JPH03146362A - Thermal recording device and facsimile device using the same device - Google Patents

Abstract

PURPOSE:To make recording possible using a thermal head without a heat history control circuit by a method wherein while printing a first sheet of the same picture information, temperature information of a thermal head for respective lines is detected, and an energy to be applied at the time of printing of a second sheet forth is determined. CONSTITUTION:When a plural number of sheets of the same image are printed, when a first sheet is recorded, data from a temperature sensor 133, which detects a temperature of a thermal head 13, is stored in a temperature data area in a RAM 115 for respective lines, and an appropriate pulse width data to the data for all the lines is read and decided from a table in a ROM 114. In this table, head driving pulse width information which corresponds with temperature rising of the thermal head 13 is stored, and at the time of recording process of a second sheet forth, referring to the temperature data which is stored in the temperature data area, the driving pulse width of the thermal head 13 for each line is decided, and recording is performed. Even with a thermal head which does not have a heat history control circuit, influence such as accumulation of heat, etc., can be reduced.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a thermal recording device that records an image on a recording medium by transferring ink contained in an ink sheet to a recording medium, and a facsimile device using the thermal recording device. It is something.

[Prior art] Generally, thermal transfer printers use an ink sheet with heat-melting (or heat-sublimation, etc.) ink applied to a base film, and a thermal head selectively heats the ink sheet in response to image signals. Then, images are recorded by transferring the molten ink onto recording paper. When such a device outputs the same image information on multiple sheets, a control method called thermal history control based on the heat storage effect of the thermal head or previous line information is used to determine the pulse width applied to the thermal head and improve the image quality. Improvements have been made in the past.

[Problems to be Solved by the Invention] However, the thermal history control in the conventional example described above is usually achieved by a control circuit built into the thermal head, and therefore it is not sufficient because it largely depends on the circuit configuration within the individual thermal head used. Not only is it not possible to obtain a good effect, but there is a risk that problems such as deterioration of image quality may occur depending on the image pattern to be recorded. Further, a thermal head equipped with such a thermal history control circuit is more expensive than a normal thermal head, and the use of such a thermal head has the problem of increasing the cost of the apparatus.

The present invention has been made in view of the above conventional example, and when printing multiple sheets of the same image information, the temperature information (heat storage data) of the thermal head for each line is detected while printing the first sheet. Then, by determining the energy applied to the thermal head when printing the second and subsequent pages from this data, even if a thermal head without a thermal history control circuit is used, recording can be performed with optimal thermal history control. An object of the present invention is to provide a thermal recording device that can perform the following operations, and a facsimile device using the device.

[Means for Solving the Problems] In order to achieve the above object, the thermal recording device of the present invention has the following configuration. That is.

A thermal recording device that records an image on a recording medium by driving a thermal head to generate heat in accordance with image data, comprising a storage means for storing image data and an instruction to record multiple copies of the same image data. means, a recording means for recording a plurality of image data sheets in response to instructions from the instruction means, and recording means for recording temperature information of the thermal head at the time of recording the first sheet by the recording means, of the image data. Based on the temperature information storage means stored in correspondence with each line and the temperature information stored in the temperature information storage means, the energy applied to the thermal head in recording the second and subsequent images is determined to generate heat. and control means for driving.

In order to achieve the above object, a facsimile apparatus according to another invention has the following configuration. That is, it is a facsimile machine equipped with a thermal recording device that records an image on a recording medium by driving a thermal head to generate heat in accordance with image data,
a storage means for storing image data read by a document reading unit or image data received; an instruction means for instructing the image data stored in the storage means to be continuously duplicated on a plurality of sheets; and an instruction from the instruction means. recording means for continuously recording image data on a plurality of sheets corresponding to the image data, and temperature information of the thermal head at the time of recording by the recording means and at the time of recording the first sheet, corresponding to each line of the image data; a temperature information storage means for storing temperature information; and a control means for determining the energy to be applied to the thermal head in recording the second and subsequent images based on the temperature information stored in the temperature information storage means and driving the thermal head to generate heat. have

[Function] When the thermal recording device configured as described above is instructed to record multiple sheets of the same image data, it corresponds the temperature information of the thermal head during recording of the first sheet to each line of the image data. Based on the stored temperature information, the energy to be applied to the thermal head in recording the second and subsequent images is determined, and the thermal head is operated to generate heat.

In addition, facsimile machines with other configurations store image data read by the original reading unit or received image data, and when instructed to continuously reproduce the stored image data on multiple sheets. , image data can be recorded continuously on multiple sheets. When recording this copy,
The temperature information of the thermal head when recording the first sheet is
It is stored in correspondence with each line of the image data, and based on the stored temperature information, the energy to be applied to the thermal head for recording the second and subsequent images is determined, and the thermal head is driven to generate heat. It works like that.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Explanation of the facsimile machine (Fig. 1 1, Fig. 2)〉Part 1
This figure and FIG. 2 are schematic block diagrams showing an example in which the thermal transfer printer of the embodiment is applied to a facsimile machine.

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

In the figure, lOO is a reading unit that photoelectrically reads an original and outputs it as a digital image signal to the control unit 101, and is equipped with an original transport motor, a COD image sensor, and the like. The digital image signal output from the reading section 1100 is stored in the image memory 110 of the control section 101. Next, regarding the configuration of the control unit 101, 110 is an image memory that stores image data of each line of image data, and when transmitting or copying an original image, image data output from the reading unit 100 is stored. When receiving image data, received image data decoded by an encoding/decoding unit 111, which will be described later, is stored.

Then, by outputting the data stored in the image memory 110 to the recording unit 102, an image is formed on a recording medium such as recording. 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, the control unit 101 includes a control program for the CPU 113 and various data (for example, pulse width information for driving the thermal head 13 to generate heat,
A ROM1I that stores a table 114a, etc. that stores energization pulse information corresponding to the temperature information of No. 3, etc.)
4. The RAM 115 is used as a work area for the CPU 113 and also stores various data (for example, temperature data 115a of the thermal head 13 during each line recording).

A recording unit 102 includes a thermal head 13 and a temperature detection means for the thermal head 13, and records an image on recording paper using a thermal transfer recording method. This configuration will be described in detail later with reference to FIG.

103 is a key for instructing various functions such as starting transmission; a multi-copy key 103 for instructing to record multiple copies of the same image;
a. It is an operation section equipped with a key for specifying the number of sheets, a key for entering a telephone number, etc.

Reference numeral 104 is usually a display section such as a liquid crystal, which is 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. In addition, 106 is a modem (modulator/demodulator), 10
7 Network control unit (NCU) that controls communication with communication lines
, 108 is a telephone.

FIG. 1 shows a control unit 10 in a facsimile machine according to an embodiment.
1 and the recording unit 102, and parts common to other drawings are indicated by the same numbers.

In FIG. 1, the thermal head 13 is a line head that includes a plurality of heating elements 132 in the width direction of the paper.

This thermal head 13 has a shift register 130 for inputting and storing one line of serial recording data 37 and shift clock 43 from the control unit 101.
．． A latch circuit 131 that latches data in the shift register 130 by a latch signal 44 is provided with 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.

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 transmitted to the control unit 1
A/D conversion is performed within 01 and input to the CPU 113.

As a result, the CPU 113 detects the temperature of the thermal head 13 and changes the pulse width of the strobe signal 47 or changes the driving voltage of the thermal head 13 output to the power line 45 in accordance with the detected temperature. , it is possible to control the energy applied to the thermal head 13 according to the characteristics of the ink sheet.

In this embodiment, when recording a plurality of identical images, when recording the first image, data from the temperature sensor 133 that detects the temperature of the thermal head 13 is stored in the temperature data area 115a of the RAM 115 for each line. Store it. Appropriate pulse width data for the full in data is read out from the table 114a of the ROM 114 and determined. This table 114a stores head drive pulse width information corresponding to the temperature rise of the thermal head 13, and when recording the second and subsequent sheets, the temperature data stored in the temperature data area 115a is stored. With reference to this, the driving pulse width of the thermal head 13 for each line is determined and recording is performed. In addition, in this example,
A thermistor is used as the temperature sensor 133.

Reference numeral 46 denotes a drive circuit that inputs a drive signal for the thermal head 13 from the control unit 101 and outputs a strobe signal 47 for driving the thermal head 13 in units of blocks. Note that this drive circuit 46 changes the voltage output to the power supply line 45 that supplies current to the heating element 132 of the thermal head 13 in accordance with instructions from the control unit 101 to control the thermal head 13.
The applied energy of can be changed. 36 is a drive circuit for driving the cutter 15 to mesh;
Contains the motor for driving the cutter.

39 is a paper ejection motor that rotationally drives a paper ejection roller. 35, 48, and 49 are the corresponding paper ejection motors 3
9. A driver circuit for rotationally driving each of the recording paper conveyance motor 24 and the ink sheet conveyance motor 25. Although these paper ejection motor 39, recording paper delivery motor 24, and ink sheet conveyance motor 25 are stepping motors in this embodiment, they are not limited to this, and may be DC motors, for example. good.

[Description of recording processing during multi-copying (FIG. 3)] FIG. 3 is a flowchart showing recording processing during multi-copying according to the present invention, and a control program for executing this processing is stored in the ROM 114. This process is started when one page of image data is stored in the image memory 110 and the multi-copy key 103a of the operation unit 103 is pressed.

First, in step S1, one line of recording data is transferred from the image memory 110 to the shift register 1 of the thermal head 13.
Transfer serially to 30. Then, in step S2, the latch signal 44 is output, and the transferred recording data for one line is stored in the latch circuit 131. Then, in step S3, the ink sheet conveyance motor 25 is driven to convey the ink sheet by one line. Furthermore, in step S4, the recording paper transport motor 24 is driven to transport the recording paper by one line.

Next, the process proceeds to step S5, where one block 132-1 of the thermal head 13 is energized to generate heat and perform recording in one block. At this time, if it is the first recording, the ROM
The current application time to the thermal head 13 is determined based on the pulse width data stored in the table 114a of 114. Then, in step S6, it is checked whether all m blocks of the thermal head 13 have been energized, and if the energization of m blocks has not been completed, the process returns to step S5 and the next block is energized. In this way, in step S6, when the m blocks are energized and the recording of one line is completed, the process proceeds to step S7, and it is determined whether or not the recording process is for the first sheet.

When recording the first sheet, the process advances to step S8, and the temperature data measured by the temperature sensor 133 at the time of recording of each line is stored in the area 115a of the RAM 115. Next, in step S9, it is checked whether recording of one page has been completed, and if it has not been completed, the process returns to step S1 and the above-described processing is executed.

On the other hand, if it is determined in step S7 that the recording process is not for the first sheet, the process advances to step S9.

When the recording process for one page is completed in step S9, step S9
10, the recording paper transport motor 24 is driven to transport the recording paper by a predetermined amount, and in step Sll, the cutter 15 is driven to cut off the recorded portion of the recording paper. Then, the cut recording paper is ejected, and in step S12, the recording paper is returned by a predetermined amount.
Return to standby position. Then, the process advances to step S13, and it is determined whether recording for the specified number of schools inputted in advance from the operation unit 103 has been completed. If it has finished, the multi-copy recording process ends there.

If it has not been completed yet, the process advances to step S14 to see if the next recording is the second recording. If it is the second one, step S
Step 15, the pulse width to be used from now on is stored in ROM11.
4 pulse width data of table 114a and RAM 11
It is determined from the energization pulse width for each line of the thermal head 13 based on the temperature information stored in the temperature data 115a of No. 5. Then, the process advances to step S1. Note that if it is the third or subsequent sheet, the process of step S15 is not necessary, and the pulse width information determined in step S15 during the recording process of the second sheet is used as is, and the process moves from step Sl.

Here, the temperature data 115a stored in the RAM 115
As a method of calculating the pulse width data for the second and subsequent sheets based on
The energization pulse width for each line may be determined based on the optimum head energization pulse information corresponding to the temperature information of the thermal head 13 when recording each line. Alternatively, the energy applied to the thermal head 13 may be reduced in lines where the temperature information of each line is equal to or higher than a predetermined value. Note that the energy applied to the thermal head 13 may be adjusted not only by changing the drive pulse width as described in this embodiment, but also by changing the voltage applied to the thermal head 13, for example.

In the above-described embodiment, the temperature of the thermal head 13 at the end of recording for each line is detected.
In step S6, the temperature of the thermal head 13 (each block) is detected every time the energization of each block is completed, and the energization time (applied energy) to each block of the thermal head 13 is determined based on the temperature information. You can also do this.

As explained above, according to this embodiment, when recording multiple sheets of the same image data continuously, such as in multi-copying, even if a thermal head without a thermal history control circuit is used, the heat storage It is possible to write optimally by reducing the influence of such factors.

This embodiment is effective for facsimile machines equipped with a thermal head, particularly for facsimile machines having a multi-copy function.

Although the present embodiment has been described in the case of a thermal transfer printer, the present invention is not limited thereto, and can be applied to, for example, a thermal printer that records on thermal recording paper.

[Effects of the Invention] As explained above, according to the present invention, when printing multiple sheets of the same image information, the temperature information (heat storage data) of the thermal head for each line is recorded while printing the first sheet. ) and determine the energy to be applied to the thermal head when printing the second and subsequent pages from that data.
Even if a thermal head without a thermal history control circuit is used, it is possible to perform recording with optimal thermal history control.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the electrical connection between the control section and the recording section of this embodiment, FIG. 2 is a block diagram showing the schematic configuration of the facsimile machine of this embodiment, and FIG. 3 is a diagram showing the facsimile machine of this embodiment. 3 is a flowchart showing recording processing in the apparatus. In the figure, 13... thermal head, 15... cutter. 19... Ink sheet sensor, 24... Recording paper conveyance motor, 25... Ink sheet conveyance motor, 35
．． 48.49... Driver circuit, 36... Drive circuit, 39... Paper ejection motor, 43... Shift clock, 44... Latch signal, 100... Reading section, 101
...Control circuit, 102...Recording section, 103...Operation section, 103a...Multi-copy key 104...
Display section, 105... Power supply section, 106... Modem, 1
07...NCU, 110...Image memory, 111.
... Encoding/decoding unit, 112... Buffer memory,
113...CPU, IL4-ROM, 114
a-table, 115...RAM, 115a...
Temperature data, 132...Heating resistor. Patent applicant Canon Co., Ltd.

Claims (2)

[Claims] (1) A thermal recording device that records an image on a recording medium by driving a thermal head to generate heat in accordance with image data, the device comprising a storage means for storing image data, and a device for recording multiple copies of the same image data. an instruction means for instructing; a recording means for recording image data on a plurality of sheets in response to an instruction from the instruction means; Temperature information storage means for storing data corresponding to each line; and based on the temperature information stored in the temperature information storage means,
A thermal recording apparatus comprising: a control means for determining the energy applied to the thermal head in recording images on the second and subsequent sheets and driving the thermal head to generate heat. (2) A facsimile machine equipped with a thermal recording device that drives a thermal head to generate heat in accordance with image data and records an image on a recording medium, which is capable of transmitting image data read by a document reading section or received image data. a storage means for storing, an instructing means for instructing to successively reproduce a plurality of copies of the image data stored in the storage means, and a plurality of consecutive copies of the image data in response to instructions from the instructing means; a recording means; a temperature information storage means for storing temperature information of the thermal head at the time of recording by the recording means and when recording a first sheet in correspondence with each line of the image data; and the temperature information storage means; Based on the stored temperature information,
A facsimile apparatus comprising: a control unit that determines the energy applied to the thermal head in recording images on a second and subsequent sheets and drives the thermal head to generate heat.