JPH05262018A - Recording device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a recording device capable of performing dot recording and erasing corresponding to the size of a heating resistor of a thermal head, and improving durability of repetitive recording on a recording medium. .. A recording device for recording or erasing a visible image by using a thermal head on a recording medium capable of recording or erasing a visible image by making the liquid cloudy or transparent by controlling thermal energy. In order to record or erase a visible image on a recording medium, a thermal head having a heating resistor 41 that generates a plurality of hot spots H1 to H4 corresponding to one image point forming region which is a visible image recording unit is used. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides, for example, whitening or transparency by controlling heat energy,
The present invention relates to a recording device for recording or erasing a visible image on a recording medium capable of recording or erasing a visible image repeatedly by using a thermal recording means such as a thermal head.

[0002]

2. Description of the Related Art A conventional hard copy forms an image on a recording medium such as paper from the outside with a visual material such as ink or toner, or, like a thermal recording paper,
A permanent image is recorded by providing a recording layer on a substrate such as paper and forming a visible image on the recording layer.

However, with the recent construction of various network networks and the widespread use of facsimiles and copiers, the rapid increase in the consumption of these recording media causes problems of natural destruction such as deforestation and social problems such as waste disposal. Is causing. In order to deal with these problems, it is strongly demanded to reduce the consumption amount of the recording medium such as reproduction of recording paper. In response to this problem, a recording medium that can be repeatedly recorded and erased has recently attracted attention.

Therefore, as a recording medium having such characteristics, there has been proposed a recording medium capable of reversibly changing both the transparent state and the cloudy state depending on the temperature applied to the recording material (for example, JP-A-55-154198). (See the official gazette).

In the transparent state, when the temperature is raised from T1 to T3, the recording medium changes from the transparent state to the cloudy state, and even when the temperature returns to T1, the cloudy state is maintained as it is. Then, when the temperature of the recording medium is raised from T1 to T2 and returned to T1 again, the cloudy state is changed to the transparent state, and the transparent state is maintained as it is. This change can be repeatedly reproduced.

As described above, the recording apparatus using the recording medium capable of repeatedly recording and erasing solves the problems of the conventional recording apparatus. In particular, a recording medium made of a low molecular weight / polymer composite film recording material that repeatedly shows both cloudy and transparent states due to the temperature history as described above can be recorded and erased by a thermal head that is widely used in conventional thermal recording means. It is an excellent material that can be used.

[0007]

In thermal recording by a thermal head, Joule heat is generally generated in a heating resistor of the thermal head in a time of the order of [ms]. As described above, since the time is extremely short, the temperature of the central portion of the heating resistor becomes higher than that of the peripheral portion. This temperature distribution is also reflected in the contact area (generally an image point) of the recording medium with the heating resistor, and the temperature of the central portion of the image point forming area of the recording medium is higher than that of the peripheral portion. The temperature difference between the central part and the peripheral part becomes larger as the recording speed becomes faster and the heating resistor is driven with a larger electric power in a shorter time.

On the other hand, when recording is performed on a recording medium that shows a change in state that can be visualized due to different temperature histories, such as the above-described low molecular weight / polymer composite film recording material, the temperature at the center of the image point of the recording medium When the heating resistor is heated to reach the clouding temperature, the peripheral part does not reach the clouding temperature, so the clouding does not occur, and there is a problem that a cloudy image point corresponding to the size of the desired image point cannot be obtained. is there.

Further, when the heating resistor is heated so that the temperature of the peripheral portion becomes the clouding temperature, the peripheral portion also becomes cloudy,
Although a cloudy image point corresponding to a desired image point size can be obtained, there is a problem that the durability of repeated recording deteriorates for the reason described below.

Therefore, according to the present invention, image recording and erasing corresponding to the size of the heating element of the thermal recording means can be performed, and
An object of the present invention is to provide a recording apparatus capable of improving the durability of repeated recording on a recording medium.

[0011]

The recording apparatus of the present invention uses a thermal recording means to record or erase a visible image on a recording medium showing two states of recording and erasing due to thermal history of different temperatures. In the recording apparatus for performing the above, the visible image is recorded or erased by heating one image point forming region, which is a recording unit of the visible image of the recording medium, with a plurality of hot spots.

Further, the recording apparatus of the present invention is a recording apparatus for recording or erasing a visible image using a thermal recording means on a recording medium showing two states of recording and erasing due to thermal history of different temperatures. In order to record or erase a visible image on a recording medium using a thermal recording means having a heating element that generates a plurality of hot spots corresponding to one image point forming area which is a recording unit of the visible image. Characterize.

[0013]

According to the present invention, when a visible image is recorded on a recording medium, the areas of the recording medium corresponding to the size of the heating element of the thermal recording means are divided as if they were heated. Therefore, the peripheral portion of the area of the recording medium corresponding to the size of the heating element, that is, the image spot size can be heated without changing from the central portion. Therefore, it is possible to perform image point recording and erasing corresponding to the size of the heating element of the thermal recording means, and to improve the durability of repeated recording on the recording medium.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 schematically shows the structure of the recording apparatus according to this embodiment. In the figure, 11 is a CPU
(Central processing unit) controls the entire device. Reference numeral 12 denotes a thermal head as a thermal recording means, which applies thermal energy for recording or erasing a visible image to a recording medium described later, and is arranged in a line in a direction orthogonal to the conveying direction of the recording medium. It has a large number of heating resistors (heating elements). Reference numeral 13 denotes a thermal head drive circuit, which controls energization of the heating resistor of the thermal head 12.

Reference numeral 14 is an energization time arithmetic circuit, which is a recording energy for the mark dot data corresponding to the image formation information of the recording image data, and an erase operation for the space dot data corresponding to the non-image formation information of the recording image data. Each energy is calculated.

A conveying motor 15 drives a conveying roller for conveying the recording medium and a conveying means such as a platen.
16 is a motor drive circuit for driving the carry motor 15, 17
Is a motor control circuit for controlling the carry motor 15, 18 is a detector for detecting the position of a print medium to be carried, 19 is a character generator, 20 is RAM (random access memory), and 21 is ROM (read only read). Memory).

The recording medium used in this example is a low molecular weight / polymer composite film recording material that repeatedly shows both cloudy and transparent states depending on the temperature history, and it is possible to repeatedly record and erase a visible image. For example, it is configured as shown in FIG. That is, the recording medium is the base material 31.
A colored layer 32 colored in black or the like, a recording layer 33 reversibly showing two states of transparent and opaque, and a protective layer 34 are sequentially laminated on one surface.

The recording layer 33 has, for example, temperature-whitening / transparency characteristics as shown in FIG. That is, in the transparent state, when the temperature is increased from T1 to T3, the transparent state becomes a cloudy state, and even when the temperature returns to T1, the cloudy state is maintained as it is. Then, when the temperature of the recording medium is raised from T1 to T2 and returned to T1 again, the cloudy state is changed to the transparent state, and the transparent state is maintained as it is. This change can be repeatedly reproduced.

Recording of a visible image on such a recording medium is performed by selectively making the recording layer 33 cloudy with the recording layer 33 being transparent and the colored layer 32 being a base color, and then being erased. Is done by making the cloudy image transparent. The recording layer 33 used here is about 60
C. to about 90.degree. C., and the turbidity becomes saturated at about 95.degree. Moreover, the upper limit of the heating temperature is determined by the heat resistance of the protective layer 34 or the recording layer 33. About 1 for this recording medium
It was 80 ° C.

Recording is started when the recording medium is conveyed, the leading end of the recording medium is detected by the detector 18, and the predetermined position comes to the position of the heating resistor of the thermal head 12. First, under the control of the CPU 11, print image data corresponding to a print image to be printed is generated. The recorded image data is code data, and the code data is converted into bit data by the character generator 19 and then the RAM 2
Stored in 0.

After the code data is converted into bit data, the bit data is sequentially read from the RAM 20 by a recording command from the CPU 11. The energization time of the read bit data is determined by the energization time calculation circuit 14. The thermal head drive circuit 13 selectively drives the heating resistors of the thermal head 12 to generate heat in accordance with the determined energization time, thereby recording a visible image on the recording medium and performing unnecessary recording. It is designed to erase the visual image.

FIG. 2 schematically shows a heating resistor of the thermal head 12. That is, one heating resistor 4
Reference numeral 1 has a one-to-one correspondence with one image point (dot) which is a recording unit of a visible image to be recorded, and is formed in a rectangular shape, for example. The heat generating resistor 41 has non-heat generating portions 42, 42 formed vertically adjacent to each other in substantially the center of the horizontal direction thereof, and also has non-heat generating portions 42, 42 on both sides corresponding to the non-heat generating portions 42, 42, respectively. The heat generating parts 43, ... Are formed.

Reference numeral 44 is an individual electrode for each heating resistor 41, and 45 is a common electrode common to each heating resistor 41. A thermal head having a heating resistor having such a shape is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-230959.

In the heating resistor 41 having such a shape, four bottleneck paths 46, ... Are formed in the heating resistor 41. As a result, when a current flows between both electrodes 44 and 45,
Since the current density is high in the bottleneck 46, ... Of the location, a larger amount of Joule heat is generated than in other locations. Therefore, four high temperature parts (hot spots) are formed in the heating resistor 41.

Next, the rewriting / recording operation of the visible image in such a structure will be described with reference to FIG. The example of FIG. 6 shows an example in which the character “L” is overwritten on the character “I”. First of all,
As shown in FIG. 6A, the character "I" is recorded on the recording medium, and as shown in FIG.
When rewriting and recording the character of, the process of FIG. 6B is performed.

That is, the recording medium 1 as shown in FIG.
The heating resistor array 2 of the thermal head 12 (a large number of heating resistors 41 shown in FIG. 2 are arranged in a row) 2 is in contact with the heating head array 2 of the recording medium 1. It is arranged orthogonal to the transport direction (recording direction). In addition,
The heating resistors are provided in a sufficient number to record the width of the recording medium 1.

In FIG. 6, 3 is a part of the old image "I" which has already been recorded, 4 is a part of the new image "L" which is currently recorded, 5 is a part of the erased image "I", 6 Is the re-recorded image point portion. When recording on the recording medium 1, it suffices to raise the heating resistor corresponding to the target image point (mark dot) to a temperature at which the recording medium 1 rises to the cloudy temperature range regardless of the existing image. Also, when erasing, the heating resistor corresponding to the target image point (space dot) may be raised to a temperature at which the recording medium 1 rises to the transparent temperature range regardless of the already-existing image.

The thermal head 1 fixed in this way
The rewritable recording (overwriting) in which a new image 4 is recorded and at the same time the old image 3 is erased by selectively heating the heating resistor while the recording medium 1 is conveyed in the direction of the arrow under the heating resistor array 2 of 2 Write recording) is performed.

Next, the heating operation of the heating resistor 41 of the thermal head 12 to the recording medium will be described with reference to FIG. FIG. 1 shows the temperature distribution of an exothermic resistor 41 measured by an infrared thermometer, and its temperature distribution is schematically shown by an isotherm. FIG. 1A shows the thermal head 1 according to the present embodiment.
2 shows a case of the heating resistor 41 having a plurality of hot points, and FIG. 7B shows a case of a heating resistor having one hot point of the conventional thermal head as a comparative example. In order to make the maximum temperature the same, in this embodiment, 0.3
Each heating resistor was driven at 0 mJ / dot and conventionally at 0.25 mJ / dot.

From FIG. 1A, in this embodiment, four high temperature parts (hot spots) H1 and H4 which are independent in the heating resistor 41 are provided.
It can be seen that there are 2, H3 and H4. Further, it is possible that the bottom portions of the temperature distribution due to the four high temperature portions H1, H2, H3, H4 overlap and complement each other, resulting in a state where the temperature difference is small as a whole. When the recording medium is recorded and heated by the heating resistor 41, the area of the recording medium corresponding to the size of the heating resistor 41 is heated all over,
In addition, it can be expected that the region is heated without a large temperature difference.

On the other hand, as shown in FIG. 1B, in the heating resistor of the conventional thermal head, there is a maximum temperature region only in a very small area in the center portion thereof, and the temperature suddenly increases toward the peripheral portion. It is falling.

The recording apparatus of the present embodiment, in which the difference in heat generation temperature inside the heat generating resistor is relatively small, is advantageous when recording on a recording medium that repeatedly shows two visible states at different history temperatures. That is, since the change in the state of the recording medium depends on the maximum history temperature, it is necessary to make the temperature of the image forming region of the recording medium uniform in image forming and image erasing. Conventionally, there is a maximum temperature range only in a very small area in the center of the heating resistor.Therefore, controlling the temperature of this area to the temperature range of clouding or transparency reduces the area where clouding or transparency can occur. , Which is smaller than the size of the image point to be originally formed. On the other hand, in this embodiment, since the maximum temperature range is widened, it is possible to form and erase the image points corresponding to the size of the image points to be formed.

For the following reason, the recording apparatus of this embodiment has a relatively small difference in heat generation temperature within the heat generating resistor.
The durability of repeated recording on the recording medium can be significantly improved.

That is, the present inventors investigated the relationship between the clouding temperature and the repeated recording durability of the cloudy image, and FIG.
We obtained the findings shown in. For example, a transparent recording medium as an initial state is heated by a heat roller rotating at a peripheral speed of 40 mm / s at a constant temperature to measure the image density, and this is repeated to change the image density with respect to the number of repetitions. Was measured. As the temperature of the heat roller, TW1, TW2 and TW3 in the cloudy saturation temperature range shown in FIG. 8 were used.

As is clear from FIG. 7, as the clouding temperature becomes higher, the cloudy density changes more as the number of repetitions increases. Therefore, the durability at repeated recording is improved as the recording is performed at a lower temperature which is sufficient to obtain the required density.

In the conventional device, as shown in FIG. 1 (b), even if the heat-generating temperature of the heat-generating resistor becomes cloudy or transparent, the temperature difference between the respective parts in that temperature range is large. That is, it indicates that there is a high possibility that the deterioration will partially occur quickly. On the other hand, in the present embodiment, the temperature difference between the respective parts in the temperature range where clouding or transparency can occur is small, and the durability can be improved by controlling the temperature.

Next, another embodiment of the present invention, in which the laser thermal recording means is used as the thermal recording means, is shown in FIG.
Will be described. In FIG. 9, reference numeral 51 is a semiconductor laser oscillator that generates double beam light, 52 is a collimator lens, 53 is a cylindrical lens, 54 is a polygon mirror, 55 is an fθ lens, 56 is a cylindrical lens, and 57 is shown in FIG. The recording medium is as shown.

The laser beam light modulated according to the recording image data output from the semiconductor laser oscillator 51 is deflected by the rotation of the polygon mirror 54, and dot-sequentially scans the recording medium 57. The laser beam light irradiating the recording layer 33 of the recording medium 57 is photo-thermally converted to generate heat according to the amount of the irradiated laser beam light, and the recording layer 33 is heated and its temperature becomes cloudy. Set the temperature to clear or clear.

The heating operation of the recording medium 57 in this embodiment will be described with reference to FIG. In FIG.
A square shown by a broken line indicates one image point (dot). FIG. 7A schematically shows the image spot forming operation by the double beam light of this embodiment and the temperature distribution on the recording medium at that time, and FIG. 9B shows a conventional single beam as a comparative example. The image forming operation by light and the temperature distribution on the recording medium at that time are schematically shown.

In this embodiment, as shown in FIG. 10, two elliptical spots S that are vertically adjacent to each other by the double beam light are used.
1 and S2 are scanned in the arrow direction to irradiate the recording medium 57 in a dot shape. At that time, in the irradiated recording medium 57, the absorbed light is converted into heat, and the heat raises the temperature distribution A as shown in the figure. Conventionally, the recording medium is similarly irradiated in a dot shape with a single spot, and the temperature distribution of the heated recording medium at this time becomes a temperature distribution B as shown in the figure. Each of the temperature distributions shows the temperature distribution of the position cross section in the direction orthogonal to the scanning direction of the light beam, and the broken line in the temperature distribution shows the cloudy temperature region.

According to this embodiment, the temperature difference between the respective portions of the recording medium in the cloudy temperature region is relatively small, and the hot spots generated by the irradiation of the beam light are heated so as to divide the image spot forming region of the recording medium. Therefore, the image points as designed are formed.

On the other hand, in the conventional apparatus, in order to form the image points as designed, as can be understood from the figure, the temperature difference between the respective portions of the recording medium in the cloudy temperature region becomes large, and as described above. In addition, the repeated recording durability of the recording medium deteriorates. If the maximum cloudiness temperature is lowered, the image points formed become smaller than the designed value, and good image quality cannot be obtained.

In the above embodiment, the white turbid state of the recording layer is used as the recorded image, but the white turbid state may be used as the background color and the transparent state may be used as the recorded image. Further, the recording material to which the present invention can be applied is not limited to the materials of the above-mentioned examples, and can also be applied to a recording material using a leuco dye that exhibits a reversible color tone change only by controlling thermal energy as a color source.

[0045]

As described above in detail, according to the present invention, when a visible image is recorded on a recording medium, the area of the recording medium corresponding to the size of the heating element of the thermal recording means is divided as if each area was divided. Since the divided areas can be heated like heating, the peripheral portion of the area of the recording medium corresponding to the size of the heating element, that is, the image point size, can be heated without changing from the central portion. It is possible to provide a recording apparatus capable of performing image point recording and erasing corresponding to the size of a body and improving durability of repeated recording on a recording medium.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a heating operation of a recording medium of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a heating resistor of a thermal head.

FIG. 3 is a block diagram schematically showing a recording device.

FIG. 4 is a vertical sectional side view showing the configuration of a recording medium.

FIG. 5 is a diagram for explaining a state of a recording material that can be changed to both a cloudy state and a transparent state depending on a history temperature.

FIG. 6 is a diagram for explaining a rewrite recording operation.

FIG. 7 is a diagram showing changes in white turbidity concentration with repeated white turbidity.

FIG. 8 is a diagram for explaining transition temperature ranges of both cloudy and transparent states.

FIG. 9 is a diagram schematically showing a configuration of laser thermal recording means in another embodiment of the present invention.

FIG. 10 is a diagram for explaining a heating operation for a recording medium.

[Explanation of symbols]

1, 57 ... Recording medium, 2 ... Heating resistor array, 11 ...
CPU, 12 ... Thermal head (thermal recording means), 13
...... Thermal head drive circuit, 14 ...... Energization time calculation circuit, 31 ...... Substrate, 32 ...... Colored layer, 33 ...... Recording layer,
34: protective layer, 41: heating resistor (heating element), 4
2, 43 ... Non-heating part, 44 ... Individual electrode, 45 ... Common electrode, 46 ... Bottle, H1 to H4 ... High temperature part (hot spot).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41M 5/36 8305-2H B41M 5/26 102

Claims (2)

[Claims] 1. A recording apparatus for recording or erasing a visible image by using a thermal recording means on a recording medium showing two states of recording and erasing by thermal history of different temperatures. A recording apparatus which records or erases a visible image by heating one image point forming region, which is a recording unit of a visible image, with a plurality of hot spots. 2. A recording apparatus for recording or erasing a visible image using a thermal recording means on a recording medium showing two states of recording and erasing by thermal history of different temperatures. A recording apparatus for recording or erasing a visible image on a recording medium by using a thermal recording unit having a heating element that generates a plurality of hot spots corresponding to one image point forming area which is a recording unit.