JPH04312863A - Printer device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to printer devices such as laser printers.

0002

[Prior Art] Printers currently in use generally have a fixed resolution, and when emulating a resolution different from that resolution, printing is performed by scaling and correcting image data using software or hardware. I am doing it. Also, some printer devices can support multiple resolutions, but if the printer engine supports a resolution that is an integer multiple of the emulation resolution, this printer engine is set to that resolution, and if it is not supported, it is already set. Printing is performed at the specified resolution.

0003

However, when emulating the graphic mode of a 120 DPI dot printer in the former type of printer device, for example a 300 DPI laser printer, one dot is divided into 2.5
Since the output must be doubled (300/120), a correction of 0.5 dots is required, and depending on the correction method, even if a high-resolution printer is used, the image quality may be lower than that of a low-resolution dot printer. In some cases, the quality was inferior. Moreover, most of the processing time may be spent on the correction.

[0004] In the latter printer device, if the printer engine does not support a resolution that is an integral multiple of the emulation resolution, printing will be performed at the already set resolution, so the printer engine will print at a higher resolution. Even if it supports , it does not necessarily print at that resolution. Therefore, the functions of the printer engine may not be utilized effectively.

[0005] The present invention has been made in view of the above points, and an object thereof is to solve the above-mentioned problems and to make it possible to obtain high-quality images.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a printer device that is capable of selecting at least two or more resolutions during printing. Emulation of A1 ~A
an emulation selection means B for selecting the emulation, and a resolution selection means C for selecting the resolution according to the emulation selected by the means B;
It has been established that

[0007] Furthermore, as shown in the functional blocks in FIG.
a resolution comparison and determination means D that compares the resolution of the selected emulation and the resolution supported by the printer device and determines whether the two match; and the resolution of the emulation selected by the means D. The present invention also provides a resolution selection means E for selecting a resolution higher than the resolution of the emulation selected as the resolution of the printer device when it is determined that the resolution compatible with the printer device does not match.

Further, the resolution selection means E may select the resolution of the printer device so that when the resolution of the printer device is divided by the resolution of the selected emulation, the remainder is minimized. desirable.

[0009]

[Operation] According to the printer device of the present invention, a resolution suitable for the selected emulation is selected, so a high quality image can be obtained.

[0010] Furthermore, when the resolution of the selected emulation and the resolution supported by the printer device do not match, by selecting a resolution higher than the resolution of the selected emulation as the resolution of the printer device, the image Data correction becomes easier.

In this case, high quality image data can be obtained by selecting the resolution of the printer so that the remainder is minimized when the resolution of the printer is divided by the resolution of the selected emulation. , the functions of the printer engine can be effectively utilized.

0012

[Embodiment] An embodiment of the present invention will be specifically described below with reference to FIG. 3 and subsequent figures. FIG. 3 is a block diagram showing the configuration of a laser printer embodying the present invention. This laser printer 1 is composed of a printer controller 2, a printer engine 3, and an operation panel 4.

Among them, the printer controller 2 converts character data or image data from the host 20 into video data and transfers it to the printer engine 3. It also stores downloaded font data from the host 20 in the internal RAM, and controls printing positions, selects fonts, etc. using control commands.

The printer controller 2 includes interface circuits such as a host interface 5, a panel interface 6, a bus buffer 7, and an engine interface 8, a microcomputer (hereinafter referred to as "CPU") 9, a program ROM 10, a font ROM 11,
It is equipped with a RAM 12 and an option RAM 13. Note that the above-mentioned units are interconnected by bus lines 14 consisting of an address bus, a control bus, and a data bus.

The host interface 5 is an interface circuit for transmitting and receiving various control commands and data to and from the host 20, and selects one of various serial interfaces or parallel interfaces depending on the host to be connected. The panel interface 6 transmits display control data to and from the operation panel 4 and receives each key information.

The bus buffer 7 connects the font card 21 to the bus line 14 and is in charge of receiving font data. The engine interface 8 is the printer engine 3
Controls the transmission and reception of data such as commands and status information between the

[0017] The CPU 9 is a microprocessor, ROM
, RAM, I/O, etc., and is in charge of overall control of the entire printer. This CPU9 has a program ROM1
By using the control program stored in the host 20, various video data with different resolutions can be created based on control commands, character data, etc. transferred from the host 20.

The program ROM 10 stores a control program for operating the CPU 9, and the font ROM 11 stores resident font data.

The RAM 12 is a random access memory, and includes a working memory of the CPU 9, an input buffer for temporarily storing control commands and character data, etc. received from the host 20, and data processing based on the control commands, character data, etc. temporarily stored in the input buffer. A page buffer that stores page data to be created, a video buffer that temporarily stores video data created for each page based on the data on the page buffer and font data, etc., and downloaded font data received from the host 20 or from the font card 21. This is used for font files that store font data.

The option RAM 13 is, for example, a nonvolatile memory, and stores set mode information (print format, font selection, emulation selection, resolution selection, host interface selection, etc.),
Stores service information (error information, operation information, etc.).

The host 20 is a host machine such as an office computer, a personal computer, a word processor, a data processing device, or an image processing device, and sends corresponding control commands to the printer 1 in order to print document information etc. created here. and send character data, etc.

The operation panel 4 is equipped with various operation keys and displays for inputting and outputting various information.The font card 21 has a built-in RAM or ROM that stores optional font data. By inserting the font into a slot provided on the outer surface of the printer (not shown), printing can be performed using the font data.

The printer engine 3 is composed of a laser writing unit that optically scans an internal photoreceptor drum (not shown) with a laser beam modulated in accordance with video data, the photoreceptor drum, and various process equipment around the photoreceptor drum. It consists of a mechanism section consisting of an image forming unit, a paper transport section consisting of a pair of registration rollers, etc., and an engine driver that is a control section of the mechanism section.
The engine driver executes printing by controlling the sequential operations of the image forming unit and the paper transport section and the video modulation signal to the laser writing unit.

Next, processing related to the present invention by the printer controller 2 will be explained in detail. In addition, here, 2
It is assumed that three types of resolution can be selected: 40, 300, and 360 DPI. Further, it is assumed that the printers to be emulated are a 240 DPI printer and a 180 DPI printer. First, a case of emulating a 240 DPI printer will be described.

When emulation of a 240DPI printer is selected by a command from the host 20 or by the operation panel 4, the printer controller 2 checks the resolution supported by the printer engine 3, and instructs the printer engine to change the resolution to 240DPI. An instruction signal is sent to printer engine 3, and upon receiving the signal, printer engine 3 changes the resolution to 240 DPI.

As a result, the printer controller 2 can perform one-to-one processing on the graphic image data and downloaded font data from the host 20, and image quality similar to that of the actual machine can be obtained.

Next, the case of emulating a 180 DPI printer will be explained. When emulation of a 180 DPI printer is selected in the above manner, the printer controller 2 checks the resolution supported by the printer engine 3 side. In this case, 18
Since 0DPI is not supported on the printer engine 3 side, the printer controller 2 searches for a resolution that is an integral multiple of this resolution, selects 360DPI, and instructs the printer engine 3 to use 360DPI.

The graphic image data and download font data from the host 20 are divided into two dots.
Processing to make it into dots is required. In other words, it is necessary to extend one dot data from the host 20 by two dots in the main scanning direction and two dots in the sub-scanning direction on the printer controller 2 side. However, since the processing is multiplied by an integer, there is no image deterioration and an image similar to the actual image can be obtained.

[0029] For character data, high-quality images can be obtained by using an outline font or the like that does not depend on resolution. FIG. 4 shows the process from when the above emulation is selected until the resolution is instructed to the printer engine 3. In addition, RES. EML
is the emulation resolution, RES. ENG indicates the resolution supported by the printer engine 3.

Next, processing performed by the controller 2 that is different from the above will be explained. Note that here, 150,240
, 300, and 400 DPI can be selected. Also, the printer to be emulated is
One is 240DPI and the other is 180DPI.

[0031] The case of emulating a 240DPI printer is the same as described above, so here we use 18DPI.
Only the case of emulating a 0DPI printer will be described.

When emulation of a 180DPI printer is selected, the printer controller 2 selects one of the four resolutions supported by the printer engine 3.
Select a resolution higher than the selected emulation resolution, that is, a resolution other than 150 DPI. resolution is 2
If the type (for example, 150, 300 DPI), the processing ends here, but in this example, the algorithm described above
40, 300, 400 DPI are selected.

Therefore, in order to select one optimal resolution, the following calculation is performed. Printer resolution/emulation resolution Actually, 240/180 = 1 remainder 60 (1.33
333) 300/180 = 1 remainder 120 (1.66666) 40
0/180=2 remainder 40 (2.22222).

[0034] In other words, if 240DPI is selected, 1
Dots 1.33x (240/180), 300DPI
At 400DPI, the image must be enlarged 1.66 times, and at 400 DPI, it must be printed 2.22 times. However, since laser printers cannot print dots below the decimal point, some kind of correction is required. Here, an example of correction will be explained based on Table 1.

Table 1 shows how one dot of 180 DPI is corrected at each resolution. For example, for the first dot 240,300
The DPI is 1 dot, and 400DPI is 2 dots. The second dot is 1 dot at 240 DPI, and 2 dots at 300,400 DPI. By repeatedly performing such correction, image data with different resolutions can be obtained. Naturally, such a correction is
It is necessary to perform this not only in the main scanning direction but also in the sub-scanning direction.

[0036]

[Table 1]

As can be seen from Table 1, if the remainder of the above calculation formula (printer resolution/emulation resolution) is small, more accurate correction is possible. In other words, when emulating a 180 DPI printer, in this embodiment the resolution of the printer engine 3 is set to 4.
Optimum image quality can be obtained by setting it to 00DPI. FIG. 5 shows the process from when the above emulation is selected to when the resolution is instructed to the printer engine 3.

The embodiments in which the present invention is applied to a laser printer have been described above, but the present invention is not limited to this and can be applied to other printer devices such as LED printers and liquid crystal shutter printers, as well as digital copying machine printers. It is also applicable to departments, etc.

[0039]

As described above, according to the printer device of the present invention, when emulation is selected, a resolution suitable for the emulation is selected, so that high-quality images can be obtained. In addition, if the resolution of the selected emulation and the resolution supported by the printer device (printer engine) are different, the image data is corrected by selecting a resolution higher than the resolution of the selected emulation as the resolution of the printer device. becomes easier.

Furthermore, in that case, (printer resolution/
By selecting the resolution that minimizes the remainder value (emulation resolution), high-quality image data can be obtained and the functions of the printer device can be effectively utilized.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the basic configuration of the invention according to claim 1.

FIG. 2 is a functional block diagram showing the basic configuration of the invention according to claims 2 and 3.

FIG. 3 is a block diagram showing the configuration of a laser printer embodying the invention.

FIG. 4 is a flow diagram showing processing related to the present invention by the controller of FIG. 3;

FIG. 5 is a flow diagram showing processing different from that in FIG. 4 by the controller in FIG. 3;

[Explanation of symbols]

1 Laser printer 2
Printer controller 3 Printer engine 4
Operation panel 9 Microcomputer 10
Program ROM 11 Font ROM 12
RAM13 Option RAM
20 host 21 font card

Claims (3)

[Claims] 1. A printer device capable of selecting at least two or more resolutions during printing, comprising: emulation selection means for selecting one of the emulations, and a resolution according to the emulation selected by the means. A printer device comprising a resolution selection means for selecting a resolution. 2. A printer device capable of selecting at least two or more resolutions during printing, comprising emulation selection means for selecting one of the emulations and having a plurality of emulations, and a resolution of the emulation selected by the means. and a resolution compatible with the printer device to determine whether the two match or not, and the device determines whether the resolution of the selected emulation and the printer device are compatible. 1. A printer device comprising: resolution selection means for selecting a resolution higher than the selected emulation resolution as the resolution of the printer device when it is determined that the resolutions do not match. 3. The printer device according to claim 2, wherein the resolution selection means sets the resolution of the printer device so that when the resolution of the printer device is divided by the resolution of the selected emulation, the remainder is minimized. A printer device characterized in that it is a means for selecting.