made active while the sub-scanning valid signal FGATE is made active, and the image data VDT0 obtained by the reading operation together with the image data transfer clock signal VCLK. An image reading device characterized by restarting the transfer of the designated bit component of -7. . 3. The image reading device according to claim 1, wherein when the image reading interruption is instructed by an interruption / restart signal output from the external device, the reading speed in the sub-scanning direction is gradually increased. And the period of the main scanning effective signal LGATE output at a predetermined period is gradually lengthened,
The output of the main scanning enable signal LGATE is stopped after a predetermined time, and when the image reading restart is instructed by the suspend / resume signal output from the external device, the reading speed in the sub scanning direction is gradually increased and stopped. The main scanning effective signal LGATE that has been output is restarted, the cycle is gradually shortened, and after a predetermined time, the main scanning effective signal LG having a predetermined cycle.
An image reading device characterized by being ATE.