JPH0653434B2 - Thermal printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention generally 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 is used. In a thermal printer capable of printing by selectively selecting thermal transfer printing for printing on paper, detection of whether the thermal transfer ribbon cassette is mounted or not mounted and detection of the ribbon end of the thermal transfer ribbon The present invention relates to a thermal printer having a detection 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, as a means for distinguishing between thermal printing and thermal transfer printing, a device for detecting whether or not the thermal transfer ribbon cassette is mounted is required. As shown in FIG. 9, the detection of whether the thermal transfer ribbon cassette is mounted or not mounted is 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 thermal transfer printing, a device for detecting whether or not the thermal transfer ribbon is in the ribbon end state has been required.

To detect the ribbon end of the thermal transfer ribbon, a photo interrupter 10 is provided on the carriage 5 shown in FIG. 9, and the thermal transfer ribbon cassette 9 is read by the thermal interrupt ribbon 10 so that the photo interrupter 10 can read the ribbon end state. A ribbon end reader 11 in which Al is vapor-deposited is provided on the printing surface side of the ribbon for an arbitrary length from the end of the ribbon, and infrared rays emitted from the light emitting diode of the photo interrupter 10 are not reflected by the printable thermal transfer ribbon 7. However, when the ribbon end state is reached, the light is reflected by the ribbon end reader 11, so infrared rays received by the light receiving element of the photo interrupter 10 are converted into an electric signal and the change in the electric signal is read. There is. As shown in FIG. 10 (A), the circuit for reading the electric 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 resistance R _L No current flows through the resistor R _L , the voltage V _L across the resistor R _L becomes “L”, and as shown in FIG. 10 (B), in the ribbon end state, infrared rays emitted from the light emitting diode of the photo interrupter 10 are , Ribbon end reader 11
Since reflected by 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 to "H".

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention That is, in the conventional device, one device for detecting whether the thermal transfer ribbon cassette is mounted or not mounted and one device for detecting the ribbon end of the thermal transfer ribbon are provided. A total of two is required, and the installation of each of the two detection devices has a problem that it is against the market needs of the thermal printer, which requires lower cost, lighter weight, and smaller size.

In view of the above problems, the present invention provides a low cost, lightweight, compact thermal printer.

Means for Solving the Problems In order to solve the above problems, a thermal printer according to the present invention is provided on a carriage for detecting whether a thermal transfer ribbon cassette is mounted or not mounted and for detecting a ribbon end of a thermal transfer ribbon. The photointerrupter provided and the infrared ray emitted from the photointerrupter are reflected so that the photointerrupter can read that the thermal transfer ribbon of the thermal transfer ribbon cassette is in the ribbon end state. A ribbon end reader is formed by vapor-depositing an infrared-reflecting substance on the printing surface side of the heat-sensitive transfer ribbon from the end of the heat-sensitive transfer ribbon for an arbitrary length, and having an arbitrary number of slits in the vapor-deposited portion of the infrared-reflecting substance. The thermal transfer ribbon cassette and the front carriage on the same carriage as the photo interrupter The photointerrupter is provided with a reflector having an arbitrary area which can be concealed by mounting or not mounting the thermal transfer ribbon cassette at a position at an arbitrary distance from the light emitting / receiving surface.

Operation According to the above-described structure, the present invention can perform two types of detection functions, 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 with one detection mechanism.

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, thermal paper or plain paper 21
A thermal head 23 for printing by pressing the platen 22 against the platen 22, a thermal transfer ribbon 24, and a ribbon take-up spool for winding the thermal transfer ribbon 24 of a thermal transfer ribbon cassette 26 having a thermal transfer ribbon take-up reel hole 25. On the carriage 28 having the photo-interrupter 29, the photo-interrupter 29 has an arbitrary area which is vertically movable with respect to the upper surface of the carriage 28 at an arbitrary distance from the front surface of the light-receiving / emitting surface, and the photo-interrupter 29 is provided. Photo-interrupter 29 for reflecting infrared rays emitted from
A reflective plate 30 having Al vapor-deposited is provided on the surface facing the light emitting / receiving surface.

This reflection plate 30 is used for the photo interrupter 2 when the thermal transfer ribbon cassette 26 is not mounted on the carriage 28.
When the ribbon cassette 26 is mounted on the carriage 28, the ribbon cassette 26 is set to be pushed downward by the ribbon cassette 26.

In addition, the thermal transfer ribbon 24 of the thermal transfer ribbon cassette 26 has an arbitrary length from the end of the thermal transfer ribbon,
The photo interrupter 2 is provided on the printing surface side of the thermal transfer ribbon.
A ribbon end reader 31 vapor-deposited with Al is provided to reflect the infrared rays emitted from 9.

As shown in FIG. 2, the ribbon end leader 31 has slits (in this embodiment, Al non-deposited portion) having an arbitrary width c at an arbitrary interval b in an arbitrary length a of the ribbon end leader 31. Two are provided.

Here, the relationship among the length a, the interval b, and the width c in the ribbon end leader 31 is as shown in FIG. 3, where the Al vapor deposition start portion of the ribbon end leader 31 of the thermal transfer ribbon 24 is taken as the thermal transfer ribbon 24 is wound. The time required for the above to reach the heat-generating resistor of the thermal head 23 is T ₁ , and the photo interrupter 29 uses the reflected light to detect the ribbon end of the thermal transfer ribbon 24. Let T ₂ be the time required for the ribbon end reader 31 having the length of a in FIG. 2 to pass between the length d of the opening of the surface of the photo interrupter 29 facing the light receiving / emitting surface of the photo interrupter 29. ,
The length of a in FIG. 2 is set so that T ₁ > T ₂ ,
Also, as shown in FIG. 4, the ribbon end signal receiving unit from the photo interrupter 29 changes the ribbon end signal, for example, logic "H", for a sufficient period of time for recognition.
The distance b and the width c in FIG. 2 are set so that "L" can be maintained.

Further, when the ribbon end of the thermal transfer ribbon 24 is detected, the infrared rays emitted from the light emitting diode of the photo interrupter 29 in FIG. 5 are reflected by the ribbon end reader 31 of the thermal transfer ribbon 24 and received by the light receiving element of the photo interrupter 29. current _{I L} in is the resistance _{R L}
And the voltage V _L is generated, but at this time, the detection voltage V _L
Does not detect the ribbon end state immediately after the change of the logic "L" → "H" is detected by the receiving unit of FIG. 4, but the logic "L" is detected after the logic "H" is detected as shown in FIG. The receiver is set so that the ribbon end state is not detected until the two pulse signals 32 are detected.

According to the above setting, when the ribbon end is detected, the detection signal in which “H” and “L” are combined as shown in FIG. 6A is read, and when printing is possible, as shown in FIG. 6B. A constant "L" detection signal is obtained. Further, when the thermal transfer ribbon cassette is not attached, a detection signal having a constant logic "H" is read as shown in FIG. 6 (B).

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 reflection plate 30 shown in FIG. 1 is a method of making it movable upside down by mounting or not mounting the thermal transfer ribbon cassette as shown in FIG. 7, and as shown in FIG.
The above-mentioned function can be realized by a method in which 0 is rotated by the thermal transfer ribbon cassette 26, and the number of slits (Al non-deposited portion) provided in the ribbon end reader 31 shown in FIG. 2 is not limited to that in this embodiment. It can be realized by other quantities.

EFFECTS OF THE INVENTION As described above, according to the present invention, a photointerrupter used to detect whether the thermal transfer ribbon cassette is mounted or not mounted on the same carriage and to detect the ribbon end of the thermal transfer ribbon, and one optional sheet. In addition, a reflective plate having an area of 1 is provided, and in order to make the photointerrupter read the ribbon end detection of the heat-sensitive transfer ribbon, the heat-sensitive transfer ribbon is vapor-deposited with a substance that reflects infrared rays for an arbitrary length from the end of the heat-sensitive transfer ribbon. In addition, by using the thermal transfer ribbon cassette provided with a ribbon end reader having an arbitrary number of slits in the vapor deposition portion of the infrared reflective material, the detection and the detection of whether the thermal transfer ribbon cassette is mounted or not mounted is used. Since the ribbon end of the thermal transfer ribbon can be detected by one detection mechanism, it is possible to reduce the cost, weight and
It is possible to provide a compact thermal printer.

[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 an enlarged view of a ribbon end leader of a thermal transfer ribbon, and FIG. 3 is a slit interval provided in the ribbon end leader of FIG. The figure explaining the relationship between the width setting and the detection signal at the ribbon end, FIG. 4 is the waveform diagram of the detection signal obtained by the ribbon end reader of FIG. 2,
FIG. 5 is a detection voltage generation circuit diagram of a thermal printer according to an embodiment of the present invention, FIG. 6 (A) is a ribbon end of a thermal transfer ribbon, (B) is a printable state, and (C) is a thermal transfer. FIG. 7 is a waveform diagram of a detection signal obtained when the ribbon cassette is not mounted. FIG. 7 is a schematic perspective view of a thermal printer according to an embodiment when the reflecting plate of the present invention is movable up and down. FIG. 8 shows the reflecting plate of the present invention. FIG. 9 is a schematic perspective view of a thermal printer according to an embodiment when it is rotatably movable, FIG. 9 is a schematic perspective view of a conventional thermal printer, and FIG.
(B) is a detection voltage generation circuit diagram of a conventional thermal printer. 21 ... Thermal paper or plain paper, 22 ... Platen, 2
3 ... Thermal head, 24 ... Thermal transfer ribbon, 26
...... Thermal transfer ribbon cassette with ribbon end reader, 28 ...... Carriage, 29 ...... Photo interrupter, 30 ...... Reflector, 31 ...... Ribbon end reader,
32 ... "L" pulse signal.

 ─────────────────────────────────────────────────── ─── 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 photo interrupter provided on a carriage for detecting whether a thermal transfer ribbon cassette is mounted or not mounted and for detecting a ribbon end of the thermal transfer ribbon, and infrared rays emitted from the photo interrupter are reflected. In order to make the photointerrupter read that the thermal transfer ribbon of the thermal transfer ribbon cassette is in the ribbon end state, the printing surface side of the thermal transfer ribbon of any length from the end of the thermal transfer ribbon of the thermal transfer ribbon cassette A thermal transfer ribbon cassette having a ribbon end reader having an arbitrary number of slits on the vapor-deposited portion of the infrared reflecting material, and on the same carriage as the photo interrupter.
A thermal printer comprising a photoreflector at a position at an arbitrary distance from a light emitting / receiving surface, and a reflector having an arbitrary area which can be concealed by mounting or not mounting the thermal transfer ribbon cassette.