JPH0535260A - Image output device - Google Patents

Abstract

PURPOSE:To improve resolution as to characters and securely maintain original picture quality as to an image after gradation processing. CONSTITUTION:When there are image data in input data of one read page (S12: Yes), an image flag FG is set and when not, the image flag GF is reset. After the input data of the one page are developed into bit image data (S15), the bit image data are outputted to a DC controller (S17) when the image flag GF is reset (S16: Yes) or improved in resolution (S20) then outputted to the DC controller circuit when the image flag GF is reset (S16: No).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image output device provided with a resolution improving processing means for improving print quality or display quality, and particularly distinguishes character data and image data from input data input from the outside. However, the present invention relates to a device in which resolution improvement processing is performed on character data, but resolution improvement processing is not performed on image data.

[0002]

2. Description of the Related Art In recent years, laser printers for printing characters and images on printing paper by using, for example, a laser beam as image output devices have been rapidly miniaturized due to miniaturization and cost reduction due to the progress of semiconductor technology. .. On the other hand, in order that characters such as characters and symbols can be printed by this laser printer, the characters are stored as bit image data or contour line data (outline data), and each dot data (“1 The laser diode, which is a light emitting element of a semiconductor laser, is driven based on "or data of" 0 ") to print various characters on the printing paper.

By the way, in order to print the outline of the character more sharply, it is possible to increase the number of dots forming the bit image data of the character and to improve the resolution of the laser printer to correspond to the number of dots. However, there is a problem that the cost of the laser printer becomes high due to the increase in bit image storage memory due to the increase in bit image data and the complicated printing mechanism.

Therefore, based on the bit image data, the array of dot data represented by "1" or "0" is referred to, the contour is smoothed, and the resolution of the printed character is improved. Technology is proposed.

For example, Japanese Laid-Open Patent Publication No. 2-112966 discloses dot data (bit pattern) sampled through a sample window of a predetermined shape among bit image data developed on a bit image memory. When matching with a plurality of types of pre-stored pattern matching templates, dot data cut correction or filling correction is performed based on the template dot data, and the modulation frequency of these corrected dot data is changed. Describes an image output device in which the dot density of the laser beam in the main scanning direction is changed to significantly improve the resolution.

[0006]

The laser printer receives various input data such as character data of characters and graphic data from the outside. This graphic data has area gradation processing (gradation processing) using a dot arrangement of white and black in a predetermined area, such as photographic data consisting of black and white dots.
Image data may be included.

In the image output device described in Japanese Patent Laid-Open No. 2-112966, after input data received from the outside and mixed with character data and graphic data is expanded into bit image data on a bit image memory, Since the resolution improving process is performed on all the bit image data stored in the memory, the resolution of the character data is improved and the outline of the character is sharpened. However, for image data that has undergone gradation processing, such as the above-mentioned photographic data, cutting correction or filling correction of dot data is unnecessarily applied, resulting in an unnatural printing result in which the gradation that should be originally expressed has collapsed. Therefore, there is a problem that the image quality deteriorates.

It is an object of the present invention to provide an image output device capable of improving the resolution of a character and reliably maintaining the original image quality of a gradation-processed image.

[0009]

In order to achieve the above object, the image output apparatus of the present invention is, as shown in the functional block diagram of FIG. 1, interface means for receiving input data from the outside and this interface means. Data conversion means for converting input data received from the data conversion means into bit image data, storage means for storing the bit image data received from the data conversion means on a page-by-page basis, and resolution improving processing for the bit image data received from the storage means. In an image output apparatus having a resolution improving processing means to be applied and an output means for receiving serial bit image data from the resolution improving processing means and outputting the same to an output medium, input data is received from the interface means and input for each page. The data contains specific data that is not subject to resolution enhancement processing. And dolphin whether discrimination discriminating means,
When it is determined by the determination means that the specific data is included, the 1 is stored in the storage means without passing through the resolution improvement processing means.
Data transfer means for supplying serial bit image data for pages to the output means.

[0010]

In the image output apparatus of the present invention having the above structure, the data converting means converts the input data received from the interface means into bit image data, and the storing means converts the bit image data received from the data converting means into 1 Store pages.

On the other hand, the discriminating means receives the input data from the interface means and discriminates whether or not the input data for one page includes the specific data which is not the object of the resolution improving process. The resolution improvement processing means performs resolution improvement processing on the bit image data received from the storage means, and the output means receives the serial bit image data from the resolution improvement processing means and outputs it to the output medium.

At this time, the data transfer means, when the determination means determines that the specific data is included, outputs one page of serial bit image data from the storage means to the output means without passing through the resolution improvement processing means. Since it is directly supplied, the specific data is output without being subjected to the resolution improving process.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment is an embodiment in which the present invention is applied to a laser printer for printing input data transmitted from an external device such as a personal computer or a workstation.

The laser printer LP will be described with reference to FIG. 2. Since the laser printer LP has the same structure as a general laser printer, the laser scanner mechanism which is the main part thereof will be briefly described with reference to FIG. I shall explain.

The laser light LB emitted from the laser diode 32 by the laser drive signal generated by the DC controller 12 described later is corrected to parallel light by the collimator lens 1, further passed through the cylindrical lens 2, and then fixed by the scanner motor 33. It is converged on the polygon mirror 3 which rotates at a high speed. The laser beam LB whose angle is changed for each mirror surface of the polygon mirror 3 is the f-lens 4
The electrostatic latent image is formed by being main-scanned on the photosensitive drum 6 which is corrected by the above, is reflected by the reflection mirror 5, and is rotated at a predetermined speed.

Here, the laser beam LB at the start of each scan shown by the broken line is reflected by the beam detection mirror 7 and output to the DC controller 12 via the optical fiber 8 to start the output of the laser drive signal. Is converted to a horizontal sync signal.

Next, the control system of the laser printer LP will be described based on the block diagram of FIG. 3, but since this control system is the same as that of a general laser printer, it will be briefly described.

The control unit 10 of this laser printer LP comprises a video controller 11 and a DC controller 12. The video controller 1
Reference numeral 1 denotes a CPU 13, a ROM 14 in which a print control program, output data creation control, which will be described later, and various control programs are stored, and contour line data (outline data) defining contour lines of a large number of characters and symbols.
And a RAM 16 provided with a reception data buffer for receiving a predetermined amount of input data transmitted from the outside and a bit data expansion memory for storing one page of bit image data, and the like. , A dual port RAM (or FIFO memory) 17 for converting parallel data to serial data,
A timing control circuit 18 that generates a timing signal when writing / reading data to / from the RAM 16 and a serial interface (I / I) that receives input data such as character data and image data transmitted from the external device 100.
F) 19 and a video interface (V I / F) 20 having two scan buffers and sequentially outputting the print information converted into dot data to the DC controller 12.
And a resolution improving processing circuit 21 for performing resolution improving processing on bit image data of a character in order to make outlines of characters such as characters and symbols clear, and a scanning panel 2.
4 and cassette detector 2 for detecting the type of paper cassette
Panel interface (P.
I / F) 22 and these are respectively connected via a bus 23 such as a data bus.

The resolution improvement processing circuit 21 is provided with a buffer memory for storing bit data of a plurality of lines in the bit image data stored in the first development memory.

The resolution improving processing circuit 21 is similar to the processing circuit described in, for example, Japanese Patent Application Laid-Open No. 2-112966, and is composed of a hard logic circuit including a RAM chip and a data latch circuit. is there.

Therefore, among the bit image data for a plurality of lines, bit data corresponding to a window of a predetermined shape is sequentially collated with a plurality of types of pattern matching templates, and some of the bit data included in this window are compared. The size and the number of divisions of the correction target bit data are corrected.

As a result, the modulation frequency of the modified bit data is changed, and the resolution of the bit image relating to the character can be improved. The plurality of templates are stored in the ROM 14 in advance.

The DC controller circuit 12 of the control unit 10 is supplied with a main motor drive circuit 26 for the main motor 30, a heater drive circuit 27 for the fixing heater 31, an electric component circuit 28, and a high voltage. The control unit 10 is a high voltage unit 29 for
DC controller circuit 1 connected inside
A laser diode 32, which is a light emitting element of a semiconductor laser, and a scanner motor 33, which drives the polygon mirror 3 to rotate, are connected to 2.

Next, the output data creation control routine executed by the video controller 11 of the laser printer LP will be described with reference to the flowchart of FIG. However, it is assumed that input data transmitted from the external device 100 is sequentially stored in the reception data buffer of the RAM 16 by a data reception control program (not shown).

Further, the received input data is designated with character data for character data and a header including instruction information for designating the range of the character data is added, and for image data, image data is designated. In addition, a header including instruction information for instructing the range of the image data is added. In the figure, reference numeral Si
(I = 10, 11, 12 ...) is each step.

That is, when the input data is stored in the reception data buffer, this control is started, and the input data for one page is read from the reception data buffer (S1).
0), it is searched whether or not the header of the image data exists in this input data (S11). As a result, when the header of the image data is detected (S12; Ye
s), the image flag GF is set (flag data is "1") (S13), and when this header is not detected (S12; No), the flag GF is reset (flag data is "0"). (S14).

Next, this 1 is stored in the bit data expansion memory.
The input data for pages is expanded into bit image data and stored (S15). Next, when the flag GF is set (S16; Yes), the bit image data stored in the bit data expansion memory is not subjected to resolution improvement processing and is sequentially output to the DC controller circuit 12 as final bit image output data. Is done (S1
7).

Next, when the input data is present in the reception buffer (S18; No), S10 to S18 are repeated, and the bit image output data created for the input data for each page is sequentially output processed, and all the bit image output data are processed. When the output process is completed for the input data (S18; Ye
s), this control is ended and it returns to a main routine.

On the other hand, when the flag GF is reset, that is, when all the input data are character data (S
16; No), among the bit image data stored in the bit data expansion memory, the bit image data for a plurality of lines is transferred to the buffer memory of the resolution improvement processing circuit 21 via the dual port RAM 17 (S).
19) As described above, the resolution improving processing circuit 21 repeatedly executes the resolution improving processing on the bit image data for a plurality of lines for each window of a predetermined shape, and the processed bit image data is stored in the buffer memory. It is stored (S20). Next, the bit image data in the buffer memory is sequentially output to the DC controller circuit 12 as final bit image output data (S21).

Next, when the output of the bit image output data for one page is not completed (S22; No), S
39 to S42 are repeated, and when the output process for one page is completed (S22; Yes), and when the input data exists in the reception buffer (S18; No), S10 and subsequent steps are repeated as described above.

As described above, when the input data in page units includes image data that is not the target of the resolution improving process, the resolution improving process is not performed on the input data in page units, so that the gradation process is performed. Since the image can be printed without changing the gradation that should be originally expressed, the image quality can be reliably maintained. Further, with respect to characters that do not include an image, the resolution can be improved by printing by the resolution improving process for each page.

Needless to say, the present invention can be applied to various image printing apparatuses such as thermal transfer printers and ink jet printers having various resolution improving processing circuits.
It is needless to say that the present invention can be applied to various image display devices that include a display device such as a liquid crystal display or a CRT display and various resolution improvement processing circuits and display characters and images based on dot data. Is.

[0034]

According to the image output apparatus of the present invention, it is provided with the discriminating means and the data transferring means, and when the input data for each page unit includes the specific data which is not the object of the resolution improving process, Since the resolution improvement processing is not performed on the input data for the one page, the specific data included in the input data for the one page can be output without any change, while the input data for the one page that does not include the specific data can be output. Since the resolution improving process is performed on the input data, the resolution of the input data can be improved and output. For example, when the specific data is image data that has been subjected to gradation processing such as photographic data, and the input data other than the specific data is character data, the gradation that should be originally expressed is not changed for the gradation processed image. Since it is output without being processed, the image quality can be reliably maintained. Furthermore, for characters that do not include an image, the resolution can be improved page by page by the resolution improving process and output.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a schematic perspective view of a laser scanner mechanism of a laser printer.

FIG. 3 is a block diagram of a control system of the laser printer.

FIG. 4 is a schematic flowchart of a routine of output data creation control according to the embodiment.

[Explanation of symbols]

 LP laser printer 10 control unit 11 video controller 12 DC controller circuit 13 CPU 14 ROM 16 RAM 19 interface 21 resolution improvement processing circuit 100 external device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B41J 5/30 Z 8907-2C G06F 3/12 L 8323-5B 15/64 450 E 8840-5L 15 / 66 355 L 8420-5L H04N 1/23 Z 9186-5C 103 B 9186-5C Z 9186-5C 1/387 101 8839-5C

Claims (1)

Claim: What is claimed is: 1. An interface means for receiving input data from the outside, a data conversion means for converting the input data received from the interface means into bit image data, and a bit image received from the data conversion means. Storage means for storing data for each page,
An image output apparatus comprising: a resolution improvement processing means for performing resolution improvement processing on bit image data received from the storage means; and an output means for receiving serial bit image data from the resolution improvement processing means and outputting it to an output medium, Determining means for receiving the input data from the interface means and determining whether or not the input data for each page includes specific data which is not a target of the resolution improving process; and the determining means includes the specific data. When the determination is made, the image output device is provided with a data transfer unit that supplies serial bit image data for one page from the storage unit to the output unit without passing through the resolution improvement processing unit.