JPS62128766A - Laser thermal transfer recording apparatus - Google Patents

Abstract

PURPOSE:To enable good recording by reduced laser output, by providing a heater for heating a thermal transfer film to predetermined temp. from temp. before the irradiation of laser. CONSTITUTION:A heat 19 for heating a platen 12 is arranged to the inner surface side of the platen 12 in a contact state and extends toward the laterals direction of the platen 12. A current is preliminarily supplied to the heater 19 before the irradiation of laser beam to heat a thermal transfer film 13 to about 60 deg.C. When laser beam is allowed to irradiate the thermal transfer film 13 in this state, the temp. of the thermal transfer film 13 further rises and a heat-meltable ink layer begins to melt when said temp. reached about 70 deg.C to apply printing transfer to recording paper 11 and, therefore, the output of the laser beam may be extremely small.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a laser thermal transfer recording device, and particularly to a laser thermal transfer recording device.

The present invention relates to a laser thermal transfer recording device using a ribbon-shaped thermal transfer film.

(Prior Art) In recent years, a laser thermal transfer recording device has been developed in which a thermal transfer film is brought into close contact with a recording paper and a laser beam is irradiated onto the thermal transfer film to perform print recording. This laser thermal transfer recording device is superior to a conventional thermal recording device using a thermal head in terms of lifespan, reliability, noise, image quality, and image preservation, and has a faster recording speed.

In such a laser thermal transfer recording apparatus, the thermal transfer film and the recording paper are each transported and wound up twice in a predetermined direction by a transporting means. That is, as shown in FIG. 7, a recording paper 2 is set on a platen platen 1 which is curved into a cylindrical shape, and a recording paper 2 is placed on the platen 2 for recording.

A ribbon-shaped thermal transfer film 3 is stretched across the recording paper 2 in the width direction of the platen 1.

The thermal transfer film 3 is wound up in its longitudinal direction (in the direction of arrow B) and is conveyed perpendicularly to the conveyance direction of the recording paper 2 (in the direction of arrow A). A laser beam 5 deflected by a deflector consisting of a rotating polygonal mirror 4 is irradiated onto the thermal transfer film 3, thereby performing predetermined recording.

However, in the conventional apparatus, it is necessary to generate a high-output laser beam to melt the ink layer of the thermal transfer film, making the entire apparatus large and expensive. In particular, there is a certain limit to the output power of semiconductor lasers, and it is often impossible to use small, low-cost semiconductor lasers.

(Objective) Therefore, an object of the present invention is to provide a laser thermal transfer recording device that can perform recording with a small laser output.

(Structure) Below, the structure of the present invention will be explained in detail based on each embodiment.

As shown in FIGS. 1 and 2, the recording paper 11 is placed on a platen 12 of a predetermined length, which is curved so as to constitute a part of a cylindrical body, and is transferred to the platen by a transport mechanism (not shown). It is sent in the direction indicated by the arrow along the track ml of No. 12.

Furthermore, a ribbon-shaped thermal transfer film 13 is stretched obliquely over the recording paper 11 at a predetermined angle with respect to the width direction of the platen 12, and is pressed against the recording paper 11 side with a predetermined tension. The paper is then transported and wound up at a predetermined speed in the longitudinal direction, that is, in the direction of arrow B', by a transport and winding mechanism (not shown). Therefore, the above-described feeding direction of the recording paper 11 (direction of arrow entry) and feeding direction of the thermal transfer film 13 (direction of arrow B') are not perpendicular to each other.

Further, the laser light generated from the semiconductor laser 14 is as follows.

After being collimated by the collimator lens 15 and deflected by a deflector consisting of a rotating polygon mirror 16, the fθ lens 17
The ink is further corrected and shaped by the cylindrical lens 18 and irradiated onto the thermal transfer film 13, whereby the ink layer of the thermal transfer film 13 is appropriately melted and predetermined recording is performed on the recording paper 11. It is now possible to

Furthermore, as shown in FIG. 3, a heater 19 for heating the platen 12 is placed in contact with the inner surface of the platen 12 (bottom side in FIG. 3). This heater 19 is made of a rod-shaped resistor and extends in the width direction of the platen 12. Then, 1 electric current is applied to generate heat, heat the platen 12, and heat the thermal transfer film 1 on the platen 12.
3 to a predetermined temperature. In this embodiment, conditions are set so that the entire surface of the thermal transfer film 13 is heated to about 60°C.

In the laser thermal transfer recording apparatus having such a configuration, the heater 19 is energized from the laser beam irradiation surface to heat the thermal thermal transfer film 135i to about 60°C. When the thermal transfer film 13 is irradiated with laser light in this state, the temperature of the thermal transfer film 13 is further increased, and when the temperature reaches approximately 70°C, the heat-melting ink layer starts to melt and is transferred onto the recording paper. Print transfer is performed.

In this case, since the amount of temperature rise of the thermal transfer film 13 by the laser beam is only about 10° C. (from 60° C. to 70° C.), the output of the laser beam may be extremely small.

That is, the preheating temperature of the thermal transfer film 13 is To("C
) and the melting start temperature is T ('C), the laser output required for recording is proportional to T"-To2.

This state is shown in FIG.

In Figure 4, the vertical axis shows the laser output (mW), the horizontal axis shows the laser scanning speed (A4.cρl11), and a line is drawn using the preheating temperature TO of the thermal transfer film 13 as a parameter. It is. Note that the unit of the horizontal axis is A4. cpm represents the number of A4 sheets that can be recorded per minute. As can be seen from this figure, when the preheating temperature To of the thermal transfer film 13 is increased sequentially from 20° C. to 40° C. to 160° C., the required laser output is reduced accordingly.

Further, in the above embodiment, a rod-shaped heater 19 is used as the heater, but various heaters such as a planar heater or a heater made of a rubber resistor may be used. Furthermore, the platen 12 itself may be constructed from a self-temperature-controlled PTC thermistor to serve as a heater. P.T.
The C thermistor is an oxide semiconductor ceramic whose main component is barium titanate, and generates heat when a predetermined voltage is applied. Note that if an appropriate PTC thermistor is selected, the predetermined temperature can maintain thermal equilibrium and maintain a substantially constant temperature.

Furthermore, the present invention is applicable not only to a device using a deflector made of the rotating polygon mirror 16 as described above, but also to a device using a hologram scanner 23 as a deflector as shown in FIGS. 5 and 6. 6 hologram scanner 23 that can
Holograms serving as deflection elements are arranged on a disk substrate 24. Laser light from a laser light source (not shown) passes through a cylindrical lens 25, is reflected by a plane mirror 26, enters one of the holograms, and is emitted from the hologram. After the diffracted light is reflected by the plane mirror 27, f
The light is focused into a spot through a θ lens 28 and a cylindrical lens 29.

Furthermore, as a light source, a semiconductor laser as mentioned above,
In addition to YAG lasers and carbon dioxide lasers, it is also possible to use helium-neon lasers, argon ion lasers, helium-cadmium lasers, and the like. In this case, as shown in FIG. 7, the laser beam emitted from the laser 31 passes through the beam compressor 32, AO modulator 33, beam expander 34, and cylindrical lens 35, and is deflected by the rotating polygon tn36. Thereafter, the light passes through the toroidal lens 37 and the fO lens 38 and is irradiated onto the recording material 39.

(Effects) As described above, the laser thermal transfer recording device according to the present invention is equipped with a heater that raises the temperature to a predetermined temperature so that the thermal transfer film can be easily melted. The heat-melting ink layer can be melted well.

A small and low-cost laser thermal transfer recording device can be obtained. In particular, it is possible to realize a device using a low-output semiconductor laser.

[Brief explanation of drawings]

1 and 2 are perspective views of a recording device according to an embodiment of the present invention, FIG. 3 is an enlarged cross-sectional view of the recording section, FIG. 4 is a diagram showing the required laser output, and FIG. 6 and 7 are perspective views showing examples of application to other optical systems;
The figure is a perspective view of a general laser thermal transfer recording device. 1■... Recording paper, 12... Platen, 13...
...Thermal transfer film, 14.31...Laser, 1
5... Collimator lens, 16... Rotating polygon mirror, 17.28.38... fθ lens, 18.25.2
9.35... Cylindrical lens, 19...
Heater, 23... Hologram scanner. 24...disk, 26.27...plane mirror,
32... Beam compressor, 33... AO modulator, 34... Beam expander, 37...
toroidal lens. Circulation σ Diagram Z Ui 4 Shrine

Claims (1)

[Scope of Claims] 1. A laser that is configured to bring a ribbon-shaped thermal transfer film into close contact with recording paper, wind it up and convey it, and irradiate the thermal transfer film with laser light to transfer an information image onto the recording paper. In the thermal transfer recording device, the thermal transfer film includes:
A laser thermal transfer recording apparatus characterized in that a heater is attached to raise the temperature of the thermal transfer film to a predetermined temperature before laser irradiation. 2. The laser thermal transfer recording apparatus according to claim 1, wherein the heater comprises a heater provided in contact with a platen that supports the recording paper. 3. The laser thermal transfer recording apparatus according to claim 1, wherein the heater comprises a platen that supports the recording paper and is composed of a self-temperature-controlled PTC thermistor.