JPH01133743A - Image output apparatus - Google Patents

Abstract

PURPOSE:To enhance the output speed of image data, by utilizing a memory for storing unused color data as the auxiliary buffer of indicated color data when the output by colors less than the number of colors possible in output is indicated. CONSTITUTION:At the time of monochromatic printing, a change-over signal 25 is set to a low level and an AND circuit 27 is closed while an AND circuit 28 is opened and the output of a parallel/series converter circuit 16 is outputted to an image forming part 12 from an OR circuit 26. A predetermined amount of the code data of a page memory 2 is subjected to pattern development to be stored, for example, in a dot pattern memory 6. Next, when a drum rotation indicating signal 29 is outputted to the image forming part 12, the feed of paper is started and, at the same time, a predetermined amount of the code data of the page memory 2 is stored in other dot pattern memory 7. When a reading indicating signal is outputted to a reading control part 8 and the reading of the memory 6 is finished, said reading is altered to the reading from the memory 7 from the next time and the writing to the memory 6 is performed. By this method, when printing by colors less than the number of printable colors is indicated, by utilizing the buffer of a not-indicated color, a printing buffer is effectively utilized to make it possible to increase a printing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image output device capable of displaying and outputting image information sent from a host computer or the like in multiple colors.

[Prior Art] An output device capable of outputting characters, etc. in two or more colors has a plurality of buffers corresponding to each color information. In this way, image data from an external device is usually stored in a buffer corresponding to the color, so if, for example, only monochromatic image information is input, no other buffers are used at all.

[Problem to be solved by the invention] This is shown in the timing chart in Figure 3.
The figure shows a case where a two-color buffer is provided and image data of only one color is input. At this time, only the path of one buffer is accessed, as shown at 300, and the bus of the other buffer is not accessed at all, as shown at 301. Here, W indicates the state of writing into the buffer, and R indicates the state of reading from the buffer.

FIG. 4 is a diagram showing a timing chart of the embodiment.
00 is a timing chart when image formation is performed by inputting two-color data, and this timing is the same in a conventional two-color printer. In this way, Figure 3 is
It can be seen that the amount of data processed is reduced compared to 400 in the figure. For this reason, for example, in a laser beam printer capable of printing in two colors, if one color cannot be printed due to toner exhaustion or the like, there is a problem in that the printing ability is reduced. Furthermore, since monochrome printing was sufficient, it was not possible to meet the demand for faster printing.

The present invention was made in view of the above-mentioned conventional example, and when the number of input color information is the same as the number of printable colors, as in the past, a buffer for storing pattern information is used to print the input color information. If the number of information is less than the number of colors that can be printed, the data output speed can be increased by using the buffer for the color that was not input as an auxiliary buffer for other color data, for example, creating a double buffer configuration. An object of the present invention is to provide an image output device that can increase the image quality.

[Means for Solving the Problems] In order to achieve the above object, the image output device of the present invention has the following configuration. That is, it is an image output device that inputs code information from an external device, develops it into pattern information, and displays and outputs the pattern information in a plurality of colors using an image forming section, the image output device including a plurality of memory cells that store the pattern information in correspondence with the plurality of colors. a storage means, a reading means provided corresponding to the storage means and reading out the pattern information from the storage means, and an output from the reading means being switched to an image forming section different from the color information of the code information. When the number of colors of the output means to output and the input code information is smaller than the number of the storage means, the storage means that does not store the corresponding color information is used as the storage means corresponding to the input code information, and control means for controlling the output means to output to the image forming section.

[Operation] In the above configuration, the plurality of storage means stores pattern information corresponding to a plurality of colors, and reading means for reading pattern information from the storage means is provided corresponding to the storage means.

When the number of colors of the inputted code information is smaller than the number of storage means, the control means uses the storage means that does not store the corresponding color information as the storage means corresponding to the inputted code information, and reads the information from the reading means. The output means which switches the output and outputs the output to an image forming section different from the color information of the code information operates to switch and output the output of the reading means.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of Two-Color Laser Beam Printer (FIGS. 1 to 4)] FIG. 1 is a block diagram showing a schematic configuration of a two-color laser beam printer according to an embodiment.

In the figure, 1 is an input control unit that inputs document information and image data from an external device such as a host computer. Image data, etc. input from the external device through the input control unit 1 is Each color is stored in page memories 2 and 3 having a capacity for at least one page. The data stored in the page memory 2 is, for example, a first color such as black.
The page memory 3 stores image information and document information of a second color such as red, for example.

Reference numeral 4 denotes a character pattern generation unit used to develop the code information into pattern data when the document information stored on the page memory 2 consists of code information. code information is input, and corresponding pattern data is output to the main control section 5.

5 is a main control unit that controls the entire printer, including a CPU such as a microprocessor, a ROM that stores control programs and data for the CPU, the flowchart of which is shown in FIG. 5, and a ROM that stores various data as a work area for the CPU. It is equipped with a RAM for temporarily storing data. Dot pattern memories 6 and 7 correspond to the page memories 2 and 3, respectively, and store pattern data for at least one page. In this way, for example, the code information of the page memory 2 is stored in the dot pattern memory 6, and the code information of the page memory 2 is stored in the dot pattern memory 7.
The code information in the page memory 3 is developed into a pattern using the character pattern generating section 4 and stored.

Reference numerals 8 and 9 denote read control units that control the readout of the dot pattern memories 6 and 7, respectively.
horizontal synchronization signal 1 from the image forming section 12.
3.14, the corresponding scan buffer 10.
The pattern data is output to 11.

Reference numeral 10.11 is a scan buffer that stores pattern data for one scanning line scanned by a laser beam out of one line of pattern data to be printed. , scan buffers 10 and 1
1 stores pattern data of different colors from the dot pattern memories 6 and 7, respectively. 15 and 16 are parallel to serial converters that input parallel data from the scan buffer 10 or 12, convert it into serial data, and output it.

12 is an image forming section whose details are shown in FIG.
．． Converted to bit serial from 16, gate circuit 2
Serial data 21, 22 output through 6.27
input and form images in different colors. The main control unit 5 sets the switching signal 25 to high level when printing in two colors, and sets it to low level when printing only in a single color (for example, black).

[Description of Image Forming Section (FIG. 2)] FIG. 2 is a diagram schematically showing an image forming section that forms images in two colors (for example, red and black) using two lasers.

In the figure, 40.41 is the serial image signal 21.2, respectively.
2 and drives the corresponding semiconductor lasers 42 and 43. 44 is a motor that rotationally drives the polyhedral rotating mirror 45, and 46 is an f-θ lens. 47 is a charger that charges the photosensitive drum 50; 48 is a developer that develops the electrostatic latent image of the first color; 49 is a developer that develops the electrostatic latent image of the second color; and 51 is the image on the recording paper 52. This is a fixing device that fixes images.

The laser beam from the semiconductor laser 4'2, 43 is reflected by the polyhedral rotating mirror 45, sweeps the photosensitive drum 50''2 in the horizontal direction, and is imaged on the photosensitive drum 50 by the f-θ lens 46.

As is clear from FIG. 2, since the angles of incidence of the two laser beams incident on the polyhedral rotating mirror 45 are different, the two laser beams are swept over the photosensitive drum 50.

Both beam detectors 53 and 54 are composed of photoelectric conversion elements with fast response times such as PIN diodes, and each detects the start of the sweep of the laser beam and outputs a horizontal synchronizing signal 13 and 14.

55 is an earth probe using a Hall element etc. that utilizes the Hall effect.
A magnet 57 of a disk 56 mounted on the rotating shaft of the photosensitive drum 50 is detected and a drum rotation synchronization signal 58 is output. Based on this rotation synchronization signal 58, the main control section 4 determines the timing to start rotating the photosensitive drum 50 and to start transporting the recording paper 52.

In this way, one of the laser beams irradiated onto the photosensitive drum 50 is visualized by the first color developer 48 according to a known electrophotographic process, and the other laser beam is developed in the same manner. After being visualized by the second color developing device 49, it is transferred onto the recording paper 52 by a transfer device (not shown), and further fixed by the fixing device 51, and output as a hard copy.

The operation of the laser beam printer of the embodiment will be described above based on FIGS. 1 and 2.

When the print data for at least one page to be imaged by the image forming section 12 is stored in the page memories 2 and 3, the main control section 5 reads the code information of the page memories 2 and 3,
The character pattern generator 4 converts the code information into pattern information. This converted pattern information is stored in the corresponding dot pattern memory 6.7.

The readout control section 8.9 inputs the readout instruction signals 17 and 18 from the main control section 5, and reads the corresponding dot pattern memory 6.
．． The pattern information is read from 7.

400 in FIG. 4 is a diagram showing the timing of this operation.
02 indicates the state of the data bus 23, and 4°3 indicates the state of the data bus 24. Here, W indicates the state of writing into the dot pattern memory by the main control section 5, and R indicates the timing of reading from the dot pattern memory by the read control section. Although the data buses 23 and 24 are independent from each other, when data is written from the main control section 5, one of the buses enters a wait state. Image information for at least one scan of the pattern information thus read out is stored in a corresponding scan buffer 10.11, and converted into serial data by a corresponding parallel-to-serial converter 10.11.

When printing is instructed, the photosensitive drum 50 starts rotating, and when the magnetism of the magnet 57 is detected by the detector 55, a rotation signal 58 is output and input to the main control section 5. As a result, the main controller 5 outputs read signals 17 and 18 to the read controllers 8 and 9, respectively, and the dot pattern memory 6
．． Instructs to start reading 7. The readout control units 8 and 9 each read out the corresponding dot pattern memory 6.7 in synchronization with the horizontal synchronization signal 13.14 and output it to the corresponding scan buffer 10.11.

Further, when the main control section 5 inputs the rotation signal 58, the main control section 5 sends a conveyance start signal 30 of the recording paper 52 to the image forming section 1 at a predetermined timing.
Output to 2. As a result, the leading edge of the image data irradiated onto the photosensitive drum 50 is adjusted so as to match the leading edge of the recording paper 52. The serial image signals 21, 22 and the scanning of the laser beam are synchronized by inputting the horizontal synchronizing signals 13, 14 from the beam detectors 53, 54 to the main controller 5 and the readout controller 8.9. taken. In addition, the image forming section 1
The conveying roller 59 in No. 2 is controlled to stop after conveying one sheet of recording paper 52.

Next, an example of printing in a single color, for example, in the printing of this embodiment, which is a feature of this embodiment, will be explained.

[Operation Description (FIG. 5)] FIG. 5 is a flowchart showing print processing in the printer of the embodiment.

In step S1, it is checked whether image data, document data, etc. are input from an external device through the input control section 1. When the data is input, the process advances to step S2, and the image data is stored in the page memory 2 or 3 in accordance with the color information. The printing start state is changed depending on whether printing is started by storing one page of image data or document data in the page memory 2 or 3 in step S3, or whether a print start instruction is input from an external device, etc. Let's see what happened.

When printing starts, the process advances to step S4, and the page memory 2 is
, 3, that is, whether printing in multiple (two colors) has been instructed.

When two-color printing is instructed, the process advances to step S5, where the character pattern generating section 4 is used to develop the pattern of the code information in the page memory 6.7, and the pattern data is transferred to the data bus 23.24 through the CPU bus 31. By outputting, writing to the dot pattern memories 6 and 7 is performed.

In step S6, the switching signal 25 is set to high level, and in step S7, a drum rotation instruction signal 29 is output to the image forming section 12. In step S8, it waits for the rotation signal 58 to be input, and when the rotation signal 58 is input, the process advances to step S9, and a paper conveyance instruction is output. This synchronizes the position of the paper to be printed and the image data.

In step SIO, the read control section 8.9 is instructed to read from the dot pattern memory 6.7, and one scan worth of image data is transferred from the dot pattern memory 6.7 to the scan buffer 5.6. This shows image data for one scan of laser light.

Dot pattern memory 6.7 by readout control units 8 and 9
The pattern data is read from the address indicated by the address bus 19.20 from the read control unit 8.9, respectively. Therefore, for example, while the read control section 8 is reading data from the dot pattern memory 6 in response to an instruction from the read signal 17, the main control section 5 reads data from the data bus 23 and the dot pattern memory 6 from the CPU bus 31. Prohibit address output.

Incidentally, when the image data in the page memories 2 and 3 is pattern data, it goes without saying that the pattern data is output as is to the dot pattern memories 6 and 7.

When the horizontal synchronizing signal 13 or 14 is input in step S11, it is checked in step S12 whether output for one page has been completed. If the output for one page has not been completed, the process returns to step s10 and the above-described operations are executed.

On the other hand, when printing is performed in a single color (black) in step S4, the process proceeds to step S13, and the switching signal 25 is set to a low level. As a result, the AND circuit 27 is closed and the AND circuit 28 is opened, so that the output of the parallel-to-serial converter 16 is output from the OR circuit 26 to the image forming section 12. Step S14
A predetermined amount of code information in the page memory 2 is developed into a pattern and stored in, for example, a dot pattern memory 6.

Next, in step S15, the drum rotation instruction signal 29 is output to the image forming section 12, and in step S16, the input of the rotation signal 58 is awaited. In this way, when the drum rotation signal 58 is input, the process advances to step S17, and the paper conveyance start signal 58 is inputted.
Instructs to start conveying the paper. At step 51B, at the same time, a predetermined amount of code information in the page memory 2 is expanded into a pattern and stored in the other dot pattern memory. Then, in step S19, a read instruction signal is output to the read control section (8) corresponding to the dot pattern memory (initially dot pattern memory 6) other than the dot pattern memory in which the pattern was stored in step 31B.

Step S20 waits for the horizontal synchronizing signal 13 to be input, and when the horizontal synchronizing signal is input, the process advances to step S21, where it is checked whether reading of the dot pattern memory (6) has been completed, and if not, step Returning to S20,
When the process is completed, the process advances to step S22, and the dot pattern memory to be read from the next time is exchanged with the dot pattern memory to be written. That is, if reading from the dot pattern memory 6 has been performed up to now, the reading from the dot pattern memory 7 will be changed from now on, and writing to the dot pattern memory 6 will be performed.

This is shown by 401 in FIG. 4, 404 shows the state of the data bus 23 of the dot pattern memory 6, and 405
indicates the state of the data bus 24 of the dot pattern memory 7. In this manner, only the dot pattern memory 6 is read out in the section 406, and only the dot pattern memory 7 is read out in the section 407, so that writing to the dot pattern memory can be performed continuously.

Such switching of access to the dot pattern memory 6.7 is performed by the read signal 17.18 and the bus 31. That is, for example, while data is being read from the dot pattern memory 6, the main control section 5 does not output addresses and data to the dot pattern memory 6 through the data bus 23 and the bus 31, Write data and a write address are output to the data bus 24 and address bus, respectively. During this time, the readout control section 9 remains stopped, and the readout control section 8 outputs the address of the dot pattern memo 26 to the address bus 19 to read out the pattern data.

It can be seen that by doing this, the usage efficiency of the CPU bus is significantly improved compared to the conventional example shown in FIG.

In step S23, it is checked whether printing has been completed, and if printing has not been completed, the process returns to step S19 and the aforementioned operations are performed.

Although this embodiment has been described using a two-color laser beam printer that prints out image data, the present invention is not limited to this, and may be a color display device such as a color display.

Further, although the present embodiment has been described for the case of two colors, the present invention is not limited to this, and of course can be applied to a case where there are even more colors.

As explained above, according to this embodiment, when printing is instructed with fewer colors than the number of printable colors, the print buffer is effectively used by using the buffer of the unspecified color. Printing speed can be increased.

[Effects of the Invention] As described above, according to the present invention, when an instruction is given to output colors smaller than the number of colors that can be output, the memory for storing unused color data is replaced with the instructed color data. By using it as an auxiliary buffer, it has the effect of increasing the output speed of image data.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the schematic configuration of the two-color laser beam printer of the embodiment, Fig. 2 is a diagram showing the outline of the image forming section that forms two-color images, and Fig. 3 is a diagram showing the pattern data of the conventional example. FIG. 4 is a diagram showing write and read timings. FIG. 4 is a diagram showing buffer write and read timings in the embodiment. FIG. 5 is a flowchart showing print processing in the printer of the embodiment. In the figure, 1... input control unit, 2, 3... page memory, 4... character pattern generation unit, 5... main control unit, 8
．． 9... Readout control section, 10.11... Scan buffer, 12... Image forming section, 13.14... Horizontal synchronization signal, 15, 16... Parallel-to-serial conversion section, 17.18.・
- Read signal, 19.20...address bus, 21.
22... Image signal, 23.24... Data bus, 2
5...Switching signal, 29...Drum rotation signal, 30.
...Paper transport start signal, 50...Photosensitive drum, 58...
・It is a rotation signal.

Claims (1)

[Scope of Claims] An image output device that inputs code information from an external device, develops it into pattern information, and displays and outputs the pattern information in a plurality of colors using an image forming section, wherein the pattern information is converted into pattern information corresponding to the plurality of colors. A plurality of storage means for storing, a reading means provided corresponding to the storage means and reading out the pattern information from the storage means, and an output from the reading means that is switched so that the color information is different from the color information of the code information. an output means for outputting to the image forming section; and when the number of colors of the input code information is less than the number of the storage means, a storage means that stores no corresponding color information and a storage means corresponding to the input code information; an image output apparatus, comprising: a control means for controlling the output means to output the image to the image forming section;