JPS59127779A - Thermal recording head - Google Patents

Abstract

PURPOSE:To contrive to make uniform printing quality, by a method wherein row-direction electrodes for heating elements arranged in a matrix form on a rotary drum and a driving power source are brought into sliding contact with each other. CONSTITUTION:The heating elements arranged in a matrix form are constituted of upper electrodes 6 and lower electrodes 4 which are provided on the rotary drum 2 and are selected on a column basis in accordance with information. The electrodes 4 are connected to the driving power source on a row basis through sliding contact of terminals 8 with ring form electrodes 23 provided on the side of a fixed slide plate 22, and thermal dot printing is conducted on a recording paper 30. Accordingly, effects of variation in frictional contact and defects in the heating elements are reduced, as compared to the case of pressing only one column of heating elements against the recording paper, and it can be contrived to make uniform the printing quality.

Description

Detailed Description of the Invention (a) Technical field The present invention aims to uniform print quality by avoiding frictional contact with recording paper such as thermal paper, and reducing the influence of malfunctions due to defects in heating elements. , relates to a thermal recording head that can drive heating elements with a simple configuration.

(B) Prior Art As a conventional thermal recording head, for example, there is one in which an electric resistor is provided on a ceramic, and a plurality of heating elements, each of which is covered with a wear-resistant layer, are arranged in a row.

In the above configuration, heat is generated by applying a voltage to the resistor in accordance with a recording signal converted into 9 parallels by a shift register, and the recording paper such as thermal paper that is in contact with the resistor through the wear-resistant layer is heated. Prints according to the information.

However, according to conventional thermal recording heads, since the recording paper such as thermal paper is brought into contact with the heating element by a suppression roller, the thickness of the wear-resistant layer may vary due to friction.
There is a risk that frictional debris from the recording paper will adhere and deteriorate the quality of the printed product, and since the heating elements are arranged in a line in the main scanning direction, malfunction due to even a single bit defect may cause damage to thermal paper, etc. There is a risk that black or white spots may appear in the feeding direction of the recording paper, reducing print quality.

OBJECT AND CONSTRUCTION OF THE INVENTION The present invention was made in view of the monarchy, and it is an object of the present invention to avoid frictional contact with recording paper such as thermal paper, and to reduce the number of malfunctions due to defects in heating elements, thereby improving print quality. In order to achieve uniformity and to be able to drive the heating elements with a simple configuration, a plurality of electrodes in the row and column directions are arranged on the rotating drum at intervals corresponding to a predetermined dot density in a matrix pattern. The present invention provides a thermal recording head in which a heating portion is formed, one drive voltage is applied to one row direction electrode by sliding contact, and the column direction electrodes are driven in accordance with information.

) Example (configuration) The thermal recording head of the present invention will be explained in detail below.

FIG. 1 shows the entire system according to the present invention, including a rotating drum-type thermal recording head 1, a drive circuit 20 that drives the rotating drum-type recording head 1 according to information, and a drive roll that guides thermal paper 30 in the recording direction. 40, a cutter 50 for cutting the printed thermal paper 30 into a predetermined size, and a cutter receiver 60.

FIGS. 2(a) and 2(b) show a rotating drum type thermal recording head 1, in which the surface of the drum base 2 of At203 is uniformly coated with an under glass 3, and a lower electrode 4 extending in the row direction is formed on the under glass 3. A predetermined number of them are provided in parallel with a predetermined interval. A resistor 5 is provided on the lower electrode 4, and a predetermined number of upper electrodes 6 extending in the column direction are provided in parallel on the resistor 5 at predetermined intervals. Under glass 3 is At
A film with a thickness of 20 to 60 μm is formed on the surface of the drum base 2 of No. 203 by screen printing or the like, and the lower 1tll is formed.
l The N-electrode 4 has 0.0% chromium on the under glass 3. I
Furthermore, gold is uniformly deposited thereon by 0.2μ electron beam evaporation, etc., and then photoetched to obtain a predetermined dot density. Turn and form. In addition, the resistor 5 is made of, for example, a semiconductor such as 81, and has a volume resistivity ρ of 50 to 500 and approximately Ω·100.
The upper electrode 6 is formed by uniformly depositing it by 0.5μ electron beam evaporation or the like, and then turning it by photoetching so that it has a constant dot density.

In addition, as another example, as the lower mold @ 4, Envirhart's Nometaloriganix gold (A-2515) was printed in a predetermined number (turn) by screen printing and dried.
After firing the resistor 5, RuO2 may be printed on the entire surface to a thickness of 20 μm, dried, and fired.

FIG. 3(a) shows a heat-generating section (the resistor 5 held between the upper and lower electrodes 4 and 6 mentioned above) in the row direction that contacts the thermal paper 3o guided in the recording direction by the drive roll 4o in response to information. An example is shown in which the upper electrode 6 is driven by one drive circuit 20 to generate heat, and a drive signal output from the drive circuit 20 is supplied to the upper electrode 6 via the sliding piece 21. FIG. 3(b) shows a selector 20a that applies 1 drive voltage V to the lower electrode 4 corresponding to the heat generating part in the row direction that contacts the thermal paper 30, A fixed sliding plate 2 is formed with a sliding terminal 8 connected to the electrode 4 via a lead 7, and faces the end face.
2 is provided. The fixed sliding plate 22 has a number of concentric ring electrodes 23 corresponding to the number of lower electrodes 4, and each ring electrode 23 is in electrical contact with a corresponding sliding terminal 8 at a different position in the radial direction. , a driving voltage V is applied to the lower electrode 4 via the switch 24 of the selector 20a.

FIG. 4 electrically shows the relationship between the heat generating portion formed by the upper and lower electrodes 4 and 6 and the resistor 5, the drive circuit 20, and the selector 20a. The lower electrode 4 extending in the row direction is the selector 2
The upper electrode 6, which is connected to the drive power supply V through 0a and extends in the column direction, is connected to the drive 1-b circuit 20 through a sliding piece 21. The drive circuit 20 outputs a recording signal (serial) to -
It is connected to shift registers 25 and 26 which accumulate the data for each line and output it as a parallel signal. Note that the shift registers 25 and 26 have terminals r, 1, and L for inputting recording signals.
The selector 20a has a terminal CL which inputs a clock signal and sequentially turns on the switch 24 (FIG. 3(b)).

(E) Example (Operation) In the above configuration, the operation will be explained with reference to the time chart shown in figure arr5. When the printing operation starts, the drive roll 40 guides the thermal paper 30, and at the same time the rotating drum type The thermal recording head 1 starts driving. When the thermal recording head 1 starts driving, the lower electrode 4 corresponding to the heat-generating part that contacts the thermal paper 30 and prints is activated by the corresponding switch based on the clock pulse CL1. 24 receives the driving voltage V (via the ring electrode 23, the sliding terminal 8 and the lead 7).Meanwhile, the shift registers 25 and 26 receive recording signals from the terminals L1, I, 2 and store them. The shift register 25 outputs a high, 1OVR bit signal (parallel) according to the information to the drive circuit 20 that drives the upper electrodes 6 arranged in the column direction by the control signal S1, and the shift register 26 outputs the control signal S2.
outputs similar bit signals (parallel).

The drive circuit 20 drives the upper electrode 6 via the sliding piece 21 based on the bit signal, and connects the driven upper electrode 6 to the resistor of the portion that receives the drive voltage V and is held by the lower electrode 4. The body 5 generates heat and prints on the thermal paper 30. When the thermal recording head 1 rotates at a circumferential speed depending on the dot density between lines and the guiding speed of the thermal paper 30, the lower electrode 4 corresponding to the heat-generating part that will next contact the thermal paper 30 and print will be connected to the next clock. Pulse C
The drive #I is turned on by turning on the corresponding switch 24 based on L2.
In the same way, the drive circuit 20 and the sliding piece 2
1, and thereafter the clock pulse CL
5° CL4...Continues printing operation.

Incidentally, if the diameter of the rotating drum type thermal recording head 1 is set based on the longitudinal width (298 mm) of A4 size paper, then if n=5 is selected, n=19+nm can be obtained.

(v) Other Embodiments Figure 6 (a), ←) shows a second embodiment of the drive voltage supply section which selects the electrodes (lower box; poles) 4 in the row direction and applies the drive voltage V. , the lower electrode 4 of the rotating drum type thermal recording head 1
A sliding terminal 8 is connected to the IJ-door through the door, and the sliding terminal 8 of the electrode 4 in the row direction contacts the recording paper 30 to print.
A fixed electrode 27 for the box and source is provided at a position in contact with the box and source.

In the above configuration, when the recording paper 30 is advanced by the drive roll 40 and the gutter 1 rotates for thermal recording, the sliding terminal is moved from the fixed electrode 27 to the electrode 4 in the row direction that contacts the recording paper 1 and prints. 8 and leads 7 to perform a printing operation (the driving of the upper electrode 6 and other operations are obvious from the above-mentioned embodiments, so explanations thereof will be omitted).

FIGS. 7(a) and 7(b) show a third embodiment of the drive voltage supply section, in which the rotating drum type thermal recording head 1 has a sliding terminal 8 arranged in a spiral shape on the electrode section 28, The sliding terminal 8 is connected to the electrode 4 in the row direction via a lead 7 and an analog switch 29. The lead 7 portion is covered with an insulator such as glass. A fixed electrode 27 for power supply is provided at a position in contact with a sliding terminal 8 connected to an analog switch 29 connected to ↑LL12 in the row direction in which printing is performed by contacting the recording paper 30.

In the above configuration, when the printing operation is started and the drive voltage V is supplied to the analog switch 29 via the fixed electrode 27, the sliding terminal 8 and the lead 7, each switch 29a, 29b, 29e of the analog switch 29 ,2
9 d turns on next to IlK, and drive (2) and pressure V are sequentially applied to the electrodes 4 in the row direction that contact the recording paper and print. According to this embodiment, the number of sliding terminals 8 is 1/64 to V128.
It can be reduced to a certain extent.

(g) Effects of the invention The effects of the present invention are listed as follows.

(1) Since no friction is applied to the heat generating part, a wear-resistant layer can be made unnecessary.

(2) Even when a wear-resistant layer is provided, the thickness of the wear-resistant layer does not fluctuate because friction scum of the thermal paper does not occur.

(3) There will be no continuous defects in the heat generating part, so
It is possible to prevent the appearance of black or white streaks.

(4) Since the printing cycle of the heat generating part becomes longer, it is possible to eliminate the need for control that takes into consideration the adjacent effect of heat generation, the hot temperature control of the substrate, heat accumulation, etc.

As explained above, according to the thermal recording head according to the present invention, a matrix-like heat generating section is formed by a plurality of row and column direction electrodes provided on a rotating drum at intervals corresponding to a predetermined dot density. A driving voltage is applied to one row direction electrode by sliding contact, and the column direction electrodes are driven according to information, thereby avoiding frictional contact with recording paper such as thermal paper and preventing errors caused by defects in heating elements. To reduce the influence of operation and achieve uniform printing quality, and
The heating element can be driven by forming a simple tf'.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a system using a rotating drum type thermal recording head. 2(A) and 2(B) show a rotating drum type thermal recording head according to the present invention, FIG. 2(A) is a partially broken perspective view, and FIG. 2(B) is a sectional view taken along line 4(A). Figure 3 (a). (B) shows a drive system of a rotating drum type thermal recording head, and (A) is an explanatory diagram showing an example of driving a column direction electrode (upper electrode) and (B) a row direction electrode (lower electrode). FIG. 4 is a block diagram showing one embodiment of the present invention. FIG. 5 is a time chart showing the operation of the present invention. FIGS. 6(a) and 6(b) and FIG. 7(a), ←) are explanatory diagrams showing other embodiments of the drive voltage supply section. Explanation of symbols 1...Rotating drum type thermal recording head, 2...Rotating drum base, 3...Mirror layer, 4...Lower female, pole, 5...
・Resistor, 6... Upper electrode, 7... Lead, 8...
・Sliding terminal, 20... Drive circuit, 20a... Selector, 27... Fixed electrode, 28... Electric box part, 29...
・Analog switch. Figure 1 Figure 2 (b) Figure 3 (b) Figure 4 Figure 5 52゛-111 Figure 6 (a) (
Rono Figure 7 (If (0) RiQ

Claims (1)

[Scope of Claims] A thermal recording head that inputs a recording signal corresponding to information and prints on recording paper, comprising: a rotating drum that rotates in contact with the recording paper as the recording paper advances; and on the rotating drum. a plurality of row and column direction electrodes provided at intervals according to a predetermined dot density; a matrix-shaped heat generating section formed by intersections of the plurality of row and column direction electrodes; a fixed power supply electrode that slides into contact with one row-direction electrode selected from the row-direction electrodes and applies a driving voltage; and a fixed power supply electrode that drives the plurality of column-direction electrodes according to information to
1. A thermal recording head comprising: a drive section that generates heat from a heat generating section formed between two row-direction electrodes to print on the recording paper.