JPS62104766A - Ink jet printer - Google Patents

Abstract

PURPOSE:To obtain tonal recording by jetting different amounts of ink by a method in which holes of different arranging densities are partly provided in an ink supply sheet and selectively heated by a thermal head. CONSTITUTION:Holes 1a-1d of different arranging densities are periodically provided in the moving direction of an ink supply sheet 1, and position-detecting holes 3 of a diameter greater than the thickness of the sheet 1 are also provided in the sheet 1. When the holes 3 pass through between a luminous element 11 and a light receiving element 12, the output of the element 12 is sent out. On the basis of the output signal, voltage is applied to the head 4 by selecting timing to contact with the heating element of the head by a targeted arranging density of holes, a desired density of ink droplets can be jetted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording apparatus.

[Summary of the invention]

The present invention is an inkjet method in which ink filled in the holes of an ink supply sheet is heated by a thermal head, and the ink is ejected by the pressure of generated bubbles to perform recording. By providing different holes and selectively heating them with a thermal head, different amounts of ink are ejected to perform gradation recording.

[Prior Art] Conventionally, an inkjet method is widely known as a method of non-impact recording. The inkjet method is a recording method with excellent features such as low noise, miniaturization, and easy color printing, but it has the disadvantage that nozzles are easily clogged. As a solution to this problem of nozzle clogging, a printer using an ink supply sheet has been proposed in Japanese Patent Application Laid-open No. 71260/1983. This type of inkjet printer uses an ink supply sheet with many fine holes formed in it, and a thermal head, for example, is brought into contact with one side of the ink supply sheet, and the holes in the ink supply sheet are filled with heat from this thermal head. In this method, bubbles are generated at the interface between the ink and the thermal head, and the pressure of the bubbles causes the ink to be ejected from the holes to print on the opposing recording paper.

[Problem that the invention seeks to solve]

However, in this conventional method, the arrangement density of the holes provided in the ink supply sheet is uniform over the entire surface of the ink supply sheet, so it is impossible to perform gradation recording by changing the amount of ejected ink. there were.

Means for Solving Problems R] The present invention has been made with the aim of solving the above problems, and includes forming a large number of holes with partially different arrangement densities in an ink supply sheet.

[Effect]

Since the arrangement density of the holes formed in the ink supply film differs depending on the part, different amounts of ink can be selectively ejected by selecting the timing when the ink supply sheet touches the thermal head section and heating the thermal head with electricity. This enables gradation recording.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

In Figures 1 to 4, 1 is 10 microns thick to 2
An ink supply notebook made between 0.00 microns,
The material is made of metal or resin. The ink supply sheet has many parts with different hole arrangement densities,
formed periodically. In FIG. 1, in the moving direction of the ink supply sheet 1, there is a portion 1 with different hole arrangement densities.
A to 1d are formed periodically. The sizes of the holes are almost the same, but the hole arrangement density is the highest in the density 8 part 1a, followed by the density part lb, then the density 0 part 101, and the density 4.
Each part is different, such as part 1d. Further, one or more position detection holes 3 are provided in a part of the ink supply sheet 1. The size of the position detection hole 3 is made larger than the thickness of the ink supply sheet 1 so that it is not filled with ink. Figure 2 (A)
, (B) shows the ink supply sheet 1 and the thermal head 4.
FIG. The thermal head 4 is provided with a plurality of thermal head 7 heat generating parts 4a. Since the ink supply sheet 1 is provided with several types of parts with different hole arrangement densities, the number of holes in contact with one thermal head heat generating section 4a differs depending on the hole arrangement density of each part. FIG. 3 is a schematic diagram showing the configuration of an apparatus according to the present invention. In FIG. 3, 5 is an ink tank;
It holds ink 6 inside. 7 is a platen, and a recording paper 8 is disposed on the platen 7 facing the ink supply sheet 1-1 with a slight gap between the recording paper 8 and the thermal head 4 as shown in FIG. , the positional relationship with the portions 1a to 1d of the ink supply sheet 1 having different hole arrangement densities is detected.

Next, the operation of the embodiment will be explained. The ink supply sheet 1 is guided by rollers 9 and 10 to the ink tank 5.
, which circulates around the thermal head 4 and is configured in a loop shape, and the holes 2 of the ink supply sheet l that have passed through the ink tank 5 are filled with ink, which reaches the thermal head 4. At the position of the thermal head 4, the ink supply sheet l is in contact with the thermal head heat generating part 4a, and when voltage is applied to the thermal head 4 in this state, the thermal head heat generating part 4a suddenly generates heat, causing the ink supply sheet l to A bubble is generated at the interface with the ink in the hole 2, and the ink is ejected from the hole 2. The ejected ink droplets adhere to the recording paper 8 and printing is performed. As mentioned above, the ink supply sheet l is periodically provided with several types of parts with different hole arrangement densities, so the thermal Ink droplets of a desired density can be ejected by applying voltage to the head. The ejected ink droplets are printed on the recording paper 8.
Dots with a concentration corresponding to the arrangement density of the holes are formed on the top. The position detection hole provided in the ink supply sheet 1 is
When passing between the light emitting element 11 and the light receiving element 12, a signal is output from the light receiving element I2. Based on this signal, the positional relationship between the thermal head 4 and the portions 1a to 1d of the ink supply sheet 1 having different hole arrangement densities is detected to obtain the printing timing. In this embodiment, the light emitting element 11 and the light receiving element 12 are arranged with the ink supply sheet 1 in between, but the pixel elements are arranged on one side of the ink supply sheet 1, and the reflected light is used to position Detection hole 3
It may be configured to detect. In this example, 4+[n
The explanation has been given by taking as an example an ink supply sheet provided with portions with different hole arrangement densities, but the type of hole arrangement density is set depending on the intended number of recording gradations.

〔Effect of the invention〕

As described above, in the present invention, an ink supply sheet in which a large number of holes with partially different arrangement densities are formed is selectively heated by a thermal head to eject ink droplets with different densities to obtain a desired number of holes. By forming 14 degree dots on recording paper, it is possible to perform gradation recording, which was impossible with conventional inkjet methods.

[Brief explanation of drawings]

Figure 1 is a partial plan view of the ink supply sheet, Figure 2 (A)
2(B) is a partial sectional view showing the relationship between the ink supply sheet and the thermal head, and FIG. 3 is a partial plan view showing the relationship between the ink supply sheet and the thermal head. The schematic explanatory diagram, FIG. 4, is an explanatory diagram showing the ink supply sheet position detection section. ---- Ink supply note 2 - Hole 3 - One position detection hole 4 - Thermal head 5 - One - Ink tank 6 - Ink 7 Platen 8 Recording paper 11 - ---- Light emitting element 12-1 Light receiving element Part 1 and side view of ink supply sheet Figure 1 Figure 2 (A,) Figure 2 (B) Figure 4 Approximately 6V moon diagram Figure 3

Claims (1)

[Claims] An ink supply sheet in which a large number of fine holes with partially different arrangement densities are formed, a thermal head that heats ink filled in the holes of the ink supply sheet to generate bubbles and eject the ink, and the ink supply sheet. and an ink tank filled with ink, and the thermal head selectively heats holes with different arrangement densities of the ink supply sheet to eject different amounts of ink to perform gradation recording. Inkjet printer.