JP2567516B2 - Color thermal recording device - Google Patents

Description

The present invention relates to a color thermosensitive recording device.

[Conventional technology]

The thermal recording device includes a thermal recording device and a thermal transfer recording device. Among them, the thermal recording device can directly record an image directly on the thermal recording material, so that waste such as a transfer sheet is not generated. Moreover, it has features such as simple structure. Due to such characteristics, the thermal recording apparatus tends to be widely used, and for example, most of facsimiles have a monochrome thermal recording apparatus incorporated therein. Recently, for example, as described in JP-A-61-213169, a magenta thermosensitive coloring layer, a cyan thermosensitive coloring layer, and a yellow thermosensitive coloring layer are sequentially formed on a support to form a full-color image. A color thermal recording material has been proposed which enables direct thermal recording.

Further, Japanese Patent Laid-Open No. 61-213169 describes a color thermosensitive recording apparatus for recording a color image on a color thermosensitive recording material. In this color thermal recording apparatus, an optical fixing device including a light source and a three-color filter is arranged on the downstream side of the thermal head. At the time of thermal recording, the platen drum equipped with the color thermosensitive recording material is rotated in the forward direction to record a yellow image on the yellow thermosensitive coloring layer with the thermal head, and the light from the light source is passed through the yellow filter to the part where the yellow image is recorded. To heat-fix the yellow thermosensitive coloring layer. Next, the platen drum is reversely rotated to return the color thermosensitive recording material to the recording start position, and then the cyan image is recorded on the cyan thermosensitive recording layer by the thermal head while the platen drum is normally rotated. At the same time, the light from the light source is applied to the portion where the cyan image is recorded through the cyan filter to optically fix the cyan thermosensitive coloring layer. After reversing the platen drum to return the color thermosensitive recording material to the initial position, while rotating the platen drum forward, the magenta image is recorded on the magenta thermosensitive coloring layer with the thermal head, and then the image is fixed with light using the magenta filter. .

[Problems to be Solved by the Invention]

In the above-described color thermal recording apparatus, the thermal head and the optical fixing device are separate bodies, so that there is a problem that assembly is troublesome and a large installation space is required. Further, since three-color images are recorded in two and a half round trips, there is a problem that it takes time to record.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color thermal recording apparatus which is easy to assemble and can be installed in a narrow space by uniting a thermal head and an optical fixing device.

Another object of the present invention is to provide a color thermal recording apparatus capable of recording a color image in one and a half round trips.

[Means for solving the problem]

In order to achieve the above object, in the invention described in claim (1), a thermal head for applying heat energy to each thermosensitive coloring layer, and first and second lights mounted on both sides of the thermal head. A guide, a first electromagnetic wave generation source for irradiating electromagnetic waves to the third thermosensitive coloring layer via the first light guide, and an electromagnetic wave to the second thermosensitive coloring layer via the second light guide. And a second electromagnetic wave generation source.

In the invention described in claim (2), a thermal head for applying heat energy to each thermosensitive coloring layer, first and second light guides attached to both sides of the thermal head, and the first light A first electromagnetic wave generation source for irradiating the third thermosensitive coloring layer with an electromagnetic wave via a guide; and a second electromagnetic wave generation source for irradiating the second thermosensitive coloring layer with an electromagnetic wave via a second light guide, First and second conveyor belt mechanisms disposed on the left and right of the thermal head for nipping and conveying the color thermosensitive recording material, and the color thermosensitive recording material is reciprocated by one and a half times when recording a color image, A transport control unit for controlling the driving of the first and second transport belt mechanisms is provided.

[Action]

In the invention described in claim (1), since the light guides are fixed to both sides of the thermal head and these are unitized as a recording head, the assembly is simplified and the recording head can be incorporated in a narrow space.

In the invention described in claim (2), the unitized recording head is used, and the first and second conveyor belt mechanisms are arranged on both sides of the recording head, so that when the color image is recorded, these conveyor belt mechanisms are used to perform the color heat-sensing. The recording material is made to reciprocate once and a half, and image recording is performed during these three movements.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2, a recording head 10 includes a thermal head 11 and a pair of heat dissipation plates 12 and 1 fixed to both sides of the thermal head 11.
3 and a pair of light guides fixed to the heat sinks 12 and 13
It is composed of 14 and 15, and is unitized to facilitate assembly. The thermal head 11 has a plate shape extending in a direction (main scanning direction) orthogonal to the moving direction (sub-scanning direction) of the color thermosensitive recording material 16 so that the recording surface contacts the color thermosensitive recording material 16. Are arranged vertically. On this recording surface, a plurality of heating elements are arranged in a line along the sub-scanning direction. Each heating element generates thermal energy according to the color and density to be recorded, and thermally records a plurality of pixels on the color thermosensitive recording material 16.

The heat dissipation plates 12 and 13 are arranged on both sides of the thermal head 11 to prevent the thermal head 11 from accumulating heat. These heat dissipation plates 12 and 13 are made of a metal plate having excellent heat dissipation,
Further, a plurality of holes 17 extending in the main scanning direction are formed in order to enhance heat dissipation.

The light guides 14 and 15 are electromagnetic waves for performing optical fixing,
For example, it is made of a material having a high transmittance for near-ultraviolet rays and ultraviolet rays, for example, transparent glass or transparent acrylic, and its emission ends 14a, 15a are flush with the recording surface of the thermal head 11. Further, arc-shaped recesses 14b and 15b are formed at the incident ends of the light guides 14 and 15, and the rod-shaped ultraviolet lamps 20 and 21 extending in the main scanning direction are partially inserted in the recesses 14b and 15b. It is arranged. The ultraviolet lamp 20 generates ultraviolet rays having a peak wavelength of 365 nm, and the ultraviolet lamp 21 generates near ultraviolet rays (blue-violet light) having a peak wavelength of 420 nm. The mirrors 22 and 23 are used to utilize the electromagnetic waves emitted to the back of these ultraviolet lamps 20 and 21. Note that the reference numeral 2
4 is a thermal head driver.

A platen roller 26 is arranged below the recording head 10. A paper feed side transport belt mechanism 27 and a paper discharge side transport belt mechanism 28 are arranged on the left and right of the platen roller 26, respectively. The paper feed side transport belt mechanism 27 is composed of an upper belt 29 and a lower belt 30, and transports the color thermosensitive recording material 16 between them. The upper belt 29 is hung on the pair of rollers 31, 32, and the lower belt 30 is hung on the pair of rollers 33, 34. As the upper belt 29 and the lower belt 30, one wide belt is used, and a plurality of narrow belt-shaped belts, for example, two belts are used to fix both sides of the color thermosensitive recording material 16. It may be sandwiched. Since the paper discharge side transport belt mechanism 28 has the same structure as the paper feed side transport belt mechanism 27, only the reference numerals are given and the description thereof is omitted.

The head control unit 45 outputs the image signal input from the image signal input unit 46 of the TV camera, the video player, the scanner, etc.
Read line by line and use this for the thermal head driver
Send to 24. The thermal head driver 24 controls the amount of heat generated by each heating element according to each image signal, and thermally records the color thermosensitive recording material 16. The lamp control unit 47 causes the ultraviolet lamp 20 to emit light during thermal recording of a magenta image, and causes the ultraviolet lamp 21 to emit during thermal recording of a yellow image. The pulse motor 49 includes a platen roller 26, a conveyor belt mechanism 27,
The drive controller 49 controls the amount of rotation and the direction of rotation. The controller 50
The head controller 45, the lamp controller 47, and the transport controller 48 are sequence-controlled.

FIG. 3 shows an example of a color thermosensitive recording material. A cyan thermosensitive coloring layer 56, a magenta thermosensitive coloring layer 57, a yellow thermosensitive coloring layer 58, and a protective layer 59 are sequentially formed on the support 55. These thermosensitive coloring layers 56 to 58 are layered from the surface in the order of thermal recording. For example, in the case of thermal recording in the order of magenta, yellow, and cyan, the yellow thermosensitive coloring layer and the magenta thermosensitive coloring layer. The positions of the layers are exchanged.

An opaque coated paper or a plastic film is used as the support 55, and a transparent plastic film is used when an OHP sheet is prepared. The cyan thermosensitive coloring layer 56 contains an electron-donating dye precursor and an electron-accepting compound as main components, and develops a cyan color when heated. The magenta thermosensitive coloring layer 57 contains a diazonium salt compound having a maximum absorption wavelength of 360 ± 20 nm, and a coupler that thermally reacts with this compound to develop magenta. This magenta thermosensitive coloring layer 57 is a thermal head.
After thermally recording the magenta image in 11, when the ultraviolet light of 360 ± 20 nm is irradiated, the diazonium salt compound is photolyzed and the coloring ability is lost. The yellow thermosensitive coloring layer 58 contains a diazonium salt compound having a maximum respiration wavelength of 420 ± 20 nm, and a coupler that thermally reacts with this compound to develop yellow. This yellow thermosensitive coloring layer 58 is also photo-fixed when irradiated with near-ultraviolet rays in the vicinity of 420 nm ± 20 nm and loses its coloring ability.
The color thermosensitive recording material is described in detail in Japanese Patent Application No. 2-89384 filed by the present applicant on April 4, 1990.

FIG. 4 shows the characteristics of the thermosensitive coloring layers 56 to 58. The heat energy on the horizontal axis represents the heat energy generated by the heating element of the thermal head 11, and the heat energy of the yellow thermosensitive coloring layer 58 is the lowest and the heat energy of the cyan thermosensitive coloring layer is the lowest.
56 has the highest thermal energy. The main reason for this difference in thermal energy is that the cyan thermosensitive coloring layer 56 must be heated via the yellow thermosensitive coloring layer 58 and the magenta thermosensitive coloring layer 57.

FIG. 5 shows the absorption characteristics of the yellow thermosensitive coloring layer 58 and the emission characteristics of the ultraviolet lamp 21. As shown by the dotted line, the yellow thermosensitive coloring layer 58 has a light absorbing property in the range of approximately 300 nm to 450 nm, and when irradiated with ultraviolet rays in this range,
The diazonium salt compound decomposes and photofixes. Therefore,
The UV lamp 21 is 420 nm, as indicated by the hatching 62.
Has maximum emission energy.

FIG. 6 shows the absorption characteristics of the magenta thermosensitive coloring layer 57 and the emission characteristics of the ultraviolet lamp 20. The magenta thermosensitive coloring layer 57 has a light absorbing property in a range of approximately 300 nm to 400 nm as shown by a dotted line. Therefore, the ultraviolet lamp 20 for optically fixing the magenta has 36% as shown by the hatching 63.
The maximum emission energy is 5 nm.

In this way, the magenta thermosensitive coloring layer 57 and the yellow thermosensitive coloring layer 58 are shifted in absorption wavelength range so that they are not simultaneously fixed by light, but this absorption wavelength range is considered in consideration of characteristics of ambient light and a fixing lamp. I can decide. Further, the cyan thermosensitive coloring layer 56 has a high value such that the coloring heat energy does not exist in a normal storage state, and thus is not provided with optical fixing property. If necessary, the cyan thermosensitive coloring layer is composed of a diazonium salt compound which gives an absorption wavelength region deviating from the absorption wavelength regions of the two thermosensitive coloring layers 57 and 58, and a coupler capable of coloring cyan. May be.

Next, the operation of the above embodiment will be described. When the controller 50 is instructed to perform thermal recording, the pulse motor 49 is rotated in the forward direction to drive the paper feed side conveyance belt mechanism 27, the paper ejection side conveyance belt mechanism 28, and the platen roller 26, and from the paper feed side to the paper ejection side. Paper feed. The color thermosensitive recording material 16 is fed from the cassette one by one, or pulled out from a roll of the color thermosensitive recording material and cut into a sheet. The sheet-shaped color thermosensitive recording material 16 is sandwiched between the conveyor belts 29 and 30 from the rollers 31 and 33 side and conveyed toward the recording head 10. During this transportation, the color thermosensitive recording material
16 tip parts are sent out from the paper feed side conveyor belt mechanism 27,
It passes between the recording head 10 and the platen roller 26, and is inserted into the paper discharge side transport belt mechanism 28.

While the color thermosensitive recording material 16 is being conveyed, when the tip of the recording area reaches the thermal recording position, thermal recording of the yellow image is started. First, the head control unit 45 reads out the image signal for one line of the yellow image from the image signal input unit 46. These image signals are converted into drive signals in consideration of the coloring characteristics shown in FIG. These drive signals are sent to the thermal head 11 and supplied to the corresponding heating elements, and each heating element generates thermal energy corresponding to the density to be recorded. As a result, the first line of the yellow image is thermally recorded on the yellow thermosensitive coloring layer 58. When the recording of the first line is completed, the drive signal of the second line of the yellow image is sent to the thermal head 11, and the second line is thermally recorded on the yellow thermosensitive recording layer 58. By repeating these operations, the yellow image is thermally recorded line by line.

At the time of thermal recording of the yellow image, the ultraviolet lamp 21 is turned on to generate near ultraviolet rays in the vicinity of 420 nm. This near-ultraviolet ray is emitted from the emission end 15a thereof through the light guide 15, and the color thermosensitive recording material 16 on which the yellow image is thermally recorded.
Is irradiated to the part. With this near-ultraviolet light of 420 nm,
The diazonium salt compound contained in the yellow thermosensitive coloring layer 58 is decomposed to eliminate the coloring ability.

After the yellow image has been recorded, the UV lamp 21
Is turned off and the ultraviolet lamp 20 is turned on. Along with this, the pulse motor 49 is rotated in the reverse direction, and the paper feed side transport belt mechanism 27, the paper discharge side transport belt mechanism 28, and the platen roller.
26 is driven and the paper is fed from the paper discharge side to the paper feed side.
In the returning process of the color thermosensitive recording material 16, the thermal head 11 forms a magenta image on the magenta thermosensitive coloring layer 57.
Heat record line by line. When the portion on which the magenta image is thermally recorded reaches the exit end 14a of the light guide 14, it is irradiated with 365 nm ultraviolet rays generated from the ultraviolet lamp 20 to perform optical fixing. During thermal recording of this magenta image, as shown in FIG. 4, it is approximately 40 to 70 mJ / mm ²
The thermal energy within the range and depending on the density to be recorded is used. The heat energy in this range is sufficient to record the yellow thermosensitive coloring layer 58, but since the yellow thermosensitive coloring layer 58 has already been optically fixed, the yellow thermosensitive coloring layer 58 does not develop color.

After the recording of the magenta image, the pulse motor 49 rotates in the normal direction again, so that the color thermosensitive recording material 16 is conveyed from the paper feeding side to the discharging side. When the color thermosensitive recording material 16 is conveyed, the thermal head 11 thermally records a cyan image on the cyan thermosensitive coloring layer 56 line by line. At the time of thermal recording of the cyan image, both the ultraviolet lamps 20 and 21 are turned off, and optical fixing is not performed.

Since the pulse motor 49 continues to rotate after recording the cyan image, the color thermal recording sheet 16 on which the three-color sequential thermal recording has been performed is ejected to the tray (not shown) via the paper ejection side transport belt mechanism 36. To be done.

In the above-described embodiment, the recording of the color image is completed in the five steps of the paper feeding step, the yellow image thermal recording step, the magenta image thermal recording step, the cyan image thermal recording step, and the paper discharging step. Also, color thermosensitive recording materials
From the viewpoint of 16 transports, a color image is recorded in one and a half round trips. It should be noted that an ultraviolet lamp is used for thermal recording of yellow images.
21 is turned off, and instead, the ultraviolet lamp 21 is turned on during the thermal recording of the magenta image, the yellow thermosensitive coloring layer 58 is optically fixed immediately before the thermal recording of the magenta image, and the ultraviolet lamp 20 is applied during the thermal recording of the cyan image. May be turned on and the magenta thermosensitive coloring layer 57 may be optically fixed immediately before thermal recording of a cyan image.

FIG. 7 shows an embodiment in which the recording head is moved in the main scanning direction to record a color image. A pair of paper feed rollers 70, 71 are rotatably arranged with an appropriate interval, and a color thermosensitive recording material wrapped around the outer circumference of these.
Carry 73 in the direction of the arrow. These paper feed rollers 70,71
A horizontally long receiving plate 72 is arranged between the two, and the color thermosensitive recording material 73 can be kept flat.

The recording head 75 has heat sinks 7 on both sides of the thermal head 76.
7,78 are fixed, and light guides 79,80 are fixed next to them. The thermal head 76 has a plurality of heating elements arranged in a line in the sub-scanning direction, and simultaneously records a plurality of lines. As a ride guide 79, 80,
In order to make the recording head 75 movable, a flexible fiber bundle in which a large number of optical fibers are combined is used. In addition, the light guide 79, 80 incident end is almost 365
With an ultraviolet lamp 81 that emits ultraviolet rays in the wavelength range of nm,
An ultraviolet lamp 82 that emits near-ultraviolet rays of 420 nm is arranged.

The recording head 75 is fitted into the hole 84a of the mounting plate 84 so as to be flush with the mounting plate 84.
It is held by the carriage 85 via the. The carriage 85 is slidably attached to a prism-shaped guide 86, and moves in the main scanning direction along with the recording head 75 along the guide 86. A part of the toothed belt 87 is connected to the carriage 85. This toothed belt 87
It is applied to a gear 89 driven by a pulse motor 88.

When recording the color image, if the pulse motor 88 rotates forward, the gear 89 rotates clockwise and the carriage 85 guides.
Follow 86 and move to the right in FIG. The recording head 75 moves together with the carriage 85, and during this movement, the thermal head 76 simultaneously thermally records a plurality of lines of the yellow image. At the time of thermal recording of this yellow image, the ultraviolet lamp 82 is turned on to generate near ultraviolet rays in the vicinity of 420 nm. This near-ultraviolet ray is applied to the color thermosensitive recording material 73 through the light guide 80 to photofix the yellow thermosensitive coloring layer in the recorded portion.

When the recording head 75 reaches the right end, the pulse motor 88 switches to reverse rotation and rotates the gear 89 counterclockwise. As a result, the recording head 75 moves leftward together with the carriage 85. In the returning process of the recording head 75, the thermal head 76 simultaneously thermally records a plurality of lines of the magenta image. At the time of recording this magenta image, the ultraviolet lamp 81 is turned on to generate ultraviolet rays having a wavelength range of approximately 365 nm. This ultraviolet ray irradiates the color thermosensitive recording material 73 through the light guide 79, and optically fixes the magenta thermosensitive coloring layer in the portion where the magenta image is thermally recorded.

When the recording head 75 moves to the left end, the pulse motor 88 switches to normal rotation and rotates the gear 89 counterclockwise.
When the recording head 75 moves to the right, the thermal head
76 thermally records a cyan image on the cyan thermosensitive coloring layer. During the thermal recording of the cyan image, the ultraviolet lamps 81 and 82 are off.

When the recording head 75 reaches the right end, the pulse motor 88 switches to the reverse rotation and moves the recording head 75 toward the left end. Along with this, the paper feed rollers 70, 71 rotate in the direction of the arrow, and the color thermosensitive recording material 73 is moved by a constant pitch. This amount of movement corresponds to the length of the heating element array of the thermal head 76.

In this way, the reciprocation of the recording head 75 causes thermal recording of a plurality of lines of a three-color image on the color thermosensitive recording material 73. Thereafter, similarly, a color image is heat-recorded on the color heat-sensitive recording material 73.

〔The invention's effect〕

As described in detail above, according to the present invention, on both sides of the thermal head, the ride guides for irradiating the color thermosensitive recording material with electromagnetic waves are attached, and since these are unitized, the assembly is simplified and Can be installed in a small space. Further, according to the present invention, the conveyor belt mechanism is arranged on both sides of the unitized recording head, and the image recording is performed in both the forward process and the return process of the color thermosensitive recording material. A color image can be recorded in half, and therefore high-speed printing can be performed as compared with the conventional color thermal recording apparatus.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of the color thermosensitive recording apparatus of the present invention. FIG. 2 is a perspective view showing a main part of the embodiment shown in FIG. FIG. 3 is an explanatory diagram showing a layer structure of a color thermosensitive recording material. FIG. 4 is a graph showing the color forming characteristics of the color thermosensitive recording material. FIG. 5 is a graph showing the absorption characteristics of the yellow thermosensitive coloring layer and the spectral energy of the yellow fixing ultraviolet lamp. FIG. 6 is a graph showing the absorption characteristics of the magenta thermosensitive coloring layer and the spectral energy of the magenta fixing ultraviolet lamp. FIG. 7 is a perspective view of a main part showing another embodiment of the present invention in which the recording head is moved in the main scanning direction to perform thermal recording. 10 …… Recording head 11 …… Thermal head 14,15 …… Light guide 16 …… Color thermal recording material 20,21 …… UV lamp 27,28 …… Conveyor belt mechanism 73 …… Color thermal recording material 75 …… Recording Head 76 …… Thermal head 79,80 …… Light guide 81,82 …… UV lamp.

Claims (2)

(57) [Claims] 1. A first to third at least three heat-sensitive color developing layers having different colors and different heat energies are sequentially laminated on a support, and at least the second and third heat-sensitive color developing layers are unique. In a color thermosensitive recording device for recording a color image on the color thermosensitive recording material using a color thermosensitive recording material having light fixing property by electromagnetic waves, a thermal head for applying thermal energy to each thermosensitive coloring layer, and a thermal head First and second light guides attached to both sides of the head, and first electromagnetic wave irradiating the third thermosensitive coloring layer through the first light guides.
And a second electromagnetic wave generation source for irradiating the second thermosensitive coloring layer with an electromagnetic wave via a second light guide. 2. A support is provided with at least three first to third at least three heat-sensitive color developing layers having different colors and different heat energies, and at least the second and third heat-sensitive color developing layers are unique. In a color thermosensitive recording device for recording a color image on the color thermosensitive recording material using a color thermosensitive recording material having light fixing property by electromagnetic waves, a thermal head for applying thermal energy to each thermosensitive coloring layer, and a thermal head First and second light guides attached to both sides of the head, and first electromagnetic wave irradiating the third thermosensitive coloring layer through the first light guides.
And a second electromagnetic wave generation source for irradiating the second thermosensitive coloring layer with an electromagnetic wave through the second light guide,
First and second conveyor belt mechanisms disposed on the left and right of the thermal head for nipping and conveying the color thermosensitive recording material, and the color thermosensitive recording material is reciprocated by one and a half times when recording a color image, A color thermosensitive recording apparatus comprising: a conveyance control unit for controlling driving of the first and second conveyance belt mechanisms.