JPH0995009A - Printer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce density uniformly even in any range of density in the case of saving recording toner or ink by reducing the image density in an electrophotographic printer or ink jet printer. SOLUTION: Multivalued image data inputted from an image inputting part 11 is converted into binary data by a multivalue-binary conversion part 13 by the use of a screen of a screen accommodation part 12. When toner saving is determined as to be set in a toner saving set-determing part 15, a pattern for forming a dot pattern is formed by a dot pattern forming part 14, and a logical operation is conducted between the data in a depicted raster accommodation part 16 and the dot pattern formed by the dot pattern forming part so as to reduce the density of data of the raster accommodation part 16 and output the data from an image outputting part 17 to a printing part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer device that saves toner used in an electrophotographic printer engine and ink used in an inkjet printer engine.

[0002]

2. Description of the Related Art Conventionally, for example, a logical operation (AND) is performed between a drawing raster and a halftone dot pattern immediately before being output to a printer engine for the purpose of saving toner used in an electrophotographic printer engine. Thus, the density of the drawing raster is reduced, and thereby toner saving in the printer engine is realized.

In this case, the screen for creating a halftone dot pattern for density reduction used in the above logical operation and the screen used for multi-value binary conversion when creating a drawing raster are based on the same screen.

FIG. 5 is a block diagram showing a configuration of a conventional printer device capable of realizing such toner saving.

In the printer device 100, the image data for printing sent from the host device is input from the image input unit 101, and when the input data is multi-valued data, the multi-valued binary conversion unit 103 is used. Converted to binary data. At this time, the screen stored in the screen storage unit 102 is used for the multi-value binary conversion.
The binarized data is drawn in the raster storage unit 106.

[0006] Here, if the toner save setting determination unit 10
When it is determined by 5 that the toner save setting is not made, the drawing raster data in the storage unit 106 is sent to the printer engine by the image output unit 107.

Also, if the toner save setting determination unit 105
When it is determined that the toner save setting is set, the halftone dot pattern creation unit 104 creates a halftone dot pattern based on the screen stored in the screen storage unit 102. Then, the density of the data stored in the raster storage unit 106 is obtained by performing a logical operation (AND) on the already-drawn data in the raster storage unit 106 and the halftone dot pattern created by the halftone dot pattern creating unit 104. To reduce. Then, the drawing raster data with the reduced density is sent to the printer engine by the image output unit 107.

FIG. 6 is a schematic diagram showing the mechanism of the above-mentioned density reduction.

FIG. 6A shows an input multi-valued image of 8 bits / pixel, where all pixel values = 200. 6B shows a binarization screen, and FIG.
When the input data is larger, the binarized data is 1, and when the input data is smaller, the binarized data is 0. The result of binarizing the image of A of FIG. 6 on the screen of B of FIG. 6 is as shown in C of FIG. 6 (pixels of the binarized data 1 are indicated by black circles).

Here, if the toner save function is set, a halftone dot pattern for performing a logical operation is generated based on the screen of FIG. 6B. For example, when the toner save function saves up to 50% of toner, the halftone dot pattern shown in D of FIG. 6 is created based on the screen of C of FIG. 6 and the predetermined value = 128. After that, the halftone dot pattern of D of FIG. 6 and the binarized data of C of FIG.
By performing D), the image shown in E of FIG. 6 with reduced density can be obtained.

Comparing the data of C in FIG. 6 with the data of E in FIG. 6 before and after the toner save function is set, the density is reduced, which makes it possible to reduce the amount of toner in the printer engine. Becomes Then, by this processing, it becomes possible to realize toner saving.

In FIG. 7, the toner save function described above is set (O
N) shows the change of the output density with respect to the input data density.

[0013]

In the conventional printer device as described above, a screen for creating a halftone dot pattern for density reduction used in a logical operation and a multi-value binary conversion at the time of creating a drawing raster. As shown in FIG. 7, when the toner save is set for the output density with respect to the input data density, only the density of the high density part is reduced and the screen of the low density part is reduced. There is a problem that the density remains as it is and the density is not uniformly reduced.

For example, in the case of the input multi-valued image of 8 bits / pixel shown in FIG. 8A and all pixel values = 100, each pixel is pixel by pixel using the binarization screen shown in FIG. 8B. When the comparison is performed, if the input data is larger, the binarized data is set to 1, and if the input data is smaller, the binarized data is set to 0.
The result of binarization on the screen of B is as shown in C of FIG. 8 (pixels of binarized data 1 are indicated by black circles).

If the toner save function is set, a halftone dot pattern for performing a logical operation is generated based on the screen of FIG. 8B. For example, the toner save function can save up to 50% of toner. When performing
8 and the predetermined value = 128, the halftone dot pattern shown in D of FIG. 8 is created. Then, by performing a logical operation (AND) on the halftone dot pattern of D of FIG. 8 and the binarized data of C of FIG. 8, an image shown in E of FIG. 8 with reduced density can be obtained.

However, even though the toner save mode is set, the data of C in FIG. 8 and the data of E in FIG. 8 before and after performing the toner save function have the same result. The result of the save function is not appearing.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a printer device capable of uniformly reducing the density in any density region.

[0018]

A printer device according to the present invention performs a logical operation between a drawing raster created according to input data and a desired halftone dot pattern and outputs the density of the drawing raster to a printing unit. A printer device for converting
The screen for creating a halftone dot pattern for density conversion used in the logical operation is different from the screen used for multi-value binary conversion in creating a drawing raster.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. This printer device 1 performs a logical operation between a drawing raster created according to input data and a desired halftone dot pattern. A printer device for converting the density of a drawing raster to be output to a printing unit, wherein a screen for creating a halftone dot pattern for density conversion used in the logical operation is used for multi-value binary conversion when creating a drawing raster. Different from the screen.

In the printer device 1, the image data for printing sent from the host device is the image input unit 11.
When the input data is multi-valued data, it is converted into binary data by the multi-valued binary conversion unit 13. At this time, for the multi-value binary conversion, the screen storage unit 1
The screen stored in 2 is used. The binarized data is drawn in the raster storage unit 16.

Here, if the toner save setting determination unit 15
When it is determined that the toner save setting is not made by the image output unit 1
Then, the data is sent to the printer engine of the printing section according to 7.

If the toner save setting determination unit 15 determines that the toner save setting is set,
The halftone dot pattern creating unit 14 creates a halftone dot pattern based on the screen stored in the halftone dot pattern creating screen storage unit 18. Then, the density of the data stored in the raster storage unit 16 is obtained by performing a logical operation (AND) on the already drawn data in the raster storage unit 16 and the halftone dot pattern created by the halftone dot pattern creating unit 14. To reduce. Then, the drawing raster data with the reduced density is sent to the printer engine by the image output unit 17.

FIG. 2 is a schematic view showing the mechanism of concentration reduction of this embodiment.

FIG. 2A shows an input multi-valued image of 8 bits / pixel, where all pixel values = 100. 2B shows a binarization screen, and FIG.
When the input data is larger, the binarized data is 1, and when the input data is smaller, the binarized data is 0. The result of binarizing the image of A of FIG. 2 on the screen of B of FIG. 2 is as shown in C of FIG. 2 (pixels of the binarized data 1 are indicated by black circles).

Here, if the toner save function is set, a halftone dot pattern for performing a logical operation is generated based on the screen of F in FIG. At this time, the screen of F of FIG. 2 uses a screen different from the screen of B of FIG. Here, B in FIG. 2 is a FATTENING type (dot concentrated type), whereas F in FIG. 2 is BAYE.
It is an R-type (dot dispersion type) screen.

Then, for example, a maximum of 5 can be obtained by the toner save function.
When performing 0% toner save, the halftone dot pattern shown in D of FIG. 2 is created based on the screen of F of FIG. 2 and the predetermined value = 128. Then, the halftone dot pattern of FIG.
By performing a logical operation (AND) on the C binarized data of C, it is possible to obtain the image shown in E of FIG.

Comparing the data of C of FIG. 2 and the data of E of FIG. 2 before and after setting the toner save function, the density is reduced, and in the printer engine, a portion corresponding to the black circle portion of E of FIG. The toner will be fixed on.
This makes it possible to reduce the amount of toner in the printer engine.

FIG. 3 shows the change in the output density with respect to the input data density in this embodiment. As shown in the figure, if the toner save is set for the output density with respect to the input data density, the density is uniformly reduced from the low density portion to the high density portion, and the density is uniformly reduced. Function can be realized.

FIG. 4 is a flow chart showing an example of the operation of the printer device 1 of the present invention.

In step S1, the toner save setting determination unit 15 determines whether the toner save setting has been made. If the toner save setting is not set, the process proceeds to step S4 and the drawing raster storage unit 16
Image data is sent to the printer engine by the image output unit 17.

If the toner save setting is determined by the toner save setting determination unit 15 in step S1,
Proceeding to step S2, the halftone dot pattern creating unit 14
A halftone dot pattern is created based on the screen stored in the halftone dot pattern creating screen storage unit 18.

Next, in step S3, the data in the raster storage unit 16 which has already been rendered and the halftone dot pattern creating unit 14 are drawn.
Logical operation (AND) with the halftone dot pattern created by
Then, the density of the data stored in the raster storage unit 16 is reduced. Then, in step S4, the image output unit 17 sends the data of the raster storage unit 16 with the reduced density to the printer engine.

As described above, by making the screen for creating the halftone dot pattern for density reduction used for the logical operation different from the screen used for the multi-value binary conversion at the time of creating the drawing raster, for any density region It is possible to reduce the density evenly, and a higher quality toner save function can be realized.

(Embodiment 2) In Embodiment 1 described above, the case where the printer engine is an electrophotographic system is shown, and when the toner save function is set by the toner save setting judgment unit 15 in FIG. The data is output to the printer engine, which saves toner in the printer engine.

However, the toner save setting determination unit 15
May be used as the ink saving setting determination unit, and the printer engine may be an inkjet type.

As described above, the present invention does not limit the method of the printer engine.

(Third Embodiment) In the first embodiment, a screen for creating a halftone dot pattern for density reduction used in a logical operation,
Although the screen type was changed for the screen used for multi-valued binary conversion when creating the drawing raster (Fattening type and Bayer
Type) and the multi-value binary conversion method at the time of creating the drawing raster may be the error diffusion method.

(Fourth Embodiment) In the first embodiment, a screen for creating a halftone dot pattern for density reduction used in a logical operation,
Although the screen type was changed for the screen used for multi-valued binary conversion when creating the drawing raster (Fattening type and Bayer
Type) and a halftone dot pattern for density reduction used for logical operation may be created by a method without using a specific screen, for example, a method of randomly generating a pattern within the halftone dot pattern.

(Fifth Embodiment) In the first embodiment, a screen for creating a halftone dot pattern for density reduction used in a logical operation,
Although the screen type was changed for the screen used for multi-valued binary conversion when creating the drawing raster (Fattening type and Bayer
Type) and the same screen may be used, and the places to be overlapped may be shifted when performing a logical operation.

[0040]

As described above, according to the present invention,
A printer for converting the density of a drawing raster by logically calculating a drawing raster and a halftone dot pattern immediately before being output to the printer engine draws a screen for creating a halftone dot pattern for density reduction used in the logical operation. By using a screen different from the screen used for multi-value binary conversion when creating a raster, it is possible to reduce the density uniformly in any density area, and it is possible to realize a higher quality toner save function. There is an effect.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing the mechanism of concentration reduction of the embodiment.

FIG. 3 is an explanatory diagram showing a change in output density with respect to input data density in the embodiment.

FIG. 4 is a flowchart showing the operation of the embodiment.

FIG. 5 is a block diagram showing a configuration of a conventional example.

FIG. 6 is a schematic diagram showing a mechanism of density reduction of a conventional example.

FIG. 7 is an explanatory diagram showing a change in output density with respect to input data density in a conventional example.

FIG. 8 is a schematic diagram showing a problem of a low-density region portion in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer device 11 Image input unit 12 Screen storage unit 13 Multi-value binary conversion unit 14 Halftone dot pattern creation unit 15 Toner save setting determination unit 16 Raster storage unit 17 Image output unit

Claims (1)

[Claims] 1. A printer device for performing a logical operation between a drawing raster created according to input data and a desired halftone dot pattern to convert the density of the drawing raster to be output to a printing unit. A printer device characterized in that a screen for creating a halftone dot pattern for density conversion used for is different from a screen used for multivalued binary conversion when creating a drawing raster.