JPH04320858A - Thermal recording method and its device - Google Patents

Abstract

PURPOSE:To provide a thermal recording method which can obtain a recording image which is little in irregularity of density, white streaks, etc., and its device by a method wherein time from start of carrying a recording medium to start of recording operation is varied according to the number of times wherein recording is repetitively performed by a line unit. CONSTITUTION:Waiting time is determined according to the number of times wherein recording repetitively performed. After starting drive of a carrying motor 7 which carries a recording medium, said waiting time has elapsed and thereafter, operation is performed so that recording operation with a recording head 8 is started.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording method and apparatus, and more particularly to a thermal recording method and apparatus for recording by changing the linear density in the sub-scanning direction.

0002

2. Description of the Related Art During thermal recording using a thermal head equipped with heating elements for one line, moving writing is often adopted in which recording is performed while the recording paper is being conveyed in the sub-scanning direction in order to shorten the recording time. There is. In this case, the recording paper is conveyed by transmitting the rotation of a stepping motor for conveying the recording paper to a platen roller via a gear, and the recording paper is conveyed in the sub-scanning direction by the rotation of the platen roller. The reason why the recording paper actually starts to move due to the rotation of this conveyance motor is due to frictional load and loss in the gear section, so the rotational drive of the recording paper conveyance motor is started (excitation of the next phase). This is several ms after. Therefore, in order to keep the quality of the recorded image constant, a waiting time is required from the start of transport of the recording paper to the actual start of recording. While measuring this waiting time,
In some cases, preheating is performed using previous line data or all black data, but conventionally, this waiting time has always been set constant regardless of the sub-scanning line density.

0003

[Problem to be Solved by the Invention] Current facsimile machines compatible with super fine mode employ a thermal head equipped with one line of heating elements with a length of 1/15.4 (mm) in the sub-scanning direction. There is. In such a facsimile machine, the same data is recorded four times (line) in a row in the standard mode of 3.85 lines/mm, and the same data is recorded two times (line) in a row in the fine mode of 7.7 lines/mm. In the super fine mode of 15.4 lines/mm, the data is recorded once (line), and the recording paper is 1/15.4 (mm) for each line recorded.
) while recording at a sub-scanning line density corresponding to each mode.

Furthermore, the recording cycle of each line during facsimile reception recording varies depending on the complexity of the recorded data, and each line is recorded intermittently. Further, after the recording paper conveyance motor is energized, it takes time until the recording paper actually starts moving. For this reason, in the case of moving writing mentioned above, if you do not record while the recording paper is constantly moving, uneven density and white lines between lines will occur, so do not record until the recording paper starts to move. However, if this waiting time is kept constant, if the sub-scanning line density is low, especially in the standard mode, as mentioned above, the same recording data will be recorded for 4 consecutive lines, and at this time, the recording paper will be Since the transport motor is driven, the movement of the recording paper ends when the fourth line is recorded, resulting in stationary writing, causing density unevenness.

The present invention has been made in view of the above-mentioned conventional example, and is capable of reducing density unevenness by changing the time from the start of conveyance of the recording medium to the start of the recording operation according to the number of times of repeated recording in units of lines. It is an object of the present invention to provide a thermal recording method and apparatus that can obtain recorded images with fewer white lines and white lines.

[0006]

Means for Solving the Problems In order to achieve the above object, the thermal recording apparatus of the present invention has the following configuration. That is, the thermal recording apparatus records on a recording medium using a recording head that performs recording line by line, and includes a conveying means for conveying the recording medium, and after the driving of the conveying means is started, a recording operation by the recording head is started. Depending on the timer that measures the waiting time and the number of times it is repeatedly recorded,
and control means for controlling the waiting time measured by the time measuring means to be changed and recorded.

[0007] In order to achieve the above object, the thermal recording method of the present invention includes the following steps. In other words, it is a thermal recording method in which recording is performed on a recording medium using a recording head that performs recording line by line, and includes a step of determining a waiting time according to the number of times of repeated recording, and a step of starting driving of a conveyance motor that conveys the recording medium. and a step of starting a recording operation by the recording head after the waiting time has elapsed.

[0008]

[Operation] In the above configuration, recording is performed by measuring the waiting time from the start of conveyance of the recording medium until the start of recording operation by the recording head, and the counted waiting time is determined according to the number of times of repeated recording. Changed and recorded.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. <Description of Facsimile Apparatus (FIG. 1)> FIG. 1 is a block diagram showing a schematic configuration of the facsimile apparatus of this embodiment.

In FIG. 1, 1 is a main control section that controls the entire apparatus, and 2 is an operation/display section that includes an operation panel, a liquid crystal display, and the like. Reference numeral 3 denotes a reading section which photoelectrically reads the original image and inputs image data. 4 is a communication control unit,
It is connected to a communication line via a network control unit (NCU) 5 and performs various controls for facsimile communication. 6 is
For example, it is equipped with a 1-chip microcomputer having a ROM 61 that stores a control program for the CPU 60 and various data described later, a RAM 62 that is used as a work area for the CPU 60, and a timer 63 that measures time according to instructions from the CPU 60. The recording control unit controls power supply to a recording paper transport motor 7 that transports recording paper, which is a recording medium, and a thermal head 8, which is a recording device. A thermistor 9 is a temperature sensor that detects the temperature of the thermal head 8 and outputs temperature information.

With this configuration, during a copying operation, the thermal head 8 is driven to generate heat based on image data read by the reading section 3 to record. In the case of facsimile image reception, image data received from a communication line via the NCU 5 and demodulated by the communication control section 4 is converted by the main control section 1 into a form recordable by the thermal head 8. The main controller 1 controls the recording controller 6 each time one line of the converted image data is transferred to the thermal head 8.
Send a print command to. Upon receiving this, the recording control section 6 starts moving the recording paper and simultaneously drives the thermal head 8 to generate heat according to the temperature of the thermal head 8, thereby recording one line.

When recording one line, in order to reduce the number of heating elements that are energized at the same time and to downsize the power supply of the device, the heating elements for one line of the thermal head 8 are usually arranged in multiple blocks of about 2 to 8 blocks. One line of data is recorded by dividing each block into blocks and sequentially energizing each block. The energization time (application time) to each block at this time is called the energization pulse width.

In such recording line by line,
Line conditions, modem (modem/demodulator) capabilities, complexity of received facsimile image data (number of black and white dot inversions)
The time it takes for one line of data to become complete and recordable varies depending on the encoding format, sub-scanning line density, etc., resulting in intermittent recording with a random recording cycle.

When the sub-scanning line density is low, that is, when the super fine mode is not used, after one line of recording data is transferred from the main control unit 1 to the thermal head 8, the sub-scanning line density is sent to the print command. At the same time, it is output to the recording control section 6. As a result, in the standard mode, the recording control unit 6 prints 1/15.4 of the recording paper for each line.
(mm) while recording the same recording data for 4 lines, and in fine mode, the same recording data is recorded for 2 lines while conveying the recording paper by 1/15.4 (mm) for each line. Minutes are recorded. The timer 63 measures the waiting time between the recording paper conveyance operation and the recording operation.

FIG. 2 is a diagram showing an example of recording in super fine mode (sub-scanning line density 15.4 lines/mm) and the timing of conveying the recording paper. Here, the vertical axis is the moving distance of the recording paper, the horizontal axis is the time, and the moving state of the recording paper is shown by a curve.

MT1 is a signal indicating the drive start timing of the recording paper transport motor 7 (the next phase excitation start timing of the motor), and after this MT1, energization for recording is started after waiting a waiting time t0. ing. Further, in FIG. 2, preheating (PH) is performed to warm the thermal head 8 to such an extent that the thermal head 8 does not perform recording during the waiting time t0.

FIG. 3 is a timing diagram showing the recording timing in the standard mode in the facsimile apparatus of this embodiment.

MT2 to MT5 indicate drive start timings of the recording paper transport motor 7, similar to the above-mentioned MT1;
To record one line of data in super fine mode, the recording paper conveyance motor is driven four times to convey the recording paper, and the same data is recorded four times (in the conventional example, P10 to P1
3. In this embodiment, P20 to P23) are recorded.

At this time, the waiting time from starting the rotation of the recording paper transport motor 7 to actually energizing the thermal head 8 to perform recording is the same as in the super fine mode shown in FIG. t0), then at the fourth recording (P1
In 3), the movement of the recording paper stops, or overshoots or undershoots occur. As a result, the recording density becomes excessively high, and sticking occurs. Therefore, in this embodiment, recording is performed with this waiting time shortened.

[0020] Below, with reference to the flowchart of FIG.
This example will be explained in detail.

FIG. 4 is a flowchart showing the recording operation executed by the CPU 60 of the recording control section 6 of the facsimile machine of this embodiment.
It is stored in M61.

In step S1, when a print command is input from the main control section 1, the process proceeds to step S2, and rotational driving of the recording paper transport motor 7 is started. At this time, one line of recording data is transferred to the thermal head 8, and then a latch signal is output, so that the recording data for driving the heating resistor of the thermal head 8 is latched into the thermal head 8. Ru. Next, the process proceeds to step S3, where the sub-scanning line density is determined based on the current reception mode. If it is super fine mode, proceed to steps S4 and S5;
The timer 6 measures the waiting time t0 (see FIG. 2) from the start of driving of the recording paper transport motor 7 to the start of the recording operation.
3, and the value of the counter n is set to "0".

On the other hand, if it is the fine mode, step S
6. Proceed to S7, set the waiting time to t1, and set the counter n to "1". If it is the standard mode, the process proceeds to steps S8 and S9, where the waiting time is set to t2 and the counter n is set to "3". Here, t0>t1>t2
, t0 is approximately 2 ms, and t2 is approximately 1 ms. Further, the counter n is used to count the number of lines for recording 1 line in the super fine mode, 2 lines in the fine mode, and 4 lines in the standard mode.

When the waiting time and the value of the counter n are determined in this way, the process proceeds to step S10, where the waiting time value is set in the timer 63 and the timing of the waiting time is started. Step S
When it is confirmed that the timer 63 has finished counting time in step S11 and that the waiting time has elapsed, the process proceeds to step S12, where the thermal head 8 is energized and the recording operation is started.

During this recording operation, the thermal head 8 is divided into a plurality of blocks and driven to generate heat. When recording data for the next line is prepared while each block is energized, it is sequentially transferred to the thermal head 8 and stored in a shift register (not shown) provided in the thermal head 8. However, as described above, in the standard mode, for example, the same data is recorded four times in a row, so this transferred line data remains stored in the shift register. The recording data stored in this shift register is then set in a latch circuit for actual recording in step S2.

In step S13, when all blocks of the thermal head 8 are energized and recording of one line is completed, the process proceeds to step S14, where it is determined whether n=0. If the value of n is not "0", the process advances to step S15, and the recording paper transport motor 7 is further driven to rotate, the value of n is subtracted by "1" in step S16, and the process returns to step S12 again, and the above-described recording is performed again. Repeat the action.

If n=0 in step S14, this means that recording for one line at each sub-scanning line density has been completed, so the process advances to step S17 to check whether recording for one page has been completed. If the recording for one page is not completed, the process returns to step S1 again and the recording operation is repeated from the next line.

In this embodiment, the recording control unit 6 controls the power supply to the thermal head 8, but the present invention is not limited to this, and the main control unit 1 alone may control the power supply. good.

In addition, in the case of thermal transfer recording, preheating of the thermal head during the above-mentioned waiting time causes
Since the thermal head and ink sheet are warmed, the advantage is that recording operations and ink sheet conveyance processing become smoother. Furthermore, in thermal transfer recording, the waiting time from the start of transport drive of the ink sheet until the start of the recording operation can be controlled in the same way.

The present invention may be applied to a system made up of a plurality of devices, or to a device made up of one device. It goes without saying that the present invention can also be applied to cases where the present invention is achieved by supplying a system or device with a program that executes the processing defined by the present invention.

As explained above, according to this embodiment, density unevenness, sticking, etc. can be prevented by changing the waiting time from the start of driving of the recording paper transport motor until the start of recording according to the sub-scanning line density. It is possible to obtain high-quality recorded images with fewer white lines and the like.

[0032]

As explained above, according to the present invention, by changing the time from the start of conveyance of the recording medium to the start of the recording operation according to the number of times of repeated recording in units of lines, for example, density unevenness can be reduced. This has the effect of making it possible to obtain recorded images with fewer white lines and lines.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a facsimile apparatus according to an embodiment.

FIG. 2 is a timing chart showing an example of recording timing in a super fine mode in the facsimile apparatus of this embodiment.

FIG. 3 is a timing diagram showing an example of recording timing in a standard mode in the facsimile apparatus of this embodiment.

FIG. 4 is a flowchart showing recording control processing in the facsimile apparatus of this embodiment.

[Explanation of symbols]

1 Main control section 2　Operation/display section 3 Reading control section 4 Communication control section 5 NCU 6 Recording control section 7 Recording paper conveyance motor 8 Thermal head 9 Thermistor

Claims (3)

[Claims] 1. A thermal recording device that records on a recording medium using a recording head that performs recording line by line, comprising: a conveying means for conveying the recording medium; and after starting driving of the conveying means, recording by the recording head. It has a timer for measuring the waiting time until the start of the operation, and a control means for controlling the waiting time measured by the timer to be changed and recorded according to the number of times of repeated recording. A thermal recording device featuring: 2. The thermal recording apparatus according to claim 1, wherein the control means determines the number of times of repeated recording according to the sub-scanning line density to be recorded. 3. A thermal recording method for recording on a recording medium using a recording head that performs recording line by line, the step of determining a waiting time according to the number of times of repeated recording;
A thermal recording method comprising the step of starting a recording operation by a recording head after the waiting time has elapsed after starting driving of a transport motor for transporting a recording medium.