JPS6018351A - Thermal recording instrument - Google Patents

Abstract

PURPOSE:To improve preservation of ink and eliminate variation of recording density, by a method wherein solid ink is transferred to a recording paper by heat of a recording element. CONSTITUTION:When recording action is commanded by a thermal recording instrument, two sets of feed rollers 23, 24 are rotated in arrow directions respectively. Accompanying the rotation, a recording paper 12 is fed from a supply tray and supplied to portion near a recording head 11. When the top end of the recording paper 12 attains to the position in opposite to top end of a nozzle, conduction control of a heating element 19 at line unit is started. If the heating element 19 is rendered conductive, solid ink 16 in the nozzle is heated and expanded rapidly and liquefied. The liquefied ink is ejected out of the top end of the nozzle and adhered to the recording paper 12 and then solidified as the temperature decreases. When the conduction is not performed, the solid ink 16 in the nozzle is held at the solid state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal recording device used in printers, facsimile machines, digital copying machines, and the like.

[Prior art]

2. Description of the Related Art Thermal transfer recording devices and inkjet recording devices are attracting attention as devices that are quiet and can record on plain paper. Among these, the thermal transfer type recording device uses an ink donor sheet as a thermal recording medium, and selectively heats the sheet with a thermal head. Then, ink is transferred to recording paper (plain paper) overlaid on the ink donor sheet to record an image. Therefore, in this apparatus, a large amount of the ink donor sheet is consumed as recording progresses, and the running cost of the apparatus is high.

On the other hand, an inkjet recording apparatus performs recording by ejecting ink from nozzles and applying it to recording paper. The diameter of the nozzle needs to be extremely small in relation to the resolution of the image. Therefore, the nozzle may become clogged due to solidification of the ink, etc., resulting in low recording reliability.

[Purpose of the invention]

In view of these circumstances, an object of the present invention is to provide a non-impact type thermal recording device that can perform economical and highly reliable recording.

[Structure of the invention]

In the present invention, a thermal recording device is equipped with a plurality of nozzles that contain ink that is solid at room temperature and fluidizes or sublimates when heated, and a heating element that selectively heats these nozzles. The heating element selectively generates heat,
The ink inside the heated nozzle is transferred to the recording paper.

〔Example〕

The present invention will be described in detail below with reference to Examples.

FIG. 1 shows the main parts of this thermal recording device.

The tip of the recording head 11 of this device is connected to the recording paper 12.
It is located a little far from the conveyance path. The recording head 11 has an aluminum pipe array 14 bonded to a heating element plate 15. Solid ink 16 is accommodated in the cavity created when these are bonded together.

FIG. 2 shows a portion of an aluminum pipe array. The aluminum pipe array 14 is a machined aluminum flat plate having a length β2 slightly longer than the recording width 11 in the main scanning direction, and holes 17 and 17 are bored on both sides for positioning with the heating element plate. It is set up. At the front end of the aluminum pipe array 14,
A large number of nozzle grooves (8) are formed in the form of toothed teeth by photo-etching. Each nozzle groove 18 has a depth of about 0.2 mm,
The nozzle grooves 18 are elongated grooves with a width of about 0.1 mm, and the density of the nozzle grooves 18 corresponds to the recording density. A large number of heating elements are arranged on the heating element plate 15 at the same density, and each nozzle groove 18 forms a nozzle by overlapping the heating elements.

Behind the nozzle groove 18, an ink storage portion 2o is formed by deeply etching an aluminum plate. This ink storage portion 2o is combined with the substrate surface 21 of the heating element plate 15 to form a relatively large cavity.

The solid ink 16 contained in this cavity is made of a wax such as carnauba wax, paraffin wax, or rice wax mixed with a dye or pigment.

The solid ink 16 is successively replenished into the ink storage portion 2o in the form of granules or powder. The replenished solid ink 16 is melted by an internal heater (not shown) and supplied to the vicinity of the nozzle groove 18 during a time period when recording is not performed.

When a recording operation is instructed in this thermal recording device, the two sets of feed rollers 23 and 24 shown in FIG. 1 each start rotating in the direction of the arrow. At the same time, the recording paper 12 is sent out from a supply tray (not shown) and is supplied to the vicinity of the recording head 11. When the leading edge of the recording paper 12 reaches a position opposite to the leading edge of the nozzle, energization control of the heating elements 19 is started line by line from that point on.

When the heating element 19 is energized, the solid ink 1 in the nozzle
6 is heated and rapidly expands and becomes fluidized. Then, it is ejected from the tip of the nozzle, adheres to the recording paper 12, and solidifies as the temperature decreases. If the power is not turned on,
The solid ink 16 in that nozzle remains in a solid state. That is, no ink transfer occurs in this portion.

Based on the above principle, ink is transferred onto the recording paper 12 only to the portions corresponding to the energized heating elements, and an image is recorded. In the nozzle where ink is ejected,
Due to the heating effect of the heating element 19, not only the solid ink in the nozzle but also the solid ink in the succeeding stage becomes slightly fluidized. Therefore, when the solid ink is ejected from the nozzle, the fluidized solid ink in the latter part enters the nozzle groove 18 and solidifies there. Solid ink is replenished near the nozzle according to the principle described above, so
Solid ink will always be supplied within the nozzle. In this way, each line can be recorded continuously.

Although the embodiments described above use solid ink that is fluidized by heating, solid ink that is vaporized by heating can be similarly applied to the present invention. Further, in the embodiment, the recording head and the recording paper are not in contact with each other, but they may be in contact with each other.

〔Effect of the invention〕

As explained above, according to the present invention, since recording is performed using solid ink that is in a solid state at room temperature, the ink has good storage stability and there is no fear of fluctuations in recording density. Furthermore, unlike an ink donor sheet, there is no need to heat the solid ink via a paper (base paper), so the resolution can be further improved.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing the main parts of a thermal recording device according to an embodiment of the present invention, and FIG. 2 is a plan view of an aluminum pipe array of a recording head used in this embodiment. 11... Recording head, 16... Solid ink, 18... Nozzle groove, 19... Heat generating element. Applicant Fuji Xerox Co., Ltd. Representative Patent Attorney Umeo Yamauchi

Claims (1)

[Claims] Equipped with multiple nozzles that contain ink that is solid at room temperature and fluidizes or sublimates when heated, and heating elements that selectively heat the ink in these nozzles, and transfers the ink to recording paper by heating the heating elements. A thermal recording device characterized by: