JPH0431078A - Printing device - Google Patents

Abstract

PURPOSE:To prevent a recorded pattern from becoming damaged at the time of low image resolution by detecting whether a character or an image is damaged and switching to the high resolution mode, if damaged. CONSTITUTION:A pattern expansion part 24 expands a pattern in accordance with a character code or an image drawing command in a gape buffer 23. Data is expanded from the page buffer 23 into a frame buffer 25 as a single page pattern by a control part 21, using a pattern expansion part 24, and this pattern is printed out by a printer engine part 26. A tolerable range of ON/OFF switching times of a specific line is set for each character, and then the damage of characters is checked based on the number of the switching times of the specific line. If a recorded pattern is an image, its damage is likewise checked. Thus the character or image can be prevented from becoming damaged by detecting whether there is a damage on the character or image and switching to the high resolution mode, if damaged.

Description

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

[Prior Art] In conventional printing apparatuses of this type, once a viewing resolution is designated, the resolution cannot be changed until the designation is changed.

Therefore, if you specify a low resolution for the engine part that can switch resolutions, the printed characters will be patterned using a scalar pull font of a certain size (number of points).
Characters may be distorted. Furthermore, similar image distortion occurs in the development of an image pattern.

[Problems to be Solved by the Invention] The present invention provides a printing device that eliminates the above-mentioned conventional drawbacks and prevents the recorded pattern from being distorted regardless of the designated resolution.

[Means for Solving the Problem] In order to solve this problem, the printing device of the present invention is a printing device having an engine unit capable of selecting a resolution, and which develops a recording pattern according to a specified resolution. The apparatus includes a developing means, a collapse detecting means for detecting a collapse of the developed recording pattern, and a switching means for switching the resolution according to the detected result.

Here, the collapse detection means detects collapse of the recording pattern based on the number of times recording data of a specific recording line corresponding to the recording pattern is switched.

[Function] In such a configuration, when the recorded pattern is likely to be distorted, the resolution is changed to prevent blurring.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a printing apparatus according to this embodiment. In the figure, 1 is a host computer that transmits print data, etc., and 2 is a printing device of this embodiment.

The printing device 2 has the following components. 21 is a control unit that controls the entire printing apparatus, and the CPU 21 a
A ROM 21b for storing processing programs, font outline data, etc., and an auxiliary RAM 21c are provided. 22 is a resolution storage unit that stores the set resolution; 23 is a page buffer that stores internal data in page units; and 24 is a pattern expansion unit that performs pattern expansion according to the character code or image drawing command in the page buffer 23. Department. Reference numeral 25 denotes a frame buffer in which a pattern for one page is developed using the data in the page buffer 23 by the control section 21 using the pattern development section 24, etc., and the pattern developed here is printed by the printer engine section 26. Output/receive.

FIGS. 2(a) and 2(b) are examples of font pattern output at the time of resolution switching when the recording pattern is a character pattern. Figure 2 (a) and 150d are the font patterns for the character code 2422゛A'' when the character size is increased to 384 points (3,84/72 inches) and are developed in the font development section 24 at a resolution of 300 dpi.
FIG. 2(b) shows a pattern developed at a resolution of pi.

As a result of reading the outline data for the character code in the page buffer 23 from the ROM 2 lb and developing it into a pattern in the pattern development unit 24 according to the resolution of the resolution storage unit 22, at 150 dpi, the outline data shown in Fig. 2 (
As shown in b), the letters are clearly blurred.

In this embodiment, in order to detect this character collapse, the number of ON10FF switching of dots in a certain line is checked. In the 300 dpi inspection line in Fig. 2(a), 0FF-ON-OFF-ON-OFF-
〇N → OFF, and the number of switching is ``6'', but in the 150 dpi inspection line in Figure 2 (b), it is 0N-OFF-ON-OFF, and the number of switching is ``3''. For this reason, a permissible range of the number of ON10FF switching of a specific line is set for each character, and the blurring of characters is checked based on the number of switching of the specific line.

Similarly, if the recording pattern is an image, see Figure 3(a).
, (b), the image level is checked based on the number of ○N10FF switching of a specific line.

By the way, in order to check the number of ON/○FF switching of the above-mentioned specific line, line information and allowable switching range must be set. An example of the setting is shown below.

FIG. 4 shows an example in which font information to which the above information is added is stored in the ROM2 lb.

Note that images stored in font format, such as marks and symbols, are handled in the same way. Corresponding to the pattern coat 41, it is composed of an inspection line number 42 for checking the number of switching times, an allowable number of switching times 43, and pattern data 44. The inspection line number 42 for checking the number of switchings is preferably, for example, the number of the line with the largest number of switchings, or the number of the line that clearly represents the feature of the figure or character.

On the other hand, when a recording pattern is sent from the host computer 1, the pattern data 53 to be transmitted as shown in FIG.
It is sufficient to add the inspection line number 51 and the allowable number of reversals 52 to . In addition, the inspection line and the allowable number of switching times are automatically determined by scanning the transmitted pattern data, setting the line with the maximum number of switching as the inspection line, and determining the allowable number of switching times based on the number of switchings. Good too.

FIGS. 6(a) and 6(b) are flowcharts showing the flow of the processing program of the printing apparatus of this embodiment. Control unit 21
The CPU 21 a performs processing using the RAM 21 c according to this program stored in the ROM 2 l b. A more detailed explanation will be given below according to the flowchart. The flowchart shown in FIG. 6(a) shows the flow of storing data from the host computer 1 to the page buffer 23. In addition, FIG. 6(b) shows the page buffer 2.
Data reception is achieved by simultaneously performing these two processes, which show the flow of pattern development of the data of 3 to the frame buffer 25, and the process of printing out the bitmap of the frame buffer 25 to the dot printer engine unit 26, in parallel by the control unit 21. We aim to improve efficiency.

First, the flowchart of FIG. 6(a) will be explained. In step S61, one piece of data transmitted from the host computer 1 is read, and in step S62, it is checked whether the data is a resolution switching command. If it is a resolution switching command, the process advances to step S63, and after storing the set resolution in the resolution storage section 22, the process returns to step S61 to begin reading the next piece of data. If it is not a resolution switching command in step S62, the data is stored in the page buffer 23 in step S64, and then step S61
Return to , and read the next data.

The flowchart shown in FIG. 6(b) will be explained. First, in step S71, one data is read from the page buffer 23, and in step S72, the current resolution is stored in the resolution storage section 23.
In step S73, a font pattern forming the currently specified character size (number of points) or an image pattern with the currently specified number of dots is developed, and the developed record is read. Check whether the pattern is collapsed or not in Figures 4 and 5.
Check the number of ON/OFF switching of a specific line according to the information in the figure. As a result of the investigation, if the number of switching times is less than the allowable number, it is determined that the recorded pattern is distorted, and the process proceeds to step 875, where the resolution is changed to a higher resolution by changing the setting value in the resolution storage section 22 to a larger value. , the process returns to step S72 and the pattern development is redone.

If the pattern is not collapsed in step S74, the process advances to step S76, where the recording pattern developed in the pattern development section 24 is written to the frame buffer 25, and then
The process returns to step S7L and begins reading the next data.

As described above, in this embodiment, by detecting the blurring of characters or images and switching to a high resolution, it is possible to prevent the characters or images from becoming blurred.

In the above-mentioned embodiment, the number of ON/OFF switching on the dot line is used to detect the blurring of characters or -' images, but it is also possible to use ON (black) switching for all dots forming characters or images. Another method is to set a permissible range for the dot ratio and use this to detect blurred text or images.

Further, in this embodiment, the resolution storage section is made independent, but if it is incorporated into the page buffer 23, resolution switching in page units becomes possible even in internal processing of multitasking.

Further, in this embodiment, resolution switching is executed by a command in the data sent from the host computer 1, but a changeover switch or the like is provided in the printing device and connected to the control unit 21, and a resolution switching command is output by switch operation. You can also.

[Effects of the Invention] As explained above, the present invention provides a printing device that can prevent the recorded pattern from being distorted at low resolution by detecting the distortion of characters/images and switching to a high resolution. can.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the printing apparatus of this embodiment, and Figure 2 (a
), (b) are examples of the font pattern output when switching the resolution when the example is text, and Figures 3 (a) and (b) are examples of the font pattern output when changing the resolution when the example is an image. , FIGS. 4 and 5 are explanatory diagrams showing the structure of image information. FIG. 6 is a flowchart showing the processing program of the printing apparatus according to this embodiment. FIG. 6(a) shows the flow of storing data from the host computer to the page buffer, and FIG. 6(b) shows the flow of storing data in the page buffer. The flow of pattern expansion to the frame buffer is shown. In the figure, l... host computer, 2... printing device, 21... control unit, 21a... CPU, 21b...
・ROM, 21c・RAM, 22...Resolution storage section, 23...Page buffer, 24...Pattern development section, 25...Frame buffer, 26...Dot printer engine section 6 Figure 00dp 0dpi (b) Fig. 2 300dpi 0dpi (b) Fig. 4 Fig. 6 ( Fig. 6 (b)

Claims (2)

[Claims] (1) A printing device having an engine unit capable of selecting a resolution, comprising: pattern development means for developing a recording pattern according to a specified resolution; a collapse detection means for detecting collapse of the developed recording pattern; and switching means for switching the resolution according to a result of the determination. (2) The printing according to claim 1, wherein the collapse detection means detects the collapse of the recording pattern based on the number of times recording data of a specific recording line corresponding to the recording pattern is switched. Device.