JPH05293980A - Thermal printer - Google Patents

Abstract

PURPOSE:To prevent an yellow band from remaining on the leading end part of the thermal recording material held by a clamp member. CONSTITUTION:A clamp member main body 14 is constituted of the transparent part 22 coming into contact with a thermal recording surface and the reinforcing part 21 reinforcing the transparent part 22. The reinforcing part 21 is constituted of a plurality of fin like metal plates 20. These fin like metal plates 20 are arranged so as to generate a gap with respect to the thermal recording surface in a state mutually separated along the irradiation direction of the electromagnetic beam from an optical fixing device. By this constitution, the unfixed part of a color thermal recording material 11 due to the shading of the clamp member can be eliminated. The clamp member can be constituted compactly with sufficient mechanical strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer,
More specifically, it relates to a thermal printer in which a portion pressed by a clamp member is also optically fixed.

[0002]

2. Description of the Related Art Thermal printers include thermal printers and thermal transfer printers. Of these, thermal printers are capable of directly thermal recording images on a thermal recording material, and therefore wastes such as ink ribbons and cassettes. It does not occur and has a simple structure. Because of these features, thermal printers are widely used. For example, most facsimiles incorporate monochrome thermal printers. Recently, for example, Japanese Patent Laid-Open No. 61-21316
As described in Japanese Patent Publication No. 9, a magenta thermosensitive coloring layer, a cyan thermosensitive coloring layer, and a yellow thermosensitive coloring layer are sequentially laminated on a support so that a full-color image can be directly heat-recorded. A color thermosensitive recording material has been proposed. With this color thermosensitive recording material, thermal recording is performed in order from the thermosensitive coloring layer on the surface, but at the time of heat recording on the next thermosensitive coloring layer, the thermosensitive coloring layer on which heat recording has already been performed is prevented from being thermally recorded again. Therefore, after the thermal recording, light having a wavelength range peculiar to each thermosensitive coloring layer is irradiated to lose the coloring ability.

[0003]

SUMMARY OF THE INVENTION In a printer, in order to mount a recording material on a holding member such as a platen drum,
A clamp member is widely used, and a part, for example, the leading end of the recording paper is pressed by the clamp member to prevent the recording paper from being displaced during the rotation of the platen drum. Incidentally, the color thermosensitive recording material is colored yellow by the diazonium salt compound used for the thermosensitive coloring layer, but becomes colorless when the diazonium salt compound is photolyzed by photofixation. However, since the tip portion pressed by the clamp member cannot be optically fixed, there arises a problem that a yellow band remains on the tip portion of the color thermosensitive recording material.

On the other hand, the clamp member may be made of a transparent member such as transparent plastic or glass. In this case, however, since the mechanical strength of plastic or glass is smaller than that of metal, the clamp member should be thickened. It is necessary to make the device thicker or thicker, which causes a new problem that the device configuration cannot be made compact.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal printer in a compact size in which a yellow band does not remain in a portion pressed by a clamp member.

[0006]

In order to achieve the above object, the present invention comprises a clamp member comprising a transparent member in contact with a heat-sensitive recording surface and a reinforcing portion for reinforcing the transparent member. Is arranged such that when the transparent member is in contact with the heat-sensitive recording material, the contact surface is irradiated with light from the optical fixing device.

Further, in the thermal printer according to the second aspect, the reinforcing portion is formed so that the lower portion has a V shape, and the transparent member is attached to the lower portion of the V shape.

Further, in the thermal printer according to the third aspect of the invention, the reinforcing portion is composed of a plurality of fin-shaped metal plates, and the direction of the fin-shaped metal plates is aligned with the irradiation direction of light from the optical fixing device. , Are arranged so that a gap is formed between them and the thermosensitive recording surface in a state where they are separated from each other.

Further, in the thermal printer according to the fourth aspect, the reinforcing portion is made of a metal member, and the transparent member is attached so as to project from the side portion of the reinforcing portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 2, a platen drum 10 holds a color thermosensitive recording material 11 on its outer periphery and is rotated by a pulse motor 9 during thermal recording and optical fixing. As shown in FIG. 3, at least one portion of the color thermosensitive recording material 11, for example, the tip portion 11a is pressed and fixed between the groove 10a of the platen drum 10 by the clamp member 13.

The clamp member 13 is a platen drum 10.
The clamp member main body 14 that fits into the groove 10a and the mounting arms 15 provided at both ends of the clamp member main body 14 are formed in a gate shape. An elongated hole 15a is formed in the mounting arm 15, and the mounting arm 15 is loosely fitted to the shaft 16 of the platen drum 10 through the elongated hole 15a. In addition, FIG.
As shown in, the mounting arm 15 is provided with a spring 17 and a solenoid 18. The spring 17
The mounting arm 15 is urged in the direction of fitting into the groove 10a. Further, the solenoid 18 is used for the color thermosensitive recording material 11
Is driven at the time of clamping and unclamping, so that the clamp member 13 is moved in the direction of coming out of the groove 10a.

As shown in FIG. 1, the clamp member main body 14
Is a reinforcing portion 21 composed of four fin-shaped metal plates 20,
It is composed of a transparent portion 22 made of acrylic resin or the like filled in the gap, and is arranged at the tip portion 15b of the mounting arm 15. The fin-shaped metal plates 20 are provided apart from each other, and are arranged in a direction perpendicular to the surface of the heat-sensitive recording material 11. Further, the lower end 20a of each fin-shaped metal plate 20 is covered with the transparent portion 22, which separates the fin-shaped metal plate 20 from the color heat-sensitive recording material 11, so that the light wraps around and the fixing light is blocked. Lost.

On the outer periphery of the platen drum 10, the thermal head 2 is provided at the thermal recording position of the color thermal recording material 11.
5. An optical fixing device 26 is provided downstream of the thermal recording. As is well known, the thermal head 25 has a large number of heating elements arranged in a line, and is heated to a temperature according to the color to be thermally recorded and its color density. The optical fixing device 26 has a capacity of about 365n as shown by the solid line in FIG.
m, a rod-shaped ultraviolet lamp 27 having an emission peak at 420 nm, and a cut filter 28 having a transmission characteristic shown by a dotted line. The cut filter 28 transmits near ultraviolet rays in the vicinity of 420 nm when it is placed in front of the ultraviolet lamp 27 by a driving device such as a solenoid.

As shown in FIG.
A pair of conveying rollers 31 is arranged, through which the color thermosensitive recording material 11 is conveyed. In addition, the paper feed / discharge path 3
On the platen drum 10 side of No. 0, a separation claw 32 is formed for guiding the rear end of the color thermosensitive recording material 11 to the paper feeding / discharging passage 30 during paper discharging. In this embodiment, one passage is used as both the paper feed passage and the paper discharge passage, but they may be provided separately.

FIG. 5 shows an example of the color thermosensitive recording material 11. On the support 35, a cyan thermosensitive coloring layer 36, a magenta thermosensitive coloring layer 37, a yellow thermosensitive coloring layer 3
8 and the protective layer 39 are sequentially layered. These thermosensitive coloring layers 36 to 38 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 intermediate layer is provided between the layers (not shown).

An opaque coated paper or a plastic film is used as the support 35, and a transparent plastic film is used when an OHP sheet is prepared. The cyan thermosensitive coloring layer 36 contains an electron-donating dye precursor and an electron-accepting compound as main components, and develops cyan when heated. Magenta thermosensitive coloring layer 3
No. 7 contains a diazonium salt compound having a maximum absorption wavelength of about 365 nm and a coupler which thermally reacts with this compound to develop magenta color. The magenta thermosensitive coloring layer 37 loses its coloring ability due to photolysis of the diazonium salt compound when ultraviolet rays in the vicinity of 365 nm are irradiated after the magenta image is thermally recorded by the thermal head 25.

The yellow thermosensitive coloring layer 38 contains a diazonium salt compound having a maximum absorption wavelength of about 420 nm and a coupler which thermally reacts with the diazonium salt compound to develop yellow. The yellow thermosensitive coloring layer 38 also undergoes photolysis when irradiated with near-ultraviolet rays in the vicinity of 420 nm and loses its coloring ability.
Since the magenta thermosensitive coloring layer 37 and the yellow thermosensitive coloring layer 38 contain a diazonium salt compound, the color thermosensitive recording material 11 is originally yellow. When these thermosensitive coloring layers 37 and 38 are optically fixed,
The color thermosensitive recording material 11 changes from yellow to colorless. The construction of this color thermosensitive recording material is described in JP-A-3-28.
No. 8688.

FIG. 6 shows the characteristics of the thermosensitive coloring layers 36 to 38. The thermal energy on the horizontal axis represents the thermal energy generated by the heating element of the thermal head 25, the thermal energy of the yellow thermosensitive coloring layer 38 is the lowest, and the thermal energy of the cyan thermosensitive coloring layer 36 is the highest.
The main cause of this difference in thermal energy is that the cyan thermosensitive coloring layer 36 must be heated via the yellow thermosensitive coloring layer 38 and the magenta thermosensitive coloring layer 37.

Next, the operation of this embodiment will be described. At the time of sheet feeding, the platen drum 10 is clamped by the clamp member 13 as shown in FIG.
At the paper feed position where it became almost vertical at. Further, the solenoid 18 is energized and the clamp member 13 is pulled out from the groove 10a. The conveying roller pair 31 is a color thermosensitive recording material 1 supplied from a cassette (not shown).
1 is nipped and conveyed toward the platen drum 10.
When the color thermosensitive recording material 11 is in the groove 10a of the platen drum 10, the pair of conveying rollers 31 is temporarily stopped.

After the color thermosensitive recording material 11 is set at the clamp position, the energization of the solenoid 18 is stopped. This causes the clamp member 13 to move to the spring 17
The color thermosensitive recording material 11 is clamped by the clamp member 13 because it is pulled back by. After this clamping, the platen drum 10 and the conveying roller pair 31 rotate, so that the color thermosensitive recording material 11 is transferred to the platen drum 10.
Is wrapped around the outer circumference of.

As the platen drum 10 rotates, the leading end of the recording area of the color thermosensitive recording material 11 reaches the thermal head 2.
When the number reaches 5, the yellow image is thermally recorded line by line by the thermal head 25. In the thermal recording of this yellow image, each heating element of the thermal head 25 is heated to a temperature in consideration of the color development characteristics shown in FIG. The portion on which the yellow image is thermally recorded reaches the optical fixing device 26, where optical fixing is performed. This optical fixing device 26 is
Since the cut filter 28 is set in front of the ultraviolet lamp 27, the near-ultraviolet light having a wavelength of about 420 nm is applied to the color thermosensitive recording material 11. Clamp member body 14
As shown in FIGS. 1 and 3, the reinforcing portion 21 and the transparent portion 2 are
2, the diazonium salt compound contained in the yellow thermosensitive coloring layer 38 is decomposed on the entire surface of the color thermosensitive recording material 11 including the tip portion 11a covered with the clamp member 13 to have a coloring ability. Will be lost.

When the platen drum 10 makes one rotation and the recording area reaches the position of the thermal head 25 again, a magenta image is thermally recorded on the magenta thermosensitive coloring layer 37 line by line. During thermal recording of magenta images, the cut filter 28 is retracted from the front of the ultraviolet lamp 27,
All the light emitted from the ultraviolet lamp 27 is applied to the portion of the color thermosensitive recording material 11 on which the magenta image is recorded. Of the light emitted from this ultraviolet lamp 27,
Magenta thermosensitive coloring layer 3 by ultraviolet rays around 365 nm
7 is optically fixed.

When the yellow thermosensitive coloring layer 38 and the magenta thermosensitive coloring layer 37 are optically fixed, the color thermosensitive recording material 1 is obtained.
1 changes from yellow to colorless. During thermal recording of the magenta image, as shown in FIG.
Thermal energy in the range of 70 mJ / mm ² and depending on the density to be recorded is used. The thermal energy in this range is higher than the thermal energy required to record the yellow thermosensitive coloring layer 38, but since the yellow thermosensitive coloring layer 38 has already been fixed by light, the yellow thermosensitive coloring layer 38 does not develop color. Absent.

When the platen drum 10 rotates once more,
Since the color thermosensitive recording material 11 faces the thermal head 25, the thermal head 25 thermally records a cyan image line by line. This cyan thermosensitive coloring layer 36
Has about 80 mJ of heat energy required for heat-sensitive color development.
/ Mm ² or more, no color develops under normal storage conditions. Since the cyan thermosensitive coloring layer 36 does not use a material that requires optical fixing, the optical fixing device 26 is in the OFF state and the optical fixing is omitted.

After the thermal recording of the yellow image, the magenta image, and the cyan image is completed, the platen drum 10 and the conveying roller pair 31 are reversed. By the reverse rotation of the platen drum 10, the rear end of the color thermosensitive recording material 11 is separated by the separating claw 32.
Is guided to the paper feeding / discharging passage 30 by the conveying roller pair 31
Be nipped in. Thereafter, the solenoid 18 is energized and the platen drum 10 is stopped. This solenoid 18 causes the clamp member 13 to move to the spring 17
Therefore, the clamp of the tip portion 11a of the color thermosensitive recording material 11 is released.

After releasing the clamp, the discharge of the color thermosensitive recording material 11 is restarted by the rotation of the conveying roller pair 31. As a result, the thermally recorded color thermosensitive recording material 11 is discharged to the tray (not shown) through the paper supply / discharge path 30.

Next, another embodiment will be described with reference to FIG. In this embodiment, the clamp member main body 41 is configured by using a metal rod 40 in which a lower portion 40a is processed into a V shape, instead of the reinforcing portion 21 formed of the fin-shaped metal plate 20. Then, the transparent portion 42 is attached to the lower portion 40a via an adhesive material. According to this embodiment, since the lower portion 40a is processed into a V-shape, fixing light and reflected light thereof are suppressed by the V-shaped portion by the transparent portion 42 and the leading end portion 11a of the color thermosensitive recording material 11 is suppressed. Wrap around
This can be optically fixed. The V-shaped surface is preferably light reflective.

As shown in FIG. 8, the clamp member main body 50 has a transparent portion 52 on the side surface of a reinforcing rod 51 having a rectangular cross section.
May be adhered or fixed with screws. Further, as shown in FIG. 9, by inserting the transparent portion 56 into the reinforcing rod 55,
The transparent member 56 may be projected from the side surface of the reinforcing rod 55 to form the clamp member main body 57. Further, instead of fitting, the transparent portion 56 may be attached to the lower surface of the reinforcing rod 55. Furthermore, as shown in FIG.
It is also possible to provide the reinforcing rod 61 having the above and mold the transparent portion 62 on the upper portion thereof.

Further, in the above embodiment, the platen drum 1
Although 0 is used, a conveyor belt or a slide table may be used instead, and a clamp member may be attached thereto. Further, the rear end of the color thermosensitive recording material may be fixed to the holding member by this clamp member.

The above embodiment is a line printer for recording by moving the thermal head or the recording paper relatively in the sub-scanning direction, but the present invention is also applied to a serial printer for two-dimensional relative movement for recording. be able to. In this serial printer, the heating elements are arranged in the main scanning direction,
A thermal head that moves in the sub-scanning direction is used during thermal recording, and the recording paper moves in the main scanning direction.

[0031]

As described above in detail, according to the present invention, the clamp member main body is composed of the transparent portion in contact with the heat-sensitive recording material and the reinforcing portion for reinforcing the transparent recording material. Since the heat-sensitive recording material that is in contact with the heat-sensitive recording material is arranged so as not to block the light so that the fixing light reaches it, the clamped portion can be fixed at the same time during the fixing. Accordingly, it is not necessary to separately provide a lamp in the paper discharge passage or the like to optically fix the clamped portion, or to temporarily stop the heat-sensitive recording material during the paper discharge, and the clamped portion can be easily optically fixed. Further, since the transparent portion is reinforced by the reinforcing portion, it is not necessary to make the transparent portion thick or thick to have sufficient mechanical strength, and the clamp member can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view of a clamp member main body of a thermal printer embodying the present invention.

FIG. 2 is a schematic diagram of a thermal printer showing a state where thermal recording and optical fixing are performed.

FIG. 3 is a perspective view showing a clamp member and a platen drum.

FIG. 4 is a graph showing the emission characteristics of an ultraviolet lamp and the transmission characteristics of a cut filter.

FIG. 5 is an explanatory diagram showing a layer structure of a color thermosensitive recording material.

FIG. 6 is a graph showing color forming characteristics of a color thermosensitive recording material.

FIG. 7 is a sectional view showing a clamp member according to another embodiment of the present invention.

FIG. 8 is a sectional view showing a clamp member according to another embodiment of the present invention.

FIG. 9 is a sectional view showing a clamp member according to another embodiment of the present invention.

FIG. 10 is a sectional view showing a clamp member according to another embodiment of the present invention.

[Explanation of symbols]

 10 Platen Drum 11 Color Thermosensitive Recording Material 13 Clamping Member 14, 41, 50, 57 Clamping Member Main Body 15 Mounting Arm 20 Fin Metal Plate 21 Reinforcing Part 22, 42, 52, 56, 62 Transparent Part 25 Thermal Head 26 Optical Fixer 40,55,61 metal rod

Claims (4)

[Claims] 1. At least one end of a thermosensitive recording material is pressed and fixed to a holding member by a clamp member, and while the holding member and the thermal head are relatively moved, thermal recording is performed on the thermosensitive coloring layer, and In a heat-sensitive printer that irradiates light from an optical fixing device to a heat-recorded portion to fix the heat-recorded portion, the clamp member includes a transparent member that contacts the heat-sensitive recording surface and a reinforcing portion that reinforces the transparent member. The thermal printer is characterized in that the transparent member is arranged such that when the transparent member is in contact with the thermal recording material, the contact surface is irradiated with light from the optical fixing device. 2. The thermal printer according to claim 1, wherein
The lower portion of the reinforcing portion is formed in a V shape.
A thermal printer characterized in that a transparent member is attached to the lower part of the character shape. 3. The thermal printer according to claim 1, wherein
The reinforcing portion is composed of a plurality of fin-shaped metal plates, and the direction of the fin-shaped metal plates is aligned with the irradiation direction of the light from the optical fixing device, and the fin-shaped metal plates are spaced apart from each other to form a gap between the heat-sensitive recording surface. A thermal printer characterized in that it is arranged such that 4. The thermal printer according to claim 1, wherein:
The thermal printer according to claim 1, wherein the reinforcing portion is made of a metal member, and the transparent member is attached so as to project from a side portion of the reinforcing portion.