JP2783549B2 - Recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus that stores encoded image information in a memory, and sequentially decodes and records the image information.

[Prior Art] Conventionally, as a device of this type, for example, in a facsimile device, the same data is printed a plurality of times in order to compensate for insufficient white stripe density of a recorded image.

However, in the related art, the same data is simply printed a plurality of times at the same position.

[Problems to be Solved by the Invention] Therefore, in the above-described conventional example, since the auxiliary printing is performed irrespective of the remaining amount of the image memory, a slight density unevenness occurs due to a change in the recording cycle. In addition, since the recording paper was not moved, after printing several lines continuously in one page, if there was suddenly no data and the operation stopped, the recording paper was moved (for example, due to block transmission or the capacity of the transmission side memory). Did not reach the predetermined position, there were cases where white stripes occurred in the image. When the stop time is long, even if the recording position is a predetermined position, printing is performed a plurality of times in the same place, so that the thermal head and the recording paper are stuck to each other. There is a disadvantage that the image is disturbed. Further, there is also a drawback that since the printing is not performed for a long time, the heat generating portion of the head is cooled and the next line cannot be recorded with a sufficient density.

The present invention has been made in view of the above-described drawbacks, and has as its object to prevent the thermal head from sticking to the recording paper during auxiliary recording.

[Means for Solving the Problem] The present invention relates to a thermal head that records image data on recording paper in units of one line, and a determination unit that determines whether or not to suspend recording during continuous recording of a plurality of lines. A recording unit that conveys a recording sheet in units of one line in response to a drive signal in units of one line, and that delays the actual movement of the recording sheet from the time when the driving signal is input; In response to the completion of the recording, the thermal head performs the auxiliary recording for re-recording the last line recorded before the recording was interrupted, and the conveyance unit continues to convey the recording paper even while the auxiliary recording is being performed. Control means for causing

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the facsimile apparatus in the present embodiment. 1 is a CPU for controlling the operation of the facsimile machine (comprising a microcomputer and a ROM storing a control program, a RAM for storing data, etc.),
2 is a modem for demodulating signals from 3 NCUs and 4 lines,
5 is a FIFO (first-in-first-out) type memory for storing received image data, 6 is coded by a coding method such as a demoif-it-howman (MH) or demodulated-read (MR) method. A decoding unit for decoding the image data and converting it to serial data for transfer to the thermal head 8; a recording control unit 7 for driving a thermal head and a recording paper transport motor 9 (microcomputer and ROM, RAM, etc.) Peripheral devices).

FIG. 2 is a flowchart showing the control operation of the recording control unit 7 of the present embodiment.

In step S10, it is determined whether a print command has been received from the CUP. If yes, the recording paper is advanced by one step (predetermined amount) in step S20, and one line is printed in step S30. The required time for moving one step of the recording paper and the voltage application time for one-line printing are the same (for example, 2.5 ms). During this recording, if the memory 5 is empty (empty), a memory empty command is received from the CPU via 1-b during the printing of step S30. If not, the process returns to step S10. The recording control unit of the conventional machine repeats this loop to print one page.

If the memory empty command has been received, the motor phase in the direction to advance the recording paper by one step is excited in step S50. Next, in step S60, auxiliary printing is performed.
The data is divided and recorded with one scan at 2.5 ms. However, this is an auxiliary print in which the same data is printed in three scans with a shorter pulse width in 2.5 ms. FIG. 3 shows this timing diagram.

As soon as the data of the next line is ready, CUP1 sends the next print command.In this case, this printing is immediately terminated and the printing of the next line is started.However, the fact that the memory empty command is received in step S40 means that It is considered that the data of the line of the first line is late, and the possibility is low. If a print command for the next line has been received in step S70, the recording paper has already been sent one step in step S50, so the process jumps to step S30 and the auxiliary printing is stopped even in the middle of the scan or block to print the next line.

If the auxiliary printing is repeated a predetermined number of times while monitoring this print command in steps S60 to S80,
In step S90, the motor phase is returned by one step, and in step S10, the next print command is waited for.

With this control, the motor advances one step at step S50, but the movement of the recording paper does not actually follow this time,
Also, since the pulse of the auxiliary printing is short, the printing of the main line does not overlap the recording position of the next line.

FIG. 4 shows the relationship between the time t and the moving distance s of the recording paper even when printing is stopped after continuous printing under the conventional control, and FIG. 5 shows ts when the present invention is implemented. In both figures,
The broken line indicates an ideal movement, and the solid line indicates the actual movement.

The area shown in FIG. 4 is in a state of continuous recording, and printing is performed continuously, so that the inclination of the recording paper movement is constant, but there is a delay with respect to the excitation of the motor, and the recording is stopped in the area II. In this case, if the auxiliary printing is not performed, the S1 portion is not recorded and white stripes are formed. In addition, if auxiliary printing is performed in this state, auxiliary scanning is performed in a portion where the recording paper does not move much, and the stopping time of the area II is long, so that the stinging is intense, as shown by the solid line in the area III when recording is restarted. Move. In this case, the movement distance of the print strobe 6 in the time is large, and white streaks occur in the image in this portion. If the auxiliary printing is not performed, the staging becomes small, but the line of the print strobe 4 has a long recording interval, so that the heating resistor does not reach a sufficient temperature and the density is reduced.

FIG. 5 is a recording timing chart according to the present embodiment.
A part where paper is advanced without recording by completing auxiliary printing while moving the motor in the forward direction after printing the third line (S1)
And compensate for the lack of concentration after a long stop. Also, during the auxiliary printing, advance the recording paper and return it after the end, so that it is not affected by staging, and the next time printing starts, the recording movement delay is minimized like the III area be able to. The stateing is caused by heat applied in a state where the paper and the heating resistor are in contact with each other and cooled as it is. However, in the area II in FIG. No stateing occurs because the recording paper is moved.

[Other Embodiments] In the above embodiment, the one-step motor is advanced in step S50. However, if the facsimile apparatus has good tracking of the recording paper to the motor phase, the phase to be advanced by one step is excited. Lower the current, slow down the speed of movement,
It is also conceivable to step back.

In this embodiment, the main control unit monitors the amount of data in the memory and sends a command to the recording control unit.This is because the recording control unit has means for detecting the remaining memory capacity, or the main control unit performs recording. The same holds true for controlling the operation.

[Effects of the Invention] According to the present invention, a thermal head that records image data on recording paper in units of one line, and the recording paper is transported in units of one line in response to a drive signal in units of one line, In a recording apparatus having a conveyance unit that causes a delay in the actual movement of the recording paper from the time of input, it is determined whether or not to suspend recording during continuous recording of a plurality of lines. Accordingly, the thermal head performs auxiliary recording to record the last line recorded before the recording was interrupted again, and continues to transport the recording paper while performing the auxiliary recording. Even after the recording operation is stopped, the recording paper is transported due to the delay of the transport of the recording paper by the transporting means, and the recording paper is transported without performing the recording operation on the thermal head. Auxiliary recording can be used to prevent the thermal head and the recording paper from sticking to each other when the amount of movement between the thermal head and the recording paper is small when the last line recorded before the interruption of the recording is small. This allows
It is possible to prevent the actual start of movement of the recording paper from being delayed from the application of the drive signal at the start of recording to be further delayed than a normal delay, thereby preventing the recorded image from becoming uneven.

According to a second aspect of the present invention, the thermal head has a memory unit for storing image data, the thermal head records the image data read from the memory unit, and the determination unit Since it is determined that the recording is interrupted in accordance with the absence of the image data to be recorded in the memory means, if this recording device is used for a communication device such as a facsimile device, the received image data is stored in the memory, While the image data stored in the memory is being recorded on the recording paper, the reception is not in time, and even if the memory becomes empty, white stripes and unevenness do not occur in the recorded image.

According to the third aspect of the present invention, after the recording paper is continuously transported during the auxiliary recording, the recording paper is continuously transported during the auxiliary recording. The recording paper is transported in the reverse direction by the transport distance, and after the transport in the reverse direction, the recording of the image data is restarted. The recording paper is transported to the paper, the time to continue transporting the recording paper can be extended, the thermal head and the recording paper can be reliably prevented from sticking, the recording paper is returned in the opposite direction, and the image at the joint when recording is resumed Disturbance can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the facsimile apparatus of this embodiment, FIG. 2 is a flowchart of the recording control unit, FIG. 3 is a timing chart of print pulses of each block of the thermal head, and FIG. FIG. 5 is a recording timing chart according to the conventional recording method, and FIG. 5 is a recording timing chart according to the present embodiment. 1 is a CPU, 2 is a demodulation unit, 3 is an NCU, 4 is a line, 5 is an image memory, 6 is a decoding unit, 7 is a recording control unit, 8 is a thermal head, and 9 is a recording step motor.

Claims (3)

(57) [Claims] 1. A thermal head for recording image data on recording paper in units of one line, and a recording paper is conveyed in units of one line in accordance with a drive signal in units of one line, and actual recording is performed from the time of input of the drive signal. Conveying means causing a delay in the movement of the paper, determining means for determining whether or not to stop the printing during continuous printing of a plurality of lines, and printing in response to the determining means determining that the printing is to be interrupted. Control means for causing the thermal head to perform auxiliary recording for re-recording the last line recorded before the interruption, and for causing the transport means to continue transporting the recording paper even while performing the auxiliary recording. Recording device. And a memory means for storing image data.
The thermal head records the image data read from the memory unit, and the determining unit determines that the recording is interrupted in response to the absence of image data to be recorded in the memory unit. The image recording apparatus according to claim 1. 3. The method according to claim 1, wherein the control unit causes the transport unit to continue transporting the recording paper even during the auxiliary recording.
The recording paper is transported in the reverse direction by the transport distance continuously transported during the auxiliary recording, and recording of the image data is resumed after the transport in the reverse direction. 2. The image recording apparatus according to claim 1, wherein: