JPH0732623A - Thermal recording method and apparatus - Google Patents

Abstract

PURPOSE:To easily and accurately control a thermal recording material to desired preheating temp. and to simplify constitution. CONSTITUTION:A heating means 12 applying heat energy to a thermal recording material S to heat the same to predetermined color forming temp., a preheating means 14 preheating the thermal recording material S to predetermined temp. below the color forming temp., a detection means 16 detecting the transmissivity of the preheated part of the thermal recording material S and the control part 19 for controlling the heating means 12, the preheating means 14 and the detection means 16 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording method and apparatus for recording an image or the like by applying heat energy to a heat-sensitive recording material in a preheated state.

[0002]

2. Description of the Related Art Thermal recording apparatuses for imparting thermal energy to a thermal recording material to record an image or the like have been widely used. For example, a laser capable of high-speed recording has appeared by using a laser as a heat source (Japanese Patent Laid-Open No. 50-23617).
JP-A-58-94494 and JP-A-62-7798.
3 and JP-A-62-78964).

The present applicant has applied a color developing agent, a color developing agent and a light absorbing dye on a support as a heat sensitive recording material which is applied to such a thermal recording apparatus and is capable of recording a good image with high quality. A material that develops and develops a color at a concentration according to the added heat energy has been developed and applied for a patent (Japanese Patent Application No. 3-6).
No. 2684, Japanese Patent Application No. 3-187494).

In this heat-sensitive recording material, microcapsules containing at least a basic dye precursor, a color developer and a light-absorbing dye are dissolved in an organic solvent which is hardly soluble or insoluble in water and then emulsified and dispersed. The heat-sensitive layer is formed by applying a coating liquid containing the emulsion.

[0005]

By the way, in order to maintain a stable storage state, such a heat-sensitive recording material is constructed so as not to develop color with low heat energy. Therefore, a considerable amount of heat energy is required to obtain the desired color development state. As a result, the dynamic range is narrowed by the threshold value of heat energy until color development, and it is difficult to obtain a high gradation image. In addition, the burden on the device side for color development becomes considerably large.

Therefore, the applicant of the present invention proposes a thermal recording apparatus constructed so that the thermal recording material is preheated to a predetermined temperature lower than the coloring temperature and then the thermal recording material is scanned with a laser beam to develop a color. (Japanese Patent Application No. 5-3888)
(See No. 8). As a result, it is possible to obtain an image with high gradation and high precision easily and with high precision, and to reduce the burden on the heating means.

According to the present invention, when preheating a heat-sensitive recording material of this type, the heat-sensitive recording material can be easily and accurately controlled to a desired preheating temperature, and the structure can be simplified. It is an object to provide a method and a device.

[0008]

In order to achieve the above object, the present invention applies heat energy to a heat-sensitive recording material having a color former and a developer on a support through heating means. A heat recording method for recording by heating the heat sensitive recording material to a predetermined color development temperature, wherein the heat sensitive recording material is preheated to a predetermined temperature lower than the color development temperature by a preheating means; A step of detecting a transmittance or a reflectance of a preheated portion of the material, and a step of controlling the preheating means and / or the heating means based on the detected transmittance or the reflectance. And

After the heat-sensitive recording material is preheated,
It is preferable to provide a step of performing recording by irradiating the thermosensitive recording material with a laser beam excluding a portion to be inspected, and detecting the transmittance or the reflectance of the portion to be inspected after the recording.

After the heat-sensitive recording material is preheated,
A step of irradiating a laser beam of a constant intensity on a portion to be inspected of the thermosensitive recording material and irradiating a laser beam of a predetermined intensity on a recording portion of the thermosensitive recording material to perform recording;
After the recording, it is preferable to detect the transmittance or the reflectance of the inspected portion irradiated with the laser beam having the constant intensity.

Further, according to the present invention, heat energy is applied to a heat-sensitive recording material having a color former and a developer on a support through heating means to bring the heat-sensitive recording material to a predetermined color development temperature. A thermal recording device for heating and recording, wherein preheating means for preheating the thermosensitive recording material to a predetermined temperature lower than a coloring temperature and detecting transmittance or reflectance of a preheated portion of the thermosensitive recording material. And a detection unit.

Further, it is preferable that the thermal recording apparatus comprises a control means for controlling the preheating means on the basis of the transmittance or the reflectance detected by the detecting means.

Furthermore, it is preferable that the thermal recording apparatus further comprises control means for controlling the heating means based on the transmittance or reflectance detected by the detecting means.

[0014]

In the thermal recording method and apparatus according to the present invention, the thermal recording material having the color former and the developer on the support is preheated to a predetermined temperature lower than the color development temperature by the preheating means. The material itself is heated to a temperature immediately before the color development temperature, and the color is reliably developed by applying a relatively small amount of heat energy. At that time, the transmittance or reflectance of the preheated portion of the heat-sensitive recording material is detected, and the preheating means and / or the heating means is controlled based on the detected transmittance or reflectance. Therefore, the heat-sensitive recording material can be reliably maintained in a desired preheated state, and a high-quality recorded image can be easily obtained.

[0015]

The thermal recording method and apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. In the following examples, the heating means is controlled to perform multi-gradation recording on the heat-sensitive recording material.

In FIG. 1, reference numeral 10 indicates a thermal recording apparatus according to an embodiment of the present invention. This thermal recording device 10
Is for recording an image or the like by scanning the heat-sensitive recording material S, which is sub-scanned and conveyed in the direction of arrow B, in the direction of arrow A by the laser beam L, and applying heat energy to the heat-sensitive recording material S to obtain the heat-sensitive recording material. A heating means 12 for heating the recording material S to a predetermined coloring temperature, a preheating means 14 for preheating the thermosensitive recording material S to a predetermined temperature lower than the coloring temperature, and a transmittance of a preheated portion of the thermosensitive recording material S. Detecting means 1 for detecting
6 and a control unit 19 for controlling the heating means 12, the preheating means 14, the detection means 16 and the like.

The heating means 12 includes a laser diode 18 for outputting a laser beam L, a collimator lens 20 for collimating the laser beam L, a cylindrical lens 22, a reflecting mirror 24, and a polygon for deflecting the laser beam L. The mirror 26, the fθ lens 28, and the cylindrical lens 22 cooperate with each other to form the polygon mirror 26.
And a cylindrical mirror 30 that corrects the face tilt of the. The laser diode 18 is controlled by the control unit 19 via the driver 32.

The preheating means 14 is provided with a preheating light source 36 and a reflecting plate 38 which are arranged at a predetermined distance from the heat-sensitive recording material S.
The variable aperture 40 is disposed between the preheat light source 36 and the thermal recording material S. As shown in FIG. 2, the variable aperture 40 includes a fixed member 42 and a variable member 44, and the variable member 44 is configured to be movable in the arrow direction via a drive mechanism 46 such as a rack and pinion.

The detecting means 16 comprises a light emitting portion 50 and a light intensity detector 52 which face each other with the portion 48 to be inspected of the thermosensitive recording material S preheated to a predetermined temperature by the preheating means 14 therebetween. The light emitting unit 50 is, for example, a laser diode with a collimator, and the light intensity detector 52 is, for example, a photodiode.

The heat-sensitive recording material S comprises a transparent support 54 and a heat-sensitive layer 56 formed on the support 54. The heat-sensitive layer 56 is provided with a color former, a developer and a laser beam L. It is composed of a material containing a light absorbing dye that absorbs and converts this into heat energy. For this material,
As mentioned above, Japanese Patent Application No. 3-62684 and Japanese Patent Application No. 3-26884.
What was described in 187494 etc. can be used.

Next, the thermal recording apparatus 1 thus constructed
The operation of 0 will be described in relation to the thermal recording method according to the first embodiment.

While the thermosensitive recording material S is sub-scanned and conveyed in the direction of arrow B under the action of the control section 19 through a conveying mechanism (not shown), the thermosensitive recording material S is conveyed through the preheating light source 36 constituting the preheating means 14. Radiantly heated. by this,
The thermosensitive recording material S is preheated to a temperature just before color development.

At substantially the same time as the preheating, the control section 19 drives the laser diode 18 via the driver 32. The laser diode 18 outputs a laser beam L modulated according to the gradation of the image recorded on the thermosensitive recording material S. The laser beam L is collimated by the collimator lens 20 and then guided to the polygon mirror 26 via the cylindrical lens 22 and the reflection mirror 24. The polygon mirror 26 rotates at a high speed, and the laser beam L reflected by the reflecting surface thereof is guided to the thermosensitive recording material S via the fθ lens 28 and the cylindrical mirror 30 and is sub-scanned and conveyed in the direction of arrow B. The heat-sensitive recording material S which is in the main scanning direction is scanned in the direction of arrow A. At that time, the laser beam L is formed on the heat-sensitive layer 56 of the heat-sensitive recording material S.
By applying a predetermined heat energy corresponding to the coloring temperature, a gradation image is recorded.

Here, the heat-sensitive recording material S has a preheating means 14
Since it is preheated to the temperature T1 (see FIG. 3) through the laser diode 18, it is not necessary to control the laser diode 18 in a wide range from the room temperature where the thermal recording device 10 is installed to the temperature T2. Therefore, the laser diode 18 is controlled in the range of the temperature T1 to the temperature T2, and a high gradation image is accurately formed. Further, since the laser diode 18 is not required to have a high output, the entire structure of the thermal recording device 10 is simplified and the cost is reduced. The temperature T1 is set between 40 and 275 [deg.] C. according to the color development characteristics of the heat-sensitive recording material S, and the preheating time is set to 30 from the viewpoint of throughput.
It is desirable to set it to less than a second. More preferably,
Since the glass transition temperature of the microcapsule is 70 to 150 ° C., the temperature T1 is preferably set to 70 to 150 ° C. Further, the preheating time is preferably 10 seconds or less because the shorter the time period, the less fog tends to occur.

The inspected portion 48 of the thermal recording material S is preheated to the temperature T1 by the preheating means 14 and then arranged corresponding to the detecting means 16 without being irradiated with the laser beam L. In the detection means 16, the detection light L0 is derived from the light emitting section 50 toward the light intensity detector 52, and the detection light L0 is transmitted through the inspected portion 48 and received by the light intensity detector 52, It is detected as the intensity of transmitted light.
At that time, as shown in FIG. 4, the transmittance of the heat-sensitive recording material S was low at room temperature T0, but increased as the temperature increased, and then decreased at maximum temperature T1 immediately before color development and then decreased. Become. This is because the heat-sensitive layer 56 becomes transparent from the cloudy state due to the temperature rise, and then the color is developed.

Therefore, if the transmittance of the detection light L0 received by the light intensity detector 52 is always the maximum value, the thermosensitive recording material S can be surely maintained in the best preheating state. Therefore, the radiant heating temperature of the preheating light source 36 is controlled via the control unit 19, or the variable member 44 is moved in the arrow direction in FIG. By adjusting the aperture 40, the preheating temperature of the thermosensitive recording material S is controlled.

In this case, in the first embodiment, the preheating light source 3
Since the thermal recording material S is preheated in a non-contact state by the radiant heating of 6, the heating temperature by the laser beam L is transmitted from the thermal recording material S to other members under the adiabatic action of air, and the heating temperature is increased. It never drops. Moreover, the temperature of the heat-sensitive recording material S that has been preheated in the non-contact state can be accurately detected through the non-contact type detection means 16,
There is an effect that a complicated and expensive detection device such as a radiation thermometer can be eliminated.

The preheating means 14 is provided with a preheating light source 36. Instead of the preheating light source 36, a non-contact type preheating source such as an infrared heater or a warm air heater is used, or a contact with a heat roller or the like is used. A mold preheat source may be used.

Further, the light emitting section 50 constituting the detecting means 16
The light intensity detector 52 and the light intensity detector 52 are arranged in a direction orthogonal to the surface of the heat-sensitive recording material S, but the detection light L0 is configured to irradiate the surface of the heat-sensitive recording material S at an angle. Good. Further, although the detection means 16 is a transmission type, it is also possible to use a reflection type detection means by making the support 54 of the thermal recording material S non-transparent.

Further, in the present embodiment, the side portion of the heat-sensitive recording material S is irradiated with the laser beam L to form the inspected portion 48 for preheating temperature control in which image recording is not performed, but as shown in FIG. By measuring the transmittance of the heat-sensitive recording material S between the preheating means 14 and the irradiation position of the laser beam L, it is possible to perform recording on the entire surface without leaving the inspected portion 48.

Next, a thermal recording method according to the second embodiment will be described with reference to FIGS. In the second embodiment, the same thermal recording device 10 as the thermal recording method according to the first embodiment can be used.

Therefore, first, the thermal recording material S is indicated by the arrow B.
While being conveyed in the sub-scanning direction, it is heated to a predetermined temperature (less than the color development temperature) via the preheating light source 36 constituting the preheating means 14. Then, a laser beam L is output from the laser diode 18 which constitutes the heating means 12. The laser diode 18 irradiates the laser beam L to heat the inspected portion 48 of the thermal recording material S to a predetermined temperature T1 for preheating.
It is controlled so that the recording portion of the heat-sensitive recording material S is colored while being heated to 1.

That is, the portion to be inspected 48, which is the non-recording portion of the thermal recording material S, is preheated by being irradiated with the laser beam L having a constant intensity, while the recording portion of the thermal recording material S is imaged at this constant intensity. An image is recorded by irradiating a laser beam L having a predetermined intensity added with the intensity required for recording.

Then, the transmittance of the inspected portion 48 preheated by the irradiation of the laser beam L having a constant intensity is detected by the detecting means 16, and the laser beam having a constant intensity is set so that the transmittance becomes the maximum value. Correct the output value of L. In addition, the laser intensity of the image recording portion added to the recording portion of the thermosensitive recording material S is also corrected according to the output correction of the laser beam L having the constant intensity.

As described above, in the second embodiment, since the preheating state of the thermosensitive recording material S is controlled by the output correction of the laser beam L, the response is more reliable and reliable than the case where the preheating light source 36 is controlled. It becomes possible to control.

By the way, in the second embodiment, the inspected portion 48 is so arranged that the transmittance of the inspected portion 48 is maximized.
The intensity of the constant output laser beam L for irradiating the image is controlled, and the laser intensity signal for image recording for illuminating the image recording area is also corrected accordingly to obtain a stable gradation image. A laser that is in charge of output irradiation of a constant intensity and a laser for recording an image in the image area are independently provided,
It is possible to drive them independently (hereinafter referred to as the third embodiment).

In this case, the laser beam L is a composite wave beam of a laser beam having a constant intensity required for preheating and a laser beam having an intensity required for image recording. Therefore, in the third embodiment, it is only necessary to control the intensity of the laser beam required for preheating so that the transmittance obtained from the inspected portion 48 becomes maximum, and an optimum preheating state can be obtained and the image can be obtained. There is an effect that it is possible to easily record a high-quality image with simple control because signal correction is unnecessary.

Further, since the laser diode 18 is controlled, the response is improved at a stroke as compared with the case of controlling the preheating light source 36, and fine temperature control can be surely performed in a short time.

[0039]

According to the thermal recording method and apparatus of the present invention, the following effects can be obtained.

Since the transmittance or reflectance of the preheated portion of the heat-sensitive recording material is detected and the preheating means and / or the heating means is controlled based on the detected transmittance or reflectance, it is possible to simplify the operation. With the constitution, the heat-sensitive recording material can be controlled to a desired preheat state with high accuracy, and a high-quality recorded image can be easily and efficiently obtained. Further, the detecting means is a sensor for detecting the transmittance or the reflectance, and the advantage that the structure of the detecting means itself is simplified and the cost is low can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a configuration of a thermal recording device according to the present invention.

FIG. 2 is a partial front view of the thermal recording apparatus.

FIG. 3 is an explanatory diagram of color forming characteristics of a thermosensitive recording material.

FIG. 4 is an explanatory diagram of the relationship between the transmittance and the temperature of the thermosensitive recording material.

FIG. 5 is a partial front view of another thermal recording apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Thermal recording device 12 ... Heating means 14 ... Preheating means 16 ... Detecting means 18 ... Laser diode 19 ... Control part 36 ... Preheating light source 40 ... Variable aperture 48 ... Inspected part 50 ... Light emitting part 52 ... Light intensity detector 54 ... Support 56 ... Thermosensitive layer S ... Thermosensitive recording material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B41M 5/26 B41J 3/20 117 Z 6956-2H B41M 5/18 Q

Claims (6)

[Claims] 1. A thermal recording material having a color former and a color developer on a support is heated by heating means to heat the thermal recording material to a predetermined color development temperature for recording. A thermal recording method for performing, wherein the heat-sensitive recording material is preheated by a preheating means to a predetermined temperature lower than the coloring temperature, and a step of detecting the transmittance or reflectance of the preheated portion of the heat-sensitive recording material. A step of controlling the preheating means and / or the heating means on the basis of the detected transmittance or reflectance, and a thermal recording method. 2. The method according to claim 1, further comprising a step of performing recording by irradiating a laser beam on the thermosensitive recording material except for a portion to be inspected after the thermosensitive recording material is preheated, and after the recording. A thermal recording method, characterized in that the transmittance or reflectance of a portion to be inspected is detected. 3. The method according to claim 1, wherein after the heat-sensitive recording material is preheated, a portion to be inspected of the heat-sensitive recording material is irradiated with a laser beam having a constant intensity, and the recording portion of the heat-sensitive recording material is irradiated. A thermal recording method comprising a step of irradiating a laser beam of a predetermined intensity for recording, and detecting the transmittance or reflectance of the inspected site irradiated with the laser beam of the constant intensity after the recording. 4. A thermal recording material having a color former and a color developer on a support is heated by heating means to heat the thermosensitive recording material to a predetermined color development temperature for recording. A thermal recording device for performing, the heat-sensitive recording material, preheating means for preheating to a predetermined temperature less than the coloring temperature, a detection means for detecting the transmittance or reflectance of the preheated portion of the heat-sensitive recording material, A thermal recording device comprising: 5. The apparatus according to claim 4, wherein the thermal recording device comprises control means for controlling the preheating means based on the transmittance or reflectance detected by the detecting means. Recording device. 6. The apparatus according to claim 4, wherein the thermal recording device comprises a control means for controlling the heating means based on the transmittance or reflectance detected by the detection means. Recording device.