JP2006067750A - Speed control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten acceleration time at carriage scanning of an ink jet printer. <P>SOLUTION: The time requiring allowable maximum acceleration is provided for the first half of acceleration time. A speed command curve is set so as to smoothly guide acceleration to zero for the second half of the acceleration time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a speed control device represented by a carriage scanning control device of an ink jet serial recording device that is used for office work or industrial use, or used in an information processing apparatus such as a copying machine, a facsimile machine, a word processor, or a computer. .

  The carriage scanning system of the inkjet serial recording device has been changed from open-loop control by "pulse motor" to closed-loop control by "DC motor" and "linear encoder" to meet the demands of "high image quality" and "silence". It changed.

  FIG. 18 is a diagram for explaining the “speed command” of the conventional example. In the closed loop speed control, the “speed command” given to the control device is used in the actual product with respect to the simplest “step speed command” of (a). ”And“ c-curve speed command ”in (c), it is common to consider to eliminate the cause of speed vibration.

In the “S-curve speed command” (c), a cubic or quintic function is used so that the acceleration change obtained by differentiating the speed command curve changes in a mountain shape such that “0 → maximum value → 0”. It is set with a curve. The acceleration curve shown as “acceleration (α) cubic” is a quadratic function curve (parabola), and the acceleration curve shown as “acceleration (α) fifth order” is a quartic function curve (fifth order). The function acceleration curve is proposed in Patent Document 1).
JP 2000-188894 A

  In recent years, ink jet printers are required to shorten the printing time. In the carriage scanning device, the problem is “reduction of scanning time”. In particular, in carriage scanning driving that repeats reciprocation over hundreds of short distances for printing on a single recording sheet, “shortening acceleration time” is important for “shortening scanning time”.

  To put it simply, it is sufficient to use a motor with a large torque, apply a high voltage, flow a large current, and drive the scanning mechanism with a large torque. It is inconvenient because it increases the size. That is, there are limitations on “motor performance”, “applied voltage”, and “allowable current”. Further, since the driving force is transmitted by the belt in the carriage scanning mechanism, if the driving force exceeding the belt initial tension is transmitted, the belt is slackened, and the speed variation of the carriage becomes oscillating. . Further, when the acceleration increases, the rotational vibration (yawing) of the carriage becomes intense, which causes a disadvantage of lowering the print quality. In other words, there is a limit on the “maximum acceleration”.

  The present invention has been made paying attention to the above points, and an object of the present invention is to provide a speed control device that shortens the acceleration time in carriage scanning of an ink jet printer.

  FIG. 19 is a diagram illustrating changes in “speed command value”, “carriage speed”, “carriage acceleration”, “motor current value”, and “PWM value” during acceleration in the conventional example.

  “PWM value” is an operation amount of the motor. Here, “PWM” is “Pulse Width Modulation”, the motor applied voltage is constant, and the pulse width of the applied voltage is changed to change the duty of the applied voltage, thereby increasing or decreasing the voltage in a pseudo manner. It is a technique to make it. This is a method generally used in digital servos by adjusting the current value, controlling the torque generated from the DC motor, and controlling the speed. In this example, the PWM value takes a value from 0 to 1000, and 500 corresponds to 0V. At 0 second, the PWM value starts from 650 instead of 500 (mark (a)). Generally, at the start of speed control, both the proportional term and integral term (speed error accumulated value) of PID control are 0, and the PWM value starts from 500 here. In that case, the motor cannot operate the mechanism until the integral term accumulates the speed error and the PWM value (operation amount) exceeds the friction load of the mechanism to be driven. Is known to produce In this conventional example, a device for eliminating the time lag by setting a predetermined initial value in the integral term and starting the PWM value from 650 has already been incorporated (mark (b)).

  A speed command is given by a cubic function curve so that acceleration is completed in 0 to 0.075 seconds. When the change of the PWM value is observed, the maximum value of the PWM value reaches 940 (marked (c)), and even in this case, 88% of the motor performance (= (940−500) / 500) is requested. It can be said that it is demanding almost the maximum acceleration. However, it should be noted here that the maximum time is around 0.065 seconds.

  By the way, there is a so-called counter electromotive force that increases in proportion to the rotational speed of the motor. Therefore, during high-speed rotation, even if the PWM value is increased, the presence of the counter electromotive force does not increase the effective voltage so much that a flowing current, that is, a generated torque cannot be sufficiently obtained.

  The current takes the maximum value at the time of 0.05 seconds indicated by (d), which is about 1.1 (A), but in 0.065 seconds when the PWM value becomes maximum, 1 (A) It can also be seen from the fact that it is a low value (mark (e)). That is, in this acceleration method, the maximum performance of the motor is required most in the latter half of the acceleration, but the effect is countered by the influence of the counter electromotive force, and the performance of the motor is not fully utilized. Looking at the acceleration of the carriage, the time when the maximum value is taken (marked (f)) is at 0.05 seconds. Before 0.0375 seconds in the first half of acceleration, “PWM value”, “motor current value”, and “carriage acceleration” are all at low levels, the motor rotation speed is low, the back electromotive force is small, and the first half of acceleration Increasing each value is considered to enable "shortening the acceleration time".

  However, applying the maximum PWM value of 1000 in the first half of the acceleration is problematic because it exceeds the “allowable carriage acceleration” due to the convenience of the mechanism and the control device as described above.

  In the present invention, the acceleration command value, which is raised to the maximum value of 17 (m / sec ^ 2), as shown by the mark (g), the carriage acceleration in the first half of acceleration, which remains at a low level in the conventional example, is obtained. suggest.

  FIG. 20 is a schematic diagram illustrating a speed command curve according to one embodiment of the present invention. (A) is a change in required acceleration. In the first acceleration region indicated by (a) from time 0 to Tchange, an allowable acceleration maximum value (αmax) is set to be obtained. In the second half region of acceleration indicated by (b) from time Tchange to Tacc, the acceleration is monotonously decreased so that a smooth transition can be made toward the constant speed command (that is, acceleration 0). The arrival speed is calculated based on the total area S of the two regions. If αmax and the arrival speed are determined, Tchange is automatically determined when Tacc is selected.

(B) is a speed command curve obtained by integrating the acceleration of (A). In the (a) region, it is a linear function with an allowable acceleration maximum value (αmax) in the slope, and in the (b) region,
V = −tan (θ) / 2 × t ^ 2 + a × t
However, it is a quadratic function of V: speed, t: time, tan (θ) = αmax / (Tacc−Tchange), a: constant.

  By applying this speed command curve, smooth acceleration that does not exceed the maximum allowable acceleration and reduced acceleration time can be achieved while maintaining the maximum value of the operation amount (PWM value) to the motor. Is possible.

  Although the details of the present invention have been described above, this will be organized and described below.

  (1) A speed command curve provided in advance to the speed control device of a speed control device that has a mechanism and a drive source for operating the mechanism and functions to cause the operation of the mechanism to reach a target speed. As the required acceleration curve obtained by differentiating the curve, in the first half of the acceleration completion time, as the allowable maximum acceleration required section, set the maximum allowable acceleration that comes from the limitations of the mechanism, drive source, speed control device, etc., in the second half, A speed control apparatus, wherein a monotone decreasing curve leading from a maximum allowable acceleration to an acceleration of 0 is set, and a speed command curve obtained from the required acceleration curve is set.

  According to the present invention, a time for requesting the maximum allowable acceleration is provided in the first half of the acceleration time, and the speed command curve is set so that the acceleration is smoothly guided to 0 in the second half of the acceleration time. Maintains the "maximum acceleration" that increases the load on the system, the "maximum PWM value" that is the input to the motor, the "maximum current value" that burdens the drive circuit, and the "convergence performance to the target speed" In addition, it is possible to realize “reduction of acceleration time”.

  That is, it is possible to provide a comfortable recording apparatus with a shorter printing time without impairing the print quality by controlling improvement without increasing the cost of mechanical parts, electrical parts and the like.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a serial ink jet recording apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view for explaining the configuration of a carriage scanning device of a serial ink jet recording apparatus according to an embodiment of the present invention. FIG. 7 is an external perspective view of an ink jet recording apparatus according to an embodiment of the present invention, FIG. 8 is a perspective view illustrating functions of each part of the ink jet recording apparatus, and FIG. 9 is a longitudinal sectional view of the ink jet recording apparatus. FIG. 10 is an explanatory diagram of the scanning range of the carriage of the ink jet recording apparatus. FIG. 11 is an external view and a partially enlarged view of a BJ cartridge of the ink jet recording apparatus, FIG. 12 is a recovery system unit configuration diagram of the ink jet recording apparatus, and FIG. 13 is a block mainly showing a configuration of an electric part of the ink jet recording apparatus. FIG.

  Hereinafter, an inkjet recording apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 7 to 13.

  In FIG. 7, reference numeral 1 denotes a place where print media are collectively set by a sheet feeder. A sheet guide 2 is placed on the left side of the sheet so that the print medium is fed straight. Reference numeral 4 denotes a discharge port where a medium on which printing has been completed is discharged. 5 can hold up to several tens of printed media on the paper discharge tray. Reference numeral 6 denotes an operation panel in which power buttons, online buttons, and the like are arranged. A front cover 7 is opened when the BJ cartridge 19 (see FIG. 11) is replaced or when a jammed medium is removed.

  In FIG. 8, numeral 8 designates a pickup roller that feeds out the media set on the sheet feeder 1 one by one. Reference numeral 9 denotes a paper feed motor. The driving force generated here is decelerated by a slow-down gear 10 and then transmitted to the paper feed roller 11 to rotate the paper feed roller 11. A pressure roller 12 is a non-driven roller that is in pressure contact with the paper feed roller 11 and is driven. The sheet fed to the position where the paper feed roller 11 and the pressure roller 12 are in contact with each other by the pickup roller 8 is fed from there by the conveying force of the paper feed roller 11. Reference numeral 13 denotes an eject roller that discharges the medium that has been printed by the eject roller to the discharge tray 5. Reference numeral 14 denotes a spur, which plays a role of pressing the medium against the eject roller 13, and its shape is undetermined after printing. It is devised so that the ink of wearing does not adhere.

  Reference numeral 19 denotes a BJ cartridge having a recording head and an ink tank.

  Reference numeral 151 denotes a carriage, which is a component on which the BJ cartridge 19 is mounted, and is configured so that it can be easily attached and detached. Reference numeral 20 denotes a guide shaft, and 21 denotes a guide rail, which supports the posture of the carriage 151.

  A DC motor is used as the carriage motor 152.

  A carriage belt 155 is stretched by a drive pulley 153 and an idler pulley 154 that are directly connected to the carriage motor 152.

  A linear encoder scale 156 is fixedly stretched on the printer chassis and can detect position information of the carriage 151 by a linear encoder sensor 157 (see FIG. 13) mounted on the carriage 151.

  Since the carriage 151 is fixed at one position of the carriage belt 155, the BJ cartridge 19 performs a main scanning operation by the driving force generated by the carriage motor 152 (details of the carriage driving device will be described with reference to FIG. 1).

  A recovery system unit 22 includes a cap 23 that prevents the print head from drying when the printer is not used, and a pump 24 that applies a negative pressure to the print head and sucks ink in the print head through the cap 23. A blade 25 is provided for wiping the recording head surface that is soiled by printing (23, 24, and 25 are described in FIG. 12).

  In FIG. 1, the carriage belt 155 is stretched with sufficient tension by a drive pulley 153 and an idler pulley 154 directly connected to the carriage motor 152 (arrow B). The guide shaft 20 guides the carriage 151 to scan in the arrow A direction. On the linear encoder scale 156, marks provided at equal intervals at 360 lpi (line per inch, = 25.4 mm / 360 = 70.6 μm) are printed, and 157 linear encoder sensors fixed to the carriage 151 are used. By detecting, the position of the carriage 151 can be obtained accurately. Further, when scanning the carriage 151, the carriage speed can be calculated from the time interval of the encoder signal.

  In FIG. 9, a plurality of print sheets 45 stacked on the sheet feeder 1 are sent to the position of the paper feed roller 11 by the pickup roller 8 rotating twice. At this time, the pickup flag 42 provided on the pickup roller 8 blocks the pickup roller sensor 46 which is a photo sensor, thereby informing the control board 111 (see FIG. 13) of the state. Thereafter, as described above, the sheet is conveyed by the pressure roller 12 and the paper feed roller 11. A transmission roller 44 transmits the drive of the paper feed roller 11 to the 13 ejection rollers. A BJ cartridge 19 is arranged around the top of the transmission roller 44, which is a printing area. Then, the printed paper is discharged by the functions of the spur 14 and the eject roller 13. The paper end flag 43 is arranged on the upstream side of the paper feed roller 11, and when there is paper, the paper end sensor 41 is shut off and the control board 111 is notified of it. When the trailing edge of the sheet deviates from the position of the paper end flag 43, the control board 111 forcibly executes printing of a predetermined line from the paper end sensor 41 based on the information from the paper end sensor 41 regardless of the presence or absence of data at that time. Eject the paper.

  The carriage 151 is fixed to a part of the carriage belt 155. A linear encoder sensor 157 fixed to the carriage 151 detects a mark on the linear encoder scale.

  The allocation within the entire scanning range of the carriage will be described with reference to FIG.

  Most of the “all scanning range” D is a “recording operation area” D1. In this region D1, the carriage can stably travel at a predetermined speed, and printing is executed by ejecting ink droplets from the mounted recording head while scanning within a constant speed fluctuation range.

  On both sides of the print area, there are “acceleration / deceleration areas” D2 and D3. When printing in the “recording operation area” D1 full width, the acceleration / deceleration areas D2 and D3 complete acceleration to a predetermined speed and deceleration for reversing the scanning direction.

  The “wiping area” D4 is an area in which a blade in a recovery system unit, which will be described later, and the nozzle formation surface of the recording head come into contact with each other to perform the operation of removing the attached ink droplets. Preliminary ejection is also performed in this region.

  The recording head is covered and protected by the cap 23 in the recovery system. At that time, the carriage 151 needs to be in the “home position” P at the right end in the drawing. Further, after the end operation when the power is turned off, the carriage is set at the “home position” P.

  FIG. 11 is an external perspective view (A) of the BJ cartridge 19 and an enlarged view (B) of the recording head unit. The BJ cartridge 19 includes an ink tank 19a and a recording head 19b. The cartridge includes four color ink tanks of black, cyan, magenta, and yellow and is capable of full color printing. The recording head portion 19b is provided with a nozzle row 19c. From this point, ink droplets are ejected and recording is performed on the paper. Reference numeral 19d denotes a head face surface forming a nozzle. As shown in the enlarged view of the nozzle portion (C), the nozzle rows 19c are arranged in a row, and the interval is 1/720 inch, about 35.3 μm. A total of 320 nozzles are formed, No1 to 128 are black, No145 to 192 are cyan, No209 to 256 are magenta, and No273 to 320 are yellow nozzles.

  Nos. 129 to 144, Nos. 193 to 208, and Nos. 257 to 272 are dummy nozzles. Although these nozzles are formed, the ink supply path is not connected to the ink tank. When wiping, the phenomenon that the ink of the adjacent color adhering to the head face surface enters the nozzle is reduced.

  In this embodiment, when the ejection state of the BJ cartridge 19 deteriorates, the 320 nozzles described above are covered with one cap 23, and the inside of the cap 23 is decompressed, so that ink is sucked simultaneously from all the nozzles.

  Reference numeral 19d denotes a head face surface forming the nozzle row 19c. As shown in FIG. (B), the head face surface 19d is substantially flat, and the cap 23 is brought into pressure contact with the nozzle row 19c so as to cover it, thereby sucking ink.

  FIG. 12 is a configuration diagram of the recovery system unit 22.

  FIG. 1A is a top view of the configuration. 23 is a cap, 26 is a cap holder that supports the cap 23, and 24 is a pump. Reference numeral 25 denotes a blade. If the carriage 151 scans on the recovery system unit in the state shown in the drawing, wiping is performed. It is slidable in the direction indicated by the arrow and retracts when wiping is not required. Reference numeral 31 denotes a recovery motor, which is a vertical movement of the cap 23, a sliding movement of the blade 25, and a drive source of the pump 24.

  FIG. (B) is a cross-sectional block diagram seen from the direction of arrow A in FIG. The cap 23 is pressed against the recording head portion of the BJ cartridge 19. The cap holder 26 is supported so as to be rotatable about a fulcrum. A cap spring 27 applies a pressure contact force to the cap 23 via the cap holder 26. Reference numeral 28 denotes a cap releasing cam which is rotated 180 degrees from the state shown in the drawing to press the cap holder 26 and release the pressure contact of the cap 23.

  Reference numeral 29 denotes a tube, which is connected to the cap 23 via a pipe portion provided in the cap holder 26. The tube 29 passes through the pump 24 and constitutes a pump generally called a tube pump. Reference numeral 30 denotes a pump roller, which rotates in the direction of the arrow d, thereby squeezing the tube 29, lowering the pressure in the connected cap 23, and sucking out the ink in the BJ cartridge 19.

  In FIG. 13, reference numeral 111 denotes a control board that controls each part of the apparatus. Reference numeral 100 denotes an MPU that receives a signal from each unit and issues a control signal to each unit according to the signal to control the entire apparatus. 101 is a ROM storing a control procedure program, 102 is a RAM used as a work area at the time of execution of control, 103 is a timer for measuring time, 104 is non-volatile data to be stored such as the cumulative number of recordings, waste ink amount, etc. Holding means (EEPROM, etc.), 105 is an interface unit for exchanging signals with a host such as a computer, 106 is an indicator unit for notifying the user of the status of the apparatus, 107 is a user switch including a power switch, online switch, etc. Is a key switch operated to give a command to this apparatus, and 108 is a carriage motor driver for driving the carriage motor 152. The ON / OFF duty is changed, and a voltage having a pulse width suitable for the state is applied to the motor. give. The signal detected by the linear encoder sensor 157 is passed to the MPU, the scanning speed of the carriage 151 is calculated, and used for speed control and position control of the carriage motor 152. A paper feed motor driver 109 drives the paper feed motor 9, a recording head driver 110 drives the recording head, and a recovery motor driver 112 drives the recovery motor 31.

  FIG. 14 is a block diagram showing an example of the scanning speed control system of the carriage scanning device of the ink jet recording apparatus according to the embodiment of the present invention. The closed loop speed control system will be described. In the closed loop control, a detection unit for notifying the control circuit of speed information to be controlled is necessary. In this example, a linear encoder sensor 157 is used.

  A linear encoder sensor 157 mounted on the carriage 151 detects a mark printed on a transparent linear encoder scale 156 fixedly stretched over the scanning range of the carriage. The position can be detected by counting the number of marks, and the speed is calculated from the time interval of continuous detection of marks.

  Further, the speed conversion circuit calculates the current “scanning speed value” of the carriage 151 from the signal of the linear encoder sensor 157 and a clock built in the printer.

  The numerical value obtained by subtracting the “scanning speed value” from the “speed command value” is transferred to the “PID calculation circuit” as a “speed error” that is insufficient with respect to the target speed, and the energy to be given to the DC motor there is “PID calculation” (The PID calculation will be described with reference to FIG. 15). Receiving this, the “carriage motor driver 108” gives an input to the DC motor by PWM control and performs speed control.

  The rotational torque generated in the carriage motor 152 is transmitted to the carriage 151 via the directly connected drive pulley 153 and carriage belt 155, and is driven to scan.

  According to the above method, the necessary torque is generated from the motor when necessary, and the scanning speed can be controlled to a constant value regardless of a change in the sliding load of the carriage.

  FIG. 15 is an explanatory diagram of a carriage scanning speed control system PID calculation unit according to an embodiment of the present invention. The passed speed error values are calculated through paths called Proportional, Integral, and Differential, respectively, and are summed.

In proportional, the speed error is multiplied by Gp.
In Integral, the speed error is integrated (that is, accumulated), and the integrated value is multiplied by Gi.
In the differential, the speed error is differentiated (that is, the difference from the previous speed error value is calculated), and the differential value is multiplied by Gd.

  The total value is further multiplied by the overall gain G and delivered to the motor driver.

  Hereinafter, the speed command given to the speed control of one embodiment of the present invention and the effect thereof will be described with reference to FIGS.

  FIG. 2 is an explanatory diagram for the differentiation of the speed command value according to the embodiment of the present invention. This compares the acceleration required by the speed command curve between the conventional example and the example. It can be seen that the maximum value of acceleration is limited to 17 (m / sec ^ 2), which exceeds 18 (m / sec ^ 2). The time (Tchange) for finishing the maximum acceleration request is set to 0.045 seconds. It can be seen that the acceleration completion time (Tacc) is 0.065 seconds, 0.01 seconds earlier than the conventional example of 0.075 seconds. The acceleration completion time is advanced by requiring a large acceleration in the early stage of acceleration.

  FIG. 3 is an explanatory diagram of the speed command value and the carriage speed value according to the embodiment of the present invention.

  Since the speed command value requires the maximum acceleration from the initial stage of acceleration, it can be seen that the time for requesting the same speed is advanced by about 0.01 seconds as indicated by the mark (a).

  It can be seen that the carriage speed, which is the control result, is also accelerated by about 0.01 seconds, as indicated by the mark (b). Furthermore, it should be noted that although the acceleration time was shortened, the smooth convergence to the target speed was not deteriorated and maintained at the same level.

  FIG. 4 is an explanatory diagram of a change in carriage acceleration according to an embodiment of the present invention.

  The maximum acceleration value is held at a somewhat lower level from 17 (m / sec ^ 2) to 16 (m / sec ^ 2), as indicated by the mark (a). The acceleration at the initial stage of acceleration is raised to the 16 (mm / sec ^ 2) level as indicated by the mark (b), and the 16 (mm / sec ^ 2) level is increased from 0.01 seconds to 0.05 seconds. It can be seen that it continues for 04 seconds as indicated by the mark (c). Further, as shown in (d), the timing at which the acceleration becomes almost zero is also advanced by about 0.01 seconds. From this, it can be seen that even if printing is started at an early timing, the print quality is not adversely affected.

  FIG. 5 is an explanatory diagram of a change in PWM value in motor control at a speed according to an embodiment of the present invention. As shown in (a), the maximum PWM value is at the same level as about 940. As shown in (b), the approximate shape is not changed except that it is generally shifted to the control start direction by about 0.01 seconds.

  FIG. 6 is an explanatory diagram of a change in motor current value at a speed according to an embodiment of the present invention. As shown by (a), the maximum motor current value is kept somewhat low from 1.12 (A) to 1.08 (A). As shown in (b), the motor current value at the initial stage of acceleration is increased, and as shown in (c), the timing at which the current value decreases is advanced.

[Other Example 1]
In this embodiment, the carriage scanning mechanism control device of the ink jet recording apparatus for a personal computer has been described. However, the gist of the present invention is not limited to this.

  For example, a scanning mechanism control device for an industrial printing device or processing device may be used in one direction.

[Other Example 2]
In the present embodiment, the drive source has been described as a general motor, that is, a rotary motion body, but the gist of the present invention is not limited to this.

  For example, an electromagnetic induction type or ultrasonic drive type linear motor may be used.

[Other Example 3]
In this embodiment, the DC motor has been described as a drive source, but the gist of the present invention is not limited to this.

  An ultrasonic motor, an AC motor, a pulse motor, or the like may be used.

[Other Example 4]
Although the present embodiment has been described as closed loop control by PID control, the gist of the present invention is not limited to this.

  Even open-loop control is acceptable.

[Other Example 5]
In this embodiment, the carriage scanning speed detection means is described as a linear encoder sensor mounted on the carriage, but the gist of the present invention is not limited to this.

  For example, a laser Doppler type speed detector fixed to a printer chassis or a rotary encoder attached to a motor shaft may be used.

[Other Example 6]
In the present embodiment, the configuration of the pulley has been described as a drive pulley and two idler pulleys, but the gist of the present invention is not limited to this.

For example,
"Drive pulley 1 and 2 idler pulleys"
"Drive pulley 1 and 3 idler pulleys"
Various cases are possible, and any combination is acceptable.

[Other Example 7]
FIG. 16 is a first diagram illustrating changes in acceleration for determining a speed command value according to another embodiment of the present invention.

  In the present embodiment, the change in acceleration in the area leading to acceleration 0 following the area requiring the maximum acceleration up to Tchange has been described with a straight line as shown in (a), but the gist of the present invention is limited to this. Is not to be done. Even if it is a curve like (b) and (c), it does not matter.

[Other Example 8]
FIG. 17 is a second diagram for explaining a change in acceleration in order to determine a speed command value according to another embodiment of the present invention.

  In the present embodiment, it has been described that a constant acceleration is required as shown in (a) in the region where the maximum acceleration up to Tchange is required, but the gist of the present invention is not limited to this. If the Tchange time is long and the speed increase during that time is large, the required acceleration may need to be gradually reduced as shown in (b) in view of the influence of the back electromotive force of the motor described above. is there. The present invention also proposes acceleration request setting in such a case.

1 is a perspective view illustrating the configuration of a carriage scanning device of a serial ink jet recording apparatus according to an embodiment of the present invention. Explanatory drawing about differentiation of speed command value of one embodiment of the present invention Explanatory drawing of speed command value and carriage speed value of one embodiment of the present invention Explanatory drawing of the carriage acceleration change of one Example of this invention Explanatory drawing of PWM value change of motor control of one embodiment of the present invention Explanatory drawing of motor current value change of speed of one embodiment of the present invention 1 is an external perspective view of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a perspective view illustrating functions of each part of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a longitudinal sectional view of an ink jet recording apparatus according to an embodiment of the present invention. Explanatory drawing of the scanning range of the carriage of the inkjet recording apparatus of one Example of this invention FIG. 1 is an external view and a partially enlarged view of a BJ cartridge of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 1 is a configuration diagram of a recovery unit of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a block diagram mainly showing a configuration of an electric part of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a block diagram illustrating an example of a scanning speed control system of a carriage scanning device of an ink jet recording apparatus according to an embodiment of the present invention. Explanatory drawing of the carriage scanning speed control system PID calculating part of one Example of this invention The figure explaining the change of acceleration in order to determine the speed command value of the other Example of this invention (the 1) The figure explaining the change of acceleration in order to determine the speed command value of the other Example of this invention (the 2) A diagram explaining the "speed command" of the conventional example The figure explaining the change of "speed command value" "carriage speed" "carriage acceleration" "motor current value" "PWM value" at the time of acceleration of a prior art example The schematic diagram explaining the speed command curve of one Example of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet feeder 2 Sheet guide 4 Paper discharge outlet 5 Paper discharge tray 6 Operation panel 7 Front cover 8 Pickup roller 9 Paper feed motor 10 Slow down gear 11 Paper feed roller 12 Pressure roller 13 Eject roller 14 Spur 19 BJ cartridge 20 Guide shaft 21 Guide rail 22 Recovery system unit 23 Cap 24 Pump 25 Blade 26 Cap holder 27 Cap spring 28 Cap release cam 29 Tube 30 Pump roller 41 Paper end sensor 42 Pickup flag 43 Paper end flag 44 Transmission roller 45 Printing paper 46 Pickup roller sensor 100 MPU
101 ROM
102 RAM
103 Timer 104 Non-volatile data holding means (EEPROM, etc.)
105 Interface unit 106 Indicator unit 107 Key switch 108 Carriage motor driver 109 Paper feed motor driver 110 Recording head driver 111 Control board 112 Recovery system motor driver 151 Carriage 152 Carriage motor 153 Drive pulley 154 Idler pulley 155 Carriage belt 156 Linear encoder scale 157 Linear Encoder sensor

Claims (8)

In a speed command curve given in advance to the speed control device of a speed control device having a mechanism and a drive source for operating the mechanism and functioning to reach the target speed.
As the required acceleration curve obtained by differentiating the speed command curve, in the first half of the acceleration completion time, as the allowable maximum acceleration required section, set the maximum allowable acceleration resulting from the limitations of the mechanism, drive source, speed control device, etc.
In the second half, set a monotonically decreasing curve that leads from the maximum allowable acceleration to zero acceleration,
A speed control device, wherein a speed command curve obtained from the required acceleration curve is set.   The speed control apparatus according to claim 1, wherein the mechanism is a reciprocating scanning mechanism.   The speed control apparatus according to claim 2, wherein the driving source rotationally drives a DC motor, an ultrasonic motor, an AC motor, a pulse motor, or the like.   4. The speed control apparatus according to claim 3, wherein the speed control apparatus is a carriage scanning control apparatus for a serial recording apparatus.   The carriage is coupled to a belt, and the driving source has a driving pulley directly on a rotating shaft, and the belt is stretched with a predetermined tension by at least one idler pulley to rotate the belt. The speed control apparatus according to claim 4, further comprising a mechanism for reciprocally scanning the carriage.   The speed control apparatus according to claim 5, wherein the speed control is a closed loop speed control.   The speed control apparatus according to claim 6, wherein the speed detection means for giving speed information to the closed loop speed control is an encoder sensor.   8. The speed control apparatus according to claim 7, wherein the required acceleration curve that leads to an acceleration of 0 in the latter half region of acceleration is a linear decrease.