JP2001334717A - Method for controlling recording and device for recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling a recording a device for recording which enhances the total throughput without excessively increasing a speed for transporting a paper and enables the speed for transporting the paper apparently to be zero. SOLUTION: A main scanning in the opposite direction starts immediately after one scanning of forward or backward moving of a carriage is completed. The scanning of the carriage is performed by controlling a motor for the main scanning one after another in an acceleration zone, a constant velocity zone and a deceleration zone. A sub scanning for transporting the paper is performed in the total zone of the deceleration zone of one scanning and the acceleration zone of the next scanning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus such as a printer or a plotter which records an image on a recording sheet conveyed in a direction substantially orthogonal to the carriage moving direction by a carriage mounted with a recording head and moving. In particular, the present invention relates to a recording control method.

[0002]

2. Description of the Related Art Conventionally, in a recording control apparatus of this kind, when recording an image portion corresponding to a recording head width (one band) by moving a carriage, the paper is stopped in order to maintain recording quality. Therefore, the movement of the carriage and the conveyance of the sheet are performed alternately. In order to improve the total recording throughput (time reduction) under such conditions, it is necessary to improve the moving speed of the carriage and the recording speed of the recording head, and also the transport speed of the paper. In particular, when printing is performed on both the forward path and the return path of the movement of the carriage, quick and reliable transport of the sheet greatly contributes to the improvement of the total throughput.

Therefore, with respect to paper transport for improving the total throughput, conventionally, the paper transport speed after one scan of the carriage is increased to the upper limit.

[0004]

However, in order to shorten the transport time by increasing the paper transport speed after one scan of the carriage to increase the throughput, the top speed and acceleration / deceleration of the sub-scanning motor for transporting the paper are increased. As a result, the mechanical accuracy of the paper transport mechanism (paper slip during acceleration, variation in the stop position due to backlash during deceleration stop) needs to be improved, and the motor needs to be upgraded, resulting in an increase in cost. was there.

Accordingly, it is an object of the present invention to provide a recording control method and apparatus capable of improving the total throughput without excessively increasing the paper transport speed.

Another object of the present invention is to provide a recording control method and apparatus which can apparently reduce the paper conveyance speed to zero.

[0007]

According to the present invention, there is provided a recording control method comprising a recording head mounted on a sheet conveyed in a sub-scanning direction substantially orthogonal to the main scanning direction by a carriage reciprocating in the main scanning direction. A printing control method in a printing apparatus for performing bidirectional printing on a forward path and a return path of a carriage, wherein a main scan in the opposite direction is started immediately after one scan of the forward path or the return path of the carriage is completed, and the scanning of the carriage is performed by the main scan. The motor is sequentially controlled in an acceleration section, a constant speed section, and a deceleration section, and the sub-scan is executed during a total section of the deceleration section of one scan of the carriage and the acceleration section of the next scan.

As described above, the sub-scanning is performed during the total section of the deceleration section of one scan of the carriage and the acceleration section of the next scan, so that the required paper transport time is included in the required carriage movement time. The paper transport speed can be apparently reduced to zero. In addition, by using the total section of the deceleration section of one scan of the carriage and the acceleration section of the next scan for the sub-scan, the total throughput can be improved without excessively increasing the sheet conveyance speed.

Preferably, the carriage is moved by a majority of the moving distance of the sub-scan in the deceleration section of the total section of the deceleration section of one scan and the acceleration section of the next scan. As a result, a stop period of the sub-scanning motor occurs before the start of recording in the next scan, and the operation of the sheet transport mechanism can be settled.

[0010] A recording apparatus that implements the above recording control method includes:
A carriage mounted with a recording head and reciprocating in the main scanning direction, a main scanning motor for controlling the movement of the carriage, a sub-scanning motor for conveying recording paper, and a main scanning motor and a sub-scanning motor. Motor control means for controlling each according to the movement trajectory of acceleration, constant velocity, and deceleration by servo feedback control; trajectory calculation means for calculating the movement trajectory prior to one main scan and one sub-scan, respectively; Deceleration point monitoring means for monitoring the arrival of a deceleration point in one scan by servo feedback control of the main scanning motor, and activating the sub-scanning by the sub-scanning motor when detecting the arrival of the deceleration point; Is performed within a total section of a deceleration section of one scan of the carriage and an acceleration section of the next scan.

According to this apparatus, the same operation and effect as those of the recording control method can be obtained.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, as an example of the recording apparatus to which the present invention is applied, a recording apparatus of an ink jet recording method is described, but the present invention is not limited to the ink jet recording method.

FIG. 1 shows a schematic configuration of a recording apparatus of an ink jet recording system to which the present invention is applied.
Recording heads 101Bk, 101Y, 101M, 101C
Are mounted on a carriage 106, and black, yellow, magenta, and cyan inks are supplied from an ink tank (not shown) via an ink tube.
Recording heads 101Bk, 101Y, 101M, 101C
The ink supplied to the printer is driven by a print head driver or the like in accordance with a print signal corresponding to print information from a main control unit (not shown), and ink droplets are ejected from each print head 101 to print on the paper 102. Is made.

A sub-scanning motor (paper transport motor) 103 is a drive source for intermittently feeding the paper 102 and drives a transport roller 104. The sub-scanning motor 103 is provided with an encoder 8 for position management in the sub-scanning direction. The main scanning motor 105 is a driving source for scanning the carriage 106 on which the recording head 101 is mounted in the directions of arrows A and B via a main scanning belt 107.
When the paper 102 is fed and conveyed by a paper feed mechanism of the main body and a conveying roller 104 (not shown) and reaches a recording position, the sub-scanning motor 103 is turned off, and the feeding of the paper 102 is stopped. Prior to the image recording operation on the paper 102,
The carriage 10 is located at the position of the home position sensor 108.
Then, forward scanning is performed in the direction of arrow A, and black, yellow, magenta, and cyan inks are ejected from the predetermined positions from the recording heads 101Bk to 101C to perform image recording. When the image recording for one band is completed, the carriage 106 is stopped, and conversely, the backward scanning is started in the direction of arrow B. During the backward scanning, the recording heads 101Bk to 10
By driving the sub-scanning motor 103 by the length recorded at 1C, the paper 102 is conveyed in the direction of arrow C. By repeating such a head scanning operation and a paper feeding operation, recording of the entire image is realized.

The linear scale 109 has a high-resolution slit, which can be read by a transmission type optical sensor (not shown) mounted near the carriage 106 to obtain two phase signals. it can.
The position of the carriage 106 is managed based on this signal, and the ink ejection of the recording head 101 is synchronized. In the present embodiment, it is possible to record at 1200 dots / inch based on the signal obtained from the linear scale 109.

FIG. 2 is a block diagram showing a configuration example of the main control unit. In FIG. 1, reference numeral 1 denotes a central processing unit (CPU) for controlling the entire system. The CPU 1 includes a ROM 11 storing the control program and fixed data,
RAM 1 that provides a work area and a temporary storage area for CPU 1
In addition to 2, a timer 13 is incorporated. Reference numeral 2 denotes a control ASIC (Application Specific Integrated Circuit) as a part of motor control means for performing motor control under the CPU 1.
t). Reference numeral 4 denotes a main scanning motor (CR motor) for moving the carriage 106, and reference numeral 3 denotes an H-bridge type CR driver for driving the CR motor 4. Reference numeral 6 denotes a sub-scanning motor (LF motor) for driving the transport system, and reference numeral 5 denotes an H-bridge type LF driver for driving the LF motor 6. Reference numeral 7 denotes a CR encoder as a linear encoder that extracts a signal based on a linear scale used for feedback control of the CR motor 4. Reference numeral 8 denotes an LF encoder that is used for feedback control of the LF motor 6 and is a rotary encoder associated with the LF motor 6.

The CR motor 4 and the LF motor 6 in the present embodiment are both DC motors (DC motors), and the control ASIC 2 receives the control signal from the CPU 1 and controls the CR driver 3 and the LF driver 5. At that time,
The servo feedback control for driving the motor is executed while counting the output signals from the CR encoder 7 and the LF encoder 8 and confirming the movement amount of the motor.

When the power is turned on, the CR motor 4 and the LF motor 6
Is in a standby state, for example, at the left end of the timing chart of FIG.

Thereafter, when a movement command is received, first, the CPU 1
Calculates the movement trajectory of the CR motor 4 and the LF motor 6, and finds the distance in each of the acceleration, constant velocity, and deceleration sections. This distance is converted into the count number (pulse number) of the output signal of the CR encoder 7 for the CR motor 4 and the count value (pulse number) of the output signal of the LF encoder 8 for the LF motor 6.

The control trajectory of the motor is represented by a trapezoidal trajectory with the horizontal axis representing time t and the vertical axis representing velocity V as shown in FIG. From the start to the stop of the motor, the motor accelerates from the state of the speed 0 to the maximum speed Vtop in the acceleration section on the left side of the trapezoid, maintains the maximum speed in the constant speed section, and then reduces to the speed 0 in the deceleration section. In the trajectory calculation, the start position (current position) StartP, the target position FinalP, and the acceleration / deceleration acceleration A
The points P1 and P2 are obtained based on cc and the maximum speed Vtop. That is, the number of pulses from the start position to the point P1, the number of pulses in the constant velocity section, and the number of pulses in the deceleration section are obtained. In addition, in each section of acceleration, constant velocity, and deceleration, position data to be given to the servo control is generated for each predetermined timer cycle. Note that the target position FinalP differs between the forward path and the return path, and also differs depending on the image data to be recorded.

The control ASIC 2 is controlled so that the CR motor 4 is moved forward based on the acceleration, constant velocity, and deceleration position data obtained based on the calculation result.

Thereafter, the moving distance of the CR motor 4 is set at a position (referred to as a deceleration point) P at which deceleration is started based on the calculation result.
When two points have been reached, that is, when all the position data in the constant velocity section have been processed, the LF motor 6 is started and moved in a locus of acceleration, constant velocity, and deceleration based on the above calculation.

The time relationship at this time is t3 <t1 + t
It becomes 2. Here, t1 and t2 are CR motors 4 respectively.
Is the time of the deceleration section in a certain scan and the acceleration section in the next scan, and t3 is the total operation time of acceleration, constant speed, and deceleration of the LF motor 6. Typically, t1 and t2 are about 150 ms, and t3 is assumed to be less than 200 ms. The reason for setting t3 <t1 + t2 is to take into consideration the time required for stabilizing the mechanical fluctuation of the sheet transport mechanism until the start of recording in the constant speed section in the next main scan. As a result, in one sheet conveyance, (1 / n) × (total conveyance amount) of the total conveyance amount is conveyed in the deceleration section of the main scanning, and the rest is conveyed in the acceleration section. Here, (1 / n)> (1/2).

Thereafter, the CR motor 4 is controlled in the same way as in the forward movement, and is moved in the backward movement to complete the first reciprocal printing operation.
The same control as above is performed between the return path of the first reciprocal printing operation and the outward path of the second reciprocal printing operation.

As described above, by using the total section of the deceleration section and the acceleration section of the CR motor 4 for driving the LF motor 6, the CR motor 4 is driven for driving the LF motor 6.
It is not necessary to provide a stop section for the above. That is, FIG.
As shown in (a), it is possible to shift to the acceleration section of the next main scan immediately after the end of the deceleration section of one main scan. The driving of the LF motor 6 is performed as shown in FIG.
Since it is completed within the deceleration section and the acceleration section of the R motor 4, the time required for paper feeding can be substantially reduced to zero. Thereby, the recording throughput can be improved.

Although the driving of the LF motor 6 may be performed only in the deceleration section, it is necessary to increase the maximum speed Vtop of the LF motor 6 more than necessary, which leads to an increase in cost. By using both the deceleration section and the acceleration section as in the present embodiment, the maximum speed V of the LF motor 6 can be increased.
There is no need to raise the top excessively.

FIG. 5 is a functional block diagram relating to control of main scanning and sub-scanning in the present embodiment. This control is performed by the servo management module 51 that performs the trajectory calculation processing.
And a servo feedback module 52 for performing servo feedback control of the CR motor 4 and the LF motor 6
Point monitoring module 53 for monitoring the deceleration point P2
Consists of The servo management module 51 calculates the acceleration Ac
Receiving the command value including c, the maximum speed Vtop, the target position FinalP, and the current position StartP, the trajectory calculation processing as described above is performed, and after the processing is completed, the servo feedback module 52 is activated. The servo feedback module 52 that has received this activation,
The main scanning is performed, and the operation of the main scanning is controlled at a predetermined timer period T (for example, 300 μs). The deceleration point monitoring module 53 monitors the arrival of the deceleration point P2 at the timer period 2T, and activates the sub-scanning of the servo feedback module 52 when the arrival of the deceleration point P2 is detected. In response to this, the servo feedback module 52 starts the sub-scan for paper conveyance, and controls the operation of the sub-scan at the timer period T.

FIG. 6 is a flowchart showing a processing example of the deceleration point monitoring module 53. This process is started at the timer period 2T, and after the main scanning is started (S11, Y
es) It is determined whether the main scanning by the servo feedback module 52 has reached the deceleration point P2 (S12).
If it has reached, it is determined whether or not acceleration data for the next main scan is prepared (S13). If it is prepared, the sub-scan is started for the servo feedback module 52 (S14). If not, the sub-scan is started after waiting for a predetermined time T (μs) (S1).
5). The trajectory calculation for a certain scan needs to be completed before the start of the scan.
Due to a change in the processing load of the PU or the like, main scan acceleration data may not be prepared before the start of the next main scan. Steps S13 and S15 take such a case into consideration.

By the way, in a recording apparatus of the ink jet recording system, one band corresponding to the width of the recording head is recorded in a plurality of main scanning passes (for example, two passes, four passes, eight passes) for the purpose of improving recording quality and the like. Multi-pass printing may be performed. In such a case, the paper transport distance in one sub-scan becomes smaller as the number of passes increases (for example, in the case of four passes, it becomes 1/4). Therefore, the restriction on the motor drive speed for sub-scanning is eased. Therefore, in another embodiment of the present invention, the maximum speed LFVtop of sub-scanning is made variable according to the number of passes of multi-pass printing. That is, the larger the number of passes, the smaller the maximum speed LFVtop of sub-scanning. As a result, effects such as improvement of mechanical accuracy (position accuracy), reduction of abuse of the sub-scanning motor, extension of life, suppression of power consumption, suppression of noise generation, and the like can be obtained.

Although the preferred embodiments of the present invention have been described above, it will be apparent to those skilled in the art that various modifications and changes can be made.

[0031]

According to the present invention, the main-scanning motor and the sub-scanning motor are controlled so that the sheet is conveyed in the total section of the deceleration section of the first scan of the carriage and the acceleration section of the next scan. As a result, the maximum control margin of the sub-scanning motor can be increased without excessively increasing the maximum speed, and the total throughput can be improved.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration of an inkjet recording type recording apparatus to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration example of a main control unit of the recording apparatus in FIG. 1;

FIG. 3 is a graph showing a locus of movement of a DC motor according to the embodiment of the present invention.

FIG. 4 shows a CR motor and an LF according to the embodiment of the present invention.
FIG. 4 is a diagram illustrating a movement trajectory that associates a movement operation of a motor.

FIG. 5 is a functional block diagram relating to control of main scanning and sub-scanning in the embodiment of the present invention.

FIG. 6 is a flowchart illustrating a processing example of a deceleration point monitoring module illustrated in FIG. 5;

[Explanation of symbols]

 1. CPU 2. Control ASIC 3. CR driver 4. CR motor 5. LF driver 6. LF motor 7. CR encoder 8. LF encoder 11. .ROM 12 ... RAM 13 ... timer

Claims (4)

[Claims] A carriage mounted with a recording head and reciprocated in a main scanning direction performs bidirectional recording of the carriage in a forward path and a return path on a sheet conveyed in a sub-scanning direction substantially orthogonal to the main scanning direction. A printing control method for a printing apparatus, comprising: starting a main scan in the opposite direction immediately after one scan of a forward pass or a return pass of a carriage is completed, wherein the carriage scans the main scan motor in an acceleration section, a constant velocity section, and a deceleration section. A printing control method, wherein the sub-scanning is performed sequentially during a total section of a deceleration section of one scan of the carriage and an acceleration section of the next scan. 2. The method according to claim 1, wherein the carriage is moved by a majority of the moving distance of the sub-scan in the deceleration section of the total section of the deceleration section of one scan and the acceleration section of the next scan. The recording control method described in the above. 3. A carriage mounted with a recording head and reciprocating in a main scanning direction, a main scanning motor for controlling the movement of the carriage, a sub-scanning motor for conveying recording paper, and the main scanning motor. And motor control means for controlling each of the sub-scanning motors according to the acceleration, constant velocity, and deceleration movement trajectories by servo feedback control, and trajectories for calculating the movement trajectories prior to one main scan and one sub-scan, respectively. Calculation means; and 1 by servo feedback control of the main scanning motor.
Deceleration point monitoring means for monitoring the arrival of a deceleration point in scanning, and starting the sub-scanning by the sub-scanning motor when detecting the arrival of the deceleration point, wherein the sub-scanning by the sub-scanning motor is one scan of the carriage. The printing apparatus is executed within a total section of a deceleration section of the following and an acceleration section of the next scan. 4. The carriage is moved by a majority of the sub-scanning travel distance in a deceleration section of a total section of a deceleration section of one scan and an acceleration section of a next scan. The recording device according to any one of the preceding claims.