JPS61141580A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To find an abnormal condition early and prevent a thermal head from being damaged, by providing a feed-detecting mechanism which detects the rotation of a rotary plate rotated following a movement of an ink film and thereby detects the feed of the ink film. CONSTITUTION:Where the ink film 18 is fed normally, a take-up core 19 is rotated, and a disk 20 is also rotated, resulting in that light emitted from a light-emitting element 22 is intermittently led to a light-receiving element 23. Where the ink film 18 is not normally fed due to sticking or the like or the film 18 jams, the light from the element 22 does not reach the element 23 at all or continuously reach the element 23, so that the quantity of the light entering the element 23 is not varied with time. By electrically detecting such a condition, it is made possible to detect the jamming of the ink film.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a printer used as a terminal device for an electronic computer, and particularly relates to an ink film detection mechanism for a thermal transfer type line printer.

2. Description of the Related Art A general line-type thermal transfer printer having a conventional structure will be described below with reference to the drawings.

Figure 3 shows a cross section of a conventional line-type thermal transfer printer. In Figure 3, the box-shaped housing (1) includes:
Arm (2) with thermal head (3) fixed at the tip
is rotatably provided around a fulcrum (14). This thermal head (3) is pressed against the platen (4) by a coil spring (13) that urges the lower end of the arm (2), and a recording paper (5) and an ink film (6) are inserted between them. The ink film (6) is supplied from a supply roll (7) and wound onto a take-up roller (15) by rotation of a motor (16). The ink film (6) is attached to the base film (6a) as shown in Figure 4.
A thermofusible or sublimable ink (6b) is applied thereon.

When printing with this thermal transfer printer, rotation is transmitted to the platen drive gear (11) via the gear (9) attached to the platen drive motor (8) and the idler gear (10) that meshes with the gear (9). The platen (4) rotates in the direction of the arrow in the figure (clockwise). Coil spring (13)
is pulling the arm (2) to the left in the figure, and the arm (
2) rotates around the fulcrum (14), so the thermal head (3) is pressed against the platen (4). The recording paper (5) and ink film (6) sandwiched between the thermal head (3) and platen (4) are
) travels as the motor rotates. At this time, the thermal head (3
) when an electric signal is input to generate heat, the ink (6b) on the film base (6a) melts or sublimates and is transferred to the recording paper (5), printing characters or patterns consisting of multiple dots. will be done.

When printing is completed, the solenoid (12) moves the lower end of the arm (2) to the right in the figure against the force of the coil spring (13), and the recorded paper is ejected upward.
The print operation is completed.

Problems to be Solved by the Invention In the printer configured as described above, during printing, the base film (6a) melts due to the heat generated by the thermal head (3), and then cools and hardens.
), the ink film (6) may not be conveyed correctly, or the ink film (6) may be very thin (base film thickness is 3.5 to 10 μm, ink thickness is 3 to 5 μm). Therefore, the ink film (6) may not be fed correctly due to slight wrinkles, but in this case, even though the printer is operating, character data or pattern information will not be printed out, making the printer incomplete. It was something.

The present invention eliminates these conventional drawbacks,
To provide a thermal transfer printer that has a simple configuration and can detect a case where an ink film is not conveyed correctly and can correctly know an abnormality in the conveyance of the ink film.

Means for Solving the Problem In order to solve this problem, the printer of the present invention is provided with a rotary plate that rotates following the movement of the ink film.
The structure is such that a feed detection mechanism is provided which detects the rotation of the rotary plate and detects the feed of the ink film.

Function: With this configuration, by detecting that the rotating plate is not rotating, it is possible to immediately detect an abnormality in the conveyance of the ink film, and it is possible to detect the abnormality at an early stage.
This can prevent damage to the thermal head due to film jamming.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a perspective view showing an ink film winding section. In FIG. 1, an ink film (18) is wound up by a winding core (19), and this winding core (19)
One end is connected to a winding motor (17), and the other end is a disc (20) having a slit (21).
is installed. At this time, the first circular plate (20) and the winding core (19) are concentric. Further, a reflective portion may be formed instead of the slit (21).

The light-emitting element (22) and the light-receiving element (23) are arranged with the disk (20) sandwiched therebetween so that their element axes coincide.

If the ink film (18) is being fed normally,
The winding core (19) rotates, the disk (20) also rotates, and as a result, light emitted from the light emitting element (22) intermittently enters the light receiving element (23). If the ink film (18) is not fed properly due to sticking or the like, or if a film jam occurs, the light from the light emitting element (22) either does not enter the light receiving element (23) at all or only enters the light receiving element (23), and the light cannot be received. The amount of light entering the element (23) no longer changes over time. Ink film clogging can be detected by electrically detecting this.

Note that there are various circuits for detecting whether or not the light entering the light receiving element (23) is temporally intermittent.
An example is shown in FIG. In Figure 2, the light emitting element (22)
A light-emitting diode is used as the disk, and a phototransistor is used as the light-receiving element (23).The temporally continuous output is detected by a counting circuit, and the detection signal is high level when the disk (20) is rotating, and low level when it is stopped. .

Effects of the Invention According to the present invention, when ink film sticks during printing or -C synfilm jam occurs, an abnormality in ink film feeding can be detected immediately, and the abnormality can be detected early.
Damage to the thermal head due to film jam can be prevented.

Furthermore, since a light receiving element and a light emitting element are used as a detection mechanism for ink film feeding, the structure is non-contact with the one-rotation plate, and the detection mechanism is extremely simple and highly reliable.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is an example of a signal detection circuit, Fig. 3 is a sectional view of a conventional line type thermal transfer printer, and Fig. 4 is a configuration of a transfer ink film. FIG. (18)... Ink film, (20)... Disc (
rotating plate), (21)...slit, (22)...light emitting element, (23)...light receiving element, (24)...detection circuit representative Yoshihiro Morimoto Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A film coated with heat-melting or heat-sublimating ink and recording paper are inserted between the thermal head and the platen and pressed, and the ink is applied by the thermal head consisting of a plurality of dots that generate heat. This is a line-type thermal transfer printer that transfers images onto recording paper, and is equipped with a rotary plate that rotates to follow the movement of the ink film, and a feed detection mechanism that detects the rotation of the rotary plate and detects the feed of the ink film. Thermal transfer printer. 2. The rotary plate has a slit or a reflecting part, and the feed detection mechanism includes a light emitting element and a light receiving element arranged near the rotary plate, and a counting circuit that detects the intermittent output of the light receiving element. A thermal transfer printer according to claim 1, characterized in that: