JP5987659B2 - Image forming apparatus and image forming apparatus control method - Google Patents

Description

  The present invention relates to an image forming apparatus and a method for controlling the image forming apparatus, and more particularly to resetting a counter for controlling the position of a recording head.

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Such an image processing apparatus is often configured as a multifunction machine that can be used as a printer, a facsimile, a scanner, or a copier by providing an imaging function, an image forming function, a communication function, and the like.

  Among such image processing apparatuses, as an aspect of a printer that is used for outputting digitized information, there is a printer that employs an inkjet method (hereinafter referred to as an inkjet printer). An ink jet printer is equipped with a recording head including nozzles for ejecting ink, and image forming output is executed by ejecting ink from the nozzles while moving the recording head in the main scanning direction.

  An encoder sheet method is used for positioning control when moving the recording head in the main scanning direction. That is, the marks drawn on the sheet at predetermined intervals are read by a sensor according to the movement of the recording head, and the position of the recording head is recognized and controlled based on the detection result.

  In such recording head positioning control, in order to enable highly accurate positioning, it is necessary to perform a homing operation to reset the detection result of the sensor described above after the recording head is positioned at the reference position. As a method of this homing operation, a method has been proposed in which positioning is performed in a state where a carriage on which a recording head is mounted is abutted against a side plate of the apparatus housing (see, for example, Patent Document 1).

  As an aspect of the positioning control using the encoder sheet described above, the encoder sheet itself is drawn with a mark corresponding to 300 LPI (Line Per Inch), and by multiplying the detection result, higher-definition positioning is performed. There is a mode that enables control. For example, in the case of 1200 LPI, it is realized by multiplying the detection result of the 300 LPI encoder sheet by four.

  Specifically, the above-described multiplication format can be configured with two counters, a counter corresponding to 300 LPI and a counter corresponding to multiplication of 300 LPI. In such a case, the counter corresponding to the multiplication may not be reset due to restrictions on the device design. Therefore, depending on the count value of the multiplication counter at the reference position, the error in the count value after the reset as described above may occur. Will occur.

  Such a problem is not limited to the type using an encoder sheet, but can be similarly a problem if it is a positioning control method that controls the position of the carriage by the number of pulses.

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to prevent an error in a count value after resetting a pulse counter at a reference position of a carriage in an image forming apparatus that controls the position of a carriage by the number of pulses. And

  In order to solve the above problems, an aspect of the present invention is an image forming apparatus that performs image formation output while moving an image forming unit relative to an object, and the image forming unit at predetermined intervals. A predetermined interval unit counter that counts signals output according to the movement of the image, and a signal output according to the movement of the image forming unit at intervals equal to the predetermined interval. A division unit loop counter that counts according to a value to be recognized, and the position of the image forming unit is recognized in the equally divided interval units according to the count values of the predetermined interval unit counter and the division unit loop counter, and the image A control unit that performs overall control relating to the formation output operation, and the control unit performs movement control so as to press the image forming unit against one end of a moving range, and the image forming unit A count value in the equally divided interval unit corresponding to the interval from the state pressed against the end portion to the position where it stopped thereafter is acquired as reference position recognition process information, and the acquired reference position recognition process information indicates The count value is converted from the unit of the equally divided interval to the unit of the predetermined interval, the converted count value is set in the predetermined interval unit counter, and the image forming unit is pressed against the end portion. After the count value of the division unit loop counter in the obtained state is subtracted from the value indicating the position of the image forming unit recognized by the equally divided interval unit, the image forming unit is pressed against the end The count value of the division unit loop counter at the stopped position is equal to the division unit loop counter in a state where the image forming unit is pressed against the end. When the count value is converted from the unit of the equally divided interval to the unit of the predetermined interval, the converted count value is counted as an extra one count The count value indicated by the reference position recognition processing information corrected so as to become is converted into a unit for each predetermined interval.

  According to another aspect of the present invention, there is provided a control method for an image forming apparatus that performs image forming output while moving an image forming unit relative to an object. A predetermined interval unit counter for counting a signal output in accordance with the movement of the image forming unit; and a signal output in accordance with the movement of the image forming unit for each interval at which the predetermined interval is equally divided. A division unit loop counter that counts at a value that loops at each interval, and the position of the image forming unit in the equally divided intervals according to the count values of the predetermined interval unit counter and the division unit loop counter And controlling the image forming unit so that the image forming unit is pressed against one end of the moving range, and the image forming unit is pressed against the end. The count value in the equally divided interval unit according to the interval from the attached state to the position where it was stopped thereafter is acquired as reference position recognition processing information, and the count value indicated by the reference position recognition processing information is The unit for each divided interval is converted to the unit for the predetermined interval, the converted count value is set in the first predetermined interval unit counter, and the image forming unit is pressed against the end portion The count value of the division unit loop counter in the state is subtracted from the value indicating the position of the image forming unit recognized by the equally divided interval unit, and stopped after the image forming unit is pressed against the end portion The count value of the division unit loop counter at the position is the count value of the division unit loop counter in a state where the image forming unit is pressed against the end. When the count value is smaller than the value, when the count value is converted from the unit of the equally divided interval to the unit of the predetermined interval, the converted count value is a value counted by one extra count. The count value indicated by the reference position recognition processing information corrected in step 1 is converted into a unit for each predetermined interval.

  According to the present invention, it is possible to enable image formation output according to the engine characteristics of image formation output without degrading the image quality.

1 is a diagram illustrating a hardware configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows the function structure of the engine which concerns on embodiment of this invention. It is a figure which shows the movement aspect of the carriage which concerns on embodiment of this invention. It is a figure which shows the aspect of the encoder sheet which concerns on embodiment of this invention. It is a figure which shows arrangement | positioning of the sensor element of the main scanning encoder sensor which concerns on embodiment of this invention. It is a figure which shows the aspect of the detection signal of the main scanning encoder sensor which concerns on embodiment of this invention. It is a sequence diagram which shows the whole process of the homing operation | movement which concerns on embodiment of this invention. It is a figure which shows the movement aspect of the carriage which concerns on embodiment of this invention. It is a figure which shows the example of the value of each counter in the homing operation | movement which concerns on a prior art. It is a figure which shows the example of the value of each counter in the homing operation | movement which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of engine CPU which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an image forming apparatus that employs an ink jet method will be described with a carriage positioning control for moving in the main scanning direction a recording head on which nozzles for ejecting ink are mounted.

  FIG. 1 is a block diagram showing a hardware configuration of the entire image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment includes the same configuration as that of a general server or PC. That is, the image forming apparatus 1 according to the present embodiment includes a CPU (Central Processing Unit) 11, a RAM (Random Access Memory) 12, a ROM (Read Only Memory) 13, a HDD (Hard Disk Drive) 14, and an I / F 15. 18 is connected. Further, the engine 100 and the operation unit 17 are connected to the I / F 15.

  The CPU 11 is a calculation unit and controls the operation of the entire image forming apparatus 1. The RAM 12 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 11 processes information. The ROM 13 is a read-only nonvolatile storage medium, and stores programs such as firmware. The HDD 14 is a non-volatile storage medium capable of reading and writing information, and stores an OS (Operating System), various control programs, application programs, and the like. A software program for configuring the printer driver described above is also stored in the HDD 14.

  The I / F 15 connects and controls the bus 18 and various hardware and networks. The engine 100 is an image forming unit that actually executes image forming output in the image forming apparatus 1. The operation unit 17 is a user interface such as a touch panel and a hard switch for the user to input information to the image forming apparatus 1.

  In such a hardware configuration, a program stored in a storage medium such as the ROM 13, the HDD 14, or an optical disk (not shown) is read to the RAM 12, and the CPU 11 performs calculations according to those programs, thereby configuring a software control unit. The The function of the image forming apparatus 1 according to the present embodiment is realized by a combination of the software control unit configured as described above and hardware.

  Next, the configuration of the engine 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram showing a carriage control configuration in the engine 100 according to the present embodiment. As shown in FIG. 2, the engine 100 according to the present embodiment includes an engine CPU 101, a carriage 102, a main scanning motor driver 103, and an FPGA (Field-Programmable Gate Array) 200. In FIG. 2, only the control configuration related to the carriage 102 is illustrated, but the control configuration of the engine 100 includes a configuration for controlling the conveyance of a sheet that is a target of image formation output.

  The engine CPU 101 is an arithmetic device that controls the entire engine 100. The engine CPU 101 controls each unit included in the engine 100 according to a program stored in a storage medium such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) (not shown).

  As shown in FIG. 2, the carriage 102 includes a main scanning encoder sensor 104, a head driver 105, and a recording head 106, and moves relative to a sheet that is an image recording medium in the image forming apparatus 1, thereby It is possible to form an image on the whole. The direction in which the carriage 102 moves is the main scanning direction, and the direction in which the paper is conveyed is the sub-scanning direction.

  The main scanning encoder sensor 104 is a sensor that detects a reading result of an encoder sheet installed so that a predetermined mark is detected in accordance with the movement of the carriage 102. The configurations of the main scanning encoder sensor 104 and the encoder sheet will be described in detail later.

  The head driver 105 applies a drive signal constituting a drive waveform supplied from the FPGA 200 to a drive element that generates energy for causing droplets to be ejected from the recording head 106, based on drawing data for one line serially input. The recording head 106 is driven by selectively applying to the recording head 106. The recording head 106 is an image forming output unit having nozzles for ejecting inks of CMYK (Cyan, Magenta, Yellow, blackK) colors.

  The main scanning motor driver 103 drives a motor provided to move the carriage 102 in the main scanning direction based on the pulse signal input from the FPGA 200. The FPGA 200 includes 300 LPI counters 201 and 202, a status counter 203, a 1200 LPI counter value storage units 204 and 205, a motor communication buffer 206, a motor control CPU 207, a PWM (Pulse Width Modulation) module 208, and a head drive circuit 209. The engine CPU 101 The carriage 102 and the main scanning motor driver 103 are operated according to the control. A 300 LPI counter 201, a 300 LPI counter 202, and a status counter 203 are counters that count detection signals on the encoder sheet surface from the main scanning encoder sensor 104.

  The 1200 LPI counter value storage unit 204 is a storage medium that stores a count value multiplied from 300 LPI to 1200 LPI based on the count values of the 300 LPI counter 201 and the status counter 203. The 1200 LPI counter value storage unit 205 is a storage medium that stores a count value multiplied from 300 LPI to 1200 LPI based on the count values of the 300 LPI counter 202 and the status counter 203.

  The control related to resetting the count values of these counters is the gist of the present embodiment. Details of the count values of these counters will be described later together with the configurations of the main scanning encoder sensor 104 and the encoder sheet.

  The motor communication buffer 206 is a buffer for transmitting the movement control of the carriage 102 by the engine CPU 101 to the motor control CPU 207. The motor control CPU 207 outputs a drive signal for driving the main scanning motor driver 103 to move the carriage 102 in accordance with the movement control of the carriage 102 notified from the engine CPU 101 via the motor communication buffer 206. . The PWM module 208 outputs a drive signal for driving the main scanning motor via the main scanning motor driver 103 in accordance with the control by the motor control CPU 207.

  Next, how the carriage 102 moves in the image forming apparatus 1 will be described with reference to FIG. FIG. 3 is a diagram illustrating a mechanical configuration of the moving range of the carriage 102 in the image forming apparatus 1 according to the present embodiment. As shown in FIG. 3, the carriage 102 is equipped with recording heads 106Y, 106M, 106C, and 106K that are recording heads corresponding to CMYK colors, and the recording heads 106 of each color are filled with ink of corresponding colors. The cartridge is connected with a pipe.

  Thereby, the recording head 106 of each color discharges the ink supplied from the cartridge onto the paper P that is a recording medium. Each color recording head 106 is mounted on the carriage 102 with its ejection surface, that is, the nozzle surface facing vertically downward, and the paper P is conveyed vertically below the recording head 106. The paper P is conveyed in a state of being supported by the platen 113 from the side opposite to the side where the recording head 106 is disposed. By ejecting ink from the recording head 116 in the range supported by the platen 113, an accurate image is formed in a state where there is no waving or bending of the paper.

  The carriage 102 is connected to a timing belt 107 that runs along the moving direction of the carriage 102, that is, the main scanning direction. The timing belt 107 is main-scanned by a driving pulley 108 that is rotationally driven by a main-scanning motor 109. By being rotated in the direction, it reciprocates in the main scanning direction along a guide rod (not shown).

  The encoder sheet 110 is disposed along at least the moving range of the carriage 102 along the direction in which the timing belt 107 is stretched. When the surface of the encoder sheet 110 is read by the main scanning encoder sensor 104 mounted on the carriage 102, the position of the carriage 102 in the main scanning direction is recognized by the control unit of the engine 100.

  A maintenance mechanism 111 is disposed at one end of the movement range of the carriage 102. The maintenance mechanism 111 provides a function for maintaining the state of the recording head 106 by cleaning the discharge surface of the recording head 106, capping, discharging unnecessary ink, and the like. At that time, the carriage 102 is moved immediately above the maintenance mechanism 111 by the rotation of the timing belt 107.

  At this time, if the accuracy of the carriage positioning control by the encoder sheet 110 and the main scanning encoder sensor 104 is low, the nozzles of the recording heads 106 of the respective colors mounted on the carriage 102 are not properly capped by the maintenance mechanism 111 and are shifted. It becomes a state. In order to avoid such a state, the positioning control of the carriage by the encoder sheet 110 and the main scanning encoder sensor 104 needs to be performed with high accuracy, which is one of the gist of the present case.

  The carriage 102 is configured to abut against the side wall 112 at the other end of the movement range of the carriage 102. In the image forming apparatus 1 according to the present embodiment, the count value of the 300 LPI counter 201 and the like described above is reset after the carriage 102 is abutted against the side wall 112. As a result, the position of the carriage 102 is accurately recognized every time the image forming apparatus 1 is powered on. Such an operation is called a homing operation. Note that such a homing operation is not limited to each time the power is turned on to the above-described apparatus, and may be performed more frequently in order to maintain the positional accuracy of the carriage 102.

  Next, positioning control of the carriage 102 using the encoder sheet 110, the main scanning encoder sensor 104, and a counter group such as the 300 LPI counter 201 according to the present embodiment will be described.

  FIG. 4 is a diagram schematically illustrating the surface of the encoder sheet 110 according to the present embodiment. As shown in FIG. 4, the encoder sheet 110 according to the present embodiment is a sheet on which black lines are drawn at intervals corresponding to 300 LPI. Since the width of the black line and the width of the blank portion are the same, the encoder sheet 110 according to the present embodiment is in a state where the black line and the white line are drawn alternately at an interval of substantially 600 LPI.

  FIG. 5 is a diagram showing the arrangement relationship of the sensor elements on the detection surface of the main scanning encoder sensor 104 according to the present embodiment. As shown in FIG. 5, two sensor elements 104a and 104b are mounted on the main scanning encoder sensor 104 according to this embodiment. The two sensor elements 104a and 104b are arranged with a gap g as shown in FIG. 5 in the direction in which the black lines and white lines described in FIG. 4 are alternately drawn. Therefore, the timing of the detection signal on the surface of the encoder sheet 110 by the sensor element 104a and the sensor element 104b is detected at an interval corresponding to the gap g shown in FIG.

  FIG. 6 is a diagram illustrating timings of detection signals on the surface of the encoder sheet 110 by the sensor elements 104a and 104b, and count-up timings of the 300 LPI counters 201 and 202 and the status counter 203, respectively. In FIG. 6, the detection signal by the sensor element 104a is an encoder pulse A phase, and the detection signal by the sensor element 104b is an encoder pulse B phase.

As shown in the timing t ₁ in FIG. 6, when the sensor 104 element a carriage 102 is contained in the main scanning encoder sensor 104 while moving in one direction in the main scanning direction is in a state to read the black line, the signal of A phase rises . The A-phase signal is input to the 300 LPI counters 201 and 202, and the 300 LPI counters 201 and 202 thereby count the numerical values.

The main scanning encoder sensor 104 outputs a status pulse in response to the rising edge of the A phase signal. This status pulse is input to the status counter 203. Thereby, the status counter 203 counts a numerical value. Here, as shown with the "st0" in FIG. 6, illustrating a case where the status counter 203 by counting at the timing t ₁ becomes "0" as an example. Whether the counter is counted up or counted down is determined according to the rotation direction of the main scanning motor 109.

Furthermore the carriage 102 is moved, the sensor 104 element b is in a state to read the black line, as shown in the timing t ₂ in FIG. 6, the signal of B phase rises. At the rising timing of the B phase, the main scanning encoder sensor 104 outputs a status pulse. As a result, similarly to the above, the status counter 203 counts the numerical value, and the count value becomes “1”.

Furthermore the carriage 102 is moved, the sensor element 104a is in a state that does not read the black line, as shown in a timing t ₃ of Figure 6, the signal of the A phase falls. At the fall timing of the A phase, the main scanning encoder sensor 104 outputs a status pulse. As a result, similarly to the above, the status counter 203 counts the numerical value, and the count value becomes “2”.

Furthermore the carriage 102 is moved, the sensor element 104b is in a state that does not read the black line, as shown in a timing t ₄ of Figure 6, the signal of the B phase falls. At the fall timing of the B phase, the main scanning encoder sensor 104 outputs a status pulse. As a result, similarly to the above, the status counter 203 counts the numerical value, and the count becomes “3”.

Furthermore the carriage 102 is moved, the sensor element 104a is in a state in which re-reads the black line, as shown in the timing t ₅ in FIG. 6, the signal of A phase rises. As a result, the 300 LPI counters 201 and 202 again count the numerical values. The main scanning encoder sensor 104 outputs a status pulse when the A phase signal rises. As a result, the status counter 203 counts numerical values as described above. Status counter 203 of the present embodiment is a 2-bit counter, the count value at the timing t ₅ is returned to "0". That is, the count value of the status counter 203 loops every 300 LPI. Migration, the same processing as the timing t ₂ later is repeated.

  As described above, in the positioning control of the carriage 102 according to the present embodiment, the 300 LPI counters 201 and 202 count the numerical value according to the reading result of the 300 LPI encoder sheet, and the status counter according to the quadruple status pulse. 203 counts numerical values from “0” to “3”.

  The 1200 LPI counter 204 stores a count value at 1200 LPI based on the count values of the 300 LPI counter 201 and the status counter 203, and the 1200 LPI counter 205 stores 1200 LPI based on the count values of the 300 LPI counter 202 and the status counter 203. Holds the count value at. Specifically, the 1200 LPI counters 204 and 205 hold the count value at 1200 LPI by adding the count value of the status counter 203 to a value four times the count value of the 300 LPI counters 201 and 202, respectively.

  In such a configuration, the gist of the present embodiment relates to the accuracy of the counter value after reset in the counter reset in the homing operation. As an explanation of the gist according to the present embodiment, a homing operation in the image forming apparatus 1 will be described first. FIG. 7 is a sequence diagram showing operations of the engine CPU 101 and the motor control CPU 207 in the homing operation of the present embodiment.

  As shown in FIG. 7, first, the engine CPU 101 transmits a command for starting control of the homing operation to the motor control CPU 207 via the motor communication buffer 206 (S701). Upon receiving the command from the engine CPU 101, the motor control CPU 207 controls the PWM module 208 to move the carriage 102 so as to abut against the side wall 112 as shown in FIG. 8A (S702).

  The motor control CPU 207 continues the control in S702 until it is detected that the carriage 102 has contacted the side wall 112. It can be determined from the counter value in the 1200 LPI counter value storage unit 205 that the carriage 102 has come into contact with the side wall 112. That is, it can be determined that the carriage 102 is in contact with the side wall 112 when the counter value has not changed for a predetermined period or longer.

  As a result of the carriage 102 coming into contact with the side wall 112 and the motor control CPU 207 stopping the driving of the main scanning motor driver 103, the carriage 102 may rebound as shown in FIG. Therefore, the motor control CPU 207 waits until it stops at the position where the carriage 102 has bounced back (S703). The standby time in S703 is, for example, 1 second.

  The motor control CPU 207 can refer to the value in the 1200 LPI counter value storage unit 205 after starting the movement of the carriage in S702 and then stopping the movement of the carriage and waiting until the carriage stops in S703. Then, the motor control CPU 207 obtains the extreme value of the counter value in the meantime, that is, the count value of the 1200 LPI counter value storage unit 205 in the state where the carriage 102 is closest to the side wall 112 and is in standby in S703. The count value of the 1200 LPI counter value storage unit 205, that is, the current location is acquired (S704).

  In the image forming apparatus 1 according to the present embodiment, by setting the encoder value at 1200 LPI in a state in which the carriage 102 is closest to and in contact with the side wall 112 as “0” in software, that is, in recognition by the engine CPU 101, Perform homing operation. Therefore, the motor control CPU 207 notifies the engine CPU 101 of the difference between the extreme value acquired in S704 and the current value, that is, the encoder value at 1200 LPI corresponding to the amount of movement of the carriage 102 from the side wall 112, as the reset value. The engine CPU 101 is reset (S705).

  The engine CPU 101 that has received the reset value from the motor control CPU 207 resets the 300 LPI counter 201 based on the received reset value and performs software reset for correcting the value in the 1200 LPI counter value storage unit 204 (S706). With such an operation, the homing operation according to the present embodiment is completed.

  Here, in the FPGA 200 according to the present embodiment, the 300LPI counter 202 and the 1200LPI counter value storage unit 205, which are counters corresponding to the motor control CPU 207, are set to predetermined numerical values without resetting each time the power is turned on. It is controlled in the range. Therefore, the status counter 203 used to determine the count value of the 1200 LPI counter value storage unit 205 together with the 300 LPI counter 202 is not reset.

  On the other hand, the engine CPU 101 needs to check the accuracy of positioning control of the carriage 102 every time the power is turned on, so the 300 LPI counter 201 is reset in the homing operation. However, since the count value of the 1200 LPI counter value storage unit 204 is determined by the 300 LPI counter that is reset and the status counter 203 that is not reset, an error occurs according to the count value of the status counter 203.

  Here, an error in the count value of the 1200 LPI counter value storage unit 204 before and after the reset will be described with reference to FIG. FIG. 9 is a table showing values before and after resetting when the carriage 102 is in contact with the side wall 112, that is, when the count value of the status counter 203 at the above-described extreme value is “3”. For example, when there is no rebound from the side wall 112, that is, when the above-described reset value is “0”, the value of “0” in 1200 LPI is “0” even if converted to 300 LPI. The CPU 101 resets the 300 LPI counter 201 with “0”.

  In this case, since the value of the status counter 203 is “3”, the value indicated by the 1200 LPI counter value storage unit 204 is “3”, and the difference from “0” that is the encoder value to be actually recognized is “3”. It becomes. As a result, the software reset value to be set by the engine CPU 101 is “−3”.

  On the other hand, when the bounce amount from the side wall 112 is “3” as the count value at 1200 LPI, that is, when the reset value is “3”, the value “3” at 1200 LPI is converted to 300 LPI. Is also “0”, the engine CPU 101 resets the 300 LPI counter 201 to “0”.

  In this case, since the value of the status counter 203 is “2” as a result of counting according to the amount of rebound “3”, the value indicated by the 1200 LPI counter value storage unit 204 is “2”. The difference from “3” which is the encoder value to be recognized is “−1”. As a result, the software reset value to be set by the engine CPU 101 is “+1”, which is different from the case described above.

  Further, when the amount of rebound from the side wall 112 is “5” as a count value at 1200 LPI, that is, when the above-described reset value is “5”, the value of “5” at 1200 LPI is converted to 300 LPI. According to the calculation result of 5/4 = 1 remainder 1, it becomes “1”, and the engine CPU 101 resets the 300 LPI counter 201 to “1”.

  In this case, since the value of the status counter 203 is “0” as a result of being counted according to the amount of rebound “3”, the value indicated by the 1200 LPI counter value storage unit 204 is “4”. The difference from “5” which is the encoder value to be recognized is “−1”. As a result, the software reset value to be set by the engine CPU 101 is “+1”, which is also different from the case of “−3” described above.

  Such an erroneous result is that when the 1200 LPI reset value is converted to 300 LPI and set in the 300 LPI counter 201, the count value of the status counter 203 is not reset before and after the reset, This is because a mismatch occurs with the counter 201.

  Such a problem occurs because the count value of the status counter 203 cannot be reset when the 300 LPI counter 201 is reset. In this embodiment, the engine CPU 101 and the motor control CPU 207 share the status counter 203, and the motor control CPU 207 uses the counter within a predetermined value range without resetting. The count value of the status counter 203 cannot be reset. However, the present invention is not limited to this, and there are various factors such as restrictions on the device design that cannot reset the count value of the status counter 203.

  In the present embodiment, the status counter 203 is shared by the engine control CPU 101 and the motor control CPU 207. However, there may be a mode in which a status counter is prepared for each of the engine control CPU 101 and the motor control CPU 207. Even in such a case, it is still difficult to reset the count value of the status counter 203 due to the above-mentioned factors in designing the apparatus, and the same problem as described above occurs.

  In this embodiment, the motor control CPU 207 controls the main scanning motor driver 103 via the PWM module 208, but a configuration in which the engine control CPU 101 performs similar control is also possible. That is, in this embodiment, the engine control CPU 101 and the motor control CPU 207 function as a control unit that controls the entire engine in conjunction with each other. However, the engine control CPU 101 functions as a single control unit that controls the entire engine. It is also possible to function.

  In this case, the 300 LPI counter 202 and the 1200 LPI counter value storage unit 205 are not necessary. However, since the above-described problem is caused by resetting the 300 LPI counter 201, the engine control CPU 101 performs main scanning motor driver via the PWM module 208. Even when controlling 103, a similar problem may occur.

  In order to cope with such a harmful effect, the engine CPU 101 according to the present embodiment responds to the extreme value described above, that is, the value of the status counter 203 in a state where the carriage 102 is in contact with the side wall 112 and the position of the carriage 102 after the bounce. Depending on the difference from the value of the status counter 203, the reset processing of the 300 LPI counter 201 is changed. This is one of the gist according to the present embodiment.

  Hereinafter, the reset process by the engine CPU 101 according to the present embodiment will be described with reference to the flowcharts of FIGS. 10 and 11 corresponding to FIG. 9. FIG. 10 is a table showing each value before and after the reset when the count value of the status counter 203 at the extreme value is “3” as in FIG. 9. When there is no rebound from the side wall 112, that is, when the above-described reset value is “0”, the processing is the same as in FIG. 9, and the software reset value is “−3”.

  On the other hand, for example, when the amount of rebound from the side wall 112 is “3” as the count value at 1200 LPI, that is, when the reset value is “3”, the count value of the status counter 203 is “ 2 ”. That is, the count value of the status counter 203 returns to “0” once until the carriage 102 bounces off the side wall 112 and stops at the current position, and at the same time, the 300 LPI counter is incremented by one.

  However, as described with reference to FIG. 9, even if the reset value “3” at 1200 LPI is divided by 4 and converted to 300 LPI, 3/4 = 0 becomes “0” when the remainder is 3, and the 300 LPI counter 201 is reset. Since “0” is set as the subsequent value, the count value “0” of the 300 LPI counter 201 and the count value “2” of the status counter 203 become irrelevant illegal values.

  For this reason, the engine CPU 101 according to the present embodiment acquires a reset value as shown in FIG. 11 (S1101), and counts the status counter 203 when converting the reset value to 300 LPI to reset the 300 LPI counter. When the value is smaller than the count value of the status counter 203 at the extreme value described above, that is, the count value of the status counter 203 when the carriage 102 is in contact with the side wall 112 (S1102 / YES), that is, the carriage 102 is on the side wall. When the 300LPI counter 201 is counted at least plus 1 because it bounced from the time, when the reset value is converted to 300LPI, the value after 300LPI conversion is forcibly incremented by 1, so that the number of multiplications depends on the multiplication number. Reset value Plus to be corrected in the capital value (S1103).

  In other words, the determination in S1102 is generated based on the count value of the 300 LPI counter 201 and the count value of the status counter 203 because the remainder is discarded as described above by converting from 1200 LPI units to 300 LPI units. This is a determination to detect a state in which the count value of the 1200 LPI counter value storage unit 204 is decreased by one count of the 300 LPI counter.

  Actually, in the case shown in FIG. 10, when the encoder value after bounce is “4”, “5”, “6”, the status value once returned to “0” by the movement after bounce, and 300 LPI The counter is counted once. However, since the status value at the wall is “3”, the reset values are “1”, “2”, and “3”, respectively, and simply converted to 300 LPI will be “0”. Correcting such a state is the gist of the present embodiment.

  The multiplication number according to the present embodiment is “4”. Therefore, in order to force the 300 LPI value to be incremented by 1 when the 1200 LPI value is converted to 300 LPI, the value “3” or “4” may be added to the reset value. In the example of FIG. 10, the value “4” is added to the reset value. As a result, the corrected reset value is “7”.

  The engine CPU 101 converts the corrected value “7” from 1200 LPI to 300 LPI (S1104). In this case, since 7/4 = 1 is 3, and the converted value is “1”, the engine CPU 101 sets a value of “1” in the 300 LPI counter 201 (S1105). Then, the value of the 1200 LPI counter value storage unit 204 is “6”, which is the sum of the count value “1” of the 300 LPI counter 201 and the count value “2” of the status counter 203.

  As a result, the difference from “3”, which is the encoder value to be actually recognized, is “3”, as in the case of the reset value “0”, and the reset value required on the software is “−3”. Become. This value is the count value of the status counter 203 when the carriage 102 is in contact with the side wall 112, and is a value that must be subtracted to set the 1200 LPI counter value storage unit 204 to “0” in that state. .

  Therefore, after setting the value of the 300 LPI counter 201 in this manner, the engine CPU 101 stores the value of the status counter 203 in the above-mentioned polar region as a software reset value that is subtracted on the software from the value of the 1200 LPI counter value storage unit 204. This completes the reset process in the homing operation (S1106).

  As described above, in the image forming apparatus 1 according to the present embodiment, when the status counter 203 is shared by the engine CPU 101 and the motor control CPU 207, the status counter at the home position where the carriage 102 contacts the side wall 112. If the count value of 203 is larger than the count value of the status counter 203 at the position after the carriage 102 has bounced off the side wall 112, and it is found that the value of the 300PLPI counter 201 has been counted up by the bounce, the motor control When the reset value notified from the CPU 207 is converted into 300 LPI, a correction value for forcibly adding the converted value plus one is added to the reset value.

  As a result, even in a low-cost FPGA 200 sharing the status counter 203, inconsistency between the count value of the status counter 203 and the count value of the 300 LPI counter 201 before and after the reset is eliminated, and accurate positioning control of the carriage 102 is performed. Is possible.

  In the above embodiment, the case where the 1200 LPI counter value storage unit 204 for the engine CPU 101 and the 1200 LPI counter value storage unit 205 for the motor control CPU 207 are provided is described as an example. In addition, 1200 LPI encoder value recognition processing based on the count values of the 300 LPI counters 201 and 202 and the count value of the status counter 203 is performed by software processing by the engine CPU 101 and the motor control CPU 207, respectively, and the 1200 LPI counter value is stored. The unit 204 can be omitted.

  In the above embodiment, the engine CPU 101 sets a value corresponding to the count value of the status counter 203 (“3” in the above embodiment), which is an encoder value when the carriage 102 is in contact with the side wall 112, as a software reset. The case where the value is subtracted has been described as an example. In addition, the value stored in the 1200 LPI counter value storage unit 204 may be subtracted by the processing of the engine CPU 101 by register setting for the 1200 LPI counter value storage unit 204.

1 Image forming apparatus 11 CPU
12 RAM
13 ROM
14 HDD
15 I / F
17 Operation unit 18 Bus 100 Engine 101 Engine CPU
102 Carriage 103 Main scanning motor driver 104, 104a, 104b Main scanning encoder sensor 105 Head driver 106, 106Y, 106M, 106C, 106K Recording head 200 FPGA
201, 202 300 LPI counter 203 Status counter 204, 205 1200 LPI counter value storage unit 206 Motor communication buffer 207 Motor control CPU
208 PWM module 209 head drive circuit

JP 2010-215399 A JP 2008-126453 A

Claims (9)

An image forming apparatus that outputs an image while moving an image forming unit relative to an object,
A predetermined interval unit counter that counts signals output in response to movement of the image forming unit at predetermined intervals;
A division unit loop counter that counts a signal that is output in accordance with movement of the image forming unit at intervals of which the predetermined interval is equally divided by a value that loops at the predetermined interval;
A control unit for recognizing the position of the image forming unit in units of the equally divided intervals according to the count values of the predetermined interval unit counter and the division unit loop counter, and for performing overall control relating to the image forming output operation Including
The controller is
The movement is controlled so as to press the image forming unit against one end of the moving range, and the image forming unit is divided equally according to the interval from the state where the image forming unit is pressed to the end to the position where the image forming unit stops thereafter Get the count value in intervals as reference position recognition processing information,
Converting the count value indicated by the acquired reference position recognition processing information from the unit of the equally divided interval to the unit of the predetermined interval, and setting the converted count value in the predetermined interval unit counter, The count value of the division unit loop counter in a state where the image forming unit is pressed against the end is subtracted from the value indicating the position of the image forming unit recognized by the equally divided interval unit,
If the count value of the division unit loop counter has returned to the initial value at least once during the period from when the image forming unit is pressed against the end portion to when it stops, the count value is divided into equal parts. The count value indicated by the reference position recognition processing information corrected so that the converted count value becomes a value counted by one extra when converting from the unit for each interval to the unit for the predetermined interval Is converted into a unit for each predetermined interval. A movement control predetermined interval unit counter that counts a signal output in accordance with movement of the image forming unit at predetermined intervals for movement control of the image forming unit;
The control unit recognizes the position of the image forming unit and moves the image forming unit in the equally divided intervals according to the count values of the predetermined interval unit counter for movement control and the division unit loop counter. Including a movement control unit for controlling a power system for
The movement control unit performs movement control so as to press the image forming unit against one end of the moving range, and according to an interval from a state where the image forming unit is pressed against the end to a position where the image forming unit is stopped thereafter. The image forming apparatus according to claim 1, wherein the count value in the equally divided interval unit is acquired as reference position recognition processing information.   The control unit is configured such that a count value of the division unit loop counter at a position where the image forming unit is stopped after being pressed against the end portion is equal to the division unit loop in a state where the image forming unit is pressed against the end portion. When the count value is smaller than the count value of the counter, the count value of the division unit loop counter returns to the initial value at least once during the period from when the image forming unit is pressed against the end until the stop. The image forming apparatus according to claim 1, wherein the image forming apparatus is determined as follows.   The control unit acquires a count value of the division unit loop counter in a state in which the image forming unit is pressed against the end portion, and the value of the image forming unit recognized in the equally divided interval unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is subtracted from a value indicating a position.   In the control unit, the position of the image forming unit that is recognized by the equally divided interval becomes an extreme value from the state in which the image forming unit is pressed against the end portion until the stop thereafter. 5. The image formation according to claim 4, wherein a count value of the division unit loop counter at the time is acquired as a count value of the division unit loop counter in a state where the image forming unit is pressed against the end portion. apparatus.   The control unit adds the value corresponding to the range of values that the division unit loop counter loops to the count value indicated by the reference position recognition processing information, so that the converted count value is counted by one extra count. 6. The image forming apparatus according to claim 1, wherein the image forming apparatus corrects the value so as to obtain a corrected value.   The control unit stops the movement control of the image forming unit when it is detected that the image forming unit is pressed against one end of the moving range, and the equally divided interval unit after a predetermined period has elapsed. 7. The image forming apparatus according to claim 1, wherein the position of the image forming unit recognized in step S <b> 1 is acquired as the reference position recognition processing information.   The control unit confirms that the image forming unit is pressed against one end of the moving range when the position of the image forming unit recognized by the equally divided interval unit is constant for a predetermined period. The image forming apparatus according to claim 7, wherein the image forming apparatus is detected. A control method of an image forming apparatus that performs image formation output while moving an image forming unit relative to an object,
The image forming apparatus includes:
A predetermined interval unit counter that counts signals output in response to movement of the image forming unit at predetermined intervals;
A division unit loop counter that counts a signal that is output in accordance with movement of the image forming unit at intervals of which the predetermined interval is equally divided by a value that loops at the predetermined interval;
In accordance with the count values of the predetermined interval unit counter and the division unit loop counter, the position of the image forming unit is recognized in the equally divided interval units, and overall control relating to the image forming output operation is performed.
The movement is controlled so as to press the image forming unit against one end of the moving range, and the image forming unit is divided equally according to the interval from the state where the image forming unit is pressed to the end to the position where the image forming unit stops thereafter Get the count value in intervals as reference position recognition processing information,
The count value indicated by the reference position recognition processing information is converted from the unit for each equally divided interval to the unit for the predetermined interval, and the converted count value is set in the first predetermined interval unit counter. The count value of the division unit loop counter in a state where the image forming unit is pressed against the end is subtracted from the value indicating the position of the image forming unit recognized in the equally divided interval unit,
If the count value of the division unit loop counter has returned to the initial value at least once during the period from when the image forming unit is pressed against the end portion to when it stops, the count value is divided into equal parts. The count value indicated by the reference position recognition processing information corrected so that the converted count value becomes a value counted by one extra when converting from the unit for each interval to the unit for the predetermined interval Is converted into a unit for each predetermined interval.

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