JPH03153369A - Recorder - Google Patents

Abstract

PURPOSE:To stabilize the recording density for recording an image on a recording medium by a method wherein the temperature changing state of a recording head is obtained by a temperature sensor, and the energy to be applied to the recording head is controlled based on the temperature changing state. CONSTITUTION:The temperature information (T) of a thermal head 13 detected by a temperature sensor 20 is input and stored in a memory 115a(M) through an A/D converter 18. After a specified time has passed, the temperature data (T1) from the A/D converter 18 are input again. Then, the temperature data (T1) are corrected by T1 + (T1 + M) and the corrected temperature data (T1) are stored in a memory 115b. Thus, the temperature changing values (T1 -M) of the thermal head 13 are added to the latest temperature data (T1) after specified time has passed since M is measured, so that the pulse width applied to the recording head 13 is determined based on the corrected temperature information (T1).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording apparatus that records an image on a recording medium by driving a recording head such as a thermal head using heat.

[Prior Art] In conventional thermal printers that record images by driving a thermal head to generate heat, the thermal head is equipped with a temperature sensor such as a thermistor to detect the temperature of the thermal head, and the output of the temperature sensor is The energy applied to the thermal head is adjusted accordingly. This involves, for example, inputting an analog signal from a temperature sensor, converting it into digital data, and determining the pulse width to be applied to the thermal head by referring to a table that stores the applied pulse width corresponding to the digital value. This is done by

[Problems to be Solved by the Invention] However, the temperature sensor is generally installed at a location slightly apart from the heating element array due to the structure of the thermal head.

For this reason, the temperature of the thermal head is detected by the temperature sensor later than the actual temperature change of the heating element.
It has been insufficient to simply adjust the energy applied to the thermal head based on the output of the temperature sensor.

The present invention has been made in view of the above conventional example, and stabilizes the recording density by determining the temperature change state of the print head using a temperature sensor and controlling the energy applied to the print head based on the temperature change state. An object of the present invention is to provide a recording device that can record an image on a recording medium.

[Means for Solving the Problems] In order to achieve the above object, the recording device of the present invention has the following configuration. That is, it is a recording apparatus that records an image on a recording medium by driving a recording head to generate heat, and includes a temperature detection means for detecting the temperature of the recording head, and a temperature detection means for detecting the temperature detected by the temperature detection means after a time. determining means for determining energy to be applied to the recording head based on a state of change of information; and driving the recording head to generate heat based on the applied energy determined by the determining means to record an image on a recording medium. and a recording means for recording.

[Operation] In the above configuration, the temperature of the print head is detected at intervals, and the energy to be applied to the print head is determined based on the state of change of the temperature information of the print head, and
Based on the determined applied energy, the recording head is driven to generate heat to record an image on the recording medium.

[Example] Hereinafter, a preferred embodiment of the present invention will be explained in detail with reference to the accompanying drawings.In this example, a thermal printer using a thermal head will be explained as an example. The invention is not limited to this, and can of course be applied to, for example, a bubble inkjet printer that records an image by ejecting ink droplets using heat generation.

[Description of facsimile machine (Figs. 1 to 4)] Figs. 1 and 2 are diagrams showing an example in which a thermal transfer printer using an embodiment of the present invention is applied to a facsimile machine. FIG. 2 is a block diagram showing a schematic configuration of the facsimile machine, and FIG. 2 shows a side sectional view of the facsimile machine.

First, the schematic configuration will be explained based on FIG. 1.

In the figure, 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 COD image sensor, and the like. Reference numeral 101 denotes a control unit that controls the entire apparatus, and its configuration will be explained below. 110 is a line memory for storing image data of each line of image data; when transmitting or copying a document, one line of image data from the reading section 100 is stored; when receiving image data, it is decoded; One line of received image data is stored. Image formation is then performed 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 and the entire device are controlled by a CPU 113 such as a microprocessor. In addition to the CPU 113, the control unit 1.1 includes a ROM 114 that stores control programs and various data for the CPU 113, and a RAM 115 that temporarily stores various data as a work area for the CPU 113.

Reference numeral 114a denotes a table provided in the ROM 114, which stores information on pulse widths applied to the thermal head 13 in accordance with temperature information (digital value) from the temperature sensor 20 attached to the thermal head 13 having a plurality of heating elements. are doing. 115a.

Both 115b are memory areas provided in the RAM 115, M115a stores the previous temperature value, and DT1
Temperature information of the thermal head 13 measured this time is temporarily stored in 15b.

A recording unit 102 includes a thermal line head 13 and records an image on recording paper using a thermal recording method. This configuration will be described in detail later with reference to FIG. Reference numeral 20 denotes a temperature sensor attached to the thermal head 13. A signal from this temperature sensor is input to a control unit lot, converted to a digital signal by an A/D converter 18, and input to the CPU 113. Reference numeral 103 is an operation unit including various function instruction keys such as starting transmission, keys for inputting a telephone number, etc., and 104 is usually a
This is a display unit that displays various functions provided in the operation unit 103, the status of the device, and the like. 105 is a power supply unit for supplying power to the entire device. Further, 108 is a modem (modulator/demodulator) that performs AC/DC conversion, 107 is a network control unit (NCU) that controls communication with the line, and 108 is a telephone set.

Next, the configuration of the entire apparatus will be explained in detail with reference to FIG. Note that parts common to FIG. 1 are indicated by the same figure numbers.

In the figure, 10 indicates recording paper 11, which is plain paper, as core 1.
It is a roll paper wound into a roll shape. This roll paper 10 is moved by the rotation of the platen roller 12 in the direction of the arrow, which is rotationally driven by the recording paper conveyance motor.
1 is rotatably housed in the device so that it can supply the thermal head 13 to the thermal head 13. Note that 10b is a roll paper loading section, in which the roll paper 10 is removably loaded. Furthermore, 12 is a platen roller, and the recording paper 1
1 in the direction of the arrow, and the thermal head 1
The recording paper 1 liter is pressed between the heating element 132 of No. 3 and the heating element 132 of No. 3. The recording paper 11 on which an image has been recorded due to the heat generated by the thermal head 13 is conveyed toward the discharge rollers 16a and 16b by further rotation of the platen roller 12, and
When image recording for a page is completed, the cutters 15a and 15b are engaged to cut the image into pages. 21 is a spring,
The thermal head 13 is pressed against the platen roller 12 via the recording paper 11. 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 the figure, 30 is a light source that illuminates the original 32;
The light irradiated from 0 and reflected by the original 32 passes through the optical system (mirrors 50, 51, lens 52) to the CCD sensor 3.
1 and converted into an electrical signal. The document 32 is conveyed in accordance with the reading speed of the document 32 by conveyance rollers 53, 54, 55, 5-6 driven by a document conveyance motor (not shown). Note that 57 is a document loading table, and the plurality of documents 32 stacked on this loading table 57 are separated into one sheet by the cooperation of the conveyance roller 54 and the pressing separation piece 58.
The sheets are separated into sheets and transported to the reading section 100.

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 section.

Further, 106 is a modem board unit that performs communication processing;
07 is an NCU board unit having a relay function with a telephone line.

To explain the operation of the above configuration, when an image signal is input from the modem 106, the control section 101 decodes this image signal, stores it in the line memory 110, and gives an instruction to the recording section 102 to start image recording. The recorded data is stored in the control unit 10.
1 is serially transferred to and stored in the thermal head 13. Next, the control unit 101 uses a motor drive circuit (not shown) to output a phase excitation signal to the recording paper transport motor to move the recording paper 11 in the direction of the arrow. transport in the direction of Thereafter, a strobe signal is output to the thermal head 13, and the heat generating elements 132 of the thermal head 13 are energized block by block to generate heat, thereby performing recording processing for one line.

FIG. 3 is a diagram showing an example of applied pulse width information corresponding to the A/D conversion value of temperature data, which is stored in the table 114a. Here, application pulse width information to the thermal head 13 is stored in correspondence with the output value of the A/D converter 18.

[Description of Recording Process (FIGS. 4 to 6)] FIG. 4 is a flowchart showing the recording process in the facsimile machine of the embodiment, and a control program for executing this process is stored in the ROM1I4 of the control unit 101. . Note that this process is performed after 1 line of image data to be recorded is stored in the line memory 11O. It starts when the recording operation becomes ready to start.

First, in step Sl, record data for one line is serially outputted to the thermal head 13.Next, in step S2, temperature data stored in the memory DT115b is read, and in step S3, the temperature data stored in the memory DT115b is read, and in step S3, the thermal head 13 is outputted with reference to the table 114a. Determine the pulse width applied to In step S4, one block of the heating elements 132 of the thermal head 13 is energized with the pulse width determined in step S3, and in step S5, all the heating elements 13 of the thermal head 13 are energized.
Check whether power is applied to 2.

In step S5, all the heating elements 1 of the thermal head 13 are removed.
32 and the recording of one line is completed, step S
6, the recording paper 11 is conveyed by one line. Next, in step S7, it is checked whether the image recording of one page has been completed. If the image recording of one page has not been completed, the process advances to step S8, and the next line is conveyed. image data is transferred to the thermal head 13. Note that this one line has a length corresponding to the length of one dot recorded by the thermal head 13, and is, for example, 1715.4 mm in the case of a facsimile machine.

When the image recording for one page is completed in step S7, the process proceeds to step S9, and a predetermined amount of the recording paper 11 is transferred to the paper ejection rollers 16a, 1.
6b direction, and the trailing edge of the recording paper on which the image has been recorded is conveyed to the cutting position of the cutter 15. And cutter 15
a and 15b are driven and engaged to cut the recording paper 11 into pages.Next, in step SIO, the cut recording paper is discharged from the apparatus by the discharge roller 16. At the same time, in step Sll, the platen roller 12 is reversed and the recording paper 11 is returned by a distance corresponding to the distance between the thermal head 13 and the cutter 15 so that the leading edge of the platen roller 12 is at the next image recording position. Finish the image recording process.

FIG. 5 is a flowchart showing the temperature detection process in the facsimile machine of the embodiment. This process may be started by an interrupt signal at a predetermined time interval output from a timer (not shown), or step S in FIG.
2. Here, the case of an interrupt will be explained.

When an interrupt occurs, the process advances to step S21, and the temperature information of the thermal head 13 detected by the temperature sensor 20 (
T) is input from the A/D converter on the first day, and step S22
The data is stored in the memory 115a (M). The process waits for a predetermined time to elapse in step S23, and when the predetermined time has elapsed, the process proceeds to step S24, where temperature data (TI) from the A/D converter 18 is input again.

Next, the process advances to step S25, and T l + (T l +
M) to correct the temperature data (TI). here,
M indicates temperature information stored in the memory 115a before a predetermined time has elapsed, and T1 indicates temperature information of the thermal head 13 after a predetermined time has elapsed after the value of M was measured. Then, the temperature information (TI) corrected in step S26 is stored in the memory DT115b.

In this way, by adding the temperature change value (T, -M) of the thermal head 13 after a predetermined time has elapsed after measuring M to the latest temperature information (T1), this corrected temperature information <'r+) is used to determine the width of the pulse applied to the thermal head 13.

FIG. 6 is a diagram showing the relationship between the temperature data of the thermal head 13 and the applied pulse width.

Now, assuming that the temperature detected by the temperature sensor 20 when read in step S21 of FIG. 5 is 40°C,
Temperature information (T=50) is input. After a predetermined period of time has passed, the temperature read in step S24 is 42.
℃, TI="52" is input. As a result, 'T' is corrected to +=52+(52-50)=54 (corresponding to the temperature of the thermal head 13 of 44°C), and the DT
is memorized.

As a result, in step S2 of FIG. 4, this temperature data (T, = 54) is read from the memory DT, and based on this value, in step S3, the applied pulse width of the thermal head 13 is set to "0.36 m5". determined.

In this way, in this embodiment, by determining the pulse width to be applied to the thermal head 13 based on the actual temperature of the thermal head and its temperature change state, it is possible to better correspond to the temperature of the heating element of the actual thermal head. energization control can be performed. In addition, to control the power supply to the thermal head,
In addition to changing the applied pulse width, the applied voltage, applied current, or number of applied pulses may also be changed.

In this embodiment, the temperature change of the thermal head after a predetermined time is detected, but the energy applied to the thermal head may be changed based on the temperature change for each line.

In addition, although this embodiment has been explained in the case of a line-type thermal head, the present invention is not limited to this. For example, even in the case of a serial-type thermal head, temperature changes of the thermal head can be taken into account. The amount of energy applied can be controlled by

As explained above, according to this embodiment, the energy applied to the thermal head is appropriately controlled by correcting the actually detected temperature information of the thermal head according to the temperature change state of the thermal head. It is possible to stabilize the recording density and suppress the extreme temperature rise of the thermal head.

In the above description, the case of a thermal printer using a thermal head was explained, but the present invention is not limited to this. For example, an image can be recorded by causing a heating element to generate heat and ink to fly. Of course, it can also be applied to inkjet recording apparatuses. Among them,
Generating thermal energy in the electrothermal converter by applying heat to the electrothermal converter as a heating element by applying at least one drive signal that causes a rapid temperature rise exceeding nucleate boiling to the electrothermal converter. This causes film boiling on the heat-active surface of the recording head to form bubbles in the ink. Of course, the present invention can also be applied to bubble jet recording devices and the like in which ink is ejected through ejection ports provided in an inkjet head by the growth and contraction of the bubbles. Therefore, the recording head is not limited to a thermal head, but includes, for example, an inkjet head.

[Effects of the Invention] As explained above, according to the present invention, the temperature change state of the thermal recording head is determined by the temperature sensor, and the energy applied to the thermal recording head is controlled based on the temperature change state, thereby recording. This has the effect of stabilizing the density and recording an image on a recording medium.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic configuration of a facsimile machine according to an embodiment, Fig. 2 is a side sectional view showing a mechanical part of a facsimile machine according to an embodiment, and Fig. 3 is an example of a data structure of a table in a facsimile machine according to an embodiment. FIG. 4 is a flowchart showing the recording process in the facsimile machine of the embodiment, FIG. 5 is a flowchart showing the temperature detection process in the facsimile machine of the embodiment, and FIG. 6 shows temperature data and its digital It is a figure which shows an example of the relationship between a value and an applied pulse width. In the figure, 10...rolled recording paper, 11...recording paper,
12...Platen roller, 13...Thermal head, 15...Cutter, 16-...Ejection roller, 18...
・A/D converter, 20... Temperature sensor, 22-... Recording paper presence/absence sensor, 100-... Reading section, 101... Control section, 102... Recording section, 103... Operation section , 10
4--display section, 105--power supply, 106--modem, 107-NCU. 110... Line memory, 111... Encoding/decoding unit, 112... Buffer memory, 113... CP
U. 114...ROM, l'l 4a-" table, 11
5...RAM, 132...Heating resistor (heating element). Figure 3 Figure 6

Claims (4)

[Claims] (1) A recording apparatus that records an image on a recording medium by driving a recording head to generate heat, comprising: a temperature detection means for detecting the temperature of the recording head; and a temperature detected by the temperature detection means after a time. a determining means for determining energy to be applied to the recording head based on a state of change of information; and recording an image on a recording medium by driving the recording head to generate heat based on the applied energy determined by the determining means. A recording device comprising: recording means for recording. (2) The determining means detects a change in temperature of the recording head based on temperature information of the recording head detected after a predetermined period of time, and corrects the temperature of the recording head detected by the temperature detecting means. 2. The recording apparatus according to claim 1, wherein the energy applied to the recording head is determined based on the corrected temperature information. (3) The recording apparatus according to claim 1, wherein the recording head is a thermal head having a plurality of heating elements. (4) The recording head is a bubble inkjet head that forms air bubbles in the ink by heat generation from a heating element, and ejects ink through an ejection port by the growth and contraction of the air bubbles. The recording device according to item 1.