JPH0630598A - Recorder - Google Patents

Abstract

PURPOSE:To provide a recorder that enables superior printing quality to be obtained without bringing about a cost increase or a drop in development efficiency. CONSTITUTION:In the period from the completion of previous printing P1 until the initiation of subsequent printing P2, a stepping motor is reversely rotated only (n) steps (n: natural number) that are below (m) steps (m: natural number) corresponding to a backlash of a driving force transmission mechanism which couples together a stepping motor and a platen roller. Subsequently, the stepping motor is normally rotated only (n) steps in such a way that this rotation continues to the normal rotation of the motor at subsequent printing P2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus using a stepping motor, for example, a recording apparatus applied to a heat-sensitive facsimile apparatus using a stepping motor.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus applied to, for example, a thermal type facsimile apparatus, a platen roller is driven by using a stepping motor. The most basic characteristic of the stepping motor is the frequency-torque characteristic shown in FIG.

In FIG. 8, a self-starting area (Start
Stop Region) is an area in which the step motor can be started, stopped, and rotated forward and backward in synchronization with the input pulse. The pull-in torque (pull-in torque) is the maximum torque that the step motor can start and stop in synchronization with the input pulse.

Through region
Is the high speed region of the step motor. In this area, unlike the self-starting area, the motor cannot be instantly started, stopped, or forward / reverse rotated. Pullout torque (escape torque)
Is the maximum torque that the step motor can generate without losing synchronization beyond the self-starting region. If the load is higher than this, the motor cannot rotate normally.

Here, in the through region, for example, when the steady drive frequency and the load torque are P ₀ and T ₀ , respectively, if the drive pulse P ₀ is suddenly input to the stepping motor from the motor stopped state, a step out (load torque) occurs. If the pulse frequency is too high or the pulse frequency is too high, a drive system called slew-up is used because it causes a discrepancy between the number of pulses and the movement of the motor. As shown in FIG. 9, the slew-up is a driving method in which a slew-up time t ₀ is applied to accelerate from a drive pulse P _s that clears the load torque T ₀ with a pull-in torque to a steady drive frequency P ₀ . By using the through-up method, the motor can be driven without causing step out.

[0006]

However, in the conventional recording apparatus, since the drive pulse is input to the stepping motor even during the slew-up, the stepping motor rotates and the recording paper moves accordingly. .
During this slew-up, since the rotation speed of the motor is slower than a predetermined steady speed, the transport speed of the recording paper is also slow. For this reason, as shown in FIG. 10, the rising of the movement of the recording paper (portion A in FIG. 10) is dulled. Ie 1
The time required for the recording paper to move by the line width l ₀ is longer than the other lines by the amount corresponding to the first line (1) at the beginning. The six arrows on the horizontal axis in FIG. 10 indicate the print timing. However, since the time required for color development of the recording paper is always the same, when printing is performed at such timing, the first line (1 color width l ₀₀ next), the resulting image, white spots as shown in FIG. 11 (a width l ₀ -l ₀₀₎ becomes an image. Further, as shown in FIG. 10, since the time interval between the first line (1) and the second line (2) increases, there is a possibility that the thermal head cools and a defective coloring occurs in the second line. As a measure for preventing such a problem, there is a method of changing the print timing, but it is not a sufficient measure because the movement of the recording paper itself is not evenly spaced. Moreover, since the system becomes very complicated by changing the printing timing, there is a problem that the cost is increased and the development efficiency is lowered.

Therefore, it is an object of the present invention to provide a recording apparatus which can obtain good print quality without causing an increase in cost and a decrease in development efficiency.

[0008]

The invention according to claim 1 is
To solve the above problems, a stepping motor, a control unit that drives the stepping motor, a recording paper conveyance roller that conveys recording paper, a stepping motor and a recording paper conveyance roller are connected, and the driving force of the stepping motor is recorded. A driving force transmission mechanism portion for transmitting to the paper transport roller,
In a recording apparatus that performs intermittent printing, the control unit controls n (natural number) equal to or less than the number of steps m (natural number) corresponding to backlash of the driving force transmission mechanism unit from the end of printing to the start of the next printing. ) The stepping motor is reversely rotated by the number of steps, and then the stepping motor is normally rotated by n steps so as to be continuous with the normal rotation operation of the stepping motor at the time of the next printing.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of the first aspect, when a step-up is required to prevent stepping out of the stepping motor,
It is characterized in that the control unit executes the slew-up at the time of the reverse rotation and the forward rotation for n steps.

[0010]

According to the first aspect of the invention, between the end of printing and the start of the next printing, n which is equal to or smaller than the number of steps m (natural number) corresponding to the backlash of the driving force transmission mechanism is n.
The stepping motor is reversely rotated by (natural number) steps, and then the stepping motor is normally rotated by n steps so as to continue the normal rotation operation of the stepping motor at the time of the next printing. Therefore, it is possible to prevent the rising of the movement of the recording paper from being deteriorated, and to prevent the occurrence of blank areas.

According to the second aspect of the invention, in addition to the operation of the first aspect, when the slew-up is required, the slew-up is executed at the time of the reverse rotation and the normal rotation for n steps. Therefore, step-out is prevented even in the through-up area.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 7 are views showing an embodiment of a recording apparatus according to the present invention, which is an example applied to a facsimile apparatus. First, the configuration will be described.

In FIG. 1, the facsimile apparatus 1 includes a scanner 2, a buffer memory 3, a data compression / reproduction unit 4, a transmission control unit 5, a modem 6, a network control unit 7, a system control unit 8, a mechanism control unit 9 and a plotter 10. And an operation unit 11 and the like. At the time of reception of this device, the modulated signal (image data) input from the line L is guided to the modem 6 via the network control unit 7, demodulated by the modem 6 and then compressed via the transmission control unit 5. The data is sent to the reproduction unit 4, reproduced by the data compression / reproduction unit 4 into the original information, and stored in the buffer memory 3. The image data stored in the buffer memory 3 is sent to the plotter 10 and printed and recorded on the recording paper 13. The mechanism control unit 9 controls the drive of the plotter 10 and the drive of the scanner 2 according to the instruction of the system control unit 8.

The system control unit 8 includes a facsimile machine 1
ROM (Read Only Memory) for storing the basic program of the above and the motor control program of the present invention, and RAM (Random Ac) in which a work area is formed.
process memory) and executes the sequence as the facsimile apparatus 1 according to the program in the ROM, and also executes the motor control process of the present invention.

As shown in FIG. 2, the plotter 10 is provided with a stepping motor 16, a driving force transmission mechanism 18, a recording paper conveying roller 19, and the like. Recording paper transport roller 1
Reference numeral 9 denotes a roller that conveys the recording paper 13, for example, a platen roller. The driving force transmission mechanism unit 18 connects the stepping motor 16 and the recording paper conveyance roller 19 to apply the driving force of the stepping motor 16 to the recording paper conveyance roller 19. Communicate to. As shown in FIG. 3, the driving force transmission mechanism 23 includes a motor gear 18a, a first intermediate gear 18b, and a second intermediate gear 18
c and a platen gear 18d. As is well known, the gear coupling of the driving force transmission mechanism portion 18 has backlash (meshing backlash). This driving force transmission mechanism 1
When the backlash of 8 is corrected to the number of steps of the stepping motor 16, it becomes m (natural number) steps.
Generally, backlash is the rotation of the platen roller, that is, when the motor is rotating in only one direction,
Does not affect the movement of the chart paper. When the rotation direction changes, the platen roller does not rotate even if the motor rotates by m steps at that time.

The mechanism control section 9 has a drive circuit 17, and the drive circuit 17 controls the drive of the stepping motor 16 according to an instruction from the system control section 8.
That is, the mechanism control unit 9 functions as a control unit of the present invention that controls the drive of the stepping motor 16, and causes backlash of the driving force transmission mechanism unit 18 between the end of printing and the start of the next printing. The stepping motor 16 is operated by n (natural number) steps equal to or less than the corresponding step number m.
Is reversed, and then the stepping motor 16 is rotated forward by n steps so as to be continuous with the normal rotation operation of the stepping motor 16 at the time of the next printing.

The timing of normal rotation, stop and reverse rotation of the stepping motor 16 of this embodiment and the timing of printing are shown in FIG. After the previous print P ₁ is completed, the stepping motor 16 is rotated in the reverse direction for n steps so that the stepping motor 16 is continuously rotated forward for the next print P ₂ before the start of the next print P ₂ . Rotate forward by a step.
However, there is a relationship of n ≦ m as described above. Therefore, only the stepping motor 16 rotates, the recording paper conveying roller 19 does not rotate, and the recording paper 13 does not move until the previous printing P ₁ ends and the next printing P ₂ starts. In addition, the reverse operation for n steps after the end of the previous printing P ₁ is
It may be carried out at any time during the section a shown in FIG.

Here, as shown in FIG. 5, the mechanical torque T ₁ during the backlash is smaller than the motor pull-in torque at the steady drive frequency P ₀ , that is, in the self-starting region, the slew-up is performed. No need, recording paper 1
In the movement of No. 3, as shown in FIG. 6, the rising edge of the movement of the recording paper (B portion in FIG. 6) is not sagging. Therefore, the time required for the recording paper 13 to move by one line width l ₀ is almost the same as the other lines even in the first first line (1), and the coloring width of the first line (1) is also other. the same l ₀ color width of the line and. Therefore, it is possible to prevent the blank areas shown in FIG. 11 that have occurred conventionally. In addition, since the time interval between the first line (1) and the second line (2) is prevented from increasing, it is possible to prevent the coloring failure of the second line (2) caused by the cooling of the thermal head. .

As described above, in the present embodiment, the above-mentioned effect can be achieved without changing the printing timing and the like, so that good printing quality can be obtained without causing an increase in cost and a decrease in development efficiency. It is possible to provide a recording device that can do this. On the other hand, as shown in FIG. 7, when the mechanical torque T ₂ during backlash is larger than the pull-in torque at the steady drive frequency P ₀ , that is, in the through area, the normal rotation of n steps before printing, It is sufficient to perform slew-up during reverse operation. Even in this case, the recording paper 13
Since the stepping motor 16 is rotating at the steady frequency before the movement of the recording paper 13 starts to move, the movement of the recording paper 13 becomes as shown in FIG.

[0020]

As described above, according to the present invention, it is possible to prevent a blank image by preventing the amount of movement of the recording paper at the start of movement of the recording paper without changing the printing timing. It is possible to maintain good print quality without lowering the print quality.

[Brief description of drawings]

FIG. 1 is a block diagram of a facsimile apparatus to which an embodiment of a recording apparatus according to the present invention is applied.

FIG. 2 is a block diagram showing details of a plotter portion of the apparatus shown in FIG.

FIG. 3 is a diagram illustrating a structure of a driving force transmission mechanism portion shown in FIG.

FIG. 4 is a diagram for explaining operation timings and print timings of a stepping motor in the apparatus shown in FIG.

5 is a torque-frequency characteristic graph of the stepping motor showing a case where the torque T ₀ during backlash is in the self-starting region in the apparatus of FIG.

FIG. 6 is a graph showing a change in recording paper movement amount in the apparatus of FIG.

7 is a torque-frequency characteristic graph of the stepping motor showing a case where the torque T ₂ during backlash is in the through region in the device of FIG. 1.

FIG. 8 is a torque-frequency characteristic graph of a stepping motor used in the description of the prior art.

FIG. 9 is a graph illustrating through-up of a conventional stepping motor.

FIG. 10 is a graph showing a change in the movement amount of a conventional recording paper.

FIG. 11 is a diagram illustrating the occurrence of a blank image in a conventional recording apparatus.

[Explanation of symbols]

 9 Mechanism Control Section (Control Section) 16 Stepping Motor 18 Driving Force Transmission Mechanism Section 19 Recording Paper Conveying Roller

Claims (2)

[Claims] 1. A stepping motor, a control section for driving the stepping motor, a recording sheet conveying roller for conveying a recording sheet, a stepping motor and a recording sheet conveying roller are connected, and the driving force of the stepping motor is conveyed to the recording sheet. In a recording device for performing intermittent printing, which comprises a driving force transmission mechanism unit for transmitting to a roller, the control unit controls the backlash of the driving force transmission mechanism unit between the end of printing and the start of the next printing. The stepping motor is rotated in the reverse direction by n (natural number) steps equal to or less than the number of steps m (natural number) corresponding to, and then the stepping motor is moved n steps so as to be continuous with the normal rotation operation of the stepping motor at the time of the next printing. A recording device characterized by rotating forward by a minute. 2. A control unit executes slew-up during reverse rotation and forward rotation for n steps, when slew-up is required to prevent stepping out of the stepping motor. The recording apparatus according to 1.