JP2000153606A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the density of image from over increasing when the density of an output image is enhanced by writing a same imaging data twice onto a recording medium with ink being ejected from the nozzle of an ink jet head. SOLUTION: An ink jet printer 4 develops image information to be outputted into a bit map memory in the form of a raster data and the image information developed into the bit map memory is outputted onto a recording medium by ejecting ink from the nozzle of an ink jet head. When identical image information is written twice, the CPU 10 in the ink jet printer 4 writes the image information, as it is, by 100% for the first time imaging and writes the image information at a ratio selected between 0-100% for the second time imaging. The CPU 10 sets the imaging ratio the second time automatically depending on a recording medium being used. Further, an optical imaging ratio is selected for the second time imaging from the table of a controller based on the type of the recording medium being used and the imaging conditions, e.g. the temperature and humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet printer having a two-time drawing mode.

[0002]

2. Description of the Related Art An ink jet printer which develops image information to be output in a bit map memory in the form of raster data, and outputs the image information developed in the bit map memory to a recording medium by discharging ink from nozzles of an inkjet head. Is conventionally known. In this type of printer, since the amount of ink ejected from the ink jet head is limited, when printing on a recording medium such as a cloth or a vinyl chloride sheet, a sufficient density may not be obtained. Therefore, conventionally, in order to increase the density of the image,
There is a mode in which the same drawing data is drawn twice.

[0003]

In the twice writing mode of the ink jet printer, the first and second printings are the same, and the printing result is always 200%. Therefore, in the case of data close to solid painting, the image formation result may be too dark and liquid dripping may occur.

If a solvent-based ink is used as the ink discharged from the nozzles of the head, it is possible to print on a medium, for example, a PVC (vinyl chloride) cutting film, which cannot be printed with a conventional aqueous ink. This is a media for cutting out characters and pictures with a conventional cutting plotter and pasting them on signboards.
Inexpensive and excellent in weather resistance.

However, the PVC cutting film is
Since it is not made for inkjet, the degree of penetration of ink varies, and the manufacturer and weather resistance (1
Year, 3 years, 5 years), etc., there are various types of information, from one that is drawn too dark once to one that is drawn too light twice. An object of the present invention is to provide an ink jet printer that can handle such media.
It is an object of the present invention to be able to deal with a medium that is too light for two-time drawing and too dark for two-time drawing.

[0006]

In order to achieve the above-mentioned problems, the present invention expands image information to be output in a bitmap memory in the form of raster data, and converts the image information expanded in the bitmap memory. In an ink jet printer that discharges ink from nozzles of an ink jet head and outputs the same to a recording medium, when drawing the same image information twice, the first time, 100% of the image information is directly drawn,
In the second time, a ratio of 0 to 100% is selected for drawing. In addition, the second drawing ratio is automatically set according to the recording medium to be used.
A table of a drawing ratio corresponding to a drawing environment such as a type of a recording medium to be used, temperature and humidity is prepared, and an optimum second drawing ratio is selected from the table based on the drawing environment data. is there.

[0007]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 is a block diagram showing a configuration of an ink jet printer (4) to which an image forming method according to one embodiment of the present invention is applied. The interface (6) of the inkjet printer (4) includes:
A host computer (2) for outputting image information such as a design drawing created using an input device (not shown) in the form of vector data is connected.

[0008] The ink jet printer (4) is configured to convert vector data sent from the host computer (2) into raster data and print it out. Vector data transmitted from the host computer (2) is taken into the RAM (8) via the interface (6) having a FIFO buffering function.
The CPU (10) analyzes the data with respect to the drawing vector data stored in the RAM (8) based on the program stored in the ROM (12), and performs a dividing process and a sorting with a preset bandwidth. Preprocessing such as processing is performed to arrange vector data included in each band into an intermediate code format (for example, vector data).

The image processor (16) has a RAM (8)
DDA for images in the intermediate code format stored in
After processing, raster data is stored in bitmap memory (1
Expand to 8). The raster data developed in the bitmap memory (18) is sequentially sent to the inkjet head (14) via the data transfer circuit (20), and the raster data is copied to the head transfer memory (22). As shown in FIG. 2, the inkjet head (14) is driven by a head drive unit (26) in a direction crossing the inkjet head (X-axis direction).
It reciprocates left and right (X-axis direction) while discharging ink from the nozzles.

On the other hand, the paper (24) is supplied to a paper driving unit (2).
8), the raster data is driven in the vertical direction (Y-axis direction), and the ink jet head (14) prints out the raster data for each band on the paper (24). The ROM (1
In 2), a drawing program (30) is stored twice, and the inkjet printer (4) draws twice by a command from the host computer (2) or by a command from the operation panel (32). Mode.

When the printer enters the drawing mode twice and writes the same drawing data twice, the first drawing is performed 100% as it is as shown in FIG.
At the third time, a ratio is selected from 0 to 100% and printing is performed. In FIG. 3, the squares correspond to one-dot ink droplets,
The numbers in the squares indicate the number of times the nozzles of the inkjet head (14) have ejected ink in the same area.
(A) shows an example of 100% solid coating. As one function of the printer (4), in the second drawing mode, the second drawing ratio (0 to 100%) is set for each ink by a dedicated command or the like from the operation panel (32) or the host computer (2). It is specified.

In another function of the printer (4), 2
In the degree drawing mode, a table (34) of a drawing ratio according to the type of printing medium and the environment (temperature and humidity) is set in the ROM (12), and the CPU (10) sets the temperature sensor (3).
6) The optimum drawing ratio is automatically selected from the drawing ratio table (34) based on environmental information from the humidity sensor (38) and media information from the operation panel (32) and the host computer (2). It is configured to: The operator can select any of the above functions by operating the operation panel (32). FIG. 3 (B)
FIG. 3 shows an example of the second drawing at a drawing ratio of 50%.
(C) shows the result of the second drawing in which the second drawing is performed at a drawing ratio of 50%. FIG. 3D shows a drawing ratio of 25%.
3E is an example of the second drawing, and FIG.
The result of drawing twice at a drawing ratio of 5% is shown.

[0013]

Since the present invention is constructed as described above, it is possible to obtain an image forming result of a desired density in accordance with the type of recording medium to be used, the density of image forming data, and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an inkjet printer according to the present invention.

FIG. 2 is an explanatory diagram of an entire image output by an inkjet printer.

FIG. 3 is an explanatory diagram of the present invention.

[Explanation of symbols]

 2 Host Computer 4 Inkjet Printer 6 Interface 8 RAM 10 CPU 12 ROM 14 Inkjet Head 16 Image Processor 18 Bitmap Memory 20 Data Transfer Circuit 22 Head Transfer Memory 24 Paper 26 Head Drive 28 Paper Drive 30 Twice Drawing Program 32 Operation Panel 34 Drawing ratio table 36 Temperature sensor 38 Humidity sensor

Claims (3)

[Claims] 1. An ink jet printer, which develops image information to be output in a bitmap memory in the form of raster data, and outputs the image information developed in the bitmap memory to a recording medium by discharging ink from nozzles of an inkjet head. When the same image information is drawn twice in the printer, the first time, 100% of the image information is directly drawn,
An ink jet printer characterized in that the image is formed by selecting a ratio of 0 to 100% for the second time. 2. The ink jet printer according to claim 1, wherein a second image forming ratio is automatically set according to a recording medium to be used. 3. A table of a drawing ratio corresponding to a drawing environment such as a type of a recording medium to be used, temperature and humidity, and the like, and an optimum second drawing ratio is selected from the table based on the drawing environment data. The inkjet printer according to claim 1, wherein: