JPH03217170A - printing device - Google Patents

Abstract

PURPOSE:To achieve a multicolor expression and high resolution with the small source of a memory by changing resolution according to the number of colors to be used. CONSTITUTION:The designated number of colors is set to a color number designation flag 6a and according to the new color designation, usable maximum resolution dmax is calculated. Out of the resolution provided for a printer, the closest resolution less than the maximum resolution dmax is selected and set to the resolution flag 6a. Next, the number of dots in the longitudinal and lateral sides of a frame is determined and set to a frame buffer area 6c. Thus, for a part requiring the high resolution in the single color like a character, the quality can be prevented from being degraded by reducing the color number designation and increasing the resolution, and at an image or graphic part, the memory can be prevented from being increased by increasing the color number designation and lowering the resolution. Then, both the multicolor expression and the high resolution can be achieved with the small memory source.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printing device capable of performing multicolor printing and changing resolution.

[Prior Art] Conventionally, a multicolor printing apparatus has been required to have a frame memory for the number of colors to be printed, regardless of the resolution of the printout.

[Problem to be solved by the invention] However, in a printing device with high resolution,
Having frame memories for the number of printing colors requires a huge amount of memory capacity and increases costs.

Basically, color images and graphics parts that require multicolor expression do not require very high resolution, so there is a way to reduce memory by lowering the resolution, but parts such as characters that require high resolution However, a new problem has arisen in that the quality deteriorates.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and includes the following configuration as one means for solving the above-mentioned problems.

That is, a printing means capable of printing in two or more colors, a specifying means for specifying the number of colors to be printed by the printing means, and a resolution changing means for changing the resolution according to the number of colors specified by the specifying means. The printing means prints out the number of colors specified by the specifying means in accordance with the resolution changed by the resolution changing means.

[Effect] In the above configuration, by changing the resolution according to the number of colors used, for areas (or pages) that require high resolution with a single color such as text, the number of colors specified can be reduced and the resolution increased. This prevents deterioration of quality, increases the number of colors specified for images and graphics, and reduces memory capacity by lowering the resolution, making it possible to achieve both multicolor expression and high resolution with less memory resources. This is how it was done.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a printing apparatus having means for changing resolution and means for printing in multiple colors in one embodiment of the present invention.

In FIG. 1, an external host computer 2 is connected via a connector (not shown) to a main body 1 of the printing apparatus, which has means for changing resolution and means for printing in multiple colors, indicated by broken lines. It is configured to receive print commands, color number designation commands, etc. from the computer 2 and print them out.

In the main body 1 of the printing device, 3 is a program ROM 5 that stores the main unit 1 according to the control procedure shown in FIG. 2, for example.
4 is a receiving buffer for storing data received from the host computer 2 such as print commands and color number designation commands; 5 is a receiving buffer that stores programs for executing a series of control flows described above and later. ROM,
6 is a RAM that functions as a work area when the CPU device 3 executes a program, and this RAMG includes a color number flag area 6a that temporarily stores the designated number of colors.
, a resolution flag area 6b for temporarily storing the resolution according to the number of colors, a frame buffer of a size according to the resolution for the number of colors is temporarily secured, and print data according to the resolution for the number of colors is stored. A frame buffer area 6c is secured.

7 is 1 color (black), 3 colors (yellow, magenta,
cyan), if << is a 3-step color setting means of 4 colors (yellow magenta, cyan, black), and 200 d
pi, 2 4 0 dpi, if << is 3 of 400 dpi
The printing output unit has stepwise resolution changing means, and 8 is a power supply device that supplies operating power to each component. Note that the output section 7
Since the configurations of the color setting means and the resolution changing means are well known, a detailed explanation thereof will be omitted.

Next, the operation of the printing apparatus having the above-described configuration and the means for changing the resolution and the means for performing multicolor printing will be explained based on the flowchart of FIG. 2.

In FIG. 2, when power is supplied to the main body 1 and operating power is supplied from the power supply unit 8 to each component, the process shown in FIG. 2 is executed. First, in step S1, the color number designation flag 6a in the RAMG is initially designated as 1 (single black color). Subsequently, in step S2, the maximum usable resolution dmax is determined. d
max is {(capacity of frame buffer area 6C) ÷
(length x width) ÷ number of colors}, for example, if the frame size is A4 (effective printing area 8 inches x 10.8 inches)
inch), and if the size of frame buffer area 6C is 1.8 MB based on the storage capacity of RAM 6, then
Maximum usable resolution dmax is 1.8 x 102
It is determined by the square root of 4X l024X 8÷(8X10.8)÷1, and is determined to be 418.05.

Next, in step S3, the closest resolution below the maximum resolution dmax (for example, resolution d=400 in this embodiment) is selected from among the resolutions possessed by the printing device, and is set in the resolution flag 6b.

Subsequently, in step S4, the number of vertical and horizontal dots of the frame is determined and set in the frame buffer area 6C. In the above example, 8 inches x (resolution d) ÷ 8, and 10
．． 8 inches x (resolution d), horizontal x size = 400 (bytes), vertical y size = 43
The size of the frame buffer is determined to be 20 (dots), and a frame buffer for one color is set in the frame buffer area 6c.

Next, in step S5, data sent from the host computer 2 is received, and the received data is stored in the reception buffer 4. Then, data corresponding to one unit code is read from the received data stored in the reception buffer 4.

The data read in step S6 is the color number designation command.
It is determined which command is received, a normal print command or a paper discharge command. If the result of the determination is a color number designation command, the process advances to step S7, and it is determined whether the command is at the beginning of the paper. If it is not the beginning of the paper, ignore this command and step S
Return to 5.

On the other hand, if the number of colors designation command is at the beginning of the paper, the process advances to step S8, and the number of colors designated is one color (black), three colors (yellow, magenta, cyan), or four colors (yellow, magenta, cyan). , black). Then, the designated number of colors is set in the number of colors designation flag 6a. Then, in step S9, the maximum usable resolution dmax is determined according to the new color designation. For example, if three colors are specified, the frame size in this embodiment is A4 size as described above, and the size of the frame buffer area 6C is 1.8 MB, which is the maximum usable resolution. dmax is 1.8X 1024X
It is determined by the square root of 1024X8÷(8X10.8)÷3, and is determined to be 241.36.

Therefore, in the subsequent step SIO, the closest resolution below the maximum resolution dmax is selected from among the resolutions possessed by the printing apparatus, and is set in the resolution flag 6b. In this embodiment, d=240 is selected as the resolution, and the resolution flag 6
b. Next, in step Sll, the number of vertical and horizontal dots of the frame is determined, and the number of dots in the frame buffer area 6C is determined.
Set to . In the example above, 8 inches x (resolution d) ÷ 8, and 10.8 inches x (resolution d), the horizontal direction x size = 240 (bytes),
The size of the frame buffer in the vertical direction is determined as y size=25.92 (dots), and frame buffers of three colors are set in the frame buffer area 6C. Then, the process returns to step S5.

On the other hand, as a result of the command determination in step S6, if the received command is a paper ejection command, the process advances to step S20, and the color number information of the color number designation flag 6a, the resolution information of the resolution flag 6C, and the frame buffer 6c are stored. The stored received print data is transferred to the print output unit 7, and the process returns to step S5. The print output section 7 that receives this transfer feeds the recording paper and prints it out in the designated color and resolution using a known method.
Eject the printed recording paper.

On the other hand, if the result of the command determination in step S6 is a normal print command, the process advances to step S25, and the subsequently sent print data is sequentially stored in the corresponding frame buffer 6c, and storage of the print data is completed. Then, the process returns to step S5.

As explained above, according to this embodiment, by changing the resolution according to the number of colors used, the number of colors specified can be reduced for parts (or pages) that require high resolution with a single color such as text. By increasing the resolution, you can prevent deterioration in quality, increase the number of colors specified for images and graphics, and reduce the resolution to prevent an increase in memory. You can achieve both.

[Other Embodiments] In the above explanation, an example was described in which the number of colors is specified on a page-by-page basis, but the present invention is not limited to the above example. It may be controlled so that the specification can be changed.

1 2 Further, the designation of the number of colors may not directly correspond to the number of frame buffers as in this embodiment, but may be configured such that the number of frame buffers is designated indirectly via a color table or the like.

Furthermore, the color number designation command may be combined with a function designation command such as text/image/graphics.

Furthermore, the number of colors may be designated not only from the host computer 2, but also by manual input from a panel or the like.

The switching of the resolution is not limited to the stepwise method as described above, but may be configured to be able to be set continuously.

Alternatively, the format may be such that the number of colors is specified by a resolution specification command.

Furthermore, the frame buffer does not have to have the capacity of the entire page of recording paper, but may be a part of it.

[Effects of the Invention] As explained above, according to the present invention, by changing the resolution according to the number of colors used, the number of colors can be specified for parts such as characters that are monochromatic and require high resolution. By increasing the resolution, you can prevent deterioration in quality, and by increasing the number of colors specified for images and graphics, and by lowering the resolution, you can prevent an increase in memory. You can achieve both.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment according to the present invention, and FIG. 2 is an operation flowchart of the embodiment. In the figure, 1...Printing device main body, 2...Host computer, 3...CPU device, 4...Receiving buffer, 5
...Program ROM, 6...RAM, 6a...
Number of colors designation flag area, 6b...Resolution flag area, 6c...Frame buffer area, 7...Print output section, 8...Power supply device. E5

Claims (1)

[Claims] A printing means capable of printing in two or more colors, a specifying means for specifying the number of colors to be printed by the printing means, and a resolution changing means for changing the resolution according to the number of colors specified by the specifying means. A printing apparatus, wherein the printing means prints out the number of colors specified by the specifying means in accordance with the resolution changed by the resolution changing means.