JPH0596736A - Thermal ink jet recorder - Google Patents

Abstract

PURPOSE:To obtain a thermal ink jet recorder which can form a clear recording image stably with high density. CONSTITUTION:The thermal ink jet recorder comprises a first inclining face, disposed on the side for introducing a film 11 to a thermal head 2 and inclining from the second face side of the film 11 on the side of the thermal head 2 toward the first face side of the film 11 on the side of a recording paper 3, at the contacting part with the first face and a blade 18a which can deform resiliently to remove excessive ink. The thermal ink jet recorder further comprises a blade 18b having a second inclining face in parallel with the first inclining face which cooperates with the first inclining face of the blade 18a to hold the film 11 between and resiliently deform to remove excessive ink from the second face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal ink jet recording apparatus.

[0002]

2. Description of the Related Art A thermal ink jet recording apparatus for recording an image by running a belt-shaped film having a large number of minute holes for holding ink while keeping contact with a thermal head and ejecting the ink onto an opposing recording paper. The conventional example will be described with reference to FIGS. 4, 5 and 6. In this recording apparatus, the ink cartridge 1 is provided with a film 11 and an ink storage unit 12 inside, and a thermal head 2
At the same time, it is driven in the main scanning direction (directions of arrows A and B in FIG. 4) by the rod 5 and the spiral rod 6. As the ink cartridge 1 moves, ink drops 16 from the film 11 are ejected onto the recording paper 3 sent in the sub-scanning direction (direction of arrow C in FIG. 4) along the platen 7 to form a recorded image 4. The film 11 in which the ink 15 is filled in the minute holes 14 from the ink storage unit 12 has the blade 13 arranged at the opening of the ink cartridge 1 removed the excess ink 15 adhering to the surface, and the thermal head 2 is positioned. Run to the printed area. Ink 1 in the micro holes 14
5 is rapidly heated by a heating resistor (not shown) of the thermal head 2 in accordance with a recording signal in the printed portion, the low boiling point component is boiled and then vaporized to generate a vapor bubble, which is generated by itself. It is ejected in the direction of the recording paper 3 by the pressure (see FIG. 6). The ejected ink 15 becomes an ink droplet 16, which adheres to and permeates the recording paper 3 facing each other across a minute gap to form a recorded image 4. Here, one of the heating resistors of the thermal head 2 usually corresponds to one of the recording dots forming the recorded image 4. When the density of the minute holes 14 is higher than the density of the heating resistor, one recording dot is formed by the ink droplets 15 ejected from the plurality of minute holes 14. Therefore, some micropores 14
Even when the ink droplets 15 become clogged and the ejection of the ink droplets 15 becomes impossible, it is possible to perform recording with high print quality and without causing a large obstacle to the recording result. Further, in the thermal inkjet recording device, unlike a recording device such as a thermal transfer type or a thermal type,
Thermal head 2 and film 1 that runs in contact with it
Since a thin ink layer is interposed between the thermal head 1 and the magnetic head 1, the heat generating resistor of the thermal head 2 is less likely to be broken due to heat storage or abrasion.

The pair of blades 13 provided in the ink cartridge 1 are at positions for sandwiching the front and back surfaces of the film 11, as shown in detail in FIGS. The ink 15 is removed, and the ink 15 is supplied into the minute holes 14 that have not been sufficiently filled with the ink 15 by the ink storage unit 12. Further, the blade 13 is used for the ink 1
5 has the role of preventing drying.

[0004]

However, since the blade 13 has an approximately semicircular cross section and has almost no elasticity, the film 11 has the thermal head 2 formed therein.
15 by the blade 13 when traveling in the direction of
The removal status of is not stable. As a result, the state of the ink 15 on the front and back surfaces of the film 11 after passing through the blade 13 lacks uniformity. If the amount of ink deposited on the surface of the film 11 on the side of the thermal head 2 is too small, the amount of ejected ink will be small, and it will be difficult to form a high-density recorded image. Not only contaminates but also deteriorates print quality. Further, the ink adhered to the surface of the film 11 on the recording paper 3 side deflects the flight direction of the ink droplet 16 due to the surface tension when the ink 15 is ejected from the minute holes 14 to form the recorded image 4 with high positional accuracy. Hinder.

Further, in the case of adopting the constitution of the ink cartridge 1, if the pressing pressure of the blade 13 is reduced so that the film 11 is not broken or worn due to the running resistance of the blade 13, the hermeticity of the cartridge 1 when the apparatus is stopped Is poor, and the ink 15 is easily dried. As a result, the characteristics of the ink 15 are changed, the fine holes 14 of the film 11 are clogged, and a recorded image with high print quality cannot be formed.

Although Japanese Patent Publication No. 1-52187 discloses a thermal ink jet recording apparatus having the same operation principle, this apparatus also does not solve the above-mentioned problems.

[0007]

A thermal ink jet recording apparatus according to the present invention has a large number of minute holes each holding a small amount of ink so that the ink can be ejected toward a recording paper which is arranged facing the first surface. A strip-shaped film that can run in the longitudinal direction, a thermal head that is provided on the second surface side of the film and that ejects the ink held in the minute holes toward the recording paper by heating, and the thermal head Contact with the first surface is disposed on the introduction side of the film to the first slope inclined from the second surface side of the film toward the first surface side corresponding to the traveling direction of the film First means for elastically deforming so as to remove excess ink attached to the first surface, and for clamping the film in cooperation with the first inclined surface of the first means. First slope To remove excess ink adhering to the second surface has a second inclined surface parallel and a second means for resiliently deformed.

[0008]

Next, an embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. In the thermal ink jet recording apparatus of this embodiment, the ink cartridge 1 has a film 11 and an ink storage unit 12 inside.
And is moved in the main scanning direction (directions of arrows A and B in FIG. 1) by the rod 5 and the spiral rod 6 together with the thermal head 2. Along the platen 7 as the ink cartridge 1 moves, the sub-scanning direction (direction of arrow C in FIG. 1)
The operation of ejecting the ink droplets 16 held in the minute holes 14 of the film 11 onto the recording paper 3 sent to the recording paper 3 to form the recorded image 4 is similar to that of the conventional recording apparatus.

The blades 18a and 18b are formed of the film 11
Of the ink cartridge 1 are respectively arranged on the introduction side of the thermal head 2 and the ejection side of the thermal head 2.
It is fixed to. The blades 18a and 18b are preferably made of elastic material such as urethane rubber or silicon rubber.
The sloped surface of the blade 18a on the recording paper 3 side, which is in contact with the film 11, faces the outside of the ink cartridge 1, and the film 18 on the blade 18b on the thermal head 2 side.
The slanted surfaces in contact with 1 are directed to the inside of the ink cartridge 1, and these slanted surfaces form surfaces parallel to each other and sandwich the film 11. As shown in FIG. 2 (a), when the film 11 is stationary, the blades 18 a and 1 forming a pair with the film 11 sandwiched therebetween.
8b is stationary at a position where the inclined surfaces are to be brought into close contact with each other. As shown in FIG. 2B, when the film 11 travels in the direction of arrow A and the blades 18a and 18b are positioned at the outlet of the ink cartridge 1, the blade 18a
And 18b are curved in the traveling direction of the film 11. In this case, as shown in FIG. 3, since the nipping angle a1 at which the tip of the blade 18a is in contact with the film 11 is large, the sliding resistance between the blade 18a and the film 11 is large, and the film 11 side of the recording paper 3 side. The ink 15 on the surface of is almost completely scraped off. On the other hand, on the surface of the film 11 on the thermal head 2 side, since the holding angle b1 of the blade 18b in contact with the film 11 is small, the sliding resistance between the blade 18b and the film 11 is small, and the ink film 17 having a uniform thickness is formed. Remains. The thickness of the ink film 17 affects the amount of ejected ink and the density of the recorded image 4, but can be optimized by considering the hardness and size of the blades 18a and 18b, the angle of the slope, and the like. is there. Since almost no ink 15 remains on the surface of the film 11 on the recording paper 3 side, the ejected ink droplets 16 fly without being deflected, and a recorded image 4 with high positional accuracy is formed. In addition, as shown in FIG. 2C, when the film 11 travels from the outer side to the inner side (in the direction of arrow B) of the ink cartridge 1 and the blades 18 a and 18 b are located at the inlet of the ink cartridge 1, the blade 18 a And 1
8b is curved in the opposite direction to the above case.

Further, as shown in FIG. 1, the pair of blades 18a and 18b are installed on the lead-out side from the thermal head 2 so that their slopes are symmetrical to the blades 18a and 18b on the lead-in side. At times, the pair of blades come into contact with each other at their surfaces, so that the ink cartridge 1
The airtightness is good, and the ink in the ink cartridge 1 is unlikely to dry. At this time, the operation of the blade arranged on the lead-out side from the thermal head 2 is in the opposite direction due to the symmetrical arrangement of the slopes, but the blades 18a and 18b arranged on the introduction side to the thermal head 2 are described above. The operation is similar to.

Although the blades in the above-described embodiment are arranged on the introduction side to the thermal head 2 and the extraction side from the thermal head 2, they may be arranged on the introduction side to the thermal head 2 as described above. The ejected ink droplets 16 fly without being deflected to form a recorded image 4 with high positional accuracy. When the ink cartridge 1 is not used, the blades 18a and 18b can be provided near the thermal head 2.

[0012]

As described above, according to the present invention,
The first inclined surface is arranged on the side where the film is introduced to the thermal head and inclines from the second surface side of the film on the thermal head side toward the first surface side of the film on the recording paper side in correspondence with the running direction of the film. The film is formed in cooperation with the first means which has a contact portion with the first surface and is elastically deformed so as to remove excess ink adhering to the first surface, and the first inclined surface of the first means. By providing a second means having a second slope parallel to the sandwiching first slope and elastically deforming so as to remove the excess ink adhering to the second surface, the film can be formed by the first means. The ink on the first surface is almost completely scraped off, and since the ink film having a uniform thickness remains on the second surface of the film by the second means, the ejection amount and ejection direction of the ink are stabilized, It is possible to stably obtain clear recorded images with high density. That.

Further, by disposing the blade at the film entrance / exit of the ink cartridge, the ink cartridge is improved in hermeticity, and it is possible to form a high quality recorded image without clogging.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a detailed view of the blade shown in FIG.

FIG. 3 is a diagram for explaining the effect of the blade in one embodiment.

FIG. 4 is a configuration diagram of a conventional example.

5 is a detailed view of the blade shown in FIG. 4. FIG.

FIG. 6 is a diagram for explaining the action of the blade and the ink ejection state in the conventional example.

[Explanation of symbols]

 1 Ink Cartridge 2 Thermal Head 3 Recording Paper 4 Recorded Image 5 Rod 6 Spiral Rod 7 Platen 11 Film 12 Ink Storage Section 14 Micropore 15 Ink 16 Ink Drop 17 Ink Film 18, 18a, 18b Blade

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 2/32 2/325 31/14 7318-2C 32/02 Z 7318-2C 8907-2C B41J 3 / 20 109 J 8907-2C 117 A

Claims (3)

[Claims] 1. A strip-shaped film having a large number of minute holes each holding a small amount of ink so that it can be ejected toward a recording paper which is arranged so as to face the first surface, and which can run in the longitudinal direction. A thermal head which is provided on the second surface side of the film and ejects the ink held in the minute holes toward the recording paper by heating, and a thermal head which is arranged on the introduction side of the film to the thermal head. Excessive adhered to the first surface having a first inclined surface inclined from the second surface side of the film toward the first surface side in a contact portion with the first surface corresponding to a traveling direction A first means for elastically deforming to remove ink, and a second slope parallel to the first slope for sandwiching the film in cooperation with the first slope of the first means. Excess ink attached to the second surface And a second means for elastically deforming so as to remove the thermal ink jet recording apparatus. 2. The first means and the second means arranged on the introduction side of the film to the thermal head are also provided on the extraction side of the film from the thermal head, and the first slope and 2. The thermal ink jet recording apparatus according to claim 1, wherein the inclination directions of the second slopes are symmetrical with respect to the thermal head. 3. An ink cartridge for accommodating the film and a means for storing the ink is provided, and each of the first means and the second means is provided at a port of the film of the ink cartridge. The thermal inkjet recording device according to claim 2.