JPH06238937A - Recorder - Google Patents

Abstract

PURPOSE:To carry out printing at high speed when a temperature of a thermal head is high by a method wherein a time width of a pulse voltage specifying electrification time of a thermal head is selected according to the temperature of the thermal head, an<d besides a recording cycle in a case where a character data is recorded per line is set based on the selected electrification time. CONSTITUTION:Temperatures of thermal heads 3a-3c are detected with a temperature sensor 7. Then, a CPU 1 selects a time width of a pulse voltage specifying electrification time of the thermal head, when the temperatures of the thermal heads 3a-3c are detected, according to the detected temperature to set a recording cycle in a case where a character line is recorded per each line based on the selected electrification time. Consequently, the recording cycle can be determined according to the temperature of the thermal head. For example, the recording cycle and the electrification time of the thermal head can be shortened at high temperature, and therefore printing can be carried out at high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for conducting heat-sensitive recording by energizing a plurality of heating resistors constituting a thermal head.

[0002]

2. Description of the Related Art Conventionally, a recording apparatus of this type has a plurality of thermal heads each composed of a plurality of heating resistors that generate heat when energized, and a motor for moving these thermal heads. While moving to a predetermined recording position and energizing each thermal head, a plurality of heat generating resistors in each thermal head are caused to generate heat, and character data is recorded by this heat generation. That is, when character data is input from the host device, the motor is driven to move each thermal head to a recording position on a predetermined line, and then a pulse voltage corresponding to the character data is sequentially and selectively applied to each thermal head. Energize each heating resistor in each thermal head. As a result,
Each of these heating resistors generates heat, and thermal recording is performed on the recording paper.

FIG. 5 is a timing chart showing the recording operation of the recording apparatus. FIG. 5A is a drive pulse for driving a motor, and FIGS. 5B to 5D are thermal heads A to C. The applied pulse applied to is shown. That is, the motor is driven at a timing shown in FIG. 5A to move each thermal head to a predetermined recording position, and when the movement is completed, the thermal head A, the thermal head B, and the thermal head C are sequentially and selectively pulsed. Is applied to each thermal head to record electricity. When the character recording is completed, a drive pulse is given to the motor to move the thermal head to the recording position of the next line, and similarly, energization according to the character data is performed. In the figure, t is referred to as a recording cycle, which indicates a cycle when the character data is recorded line by line, and the recording cycle is a constant value of 10 msec, for example.

[0004]

Generally, when the temperature of the thermal head is high, the print head reaches a prescribed printable temperature in a short energization time, and therefore, as shown in FIGS. 5 (e) to 5 (g), a short time is required. Characters can be recorded by applying the pulse voltage of. However, in the conventional recording apparatus, since the recording cycle t of character data is constant, even if the pulse voltage of a short time is applied to the thermal head for recording, the character of the next line should be recorded. There is a problem in that the head does not move to the position and therefore a wasteful time t ′ as shown in FIG.

Therefore, an object of the present invention is to print characters at high speed when the temperature of the thermal head is high.

[0006]

In order to solve such a problem, the present invention is directed to a temperature sensor for detecting the temperature of a thermal head and a time of a pulse voltage applied to the thermal head and defining a conduction time of the thermal head. An energizing time selecting means for selecting the width according to the output of the temperature sensor, and a recording cycle setting means for setting a recording cycle for recording the character data line by line based on the selected energizing time are provided. Is.

[0007]

When the temperature of the thermal head is detected, the time width of the pulse voltage that defines the energization time of the thermal head is selected according to the detected temperature, and one line of character data is selected based on the selected energization time. A recording cycle is set for each recording. As a result, the recording cycle is determined according to the temperature of the thermal head. For example, when the temperature is high, the recording cycle and the energization time of the thermal head can be shortened, and therefore printing can be performed at high speed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a recording apparatus according to the present invention. In the figure, 1 is a CPU for controlling the entire recording apparatus, 2 is a memory for storing various data, 3a to 3c are thermal heads each composed of a plurality of heating resistors, and 4a to 4c are thermal heads. A driver for supplying an energizing current to the heating resistor therein, 5 is a motor for moving each thermal head to a predetermined recording position, 6 is a driver for driving the motor 5, and 7 is a temperature of each thermal head. It is a temperature sensor.

When the CPU 1 of this recording device receives character data to be printed on each thermal head from a host device (not shown), it applies a drive pulse to the motor 5 via the driver 6 to drive the motor 5 to drive each thermal head. 3a ~
3c is conveyed to a recording position on a predetermined line. Then, the pulse voltage corresponding to the input character data is applied to each driver 4a.
To 4c are sequentially and selectively applied to the thermal heads 3a to 3c.
Each character is recorded by the heat generation of each heating resistor of c, and when this is completed, the motor 5 is driven to convey the thermal head to the recording position of the next line and the next received character is similarly printed and recorded. . Here, the application time of the pulse voltage applied to each thermal head is determined according to the temperature value of the thermal head detected by the temperature sensor 7, and each character is recorded line by line, as described later. Similarly, the recording cycle in the case of being determined is also determined by the detection value of the temperature sensor 7, and therefore the recording speed (printing speed) of the thermal head is determined according to the temperature.

FIG. 2 is a CP for performing the above recording control.
3 is a timing chart showing the operation of U1, CPU1
7A to 7C show the output timings of the drive pulse for the motor 5 and the applied pulses for the thermal heads 3a to 3c. Here, (a) to (d) in the figure show the output timing of each pulse when each thermal head is in a low temperature state, and (e) to (h) show each pulse when each thermal head is in a high temperature state. This is the output timing. It should be noted that t1 and t2 indicate the above-described recording cycle at low temperature and high temperature, respectively.

Such recording periods t1 and t2 are shown in FIG.
It can be obtained from a table which shows the correlation between the temperature of the thermal head stored in advance in the memory 2 and the recording pulse width of the thermal head at that time as shown in FIG. In the figure, a, b, and c are recording cycle curves showing recording cycles for respective temperatures of the thermal head, and the recording cycles are 10 msec, 7.5 msec, and 5 msec, respectively.
Is shown. Here, in FIG. 4, when the printable pulse width for the thermal head at the temperature T1 is P1 and P2 from the longest order, the recording pulse width P2 having the shortest pulse width is selected (energization time selection means). At the same time, the recording cycle curve b passing through the intersection of the straight line (dotted line) indicating the recording pulse width P2 and the straight line (dotted line) indicating the temperature T1 selected at this time is selected. Therefore, in this case, the recording cycle of 7.5 msec Selected (recording cycle setting means). Further, when the pulse width that can be printed on the thermal head at the temperature T2 is P1 ', P2', P3 'from the longest order,
The recording pulse width P3 'having the shortest pulse width is selected, and the recording period curve c passing through the intersection of the straight line showing the selected recording pulse width P3' and the straight line showing the temperature T2 is selected. In this case, a recording cycle of 5 msec is selected.

In the recording cycle thus selected, each character is 1
The lines are printed and recorded. When actually printing with a thermal head, the recording pulse width P2 is selected at the temperature T1 and the recording pulse width P3 'is selected at the temperature T2 as the pulse width that defines the energization time. .

Next, FIG. 3 is a flow chart showing the operation of the CPU 1 when recording is performed by controlling the thermal head. The detailed control operation of the CPU 1 will be described based on this flowchart. That is, the CPU 1 first detects the temperature T of the thermal head via the temperature sensor 7 in step ST1 when the thermal head is energized for thermal recording. Then, it is determined in steps ST2 to ST4 what value the detected temperature has.

The detected temperature T is -10 ° C to 0 ° C.
When it is determined to be “Y” in step ST2, 10 msec is selected as the recording cycle from the table of the memory 2 in step ST5. Further, when the detected temperature T is in the range of 0 ° C to 35 ° C and it is determined to be "Y" in step ST3, 7.5 msec is similarly selected from the table as the recording cycle in step ST6. Further, when the detected temperature T is in the range of 35 ° C to 65 ° C, the step ST
When it is determined to be "Y" in step 4, 5 msec is similarly selected from the table as the recording cycle in step ST7.

When the recording cycle corresponding to the temperature of the thermal head is selected in this manner, the CPU 1 then proceeds to step ST8.
Select the recording pulse width that specifies the energization time of the thermal head with. Regarding the selection of the recording pulse width, as described above, it is selected when the shortest recording cycle is selected according to each detected temperature, and therefore the shortest pulse width is selected. In step ST9, each thermal head is energized by the shortest recording pulse selected while driving the motor 5 in the recording cycle thus selected, and recording is performed line by line. Then, in step ST10, it is determined whether the recording of one page has ended, and if it is determined to be "Y", the recording ends, and if the recording of one page does not end, step ST
Return to step 8 to record the next line.

[0016]

As described above, according to the present invention,
The time width of the pulse voltage that defines the energization time of the thermal head is selected according to the temperature of the thermal head, and the recording cycle for recording character data for each line based on the selected energization time is set. Therefore, for example, when the temperature of the thermal head is high, the recording cycle and the energization time to the thermal head can be shortened, so that high-speed printing can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a recording apparatus according to the present invention.

FIG. 2 is a timing chart showing a recording operation of the above apparatus.

FIG. 3 is a flowchart showing the operation of the above apparatus.

FIG. 4 is a diagram showing a selection situation of an energization time to a thermal head and a recording cycle in the above apparatus.

FIG. 5 is a timing chart of a conventional recording apparatus.

[Explanation of reference numerals] 1 CPU 2 memories 3a to 3c thermal heads 4a to 4c, 6 driver 5 motor 7 temperature sensor

Claims (1)

[Claims] 1. A plurality of thermal heads each composed of a plurality of heating resistors that generate heat when energized, a motor that moves these thermal heads, and a pulse voltage is sequentially and selectively applied to each thermal head. A pulse voltage applying means for energizing, when the character data is received, the motor is driven to move each thermal head to a predetermined recording position, and the pulse voltage applying means is controlled to apply the pulse voltage to each thermal head. In a recording device that performs recording for one line by giving a recording line and recording for the next line after a predetermined recording period, a temperature sensor that detects the temperature of each thermal head,
Energization time selection means for selecting a time width of the pulse voltage that defines the energization time of the thermal head according to the output of the temperature sensor, and recording cycle setting means for setting the recording cycle based on the selected energization time. A recording apparatus comprising: