JPS60131270A - Transfer type thermal recorder - Google Patents

Abstract

PURPOSE:To permit homogenization of recording density by memorizing a carrying speed of a recording paper at the time of recording by continuing the carrying of the recording paper at the almost same speed as the memory carrier speed at the earliest until the time when the rear end of the recording paper is separated from a recording medium. CONSTITUTION:A printing control pulse 41 per each completion of printing of one line is supplied to a motor driving circuit 45 through OR circuit 44 in a motor controller circuit 39 and a step motor is made to carry out subscanning as much as one line by a driving pulse 46. On the other hand, a programmable counter 47 is enabled by Q output of FF circuit 48 which is set by a data end signal 42 and is preset by the interval data 38 of a counter 32 and a carrier control pulse 49 is output by the interval concerning this last data printing and the driving circuit 45 outputs driving pulse 46 continuously and with the same time cycle at the time of completion of printing. Thus, the ink donner sheet is carried at the almost same speed as the carrying speed at the time of printing, nd the occurrence of furrows is prevented and a recording density can be homogenized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer type thermal recording device using a sheet-shaped thermal recording medium.

[Prior art]

Transfer-type thermal marking devices exist as non-impact type recording bags that can make clear records on plain paper.

FIG. 1 shows an example of this transfer type thermal recording apparatus. A thermal recording medium (hereinafter referred to as an ink donor sheet) 11 of this device is wound around a supply roll 12! The ink donor sheet 11 fed out from the supply roll 12 is wound around the guide roller 13, between the thermal head 14 and the back roller 15, between the drive roller 16 and the pinch roller 17, and around the guide roller 18 in order. It is adapted to be wound up on a take-up roll 19.

The drive roller 16 transfers the pulsating force of the step motor 20 to a toothed pulley 21, a toothed belt 22, and a toothed pulley 23.
It rotates intermittently in the direction of the arrow. The winding roll 19 receives the driving force of the step motor 20 through a pulley 24,
It is transmitted via belt 25 and pulley 26 and rotates in the direction of the arrow.

On the other hand, the recording paper 28 sent out from the paper feed tray 27 passes between the thermal head 14 and the back roller 15 while being overlapped with the ink donor sheet 11 . At this time, the thermal head 14 is driven according to the supplied image signal. The ink donor sheet 11 is selectively heated by driving the thermal head 14, and the ink in the heated portion is transferred onto the recording paper 28, thereby performing recording. The recording paper 28 after recording is peeled off from the ink donor sheet 11,
It is transported in the direction of the arrow toward an output tray (not shown).

By the way, in such a transfer type thermal recording device, the recording paper 2
The frequency of the drive pulse of the step motor 20 is increased from the time when the rear end of the recording paper 28 passes through the square head 14, thereby shortening the time required until the recording paper 28 is ejected.

However, there is a problem in that the change in conveyance speed caused by this affects the recording density of the recording paper 28.

FIG. 2 is for explaining an example of such a change in recording density. As shown in this figure, if the peeling speed of the recording paper is different, the recording density will be different. This is because the amount of thermally transferable ink applied to the ink donor sheet depends on the peeling speed. The cause of this is not precisely known, and as the peeling speed increases, the recording density not only decreases but also increases in some cases. Figure 2 is 1
This figure shows an example of an ink donor sheet in which a halftone dot pattern with a 1-dot interval is printed at a recording density of /8 mm. In this example, the stripping speed is e.g. 30 m5ec/raste'r to 45 m'
When changing to S'ec/raster, the recording density becomes 0.
．． It decreases by 1. Since such a rapid change in recording density occurs within a single recording surface, it is very noticeable and causes deterioration of the quality of the recording surface.

[Purpose of the invention]

In view of these circumstances, it is an object of the present invention to provide a transfer type thermal recording device in which the peeling speed between a thermal recording medium and a recording paper is always kept substantially constant.

[Structure of the invention]

In the present invention, there is provided a storage means for storing the transport speed of the recording paper during recording, and a transport speed that is approximately the same as the transport speed stored in the storage means until at least the trailing edge of the recording paper is separated from the thermal recording medium. The transfer type thermal recording apparatus is provided with a recording paper forwarding speed control means for continuing conveyance of the recording paper. As a result, the peeling speed between the thermal recording medium and the recording paper is always approximately constant, and uniform recording density is achieved. Here, as the transport speed of the recording paper during recording, the repetition speed for heating drive of each unit heating element constituting the thermal head can be used.

〔Example〕

The present invention will be described in detail below with reference to Examples.

FIG. 4 shows the main parts of the transfer type thermal recording apparatus of this embodiment. A buffer memory 31 and an interval counter 32 of this device are supplied with video data 33 from a data transmission source (not shown).

Video data 33 is 1
The basic unit is image data for a line, and these data are repeatedly supplied. The buffer memory 31 is normally composed of line buffers for two lines, and image data is stored alternately one line at a time in these line buffers. These image data 34 are read line by line under the control of a thermal head controller 35 and supplied to a thermal head 36.

On the other hand, the interval counter 32 counts the time interval at which the synchronization signal arrives using a clock signal (not shown), and calculates the interval of each line.

The interval data 38 thus obtained is sent to the motor controller 39. Motor controller 3
Reference numeral 9 controls the step motor 20 based on the print control pulse 41 sent from the thermal head controller 35. Print control pulse 411t thermal head 3
6 is output at the timing when printing for one line is completed. Therefore, the period coincides with the period in which the thermal head is heated and driven line by line, and is not necessarily constant when performing divided driving or the like. The motor controller 39 causes the step motor 20 to sub-scan by one line when the print control pulse 41 is supplied.

At the stage when the printing operation on the recording paper 28 is completed, a data end signal 42 indicating the end of the video data 33 is sent from the above-mentioned transmission source. Data end signal 42 is supplied to motor controller 39. In the conventional transfer type thermal recording apparatus, the step motor 2O is driven at high speed after this point, and the recording paper 28 is quickly ejected. The motor controller 39 of this embodiment controls the drive of the step motor 2O based on the interval data 38 only for a predetermined time thereafter.

FIG. 4 specifically shows the motor controller. A print control pulse 41 output every time printing of one line is completed is an OR circuit 44 in the motor controller 39.
The signal is supplied to the motor drive circuit 45 via. Each time the motor drive circuit 45 generates a drive pulse 46, the step motor 20 (FIG. 3) sub-scans by one line.

The programmable counter 47 inputs the interval data 38 of the interval counter 32 to its preset input terminal. Data end signal 42
When the flip-flop circuit 48 is set by
As a result, the Q output 49 becomes H (high) level, and the programmable counter 47 is enabled. The programmable counter 47 is preset with the interval data 38 entered manually at this point, and outputs the withdrawal control pulse 49 at the interval regarding this last print data. The conveyance control pulse 49 is supplied to a motor drive circuit 45 via an OR circuit 44. As a result, the motor drive circuit 45
outputs drive pulses 46 continuously and at the same cycle as when printing ends.

When the recording paper 28 shown in FIG. 1 is completely peeled off from the ink donor sheet 11 and discharged to the discharge tray in this manner, a timing control circuit (not shown) outputs a discharge completion signal 5.
Outputs 1. The ejection completion signal 51 resets the flip-flop circuit 48 and also clears the contents of the program counter 47.

In this way, the withdrawal control of the recording paper 28 is completed.

In the embodiment described above, the conveyance speed of the recording paper 28 was kept almost constant until it was ejected to the output tray, but even if the conveyance speed of the recording paper was increased after it was completely peeled off from the ink donor sheet 11 good. When the peeling is completed, the drive pulses 46 supplied to the step motor 20 are counted,
This can be determined by a method such as detecting the recording paper 28 with an optical sensor.

〔Effect of the invention〕

As explained above, according to the present invention, the ink donor sheet is transported at almost the same speed as the transport speed during printing.
Unreasonable force is not applied to the sheet, and deformation of the ink donor sheet such as wrinkles can be prevented.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a transfer type thermal recording device, Fig. 2 is a characteristic diagram showing an example of the relationship between peeling speed and recording density, and Fig. 3 is a characteristic diagram showing an example of the relationship between peeling speed and recording density.
The figure is a block diagram showing the main parts of a transfer type thermal recording apparatus according to an embodiment of the present invention, and FIG. 4 is a block diagram embodying the motor controller of this apparatus. 11... Ink donor sheet, 28...
・Recording paper, 32...Interval counter, 39...
...Motor controller. Applicant' Fuji Xerox Co., Ltd. Agent Patent Attorney Umeo Yamauchi0

Claims (1)

[Claims] 1. A thermal pulse is applied line by line to a thermal recording medium coated with thermal transferable ink, and the ink is selectively transferred to a recording paper superimposed on the thermal recording medium. In a recording apparatus that performs thermal transfer recording using a line-sequential recording method, there is provided a storage means for storing the conveyance speed of the recording paper during recording, and a storage means for storing the conveyance speed of the recording paper at least until the trailing edge of the recording paper is separated from the thermal recording medium. 1. A transfer type thermal recording apparatus, comprising: a recording paper conveyance speed control means for continuing conveyance of the recording paper at substantially the same conveyance speed as the conveyance speed of the recording paper. 2. The transfer type thermal recording device according to claim 1, wherein the conveyance speed of the recording paper during recording is a repetition speed for heating drive of each unit heating element constituting the thermal head. .゛