JPH01225570A - Thermal transfer recording apparatus - Google Patents

Abstract

PURPOSE:To realize high printing quality regardless of a printing speed, by counting the accumulated number of the on-dots of the printing data with one page and correcting the driving pulse width of a recording head corresponding thereto and adding this accumulated correction value to the temp. correction value due to a thermistor to adjust energy to be applied. CONSTITUTION:When a converter 37 converts the resistance change to the temp. change of the thermistor 36 mounted to a thermal recording head 1 to voltage and outputs the temp. data 28 of a digital signal, said temp. data 28 is inputted to the address line of an ROM 39. A counter circuit 41 counts the accumulated number of on-dots from the start of the printing of one page to the finish thereof at the start time of printing. When the accumulated dot data 44 outputted from the counter circuit 41 are inputted to the address line of an ROM 42, the ROM 42 outputs timer data 45 due to accumulation correction. This time data 45 is added to the timer data 34 due to the temp. correction outputted from the ROM 39 by ADDER (adder) 43 to be inputted to a timer 33 as composite timer data 46. The timer 33 is loaded with the composite timer data 46 on the basis of a printing trigger signal 32 and turns the STB signal 35 of the recording head 1 ON for a definite time to perform printing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer recording device that performs thermal transfer recording using an ink ribbon coated with multiple colors of ink sequentially.

[Conventional technology]

FIG. 5 is a perspective view of essential parts showing a schematic configuration of a conventional example of this type of thermal transfer recording device.

In the figure, 1 is a recording head equipped with a line-type heating resistor, 2 is a platen roller, and during recording, the recording head 1 is pressed against the platen roller 2 by a spring 5 with the rotation center being a fulcrum 4 attached to a bracket 3. The state is maintained, and the herad motor 6 and cam 7 are activated during standby, etc.
As a result, it separates from the platen roller 2.

Further, a thermistor is provided near the recording head 1 for sensing the temperature of heat emitted from a ceramic substrate constituting a heating resistor of the recording head 1.

Reference numeral 8 denotes a sheet of paper that runs between the recording head 1 and the platen roller 2 from the paper roll 9 in the direction of arrow A; 10, the supply roll 11 and the take-up roll 12 move the recording head 1 and the platen roller 2 together as the paper 8 runs; The ink ribbon runs between the two, and 13 is a pressure roller.

As shown in FIG. 6, the ink ribbon 10 has a width equivalent to the width of the paper 8, and has the dimensions of the recording area 14 of the paper 8 on which transfer inks of the three primary printing colors of yellow, magenta, and cyan are preset. Multiple groups are coated on a dimension L' that is slightly larger than the size L', and marks 15, 1''6, and 17 corresponding to the transfer start position of each color are printed respectively, and can be detected by the sensor 18. ing.

FIG. 7 is a circuit diagram showing the control system of the conventional example.

In the figure, 19 is a control unit composed of ROM, RAM, microprocessor, timer, etc., 20 is an interface line for inputting commands and print data from the outside, 21 is an I10 port for controlling the recording head 1,
22 is a paper feed motor 24 .22 via a motor driver 23 . Ribbon feed morph 25. Control of head motor 6 and paper sensor 26. This is an I10 port for sensing the state of the ribbon sensor 27. These I10 boats 21 and 22 and the control unit 19 are connected by a common control bus 28.

The recording head 1 is driven by CLOCK from I10 port 21.
In synchronization with signal 29, print data is transferred by DATA signal 30.

After the print data has been transferred, a pulse is output to the LATCH signal 31 to latch the data inside the recording head 1.

Next, in order to perform a printing operation, the timer 33 is started by outputting a pulse to the trigger signal 32.
By turning on the STB signal 35 for driving the recording head 1 for a certain period of time according to the timer information 34 input to the recording head 1, the heating resistor of the recording head 1 is heated to perform a printing operation.

The timer information 34 is obtained by converting the change in resistance value with respect to temperature of the thermistor 36 attached to the recording head 1 into a voltage, which is read by the AD converter 37, and furthermore, the temperature information 38 which is the output of the AD converter 37 is sent to the address of the ROM 39. Enter on the line.

The ROM 39 stores timer information for temperature information in advance, and the timer information 34 is outputted to the timer 33 so as to always apply optimal energy in response to temperature changes in the recording head 1.

With the above configuration, for example, yellow and magenta.

When it is determined that the image is to be transferred in the order of cyan, when the power is turned on, the ink ribbon 10 is run by the take-up roll 12, and stopped when the sensor 18 detects the mark 15 corresponding to the transfer start position of yellow. Perform initial settings.

Here, the recording head 1 is pressed against the platen roller 2 by the spring 5 with the fulcrum 4 as the center of rotation, and in this state, the paper 8 and the ink ribbon 10 run simultaneously, and yellow is transferred to the recording area 14 on the paper 8. be exposed.

After the yellow color is transferred, the recording head 1 is moved away from the platen roller 2 by the motor 6 and the cam 7, and the paper 8 is reversely fed by the paper roll 9 to return to the initial position.

Next, the ink ribbon 10 is run with the take-up roll 12 until the sensor 18 detects the mark 16 corresponding to the magenta transfer start position, and the rad 1 is pressed against the platen roller for recording in the same manner as the above-mentioned yellow transfer. The paper 8 and the ink ribbon 10 are run simultaneously to transfer magenta onto the recording area 14 where yellow has been transferred.

After magenta has been transferred, the recording head 1 is moved away from the platen 2 again, the paper 8 is reversed and returned to the initial position, and cyan is transferred in the same manner as above onto the recording area 14 where yellow and magenta have been transferred. Perform transcription and complete recording of one screen.

Then, the ink ribbon 10 is run until the sensor 18 detects the mark 15 corresponding to the next yellow transfer start position, the transfer start position is initialized, and the process waits until the next recording.

During this time, the energy applied to the recording head 1 is adjusted while the thermistor 36 detects the temperature of the heat emitted from the ceramic substrate so that the ink ribbon does not melt due to the heat of the ceramic substrate that constitutes the heating resistor of the recording head 1. .

[Problem to be solved by the invention]

However, in the conventional technology with the above-mentioned configuration, there is a time delay before the thermistor detects the temperature of the heat emitted from the ceramic substrate, so while there was no particular problem during low-speed printing, there was no problem during high-speed printing. This time delay causes the vicinity of the heating resistor to heat up to a temperature higher than that detected by the thermistor, causing the ink ribbon to melt even when no printing is being performed, resulting in a significant deterioration in printing quality.

In view of the above-mentioned problems, the present invention provides a thermal transfer recording device that achieves high printing quality regardless of high speed or low speed by obtaining a configuration that corrects the applied energy in response to actual heating even during high speed printing. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the present invention corrects a temperature difference due to a time delay between a ceramic substrate and a thermistor.

That is, the present invention provides a thermal transfer recording apparatus that has a recording head equipped with a line-type heating resistor and performs thermal transfer recording, including a thermistor that detects the temperature of the recording head, and a thermistor that detects the temperature of the recording head in response to the detected value of the thermistor. a first pulse width correction circuit that calculates a correction value for the drive pulse width; a cumulative on-dot coefficient circuit that cumulatively counts the number of on-dots in print data within one page; and a recorder that corresponds to the coefficient value of the cumulative on-dot coefficient circuit. A second pulse width correction circuit that calculates a correction value for the drive pulse width of the head and an adder that adds the correction values of the first and second pulse width correction circuits are provided, and the composite correction obtained by the adder is provided. It is characterized in that the driving pulse width of the recording head is corrected based on the value.

[For production]

With the above configuration, when the recording head is driven, the present invention cumulatively counts the number of on-dots of print data within one page using the cumulative on-dot coefficient circuit, and the second pulse width correction circuit adjusts the recording head according to this coefficient value. Correct the drive pulse width,
The applied energy can be adjusted by adding this cumulative correction value to the temperature correction value provided by the thermistor.

〔Example〕

Examples will be described below according to the drawings.

FIG. 1 is a circuit diagram showing the configuration of a control system according to an embodiment of the present invention.

The main body of the apparatus is the same as the apparatus described above with reference to FIG. 5, so the explanation will be omitted and the reference numerals will be used as they are.

In the figure, 19 is a control unit consisting of ROM, RAM, microprocessor, timer, etc., 20 is an interface line for inputting commands and print data from the outside, 21 is an I10 port for controlling the recording head l,
22 is a paper feed motor 24 .22 via a motor driver 23 . Ribbon feed motor 25. Control of head motor 6 and paper sensor 26. This is an I10 port for sensing the state of the ribbon sensor 27. These I10 boats 21 and 22 and the control section 19 are connected by a common control bus 29.

The recording head 1 is driven by CLOCK from the I10 boat 21.
In synchronization with signal 29, print data is transferred by DATA signal 30.

After the print data has been transferred, a pulse is output to the LATCH signal 31 to latch the data inside the recording head 1.

37 is an AD converter that converts the resistance change due to temperature change of the thermistor 36 attached to the recording head 1 into voltage and outputs temperature information 38 as a digital signal, and 39 is a ROM in which timer information for temperature information is stored in advance. , temperature information 38 which is the output of the AD converter 37 is input to the address line of this ROM 39.

The configuration up to this point is the same as the conventional one.

Next, 40 is an AND circuit, and by inputting the DATA signal 30 and CLOCK signal 29 output from the I10 port 22, the output of the AND circuit 40 is a clock 0. One pulse is output.

A counter circuit 41 counts the pulses output from the AND circuit 40, and counts the cumulative number of "1"s in the print data width. This counter circuit 41 is reset at the start of printing and counts the cumulative number of on-dots from the start to the end of printing on one page.

42 is a ROM that stores a correction value of the applied pulse width corresponding to the cumulative number of on-dots, 43 is an ADDER (adder), and a counter circuit 41 is connected to the address line of the ROM 42.
The cumulative charge information 44 output from the RO
In response to this, M42 outputs timer information 45 based on cumulative correction. And this timer information 45 is ADDER4
3, it is added to the temperature-corrected timer information 34 output from the ROM 39 and manually input to the timer 33 as composite timer information 46.

The timer 33 outputs ADDER4 by the print trigger signal 32.
The composite timer information 46 sent from 3 is loaded into the timer, and the STB signal 35 of the recording head 1 is turned on for a certain period of time to perform a printing operation.

FIG. 2 is a time chart of the printing operation of this embodiment.

Print data 30 is transferred in synchronization with the CLOCK signal 29, during which time the counter 41 counts the cumulative number of on-dots.

After the print data transfer is completed, the LATCH signal 31 is outputted as one pulse, then the print trigger signal 32 is outputted as one pulse, and the cumulative correction value and the temperature correction value are added.Composite timer information 46 is loaded into the timer 33. , outputs the STB signal 35.

The operation of this embodiment having the above configuration is as follows.

FIG. 3 is a graph showing the temperature rise versus time when the printing duty is 100%. The solid line represents the temperature of the ceramic substrate of the recording head 1, and the dotted line represents the temperature rise when measured by the thermistor 36 for temperature detection. It represents a rise in temperature. Compared to the temperature rise of the ceramic, the thermistor 36 has a time delay due to its heat conduction properties, which deteriorates printing quality.

FIG. 4 is a graph showing the case where cumulative correction is added to temperature correction.

In the figure, the solid line is the cumulative number of on-dots when the printing duty is -100%, the dotted line is during the pulse of the STB signal 35 when temperature is corrected only by the thermistor 36, and the -dotted line is the addition of the cumulative correction -Δm to the temperature correction by the thermistor 36. ST did
This is during the pulse of the B signal 35.

As described above, the deterioration in printing quality due to the temperature difference between the ceramic substrate and thermistor 36 in FIG. 3 is corrected to some extent by the cumulative correction Δt shown in FIG. 4.

〔Effect of the invention〕

As described in detail above, according to the present invention, in a thermal transfer recording apparatus that performs thermal transfer recording and has a recording head equipped with a line-type heating resistor, a thermistor that detects the temperature of the recording head; a first pulse width correction circuit that calculates a correction value for the driving pulse width of the recording head in response to the detected value; a cumulative on-dot coefficient circuit that cumulatively counts the number of on-dots of print data within one page; a second pulse width correction circuit that calculates a correction value for the drive pulse width of the recording head in accordance with the coefficient value of the circuit; and an adder that adds the correction values of the first and second pulse width correction circuits. The driving pulse width of the recording head is corrected by the composite correction value obtained by the adder.
It is possible to correct the temperature difference due to time delay between the ceramic substrate and the thermistor.

This makes it possible to immediately correct the applied energy in response to actual heating even during high-speed printing.
This has the effect of providing a thermal transfer recording device that achieves high print quality regardless of low speed.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a control system according to an embodiment of the present invention, and FIG. 2 is a time chart showing the printing operation of the embodiment.
Fig. 3 is a graph showing the temperature rise versus time when the printing duty is 100%, Fig. 4 is a graph showing the case where cumulative correction is added to temperature correction, Fig. 5 is a perspective view of the main part of the conventional example, and Fig. 6 The figure is a plan view showing an ink ribbon used in the conventional example, and FIG. 7 is a circuit diagram showing the configuration of the control system of the conventional example. 34...Timer information 36...Thermistor 37...AD converter 39...ROM 40...AND circuit 41...Counter circuit 42...ROM 43...ADDER 45...Timer information 46... Composite timer information patent Applicant: Oki Electric Industry Co., Ltd. Agent: Patent attorney Plane 1 showing the conventional ink ribbon of Takakura Kanakura Export: 6 Countries

Claims (1)

[Scope of Claims] 1. In a thermal transfer recording device that has a recording head equipped with a line-type heating resistor and performs thermal transfer recording, a thermistor that detects the temperature of the recording head and a sensor that corresponds to the detected value of the thermistor are provided. A first pulse width correction circuit that calculates a correction value for the driving pulse width of the recording head; a cumulative on-dot coefficient circuit that cumulatively counts the number of on-dots of print data within one page; and a coefficient value of the cumulative on-dot coefficient circuit. a second pulse width correction circuit that calculates a correction value for the drive pulse width of the recording head in response to the above, and an adder that adds the correction values of the first and second pulse width correction circuits; 1. A thermal transfer recording apparatus, characterized in that a driving pulse width of a recording head is corrected using a composite correction value obtained in .