JPH06286140A - Ink jet printer - Google Patents

Abstract

PURPOSE:To provide an ink jet printer which can carry out high quality printing in a plurality of kinds of resolution by a method wherein an inclination of a print head is changed. CONSTITUTION:An inclination of a print head of a printing part 1 is varied according to a position of a lever, and a dot pitch is changed. Besides, a dot of a diameter corresponding to the dot pitch is formed with a dot diameter control part 3, and printing is controlled on the basis of a paper feed amount corresponding to the dot pitch and a feed distance of a carriage to print faithfully input images of various kinds of resolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer.

[0002]

2. Description of the Related Art In conventional ink jet printers, the dot pitch is fixed because the print head is fixed,
It was possible to print only with the resolution corresponding to the dot pitch.

[0003]

In the above-mentioned prior art, when printing an image of a resolution other than the fixed resolution, the input image data is converted into image data approximated by the fixed resolution by a software algorithm. , Printing was performed based on the data. For example, when an image with a resolution of 160 DPI is printed by a printer with a resolution of 180 DPI, 160 DPI with a dot pitch of 180 DPI.
Image is approximately created, and printing is performed based on the created image data. Therefore, the original image cannot be printed faithfully and the image quality is degraded.

An object of the present invention is to provide an ink jet printer which can faithfully print an input image by switching the inclination of the print head and changing the dot pitch.

[0005]

According to the present invention, there is provided an ink jet printer for performing printing by scanning a print head having a plurality of nozzles in a direction perpendicular to a feed direction of a recording sheet, and the print head in the feed direction of the recording sheet. The above problem is solved by providing a switching means for switching the inclination of the recording sheet and a control means for controlling the feed amount of the recording sheet according to the inclination of the print head by the switching means.

The control means controls the feed amount of the recording paper, the feed amount of the print head, and the diameter of a dot to be printed by the nozzle according to the inclination of the print head by the switching means. Is desirable.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the main part of a piezoelectric ink jet printer which prints by scanning a print head having a plurality of nozzles in a direction perpendicular to the paper feed direction. In the figure, reference numeral 1 is a printing unit including a print head having 24 nozzles, a head carriage, and the like, and 2 is a switching unit including a lever for switching the inclination of the print head with respect to the paper feeding direction. This lever can be fixed in place. The print head is interlocked with the lever, and the inclination of the print head with respect to the paper feeding direction is changed according to the position of the lever. Reference numeral 3 is a dot diameter control unit that controls the diameter of dots printed by nozzles according to the position of the lever, and 4 is a printer control unit that controls the paper feed amount and head carriage feed amount according to the lever position. Therefore, these constitute a control means for controlling the feed amount of the recording paper, the feed amount of the print head, and the diameter of the dots recorded by the nozzles according to the inclination of the print head. Reference numeral 5 denotes a switching control unit for switching connection between the personal computer a and the facsimile b to the printer control unit 4 according to the position of the lever. In addition,
Image data of 180 DPI is sent from the personal computer a, and image data of 200 DPI is sent from the facsimile b.

FIG. 2 shows the nozzle arrangement of the print head. A indicates the paper feeding direction, and B indicates the scanning direction of the print head. p1 to p24 are nozzles, 0.5m on the same line
The nozzle rows are arranged at m intervals. When the angle formed by this nozzle row and the paper feed direction A is θ, the dot pitch d in the paper feed direction A is 0.5 mm × cos θ
And the dot pitch D in the print head scanning direction B
Is 0.5 mm × sin θ. The values of the dot pitches d and D can be changed by switching the angle θ, that is, the inclination of the print head. Therefore, printing is performed by inclining the print head so that the dot pitches d and D have values corresponding to the desired resolution.

Next, the operation will be described.

First, the case of printing with 180 DPI image data from the personal computer a will be described.

When the lever 2 is switched to the first position, the print head is tilted in conjunction with this. In the case of a resolution of 180 DPI, the dot pitch in the paper feed direction A, that is, the dot pitch d is 0.141 mm, so the dot pitch d
And the angle θ is 0.141 = 0.5 × cos θ. Therefore, the angle θ is 73.6 °. That is, when the lever 2 is switched to the first position, the print head is tilted by 73.6 ° with respect to the paper feed direction A in conjunction with this. The dot pitch D is 0.5 m
m × sin73.6 ° = about 0.48 mm.

Further, it is necessary to control the dot diameter according to the resolution. 3A shows the cross section of the nozzle, and FIG. 3B shows the relationship between the head drive voltage and the dot diameter. In FIG. 1A, reference numeral 31 is a piezoelectric element to which the head drive voltage is applied. The nozzle diameter n is 0.06 mm. In FIG. 7B, the horizontal axis represents the head drive voltage and the vertical axis represents the dot diameter. Now, assuming that the dot diameter in the case of 180 DPI is 0.2 mm, the head drive voltage is 100 v.

Therefore, by switching the lever 2 to the first position, the switching control unit 5 switches the connection to the personal computer a side, the print head of the printing unit 1 is tilted by 73.6 °, and the dot diameter control unit 3 is 100v. The ink is ejected by the head drive voltage of, and the printer control unit 4 sets the paper feed amount to 0.141 mm × 24 = 3.384 mm and the carriage feed amount per step to 0.48 mm.
Printing can be performed with DPI.

Next, 200 DP from the facsimile b
A case of printing with the image data of I will be described.

When the lever 2 is switched to the second position, the print head tilts in conjunction with this. In the case of a resolution of 200 DPI, the dot pitch in the paper feed direction A, that is, the dot pitch d is 0.127 mm, so the dot pitch d
And the angle θ is 0.127 = 0.5 × cos θ. Therefore, the angle θ is 75.3 °. That is, when the lever 2 is switched to the second position, the print head is tilted by 75.3 ° with respect to the paper feeding direction A in conjunction with this. The dot pitch D is 0.5 m
m × sin 75.3 ° = about 0.484 mm.

Now, assuming that the dot diameter in the case of 200 DPI is 0.18 mm, the head drive voltage is 96 v, as shown in FIG.

Therefore, by switching the lever 2 to the second position, the switching control section 5 switches the connection to the facsimile b side, and the print head of the printing section 1 is at 75.3 °.
The tilt and dot diameter control unit 3 ejects ink by the head drive voltage of 96v, the printer control unit 4 sets the paper feed amount to 0.127 mm × 24 = 3.048 mm, and the carriage feed amount per step to 0.484 mm. So I will do 20
Printing can be performed with 0 DPI.

As described above, printing can be performed by switching the resolution.

In the above embodiment, one of the two types of resolutions can be selected, but the number of types of resolutions is not limited to this and may be set arbitrarily.

Further, the values of the nozzle interval, the carriage feed amount in one step, the head drive voltage and the nozzle diameter are not limited to those in the above embodiment, and may be set arbitrarily.

[0022]

According to the present invention, since the dot pitch is changed by tilting the print head, it is possible to faithfully print input images, characters, etc. of various resolutions.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an inkjet printer according to the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the inkjet printer according to the present invention.

FIG. 3 is an explanatory diagram for explaining the operation of the inkjet printer according to the present invention.

[Explanation of symbols]

 2 Lever 3 Dot diameter control unit 4 Printer control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 2/055 2/51 2/255 11/42 A 9011-2C 9012-2C B41J 3/04 103 A 9211-2C 3/10 101 T 9211-2C 106 E

Claims (2)

[Claims] 1. An ink jet printer for performing printing by scanning a print head having a plurality of nozzles in a direction perpendicular to a recording paper feed direction, and a switching means for switching the inclination of the print head with respect to the recording paper feed direction. Depending on the inclination of the print head by the switching means,
An ink jet printer comprising: a control unit that controls the feeding amount of the recording paper. 2. The control means controls the feed amount of the recording paper, the feed amount of the print head, and the diameter of a dot recorded by the nozzle according to the inclination of the print head by the switching means. The inkjet printer according to claim 1, wherein the inkjet printer is provided.