JP2007074643A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading apparatus which is capable of improving the development efficiency of hardware and software of a control board, and reducing a total development cost. <P>SOLUTION: A first control means 1501 is installed in a specific unit 1001, a second control means 1003 is installed in a matching unit 1002, and a memory means 1004 that is nonvolatile is installed to which a writing can be performed by the first control means. The matching unit comprises a reference clock generating means 1006 whose oscillation frequency can be changed, a data reading means which is configured so as to read out data that is read out from the memory means at arbitrary thinning rate, and a motor clock generation means which generates a motor clock for driving an optical motor by a combination of a frequency of the reference clock outputted from the reference clock generating means and the thinning rate set in the data reading means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, and more particularly to a control board thereof.

  An image reading apparatus incorporated in a conventional copying machine has a relatively simple configuration as compared with an image forming unit of the copying machine. Therefore, integration of control boards has progressed, and the control unit has one control board. It consists of This is largely due to the fact that image processing units, which are becoming more sophisticated year by year, are integrated on one chip, and the number of parts can be greatly reduced.

  By the way, the image reading apparatus has a configuration in which a reading unit is driven by an optical motor using a line image sensor typified by a CCD by a reduction optical system, and a desired original is read by sequentially reading line images. Most are things.

  Therefore, the specifications of the control unit that controls the mechanical operation other than the image processing are such that the driving speed for driving the reading unit is different for each product, and there is no great difference from the low speed machine to the high speed machine.

  On the other hand, in such an image reading apparatus, an automatic document feeder (hereinafter referred to as ADF) capable of automatically conveying a plurality of originals one by one to the image reading unit of the image reading apparatus and sequentially reading the original images. ) Is usually standard or optional. Such an ADF requires a mechanical structure that realizes complicated paper conveyance. A model connected to a high-speed image reading device distributes a driving load to convey a document at high speed, and is a stepping source that is a driving source. The number of motors is usually larger than that of low speed machines. Further, since accuracy is required for the document conveyance timing, the number of sensors for detecting the position of the document is also increased compared to the low-speed machine.

  Therefore, the ADF installed in a low-speed machine with a small number of stepping motors and sensors controls the ADF by the control unit of the image reading device directly outputting the driving clock of the stepping motor or inputting the sensor output of the ADF. It was possible to do. However, the ADF installed in a high-speed machine has a heavy control load, and it is difficult for the control unit of the image reading apparatus to directly control. Therefore, a control unit for controlling these loads is also provided in the ADF, and the control unit of the image reading apparatus and the control unit of the ADF communicate with each other to adjust the timing and perform image reading using the ADF.

(Outline of operation of image reading apparatus)
First, an outline of the operation of the image reading apparatus that reads one sheet original will be described with reference to the drawings.

  As shown in FIG. 18, the image of the original 1204 placed on the original platen glass 1203 illuminated by the original illumination lamp 1201 is colored through the first mirror 1205, the second mirror 1206, the third mirror 1207, and the lens 1208. The image is formed on the CCD 1209 and the line image of the original 1204 is read. A reading unit 1210 including a document illumination lamp 1201 and a first mirror 1205 moves in the direction of arrow A, and sequentially reads line images. At this time, the second mirror 1206 and the third mirror 1207 also move in the direction of arrow A, and are driven by a drive system (not shown) so that the distance (optical path length) from the document surface to the color CCD 1209 is constant.

A sequence in which the document image of the document 1204 is actually read with the configuration of FIG. 18 will be described.
When an original reading command is input by an operator (specifically, a copy button is pressed), the optical system 1R drives the reading unit 1210 from the arrangement shown in FIG. The reading position is arranged directly below the shading correction plate 1211 by moving in the direction of the arrow B by the system. Next, the optical system 1R turns on the original illumination lamp 1201, illuminates the shading correction plate 1211, and guides the line image of the shading correction plate 1211 to the color CCD 1209 via the mirror 1205, mirror 1206, mirror 1207, and lens 1208.
The output signal for each pixel of the line image of the shading correction plate 1211 read by the color CCD 1209 is corrected by an image processing circuit (not shown) so that the output level of all the pixels becomes a predetermined level. By this image processing, unevenness in illuminance of the document illumination lamp 1201, a decrease in the amount of light around the lens 1208, and unevenness in sensitivity for each pixel of the color CCD 1209 are corrected, and unevenness in reading the document image is corrected.

  When the shading correction process is completed, the reading unit 1210 is further moved in the direction of arrow B by a drive system (not shown), and is disposed immediately below the flow reading window 1212 (the flow reading window 1212 will be described later).

  Immediately below the flow reading window 1212 is a document image reading start position. From this position, the drive system (not shown) accelerates the reading unit in the direction of arrow A, and the reading position is pressed by the pressure plate 1213 to obtain flatness. Control is performed so as to be driven at a constant speed at a predetermined speed until the leading end of the maintained original 1204 is reached.

  When the reading position of the reading unit 1210 reaches the leading end of the original 1204, the color CCD 1209 starts reading line images of the original 1204 sequentially.

A driving system (not shown) moves the reading unit 1210 in the direction of arrow A while maintaining a constant speed, stops reading after reaching the end of the original 1204, stops driving, moves the reading unit 1210 in the direction of arrow B, The arrangement shown in FIG. 18, that is, the home position is returned, and a series of image reading is finished, and it waits for the next reading.
This is the end of the description of the basic image reading operation for reading a sheet original by the image reading apparatus.

  Next, an outline of the operation of the image reading apparatus equipped with an auto document feeder (ADF) will be described. The ADF has a function of automatically and continuously exchanging a large number of documents, so that it is possible to save the trouble of replacing each document one by one and shorten the copying time.

  A reading operation using the ADF will be described with reference to FIG. In the image reading apparatus in which the ADF 1300 is replaced with the pressure plate 1213 in FIG. 18 and the reading unit 1210 is positioned at the home position (that is, the position in FIG. 18), an operator inputs a document reading command. (For example, press the copy button). Then, the drive system (not shown) and the image processing circuit (not shown) perform the shading correction described in the description of FIG. 18, move each member so as to have the member arrangement of FIG. 19, and position the reading unit 1210. Fix it. This position corresponds to the same position as the start position described in FIG. A start reading window 1212 is provided at the start position. In the case of ADF reading, a plurality of originals are placed on the paper feed tray 1301. When reading is started, the original is fed one by one by the feed rollers 1302 and 1303, and passes through the slits of the guides 1304, 1307, 1306 and the transport roller 1305 by the transport roller 1305 rotating in the direction of the arrow, and then the paper discharge tray. It is discharged to 1308.

  The rotation speed of the conveying roller 1305 is determined by the reading magnification. The document conveyed by the conveyance roller 1305 is read by the reading unit 1210 from the flow reading window 1212.

  As described above, the line image data of the original read by the configuration of FIG. 18 or FIG. 19 is sequentially sent to the image output unit (not shown), and the read image is formed by the image output unit.

(Control circuit of image reading apparatus)
Next, a control circuit of a conventional image reading apparatus will be described with reference to the drawings.
FIG. 20 is a control board block diagram of an image reading apparatus having a relatively low reading speed. The control board block diagram of the image reading apparatus, which has a relatively high reading speed, will be described later. However, there is a difference in the operation outline described above both when reading a sheet original and when reading a plurality of originals using ADF. I will refuse here.

(Description of low-speed image reader)
In the image reading apparatus 1500, a CPU 1501 that executes system control on a control board 1517, a ROM 1502 that stores a control algorithm of the CPU 1501, and a RAM 1503 that develops data of the CPU 1501 are connected by a system bus 1504. The CPU 1501 reads a program stored in the ROM 1502 and performs system control while using the RAM 1503 as a work area as appropriate. An image processing ASIC 1505 that processes image data of a document image read by the image reading device 1500 is also connected to the system bus 1504. The CPU 1501 performs data setting on a register configured in the image processing ASIC 1505 as necessary, and reads / writes the contents of the memory configured in the ASIC 1505.

  The image processing ASIC 1505 is connected to a CCD substrate 1514 on which a color CCD 1515 for reading a line image of an original image is mounted. Image data output from the CCD substrate 1514 is input to the ASIC 1505, subjected to predetermined image processing, and sent to an image forming unit (not shown) configured outside via an I / F circuit 1516. The

A motor driver 1506 is connected to the CPU 1501, and a frequency clock corresponding to the rotation speed required for the optical motor 1507 is sent from the CPU 1501, and the motor driver 1506 generates a motor drive pulse corresponding to the input clock. The optical motor 1507 is driven to rotate in accordance with the drive pulse.
The optical motor 1507 is controlled to drive the image reading unit 1210 shown in FIG. 18 by a drive system (not shown) and sequentially read line images of the original image by the color CCD 1515. Details of the drive control will be described later.

  Further, an inverter 1508 is connected to the CPU 1501, and when an ON signal is input from the CPU 1501, the lamp 1509 is turned on via the inverter 1508. The lighting timing is synchronized with the image reading timing of the image reading device 1500. That is, it is synchronized with the start timing of the optical motor 1507.

  Further, a home position sensor 1510 is connected to the CPU 1501, and a signal from the home position sensor 1510 is input to detect whether an image reading unit (not shown) is located at the home position.

Furthermore, document size detection sensors 1511-1 and 1511-2 are connected to the CPU 1501, and signals from the document size detection sensors 1511-1 and 1511-2 are input and placed on a document placement table (not shown). The size of the printed document is detected.
Further, an ADF 1513 is connected to the CPU 1501 via an I / F circuit 1512. The ADF 1513 is equipped with a transport motor 1518 for transporting the document and a read motor 1519 for transporting the document to the reading position.

  Two motor drivers (not shown) having the same function as the motor driver 1506 are provided in the ADF 1513, and the transport motor 1518 and the read motor 1519 are driven by the same control as the optical motor 1507. Therefore, the CPU 1501 bears the control load for driving the optical motor 1507 by three motors.

  Also, in the ADF 1513, a registration sensor 1520 for detecting the registration position for performing registration adjustment for canceling skew of the leading end of the conveyed document, and a lead for detecting that the conveyed document is at the reading position. A sensor 1521 and a paper discharge sensor 1522 for detecting that the conveyed document is at a paper discharge position are provided. These sensors are used for document conveyance drive timing and jam detection in the ADF 1513, but the control load of the home position sensor 1510 is the same in that a sensor signal is input to the CPU 1506. Therefore, the CPU 1501 is responsible for four control loads for detecting the signal of the home position sensor 1510.

(Optical motor drive)
The driving of the optical motor in the image reading apparatus having such a configuration will be described.
When the minimum reduction ratio required for the image reading apparatus 1500 is 50%, the drive profile is as shown in FIG. In the document image reading drive profile of FIG. 21, the horizontal axis indicates time, and the vertical axis indicates the driving speed of a reading unit (not shown).
This will be described with reference to the diagram of the member configuration shown in FIG.
That is, at time t0, the reading unit disposed at the reading start position (in FIG. 12, the reading unit 1210 is disposed immediately below the flow reading window 1212) starts the optical motor and starts driving at a speed of 7 mm / s. To do.
Thereafter, acceleration is continued at the acceleration α until time t1, and control is performed so that constant speed driving is performed at a speed of 200 mm / s, which is a reading speed of 50% at time t1 (at this time, in FIG. 18, the reading unit 1210 is controlled. It is arranged immediately below the front end of the original 1204).
From this point, reading of the original is started, and line images of the original are sequentially read at a reading speed of 200 mm / s.

At time t2, reading of the document ends (at this time, the reading unit 1210 is disposed immediately below the end of the document 1204 in FIG. 18).
At time t2, the driving speed of the reading unit is decelerated at a deceleration β, and when it is decelerated to a speed of 7 mm / s at time t3, the driving is stopped.

  Thereafter, the driving is stopped for a time period until time t4. At time t4, the driving is started at a starting speed of 7 mm / s in the direction opposite to the reading direction, accelerated at an acceleration α, and at a speed of 200 mm / s at time t5. The back scan operation is performed under the control of constant speed driving. From time t5 to time t6, constant speed driving is performed at 200 mm / s, and deceleration is started at a deceleration β from time t6, and activation is stopped when the speed is 7 mm / s at time t7.

Since the number of motor clocks sent from time t0 to t3 and the number of motor clocks sent from time t4 to t7 are set to be the same, at time t7, the reading unit 1210 in FIG. It is arranged directly below 1212.
Thereafter, the reading unit 1210 returns to the home position according to the home position return sequence.

(Generation of motor clock)
The generation of a specific motor clock (clock sent from the CPU 1501 in FIG. 20 to the motor driver 1506) will be described.
As for the motor clock, the CPU 1501 in FIG. 22A reads the drive data stored in the ROM 1502 ((1) in FIG. 22A), and the speed table shown in FIG. The data is expanded in the RAM 1503 ((2) in FIG. 22A). The CPU 1501 sequentially reads the cycle for each clock from the speed table developed in the RAM 1503 ((3) in FIG. 22A) and generates a motor clock.

  Specifically, the drive data shown in FIGS. 22A and 22A is read with period data corresponding to the acceleration start speed and the deceleration end speed (t0, t3, t4, and t7 in FIG. 21) and Data corresponding to the speed and the speed of the back scan speed (t1, t5 in FIG. 21) is read as a parameter. Since the acceleration section, that is, the distance from t0 to t1 in FIG. 21 is determined by the configuration of the image reading apparatus, the number of clocks sent between t0 and t1 is uniquely determined by the movement distance of one motor clock. Here, since the acceleration section is 30 mm and the movement distance of one motor clock is 0.2 mm, the movement is 30 mm with 150 shots regardless of the frequency of the motor clock.

  The contents of the speed table shown in FIG. 22 (a), (2) or (3) are as shown in FIG. 22 (b). FIG. 22B shows only the acceleration section of FIG. 21, that is, the table from t0 to t1. For example, when the optical motor is activated, the value of address 0000d is read to obtain data 12000d. The CPU 1501 counts the clocks of the system clock input from the oscillator 1701, and generates 1 motor clock from the port P of the CPU 1501 when it reaches 12000.

  The generated motor clock is also input to the interrupt terminal INT of the CPU 1501. When an interrupt is input to the CPU 1501, the CPU 1501 reads the data at the address 0001d in the speed table, and generates one motor clock when the count reaches 11500. Thus, the motor clock is sequentially generated to accelerate the optical motor.

  When the CPU 1501 reads the data at address 0150d and counts 30, the reading unit moves a distance of 30 mm, and from there moves at a constant speed of 200 mm / s, and reading of the document is started. The count 30 is a process corresponding to a 200 mm / s movement of the reading unit. The speed table data until the reading is completed is 30, and the control at the time of deceleration is performed similarly to the control at the time of acceleration. A description of the control is omitted.

Such a method is generally known as the prior art. For example, in Patent Document 1, an example of a configuration as shown in FIG. 23 is clearly shown.
The configuration of FIG. 23 will be described.
FIG. 23 is a block diagram showing the configuration of the printer apparatus.
The CPU 1 is interrupted by a timer, and outputs motor control data to the motor control port based on the pulse width data stored in advance in the RAM 2 when the interrupt is accepted. Each time there is a timer interrupt, the trapezoidal pulse width data stored in advance in the RAM 2 is sequentially transferred, that is, the pulse width data to the carriage motor (X motor) for moving the carriage to the print start position, and then the head is lowered. The pulse width data to the head motor (RH motor) for printing, the pulse width data to the Y motor for printing, and the respective driving data are sequentially sent in time series.
The disclosure of Patent Document 1 is a technique related to motor driving of a printer, but the motor driving of the image reading apparatus is not much different.
That is, if the constant speed section is 420 mm for A3 size and the deceleration section is 20 mm, the total moving distance is 470 mm, so a speed table composed of 2100 pieces of data is required.

  Of course, the data obtained from FIGS. 22 (a) and (2) may be the speed table itself, but data for each clock is required, and the amount of data to be developed in the speed table becomes enormous, and the CPU 1501 has a speed table. Since it takes a lot of time to expand the table, there is a demerit that the load becomes heavy.

  Furthermore, in Patent Document 2, an oscillator that outputs a clock having a predetermined frequency, a division period that divides the clock output from the oscillator, and a clock of the sub-scanning motor are generated from the clock divided by this division period. A control device and control method for a sub-scanning motor using a clock generator have been proposed. However, simply dividing the clock only changes the motor drive speed, and the position of the image leading edge from the start position of the reading unit. It was not possible to cope with the change of distance.

(ADF control)
In FIG. 20, the ADF 1513 is driven by the CPU 1501. The ADF 1513 is provided with a transport motor 1518 and a read motor 1519. From the viewpoint of motor control, each motor control is not much different from the control of the optical motor described above.
When reading an original using the ADF, the optical motor is fixed, so that the control load on the CPU 1501 related to motor control is about two motors.
The ADF 1513 and the CPU 1501 are provided with communication signals in addition to the connection of the two motor clocks and the three sensor signal connections of the registration sensor, the lead sensor, and the sheet discharge sensor. Exchanges information without accompanying it.

(Description of high-speed image reader)
Next, the configuration of the high-speed image reading apparatus will be described.
FIG. 24 is a control circuit block diagram of the high-speed image reading apparatus.
Members having the same functions as those of the low-speed image reading apparatus of FIG.
Therefore, the control block diagram is not much different from that of the low-speed image reading apparatus. The difference is that the speed table of the optical motor 1507 is different in order to read the image at high speed, and the slave CPU 1801 is between the CPU 1501 and the interface circuit 1512 of the ADF. It is the inserted point.

The speed table of the optical motor 1507 is developed as shown in FIG. Compared to FIG. 20, the acceleration increases from α to α2 and the deceleration increases from β to β2, indicating that the reading speed is doubled from 200 mm / s to 400 mm / s.
However, since the optical frame of the image reading apparatus is assumed to be diverted, the optical frame itself is not changed. Therefore, the restrictions on the acceleration zone 30 mm and the deceleration zone 20 mm are the same.

  On the other hand, the ADF has a separation motor 1804 that separates a plurality of documents one by one and a separation motor that sandwiches the conveyed documents as necessary and suppresses the movement of the documents in order to disperse the driving load for the purpose of high-speed reading. 1805 is added, and driving is realized by a total of four motors. Furthermore, since it is necessary to monitor the behavior of the conveyed document in detail, a separation sensor 1806 for detecting the separated document is added.

  If such a configuration is adopted and all the control is executed only by the CPU 1501, the sequence for reading a series of images must be controlled in parallel, so that the control load becomes too heavy. CPU resources for driving individual motors are also insufficient. Accordingly, since it becomes impossible for the CPU 1501 to directly drive the four motors of the ADF 1813 as in the low-speed image reading apparatus, the CPU 1803 is also provided on the ADF 1813 side, and is configured to perform control dedicated to the ADF. In order to grasp the control management of the two CPUs 1501 and 1803 from each other, two communication dedicated CPUs, slave CPUs 1801 and 1802 are configured. Therefore, the CPU 1501 only needs to communicate with the slave CPU 1801 with respect to the ADF 1813, and does not need to send a motor clock unlike the low-speed image reading apparatus.

  The slave CPU 1802 transfers the control command received from the slave CPU 1801 to the CPU 1803, and the CPU 1803 performs overall control of the ADF 1813 and transmits the control state to the CPU 1501 via the slave CPU 1802 and slave CPU 1801.

(Other control)
Control of lighting of the lamp 1509 via the inverter 1508, input of sense signals of the home position 1510 and document size detection sensors 1511-1 and 1511-2, and control of the image processing ASIC 1505 are substantially the same as those of the low-speed image reading apparatus. .
Japanese Patent Laid-Open No. 5-104808 JP-A-9-65696

  However, since the latest image processing IC is developed for each product development in the control board of the image reading apparatus constituted by one sheet as described above, it is necessary to newly design the control board for each product development. there were.

  As for the software for controlling the control board, the control specification for controlling the mechanical operation other than the image processing is changed only for the drive speed specification for driving the reading unit for each product and the control of the image processing IC described above, In other parts, the design philosophy is used and a program according to the product specifications is set up. However, when considered as a total program, it must be handled as a different program for each product, and it took time for software development, and it was necessary to pay close attention to management.

  Furthermore, the control specifications of the ADF differ between the low-speed image reading device and the high-speed image reading device, and it is necessary to design them separately. This also remakes the hardware and software of the control board of the image reading device for each product. It is the cause.

  For this reason, an individual development cost is generated for each product and a development period is required. This increases the cost of the control board of the image reading apparatus for each product and hinders the shortening of the development period.

  Furthermore, since the speed table for driving the motor is linear acceleration with constant acceleration to reduce the program capacity and CPU load, the acceleration becomes zero at once when shifting from acceleration to constant speed. The reading unit may vibrate and the read image at the leading edge of the document image may be blurred, and since the motor is accelerated at the time of starting the motor, the start-up sound is loud and the user may feel uncomfortable.

  The present invention has been made under such circumstances, and provides an image reading apparatus capable of improving the development efficiency of hardware and software related to a control board and reducing the total development cost. This is a problem.

  In order to solve the above-described problem, in the present invention, an image reading apparatus is configured as described in (1) below.

(1) an image reading unit that is driven by an optical motor and reads a document placed on a document table by a line sensor;
It is composed of at least two substrates of a specific unit and an alignment unit, a first control unit is mounted on the specific unit, a second control unit is mounted on the alignment unit, and a drive table for the optical motor is further provided. Non-volatile storage means that stores data for determination and is writable by the first control means is mounted, and the specific unit and the alignment unit are connected by a predetermined interface that does not depend on the specifications of the image reading apparatus A control unit,
With
The matching unit includes a reference clock generating unit having a variable oscillation frequency, a data reading unit configured to read data read from the storage unit at an arbitrary decimation rate, and a reference clock output from the reference clock generating unit. Motor clock generating means for generating a motor clock for driving the optical motor by a combination of a frequency and a thinning rate set in the data reading means;
An image reading apparatus.

  According to the present invention, the specific unit may be used for each product as it is, and the specific unit may be newly designed. In addition, since the specific unit to be newly designed is designed with a predetermined interface as an interface with the matching unit, the design philosophy can be easily used, and the design period and the development period can be shortened. Therefore, the development efficiency can be improved and the total development cost can be reduced.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to an embodiment of an image forming apparatus.

FIG. 2 is a cross-sectional view of an essential part of the “image forming apparatus (copier)” according to the first embodiment.
The image forming apparatus of the present embodiment is an electrophotographic system, reads an image of a document with an image reading device 1R, and forms an image on a transfer material P from image information from the image reading device 1R with an image output unit 1P. Further, the image output unit 1P will be described as a color image output device in which a plurality of image forming units considered to be particularly effective in the present invention are arranged in parallel and an intermediate transfer method is adopted.

The outline of the operation of the image reading apparatus 1R is the same as that described in the background art section.
Here, the control block diagram of the image reading apparatus will be mainly described.
FIG. 1 is a block diagram illustrating a configuration of a control system in the image reading apparatus used in this embodiment. One control board often seen in the conventional image reading apparatus is divided into a specific unit 1001 and an alignment unit 1002 by function.
The specific unit 1001 is a unit designed for each specification of the image reading apparatus, and the alignment unit 1002 is a unit that can be used in common regardless of the specifications of the image reading apparatus.
Hereinafter, the specific unit 1001 and the matching unit 1002 will be described in detail.

(Specific unit 1001)
In the image reading apparatus, a CPU 1501 that executes system control, a ROM 1502 that stores a control algorithm of the CPU 1501, and a RAM 1503 that develops data of the CPU 1501 are connected to a specific unit 1001 in the form of a substrate via a system bus 1504. The CPU 1501 reads a program stored in the ROM 1502 and performs system control while using the RAM 1503 as a work area as appropriate. Also connected to the system bus 1504 is an image processing ASIC 1505 for processing image data of a document image read by the image reading apparatus. The CPU 1501 performs data setting on a register configured in the image processing ASIC 1505 as necessary, and reads / writes the contents of the memory configured in the ASIC 1505.

  Connected to the image processing ASIC 1505 is a CCD substrate 1514 on which a color CCD 1515 for reading a line image of a document image is mounted. Image data output from the CCD substrate 1514 is input to the ASIC 1505, subjected to predetermined image processing, and sent to an image forming unit (not shown) configured outside via an I / F circuit 1516. The

The image forming unit (not shown) and the CPU 1501 communicate with each other via the ASIC 1505, execute the operation requested by the command from the image forming unit, return the status of the operation state, and execute the operation in cooperation with the image forming unit. ing.
In addition, parameters necessary for image processing may be acquired from the image forming unit and set in the ASIC 1505 as necessary.

A motor driver 1506 is connected to the CPU 1501, but a motor clock for driving the motor and a control signal for changing drive specifications (such as forward and reverse rotation of the motor) are obtained from the matching unit 1002 which takes the form of a board. Therefore, there is almost no control load on the drive system of the CPU 1501. The motor driver 1506 generates a motor drive pulse corresponding to the input clock, and the optical motor 1507 is rotationally driven according to the drive pulse.
The motor driver 1506 is selectively mounted according to the specification of the connected optical motor 1507, but the specification of the control signal including the motor clock is standardized.

  The optical motor 1507 is controlled by a drive system (not shown) to drive the image reading unit 1210 shown in FIG. 18 (the same configuration is used in this embodiment), and sequentially read line images of the original image by the color CCD 1515. Is done. Details of drive control in the matching unit 1002 will be described later.

  Further, an ADF 1013 is connected to the CPU 1501 via an I / F circuit 1512. The ADF 1013 sandwiches a transport motor 1518 for transporting a document, a read motor 1519 for transporting the document to a reading position, a separation motor 1804 for separating a plurality of documents one by one, and a document to be transported as necessary. A total of four motors, a separation motor 1805 that suppresses shaking, are mounted.

  Further, in the ADF 1013, a registration sensor 1520 for detecting the registration position for performing registration adjustment for canceling skew of the leading edge of the conveyed document, and a lead for detecting that the conveyed document is at the reading position. A total of four sensors are provided: a sensor 1521, a paper discharge sensor 1522 that detects that the conveyed original is at a paper output position, and a separation sensor 1806 that detects the separated original. These sensors are used for document conveyance drive timing and jam detection in the ADF 1013.

As described above, the load configuration of the ADF 1013 is not different from the load configuration of the ADF 1813 described with reference to FIG. 24, but the slave CPU 1802 and the CPU 1803 found in the configuration requirements of the ADF 1813 are not configured.
This is realized by reviewing the configuration because the control load is drastically reduced since the timing control related to the optical motor 1507, the lamp 1509, the home position sensor 1510, and the document size detection sensors 1511-1 and 1511-2 is no longer necessary for the CPU 1501. Has been.

An example of the connection between the CPU 1501 and the interface circuit 1512 is shown in FIG.
In FIG. 3, the conveyance motor clock, the read motor clock, the separation motor clock, and the separation motor clock are sent to the interface circuit 1512 to the ports P <b> 0 to P <b> 3 of the CPU 1501.
In addition, signals of the registration sensor, the read sensor, the paper discharge sensor, and the separation sensor are input to the interrupt terminal of the CPU 1501, and the control of each motor clock transmitted to the ports P0 to P3 is switched according to these interrupt inputs. Control.

When the ADF 1513 shown in FIG. 20 is connected to the specific unit 1001 having such an interface, the same interface is provided.
In this case, it is of course unnecessary to control the separated motor clock output from the port P3 and the separation sensor input input to the interrupt terminal INT3. However, since the program relating to the control of these signals may be deleted from the ROM 1502, the signal connection Therefore, it is not necessary to change the design of the interface circuit 1512. Therefore, it is possible to divert the hardware design regardless of the specifications of the image reading apparatus.

(Alignment unit 1002)
Returning to FIG. 1, the matching unit 1002 will be described.

  In the image reading apparatus, an ASIC 1003 that controls the alignment unit 1002 is configured on an alignment unit 1002 in the form of a substrate. An inverter 1508 is connected to the ASIC 1003, and when an ON signal is input from the ASIC 1003, the lamp 1509 is turned on via the inverter 1508. The lighting timing is synchronized with the image reading timing of the image reading apparatus. That is, it is synchronized with the start timing of the optical motor 1507.

  Further, a home position sensor 1510 is connected to the ASIC 1003, and a signal from the home position sensor 1510 is input to detect whether the image reading unit is located at the home position.

Furthermore, document size detection sensors 1511-1 and 1511-2 are connected to the ASIC 1003, and signals from the document size detection sensors 1511-1 and 1511-2 are input and placed on a document placement table (not shown). The size of the printed document is detected.
Further, the ASIC 1003 and the CPU 1501 on the specific unit 1001 are connected by a serial communication line 1007, and the ASIC 1003 performs system operation control according to the command from the CPU 1501, and this operation is controlled by the ADF 1013. Not included.

In addition, the system 150 is notified of the operation status of the system to the CPU 1501 via the serial communication line 1007.
Furthermore, communication with a specific unit is performed when the system is turned on, an identification ID assigned to the specific unit is received in advance, and a drive table of the optical motor 1507 corresponding to the identification ID is configured in the ASIC 1003 (not shown). Expand in the RAM area.
Reference numeral 1006 denotes an oscillation circuit which inputs a clock having an optimal frequency to the ASIC 1003 in accordance with the identification ID of the specific unit obtained when the system power is turned on.
This clock is processed into a motor clock inside the ASIC 1003 as a basic clock of a motor clock for driving the optical motor 1507. Detailed processing procedures will be described later.

Reference numeral 1004 denotes an EEPROM as an example of a configuration requirement of the nonvolatile memory.
The EEPROM 1004 stores data for performing drive control of the optical motor 1507. This data stores information related to a basic table for driving a predetermined optical motor, and this data does not depend on the specifications of the image reading apparatus, and the same data is stored uniformly.
The EEPROM 1004 is configured so that writing from the CPU 1501 can be performed by a writing line 1008, and therefore, the contents can be rewritten to correspond to a specific specification.

(Interface between specific unit and matching unit)
The specific unit 1001 and the matching unit 1002 are connected by interface circuits 1005-1 and 1005-2, respectively.
This interface specification is a predetermined specification irrespective of the specification of the image reading apparatus.
An example is shown in FIG.
In FIG. 4, SCLK, SDATA, and SLOAD are general signals for accessing the EEPROM 1004.
These signals are connected via the gate circuits 2101 to 2103 for writing from the CPU 1501 to the EEPROM 1004, while the signals for reading from the ASIC 1003 are also connected via the gate circuits 2101 to 2103.

The gate circuit is configured so that if either one of the signals is input, it is input to the EEPROM 1004 as it is, but the statuses of the communication lines Tx and Rx are exchanged so that the timing of writing and reading does not overlap. In addition, only one of the accesses is controlled to be valid.
In addition, as described above, the CPU 1501 and the ASIC 1003 exchange statuses with each other using the communication signals Tx and Rx.
Signals MCLK, Vref, R / L, and RST are input from the ASIC 1003 to the motor driver 1506.

  MCLK is a basic clock for driving the optical motor 1507, Vref is an analog voltage value for controlling the drive current of the optical motor 1507, R / L is a logic signal for determining the rotation direction of the motor 1507, and RST is a motor as required. This signal resets the internal logic of the driver 1506.

(Optical motor drive control)
Hereinafter, drive control of the optical motor will be described.

FIG. 5 is a block diagram in which a configuration relating to optical motor driving is extracted. Of course, the configuration of FIG. 5 is configured on the matching unit 1002 (FIG. 1).
FIG. 5 is a block diagram of an MCLK generation circuit that is a motor clock. Blocks other than the EEPROM 1004 and the oscillation circuit 1006 are configured in the ASIC 1003.

In FIG. 5, reference numeral 2207 denotes a serial-to-parallel converter, which converts serial data output from the EEPROM 1004 into 16-bit parallel data. The EEPROM 1004 stores motor clock frequency data of the acceleration section and the deceleration section of the optical motor. The 16-bit parallel data converted by the serial-parallel converter is stored in the RAM 2202. At this time, the address control unit 2201 generates an address corresponding to the identification ID of a specific unit (not shown) obtained by the initial communication by the matching unit 1002. That is, since the distance from the start position of the image reading unit (not shown) to the leading edge of the document is assigned in advance by the identification ID, for example, in the case of acceleration section data, addresses corresponding to the number of clocks necessary for the acceleration section It is controlled to write data to This data is frequency data for each motor clock.
For example, assuming that 100 pieces of data for the acceleration section are stored in the EEPROM 1004 and the number of clocks necessary for the acceleration section determined by the identification ID is 85, the address control unit 2201 reads from the 100 pieces of data read from the EEPROM 1004. Then, 15 data are thinned out at equal intervals, and 85 data is written to the RAM 2202 via the serial-parallel converter 2207.
The same applies to the deceleration section. For example, assuming that the number of clocks required for the deceleration section is 70, 30 data are thinned out at equal intervals from 100 data read from the EEPROM 1004, and 70 data are serialized. Control to write to the RAM 2202 via the conversion unit 2207 is performed.
However, this method is one method for realizing the object, and is not a control essential to the realization of the present invention. For example, when reading the EEPROM 1004, the data to be read is thinned out, and all the read data are read out. You may control to write in RAM2202.

  Clocks for reading data from the EEPROM 1004, address generation by the address control unit, and writing to the RAM 2202 are supplied from the clock generation unit 2205. The written data is read from the RAM 2202, transferred to the data expansion unit 2203, and expanded into a pattern corresponding to the input data. The developed pattern is transferred to the shift register 2204, and the shift register 2204 loads data at the rising timing of the output motor clock MCLK. The loaded data is swept out bit by bit by a fixed period clock from the clock generator 2205 and output from the ASIC 1003 as the motor clock MCLK.

A timing chart of the RAM 2202, the data expansion unit 2203, and the shift register 2204 will be described with reference to FIG.
FIG. 6 shows that the high period of the motor clock at the start of acceleration is for 600 basic clocks. In the data development unit 2203, the development is performed assuming that the motor clock has 600 high intervals and the low interval 600, that is, the first one of the motor clock has a period of 1200 basic clocks.
Since the next read data is 575, the motor clock in the acceleration section is developed in the same manner as a motor clock having a period corresponding to the high section 575, the low section 575, and the total basic clock 1150.
Since the data at the end of the acceleration is 006, the data to be read next becomes 000 when the motor clock having the cycle of 6 high intervals, 6 low intervals, and 12 basic clocks has been developed.
The data “000” indicates the previous data, that is, a code indicating that 006 is a constant-speed motor clock. Although it is 000 here, it may be 999 as long as it is a predetermined numerical value.
When the data 000 is read, reading from the RAM 2202 is interrupted, and development of the motor clock in the constant speed section is started.
For example, if the identification ID of an image reading apparatus that performs reading of 420 mm is recognized, the development for 12 basic clocks is repeated by the number of clocks corresponding to 420 mm.
When the development of the constant speed section is completed, the data reading from the RAM 2202 is resumed, and the data reading of the deceleration section is started.
It goes without saying that the first data in the deceleration zone is the same as the data in the constant velocity zone at the same time as the data at the end of the acceleration zone.
In other words, after the data 006 is read, the data is sequentially read from the RAM 2202 as in the acceleration section, and the cycle of each motor clock is developed by the data development unit 2203. When the expansion of the deceleration zone is completed, data 000 is read from the RAM 2202.
When the data 000 is read, it means that all the motor drive profiles have been developed, and the motor drive profile is completed.

Returning to FIG.
In the shift register 2204 of FIG. 5, data for one motor clock is read from the data developed by the data development unit 2203, and shift registration is sequentially performed bit by bit.
As shown in FIG. 6, the shift direction sequentially shift-registers from one continuous data.
Each time one motor clock MCLK is output, data for the next one motor clock is read into the shift register 2204, and shift registration is performed bit by bit.
The waveform of the motor clock MCLK generated by the method described above is shown in comparison with the motor drive profile.
FIG. 7 shows a motor drive profile obtained by the method described so far. A timing chart showing the relationship between the point clock A, the shift clock input to the shift register at the point B, and the motor clock MCLK is shown in the lower part.
At point A, activation of the optical motor 1507 is started. Before point A, the motor clock MCLK is not generated. At point A, the first motor clock MCLK is output, but it can be seen that one motor clock MCLK is output with the shift clock 1200 as shown.
Since point B is a point at which the optical motor 1507 is rotating at a constant speed, it can be seen that one motor clock MCLK is output by 12 shift clocks, and this is continuously generated.

In FIG. 5, the oscillation circuit 1006 generates a reference clock at an optimal oscillation frequency in accordance with the setting of the frequency setting unit 2206. Ideally, it is desirable that an analog stepless frequency can be set, but a configuration capable of generating an optimum multiplied frequency may be used.
By combining the frequency of the basic clock output from the oscillation circuit 1006 and the setting of the number of shift clocks per motor clock MCLK stored in the EEPROM 1004, a desired optical motor drive profile that is uniquely determined from the identification ID can be obtained. You can do that.
For example, when an identification ID for setting a reading sequence faster than the drive profile obtained in FIG. 7 is recognized, the setting of the oscillation circuit 1006 is changed so that a higher frequency basic clock is generated. That's fine.

By the way, the optical motor drive profile obtained in FIG. 7 is set so that the sections L1 and L3 have nonlinear acceleration curves and the section L2 has linear acceleration curves. The section L4 is a constant speed section, the sections L5 and L7 have a non-linear deceleration curve, and the section L6 is set to have a linear deceleration curve.
The fact that this setting can be made freely is a major feature of this embodiment.
As in the prior art, when the acceleration section and the deceleration section are linearly set, if the speed setting at the time of startup is relatively high, the startup sound is loud and uncomfortable for the user.
Also, when the speed setting at startup is relatively low, the startup sound can be reduced, but since the speed at startup is set low, a sharp acceleration curve is required to increase the rotational speed to the desired constant speed. The instantaneous reading unit that has shifted to a constant speed vibrates, and the image leading end may be shaken during image reading.
In order to solve both the start-up sound problem and the image blurring problem, trial and error were required to optimize each setting.

For this purpose, the motor clocks in the acceleration section and the deceleration section may be set non-linearly as shown in FIG. 7, but the program needs to have a cycle for each clock and the program capacity is enormous. In this embodiment, the data related to the speed profile of the acceleration section and the deceleration section is configured to generate a clock for one period with data for a half period of the clock. The clock is configured not to require the data capacity of the constant speed section by repeatedly using the final data of the acceleration section.
For this reason, it is possible to minimize the program capacity for creating the speed profile (specifically, the capacity of the EEPROM 1004).

By implementing the configuration as described above, the drive profile in the acceleration section and the deceleration section is appropriately stored in the EEPROM 1004, and the optimum transmission frequency is set in the oscillation circuit 1006, thereby reducing the startup sound with a small program capacity. Thus, it is possible to provide an image reading apparatus that does not cause image leading edge blurring during reading.
Of course, when developing the alignment unit, the specifications of the image reading apparatus to be developed in the future are not clear. Therefore, even if a specific unit of an image reading apparatus developed in the future notifies the matching unit of the identification ID, the matching unit may not recognize the identification ID.
In this case, the matching unit requests the specific unit to notify the capture information. As acquisition information, if there is acceleration section distance, deceleration section distance, and constant speed information, an optical motor drive profile can be drawn.

Furthermore, as described with reference to FIG. 4, since the writing to the EEPROM 1004 can be performed from the CPU 1501, even in a future product, the contents of the EEPROM 1004 must be updated. It can respond flexibly.
For example, when a major change occurs in the material constituting the reading unit or the material of the member, the behavior of the tip shake described above and the sound generated when the optical motor is activated (sound pressure and sound quality) may change. An example that can be a solution to these problems is to change the form of the indirectity rise curve.

  In this case, data to be updated is obtained from an external device (not shown), but overwritten in the EEPROM 1004 via the interface circuit 1516, ASIC 1505, CPU 1501, and interface circuits 1005-1 and 1005-2 in FIG. Become. Therefore, although the procedure for overwriting is slightly complicated, the EEPROM 1004 is used as a DIP type IC, and the EEPROM 1004 is mounted on the matching unit 1002 by using a mounting method via an IC socket. The purpose can be easily achieved by exchanging (replacing) the data with those already written.

  According to the image reading apparatus in the present embodiment as described above, the matching unit 1002 in FIG. 1 may be used as it is for each product, and the specific unit 1001 may be newly designed. In addition, the newly designed specific unit 1001 is designed so that the interface with the matching unit 1002 and the interface with the ADF are designed in advance, so that the design philosophy can be easily used and the design period and development period can be shortened. .

Further, in this embodiment, the control device mounted on the matching unit 1002 is an ASIC, but this is not limited to cases where control is easy or there is a cost advantage, and separately from the CPU on the specific unit 1001. A provided CPU may be substituted, or in some cases, a combination of a CPU and a small ASIC may be substituted.
The read data of the document image read by such an image reading apparatus is sent to the image output unit 1P.

  Hereinafter, an outline of the image output unit 1P will be described.

  In FIG. 2, the image output unit 1P is roughly divided into an image forming unit 10 (four stations 10a, 10b, 10c, and 10d are arranged in parallel, and the configuration is the same), a paper feeding unit 20, an intermediate transfer. The unit 30 includes a fixing unit 40 and a control unit 80 (not shown in FIG. 2).

  Further, each unit will be described in detail. The image forming unit 10 is configured as described below. Photosensitive drums 11a, 11b, 11c, and 11d as image carriers are pivotally supported at their centers and are driven to rotate in the direction of the arrow. Opposing to the outer peripheral surfaces of the photosensitive drums 11a to 11d, primary chargers 12a, 12b, 12c, and 12d in the rotation direction, optical exposure units 13a, 13b, 13c, and 13d as exposure units, and folding mirrors 16a and 16b. 16c, 16d, developing devices 14a, 14b, 14c, 14d.

  In the primary chargers 12a to 12d, a uniform charge amount of charge is applied to the surfaces of the photosensitive drums 11a to 11d. Next, by exposing the photosensitive drums 11a to 11d through the folding mirrors 16a to 16d with light beams such as laser beams, which are modulated according to the recording image signal, by the exposure units 13a to 13d, there are electrostatic latent images. Form an image.

  Further, the electrostatic latent images are visualized by developing devices 14a to 14d each containing developer of four colors such as yellow, cyan, magenta, and black (hereinafter referred to as “toner”). The visualized visible image (developed image) is transferred to the image transfer areas Ta, Tb, Tc, and Td of the intermediate transfer belt 31 that is an intermediate transfer member.

  After the photosensitive drums 11a to 11d rotate and pass through the image transfer areas Ta to Td, they are not transferred to the intermediate transfer belt 31 by the cleaning devices 15a, 15b, 15c, and 15d and remain on the photosensitive drums 11a to 11d. The drum surface is scraped off and the drum surface is cleaned. By the process described above, image formation with each toner is sequentially performed.

  The paper feeding unit 20 includes cassettes 21a, 21b, a manual feed tray 27 for storing the transfer material P, pickup rollers 22a, 22b, 26 for feeding the transfer material P one by one in the cassette 21a, 21b or from the manual feed tray 27. Have Further, the transfer material P fed from the pickup rollers 22a, 22b, and 26 is fed to the registration rollers 25a and 25b in accordance with the sheet feed roller pair 23 and the sheet feed guide 24, and the image forming timing of the image forming unit. Registration rollers 25a and 25b for feeding the transfer material P to the secondary transfer region Te.

  The intermediate transfer unit 30 will be described in detail. The intermediate transfer belt 31 is opposed to the secondary transfer region Te across the belt 31 as a winding roller, a driving roller 32 that transmits driving to the intermediate transfer belt 31, a driven roller 33 that follows the rotation of the intermediate transfer belt 31, and the belt 31. The secondary transfer counter roller 34 is wound around. Among these, a primary transfer plane A is formed between the driving roller 32 and the driven roller 33. The driving roller 32 is coated with rubber (urethane or chloroprene) having a thickness of several millimeters on the surface of the metal roller to prevent slippage with the belt 31. The drive roller 32 is rotationally driven in the direction of arrow B by a pulse motor (not shown).

  The primary transfer plane A is opposed to the image forming portions 10 a to 10 d, and the photosensitive drums 11 a to 11 d are opposed to the primary transfer surface A of the intermediate transfer belt 31. Therefore, the primary transfer areas Ta to Td are positioned on the primary transfer surface A. Primary transfer chargers 35 a to 35 d are arranged behind the intermediate transfer belt 31 in the primary transfer regions Ta to Td where the photosensitive drums 11 a to 11 d and the intermediate transfer belt 31 face each other. A secondary transfer roller 36 is disposed to face the secondary transfer counter roller 34, and a secondary transfer region Te is formed by a nip with the intermediate transfer belt 31. The secondary transfer roller 36 is pressed against the intermediate transfer belt 31 with an appropriate pressure. Further, downstream of the secondary transfer region Te on the intermediate transfer belt 31, a cleaning blade 51 for cleaning the image forming surface of the intermediate transfer belt 31 and a waste toner box 52 for storing waste toner are provided. .

  The fixing unit 40 includes a fixing roller 41a having a heat source such as a halogen heater therein, a pressure 41b applied to the roller 41a (the roller 41b may also have a heat source), and a nip of the roller pair 41. And a guide 43 for guiding the transfer material P to the portion. Further, the transfer material P further discharged from the roller pair 41 includes an inner discharge roller 44, an outer discharge roller 45, and the like for guiding the transfer material P to the outside of the apparatus.

FIG. 8 shows a block diagram showing the apparatus configuration.
In FIG. 8, the control unit 100 includes a CPU 101 for controlling the operation of the mechanism in each unit, a driver board 200, and the like. When an image forming operation start signal is issued from the control unit 100, feeding of the transfer material P is started from the paper feeding stage selected according to the selected paper size or the like.

Next, a description will be added in accordance with the operation of the apparatus.
When an image forming operation start signal is issued from the control unit 100, first, the transfer material P is sent out one by one from the cassette 21a by the pickup roller 22a. The transfer material P is guided between the paper feed guides 24 by the paper feed roller pair 23 and conveyed to the registration rollers 25a and 25b. At that time, the registration rollers 25a and 25b are stopped, and the leading edge of the paper hits the nip portion. Thereafter, the registration rollers 25a and 25b start to rotate in accordance with the timing at which the image forming units 10a to 10d (FIG. 2) start image formation. The rotation of the registration rollers 25a and 25b is set so that the transfer material P and the toner image primarily transferred from the image forming unit 10 onto the intermediate transfer belt 31 exactly coincide with each other in the secondary transfer region Te. ing.

  On the other hand, in the image forming unit 10, when an image forming operation start signal is issued from the control unit 100, the image forming unit 10 is formed on the photosensitive drum 11d at the most upstream in the rotation direction B of the intermediate transfer belt 31 by the process described above. The toner image (development image) is primarily transferred to the intermediate transfer belt 31 in the primary transfer region Td by the primary transfer charger 35d to which a high voltage is applied.

  The primarily transferred toner image is conveyed to the next primary transfer region Tc. In this case, image formation is performed by delaying the time during which the toner image is conveyed between the image forming units 10, and the next toner image is transferred onto the previous image by aligning the registration (image position). It will be. The same process is repeated for the primary transfer areas Ta and Tb of the other colors, and the toner images of four colors are primarily transferred onto the intermediate transfer belt 31 after all.

  Thereafter, when the transfer material P enters the secondary transfer region Te and contacts the intermediate transfer belt 31, a high voltage is applied to the secondary transfer roller 36 in accordance with the passing timing of the transfer material P. Then, the four color toner images formed on the intermediate transfer belt 31 by the above-described process are collectively transferred onto the surface of the transfer material P. Thereafter, the transfer material P is accurately guided to the nip portion of the fixing roller pair 41 by the conveyance guide 43. The toner image is fixed on the paper surface by the heat of the fixing roller pair 41 and the pressure of the nip. Thereafter, the transfer material P is conveyed by the inner and outer discharge rollers 44 and 45, and the transfer material P is discharged outside the apparatus.

  In this type of image forming apparatus, mechanical attachment errors between the photosensitive drums 11a to 11d, optical path length errors of the laser beam generated by the exposure units 13a to 13d, optical path changes, warpage due to LED ambient temperature, and the like. In order to correct a registration shift of each color image formed on each of the photosensitive drums 11a to 11d, that is, a color shift (registration shift), on the transfer area A surface, downstream of all the image forming units 10. At a position before the belt 31 is folded back by the driving roller 32, a registration sensor 60 for detecting a registration error is provided.

  FIG. 8 is a block diagram illustrating a unit (board) configuration in which each member of the image forming apparatus 1 is classified according to function and configured as a control unit. In the figure, reference numeral 100 denotes a CPU board, which is a specific unit, and includes a CPU 101, ROM 102, RAM 103, and ASIC 104. Reference numeral 200 denotes a driver board that drives a DC load, a driver 202 that drives the motor M1, a driver board that includes an I / O circuit such as an input circuit of the sensor S2, and a driver circuit. The ASIC 104 and the ASIC 201 of the board are connected by a high-speed serial communication device. Of course, in this embodiment, the high-speed serial communication using the ASIC is used. However, the CPU 101 on the CPU board 100 may directly communicate with the ASIC 201 on the driver board 200.

The relay board (matching unit) 300 will be described with reference to FIG. The relay board 300 is a matching unit having an interface to which a plurality of different units can be connected.
Next, the relay board 300 and the driver unit 500 will be described with reference to FIG. The relay board 300 is an alignment unit having an interface to which a plurality of different driver units can be connected, absorbs the difference between the I / F of each driver unit and the I / F of a specific unit, and has the characteristics of each driver unit. It is a unit for performing fine control according to the requirements. The driver unit 500 is a unit for driving each part classified by function in the image forming apparatus of this embodiment. Here, it is classified into four units, 500_1 is assumed to be a paper feed unit, 500_2 is a paper conveyance unit, 500_3 is a duplex conveyance unit, and 500_4 is a paper discharge unit. Although there are other functional units to be classified in the image forming apparatus, the description is omitted here for the sake of simplicity.

  First, the relay board 300 will be described. Reference numeral 310 denotes an I / F unit (connector) connected to the specific unit 100. The I / F is a serial system and is connected to the CPU 301. The CPU 301 is a so-called 1 chip CPU with a built-in ROM / RAM, and performs command exchange with the specific unit 100, load control corresponding to the command, and the like. The ASIC 304 is connected to the CPU 301 via a CPU bus, and generates an I / F signal with each driver unit. The I / F signals generated here are inputted to and outputted from connectors 311, 312, 313 and 314, respectively. The I / F signal generated here is a signal for driving each load connected to each driver board, and is connected by serial I / O.

  Next, the driver unit 500 will be described with 500_1 as a representative. In FIG. 9, reference numeral 500_1 denotes a driver unit in the paper feeding unit, which is connected to the I / F connector 311 of the relay board 300 via the I / F connector 501. The I / F signal is input to the ASIC 502, and the ASIC 502 is connected to the I / F connectors 500_11 and 500_12. The ASIC 502 has a function of converting the serial signal input from the relay board 300 into parallel, outputting the result to each I / F connector, and converting the input signal in parallel to serial and transmitting it to the relay board 300. . The driver unit 500 has an ID setting device 503 and also has a function of transmitting the set ID to the relay board 300 via the ASIC 502. Here, the ID setting device 503 is assumed to be a 4-bit DIP switch or the like. The I / F connector 501 is common to all four driver units. A common ASIC 502 is also used.

  Next, the signal flow of the driver unit 500_1 will be described. The I / F signal with the relay board 300 is a serial signal as shown in FIG. A signal transmitted from the relay board 300 to the driver unit 500_1 is a 16-bit serial signal, which is Tx. The signal transmitted from the driver unit 500_1 to the relay board 300 is a 20-bit serial signal, and this is Rx. The driver unit 500_1 converts the received Tx signal into a 16-bit parallel signal.

  This is shown in FIG. In the parallel signal obtained by converting the Tx signal, 4 bits of bits 15 to 12 are assigned to the phase signal of the stepping motor 500_13, 4 bits of bits 12 to 8 are assigned to the phase signal of the stepping motor 500_14, and the remaining 8 bits are reserved. On the other hand, as shown in FIG. 11B, the output of the sensor 500_15 is set to bit 15 with the 4 bits of the ID signal as the head, and the remaining 14 bits are reserved, and the parallel-to-serial converted signal is transmitted to the relay board 300 as the Rx signal. . In this way, the I / F of the relay board 300 and the driver unit 500_1 is realized. The driver units 500_2, 500_3, and 500_4 have the same basic concept although there is a difference in the connected load and a difference in ID.

  Next, the operation in which the relay board 300 receives a command from the specific unit and drives the driver unit will be specifically described.

  First, in communication immediately after turning on the power, the ID of the driver unit 500_1 is converted into a serial signal by the ASIC 502 and transmitted to the relay board 300. Thereby, the relay board 300 can detect that the unit connected to the I / F connector 311 is a driver unit of the paper feed unit. If another unit is connected, it can be detected, and correct control can be performed by switching the communication channel inside the ASIC 304. In other words, since all the I / F connectors 311 to 314 are common, any driver unit can be connected. In this way, the ID is recognized and the control of each I / F can be switched accordingly. It has become. Therefore, the driver units 500_1 to 500_4 are configured to operate without any problem regardless of how they are connected.

  Next, the operation will be described by taking as an example a case where a command “perform paper feeding” is received from a specific unit. The CPU 301 on the relay board 300 stores a program for controlling a motor or the like connected to the driver unit 500_1 of the paper feeding unit at an appropriate timing and giving an appropriate drive signal. The signal is serially output from the I / F connector 311 and input to the ASIC 502 via the I / F connector 501 on the driver unit 500_1. This serial signal is converted from serial to parallel by the ASIC 502, and the stepping motor 500_13 or 500_14 is driven via the I / F connectors 500_11 and 500_12. In addition, a detection signal from the sensor 500_15 for detecting the paper feeding operation is input to the ASIC 502 via the I / F connector 500_12. In the ASIC 502, the signal of the sensor 500_15 is converted from parallel to serial, and transferred to the relay board 300 via the I / F connector 501, thereby informing the timing of paper conveyance in the paper feeding operation.

  In this configuration, for example, fine adjustment such as optimization of the driving method when the stepping motor is changed to another motor can be performed only by changing the program of the CPU 301 on the relay board 300, which has an influence on the entire apparatus. Never give. In this embodiment, the motor is a stepping motor. However, even when the motor is changed to a DC motor, it is possible to cope with the problem by simply rewriting the driver unit hardware and the CPU 301 program on the relay board 300. There is no need to change the specific unit. The same applies when the number of sensors is increased due to a change in the configuration of the paper feed unit. Further, even if the number of driver units increases due to the configuration change of the device, it can be dealt with by increasing the I / F on the relay board 300 and changing the program in the CPU 301. Since no change is required for both hardware and software, versatility can be improved.

  Next, referring to FIG. 12, an interface setting device that allows an interface to be arbitrarily set in a matching unit having an interface to which different units can be connected will be described with a connection example between the relay board 300 and the driver unit 500.

  The relay board 300 is a matching unit having an interface to which a plurality of different driver units can be connected. That is, the relay board 300 is a unit that absorbs the difference between the I / F of each driver unit and the I / F of the specific unit and performs fine control according to the characteristics of each driver unit. The driver unit 500 is a unit for driving each part classified by function in the image forming apparatus of the present embodiment. Here, it is classified into four units, 500_1 is assumed to be a paper feed unit, 500_2 is a paper conveyance unit, 500_3 is a duplex conveyance unit, and 500_4 is a paper discharge unit. Although there are other functional units to be classified in the image forming apparatus, the description is omitted here for the sake of simplicity.

First, the relay board 300 will be described.
The relay board 300 is mounted with a CPU 301 and is connected by an I / F unit (connector) connected to the specific unit 100. In this embodiment, the I / F is a serial system. The CPU 301 is a so-called 1 chip CPU with a built-in ROM / RAM, and performs command exchange with the specific unit 100, load control corresponding to the command, and the like. The ASIC 302 is connected to the CPU 301 via a CPU bus, and generates an I / F signal with each driver unit. The I / F signals generated here are input and output to connectors J301, J302, J303, and J304, respectively. The I / F signal generated here is a signal for driving each load connected to each driver board.

Next, the driver unit 500 will be described with 500_1 as a representative. In FIG. 12, reference numeral 500_1 denotes a driver unit in the paper feed unit, which is connected to the I / F connector J301 of the relay board 300 via the I / F connector. This I / F signal is input to the ASIC 302 mounted on the relay board 300. The ASIC 302 includes a parallel / serial conversion block 302-2 that converts a serial signal input from a specific unit (CPU board) into a parallel signal and converts a parallel signal from the driver board 500 into a serial signal. Further, an ID number is input to the parallel / serial conversion block 302-2 from the driver boards 500-1, 2, 3, and 4. This signal is assigned to the first pin of each of the connectors J301, J302, J303, and J304. The CPU 301 determines the I / F of the driver boards 500-1 to 500-4 based on the ID information from the driver board, and performs programmable connection / change of input / output signals in the block 302-1.
Further, when an analog signal is present in the I / F like the driver board 500-4, the block 302-1 for connecting / changing the input / output signal in a programmable manner is configured by using, for example, an analog switch. Even when digital / analog signals are mixed, input / output signals can be connected / changed in a programmable manner.

  Next, in FIG. 8, reference numeral 400 denotes a high voltage control matching (relay board) unit having an interface capable of connecting a plurality of high voltage power supply function units (driver boards) 600 used in the image forming process. These will be described below in more detail with reference to FIGS.

  In FIG. 13, reference numeral 400 denotes a matching unit for high voltage control, and 401 is a communication control block that performs communication with the specific unit 100. Reference numeral 402 denotes a high voltage constituted by a CPU or the like for receiving a command from the specific unit 100 via the communication control block 401 and sequentially controlling the operation of each high voltage power supply functional unit connected to the high voltage control matching unit 400. This is an operation control block. Reference numeral 403 denotes a high voltage stabilization control block for stabilizing and controlling the output signal of each high voltage power supply functional unit in response to a sequential command from the high voltage operation control block 402. 404a, 404b, 404c,... Are connection connectors in which the high voltage power supply functional units are configured in the same form and have the same function or different high voltage power supply function units in a one-to-one relationship. Reference numerals 405 and 406 denote multiplexers for selecting a signal corresponding to a desired connector from analog signals input from the connection connectors. Reference numerals 407 and 408 denote A / D converters for digitally converting the analog signals selected by the multiplexers 405 and 406, respectively.

  Next, the operation of each block in the above configuration will be described. First, the communication control block 401 receives mode information including a color mode, printing magnification, printing paper size, and the like from the specific unit 100 that controls the entire apparatus, and transmits the information to the high-pressure operation control block 402. When the high-voltage operation control block 402 receives the information and receives the print start signal, the high-voltage operation control block 402 causes each high-voltage power supply functional unit to perform mode control including setting values, timings, periods, and the like based on the previously received mode information. Commands are sequentially given to the high-pressure stabilization control block 403. On the other hand, the high voltage stabilization control block 403 switches the selection signals by the multiplexers 405 and 406 in a time division manner, and controls the A / D converters 407 and 408 to obtain the signal level of a desired analog signal. Drive information for output control is sent to the high-voltage power supply functional unit selected by comparing the obtained signal level with the set value based on the mode information. The above-described control of multiplexer switching, signal level acquisition, and drive information transmission is repeated for each of the high-voltage power supply function units 405 and 406 at predetermined intervals. As a result, the high-voltage signal from each high-voltage power supply functional unit is controlled to a predetermined output value. Furthermore, each high-voltage power supply functional unit is controlled by an output operation according to a predetermined image forming process based on the mode information from the specific unit 100 described above, whereby a desired image formation is executed. .

  Next, a configuration example of the high voltage power supply functional unit will be described with reference to FIG. In the figure, reference numeral 600 denotes a high-voltage power supply functional block, and reference numeral 601 denotes a high-voltage driver connector for connection to the high-voltage control matching unit 400. Reference numeral 602 denotes a drive block that performs a switching operation based on drive information sent from the high-voltage control matching unit 400. Reference numeral 603 denotes a transformation block including a transformer that amplifies the drive signal generated by the drive block. A signal smoothing block 604 smoothes the drive signal amplified by the transformer block 603 to a predetermined polarity. Reference numeral 605 denotes a voltage detection block for monitoring the voltage value of the voltage signal converted into a direct current by the signal smoothing block 604. Reference numeral 606 denotes a current detection block for monitoring the current value of the voltage signal. Reference numeral 607 denotes an output terminal from which the DC converted high voltage signal is output, and reference numeral 608 denotes a ground terminal that constitutes a return path for the high voltage signal.

  In the above configuration, the high voltage control matching unit 400 transmits drive information in the form of a PWM signal or the like to the drive block 602 via the high voltage driver connector 601. When the driving block 602 receives the driving information, the driving block 602 generates a driving signal having a desired power in a switching operation based on the driving information. The transformer block 603 receives the drive signal of the desired power and outputs an AC signal obtained by amplifying the drive signal. The smoothing block 604 rectifies the voltage-amplified AC signal to a predetermined polarity and outputs it to the output terminal 607 as a DC signal. The DC signal output to the output terminal 607 is divided by the voltage detection block 605 so that the voltage level can be converted by the A / D conversion block 407 or 408 in the high voltage control matching unit 400, and is connected to the high voltage driver connector. 601 is sent to the matching unit 400 for high pressure control. Further, the load current by the DC signal output to the output terminal 607 flows into the ground terminal 608 through the load, passes through the current detection block 606, and returns to the smoothing block 604 and further to the transformation block 603. At this time, the current detection block 606 processes the load current into a voltage level that can be converted by the A / D conversion block 407 or 408 in the high-voltage control matching unit 400, and the high voltage via the high-voltage driver connector 601. It transmits to the matching unit 400 for control.

  According to the above operation, for example, when each control block in the high voltage control matching unit 400 requires a high voltage DC voltage of a desired constant voltage, each control device in the high voltage control matching unit 400 is A voltage detection signal of a desired high-voltage power supply functional unit is read out using the multiplexer 405 or 406 in a time division manner, and based on this, the driving state of the high-voltage power supply functional unit is switched at predetermined time intervals. By repeatedly executing this control, the output voltage of the selected high-voltage power supply functional unit can be controlled to a desired voltage value.

  Hereinafter, an example in which a plurality of decks are mounted outside the image forming apparatus will be described with reference to FIGS. This is an example in which a deck has a plurality of paper feed units, each of which has a CPU or relay board, and the configuration of the CPU or relay board in the deck can be changed.

  The first configuration is the configuration shown in FIG. One CPU at the entrance of the deck is connected to the LAN configuration on the main configuration communication line that is a communication line with the main configuration, and a CPU that manages each unit is arranged under the umbrella. Thus, since the main body only needs to communicate with the above-mentioned one CPU instead of the plurality of CPUs in the deck, the load on the main body side is most reduced. In addition, this example limits the configuration of a plurality of CPUs in the deck, and does not limit the communication mode between the CPU having a LAN configuration with the main body and each of the CPUs being served thereby.

  The second configuration is the configuration shown in FIG. A CPU / relay board for controlling each unit from the main body is connected to the LAN configuration equally. Therefore, each CPU in the deck can directly communicate with the main body, and high-speed main body communication can be realized.

  The third configuration is the configuration shown in FIG. This is a configuration in which one of the CPU / relay boards that control each unit participates in the LAN configuration and transmits information from the main unit to the CPU / relay board for controlling each unit. As shown, the CPU connected to the LAN does not dominate other CPUs. The communication method between the CPUs is not limited.

  In addition, the configuration from the first configuration to the third configuration can be selectively changed so that the CPU connected to the main body through a LAN or each CPU in the deck responds to an error generated in each terminal unit. Thus, it is also possible to configure so that the three configurations are appropriately selected while determining whether to communicate with the main body or to solve within the deck.

  As described above, according to the present embodiment, the matching unit may be used as it is for each product, and the specific unit may be newly designed. In addition, since the specific unit to be newly designed is designed with a predetermined interface as an interface with the matching unit, the design philosophy can be easily used, and the design period and the development period can be shortened.

1 is a block diagram showing the configuration of a control system in an image reading apparatus used in an “image forming apparatus (copier)” that is Embodiment 1. Sectional drawing of the principal part of Example 1 3 is a diagram illustrating an example of an interface between an ADF and a CPU in the image reading apparatus used in Embodiment 1. FIG. 3 is a diagram illustrating an example of an interface between a specific unit and a matching unit in the image reading apparatus used in Embodiment 1. FIG. Block diagram extracting the configuration related to optical motor drive Timing chart for explaining a motor clock generation procedure in the image reading apparatus used in Embodiment 1 FIG. 5 is a diagram showing an optical motor drive profile of the image reading apparatus used in the first embodiment. 1 is a block diagram illustrating a device configuration of an image forming apparatus that is Embodiment 1. FIG. Relay board block diagram Serial signal timing chart Illustration of driver unit Block diagram showing connection of specific unit, alignment unit, and driver board Block diagram showing the configuration of the alignment unit for high pressure control Block diagram showing the configuration of the high-voltage power supply functional unit Diagram showing an example of connecting multiple decks to the image forming apparatus Diagram showing an example of connecting multiple decks to the image forming apparatus Diagram showing an example of connecting multiple decks to the image forming apparatus The figure explaining operation | movement of an image reading apparatus The figure explaining operation | movement of the image reading apparatus carrying ADF. Block diagram showing the configuration of a control system in a conventional image reading apparatus (low speed reading system) Driving profile of reading unit in conventional image reading device (low speed reading system) The figure explaining the motor drive clock generation procedure of the conventional image reading apparatus Figure of Patent Document 1 Block diagram showing the configuration of a control system in a conventional image reading apparatus (high-speed reading system) Driving profile of a reading unit in a conventional image reading apparatus (high-speed reading system)

Explanation of symbols

1001 Specific unit 1002 Matching unit 1003 ASIC
1004 EEPROM
1005-1 Interface circuit 1005-2 Interface circuit 1006 Oscillation circuit 1007 Optical motor 1501 CPU

Claims (6)

An image reading unit driven by an optical motor and reading a document placed on a document table by a line sensor;
It is composed of at least two substrates of a specific unit and an alignment unit, a first control unit is mounted on the specific unit, a second control unit is mounted on the alignment unit, and a drive table for the optical motor is further provided. Non-volatile storage means that stores data for determination and is writable by the first control means is mounted, and the specific unit and the alignment unit are connected by a predetermined interface that does not depend on the specifications of the image reading apparatus A control unit,
With
The matching unit includes a reference clock generating unit having a variable oscillation frequency, a data reading unit configured to read data read from the storage unit at an arbitrary decimation rate, and a reference clock output from the reference clock generating unit. Motor clock generating means for generating a motor clock for driving the optical motor by a combination of a frequency and a thinning rate set in the data reading means;
An image reading apparatus comprising: The image reading apparatus according to claim 1,
The image reading apparatus according to claim 1, wherein the reference clock generating means sets an output frequency according to an identification ID of the specific unit. The image reading apparatus according to claim 1,
The image reading apparatus, wherein the specific unit includes a driver corresponding to a specification of the optical motor. The image reading apparatus according to any one of claims 1 to 3,
The image reading apparatus according to claim 1, wherein the first control means is a CPU. The image reading apparatus according to any one of claims 1 to 4,
The image reading apparatus according to claim 2, wherein the second control means is a CPU. The image reading apparatus according to any one of claims 1 to 5,
The image reading apparatus, wherein the storage unit is mounted on the alignment unit so as to be replaceable.

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