JPH01297249A - Character output method and apparatus - Google Patents

Abstract

PURPOSE:To enhance the resolving power of output matter, by a method wherein the dot pitch in a sub-scanning direction is set so as to be smaller than that in a main scanning direction and a character is outputted while the ON-OFF modulation timing of beam is shifted at every one scanning line. CONSTITUTION:The pitch PV in a sub-scanning direction is set to 1/2 of the pitch PH in a main scanning direction. That is, this setting is achieved by setting the feed speed of a recording member to 1/2. Further, the timing at the time of ON-OFF of beam is shifted by a 1/2 cycle at every one scanning line at the time of main scanning to perform output. Each dot is outputted to such a position that the dot mounts on a lattice 7 of a pitch PHSin 45 deg. inclined by 45 deg. in dot positional relation. Therefore, when the bit data of a character pattern is prepared by decoding character pattern data storing the contour shape of a character, bit data must be prepared with respect to the point mounting on the lattice 7. In the even number-th scanning line and the odd number-th scanning line, the dots at different positions are thinned.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a character output method and device. Specifically, when outputting characters from a laser printer, etc., even characters composed of as few pixels as possible can be output. The present invention relates to a character output method and device for outputting high quality characters.

[Prior Art] A character output device such as a laser printer as shown in FIG. 2 converts a laser beam emitted from a laser light source 1 into an AOM <
The laser beam enters the acousto-optic modulator (acousto-optic modulator) 2 and performs ON/OFF control, and the rotating mirror 3 reflects the laser beam emitted from the AOM 2 to scan the recording member 4, thereby outputting characters or the like.

The data output at this time is ultimately developed as bit data in the bitmap memory.

At this time, scanning is performed in the horizontal direction (main scanning direction) by a laser beam, and scanning is performed in the vertical direction (sub-scanning direction) by feeding the recording member 4 in the direction of the arrow.

As a method for storing character patterns to be output, there is a method in which the shape of the outline of a character is stored in the form of a mathematical formula or the like, and characters of various sizes are decoded and output from one character pattern data. This is due to the fact that storing character patterns for each size as bit image data would require a huge amount of memory φ.

[Problems to be Solved by the Invention] When decoding and outputting characters from character pattern data stored using this method, large-sized characters require a large number of dots, so it is difficult to produce high-quality characters. Obtainable.

On the other hand, in the case of small-sized characters, the number of dots that make up the characters is small, so the characters must be expressed using fewer pixels.
It is extremely difficult to faithfully reproduce the original character outline shape by performing scaling processing (reduction processing in this case) on character pattern data represented by the shape of the character outline. When outputting low-pixel characters of the same small size, it is better to create and output character patterns manually to obtain higher quality characters. However, storing character pattern data as bit images for all sizes is problematic for the reasons mentioned above.

To solve this problem, it is possible to increase the density of the dots when outputting so that even small-sized characters can consist of as many dots as possible, but since there is a limit to the speed at which the beam can be modulated, the output There are various problems such as slow speed, increased bitmap memory capacity, and increased cost.

Further, the data of the bit image is expressed as points on a grid having the same pitch in both the main scanning direction and the sub-scanning direction. Therefore, since the connectivity in the main scanning direction and the sub-scanning direction is strong, the looseness of diagonal lines becomes particularly noticeable, which is also a factor in the deterioration of the quality of small-sized characters.

[Means for Solving the Problems] The present invention has been made based on the above points, and provides a character output method and device that can output characters with as high quality as possible even in small-sized characters composed of a low number of pixels. Its purpose is to provide a text output method that outputs text from a laser printer, etc., and its features include:
When the dot pitch in the main scanning direction is PH, the dot pitch Pν in the sub-scanning direction is set smaller than the pitch PH, and the timing of beam ON-OFF modulation is shifted for each scanning line to output. It is.

[Example] In the present invention, when outputting characters, when the pitch of dots in the main scanning direction is PH, the pitch of dots in the sub-scanning direction P
By setting V smaller than the pitch PH-+ and outputting by shifting the timing of ON/OFF modulation of the beam for each scanning line, high-quality characters can be output even with a low number of pixels.

Examples of the present invention will be described below.

In this embodiment (hereinafter referred to as the first embodiment), the pitch PV in the sub-scanning direction at the time of output is set to 1/2 of the pitch PH in the main-scanning direction. In other words, n. Setting the pitch PV in the sub-scanning direction to PH/2 is achieved by reducing the feeding speed of the recording member to 1/2 when PV=PH. Therefore, it can be seen that even with existing laser beam printers, it is possible to reduce the pitch in the sub-scanning direction to 1/2 simply by switching the feed speed.

Further, the timing when turning the beam on and off during main scanning is shifted by 1/2 period for each scanning line and output. FIG. 3 shows timing clocks 5a and 5b shifted by 1/2 period and scanning lines 6a and 6b at that time.

By alternately applying the timing clocks 5a and 5b for each scanning line, the ON/OFF timing of the beam is shifted by 1/2 period for each scanning line. In addition, here 1
Although the present invention is implemented by alternately applying timing clocks shifted by /2 periods, the present invention is not limited to this.
Of course, the ON-OFF timing may be shifted by 1/2 period for each scanning line using other methods.

Next, the creation of bit data when outputting under the above conditions will be explained. FIG. 4 shows the positional relationship of the dots when output under these conditions. As shown in Figure 4,
Each dot is tilted by 45', pitch P HSin
45''' grid 7. Therefore, when decoding the character pattern data that stores the shape of the outline of the character to create character pattern bit data, the grid 7 in FIG. Bit data must be created for the points listed in .The bit data is created, for example, as follows.

First, the pitch of dots in the main scanning direction when outputting is determined by PH.
When it is closed, as shown in Fig. 5 (1), the pitch P H
The bit data at the position on the /2 grid is decoded and obtained. Alternatively, the bit data at the position on the grid of pitch PH can be decoded into a size twice the output size. Both are substantially the same.

Thereafter, thinning processing is performed for every other dot. At this time, as shown in FIG. 5(2), dots at different positions are thinned out for even-numbered and odd-numbered scanning lines. In this way, bit data that is placed on a grid tilted by 45 degrees is created as shown in FIG. 5 (2). In addition, when developing the bit data created in this way in a bitmap memory, if the data of the even numbered or odd numbered scanning line is shifted by 1/2 pitch and the bit data is developed at the position as shown in FIG. 5 (3), - Even in-shell bitmap memory can be expanded without special address management and without requiring a large capacity bitmap memory.

When outputting bit data expanded to the bitmap memory, set the above-mentioned conditions, that is, the pitch in the main scanning direction to PH, the pitch in the sub-scanning direction to PV = Py/2, and as described above, set the pitch in the main scanning direction to PH = Py / 2, and output the bit data for each scanning line as described above. The modulation timing is shifted by 1/2 period and output.

Next, a second embodiment will be explained. In the second embodiment, as shown in FIG. 6, the output dot is output at a position equidistant from any of the six adjacent dots. In other words, it is output to a position on a lattice of series of equilateral triangles (hereinafter referred to as a triangular lattice). However, the bases of the equilateral triangles of the triangular lattice in the second embodiment are parallel to the main scanning direction.

For this purpose, when the pitch in the main scanning direction is PH, the pitch PV in the sub-scanning direction is set as PV=PH Sin 6G''.

Then, as in the first embodiment, the timing when turning the beam on and off is shifted by 1/2 period for each scanning line and output.

The data to be output is obtained by decoding the bit data at the points on the above-mentioned triangular lattice from the character pattern data.

The created bit data is developed into bitmap memory. FIG. 7 is a diagram showing the relationship between the bit data position on the triangular lattice (FIG. 7 (1)) and the position on the bitmap memory (FIG. 7 (■)) when it is expanded. As can be seen from FIG. 7, as in the first embodiment, the data of the even-numbered or odd-numbered scanning lines is shifted by 1/2 pitch and developed.

When outputting, set the pitch in the main scanning line direction to PH,! Set the pitch in the J scanning line direction to PV -PHSin soo,
The modulation timing is shifted by 1/2 period for each scanning line and output.

Next, a third embodiment will be described. In this example, the eighth
As shown in the figure, the output dot is output at a position equidistant from any of the six adjacent dots. In other words, it is output to a position on a triangular lattice, a lattice of series of equilateral triangles. However, the base of the equilateral triangle of the triangular lattice in this example is 30° from the main scanning direction.
It's leaning.

For this purpose, when the pitch in the main scanning direction is PH, the pitch PV in the sub-scanning direction is as follows.

Then, as in the previous embodiment, the timing when turning the beam on and off is shifted by 1/2 period for each scanning line and output.

The data to be output is obtained by decoding the bit data at the points on the triangular lattice mentioned above.

The created bit data is expanded in the bitmap memory, and the location in the memory when expanded is, for example, the location on the triangular lattice (FIG. 9 (1)) and the location in the bitmap memory (FIG. It is expanded to a position that shows the relationship shown in Figure 9 (2)). As in the previous embodiment, the data of even-numbered or odd-numbered scanning lines is shifted by 1/2 pitch.

When outputting, the pitch in the main scanning line direction is set to PH1, the pitch in the sub-scanning line direction is set to Pv=PH/2Tan60°, and the modulation timing is shifted by 1/2 period for each scanning line and output.

Next, the character output device of the present invention will be explained.

FIG. 1 is a block diagram showing an embodiment of the character output device of the present invention.

8; Output data storage section. Stores output data consisting of character codes of characters to be output, font information, typesetting information, etc.

9: Character pattern storage section. Character pattern data representing the shape of the outline of a character pattern in the form of a mathematical formula or the like is associated with a character code and stored for at least one typeface.

10; Bit data creation section. The character pattern data corresponding to the character code of the output data sent from the output data storage section 8 is read out from the character pattern storage section 9, and decoded to obtain the pit data pattern that appears on the grid shown in each of the above-mentioned embodiments. create.

11; Bitmap memory. The bit data creation section 1
The pattern decoded by o is bit-expanded.

12; Bitmap memory control unit. Various controls are performed when or after character patterns are developed in the bitmap memory 4.

13; Main scanning control section. ON-OFF control based on output bit data when scanning a laser beam,
Controls 0ff-OFF timing, etc.

14; Main scanning section. It is composed of a laser light source, an AOM, a polygon mirror, etc., and directs the laser beam to the main scanning controller 13.
The recording member is scanned according to the control of the recording member.

15; Sub-scanning control section. Controls the feeding speed of the recording member in the sub-scanning direction, etc.

16; Sub-scanning section. The recording member is sent in the sub-scanning direction under the control of the sub-scanning control section 15.

17; Recording member. A laser beam scans a photosensitive material, a photosensitive drum, etc. to record an image.

Next, the operation of the present invention will be explained.

First, the character code for one character, typesetting information such as font, character size, etc. are transferred from the output data storage unit 8 to the bit data creation unit 1.
Sent to 0. The bit data creation unit 10 reads character pattern data corresponding to the character code from the character pattern storage unit 9. The read character pattern data is decoded to the size according to the formatting information to obtain bit data.

At this time, the bit data of the points on the 45° inclined lattice or triangular lattice determined by the output conditions in each of the embodiments described above, that is, the pitch PH in the main scanning direction and the pitch PV in the sub-scanning direction is determined.

The bit data obtained in this way is stored in the bitmap memory 11 under the control of the bitmap memory controller 12.
Expand to.

Once the bit data is developed in the bitmap memory 11 in this way, the main scanning control unit 13 scans and outputs the developed bit data at pitch PH in the main scanning direction and with a 1/2 period timing shift for each scanning line. The main scanning section 14 is controlled so as to move the recording member 17 at a pitch PV, and the sub-scanning control section 15 controls the sub-scanning section 16 so that the recording member 17 is fed at a pitch PV.

By outputting as described above, it is possible to output so that each dot is placed on the grid shown in each of the above-mentioned embodiments.

[Effects of the Invention] As explained above, according to the present invention, the resolution of cutlery can be improved without doubling the bitmap memory.

Furthermore, since the lattice tilted at 45 degrees has strong connectivity in the diagonal direction, the wobble of the diagonal lines becomes less noticeable. Furthermore, since the distance between adjacent dots in the triangular lattice is the same, the lattice arrangement does not depend on the angle of the diagonal lines, so any angle can be output with uniform quality.

Therefore, even small-sized characters can be output with higher quality than before.

In addition, since the present invention can be implemented without changing the pitch in the main scanning direction, it has many effects, such as making simple changes to existing character output devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the character output device of the present invention, FIG. 2 is a schematic diagram of a general laser printer, and FIG.
The figure shows a timing clock, Figures 4 and 5 are diagrams explaining the first embodiment, Figures 6 and 7 are diagrams explaining the second embodiment, and Figures 8 and 9 are diagrams explaining the second embodiment. It is a figure explaining a 3rd example. 8... Output data storage section 9... Character pattern data storage section 10... Bit data creation section 11... Bitmap memory 12... Bitmap memory control section 13... Main scanning control section 14... Main scanning section 15... Sub-scanning control section 16... Sub-scanning section 17... Recording member

Claims (1)

[Claims] (1) In a character output method for outputting characters from a laser printer or the like, when the pitch of dots in the main scanning direction is P_H, the pitch P_V of dots in the sub-scanning direction is smaller than the pitch P_H. 1. A character output method characterized in that the timing of beam ON-OFF modulation is shifted for each scanning line and outputted. (2) In a character output method for outputting characters etc. from a laser printer etc., when the dot pitch in the main scanning direction is P_H, the dot pitch P_V in the sub-scanning direction is set smaller than the pitch P_H, and one scanning A character output method characterized in that the timing of beam ON-OFF modulation is shifted by 1/2 period for each line and output. (3) When the pitch of dots in the main scanning direction is P_H, the pitch of dots in the sub-scanning direction P_V is P_V=2
/P_H. A character output method according to claim (1) or (2). (4) When the dot pitch in the main scanning direction is P_H, the dot pitch P_V in the sub-scanning direction is P_V=P
_HSin60°. A character output method according to claim (1) or (2). (5) When the pitch of dots in the main scanning direction is P_H, the pitch of dots in the sub-scanning direction P_V is P_V=P
The character output method according to claim 1 or 2, characterized in that _H/2Tan60°. (6) In a character output device such as a laser printer, when the dot pitch in the main scanning direction is P_H and the dot pitch P_V in the sub-scanning direction is P_V=P_H/2, the angle of 45° with respect to the main scanning direction is Angle pitch P_HS
A character output device characterized in that it outputs bit data of a character pattern created so that dots are placed on an in45° grid. (7) In a character output device such as a laser printer, when the dot pitch in the main scanning direction is P_H and the dot pitch P_V in the sub-scanning direction is P_V=P_HSin60°, the distance P_L between adjacent grid points is A character output device that outputs bit data of a character pattern created such that P_L=P_H and dots are placed on a triangular lattice whose base is horizontal to the main scanning direction. (8) In a character output device such as a laser printer, when the dot pitch in the main scanning direction is P_H and the dot pitch P_V in the sub-scanning direction is P_V=P_H/2Tan60°, the distance between adjacent grid points P_L A character output device is characterized in that it outputs bit data of a character pattern created such that P_L=P_H/Tan60° and dots are placed on a triangular lattice whose base makes an angle of 30° with respect to the main scanning direction. .