JPH0653435B2 - Thermal printer - Google Patents

Description

TECHNICAL FIELD The present invention uses thermal printing in which a coloring pulse is applied from a thermal head to directly print on thermal paper, and thermal transfer ribbon coated with a heat-meltable ink. A thermal printer that can perform thermal transfer printing, which prints on plain paper, as desired, detects whether the thermal transfer ribbon cassette is mounted or not mounted and detects the ribbon end of the thermal transfer ribbon. The present invention relates to a thermal printer having a mechanism.

Conventional technology In conventional thermal printers, thermal printing is performed by directly contacting the thermal head with thermal paper to print directly, and thermal transfer printing is performed by printing on plain paper using thermal transfer ribbon coated with heat-melting ink. There is one in which and can be arbitrarily selected to print on both thermal paper and plain paper. Here, the thermal energy applied to the thermal head is different between the thermal printing and the thermal transfer printing due to the difference in the coloring temperature between the thermal paper and the thermal transfer ribbon. Therefore, a device for detecting whether or not the thermal transfer ribbon cassette is mounted is required as a means for distinguishing the thermal transfer printing from the thermal transfer printing. Detection of whether the thermal transfer ribbon cassette is mounted or not mounted is, as shown in FIG. 4, provided with a thermal head 3 and a ribbon take-up spool 4 which press the thermal paper or plain paper 1 against the platen 2 for printing. A mechanical switch 6 is provided on the carriage 5, and a thermal transfer ribbon cassette 9 having a thermal transfer ribbon 7 and a ribbon take-up reel hole 8 turns on the mechanical switch 6.
This is done by reading the change in the electric signal when the N / OFF is performed.

Further, at the time of heat-sensitive transfer printing, a device for detecting whether or not the heat-sensitive transfer ribbon 7 is in the ribbon end state is required.

To detect the ribbon end of the thermal transfer ribbon 7, a photo interrupter 10 is provided on the carriage 5 shown in FIG.
In addition, in order to make the photo interrupter 10 read the ribbon end state in the thermal transfer ribbon cassette 9, a ribbon end reader 11 is formed by vapor-depositing Al on the printing surface side of the ribbon for an arbitrary length from the end of the thermal transfer ribbon 7. Infrared rays emitted from the light emitting diode of the photo interrupter 10 are not reflected by the printable thermal transfer ribbon 7, but are reflected by the ribbon end reader 11 in the ribbon end state. The infrared rays received by the light receiving element 10 are converted into an electric signal and the change in the electric signal is read. As shown in FIG. 5 (A), the circuit for reading the electrical signal from the photo interrupter 10 is in a printable state, and since infrared rays emitted from the light emitting diode of the photo interrupter 10 are not reflected by the thermal transfer ribbon 7, the R _L no current flows, the voltage V _L becomes "L" across the resistor R _L, also as shown in FIG. 5 (B), the ribbon end state, emitted from the light emitting diode of the photo-interrupter 10 infrared Is a ribbon end reader 1
Since it is reflected by one, the reflected light current I _L flows through the resistor R _L is received by the light receiving element of the photo interrupter 10, the voltage V _L across the resistor R _L operates as a "H" .

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention That is, in the conventional device, a device for detecting whether the thermal transfer ribbon cassette 9 is mounted or not mounted and a device for detecting the ribbon end of the thermal transfer ribbon 7 are respectively provided. You need a total of two each.

The installation of each of the two detection devices is contrary to the market needs of the thermal printer, which requires lower cost, lighter weight, and smaller size.

Further, by providing the detection device on the carriage 5 of the thermal printer, the superposition of the carriages 5 increases and the load on the carriage motor increases, and as a result, the carriage 5
Running performance is deteriorated, which causes deterioration of print quality.

Further, by providing the detection device on the carriage 5, there is a problem that the structure of the carriage 5 becomes complicated.

In view of the above problems, the present invention provides a thermal printer that is lower in cost, lighter in weight, and more compact, has good carriage running performance and print quality, and has a simple carriage structure.

Means for Solving the Problems In order to solve the above problems, a thermal printer of the present invention is provided on a carriage for detecting a device of a thermal transfer ribbon cassette, non-installed distinction and ribbon end detection of a thermal transfer ribbon. And the photointerrupter to detect that the photointerrupter reads that the thermal transfer ribbon of the thermal transfer ribbon cassette is in a ribbon end state. A thermal transfer ribbon cassette having a ribbon end reader in which a substance that reflects infrared rays is vapor-deposited on the printing surface side of the thermal transfer ribbon, and the surface of the thermal transfer ribbon cassette facing the light receiving and emitting surface of the photo interrupter is always covered with an arbitrary area. In addition, infrared rays are applied to the surface facing the light emitting / receiving surface of the photo interrupter. The configuration is such that a reflecting plate coated with a reflecting substance is provided.

Operation According to the above configuration, the present invention can perform two types of detection with one detection mechanism, that is, detection of whether the thermal transfer ribbon cassette is mounted or not mounted and detection of the ribbon end of the thermal transfer ribbon.

Embodiment A thermal printer according to an embodiment of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1, a thermal head 2 for printing by pressing a thermal paper or plain paper 21 against a platen 22 for printing.
3 and a photo interrupter 29 on a carriage 28 having a ribbon take-up spool 27 for winding the thermal transfer ribbon 24 of the thermal transfer ribbon cassette 26 having a thermal transfer ribbon 24 and a thermal transfer ribbon take-up reel hole 25. It is provided.

In addition, in the thermal transfer ribbon cassette 26, in order to make the photo interrupter 29 read that the thermal transfer ribbon 24 is in the ribbon end state at the ribbon end, only a desired length from the end of the thermal transfer ribbon 24. Al
Is provided with a ribbon end reader 30 which is vapor-deposited. Further, half of the surface of the photo interrupter 29 facing the light receiving and emitting surface is always covered, and Al is applied to the surface of the photo interrupter 29 facing the light receiving and emitting surface. A plate 31 is provided.

In the above structure, when the thermal transfer ribbon cassette 26 is mounted, the photo interrupter 2 of FIG.
Infrared rays emitted from the light emitting diode of No. 9 are reflected by the reflecting surface 31 installed in the thermal transfer ribbon cassette 26, and the reflected light at this time has an area of the reflecting surface 31 as shown in FIG. As shown in (A), since the area of the surface of the thermal transfer ribbon cassette 26 facing the photo interrupter 29 is 1/2, the amount of light is 1/2 as compared with the total reflection surface. The reflected light in the printable state is received by the light receiving element of the photo interrupter 29, and the resistance R
_A current I _LP flows through _L and a voltage V _LP is generated.

Next, when the thermal transfer ribbon 24 is in the ribbon end state, the infrared rays emitted from the light emitting diode of the photointerrupter 29 of FIG. 2 are optional from the reflecting surface 31 and the end of the thermal transfer ribbon 24 of FIG. Is reflected by the ribbon end reader 30 in which Al is vapor-deposited on the print surface side of the ribbon, and the photo interrupter 2
The light is received by the light receiving element 9 and a current I _LI flows through the resistor R _L in FIG. 2 to generate a voltage V _LI .

Here, as shown in FIG. 2 (B), the reflected light at the ribbon end detection is the amount of light because the surface of the thermal transfer ribbon cassette 26 facing the photo interrupter 29 is a total reflection surface. Is twice as large as the reflected light in the printable state, that is, the state where the ribbon end is not present, and as a result, the relationship of V _LP <V _LI is satisfied.

Further, reference voltages Vx of the comparators X and Y in FIG.
Vy is, for example, the voltage level shown in FIG.
> Vy such that the resistors R ₁ , R ₂ and R of FIG.
₃ and R ₄ are selected and set, and the detection voltages V _LP and V _LI are set to the voltage levels shown in FIG. 3, that is, V _LI <Vx> V _LP > Vy. If the resistor R _L in FIG. 2 is selected and selected, the outputs of the comparators X and Y are as shown in the table below, and whether the thermal transfer ribbon 24 is in the ribbon end state when the ribbon cassette is mounted. Depending on the state, the logic of "H" or "L" is determined.

If the thermal transfer ribbon cassette 26 is not attached,
Since there is no reflecting surface for reflecting the infrared rays emitted from the photo interrupter 29, the logics of the comparators X and Y are both "L".

By the above method, two types of detection functions, that is, the detection of whether the thermal transfer ribbon cassette 26 is mounted or not mounted and the detection of the ribbon end of the thermal transfer ribbon 24 can be performed by the photo interrupter 29 which is one detection element. .

The logic of the comparators X and Y shown in FIG. 3 is not limited to this embodiment, and the present invention can be realized by other logic.

As described above, according to the present invention, a photo interrupter is provided on the carriage for detecting whether the thermal transfer ribbon cassette is mounted or not mounted and for detecting the ribbon end of the thermal transfer ribbon, and the thermal transfer ribbon is provided. In order to make the photointerrupter read that the thermal transfer ribbon is in the ribbon end state, a material that reflects infrared rays was vapor-deposited on the printing surface side of the thermal transfer ribbon from the end of the thermal transfer ribbon to the cassette for an arbitrary length. A material that covers the ribbon end leader and the surface of the thermal transfer ribbon cassette that faces the light receiving and emitting surface of the photo interrupter at all times, and that reflects infrared rays on the surface that faces the light receiving and emitting surface of the photo interrupter. By using a thermal transfer ribbon cassette equipped with a reflective plate coated with Since it is possible to detect whether the tape is mounted or not mounted and to detect the ribbon end of the thermal transfer ribbon with a single detection mechanism, it is lower cost, lighter and more compact.
The carriage has good running performance and print quality, and
A thermal printer having a simple carriage structure can be provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a thermal printer according to an embodiment of the present invention, FIG. 2 is a detection voltage generation circuit diagram of the thermal printer according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram for explaining the detection voltage level and logic obtained when the printer is mounted, at the end of the thermal transfer ribbon, and when printing is possible. FIG. 4 is a schematic perspective view of a conventional thermal printer, and FIG. It is a generation circuit diagram. 21 ... Thermal paper or plain paper, 22 ... Platen, 2
3 ... Thermal head, 24 ... Thermal transfer ribbon, 26
...... Thermal transfer ribbon cassette, 28 ...... Carriage, 2
9 ... Photo interrupter, 30 ... Ribbon end reader, 31 ... Reflector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-190381 (JP, A) JP-A-60-154094 (JP, A) JP-A-59-227655 (JP, A) JP-A-59- 218885 (JP, A) Actual development Sho 59-97063 (JP, U)

Claims (1)

[Claims] 1. A photointerrupter provided on a carriage for detecting whether a thermal transfer ribbon cassette is mounted or not mounted and detecting a ribbon end of the thermal transfer ribbon, and a photointerrupter for detecting the thermal transfer ribbon cassette. In order to read that the thermal transfer ribbon is in the ribbon end state, a ribbon end is formed by depositing a substance that reflects infrared rays on the printing surface side of the thermal transfer ribbon for an arbitrary length from the end of the thermal transfer ribbon of the thermal transfer ribbon cassette. A thermal transfer ribbon cassette having a reader, and a surface of the thermal transfer ribbon cassette facing the light emitting / receiving surface of the photo interrupter is always covered with an arbitrary area, and infrared rays are applied to the surface facing the light receiving / emitting surface of the photo interrupter. A thermal printer equipped with a reflector coated with a substance that reflects light.