JPH0569581A - Printer - Google Patents

Abstract

PURPOSE:To always obtain a constant real printing length without a variation per unit and a change with time. CONSTITUTION:A period of a drive pulse P of a stepping motor for driving a platen and a period of a strobe signal S' are independently controlled. The period of the strobe signal S' is arbitrarily variably set by a presetting device 11 at any time. In this manner, a real printing length can be easily adjusted to be constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal type printer which makes a real print length constant.

[0002]

2. Description of the Related Art The structure of a conventional example will be described with reference to FIG. FIG. 4 is a block diagram showing a conventional printer.

In FIG. 4, reference numeral 1 is a printer controller, and 2 is a printer controller.
Is a CPU such as a so-called microcomputer, 3 is R
OM, 4 is RAM, 5 is a strobe signal control circuit, 6 is a pulse control circuit, 7 is a thermal head connected to the strobe signal control circuit 5, 8 is a step motor connected to the pulse control circuit 6, and 9 is a step motor. A platen that is driven to rotate by 8 to convey the sheet 10. Also,
S represents a strobe signal output from the strobe signal control circuit 5, and P represents a drive pulse output from the pulse control circuit 6.

Next, the operation of the above-mentioned conventional example will be described with reference to FIG. FIG. 5 is a timing chart showing the operation of the conventional printer. In FIG. 5, (a) shows the drive pulse P and (b) shows the strobe signal S, respectively. The cycle of the drive pulse P is t ₁ , and the cycle of the strobe signal is t ₂ (= t ₁ ).

Under the control of the CPU 2 in the printer controller 1, the step motor 8 is driven by the drive pulse P output from the pulse control circuit 6, and the platen 9 rotates to convey the paper 10 in a predetermined direction. Further, the thermal head 7 is driven by the strobe signal S output from the strobe signal control circuit 5 in synchronization with the drive pulse P, and a predetermined image is printed on the paper 10.

[0006]

However, the conventional printer as described above has a problem that the actual print length is different due to the variation of the platen diameter between the solids. In addition, there is a problem in that the actual print length changes due to the aging (decreasing) of the platen diameter.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to obtain a printer capable of adjusting the actual print length to a constant value.

[0008]

A printer according to the present invention comprises the following means. [1] A preset setting device that sets a predetermined value corresponding to the cycle of the strobe signal of the thermal head. [2] A reference pulse generator that generates a reference pulse. [3] A preset counter that generates a pulse when the reference pulse is counted by the predetermined value. [4] A control unit that drives the thermal head with the strobe signal based on the pulse and drives a step motor that rotates the platen independently of the strobe signal at a constant cycle.

[0009]

According to the present invention, the preset setting device sets a predetermined value corresponding to the cycle of the strobe signal of the thermal head. A reference pulse is generated by the reference pulse generator. Further, the preset counter generates a pulse when the reference pulse is counted by the predetermined value. Then, the thermal head is driven by the strobe signal based on the pulse by the control means, and the step motor that rotates the platen independently of the strobe signal is driven at a constant cycle.

[0010]

【Example】

Example 1. The configuration of the first embodiment of the present invention will be described with reference to FIG. 1 is a block diagram showing a first embodiment of the present invention, in which the CPU 2 to the paper 10 are exactly the same as those of the above-mentioned conventional apparatus. However, the thermal head 7 to the paper 10 are not shown. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1A is a printer control device,
11 is a non-volatile preset setting device, 12 is, for example, several M
Reference pulse generator that generates a reference pulse of about 1 Hz, 1
Reference numeral 3 is a down counter preset counter.

By the way, the control means of the present invention comprises the CPU 2, the strobe signal control circuit 5 and the pulse control circuit 6 in the first embodiment of the present invention described above.

Next, the operation of the above-described first embodiment will be described with reference to FIGS. 2 and 3. 2 and 3 are timing charts showing the operation of the first embodiment of the present invention.

In FIG. 2, (a) shows the operation of the preset counter 13, (b) shows the outputs B ₁ , B ₂ of the preset counter 13, and (c) shows the reference pulse C which is the output of the reference pulse generator 12. Indicates.

The user sets a preset value A ₁ or A ₂ (for example, 2 in order to adjust the actual print length by the preset setting device 11).
Shows the street. ) Is set. Reference pulse generator 12
Generates a reference pulse having a constant frequency and supplies it to the preset counter 13. This preset counter 13
The reference pulse C is down-counted from the set value A ₁ or A _2, and when it becomes 0, the output B ₁ or B ₂ is supplied to the CPU ₂ .

Here, the set value A is determined as follows.
That is, the actual print length when printing at t ₂ = t ₁ is L ₂ ,
If the standard print length (calculated print length when there is no variable element) is L ₁ , then t ₂ '= (L ₁ / L ₂ ) · t ₁ (ms
The set value A is determined so as to be ec).

The setting timing is set when the user notices that the actual print length has deviated or at regular intervals.

In FIG. 3, (a) shows the drive pulse P output from the pulse control circuit 6, and (b) shows the strobe signal S'output from the strobe signal control circuit 5, respectively.

Under the control of the CPU 2 in the printer controller 1A, the step motor 8 is driven by the drive pulse P output from the pulse control circuit 6, and the platen 9 rotates to convey the paper 10 in a predetermined direction.

On the other hand, the CPU ₂ changes the cycle of the strobe signal S'to t ₂ 'based on the output B ₁ or B ₂ from the preset counter 13 as shown in FIG. The thermal head 7 is driven by the strobe signal S ′ output from the sheet, and a predetermined image is printed on the sheet 10.

The first embodiment of the present invention, as described above,
Since the drive pulse P for driving the step motor 8 and the strobe signal S ′ for printing are controlled independently of each other, the cycle of the strobe signal S ′ can be variably set so as to keep the actual printing length constant. This has the effect of enabling accurate management of the actual print length.

That is, for the purpose of always obtaining a constant length by eliminating the variation of the actual print length between individuals and the secular change, the cycle control of the drive pulse P of the step motor 8 for driving the platen 9 and the strobe signal S are performed. It is possible to easily adjust the actual print length to a constant value by independently setting the cycle control of the ', and by variably setting the cycle of the strobe signal S'by the preset setting device 11 at any time.

[0023]

As described above, according to the present invention, a preset setter for setting a predetermined value corresponding to the cycle of the strobe signal of the thermal head, a reference pulse generator for generating a reference pulse, and the reference pulse for A preset counter that generates a pulse when counting a predetermined value and a step motor that drives the thermal head with the strobe signal based on the pulse and that rotates the platen independently of the strobe signal at a constant cycle Since it is provided with the control means for controlling, the actual print length can be adjusted to be constant.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the first embodiment of the present invention.

FIG. 3 is a timing chart showing the operation of the first embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional printer.

FIG. 5 is a timing chart showing the operation of a conventional printer.

[Explanation of symbols]

 1A Printer control device 2 CPU 5 Strobe signal control circuit 6 Pulse control circuit 11 Preset setting device 12 Reference pulse generator 13 Preset counter

Claims (1)

[Claims] 1. A preset setter for setting a predetermined value corresponding to a cycle of a strobe signal of a thermal head, a reference pulse generator for generating a reference pulse, and a pulse when the reference pulse is counted by the predetermined value. A preset counter; and a control means for driving the thermal head with the strobe signal based on the pulse and for driving a step motor for rotating the platen independently of the strobe signal at a constant cycle. Printer.