JPH04320856A - Thermal transfer recording method and device, and facsimile machine using the device - Google Patents

Abstract

PURPOSE:To provide a thermal transfer recording method which makes separation of an ink sheet from a recording medium after recording an image easy, its device, and facsimile equipment using said device by a method wherein when a line of which the number of black dots of a recording data is not less than a specific number exists, energy to be applied to a recording line is controlled before recording said line or after recording said line. CONSTITUTION:The number of black dots of each line to be recorded by a line unit is counted with a black dot counter 134, and a line before a specific number of lines including the line of which the number of black dots are not less than a specific number and/or a specific number of lines following said line are operated so that energy applied to a thermal head 13 is decreased to perform printing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording method and apparatus for recording an image on a recording medium by transferring ink contained in an ink sheet to a recording medium, and a facsimile machine using the apparatus.

0002

[Prior Art] Generally, thermal transfer printers use an ink sheet with heat-melting (or heat-sublimable) ink applied to a base film, and a thermal head selectively heats the ink sheet in response to image signals. Images are recorded by transferring melted (or sublimated) ink onto recording paper. Generally, this ink sheet is one in which the ink is completely transferred to the recording paper by one image recording (a so-called one-time sheet), so after the image recording of one character or one line is completed, the recorded length is It was necessary to convey the ink sheet by the amount corresponding to the amount of the ink sheet, and to surely bring the unused portion of the ink sheet to the next recording position. For this reason, the amount of ink sheets used has increased, and the running cost of thermal transfer printers has tended to be higher than that of ordinary thermal printers that record on thermal paper.

[0003] In order to solve these problems, as shown in Japanese Patent Application Laid-open No. 57-83471, Japanese Patent Application Publication No. 58-201686, or Japanese Patent Publication No. 62-58917, recording paper and ink sheet have been developed. A thermal transfer printer has been proposed that conveys images at different speeds.

The present invention is a further development of the invention described in the above publication.

[0005]

[Problems to be Solved by the Invention] As ink sheets used in these thermal transfer printers, ink sheets capable of recording images a plurality of times (so-called multi-print sheets) are known. For example, when recording a recording length L continuously, the conveyance length of the ink sheet conveyed after each image recording or during image recording is made smaller than the length L (L/n: n>1). can be recorded. As a result, the usage efficiency of the ink sheet is n times higher than that of the conventional method, and it is expected that the running cost of the thermal transfer printer will be reduced. Hereinafter, this recording method will be referred to as multi-print.

In the case of multi-printing using such an ink sheet, the ink in the ink layer of the ink sheet is heated n times. Each time the ink is heated, a shearing force is generated between the melted ink and the unmelted ink in the ink layer, and the ink is transferred onto the recording paper. For this reason, for example, when the time between recording one line and recording the next line increases and the temperature of the ink decreases, the shearing force between the melted ink layer and the unmelted ink layer increases, causing the ink sheet to There was a problem that it became difficult to separate the paper and the recording paper. This problem occurs particularly when there is a lot of black information in one line of recorded data. This is because when the amount of melted ink is large, the adhesion force between the recording paper and the ink sheet increases when the melted ink solidifies as the ink cools. This increase in adhesion force causes the ink sheet to stretch and the rubber of the platen roller to bend. If multi-printing is performed by setting the relative speed between the ink sheet and the recording paper, this problem may occur. The relative speed approaches 0, making it impossible to perform proper multi-printing. This is particularly a problem in devices such as facsimile machines where the time interval between recording the current line and the next line is not constant and the time interval is relatively long.

The present invention has been made in view of the above-mentioned conventional example, and when there is a line in which the number of black dots of print data is more than a predetermined number, an electric current is applied to the print head before or after printing that line. It is an object of the present invention to provide a thermal transfer recording method and apparatus that facilitates separation of an ink sheet and a recording medium after image recording by controlling energy, and a facsimile apparatus using the apparatus.

[0008]

Means for Solving the Problems In order to achieve the above object, the thermal transfer recording apparatus of the present invention has the following configuration. That is, it is a thermal transfer recording device that transfers ink contained in an ink sheet to a recording medium to record an image on the recording medium, and includes an ink sheet conveying means that conveys the ink sheet, and a recording device that conveys the recording medium. a medium conveying means, a recording means for recording an image on the recording medium line by line by acting on the ink sheet, and a counting means for counting the number of black dots in a line recorded by the recording means;
control means for controlling the recording means to record with lower energy applied to the recording means than a line before the line by a predetermined number, including a line in which the number of black dots counted by the counting means is greater than or equal to a predetermined number; have

A facsimile apparatus according to another invention has the following configuration. That is, it is a facsimile machine using a thermal transfer recording device that transfers ink contained in an ink sheet to a recording medium to record an image on the recording medium, and includes an image input means for inputting an original image, and a facsimile signal transmission/reception unit. a transmitting/receiving means for inputting the image input means or the image signal from the transmitting/receiving means to create recording data; an ink sheet conveying means for conveying the ink sheet; and an ink sheet conveying means for conveying the recording medium. a recording medium conveying means; a recording means for recording an image on the recording medium line by line by acting on the ink sheet conveyed by the ink sheet conveying means based on the recording data; and 1 included in the recording data. A counting means for counting the number of black dots in a line, and lowering the energy applied to the recording means from a line before a predetermined number of lines, including a line in which the number of black dots counted by the counting means is greater than or equal to a predetermined number. and a control means for controlling the recording mode.

A thermal transfer recording method according to another invention has the following configuration. That is, it is a thermal transfer recording method in which ink contained in an ink sheet is transferred to a recording medium to record an image on the recording medium. , when the number of black dots is a predetermined number or more, the energy applied to the recording head is reduced when recording a predetermined number of lines preceding the line and/or a predetermined number of lines following the line. .

[0011]

[Operation] In the above configuration, the number of black dots of the line recorded by the recording means is counted, and the number of black dots is determined to be greater than or equal to a predetermined number based on the counted value.
It operates to record a predetermined number of lines before that line and/or a predetermined number of lines following that line by lowering the energy applied to the recording means.

0012

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 device (FIGS. 1 to 4)> FIGS. 1 to 4 are diagrams showing an example in which a thermal transfer printer using an embodiment of the present invention is applied to a facsimile device, and FIG. 1 shows the control of the facsimile device. 2 is a block diagram showing a schematic configuration of the facsimile device, FIG. 3 is a side sectional view of the facsimile device, and FIG. 4 is a conveyance mechanism for recording paper and ink sheets. FIG.

First, the schematic structure of the facsimile machine of the embodiment will be explained based on FIG.

In FIG. 2, reference numeral 100 denotes a reading unit that photoelectrically reads an original and outputs it as a digital image signal to a control unit 101, and is equipped with an original conveyance motor, a CCD image sensor, and the like. Next, the configuration of this control section 101 will be explained. 110 is a line memory for storing image data of each line of image data; when transmitting or copying an original, one line of image data from the reading unit 100 is stored; when receiving image data, it is decoded; One line of received image data is stored. and,
An image is recorded on recording paper by outputting the stored data to the recording unit 102. Reference numeral 111 denotes an encoding/decoding unit that encodes image information to be transmitted by MH encoding or the like, and decodes received encoded image data to convert it into image data. Further, 112 is a buffer memory that stores encoded image data that is transmitted or received. Each part of the control unit 101 is controlled by a CPU 113 such as a microprocessor. In addition to this CPU 113, the control unit 101 includes a C
It includes a ROM 114 that stores control programs and various data for the PU 113, and a RAM 115 that temporarily stores various data as a work area for the CPU 113.

Reference numeral 102 denotes a recording section which is equipped with a thermal line head and records an image on a recording paper by a thermal transfer recording method, and this configuration will be described in detail later with reference to FIG. Reference numeral 103 denotes an operation unit including various function instruction keys such as start of sending, telephone number input keys, etc. 103a is a switch for instructing the type of ink sheet to be used. When the switch 103a is on, a multi-print ink sheet is used. , when off, it indicates that a normal ink sheet is loaded. A display section 104 is usually provided adjacent to the operation section 103 and displays various functions, the status of the device, and the like. 105 is a power supply unit for supplying power to the entire device. Further, 106 is a modem (modulator/demodulator), 107 is a network control unit (NCU) that performs automatic call receiving operation and line control operation based on ring tone detection, and 108 is a telephone set.

Next, the configuration of the recording section 102 will be explained in detail with reference to FIG. Note that common parts in each drawing are indicated by the same figure number.

In the figure, 10 is a recording paper 1 which is plain paper.
1 is wound into a roll shape around a core 10a. The roll paper 10 is rotatably housed in the apparatus so that the recording paper 11 can be supplied to the thermal head section 13 by rotation of the platen roller 12 in the direction of the arrow. Note that 10b is a roll paper loading section, in which the roll paper 10 is removably loaded. Furthermore, a platen roller 12 conveys the recording paper 11 in the direction of arrow b and presses the ink sheet 14 and the recording paper 11 between it and the heating element 132 of the thermal head 13. Recording paper 1 on which image recording was performed due to heat generated by the thermal head 13
1 is conveyed toward the discharge rollers 16 (16a, 16b) by further rotation of the platen roller 12, and when image recording for one page is completed, the cutters 15 (15a, 15
b) It is cut into pages by the meshing of.

Reference numeral 17 indicates an ink sheet supply roll that winds the ink sheet 14, and 18 indicates an ink sheet winding roll, which is driven by an ink sheet conveyance motor to be described later and winds up the ink sheet 14 in the direction of arrow a. It is something. Note that the ink sheet supply roll 17 and the ink sheet take-up roll 18 are removably loaded into an ink sheet loading section 70 within the main body of the apparatus. Furthermore, 1
Reference numeral 9 denotes a sensor for detecting the remaining amount of the ink sheet 14 and the conveying speed of the ink sheet 14. Further, 20 is an ink sheet sensor for detecting the presence or absence of the ink sheet 14, and 21 is a spring that presses the thermal head 13 against the platen roller 12 via the recording paper 11 and the ink sheet 14. Further, 22 is a recording paper sensor for detecting the presence or absence of recording paper.

Next, the configuration of the reading section 100 will be explained.

In FIG. 3, 30 is a light source that irradiates the original 32, and the light reflected by the original 32 is transmitted to the optical system (mirror 50).
, 51 and lens 52) and is input to the CCD sensor 31 and converted into an electrical signal. The document 32 is conveyed by conveyance rollers 53, 5 driven by a document conveyance motor (not shown).
4, 55, and 56, the document 32 is transported in accordance with the reading speed. Note that 57 is a document loading table, and the plurality of documents 32 stacked on this loading table 57 are separated one by one by the cooperation of the conveying roller 54 and the pressing separation piece 58 and sent to the reading section 100. transported.

A control board 41 constitutes the main part of the control section 101, and various control signals are output from this control board 41 to each part of the apparatus. Further, 105 is a power supply unit that supplies power to each part, 106 is a modem board unit, and 107 is an NCU board unit that has a relay function with a telephone line.

Furthermore, FIG. 4 is a diagram showing details of the conveyance mechanism for the ink sheet 14 and the recording paper 11.

In the figure, reference numeral 24 rotates the platen roller 12 to move the recording paper 11 in the direction of arrow a (ink sheet 1
This is a motor for conveying recording paper in the direction of arrow b, which is opposite to the conveyance direction of No. 4). Further, 25 is an ink sheet conveyance motor for conveying the ink sheet 14 in the direction of arrow a by means of a capstan roller 71 and a pinch roller 72. Furthermore, 26 and 27 are transmission gears that transmit the rotation of the recording paper conveyance motor 24 to the platen roller 12;
73 and 74 are transmission gears that transmit the rotation of the ink sheet conveying motor 25 to the capstan roller 71. Further, 75 is a slip clutch unit.

Here, the ratio of gears 74 and 75 is adjusted so that the length of the ink sheet 14 wound on the take-up roll 18 by the rotation of the gear 75a is longer than the length of the ink sheet conveyed by the capstan roller 71. By setting , the ink sheet 14 conveyed by the capstan roller 71 is reliably wound onto the winding roll 18. Then, the ink sheet 1 is rolled by the take-up roll 18.
The slip clutch unit 75 absorbs an amount corresponding to the difference between the amount of the ink sheet 14 that is taken up by the capstan roller 71 and the amount of the ink sheet 14 that is fed by the capstan roller 71 . This makes it possible to suppress fluctuations in the transport speed (amount) of the ink sheet 14 due to fluctuations in the winding diameter of the winding roll 18.

FIG. 1 is a diagram showing electrical connections between a control section 101 and a recording section 102 in a facsimile apparatus according to an embodiment, and parts common to other drawings are designated by the same number.

The thermal head 13 is a line head. The thermal head 13 has a shift register 130 that inputs and holds one line of serial recording data 43a from the control unit 101 in synchronization with a shift clock 43b, and a latch signal 44 that causes the shift register 130 to
It includes a latch circuit 131 that latches data of 0, and a heating element 132 consisting of a heating resistor for one line. Here, the heating resistor 132 is divided into m blocks indicated by 132-1 to 132-m and driven.

Further, 133 is a temperature sensor attached to the thermal head 13 for detecting the temperature of the thermal head 13. The output signal 42 of this temperature sensor 133 is A/D converted in the control unit 101 and then
It is input to U113. As a result, the CPU 113 detects the temperature of the thermal head 13 and changes the pulse width of the strobe signal 47 in accordance with the temperature, or changes the driving voltage of the thermal head 13 in accordance with the characteristics of the ink sheet 14. The energy applied to the thermal head 13 is changed accordingly.

A black dot counter 134 counts the number of black dots (the number of recorded dots) included in one line of data. 43c is a counter clear signal output from the control section 101, and the count value of the counter 134 is reset to "0" by this signal 43c. This black dot counter 134 is connected to a shift memory 150 which will be described later.
When the shift clock 152 is outputted, if the recorded data 151 is black data "1", the count value is incremented by 1. This count value is transmitted to the control unit 1 through the signal line 134a.
01 is input. Therefore, after the control unit 101 transfers one line of recording data to the shift memory 150, by inputting the number of black dots via the signal line 134a,
It is possible to detect how many dots of black data are included in one line of print data output by the control unit 101.

150 is a shift memory whose details are shown in FIG.
and the serial recording data 151 are input, and the serial recording data 151 is sequentially shifted in in synchronization with the shift clock 152, and the line memories 150a to 150e (
A total of 5 lines of recording data can be stored in FIG. 11). After 5 lines of recorded data have been stored in this way, when new line data is shifted in,
Serial recording data already stored in this shift memory 150 is sequentially output to the thermal head 13. 1
54 indicates the serial recording data thus output to the thermal head 13, and 155 is a clock signal synchronized with this serial recording data 154, which is the same signal as the clock signal 152 here. Reference numeral 156 indicates a clear signal for clearing the contents of these line memories 150a to 150e.
The contents of 50 can be cleared to 0.

116 is a programmable timer, CP
The clock time is set by U113, and when the start of time measurement is instructed, the time measurement starts. Then, it operates to output an interrupt signal, a timeout signal, etc. to the CPU 113 at each instructed time.

The characteristics (type) of the ink sheet 14 may be determined by detecting the switch 103a of the operation section 103 described above or a mark printed on the ink sheet 14, or by detecting the mark printed on the ink sheet 14. The identification may be made based on marks, notches, protrusions, etc. attached to the cartridge or the like.

Reference numeral 46 indicates the thermal head 1 from the control unit 101.
This is a drive circuit that inputs a drive signal 47 and outputs a strobe signal 47 that drives the thermal head 13 in units of blocks. The drive circuit 46 can change the energy applied to the thermal head 13 by changing the voltage output to the power supply line 45 that supplies current to the heating element 132 of the thermal head 13 according to instructions from the control unit 101. 36 is a drive circuit that engages and drives the cutter 15;
Contains the motor for driving the cutter. 39 is a paper ejection motor that rotationally drives the paper ejection roller 16. 35,
Reference numerals 48 and 49 indicate the corresponding paper ejection motor 39, recording paper conveyance motor 24, and ink sheet conveyance motor 25, respectively.
This is a driver circuit that drives the rotation. Although these paper ejection motor 39, recording paper conveyance motor 24, and ink sheet conveyance motor 25 are stepping motors in this embodiment, they are not limited to this; for example, D
It may also be a C motor or the like.

<Description of recording process (Fig. 1, Fig. 5 to Fig. 1
0)> FIGS. 5 to 10 are flowcharts showing the image recording process for one page in the facsimile machine of this embodiment.
It is stored in M114.

This process starts when the facsimile received image signal is decoded, one line of image data to be recorded as an image is stored in the line memory 110, and a state is reached in which the image recording operation can be started. Here, it is assumed that the control unit 101 has determined by the switch 103a or the like that the multi-ink sheet is attached.

First, in step S1, a counter (PWLN) provided in the RAM 115 for counting the number of lines to be recorded by lowering the applied energy is cleared to "0", and the shift memory 150 is cleared by the clear signal 156. clear. Shift memory 15 in step S2
To check whether it is 0 full, set n to "5". Next, the process proceeds to step S3, where the counter clear signal 43c is
The black dot counter 134 is cleared to "0". Next, the process proceeds to step S4, where one line of recording data is serially output to the shift memory 150. When the transfer of one line of recording data is thus completed, the latch signal 44 is output in step S5, and the contents of the shift register 130 are stored in the latch circuit 131. However, after starting the recording operation, the first 5 lines of data are stored in the shift memory 150.
During this period, the data output to the thermal head 13 is all “0”, so the latch circuit 1
Recording data of all "0" is latched in 31.

Next, proceeding to step S6, the signal line 134a
The number of black dots of the one line data transferred to the shift memory 150 via the controller is inputted and stored in the black dot number memory 117 of the RAM 115. Next, in step S7, it is checked whether the contents of this black dot number memory 117 are "614" or more, and "
614" or more, the process advances to step S8 and checks whether the facsimile reception mode is the standard mode or the fine mode. If the facsimile reception mode is the fine mode, the recording paper 11 and the ink sheet 14 are fed in a small amount between each line, so the recording paper 11 and the ink sheet 14 are Since it is difficult for the recording paper 11 and the ink sheet 14 to stick together, the process advances to step S10, but in the standard mode, the conveyance amount of the recording paper 11 between each line is large, so the process advances to step S9, and the recording paper 11 and the ink sheet 14
In order to reduce sticking with the counter (PWLN
) is set to “5+3+1=9”. As a result, the five lines before and the three lines after the line in which the number of black dots is "614" or more are recorded by reducing the amount of energy applied to the thermal head 13. Next, proceed to step S10,
It is checked whether n is "0", that is, whether the shift memory 150 is full. If it is full, the process goes to step S14 (FIG. 6), and if it is not full, the process goes to step S46 (FIG. 9) to transfer the next line data. move on.

On the other hand, in step S7, the number of black dots is "61".
If the number is less than "4", the process advances to step S11, and n is "0".
If it is not "0", the process goes to step S46 (FIG. 9); if it is "0", the process goes to step S12, and it is checked whether the counter (PWLN) is "0". Counter (P
WLN) is “0”, step S50 (FIG. 10
), and recording is performed without reducing the energy applied to the thermal head 13. Also, the counter (PWLN
) is not "0", the process proceeds to step S13, the value of this counter is decremented by 1, and the process proceeds to step S15.

In step S14, a counter (PWLN
) is "0", and if it is "0", there is no need to reduce the energy applied to the thermal head 13, so the process advances to step S50 (FIG. 10) and normal recording is performed. On the other hand, if the value of the counter (PWLN) is not "0", the process advances to step S15, and the ink sheet 14 is
A conveying process for conveying the recording paper 11 by one line is started in step S16. As a result, as shown in the timing diagram of FIG. 12, the excitation phases of the ink sheet conveyance motor 25 and the recording paper conveyance motor 24 are switched slightly before the energization timing of the thermal head 13, and the excitation phases of the ink sheet conveyance motor 25 and the recording paper conveyance motor 24 are switched slightly before the energization timing of the thermal head 13. 14 are transported respectively.

The length of one line is set to approximately (1/7.7) mm in the facsimile machine of this embodiment, and the length of the ink sheet 14 is approximately 1/7.7 mm. It is conveyed by approximately (1/7.7s) mm. However, here, the value of s is set to about 5. Note that the conveyance lengths of the ink sheet 14 and the recording paper 11 can be realized by changing the number of excitation pulses of the recording paper conveyance motor 24 and the ink sheet conveyance motor 25, respectively. In this way, multi-printing can be achieved.

Next, the process proceeds to step S17, where one block of the heating resistor 132 of the thermal head 13 is energized to record an image. At this time, the power applied to drive the heating resistor 132 of the thermal head 13 to generate heat is determined by temperature data from the temperature sensor 133, and here, the pulse of the strobe signal is determined in accordance with the applied energy thus determined. The width P is changed. In the energization process of step S17, the strobe pulse width P is further reduced to 1/2 in order to reduce the energy applied to the thermal head 13. In this energization process, when recording in fine mode, all blocks are energized only once, and when recording in standard mode, all blocks are energized twice and recorded. Next, the process advances to step S18, where the thermal head 13
Check whether all blocks of the heating resistor 132 are energized.
If all blocks have not been energized yet, step S1
The process proceeds to step S9, and if all blocks of the thermal head 13 have been energized, the process proceeds to step S25 (FIG. 7).

In step S19, it is checked whether the generation of the next line of recording data has been completed (whether the reception of the next line has been completed and its decoding has been completed). If the generation of recording data for the next line has been completed, the process advances to step S21;
Otherwise, the process advances to step S20. Step S21
Then, it is determined whether this is the first process after the data generation for the next line is completed, and if so, the process advances to step S22 and the black dot counter 134 is cleared. Next step S2
3, the next line data is output to the shift memory 150. As a result, the black dot counter 134
The number of black dots on the output line is counted.

Note that if the generation of the next line data is not completed in step S19, the process advances to step S20, where the line data is received and decoded. Next step S
The process proceeds to step 24, where it is checked whether the energization time for that block has elapsed. A timer 116 determines whether this energization time has elapsed. Energization time (approx. 1200μs)
If the energization time has not elapsed, the process returns to step S19, but if the energization time has elapsed, the process returns to step S17 to execute the energization process for the next block. In this embodiment, the thermal head 13 includes 1024 heating resistors 132,
It is divided into 4 blocks (m=4:1 block is 506 dots) and driven with electricity, and the time required to record one line is approximately 5.0 ms (120 ms) in fine mode.
0 μs x 4 blocks), approximately 10 ms (1 block) in standard mode
200 μs×8 blocks).

When all blocks of the thermal head 13 have been energized and one line has been recorded in step S17, the process advances to step S25 to check whether the decoding process for one page of image data has been completed. If the decoding process for one page has not been completed, the process advances to step S40 (FIG. 7). On the other hand, when the decoding process for one page is completed, the process advances to step S26, and in order to print the 5 lines of recorded data stored in the shift memory 150, a process of outputting dummy data to the shift memory 150 and printing is performed. conduct.

That is, in step S26, the shift memory 15
Set the number of 0 line memories “5” to counter k,
In step S27, it is checked whether the value of the counter (PWLN) is "0", that is, whether it is necessary to lower the energy applied to the thermal head 13. If this is necessary, the process proceeds to step S31, where one line of dummy data (for example, data of all "0") is output to the shift memory 150, and when the output of this dummy data is completed, the latch signal 44
Output. Next, in step S32, the counter (PWLN
) is -1, and in steps S33 and S34, the heating resistor 13 is
2, each block is energized.

[0045] Also, in step S27, the thermal head 13
When there is no need to reduce the energy applied to Recording is performed by energizing with width P. The pulse width P of this strobe signal is the pulse width of the strobe signal determined based on the temperature of the thermal head 13, etc., as explained in connection with step S17 above.

In this way, in steps S35 and S36, when all of the five lines of recording data stored in the shift memory 150 are discharged to the thermal head 13, the process proceeds to step S3.
7, a predetermined amount of the recording paper 11 is transferred to the paper ejection roller 16 (16a).
a, 16b). And step S3
8 to drive and engage the cutters 15 (15a, 15b),
The recording paper 11 is cut into pages. and discharge roller 16
The cut recording paper 11 is discharged from the apparatus, and in step S39, the remaining recording paper 11 is returned by a distance corresponding to the distance between the thermal head 13 and the cutter 15.
The recording process for one page ends.

On the other hand, if it is determined in step S25 that the decoding process for one page of image data is not completed, the process proceeds to step S40, where it is checked whether the transfer of the next line data to the shift memory 150 has been completed, and whether or not it has been completed is determined. Then, the process returns to step S5, outputs the latch signal 44, and executes the above-described process.

On the other hand, if it is determined in step S40 that the transfer of the next line data has not been completed, the process advances to step S41 to check whether the generation of the next line data has been completed, and if the generation has not been completed, the process proceeds to step S42. The process proceeds to , and continues receiving and decoding the next line data. Step S41
If the generation of the next line data is completed in step S4
3, it is checked whether this is the first processing after the next line data generation, as in step S19, and if it is the first processing, the black dot counter 134 is cleared in step S44, as in step S21. Next step S
45, the generated next line data is transferred to the shift memory 150, and the process returns to step S5.

Further, if the value of n is not "0" in step S10 (FIG. 5), that is, if line data is not stored in all of the line memories 150a to 150e of the shift memory 150, step S46 (FIG. 5) is performed. Proceed to 9) and n
At the same time, in step S47, the counter (P
It is checked whether the value of WLN) is "0", and if it is not "0", the value of the counter is decremented by 1 (step S48). and,
In step S49, wait for the generation of the next line data to finish,
When the process is completed, the process advances to step S3 (FIG. 5), and the above-described process is executed. In this way, the thermal head 1 is operated until the value of n becomes "0" in step S10 or step S11.
3, no recording is performed and only data transfer to the shift memory 150 is performed.

Further, in step S12 of FIG.
WLN) becomes "0", step S50 (FIG. 10
), and one line is recorded in the same manner as in steps S15 to S24 (FIG. 6) described above. However, step S
In the energization process at 52, since there is no need to reduce the energy applied to the thermal head 13, the pulse width of the strobe signal that drives the thermal head 13 to generate heat is set to P.
It is said that

According to this embodiment, when the number of recorded dots (number of black dots) on a certain line is greater than or equal to a predetermined value, a predetermined line before that line and a predetermined line after that line are recorded. By lowering the energy applied to the thermal head 13 when printing, the amount of heat stored in the thermal head 13 when recording a line with a large number of black dots is reduced. This has the effect of reducing the amount of ink on the ink sheet 14 that is melted at one time, reducing the shearing force between the inks in the ink layer, and improving the separation of the ink sheet 14 and recording paper 11 during conveyance. .

FIG. 12 is a timing diagram showing the timing of energizing the thermal head 13 and the timing of transporting the ink sheet 14 and recording paper 11 in the facsimile machine of this embodiment. It is divided into blocks and energized, and each of the strobe signals 0 to 3 is transmitted to the thermal head 13.
It corresponds to the energization signal of each block. Note that the recording operation timing in the standard mode is shown here, and the conveyance of the recording paper 11 and ink sheet 14 is performed by switching the phase excitation of each motor (1/2 half step) when a pulse is generated. 11 is 1 in 4 half steps
/7.7 mm, and the ink sheet 14 is conveyed 1/7.7 smm (s=5) in four half steps.

FIG. 13 shows that the control section 101 controls the shift memory 15.
This is a diagram showing the relationship between the recorded data transferred to the line 0 and the recorded data shifted out from the shift memory 150 and transferred to the thermal head 13. The numbers in parentheses indicate the number of black dots included in the line. ing.

At timing T1, the recording data up to line 11 is transferred to the shift memory 150, and the recording data of line 6, which was transferred and stored in the shift memory 150 five lines before, is transferred to the thermal head 13 and recorded. It shows the timing when it becomes possible. At this timing T1, in order to convey the ink sheet 14 and the recording paper 11, the excitation phase of each motor is switched and each motor is driven in half steps. Since there is a time delay after the motors are switched to phase excitation until the recording paper 11 and ink sheet 14 are actually conveyed, these motors are started to be driven before the recording operation begins. Next, line 6 is recorded. 1 transferred to the shift memory 150 at this time.
The number of black dots in the line data (line 11) is "300" from FIG. 13, which is less than "614", so the energy applied to the thermal head 13 is not reduced and is recorded with the normal strobe pulse width P. is executed.

At timing T2, the recording data of line 12 is transferred to the shift memory 150, and the thermal head 1 is transferred to the shift memory 150.
3 shows the timing when the recording data of line 7 is transferred and becomes recordable. At this time, the number of black dots on line 12 is "700" which is more than "614", so
The pulse width of the strobe signal applied to the thermal head 13 is set to P/2. As a result, the number of black dots is “
The 5th line before line 12 that is 614” dots or more (
From line 7) to the third line (line 15) after line 12, the pulse width of the strobe signal is set to P/2.
and recorded. This counting of the number of lines is performed by the aforementioned counter (PWLN). Then, when recording line 16, the number of black dots of line 21 transferred to shift memory 150 at this time is "230", so
Recording is performed with the pulse width P of the original strobe signal. <Description of Recording Principle (FIG. 14) FIG. 14 is a diagram showing an image recording state when an image is recorded with the conveyance directions of the recording paper 11 and the ink sheet 14 reversed in this embodiment.

As shown in the figure, a recording paper 11 and an ink sheet 14 are held between the platen roller 12 and the thermal head 13, and the thermal head 13 is pressed against the platen roller 12 with a predetermined pressure by a spring 21. There is. Here, the recording paper 11 is conveyed in the direction of arrow b at a speed VP by rotation of the platen roller 12. On the other hand, the ink sheet 14 is conveyed in the direction of arrow a at a speed VI by the rotation of the ink sheet conveyance motor 25.

Now, the heating resistor 1 of the thermal head 13
When the ink sheet 32 is heated by being energized by the power source 105, the portion of the ink sheet 14 shown by the shaded area 81 is heated. Here, 14a is a base film of the ink sheet 14;
b indicates the ink layer of the ink sheet 14. Ink layer 8 heated by energizing heating resistor 132
The ink 1 is melted, and a portion 82 of it is transferred onto the recording paper 11. This transferred ink layer portion 82 corresponds to approximately 1/s (s>1) of the ink layer indicated by 81.

At the time of this transfer, it is necessary to generate a shearing force on the ink at the boundary line 83 of the ink layer 14b so that only the portion indicated by 82 is transferred onto the recording paper 11. In this case, by increasing the relative speed between the ink sheet 14 and the recording paper 11, the ink layer to be transferred can be reliably peeled off from the ink sheet 14. [Description of Ink Sheet (FIG. 15)] FIG. 15 is a cross-sectional view of the ink sheet used for multi-printing in this embodiment, which is composed of four layers.

First, the second layer is a base film that serves as a support for the ink sheet 14. In the case of multi-printing, heat energy is applied to the same location many times, so aromatic polyamide films and capacitor paper with high heat resistance are advantageous, but conventional polyester films can also be used. Considering the role of a medium, it is advantageous for the thickness of these materials to be as thin as possible in terms of printing quality, but from the viewpoint of strength, 3 to 8 μm is preferable.

The third layer is an ink layer containing an amount of ink that can be transferred onto a recording paper (recording sheet) s times. This component is mainly composed of resins such as EVA as an adhesive, carbon black and nigrosine dyes for coloring, carnauba wax and paraffin wax as binding materials, and is formulated to withstand s times of use in the same location. has been done. The coating amount is preferably 4 to 8 g/m2, but the sensitivity and density vary depending on the coating amount, and can be selected arbitrarily.

[0061] The fourth layer is the part where no recording is performed, and there is a third layer on the recording paper.
This is a top coating layer to prevent pressure transfer of the ink in the layer, and is made of transparent wax or the like. As a result, only the transparent fourth layer is pressure-transferred, and it is possible to prevent background smudges on the recording paper. The first layer is a heat-resistant coating layer that protects the base film of the second layer from the heat of the thermal head 13. This is suitable for multi-printing where thermal energy for s lines may be applied to the same location (when black information is continuous), but whether or not to use it can be selected as appropriate. It is also effective for base films with relatively low heat resistance, such as polyester films.

Note that the structure of the ink sheet 14 is not limited to this embodiment, and may consist of, for example, a base layer and a porous ink-retaining layer containing ink provided on one side of the base layer. Alternatively, a heat-resistant ink layer having a microporous network structure may be provided on a base film, and the ink may be contained in the ink layer. Also,
The material of the base film may be, for example, a film or paper made of polyamide, polyethylene, polyester, polyvinyl chloride, triacetylcellulose, nylon, or the like. Furthermore, although the heat-resistant coating layer is not necessarily required, its material may be, for example, silicone resin, epoxy resin, fluorine resin, etrocellulose, or the like.

In this embodiment, when recording in the fine mode, all blocks of the thermal head 13 are energized once for recording, but as in the standard mode, the recording is performed in multiple times. It may be energized. Also, in this fine mode, the energy applied to the thermal head 13 is not reduced even if the number of black dots in one line is "614" or more, but the energy applied to the thermal head 13 may be reduced as in the standard mode. Alternatively, the number of lines for reducing the applied energy may be reduced compared to the standard mode.

Further, in the above embodiment, the applied energy was controlled by reducing the pulse width of the strobe signal to 1/2, but the amount of the pulse width is not limited to this embodiment. For example, the applied energy may be reduced by controlling the voltage applied to the thermal head 13 instead of the pulse width of the strobe signal.

Furthermore, the recording paper 11 is 1/7.7 mm,
Although the ink sheet 14 is conveyed by 1/7.7 smm, the corresponding motor is conveyed in four steps, but the number of steps is not limited to this.

Furthermore, in this embodiment, when the number of black dots in one line is "614" or more, the energy applied to the thermal head is lowered when recording the lines before and after it. The number of black dots used is “6”
The applied energy is not limited to 14", and the applied energy is also controlled by gradually decreasing the applied energy from the few lines before the line containing a large number of black dots to record the corresponding line with the minimum applied energy. , the applied energy may be gradually increased when recording each subsequent line.

The heating method used in the thermal transfer printer is not limited to the above-mentioned thermal head method using a thermal head, and for example, an energization method or a laser transfer method may be used.

Further, in this embodiment, an example in which a thermal line head is used has been described, but the present invention is not limited to this, and a so-called serial type thermal transfer printer may also be used. Further, although the present embodiment has been described in the case of multi-printing, the present invention is not limited to this, and it goes without saying that the present invention can also be applied to the case of ordinary thermal transfer recording using a one-time ink sheet.

Further, in the above-described embodiments, the thermal transfer printer is applied to a facsimile machine, but the present invention is not limited to this. For example, the thermal transfer recording device of the present invention can be applied to a word processor, a typewriter, or a facsimile machine. It can also be applied to copying devices, etc.

Further, the recording medium is not limited to recording paper, and may include cloth, plastic sheets, etc. as long as it is made of a material that allows ink transfer. Furthermore, the ink sheet is not limited to the roll configuration shown in the embodiment, but may be of the so-called ink sheet cassette type, in which the ink sheet is built into a housing that is removable from the main body of the recording apparatus, and the housing is removable from the main body of the recording apparatus. etc. may be used.

As explained above, according to this embodiment,
In a thermal transfer printer, the applied energy is reduced from a predetermined number of lines before a line that contains a predetermined number of black dots or more, and after that line is recorded, the energy applied to the thermal head is reduced when recording a predetermined number of lines. By doing so, the ink sheet 14 and the recording paper 11 can be easily separated.

Furthermore, this embodiment is effective in a recording apparatus such as a facsimile machine in which there is a possibility that the recording period may become uneven due to the time interval of one line of image data or the decoding processing time thereof.

[0073]

As explained above, according to the present invention, by lowering the energy applied to the recording head when recording a plurality of lines before or after a line containing a predetermined number of black dots, This has the effect of reliably separating the ink sheet from the recording medium after image recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing electrical connections between a control section and a recording section in a thermal transfer recording apparatus according to an embodiment.

FIG. 2 is a block diagram showing a schematic configuration of a facsimile machine according to an embodiment.

FIG. 3 is a side cross-sectional view showing a mechanical part of the facsimile apparatus according to the embodiment.

FIG. 4 is a diagram showing a conveyance mechanism for recording paper and ink sheets in an embodiment.

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

FIG. 10 is a flowchart showing one page recording processing in the facsimile machine of this embodiment.

FIG. 11 is a block diagram showing the configuration of a shift memory of this embodiment.

FIG. 12 is a timing chart showing the timing of energizing the thermal head and the timing of transporting the ink sheet and recording paper in the recording process of the facsimile apparatus of this embodiment.

FIG. 13 is a diagram showing the relationship between data transferred to the shift memory and data transferred to the thermal head in this embodiment.

FIG. 14 is a diagram showing the principle of multi-printing during recording in this embodiment.

FIG. 15 is a diagram showing the cross-sectional shape of the multi-ink sheet used in this example.

[Explanation of symbols]

10 Rolled recording paper 10b Roll paper loading section 11 Recording paper 12 Platen roller 13 Thermal head 14 Ink sheet 17 Ink sheet supply roll 18 Ink sheet take-up roll 19 Sheet sensor 24 Recording paper conveyance motor 25　Ink sheet conveyance motor 100 Reading section 101 Control section 102 Recording Department 103 Operation section 104 Display section 110 Line memory 111 Encoding/decoding section 113 CPU 114 ROM 115 RAM 116 Timer 117 Black dot memory 132 Heating resistor (heating element) 134 Black dot counter 150 Shift memory

Claims (5)

[Claims] 1. A thermal transfer recording apparatus that records an image on the recording medium by transferring ink contained in an ink sheet to the recording medium, the apparatus comprising: an ink sheet conveying means for conveying the ink sheet; a recording medium conveying means for conveying; a recording means for recording an image on the recording medium line by line by acting on the ink sheet; and a counting means for counting the number of black dots in a line recorded by the recording means; control means for controlling the recording means to record with lower energy applied to the recording means than a line before the line by a predetermined number, including a line in which the number of black dots counted by the counting means is greater than or equal to a predetermined number; A thermal transfer recording device comprising: 2. The control means is further configured to record a predetermined number of lines following a line in which the number of black dots counted by the counting means is equal to or greater than a predetermined number by reducing the energy applied to the recording means. The thermal transfer recording device according to claim 1, characterized in that: 3. A facsimile machine using a thermal transfer recording device that records an image on the recording medium by transferring ink contained in an ink sheet to the recording medium, the facsimile machine comprising an image input means for inputting a document image; a transmitting/receiving means for transmitting and receiving signals; a recording data creating means for creating recording data by inputting the image input means or the image signal from the transmitting/receiving means; an ink sheet conveying means for conveying the ink sheet; and the recording medium. a recording medium conveying means for conveying the ink sheet; a recording means for recording an image on the recording medium line by line by acting on the ink sheet conveyed by the ink sheet conveying means based on the recording data; a counting means for counting the number of black dots included in one line; and an application to the recording means from a predetermined number of lines before the line, including a line in which the number of black dots counted by the counting means is equal to or greater than a predetermined number. 1. A facsimile apparatus comprising: control means for controlling recording with lower energy. 4. The control means is further configured to record a predetermined number of lines following a line in which the number of black dots counted by the counting means is equal to or greater than a predetermined number by reducing the energy applied to the recording means. The facsimile machine according to claim 3, characterized in that: 5. A thermal transfer recording method in which ink contained in an ink sheet is transferred to a recording medium to record an image on the recording medium, wherein the number of black dots in each line of recording data recorded line by line is calculated. and, when the number of black dots is a predetermined number or more, a step of reducing the energy applied to the recording head when recording a predetermined number of lines before that line and/or a predetermined number of lines following that line. A thermal transfer recording method comprising: