JPS606483A - Thermal printer head - Google Patents

Abstract

PURPOSE:To make it possible to set power to be supplied to a target value in mounting and to always obtain optimum density, in a thermal printer head containing large number of heat generating resistors, by providing a means for outputting average resistance value information. CONSTITUTION:When a thermal printer head is connected to a main body, information output terminals 14A-14D and an earth terminal 16 are connected to the corresponding inputs of a supply power control circuit 18. Because binary signals representing the average resistance values of heat generating resistors are generated in the terminals 14A-14D, these signals are used as address signals and a supply power value such as voltage to be applied or a current supply time is read from memory to set voltage to be applied or the current supply time by the supply power control circuit 18. By this method, mounting and adjustment in preparing and assembling a thermal printer head and work in maintenance and exchange can be rapidly performed and optimum density can be always obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a thermal printhead, and more particularly to a thermal printhead provided with an average resistance value output terminal.

(Prior Art) As is well known, a thermal print head consists of a large number of heating resistor elements.

Current is selectively supplied to each heating resistor element to generate heat, thereby performing thermosensitive recording.

In this case, the recording density depends on the heating temperature of the heating resistor element, and the heating temperature is determined by the resistance value of each heating resistor element and the applied voltage. Therefore, in order to obtain recording with uniform density, it is necessary to make the resistance values of the individual heating resistor elements uniform. However, in reality, it is impossible to make the resistance values of the individual heating resistor elements completely uniform.

At present, the average resistance value of thermal printheads sold by general manufacturers generally varies by about ±10% with respect to the standard or target average resistance value. For example, set the standard or target average resistance value to 5000
Then, the average resistance value will be distributed in the range of 450 to 550Ω.

With conventional heating resistor elements, only the average resistance value of the heating resistor elements included in each thermal print head is displayed.

Therefore, in order to record at the desired density using this thermal print head, the voltage applied to the thermal print head and the thermal It is necessary to set the time for energizing the print head, etc., and this work is quite complicated and takes a long time.

In addition, due to disconnection or short circuit accidents of the heating resistor element,
Even when the thermal print head is replaced, the settings for the voltage and energization time must be readjusted, which has the disadvantage that maintenance and replacement work requires hot wires and a long time.

(Purpose) The present invention was made in order to eliminate the above-mentioned drawbacks, and its purpose is to automatically control the voltage applied to the thermal print head and the energization time to the thermal print head. To provide a thermal print head that can be set without any trouble.

(Overview) In order to achieve the above object, the present invention provides a thermal print head with a terminal or a cord capable of outputting the average resistance value of the heating resistor elements included therein as electrical information. There is a percentage mark at the point where the board was installed.

(Example) The present invention will be described in detail below with reference to the drawings. FIG. 1 is a plan view showing a schematic configuration of an embodiment of the present invention, and FIG.
The figure is a circuit diagram showing the electrical connection relationship of each information output terminal in the electrical connection connector.

As shown in FIG. 1, a thermal printhead 10 is provided with a connector 12 for electrical connection. In the electrical connection connector 12, information output terminals 14A to 14D (generally, at least one output terminal is sufficient) and a ground terminal 16 are provided.

Then, each information output terminal +4A to 14D and the ground terminal 16
grounded or ungrounded (
open) state.

For example, as mentioned above, suppose that the average resistance value of the heating resistor element is distributed in the range of 450Ω to 550Ω, and when classifying this into 4 classes, the connection status between each information output terminal and the ground is , as shown in Table 1.

As is clear, when "connected", the potential of the corresponding information output terminal is the ground potential, and on the other hand, when "open", it is a non-ground potential (positive or negative constant value is about 1) Therefore, by assigning binary numbers 1 and 0 to these, they can be easily processed digitally.

As is clear from the above description, when there are two information output terminals, the pressure can be classified into four classes based on the average resistance value of the heating resistor element. In addition, if the number of information output terminals is increased to 3, 4, etc., which can be easily expressed in the first representation, 8 classes and 16 classes, respectively, can be handled more precisely, and more precise power supply can be achieved. (applied voltage or energization time) can be adjusted.

When the thermal print head shown in FIG. 1 is connected to the main body of the thermal recording device, the information output terminals +4A to +4D
and ground terminal 16 are connected to respective corresponding inputs of power supply control circuit 18, as shown in FIG.

As mentioned above, two communication signals representing the average resistance value of the heating resistor element are generated at the information output terminals 14A to 14D, so these are taken into the power supply control circuit 18 and controlled by the power supply control circuit 18. 4 for controlling the power (applied voltage or energization time) supplied to each heating resistor element to the signal output terminal 20;
It is extremely easy for a person skilled in the art to output No. 6.

For example, the supply power control circuit 108 is connected to the information output terminal +4A
Let the memory be addressed by a binary input of ~+40,
If you memorize the scheduled values (applied voltage or energization time) in each corresponding address, you can configure settings without any trouble or judgment just by connecting the thermal print head to the thermal recording device main body. The applied voltage or energization time can be set such that the recording density can be obtained.

Alternatively, if you turn the switch on and off and select the voltage divider circuit or time constant circuit using the grounded/ungrounded signals applied to the information output terminals +4A to +4D, the same power supply will be obtained. It is clear that adjustments or settings can be made.

In the above embodiment, a case has been described in which the average resistance value information is output as binary information of grounding and non-grounding levels, but it is well known that any method that can extract binary information can be used.

Also, K instead of the information output terminal and ground terminal.

A code plate having concave and convex portions corresponding to each is provided, and for example, the concave portions correspond to the binary number 101, and the convex portions correspond to the binary number 11'.
It is also possible to set K to correspond to .

Moreover, although an example has been described above in which the supplied power is controlled to the set value by adjusting either the applied voltage or the energization time, it is clear that both may be adjusted.

(Effects) As is clear from the above description, according to the present invention, the following effects are achieved.

By simply connecting or attaching the thermal print head to the main body of the thermal recording device, you can supply power to the thermal print head (with less applied voltage or energizing time) without any trouble or interruption. Since it is possible to set a target value for the thermal print head, it is possible to carry out installation, adjustment, or maintenance and replacement work extremely quickly during manufacturing and assembly of the thermal print head, and to always set the optimal density. .

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of an embodiment of the present invention, and FIG. 2 is a schematic plan view of an embodiment of the present invention.
It is a circuit diagram showing section A. 10... Thermal print head, 12... Electrical connection connector, +4A-+4D... Information output terminal,
16...Grounding terminal, 18...Supply 'torque force control circuit'
20... Control signal output terminal representative patent attorney Michi Hiraki 1 non-person 1 Figure 2 days

Claims (3)

[Claims] (1) A thermal print head comprising a large number of heating resistor elements, and characterized in that it is provided with means for outputting average resistance value information. (2) The average resistance value information output means is at least one information output terminal, and the grounded/ungrounded state of the information output terminal is a binary number of °01. 1. The thermal print head described in Patent No. 1, characterized in that it is compatible with J+. (3) The average resistance value information output means is a code plate having concave and convex portions, and the concave portions and convex portions each have a binary IQ value.
, 11-.