JPH02263669A - Image forming device - Google Patents

Abstract

PURPOSE:To facilitate a processing of enlarging/reducing characters or graphics by a method wherein a resolving power setting means for variably setting the resolving power of an image to be formed, and in response to the output thereof the image is enlarged/reduced. CONSTITUTION:A main control part 103 issues dot data 115 in synchronism with a horizontal synchronizing signal 113 transmitted from a sensor 211 of a printer engine 106. At this time, in the printer engine 106, the rotating speed of a rotating mirror 205 is varied and, accordingly, the cycle of the horizontal synchronizing signal 113 and the rate of the dot data 115 are varied, whereby a horizontal resolving power can be changed. A vertical resolving power can be changed by varying the rotating speeds of a paper feed roller 217 for feeding paper and a photosensitive drum 208. With a higher horizontal resolving power, a character that is laterally enlarged can be printed. With a lower horizontal resolving power, a dot gap is decreased, and a character that is laterally reduced can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus such as a laser beam printer that prints characters using a dot pattern.

(Prior Art) A laser beam printer having a bitmap font as a built-in font has been known as one of this type of image forming apparatus. This laser beam printer is equipped with fonts that correspond to the size of characters to be printed.

(Problems to be Solved by the Invention) However, the conventional example described above has the disadvantage that a large capacity memory is required to provide characters of many sizes, leading to an increase in cost. Furthermore, in reality, it is extremely difficult to store a font of any size in memory due to memory capacity limitations.

SUMMARY OF THE INVENTION In view of the above-mentioned points, an object of the present invention is to provide an image forming apparatus that is configured to easily and inexpensively enlarge and reduce characters and figures.

[Means for Solving the Problems] An image forming apparatus according to the present invention includes a resolution setting means for variably setting the resolution of an image to be formed, and an enlargement or enlargement of the image in response to the output of the resolution setting means. It is equipped with processing means for performing reduction.

[For production]

According to the present invention, by providing an image forming device such as a laser beam printer with a means for making the resolution variable, even if the font memory has only a limited number of points, it can be enlarged or reduced to make it look like a font. It is designed to be able to reproduce characters and figures of various sizes, similar to a printer that has built-in fonts of various point numbers.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In this figure, 101 is a font memory, 102 is a memory that stores text information 111 sent from a host computer (not shown), 103 is a main control unit, 104 is an operation panel, 105 is a printer engine I/F unit, and 106 is a memory that stores text information 111 sent from a host computer (not shown). It is a printer engine with variable resolution.

FIG. 2 shows 106 in FIG. 1 in detail. In FIG. 2, 201 is a laser oscillator, 202 is a reflecting mirror, and 203 is a modulator. 205 is a polyhedral rotating mirror, which is rotated by the drive of a motor 206. 207 is an imaging lens. A photosensitive drum 208 forms an electrostatic latent image using a laser spot.

Furthermore, 209 is a charger, 210 is a cleaner, 212 is a developing device, 215 is a transfer device, 216 is a recording paper, 217 is a paper feed roller, and 21B is a fixing device.

Next, the operation of a laser beam printer which is an embodiment of the present invention will be explained.

When text information 111 sent from a host computer or the like (not shown in FIG. 1) is stored in the memory 102, the main control unit 103 converts the character symbol pattern for the input text information from the memory 102 or from the font. Referring to the memory 101, the printer engine I/F 10
Send to head 5 in a dot pattern. When the dot data has been stored, the main control unit 103 issues a print start command 114 to the print control unit (not shown) of the printer engine.
Output.

Upon receiving this command, the drum 208 starts rotating, and the drum 208 starts rotating.
A magnet 220 on a disc fixed coaxially with the vertical synchronizing signal 11 passes over the Hall element 214.
2 is sent to the main control section 103.

This vertical synchronization signal 112 is output at the timing when printing is performed from the leading edge of the paper 216 when dot data 115 is output to the printer engine 106 after the signal is received.

The main control unit 103 sends out dot data 115 in synchronization with a horizontal synchronization signal 113 sent from a sensor 211 of the printer engine. The dot data 115 sent to the printer engine 106 is converted into a laser ON-OFF signal by a modulator 203, and is scanned onto a photosensitive drum 208 by a polygon mirror 205 to generate an electrostatic latent image. The electrostatic latent image generated on the photosensitive drum 208 is visualized by a developing device 212 according to a known electrophotographic process, and then fixed onto a recording paper 218 by a transfer device 215 and output as a hard copy.

In the printer engine 106, it is possible to change the resolution in the horizontal direction by changing the rotational speed of the rotating mirror 205 and changing the period of the horizontal synchronizing signal 113 and the rate of the dot data 115 accordingly. Regarding the resolution in the vertical direction, the paper feed roller 2 that conveys the paper
This can be changed by changing the rotational speeds of the photosensitive drum 17 and the photosensitive drum 208.

Now, suppose that the character data "A" as shown in Figure 3 exists on the font memory 101 (the "mouth" in the figure
Suppose that corresponds to a dot).

When the horizontal resolution is increased, characters enlarged in the horizontal direction can be printed as shown in FIG. The “ward” in the figure indicates the dot data that is output when the dot spacing is too large (
It is assumed that the main control unit 103 outputs "ward" dot data based on the resolution).

When the resolution in the horizontal direction is lowered, the dot spacing becomes narrower, resulting in characters that are shrunk in the horizontal direction, as shown in FIG. 5 (the "-" in the figure indicates overlapping dots).

FIG. 6 and FIG. 7 are examples in which the resolution in the vertical direction is changed.

FIG. 8 is an example in which the resolution in both the horizontal and vertical directions is increased.

By changing the resolution of the printer 106 as described above, characters can be enlarged or reduced.

When characters are enlarged or reduced by changing the resolution of the look-alike GM decoy printer engine 106, problems arise such as too much space between dots and dot data overlapping. Therefore, if the dot spacing is too empty, the main control unit 103 creates data to fill the gap, or if the dots overlap, it reduces the dot data.

In particular, the operation of outputting data to fill in gaps between dots can be set via the operation panel. In addition, if characters are crushed due to reduction, a message indicating that printing is not possible is displayed on the operation panel or the like.

〔Effect of the invention〕

As explained above, by providing an image forming device such as a printer with a means to change the resolution, characters can be enlarged or reduced using the built-in font memory, resulting in the following effects. be.

(1) There is no need to store characters with a number of points in the memory as in the conventional case.

(2) Since the memory capacity can be reduced by the above (1), the cost can be reduced.

(3) The memory freed by (1) above can be used effectively.

(4) Although the quality of characters and graphics is somewhat inferior, it has the same effect as having a non-bitmap font in memory.

[Brief explanation of drawings]

Figure 1 is a block diagram of a printer that is an embodiment of the present invention, Figure 2 is a configuration diagram of a printer engine, Figure 3 is a diagram showing character dot data (part 1), Figure 4 is character dot data. Figure 5 shows the character dot data (Part 3), Figure 6 shows the character dot data (Part 4), Figure 7 shows the character dot data (Part 4), and Figure 7 shows the character dot data (Part 4). 5). FIG. 8 is a diagram showing character dot data (Part 6). 101... Font memory, 102... Memory, 103... Main control unit, 104... Operation panel, 105... Printer engine I/F. 106...Variable resolution printer engine, 111...
- Text information, 112... Vertical synchronization signal, 113... Horizontal synchronization signal, 114... Print start signal, 115... Dot data. Figure Broom Figure Figure Figure

Claims (1)

[Claims] 1) A resolution setting means for variably setting the resolution of an image to be formed, and a processing means for enlarging or reducing the image in response to the output of the resolution setting means. An image forming apparatus characterized by: