JPH04320863A - Printer - Google Patents

Abstract

PURPOSE:To enable printing output information including a character and a graphic to be outputted in high quality without causing deterioration of image quality of an image data. CONSTITUTION:The title printer is structured as follows: when image information exists, a resolution selective means (a highest resolution selective means 102) compares image resolution information to be assigned by printing information to be inputted with set resolution information, selects automatically a settleable optimum printing output resolution: a setting means (a control mechanism 107) changes resolution of a printing mechanism to be settled according to the selected resolution: a printing data developing means 103 bit-map developes the received printing information based on the resolution selected by the resolution selective means.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and particularly to a printing apparatus that performs printing processing by creating bitmap information for each page from data received from an external device, such as a host computer.

0002

2. Description of the Related Art Conventionally, this type of printing apparatus includes a controller section that receives and processes print data from a host computer, converts it into a video signal, and sends the video signal to a printing mechanism section (printer engine). It consists of a printing mechanism section (printer engine) that uses the video signal sent from the controller section to form a visible image on paper (plain paper) using an electrophotographic process and outputs it. Based on the print data received from the host computer (character code, figure, image, print position, size specification, etc.), print information for one page is developed as a bitmap in the image memory according to the resolution of the printer engine, Print output is obtained by converting the expansion result of the image memory into a video signal and transmitting it to the printing mechanism section.

[0003] Furthermore, the printing mechanism section operates a paper feed conveyance system in the printer engine based on control information from the controller section, and at the same time operates a video signal transmitted from the controller section using a laser beam, an LED array, etc. ，
An image is formed on a photosensitive drum using a photosensitive agent such as toner using a light-emitting element such as a liquid crystal shutter, and the formed image is transferred to paper (plain paper) fed by a paper feed conveyance system. ) is configured to use a high-temperature, high-pressure fixing device to obtain stable printing results.

[0004] In the printing apparatus configured as described above,
When the controller section develops print data sent from the host computer into a bitmap, it is common to develop it in accordance with the resolution of the printer engine.

Therefore, if image data is included in the print data and the resolution of the image data does not match the resolution of the printer engine, the image data is enlarged/reduced to match the resolution of the printer engine. The common method is to match the

[0006]

[Problem to be solved by the invention] When the resolution is corrected by enlarging/reducing the image data in this way,
There was a problem in that the image quality after correction was worse than the original image data.

The present invention has been made in order to solve the above-mentioned problems.The present invention has been made in order to solve the above-mentioned problems. Furthermore, by developing characters, figures, etc. according to the resolution of the set printer engine, it is possible to output high-quality print information including characters and figures without causing any deterioration in the image quality of the image data. The purpose is to obtain a printing device.

[0008]

[Means for Solving the Problems] A printing device according to the present invention compares image resolution information specified by input print information with set resolution information to determine the optimum print output resolution that can be set. resolution selection means for automatically selecting;
A setting means for switching and setting the resolution of the printing mechanism according to the resolution selected by the resolution selection means, and a print data development means for developing a bitmap of printing information based on the resolution selected by the resolution selection means are provided. It is something that

[0009]

[Operation] In the present invention, print information input from an external device is analyzed, and if image information exists,
The resolution selection means automatically selects the most suitable print output resolution by comparing the image resolution information specified by the input print information with the set resolution information, and the setting means automatically selects the optimum print output resolution according to the selected resolution. to switch and set the resolution of the printing mechanism, and the print data development means develops the received print information into a bitmap of the print information based on the resolution selected by the resolution selection means, and prints the received print information at the optimal resolution. make it possible to

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic block diagram showing the functional configuration of a printing apparatus according to an embodiment of the present invention.

In the figure, reference numeral 101 indicates a print data receiving section for receiving print data transmitted from a host computer. Here, the print data includes character codes, data such as figures and images, and print data that specifies the print position, size, etc. for actually performing the print process, and print data for the print mechanism (printer engine). It consists of control data. The control data is, for example, control data that specifies switching control of paper feeding mode (cassette paper feeding, manual paper feeding). 102 is an optimum resolution selection means;
Among the print data received by the print data receiving unit 101, the resolution of the image data is analyzed and the optimum resolution is set for the printer engine. Reference numeral 103 denotes print data development means, which develops the print data that has passed through the print data receiving section 101 into bitmap information for one page as output data in accordance with the resolution set by the optimum resolution selection means 102. The above 101 to 103 constitute a controller 104 of the printing apparatus.

Reference numeral 105 denotes an actual printing mechanism unit (printer engine), which is composed of a printing mechanism 106 and a control mechanism 107 for switching resolution.

[0013] In the printing apparatus configured as described above,
Print information input from an external device (host computer in this embodiment) is analyzed, and if image information exists, resolution selection means (optimum resolution selection means 102)
automatically selects the most suitable print output resolution by comparing the image resolution information specified in the input print information with the set resolution information, and the setting means (control mechanism 107) selects the selected resolution. The resolution of the printing mechanism is switched and set according to the resolution, and the print data development means 103 performs bitmap development of the received print information based on the resolution selected by the resolution selection means, and the received print information is optimized. Enables printing at high resolution.

FIG. 2 is a schematic diagram showing an overview of the hardware configuration of the printing apparatus shown in FIG. 1. As shown in FIG.

In the figure, 201 is a host computer for transmitting various print data to the printing device;
Reference numeral 2 denotes a main body of the printing apparatus, for example, in the case of a printing apparatus using a laser beam. 203 is a video controller, 20
4 is a printer engine (printing mechanism section); 205 is a control section that controls the entire inside of the printing mechanism section 204; it receives video signals from the video controller 203 and receives control commands from the video controller 203; It consists of a part that receives and sends the engine status to the video controller 203, and a part that controls the electrophotographic process, paper feed conveyance system 207, and optical system 206.

FIG. 3 is a perspective view of essential parts of an example of the paper feed conveyance system 207 shown in FIG. 2. As shown in FIG.

In the figure, numeral 301 indicates a paper feed cassette, and a paper feed roller 302 is driven to convey paper 305 in the direction of the arrow. 303 is a photosensitive drum for conveying paper 3;
05 to transfer the developed image. 304 is a fixing device;
After the toner image transferred to the paper 305 is fixed on the paper 305 by heat and pressure, the paper is discharged outside the machine.

FIG. 4 is a block diagram showing the detailed configuration of video controller 203 shown in FIG. 2. As shown in FIG.

In the figure, 401 is a CPU that controls the entire video controller 203, and controls each device connected to an internal bus 409 based on a control program stored in a program memory 402 composed of, for example, ROM (read-only memory). control overall. A font memory 403 is composed of, for example, a ROM (read only memory), and stores font data for developing a font corresponding to a character code into a bitmap. A work memory 404 is composed of, for example, a RAM (random access memory), and stores data, control flags, etc. necessary for program operation. A data input interface 405 interfaces data input between the host computer 201 and the video controller 203 . Reference numeral 406 denotes an image memory composed of, for example, a RAM (random access memory), which expands and stores a bitmap for one page from print data.

A data input/output interface 407 interfaces input/output data between the video controller 203 and the printing mechanism section 204. An image signal generator 408 generates a video signal from the image memory 406 in synchronization with the printing mechanism section 204.

FIG. 5 is a flowchart showing an example of the resolution switching processing procedure in this printing apparatus. (1) ~
(8) indicates each step (the page development process of the printing apparatus at the time when print data for one page is transmitted from the host computer 201).

First, it is checked whether image data exists in the page (1), and if it does not exist (N
O) sets the resolution of the printer engine to the default value (for example, 240 DPI) (2), and then performs step (7).
) Proceed to the following.

If image data exists in the page (YES), it is checked whether it is possible to set a resolution for the printer engine that matches the resolution of the image data (3), and if it is settable ( If YES), the resolution of the image data is set to the resolution of the printer engine (for example, 400 DPI) (4), and the process proceeds to step (7) and subsequent steps.

On the other hand, if it is determined in step (3) that it is not possible to set the printer engine to a resolution that matches the resolution of the image data (NO), the optimal resolution for the image data (for example, 300 DPI) is selected (5). )
.

[0025] Here, the optimal engine resolution for image data varies depending on the enlargement/reduction logic of the image data, and is as follows, for example.

Generally, the resolution IDPI of image data
If the resolution EDPI of the engine and engine are different, the resolution ID
Ratio between PI and resolution EDPI (IDPI/EDPI)
However, if the resolution is selected so as to satisfy the following equation (1), the deterioration in the image quality of the image data will be small.

For expansion: IDPI/EDPI=(n+1)
/n (n is a positive natural number) For reduction: ID
PI/EDPI=n/(n+1) (n is a positive natural number)

(1) If the above conditions do not apply, select a resolution as shown in equation (2) below.

IDPI/EDPI=m/n (n, m
is a positive natural number) ...(2) Next, the above step (
4) Alternatively, the resolution determined in step (5) is set in the engine (6), and character data, graphic data, image data, etc. for one page are developed into a bitmap according to the set resolution (7). Next, the expanded bitmap data is output to the printing mechanism unit 204 and printed out (8).

In the above embodiment, the resolution of the engine is determined by considering the resolution of the image data as the first priority, but the host computer 201
It may be configured such that a command can be used to instruct whether to give first priority to the resolution of the image data or to give first priority to the default resolution of the engine.

[0030]Furthermore, the printer may be configured to use a command from the panel operation unit of the printing apparatus to instruct whether to give first priority to the resolution of the image data or to give first priority to the default resolution of the engine.

[0031]

[Effects of the Invention] As explained above, the present invention automatically selects the optimum print output resolution that can be set by comparing the image resolution information specified by the input print information and the set resolution information. resolution selection means; setting means for switching and setting the resolution of the printing mechanism according to the resolution selected by the resolution selection means; and print data for bitmap development of print information based on the resolution selected by the resolution selection means. Since a development means is provided, the optimal resolution for the image information can be automatically set for the printing mechanism, preventing deterioration of the image quality of the image information and outputting high-quality printed information including characters, graphics, etc. Make the most of your efforts.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing the functional configuration of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an overview of the hardware configuration of the printing apparatus shown in FIG. 1;

FIG. 3 is a perspective view of essential parts of an example of the paper feed conveyance system shown in FIG. 2;

FIG. 4 is a block diagram showing the detailed configuration of the video controller shown in FIG. 2;

FIG. 5 is a flowchart illustrating an example of a resolution switching processing procedure in the present printing apparatus.

[Explanation of symbols]

101 Print data receiving section 102 Optimal resolution selection means 103 Print data expansion means 104 Controller 105 Printing mechanism section 106 Printing mechanism 107 Control mechanism

Claims (1)

[Claims] Claim 1: In a printing device equipped with a printing mechanism that analyzes printing information input from an external device and performs printing processing based on bitmap-developed printing data, an image specified by input printing information. resolution selection means for automatically selecting a settable optimal print output resolution by comparing resolution information and set resolution information; and switching the resolution of the printing mechanism according to the resolution selected by the resolution selection means. 1. A printing apparatus comprising: a setting means for setting; and a print data development means for developing a bitmap of the print information based on the resolution selected by the resolution selection means.