JPH07156448A - Printer - Google Patents

Abstract

PURPOSE:To remove deterioration in quality of a character owing to quantization by providing a means or the like wherein a data read out from a storage means is processed by smoothing, and restored to a bit map data conforming to output resolution. CONSTITUTION:A character device 111 generates a character data using an outline font in conformity with output resolution based on information sent from an external device 120, and transfers it to a thinning out processor 112 as a bit map data. The thining out processor 112 stores the character data processed by thinning out in a memory 113 by using a specific thinning out processing method. The bit map data is a bit map data of the character data generated by using the outline font in the character generation device 111. By thinning out all bits of the bit map data longitudinally and laterally respectively by each one dot interval, the bit map data is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device for outputting characters, images and the like.

[0002]

2. Description of the Related Art As in the printer disclosed in Japanese Patent Laid-Open No. 4-301469, character data having a resolution lower than the output resolution is generated in the printer or received from an external device, and the character data is directly smoothed. There is a printing device that obtains a desired high-resolution output by performing a development process involving.

[0003]

However, in the above apparatus, when the character data is generated by using the outline font, if the character data becomes small, for example, the resolution is 600 dpi and the character size is 4 points shown in FIG. 9A. As in the bit map data 901, the character quality is deteriorated due to the influence of the quantization error generated in the calculation process at the time of character generation.

Therefore, even if the deteriorated bitmap data 901 is subjected to the expansion process accompanied by the smoothing process,
In the resulting character data, the deterioration of the character quality due to the quantization error is reproduced as it is, as in the bitmap data 902 shown in FIG. 9B.

Therefore, in order to reduce the quantization error,
If the bitmap data is generated with the same resolution as the output resolution, the quantization error will be suppressed and the character quality will be improved, but the memory capacity for storing the bitmap data will increase, and the required memory capacity will be output. It increases in proportion to the square of the resolution.

The present invention has been made in view of the above problems, and an object thereof is to increase the memory capacity for storing the character data when the character data is generated using an outline font. It is an object of the present invention to provide a printing device that does not cause deterioration of character quality due to quantization even in small character data.

[0007]

A printer according to the present invention reads contour information from an outline font in which contour information of a character is stored in association with a character code,
In a printing device for converting characters into bitmap data and printing characters, thinning processing means for performing thinning processing on the bitmap data and reducing the bit amount of the bitmap data, and storing output results of the thinning processing means A thinning bit data storage means, and a expanding means for reading data from the thinning bit data storage means at the time of printing, performing smoothing processing on the data, and restoring the bitmap data to match the output resolution. Characteristic printing device.

Further, the thinning-out processing means deletes the vertical and horizontal rows of the bitmap data at predetermined intervals.

Furthermore, the thinning-out processing means is for converting an n × m (n, m is a natural number) matrix of the bitmap data into one pixel.

[0010]

In order to suppress the quantization error, the bitmap data is generated with a high resolution that matches the print output resolution, and then the bitmap data is compressed by the thinning processing means. It does not include a conversion error and requires a small storage capacity.

Since the bit map data compressed at the time of printing is read and smoothing is performed according to the output resolution, high quality printing without quantization error can be performed.

[0012]

EXAMPLES The present invention will be described in detail below based on examples.

FIG. 1 is a block diagram showing components of a printing apparatus 101 according to the present invention. A printing apparatus 101 according to the present invention includes a character generation device 111 that generates character data using an outline font based on control information sent from an external device 120, and a thinning process that performs a thinning process of character data obtained from the character generation device 111. Processor 1
12, a memory 113 for storing the character data thinned by the thinning processing device 112, and a decompressing device 114 for decompressing the data stored in the memory 113 to a desired output resolution while performing a smoothing process. The output device 115 outputs the character data expanded by the expansion device.

The output device 115, as shown in FIG.
A multi-scan print head 202 and a transfer pressing roller 20 that is a transfer unit are provided around a transfer drum 201 that is a transfer medium.
3 are arranged to output desired printing on the recording paper 204 which is a recording medium.

The transfer drum 201 is rotatably supported by the multi-scan print head 202 with a certain gap therebetween in the direction of the arrow in the figure. The driving is performed by a drum driving motor 211, and is controlled by an output signal of a rotary encoder 212 mounted on the transfer drum 201.
The output signal of the rotary encoder 212 is further the basis of ink ejection timing and movement timing of the multi-scan print head 202.

The multi-scan print head 202 is a multi-scan print head of a type using a piezoelectric element, and ink is supplied from an ink container 228 through an ink supply pipe 229. Further, the multi-scan print head 202 has a plurality of nozzles at regular intervals in the axial direction of the transfer drum 201, and the plurality of nozzles 301 shown in FIG. 302,
, 303, ... Are selectively ejected. The multi-scan print head 202 configured as described above is used for the transfer drum 2 during recording.
In synchronization with the rotation of 01, an ink image is formed on the transfer drum 201 by moving the transfer drum 201 in the axial direction every one rotation by a head moving device (not shown). For example, in this embodiment, as shown in FIG. 3, the multi-scan print head 202 has 512 pitches of 8/300 inches.
It has a number of nozzles, and moves 1/600 inch every time the transfer drum 201 makes one rotation, thereby completing the ink image formation in 16 rotations. Multi-scan print head 202
Is fixed on the head holding member 225, and the movement guide 22
6, the drive motor 224 moves in synchronism with the rotation of the transfer drum 201.

After the ink image formation on the transfer drum 201 is completed, the recording paper 204 is conveyed by the conveying roller 241 to the transfer pressing roller 203. Transfer drum 2 in this state
01 and the transfer pressing roller 203 are brought into contact with each other, pressure is applied by the transfer pressure applying means 233, the recording paper 204 is passed through this contact portion, and the applied pressure causes the ink image on the transfer drum 201 to be transferred onto the recording paper 204. Transfer to and print. When the transfer of the ink image to the recording paper 204 is completed, the recording paper 204 is ejected and the contact between the transfer drum 201 and the transfer pressing roller 203 is released.

Next, a process of outputting character data to the output device will be described.

The character device 111 generates character data using an outline font in accordance with the output resolution based on the information sent from the external device 120, and transfers it to the thinning processing device 112 as bitmap data.

The thinning processing device 112 stores in the memory 113 the character data subjected to the thinning processing using the thinning processing method described below.

FIG. 4 is a diagram showing one embodiment of the thinning-out processing method (hereinafter referred to as thinning-out processing method 1). Bit map data 401 is a character generated by the character generation device 111 using an outline font. It is bitmap data of data. Bit map data 40
Bit-map data 402 is obtained by thinning out all dots of one dot at intervals of 1 dot vertically and horizontally. Bit-map data 403 subjected to thinning processing is obtained by closing the thinned gaps of the bitmap data 402. To be

FIG. 5 is a diagram showing another embodiment of the thinning-out processing method (hereinafter referred to as thinning-out processing method 2), which is 2.times.2 for all dots of the bitmap data 401.
Bit map data 501 is obtained by referring to the dot matrix (thick line in the figure). When looking at the state of each dot surrounded by the matrix of 2 × 2 dots, when there are two or more black dots, the matrix of 2 × 2 dots is set to black, and the number of black dots is 1 dot or less. Bitmap data 502 can be obtained by sometimes performing a process of making a matrix of 2 × 2 dots white. By closing the gap of the bitmap data 502, the bitmap data 503 subjected to the thinning process can be obtained.

By performing the thinning-out processing using the above-described thinning-out processing method, the dot density is compressed to 1/2 in each of the vertical and horizontal directions, and the data amount of the character data becomes 1/4. Therefore, the capacity of the memory for storing the character data may be 1/4 of the capacity for storing the character data in the output resolution.

The thinning processing method shown in FIG.
Although the matrix of 2 is referred to, the same effect can be obtained by referring to the matrix of n × m (n and m are natural numbers).

Since a transfer type output device is used in this embodiment, the bit map data shown in FIG. 4 and FIG.

Next, a method of expanding the character data thinned by the thinning processing method to a desired output resolution (600 dpi in this embodiment) while performing a smoothing processing (hereinafter referred to as a developing method) will be described. To do.

The dot density of the character data obtained by thinning the 600 dpi character data generated using the outline font in the character generation device 111 using the thinning processing method 2 is compressed to 1/2 in each of the vertical and horizontal directions. Has been done. Therefore, the character data is converted into the original 60
To convert the resolution to 0 dpi, the dot density may be doubled vertically and horizontally. That is, one dot of the character data is a dot pattern composed of 2 × 2 dots (hereinafter,
It is possible to perform the expansion process by replacing it with a correction pattern). In addition, the smoothing effect can be obtained at the same time by selecting and replacing an appropriate correction pattern. The correction pattern is not limited to 2 × 2 dots because it depends on the thinning processing method.

FIG. 11 is a diagram showing a method of selecting the correction pattern.

FIG. 11A shows the 3 × 3 used in this embodiment.
Of the matrix (hereinafter referred to as a reference matrix), bitmap data is placed on the reference matrix so that a dot to be replaced by a correction pattern (hereinafter referred to as a target dot) is in the center, and the target dot is d0.
It is divided into four, 0, d01, d10, and d11.

FIG. 11B is a diagram showing dots (dots indicated by arrows in the drawing, hereinafter referred to as adjacent dots) adjacent to the divided dots (hereinafter referred to as divided dots). The dot is judged to be black and white by referring to the adjacent dot. That is, if any one of the adjacent dots is black, the divided dot is black, and if all of the adjacent dots are white, the divided dot is white. However, when the target dot is white, the divided dots are all white without reference to adjacent dots.

For example, as shown in FIG. 11C, D00
= Black, D01 = Black, D02 = Black, D10 = Black, D11
(Dot of interest) = 1, D12 = black, D20 = black, D21
= White, D22 = white, d00, d01, d
The reference results of 10 and d11 are black, white, black, and black, respectively.

Here, if the black of the reference result of the divided dots is treated as 1 white and 0, it can be expressed as a binary number. For example, d
When 00, d01, d10, and d11 are arranged in this order, the reference result becomes 1011 (binary number), and when converted into decimal number, the number becomes 11 (decimal number). The range of the number is from 0 to 15, and the correction pattern can be selected by using the number as a number for selecting one correction pattern from several correction patterns.

When black is treated as 1 and white is treated as 0,
The reference result of the divided dots can be expressed by the following logical expression (+ symbol indicates logical OR, * symbol indicates logical AND).

D00 = (D00 + D01 + D10) * D11 d01 = (D01 + D02 + D12) * D11 d10 = (D10 + D20 + D21) * D11 d11 = (D12 + D21 + D22) * D11 The above logical expression can be configured by the logical circuit shown in FIG.

The development method used in this embodiment is as described above.

FIG. 7 shows an example of a simple expansion process using the expansion method.

FIG. 7A shows the bit map data 701 of diagonal lines. When the bit map data 701 is thinned out, the bit map data 702 shown in FIG. 7B.
Then, when the expansion processing is performed on this, the bitmap data 703 shown in FIG. 7C is obtained.

FIG. 6 is a block diagram of the expanding device 114 using the above-described expanding method. The pattern referring device 60 is shown in FIG.
1, pattern selection device 602, correction pattern storage device 6
03, an input buffer 604, and an output buffer 605. The correction pattern storage device 603 stores 16 types of correction patterns 0 to 15 shown in FIG. 8 which are prepared in advance.

The pattern reference device 601 reads the bitmap data from the input buffer 604 and then stores it in the reference matrix. Then, the pattern reference device 60
First, the number of the correction pattern to be replaced with the dot of interest is calculated using the above-described expansion method, and then the number of the correction pattern is sent to the pattern selection device 602.

The pattern selection device 602 selects a correction pattern from the correction pattern storage device 603 according to the number of the correction pattern sent from the pattern reference device 601, replaces it with the dot of interest, and stores it in the output buffer 605 as 600 dpi bitmap data. To do.

The bitmap data stored in the output buffer 605 is transferred to the output device 115 and output as needed.

By performing the above operation for all dots of the character data, the smoothed 600d is obtained.
The character data of pi is printed.

FIG. 10 shows the bit map data of the character data in each process as an example of printing when the character data is printed according to the operation described above.

FIG. 10A is a diagram showing bitmap data 1001 of 8-point (600 dpi resolution) character data generated using an outline font in the character generation device 111.

FIG. 10B shows the bit map data 1002 of the character data in which the character data is thinned by the thinning processing device 112 using the thinning processing method 2 to 4 points (resolution 600 dpi). In the figure, character data having a resolution equivalent to that of the character data shown in the bitmap data 901, but having a character quality higher than that of the bitmap data 901 can be obtained.

FIG. 10 (c) is a diagram showing bitmap data 1003 of character data obtained by subjecting the thinned character data to the expansion processing accompanied by smoothing processing in the expansion device 114. Although the resolution is the same as that of the 8-point character data that is the same as the bitmap data 902, character data having higher character quality than the character data shown in the bitmap data 902 can be obtained.

Although the print head has been described as a multi-scan print head in this embodiment, the print head is not limited to this.

Further, although the output device is described as the transfer type output device in the present embodiment, the output device is not limited to this and may be a device which directly prints on the recording medium.

In this embodiment, the high resolution conversion processing to 600 dpi has been described as an example, but the resolution is not limited to this.

[0050]

As described above, after the outline information is read from the outline font in which the outline information of the character is stored in association with the character code and the bitmap data is generated with the resolution that suppresses the quantization error. Since compression is performed by thinning out the bitmap data, it is possible to reduce the storage memory capacity without including the quantization error. Then, at the time of printing, the compressed bitmap data is subjected to smoothing processing to be restored to bitmap data that matches the output resolution, so that it is possible to obtain a high-quality print output that does not include a quantization error.

[Brief description of drawings]

FIG. 1 is a block diagram showing components of a printing apparatus of the present invention.

FIG. 2 is a schematic diagram of an output device having a multi-scan print head used in this embodiment.

FIG. 3 is a schematic diagram of a multi-scan print head used in this embodiment.

FIG. 4 is a diagram showing a thinning-out processing method 1 used in this embodiment.

FIG. 5 is a diagram showing a thinning-out processing method 2 used in this embodiment.

FIG. 6 is a block diagram showing components of a smoothing processing device used in this embodiment.

FIG. 7A is a diagram showing bitmap data of diagonal lines used in this embodiment, and FIG. 7B is a bitmap data 7
01 is a diagram showing the result of performing the thinning-out process on 01, and (c) is a diagram showing the result of performing the expanding process on the bitmap data 702.

FIG. 8 is a diagram showing a correction data group used in this embodiment.

9A is a diagram showing bitmap data of 4-point character data generated using an outline font in this embodiment, and FIG. 9B is a diagram showing the bitmap data of 4 points in this embodiment.
It is a figure which shows the bitmap data of the character data produced | generated by carrying out the expansion process with smoothing of the character data of a point.

10A is a diagram showing bitmap data of 8-point character data generated using an outline font in the present embodiment, and FIG. 10B is thinned out to 8-point character data in the present embodiment. It is a figure which shows the bitmap data of the character data obtained by performing a process.
Is generated by performing expansion processing with smoothing on the character data obtained by performing the thinning processing in the present embodiment.
It is a figure which shows the bitmap data of the character data of a point.

11A is a diagram showing a reference matrix used in the present embodiment, FIG. 11B is a diagram showing reference pixels of divided dots in the present embodiment, and FIG. 11C is a diagram in the present embodiment. It is a figure which shows the reference result of a division dot.

FIG. 12 is a diagram showing a logic circuit of a correction pattern selecting method in the present embodiment.

[Explanation of symbols]

111 character generation device 112 thinning processing device 113 memory 114 expansion device 115 output device 401 character data of 600 dpi 403 result of thinning processing using the thinning processing 1 on the character data 401 503 thinning processing using the thinning processing 2 on the character data 401 Result of processing 601 Pattern reference device 602 Pattern selection device 603 Correction pattern storage device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04N 1/387 101 8420-5L G06F 15/66 355 P 9191-5L 15/68 410

Claims (3)

[Claims] 1. A printing apparatus for reading out the outline information from an outline font in which outline information of the character is stored in association with a character code, converting the outline information into bitmap data and printing the characters, thinning out the bitmap data. Thinning processing means for reducing the data amount of the bitmap data, thinning bit data storage means for storing the output result of the thinning processing means, and reading the data from the thinning bit data storage means at the time of printing. And a developing means for performing smoothing processing to restore bit map data suitable for output resolution. 2. The printer according to claim 1, wherein the thinning-out processing unit deletes columns and rows of the bitmap data at predetermined intervals. 3. The printer according to claim 1, wherein the thinning-out processing unit converts an n × m (n and m are natural numbers) matrix of the bitmap data into one pixel.