JP4145002B2 - Motor control method, motor control apparatus, document reading apparatus, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor control method, a motor control device, a document reading device, and an image forming apparatus.
[0002]
[Prior art]
In general, in a document reading device (scanner), a scanning optical system is driven at a constant speed in the sub-scanning direction while irradiating exposure light to a document placed on a contact glass by a light source in the scanning optical system. The reflected light corresponding to the document image is imaged on the photosensitive member or imaged on a photoelectric conversion element such as a CCD.
[0003]
A motor is used as a drive source for reciprocating the scanning optical system in the sub-scanning direction. The rotation speed of the motor is controlled according to the input pulse width, and the rotation angle is controlled according to the number of input pulses. In particular, since the motor cannot be started immediately at a constant speed, which is the target reading speed, when starting up to perform the reading operation, the motor should be started up through an acceleration region by slow-up control from the stopped state toward the target reading speed. I have to. When stopping, conversely, the target reading speed state is stopped from the target reading speed state through the deceleration region by the slow-down control.
[0004]
That is, with respect to motor control, there is a desired speed profile, and control corresponding to that is performed. In such a motor control, a plurality of speed control tables in which control information defining the relationship between the speed data value indicating the rotational speed of the DC motor and the driving time of the DC motor are used in advance are used. This is shown in Japanese Patent Publication No. 7-115521.
[0005]
[Problems to be solved by the invention]
Even in Japanese Patent Publication No. 7-115521 using such a speed control table, the main control is the CPU, and the control includes software. In the case of this publication as well, in general, the motor control in the scanner uses an interrupt in the CPU mounted on the scanner control board, and the motor is controlled in software whenever a speed control interrupt occurs. I have to.
[0006]
According to such software control, in addition to the CPU on the main body side, the CPU dedicated to the scanner side is also used on the scanner control board, even when the scanner alone does not exist like an image forming apparatus such as a copying machine. Becomes essential. In addition, it takes time for interrupt processing, which increases the load on the CPU and also takes time for software development.
[0007]
SUMMARY An advantage of some aspects of the invention is to provide a motor control method, a motor control device, a document reading device, and an image forming apparatus that can perform motor control after initial setting by hardware.
[0008]
It is another object of the present invention to provide a motor control method, a motor control device, a document reading device, and an image forming apparatus that can perform exception processing of a motor accompanying sensor detection or the like by hardware without intervention of software.
[0019]
Claim 1 The described invention is input the rotational speed of the motor Pulsed Control according to the pulse width and input the rotation angle of the motor Pulsed A motor control device for controlling according to the number of pulses, wherein the motor pulse information of the pulse width and the number of pulses is divided into a plurality of blocks according to a change in a target control state, and a plurality of presets in order of control. Control table, Counting the pulses, and outputting a table switching signal when the number of pulses included in the control table is reached, A table selector that selects any one of the control tables, and a pulse generator that generates a motor pulse corresponding to the motor pulse information of the control table selected by the table selector and outputs the motor pulse to the motor side Circuit, Controlling the table selector, the plurality A table management circuit for sequentially updating the selection of the control table, The table management circuit stores a counter for counting the table switching signal, a table number for designating a specific control table, and a register for outputting the table number when a specific signal is input from outside. The first control table is selected by the table selector at the start of operation of the motor by resetting the counter, and the selection of the control table is sequentially updated according to the result of counting the table switching signal. When there is a specific signal input from, the table selector is controlled so that the processing is transferred to the control table designated by the table number regardless of the control order. It is characterized by that.
[0020]
Therefore, the information of the pulse width and the number of pulses, which are control items for motor control, is divided into a plurality of blocks according to the change in the control state, and each table is preset in the control order as the control table. Control management of the control table by the management circuit allows a control signal to be selected according to the control order by inputting a start signal at the start of motor operation, and the motor operation can be performed without software intervention according to the motor pulse information in the control table. It can be performed by hardware.
[0021]
Claim 2 The described invention has, as the control table, a control table for constant angular velocity for rotating the motor at a constant angular velocity, and a control table for acceleration / deceleration for rotating the motor at an angular velocity that is accelerated / decelerated. When accelerating / decelerating the motor, the acceleration / deceleration control table and a memory storing a pulse width specified by pulse width information in the control table are used.
[0022]
Therefore, as a typical example of control, the control in the case of constant speed driving and acceleration / deceleration driving of the motor is appropriately performed by hardware by using the control table for constant angular velocity and the control table for acceleration / deceleration. Yes.
[0023]
Claim 3 The described invention is characterized in that each control table includes a current value for motor control, a rotation direction, or other control items in addition to the motor pulse information.
[0024]
Therefore, each control table includes not only the pulse width and the number of pulses, but also the current value for motor control, the rotation direction, or other control items, so that more appropriate motor control is possible under hardware control. Become.
[0027]
Claim 4 In the invention described in the above, the table management circuit can be used regardless of the control order when a specific signal is input from the outside. Specified in the table number In the control table Processing It is possible to set whether to move or not.
[0028]
Therefore, in realizing the motor control device, flexibility regarding motor control specifications can be increased by making it possible to set whether or not to move the process to a specific control table regardless of the control order.
[0029]
Claim 5 In the described invention, the motor includes a rotation at a constant angular velocity and a rotation at an accelerated / decelerated angular velocity as a target control state, and a scanning optical system for exposing and scanning a document is reciprocated in the sub-scanning direction. It is characterized by being a scanner motor.
[0030]
Therefore, the scanner motor with acceleration / deceleration / constant speed drive can be controlled appropriately by hardware, and even when the scanner does not exist alone and is attached to the printer, a dedicated CPU is required for the scanner control board. The structure which does not become possible.
[0031]
Claim 6 The described invention includes a scanning optical system for exposing and scanning a document, and rotation at a constant angular velocity and rotation at an accelerated / decelerated angular velocity as a target control state, and the scanning optical system is moved in the sub-scanning direction. A reciprocating scanner motor, and driving control of the scanner motor 1 to 4 And a motor control device according to any one of the above.
[0032]
Therefore, the drive control of the scanner motor after the initial setting can be realized by hardware control without software intervention.
[0033]
Claim 7 The described invention is claimed. 6 The document reading device described above is provided, and an image is formed on a sheet based on image data read and image-processed by the document reading device.
[0034]
Therefore, since the scanner motor with acceleration / deceleration / constant speed drive is provided with a document reading apparatus that can be appropriately controlled by hardware, the document reading apparatus does not exist alone but is provided together with the image forming apparatus. Even in this case, a configuration in which a dedicated CPU is not essential for the scanner control board is possible.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. First, a schematic configuration of a full-color digital copying machine 1 as an image forming apparatus to which the exemplary embodiment is applied will be described with reference to FIG. The digital copying machine includes a scanner unit 2 as a document reading device that reads an image from a document, and a printer unit 3 as an image recording device that forms an image on printing paper.
[0036]
In the printer unit 3, a toner cleaner 5, a charging charger 6, a laser scanner 7, four developing devices 8, a transfer belt 9 and the like are arranged around a drum-shaped photoconductor 4 arranged in an upper part inside. The transfer belt 9 and the fixing device 10 are arranged in the paper transport path 11 to form an electrophotographic mechanism 12.
[0037]
A plurality of paper feed cassettes 13 and manual feed trays 14 for supplying recording papers having different sizes and directions are provided at positions where the electrophotographic mechanism 12 communicates with the paper conveyance path 11. A drive control mechanism (not shown) supplies the recording paper set in the difference tray 14 or the paper feed cassette 13 to the electrophotographic mechanism 12. The printer unit 3 according to the present embodiment forms a full-color image on recording paper by the electrophotographic mechanism 12, so that Y, M, C, and Bk color toners ( (Not shown) are housed individually.
[0038]
The scanner unit 2 is provided with a contact glass 16 as a document table on the upper surface of the main body housing 15, and a reading document (not shown) is placed on the upper surface of the contact glass 16. The first scanning unit 17 is movably supported at a position facing the contact glass 16, and the second scanning unit 18 is movably supported at a position facing the first scanning unit 17. ing. Here, the first scanning unit 17 is formed of a halogen lamp 19 and a reflection mirror 20 whose reflection surface is inclined at 45 degrees, and the second scanning unit 18 is inclined at 45 degrees and has an inner angle of 90. It is formed by a pair of reflecting mirrors 21 and 22 that face each other at a degree.
[0039]
A three-line CCD 24 is fixedly arranged via an imaging optical system 23 at a position facing the reflection mirror 22 of the second scanning unit 18, and each of the three-line CCD 24 is composed of a CCD array. B line, G line, and R line (none of which are shown) for reading B light, G light, and R light, respectively, are connected at intervals of several lines.
[0040]
Here, since the scanning speed of the first and second scanning units 17 and 18 constituting the scanning optical system is set to 2: 1, the contact glass 16 passes through the first and second scanning units 17 and 18. Therefore, the optical path length of the imaging optical path communicating with the three-line CCD 24 is constant even when the first and second scanning units 17 and 18 are moved. Then, the three-line CCD 24 photoelectrically converts the reflected light of the read original placed on the contact glass 16 and illuminated by the halogen lamp 19 into image data by such a fixed length imaging optical path. The first and second scanning units 17 and 18 are sub-scanned through a motor pulley 26, a belt 27, a pulley 28, a wire (not shown), etc., with a motor 25 as a driving source as shown in FIG. It is driven back and forth in the direction.
[0041]
Next, an outline of the control system will be described. As shown in FIG. 3, the full-color digital copying machine 1 according to the present embodiment has an image processing unit 31 interposed between a scanner unit 2 and a printer unit 3, and includes these scanner unit 2, printer unit 3 and A system control unit 32 having a microcomputer configuration for controlling the image processing unit 31 is provided. An operation unit 33 is connected to the system control unit 32.
[0042]
Here, a configuration example of a drive control circuit of the motor 25 in the scanner unit 2 is shown in FIG. The motor 25 is basically driven by a motor driver 41, and a control circuit 42 as a characteristic motor control device according to the present embodiment is provided for the motor driver 41. First, the motor 25 of the present embodiment is controlled by the control circuit 42 and the motor driver 41 according to the input pulse width, and the rotation angle is controlled according to the input pulse number. A motor is used. In the control circuit 42, the memory 43 has a No. 1-No. n control tables 44 indicated by n are set. These control tables 44 are connected to a table selector 45 for selecting any one of the control tables 44. A table management circuit 46 for controlling the selection operation is connected to the table selector 45.
[0043]
As shown in FIG. 5, for example, each control table 44 includes a control signal area 47a, a motor pulse width area 47b, and a motor pulse number area 47c. In the control signal area 47a, a table type bit indicating whether the control table functions as a constant speed control table (control table for constant angular velocity) 44a or an acceleration / deceleration table (acceleration / deceleration control table) 44b. 48 is set (in this embodiment, when the table type bit 48 is “0” as shown in FIG. 5A, the constant speed control table 44a and the table type bit 48 are shown in FIG. 5B. As shown, the case of “1” is set to be the acceleration / deceleration control table 44b). In addition, in the control signal area 47a, motor control items such as a value representing a current value to the motor 25 when the table is used and a rotation direction of the motor 25 are set. The motor pulse width area 47b stores a value representing the motor pulse width in the constant speed control table 44a, and a value representing the pulse width used in the control table in the acceleration / deceleration control table 44b. The start address of the memory (described later) is set. A value representing the number of motor pulses is set in the motor pulse number area 47c.
[0044]
The output side of the table selector 45 is divided into three systems, a motor control signal system, a pulse width information system, and a pulse number information system, according to the configuration of the areas 47a, 47b, 47c of the control table 44. A pulse number control circuit 49 is provided in the pulse number information system, counts and manages the number of pulses over time, and manages the table when the number of pulses reaches the number of pulses set in the selected control table 44. A switching signal to the next control table 44 is output to the circuit 46.
[0045]
In the pulse width information system, a memory 50, a pulse width selector 51, and a pulse width control circuit 52 functioning as a pulse generation circuit are sequentially provided. In the memory 50, values representing motor pulse widths used when the acceleration / deceleration control table 44b is selected are continuously stored in the order of addresses. Therefore, the memory address 53 is added to the memory 40. Thereby, at the time of acceleration / deceleration, the pulse width is read in order from the head address set in the area 47 b in the acceleration / deceleration control table 44 b and output to the pulse width control circuit 52 via the pulse width selector 51. The pulse width selector 51 performs a pulse width selection operation in accordance with the pulse width information of the area 47b of the selected control table 44. In the case of the area 47b in the acceleration / deceleration control table 44b, the pulse width selector 51 passes through the memory 50 as described above. The selection operation is performed with. This switching between constant speed / acceleration / deceleration is performed according to the information of the table type bit 48 included in the motor control signal. The pulse width control circuit 52 manages the pulse width according to the reference clock so as to be the pulse width selected by the pulse width selector 51, and outputs the actual motor pulse to the motor driver 41.
[0046]
Next, a configuration example of the table management circuit 46 is shown in FIG. The table management circuit 46 is mainly composed of a counter 54 that counts up a table switching signal output from the pulse number control circuit 49. The table No. corresponding to the count value by the counter 54 is displayed. The control table 44 is output to the table selector 45 and used for the selection operation of the control table 44. The counter 54 is set to an initial value 0 at reset. Further, a jump destination table number register 55 is connected to the data-in terminal of the counter 54. When a specific signal as a table number change signal is inputted from the outside, the control table in the jump destination table number register 55 is stored. It is set to jump to the control table 44 when the number is read. Here, the table number change signal is input to the counter 54 via the AND gate 56 together with the table change permission signal, and can be selected and set so as to be effective only when there is a table change permission signal. Further, the table No. of the final control table 44 is displayed. Is set in the final control table register 57, and the No. of the control table 44 that is sequentially updated is set. Is the table No. of the final control table 44. A comparator 58 is provided for determining whether or not the value has been reached. The output of the comparator 58 is input to the clear terminal of the counter 54 through the OR gate 59 together with the reset signal.
[0047]
In such a configuration, in the present embodiment, the motor pulse information of the pulse width that defines the rotation speed of the motor 25 and the number of pulses that defines the rotation angle thereof is matched with the change in the control state targeted by the motor 25. As shown in FIG. 4 in the memory 43 as a control table 44 divided into a plurality of blocks, the control order No. 1-No. n is set in advance, and after such initial setting, a start signal is input when the actual operation of the motor 25 is started. 1-No. By selecting the control table 44 by the table selector 45 under the control of the table management circuit 46 according to n, and controlling the operation of the motor 25 via the motor driver 41 according to the motor pulse information of the control table 44, the software Control is possible only by hardware without any intervention.
[0048]
This will be described more specifically. First, in response to a motor start signal (start signal), No. The first control table 44 of 0 is selected by the table selector 45, the number of pulses set in the area 47c of the control table 43 is sent to the pulse number control circuit 49, and the pulse width data set in the area 47b is pulsed. The data is taken into the width control circuit 52, and counting of a counter (not shown) in the pulse width control circuit 52 is started by a control reference clock. The count value is compared with the captured pulse width data. When they match, the count value is returned to 0, and the motor pulse output logic is inverted to generate a motor pulse with a predetermined pulse width for the motor driver 41. Is output. The motor pulse output causes the pulse number counter in the pulse number control circuit 49 to count up at the rising edge of the pulse.
[0049]
Here, when the control table 44 currently selected and being processed is the acceleration / deceleration control table 44b, the next pulse width data is read from the memory 50.
[0050]
The pulse number counter in the pulse number control circuit 49 is compared with the pulse number data fetched from the control table 44. When they match, the pulse number counter is returned to 0 and the counter 54 in the table management circuit 46 is counted up. . As a result, the table selector 45 causes the next No. The control table 44 is selected.
[0051]
The control table number No. Is the final control table No. set in the final control table register 57 by the comparator 58. n and the final control table No. When n is reached and the number of tables is more than the final number, the counter 54 is cleared via the OR gate 59 to complete the motor pulse output processing and negate the motor control signal.
[0052]
In this way, the pulse information initially set by the control table 44, the motor control signal, and the control order No. of the control table 44 are set. 0-No. The motor pulse is output to the motor driver 41 by hardware control according to n, and the operation of the motor 25 is controlled.
[0053]
FIG. 7A shows a simple control example for easy understanding. 0, acceleration control table No. 1, control table No. for constant speed 2 shows how the angular velocity of the motor 25 changes (speed profile) when the motor 25 is controlled by hardware.
[0054]
On the other hand, when a specific signal that is a table number change signal is input from the outside under the condition that the table change permission signal is set to be valid, data (control table) that is initialized in advance in the jump destination table number register 55 is input. No.) is loaded into the counter 54, whereby the control table 44 selected by the table selector 45 moves to a new control table regardless of its control order. For this reason, it is possible to control to stop at a specific position as shown in FIG. In FIG. 7B, the control table No. 2 with the input of the table number change signal, a predetermined control table No. An example of flying to 20 is shown. Therefore, if the external table number change signal is a signal based on an error sensor or the like in the scanner unit 2, hardware that uses the control table 44 for exceptional processing such as controlling the motor 25 to stop by the sensor output. Control can be performed without software intervention.
[0055]
Therefore, according to the present embodiment, when the scanner unit 2 does not exist as a single scanner as in the full-color digital copying machine 1, a dedicated CPU for controlling the drive of the motor 25 is required on the scanner control board. In addition, the drive control of the motor 25 can be performed by hardware control in the scanner unit 2.
[0056]
In the present embodiment, an example of application to the full-color digital copying machine 1 has been described as an image forming apparatus. However, the present invention is not limited to a color copying machine or a digital copying machine, but may be applied to a monochrome copying machine or an analog copying machine. Of course, it may be a facsimile or the like. Further, it may be applied to a single scanner.
[0062]
Claim 1 According to the motor control device of the described invention, information on the pulse width and the number of pulses, which are control items for motor control, is divided into a plurality of blocks according to the change in the control state, and is preset in the control order as each control table. After that, according to the control management of the control table by the table management circuit, the control signal is selected according to the control order by inputting the start signal at the start of the motor operation, and according to the motor pulse information of the control table. Since the motor operation is controlled, the motor operation can be controlled by hardware without intervention of software. Claims 1 According to the motor control device of the described invention, when a specific signal is input from the outside, the process is transferred to the specific control table regardless of the control order. Therefore, it is possible to perform exceptional processing based on a specific signal input by hardware without software intervention.
[0063]
Claim 2 According to the described invention, the claims 1 In the described motor control device, as a typical example of control, by using the control table for constant angular velocity and the control table for acceleration / deceleration, the control in the case of constant speed driving and acceleration / deceleration driving of the motor is used. It can be done properly by hardware.
[0064]
Claim 3 According to the described invention, the claims 1 or 2 In the described motor control apparatus, each control table includes, in addition to motor pulse information, a current value for motor control, a rotation direction, or other control items. Control becomes possible.
[0066]
Claim 4 According to the described invention, the claims Any one of 1 to 3 In realizing the motor control apparatus described above, it is possible to freely set whether or not to move the process to a specific control table regardless of the control order, so that flexibility regarding the specifications of the motor control can be increased.
[0067]
Claim 5 According to the described invention, the claims 1 to 4 In the motor control device according to any one of the above, the scanner motor with acceleration / deceleration / constant speed drive can be appropriately controlled by hardware, even when the scanner does not exist alone and is attached to the printer. The scanner control board can be configured not to require a dedicated CPU.
[0068]
Claim 6 According to the document reading apparatus of the described invention, drive control of the scanner motor after the initial setting can be realized by hardware control without software intervention.
[0069]
Claim 7 According to the image forming apparatus of the described invention, since the scanner motor with acceleration / deceleration / constant speed driving is provided with the document reading apparatus that can be appropriately controlled by hardware, the document reading apparatus does not exist alone and image formation is performed. Even in the case where the scanner is integrated with the apparatus, the scanner control board can be configured not to require a dedicated CPU.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a full-color digital copying machine showing an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram showing the scanner unit in an enlarged manner.
FIG. 3 is a block diagram showing an outline of a control system.
FIG. 4 is a block diagram showing a circuit configuration of a motor control device.
FIG. 5 is an explanatory diagram showing a configuration example of the control table.
FIG. 6 is a block diagram illustrating a configuration example of a table management circuit.
FIG. 7 is a velocity diagram showing a control example.
[Explanation of symbols]
1 Image forming device
2 Document reader
17, 18 Scanning optical system
25 Motor, scanner motor
42 Motor controller
44 Control table
44a Control table for constant angular velocity
44b Control table for acceleration / deceleration
45 Table selector
46 Table management circuit
50 memory
52 Pulse generation circuit

Claims (7)

A motor control device for controlling a rotation speed of a motor according to a pulse width of an input pulse and controlling a rotation angle of the motor according to a pulse number of the input pulse ;
A plurality of control tables set in advance in the order of control divided into a plurality of blocks according to the change in the control state of the motor pulse information of the pulse width and the number of pulses,
A table selector that counts the pulses, outputs a table switching signal when the number of pulses included in the control table is reached, and selects any one of the plurality of control tables;
A pulse generation circuit that generates a motor pulse corresponding to the motor pulse information of the control table selected by the table selector and outputs the motor pulse to the motor side;
A table management circuit that controls the table selector and sequentially updates selection of the plurality of control tables,
The table management circuit stores a counter for counting the table switching signal, a table number for designating a specific control table, and a register for outputting the table number when a specific signal is input from outside. The first control table is selected by the table selector at the start of operation of the motor by resetting the counter, and the selection of the control table is sequentially updated according to the result of counting the table switching signal. A motor control device that controls the table selector so as to shift the process to a control table designated by the table number regardless of the control order when a specific signal is input from . As the control table, a control table for constant angular velocity for rotating the motor at a constant angular velocity,
An acceleration / deceleration control table for rotating the motor at an accelerated / decelerated angular velocity,
According to claim 1, characterized in that to use a memory having stored a pulse width specified by the pulse width information in the control table and the control table for the acceleration and deceleration when to acceleration and deceleration of the motor Motor control device.   3. The motor control apparatus according to claim 1, wherein each control table includes a current value for motor control, a rotation direction, or other control items in addition to the motor pulse information. The table management circuit is capable of setting whether or not to move the process to the control table designated by the table number regardless of the control order when a specific signal is input from the outside. Item 4. The motor control device according to any one of Items 1 to 3 . The motor is a scanner motor that includes rotation at a constant angular velocity and rotation at an accelerated / decelerated angular velocity as a target control state, and reciprocally moves a scanning optical system for exposing and scanning a document in the sub-scanning direction. The motor control device according to claim 1 , wherein the motor control device is a motor control device. A scanning optical system for exposing and scanning a document;
The target control state includes rotation at a constant angular velocity and rotation at an angular velocity that is accelerated or decelerated.
A scanner motor for reciprocating the scanning optical system in the sub-scanning direction;
An original reading apparatus comprising: the motor control apparatus according to claim 1 , wherein the motor control apparatus drives and controls the scanner motor. A document reading device according to claim 6 ,
An image forming apparatus that forms an image on a sheet based on image data that has been read and image-processed by the document reading apparatus.

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