JPH11112789A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the amount of toner without damaging the quality of a picture. SOLUTION: A picture correcting part 3 executes correcting processing such as antialiasing processing on the inputted picture data in the bit map format in a picture buffer 2 and sends corrected data to a picture selecting part 52. A toner save control part 4 selects mask pattern data corresponding to inputted picture data and sends a mask control signal showing a selected mask pattern to a mask control part 51. The part 51 thins inputted picture data of noncorrection by a mask pattern shown by the sent mask control signal. When a toner saving function is selected, the part 52 composites data on the correction object pixel of the edge part of correction data and thinned picture data and outputs it to a printer engine 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus such as a laser printer and a digital copying machine, and more particularly to a method for reducing the consumption of toner and ink.

[0002]

2. Description of the Related Art For example, when a digital copying machine or the like is used to form and print an image such as a color image that requires high quality image quality, usually, test printing is repeated to obtain a beautiful and good image quality. After confirming the fact, it is common to actually perform printing. When forming such a test print or an image having such a high quality, a toner saving function for thinning out print pixels is employed to suppress the amount of toner used.

[0003]

In the above-mentioned conventional toner save function, since the printing pixels are thinned out at a predetermined fixed ratio, the image quality is sometimes deteriorated and the formed image becomes difficult to see.

[0004] It is an object of the present invention to improve such disadvantages and to obtain a printing apparatus capable of suppressing the amount of toner used without deteriorating image quality.

[0005]

A printing apparatus according to the present invention detects an edge portion of an image from input bitmap image data, and performs image processing such as smoothing if necessary. For the performed pixels, the image data after correction is output, and the image data not to be corrected is thinned out with reference to a mask pattern selected according to the input image data, and is output.

A second printing apparatus according to the present invention is a printing apparatus which detects an edge portion of an image from input bitmap image data and performs image processing such as smoothing if necessary. Is characterized in that the corrected image data and the image data not to be corrected are combined, and the combined image data is thinned out with reference to a mask pattern selected in accordance with the input image data and output.

It is preferable to arbitrarily set a mask pattern for thinning the image data.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing apparatus according to the present invention has an image data input unit, an image buffer, an image correction unit, a toner save control unit, an output image selection unit, and a printer engine. A plurality of types of mask pattern data indicating mask patterns for thinning out pixels of image data are stored in the toner save control unit in advance. The output image forming unit has a mask control unit and an image selecting unit.

When image data is input to the image data input unit from a host device or the like, the input image data is temporarily stored in an image buffer. The image correction unit determines a correction target pixel of an edge portion from the bitmap image data stored in the image buffer, performs a correction process such as an edge smoothing process, and indicates whether to output the correction data and the correction data. The data selection signal is sent to the image selection unit of the output image forming unit. On the other hand, the toner save control unit selects mask pattern data according to the input image data, and sends a mask control signal indicating the selected mask pattern to the mask control unit of the output image forming unit. The mask control unit thins out the uncorrected input image data according to the mask pattern indicated by the transmitted mask control signal, and sends the thinned image data to the image selection unit. When the output of the correction data is selected by the correction data selection signal transmitted from the image correction unit, the image selection unit outputs the correction data transmitted from the image correction unit to the printer engine. When the output of the correction data is not selected by the correction data selection signal, that is, when the toner save function is selected, the data of the correction target pixel at the edge portion of the correction data and the thinned image data are combined and output. Output to the printer engine as image data. The printer engine prints and outputs an image based on the sent output image data.

In this way, when correction data is selected, an image thinned out by a mask pattern corresponding to image data is output, so that the amount of toner used can be suppressed without deteriorating image quality.

[0011]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. As shown in the figure, the printer device includes an image data input unit 1 for inputting image data created by a host device or the like, an image buffer 2 for temporarily storing the input image data, an image correction unit 3, and a toner save control unit. 4, an output image selection unit 5 and a printer engine 6. The image correction unit 3 inputs the input image data stored in the image buffer 2 to determine a pixel to be corrected, performs a correction process such as an edge smoothing process on the pixel to be corrected, and outputs a correction data and a correction data selection signal to select an output image. Output to section 5. The toner save control unit 4 includes a pattern input unit 41, a mask pattern storage unit 42, a vertical synchronization signal input unit 43, a horizontal synchronization signal input unit 44, an image clock input unit 45, and a mask data selection unit 46. The pattern input unit 41 inputs mask pattern data as a reference when performing the toner save process, and arbitrarily changes the value of the input mask pattern data. A plurality of types of mask pattern data indicating mask patterns for thinning out pixels of image data are stored in the mask pattern storage unit 42 in advance. The mask selection unit 46 uses a vertical synchronization signal of image data input from the vertical synchronization signal input unit 43, a horizontal synchronization signal input from the horizontal synchronization signal input unit 44, and an image clock input from the image clock input unit 45 to store the mask pattern storage unit 42. And outputs a mask control signal to the output image selection unit 5. Output image selector 5
Has a mask control unit 51 and an image selection unit 52. The mask controller 51 thins out the uncorrected input image data stored in the image buffer 2 according to the mask control signal output from the mask data selector 46 and outputs the thinned image data to the image selector 52. The image selection unit 52 selects output image data from the correction data and the thinned image data based on the correction data selection signal input from the image correction unit 3 and outputs the output image data to the printer engine 6.

The operation of printing image data input by the printer constructed as described above will be described with reference to the flowchart of FIG.

When image data is input from the host device or the like to the image data input unit 1, the input image data is temporarily stored in the image buffer 2 (step S1). The image data stored in the image buffer 2 is sent to the image correction unit 3 and the mask control unit 51 of the output image selection unit 5 as bitmap image data. The image correction unit 3 determines a correction target pixel of an edge portion from the transmitted bitmap image data, and performs a correction process such as an edge smoothing process.
The correction data and a correction data selection signal indicating whether to output the correction data are sent to the image selection unit 52 (step S2).
On the other hand, the mask selection unit 46 of the toner save control unit 4 uses the vertical synchronization signal and the horizontal synchronization signal of the image data and the image clock to store the mask pattern data stored in the mask pattern storage unit 42, for example, as shown in FIG. The data of the mask pattern 7 constituted by a pattern for thinning out the pixels of each pixel is selected, and a mask control signal indicating the selected mask pattern is sent to the mask control unit 51 (step S3). The mask controller 51 thins out the uncorrected input image data input from the image buffer 2 using the mask pattern indicated by the sent mask control signal, and sends the thinned image data to the image selector 52 (step S4). For example, when the mask pattern 7 shown in FIG. 3 is selected,
As shown in FIG. 4, the input image 8 is thinned out by the mask pattern 7 to obtain a thinned image 9. When the output of the correction data is selected by the correction data selection signal transmitted from the image correction unit 3, the image selection unit 52 outputs the correction data transmitted from the image correction unit 3 to the printer engine 6 (step S5). , S6). When the output of the correction data is not selected by the correction data selection signal, that is, when the toner save function is selected, the data of the correction target pixel at the edge portion of the correction data and the thinned image data are combined and output. The data is output to the printer engine 6 as image data (steps S5 and S7). The printer engine 6 forms an image based on the output image data sent, forms a toner image on printing paper, and outputs it (step S8).

In this way, when the correction data is selected, an image thinned out by a mask pattern corresponding to the image data is output, so that the amount of toner used can be suppressed without deteriorating the image quality. In addition, since the data of the pixel to be corrected at the edge portion of the correction data and the thinned image data are combined to obtain output image data, as shown in FIG. A reduced output image 10 can be obtained. Therefore, it is possible to reduce the amount of toner used and form a high-quality image.

Further, since the value of the mask pattern data stored in the mask pattern storage section 42 can be arbitrarily changed by the pattern input section 41, the mask pattern and the image quality of character or image image data are not impaired. In addition, it is possible to select and save a mask pattern in which the amount of toner used is suppressed.

In the above embodiment, the case where the image data thinned out by the mask control unit 51 of the output image selection unit 5 is sent to the image selection unit 52, but the pixel to be corrected in the edge portion is corrected by an edge smoothing process or the like. An embodiment will be described in which the data of the corrected pixel subjected to the processing and the uncorrected input image data are combined and then the thinning processing is performed.

In the case of this embodiment, as shown in the block diagram of FIG. 6, an image selection section 52 is provided at a stage preceding the mask control section 51 of the output image selection section 5. Image selection unit 52
When the output of the correction data is selected by the correction data selection signal sent from the image correction unit 3, the correction data sent from the image correction unit 3 is sent to the mask control unit 51. The mask control unit 51 outputs the sent correction data to the printer engine 6 as it is. When the output of the correction data is not selected by the correction data selection signal, the data of the correction target pixel subjected to the correction processing such as the edge smoothing processing of the correction data sent from the image correction unit 3 and the input of the non-correction input. The image data is synthesized and sent to the mask control unit 51. The mask control unit 51 thins out the synthesized image data using a predetermined mask pattern, and outputs the thinned image data to the printer engine 6. In this manner, by thinning out the image data obtained by combining the data of the correction target pixel and the uncorrected input image data, the thinning processing can be performed at the same ratio in all the regions of the image regardless of the outline of the image.

[0018]

As described above, according to the present invention, when the input image data is printed and output, if the toner save function is selected, an image thinned out by a mask pattern corresponding to the image data is output. The amount of toner used can be suppressed without deteriorating image quality.

Also, since the data of the pixel to be corrected at the edge portion of the correction data and the thinned image data are combined to form output image data, the output image in which the outline of the input image is clarified and the amount of toner used is reduced can be obtained. Thus, the amount of toner used can be reduced, and a high-quality image can be formed.

Further, by arbitrarily changing the value of the mask pattern data for thinning out the input image data, a mask pattern which does not impair the image quality of the character or image image data or a mask pattern which suppresses the amount of toner used. Can be selected, and the amount of toner used can be suppressed without deteriorating the image quality.

Further, by combining the corrected image data of the pixels subjected to the image correction and the image data not to be corrected and thinning out the synthesized image data, the same image is obtained in all regions of the image regardless of the outline of the image. The thinning process can be performed at a ratio, and the amount of toner used can be further reduced.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a configuration diagram of a mask pattern.

FIG. 4 is an explanatory diagram showing an image thinned out by a mask pattern.

FIG. 5 is an explanatory diagram showing an output image in which each contour of an input image is clarified.

FIG. 6 is a block diagram showing a configuration of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image data input part 2 Image buffer 3 Image correction part 4 Toner save control part 5 Output image selection part 6 Printer engine 41 Pattern input part 42 Mask pattern storage part 46 Mask data selection part 51 Mask control part 52 Image selection part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 1/409 H04N 1/40 101D

Claims (3)

[Claims] 1. A printing apparatus which detects an edge portion of an image from input bitmap image data and performs image processing such as smoothing as necessary, outputs corrected image data for pixels for which image correction has been performed. A printing apparatus characterized in that image data not to be corrected is thinned out with reference to a mask pattern selected according to the input image data and output. 2. A printing apparatus for detecting an edge portion of an image from input bitmap image data and performing image processing such as smoothing as necessary, wherein the corrected image data of a pixel subjected to image correction and a correction target A printing apparatus that combines outside image data, thins out the combined image data with reference to a mask pattern selected according to the input image data, and outputs the thinned image data. 3. The printing apparatus according to claim 1, wherein a mask pattern for thinning the image data is arbitrarily set.