JPH106553A - Printer and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the toner-saving mode for a desired array in one image. SOLUTION: A data in which a printing data of ordinary mode is represented by 2 bits and a printing data of toner-saving mode is represented by 4 bits are read out of a plotting memory by a video control circuit 103 of a printer. Data representing the modes are added to the above data at the time of storing in the plotting memory. A 2-bit data is segmented from the bus width W of a system bus in the ordinary mode and a 4-bit data is segmented therefrom in the toner-saving mode as one dot by a bit segmenting circuit. The segmented data are decorded by a toner conversion table selector 303, and one is selected out of four tables in the ordinary mode, and one is selected out of twelve tables in the toner-saving mode, and the selected data is converted to a 8-bit data included in respective tables. The data are print output from an engine. The toner-saving mode can be set in a desired area by the above arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus having a function of saving the consumption of a recording agent such as toner, and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, some printing apparatuses using a toner as a recording agent have a function of a toner saving mode for saving the consumption of toner. When the toner saving mode is set in such a printing apparatus, the entire paper is targeted, and the toner consumption is reduced by reducing the image density over the entire paper.

[0003]

However, in a general document, sentences and pictures (graphics, graphs,
Tables, natural images, etc.) are often mixed. Particularly in business use color documents, graphs and tables can be separated by sentences even if the color coding is sufficient. Must be legible. Therefore, when the conventional toner saving mode is used, there is a problem that it becomes difficult to read a sentence even if there is no problem with a graph or a table. Also, not only sentences,
Decreasing the density of a fine image deteriorates the visibility of the image.

The present invention has been made in view of the above-described conventional example. Parts such as text parts which are difficult to see due to toner saving are not subjected to toner saving, and image density such as graphs, tables, natural images, etc. It is an object of the present invention to provide a printing apparatus that saves toner by providing a partial toner saving function that is a target of toner saving for a portion where there is no problem even if the image is dropped, and a control method thereof.

[0005]

In order to achieve the above object, the present invention has the following arrangement. That is, a designating unit for designating a desired toner-saving area from the print data, a determination as to whether or not the target dot of the print data is included in the specified area, and a determination that indicates the toner-saving mode for the target dot based on the determination result An adding unit for adding toner mode data, and, when the designated area does not include a dot of interest, converting the density data into density data according to the print data;
If included, a conversion unit is provided that converts the added toner-saving mode data as an index into density data corresponding to the print data, and a printing unit that prints out according to the density data converted by the conversion unit. .

[0006] A designation step of designating a desired toner-saving area from the print data, and determining whether or not the target dot of the print data is included in the specified area, and setting the target dot to the toner-saving mode based on the determination result. And an additional step of adding toner saving mode data indicating that the designated area does not include the dot of interest. If the target area does not include the dot of interest, the data is converted into density data corresponding to the print data. The method includes a conversion step of converting the toner mode data into density data corresponding to the print data by using the index as an index, and a printing step of printing and outputting according to the density data converted by the conversion step.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] First, an overview will be given. The printing apparatus of the present embodiment receives data from a host computer and stores data having a smaller number of bits than the original number of bits per pixel. Is converted into 8 bits using a gradation conversion table at the stage of outputting as a video signal, and transferred to a printing unit. In normal mode,
The internal processing is performed with 2 bits, and the data is converted into 8-bit data using four tables that can be represented by two bits, that is, four tables. In the toner save mode, two more bits are added to the upper part of the 2-bit internal processing data to make a total of four bits, and the four bits make 12 (1).
6 is used in the normal mode), and is converted into 8-bit data using the table. For this reason, it is necessary to store 4-bit data per pixel as toner-saving mode data, but 2-bits per pixel is sufficient for normal mode data. Hereinafter, a printing system according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration example of a printing system showing a schematic configuration of the present invention. In the printer 1, 100 is C
It is a PU (Central Processing Unit). Reference numeral 101 denotes a work memory (RAM and ROM) for storing a control program and various data and a work area. Reference numeral 102 denotes a drawing memory for storing print data, which is transferred to a printing unit (engine unit) 104 by a video circuit 103. Reference numeral 105 denotes other blocks. Further, it is connected to the host computer 2 by an I / O interface 106. The printer 1 is a host computer 2
And print data and image data are received from the printer driver.

In particular, the printer 1 is characterized in that the video circuit 103 has a gradation conversion table. In the printer 1, the internal processing is performed by 2 bits, and the video circuit 1
When the print data is transferred from 03 to the engine unit 104, the print data is converted to 8 bits using the gradation conversion table and transferred.

FIG. 2 shows an example of a general document in which a character, a graph, a natural image, and the like are mixed. In the present embodiment, instead of outputting the entire document as shown in FIG. 2 with toner saving, the graph and the natural image are partially made toner-saving, and the text portion is printed and output as usual without toner saving.

In order to print a document, first, the host computer 2 designates a range of a portion of the document to be printed using a pointing device or the like for which toner is to be saved, and stores the range data (the graph and the graph of FIG. 2). The printer driver software obtains (coordinates surrounding the natural image) and passes the information from the printer driver to the printer.

FIG. 3 is a block diagram showing the inside of a video circuit related to the present invention. Reference numeral 301 denotes a memory for reading a part of the print data stored in the drawing memory and temporarily storing the read data. When a gradation conversion table is used, this data is used as table select source data for selecting a table. Reference numeral 302 denotes a circuit that cuts out the data width W of the print data (table select source data) stored in the memory 301 into a width of N bits (in this example, N = 2 because the internal processing is 2 bits). Reference numeral 303 denotes a selector for selecting a gradation conversion table. Reference numeral 304 denotes a table used in the normal mode. In this example, since the internal processing is 2 bits, when one of the four tables is selected, 8-bit data registered in the table is read out. Converted to 8 bits.

Reference numeral 305 denotes a table used in the toner saving mode. When entering the toner saving mode, the internal processing is performed with 4 bits, and among the 16 tables that can be selected with 4 bits,
1 remaining except 4 tables used in normal mode
Two tables (three groups) can be used for the toner saving table. FIG. 4 shows a conversion table. As the normal mode table represented by 2 bits, four tables from Table 1 to Table 4 are prepared. In the toner-saving mode table, an index specifying a 2-bit group is added to 2-bit data. Four toner saving tables, Table 1 to Table 4, are prepared for each of three groups from toner saving 1 group to toner saving 3 group.

Reference numeral 306 denotes a sequencer for controlling the inside of the video circuit. For the area in which the toner saving mode is designated, the video control circuit 306 sets the bit width cut out from the table select source data having the data width W by the bit cutout circuit 302 to 4 bits. The bit cutout circuit 302 cuts out with a width of 4 bits according to the setting. The video control circuit 306 also includes a horizontal counter that counts the number of dots in the horizontal direction of the print data, whether the pixel position to be counted belongs to the set range of the toner saving mode set by the host computer. 307 and a vertical counter 308 that counts the number of print lines in the vertical direction are monitored. If the area is in the toner saving mode, the above 4-bit width is set. Also, the tone conversion table selector 303 is set to use the toner saving table as the conversion table for the toner saving area. <Procedure of Printing in Toner-Saving Mode> Here, the procedure of control by the host computer and the printer from when a toner-saving area is set to an image by the host computer 2 until the image is printed will be described.

FIG. 8 shows a procedure for setting a toner-saving area by the host computer and executing the setting. First, a toner-saving area and its toner-saving mode are input from an input unit such as a pointing device or a keyboard (Step S).
801). Next, the coordinates of the pixel position of the input area and the mode are sent to the printer 1 (step S80).
2) Finally, send the print data to the printer (step S)
803).

FIG. 9 shows the procedure for storing image data in the printer that has received the data sent in steps S802 and S803. First, the toner saving area and the mode sent in step S802 are received and stored (step S901). Next, the print data sent in step S803 is received (step S902), and the two most significant bits of each dot are selected as print data of each dot (step S903). Next, based on the information on the area received in step S901, it is determined whether the dot is a toner-saving area, and if so, two bits representing the toner-saving mode are added above the two bits, and the print data is printed. Is stored in the drawing memory (step S905). If the area is not the toner saving area, the second most significant bit is stored as it is in the second memory (step S906). In this way, print data including data indicating the toner saving mode is created and stored for each dot in the print data.

The processing in FIG. 9 may be performed in the host computer between steps S802 and S803 in FIG. 8, and then the print data may be sent to the printer.

The print data stored in the drawing memory 102 is sent to the engine by the video control circuit 103 and printed out.

FIG. 10 shows a control procedure for controlling the switching between the toner saving mode and the normal mode by the video control circuit 306. First, the horizontal counter 307 and the vertical counter 3
The value 08 is read (step S101), and it is determined whether the image area to be printed at present is set to the toner saving mode (step S102). This is step S
What is necessary is just to use the data stored in 901.

If the toner saving mode is set, the bit width cut out by the bit cutting circuit 302 is set to 4 bits (step S103), and the table selected by the gradation conversion table selector 303 is set as the toner saving table (step S103). S104).

If the mode is the normal toner mode, the bit width cut out by the bit cutout circuit 302 is set to 2 bits (step S105), and the table selected by the gradation conversion table selector 303 is set to the normal table (step S105). Step S106).

This step is repeated until the image data is completed.

The image data converted into the 8-bit gradation data as described above is input to the engine 104 and printed out. Only the designated area is printed in the toner saving mode, and the other area is not printed. Can be printed as usual. If a value is set in the toner saving table so that the density is converted to be lower than that in the tone conversion table in the normal mode, a desired toner saving area can be set and the toner consumption there can be reduced. . Further, for example, if the density is switched step by step for each group, it is possible to make a distinction depending on how clear the printing needs to be for each group, and it is possible to print at a density corresponding to the distinction.

Further, image data of 2 bits per pixel in the normal mode and 4 bits per pixel in the toner saving mode are cut out from W-bit width data and used as table select source data, and converted into 8-bit gradation data. Can be converted. Therefore, the image data created or read by the host computer is transferred to the printing apparatus 1.
When storing in, the toner saving area is set to 1
Although 4 bits per pixel, it is sufficient to store 2 bits per pixel for the normal mode area, and a large storage capacity is not required in the normal mode. [Second Embodiment] In the first embodiment, print data (table selection data) is directly processed. In the second embodiment, the toner-saving portion is detected in hardware without processing the source of the print data. FIG. 5 shows a block diagram of the video control circuit 103. As described above, in the case of internal 4-bit processing, three groups of toner saving modes can be prepared in addition to the normal table by changing the upper 2 bits. In the present embodiment, toner saving 1
3 are set in the video control circuit 103, the upper 2 bits are forcibly added to the cut out 2 bits of the source data according to the set toner saving mode. Make a table selectable.

In FIG. 7, the outer frame represents a sheet, and a portion surrounded by a thick black line is an area where toner saving is desired. Further, the area A is the toner saving 2 and the area B
Is toner saving 1. Points V1 to V4 indicated by dotted arrows in FIG. 7 are y (vertical) coordinates of a range for specifying toner saving, and H1 to H8 are x (horizontal) coordinates. Reference numerals 508 and 511 in FIG. 5 are registers for storing y and x coordinates. Each can be set up to a maximum Y vertically and a maximum X horizontally. Naturally, if the driver software exceeds the maximum values in the vertical and horizontal directions when acquiring these position data,
This prompts the user to reset the toner saving range. The diagram on the right side of FIG. 7 illustrates a change point of the toner saving mode in the horizontal direction at the vertical point V2. At point V2, there are four changing points in the horizontal direction, and it can be seen that two types of toner saving modes 1 and 2 are used. Therefore, the vertical point V indicates the number of horizontal change points, that is, the point at which the number of horizontal points included in the line changes. Therefore, in the register for setting V2, the y coordinate and the number of horizontal points H included in the line are set. Therefore,
During the period from V2 to V3, H3 to H6 are repeatedly switched and printed for each line. For the horizontal point H, for example, in the case of H3, the x coordinate and mode information after that point are set. In H3, the toner-saving 1 mode, that is, information in which the upper two bits in FIG. 4 are 01 is set. When the vertical and horizontal point registers set by the video control circuit 507 in FIG. 5 match the vertical and horizontal counters, the match signal is input to the video control circuit 507 by the comparators 509 and 512 to switch to the next point. In addition, the bit conversion circuit 503 forcibly converts 2 bits to 4 bits according to the mode set in the horizontal point register. Here, in the case of the normal mode, 00 is forcibly added to the upper two bits. <Setting of toner-saving area> In the present embodiment, the setting of the toner-saving area is almost the same procedure as in the first embodiment. However, in the present embodiment, the print data itself stored in the drawing memory of the printer does not need to include data indicating the toner saving mode. Therefore, FIG.
Steps S904 and S905 in the above procedure are unnecessary, and the upper two bits of the image data may be used as it is as print data. For this reason, it is more convenient to perform this processing by the host computer than by the printer from the viewpoint of data transfer efficiency.

Also, in step S802 in FIG.
It is necessary to perform the processing shown in FIG. That is, a vertical point and a horizontal point as shown in FIG. 7 are calculated from simple coordinate data (step S1101), and the points are sent to the printer (step S1102).

Based on the vertical point and horizontal point set in this way, the toner-saving mode is controlled according to the following control procedure.

FIG. 12 shows the control procedure of the toner saving mode by the CPU 100 and the video control circuit 507. First, the CPU 100 sets the register H and the register V for setting the horizontal point and the vertical point.
And the register N for counting the number of times the mode is shifted in each line is set to 0 (step S120).
1). Next, it is determined whether the toner saving mode has been set (step S1202). If the toner saving mode is set for the image data to be printed, the CPU 100 sets the toner saving table 506, and stores the horizontal point and the vertical point in the registers 508 and 508 in the manner shown in FIG. 511 (step S1203). Here, the CPU 100
The video control circuit 507 is activated and its control is started (step S1204).

First, at the beginning of each line, it is determined from the input from the vertical comparator 509 whether or not the y-coordinate of the vertical point currently set in the vertical register 508 matches the value of the vertical counter 509 (step S1). S1205). If they match, the vertical register 50
8 is shifted by one, and the next vertical point is selected by the selector (step S1215). If they do not match, the horizontal point on that line is the same as the horizontal point on the previous line, so by returning the horizontal register by the number of shifts on the previous line,
The next horizontal register is returned to the horizontal register indicating the first horizontal point in the previous line (step S1206). At this time, the counter N for counting the number of shifts in the line is returned to 0 at the same time.

In each line, it is determined whether or not the x-coordinate of the horizontal point matches the value of the horizontal counter 513 (step S1207). If they match, it is determined that the horizontal point at which the mode is to be switched has been reached. The register 511 is shifted to a horizontal register indicating the next horizontal point (step S1208). If the shift has been made, one is added to the shift number N of the mode in the line (step S1209), and the bit conversion circuit 503 is stored in the horizontal register in accordance with the toner saving mode stored corresponding to the x coordinate of the horizontal point. Under control, a value indicating a 2-bit group is added to the upper part of the 2-bit image data.

If it is determined in step S1207 that they do not match, the upper two bits of data to be added by the bit conversion circuit are controlled to have the same value as the immediately preceding line (step S1216). Thereafter, control is performed so that 8-bit data is output from the gradation conversion table selector 504 according to the mode (step S1211).
Thereafter, it is determined whether the data to be processed is the last dot of the line (step S1212). If not, the horizontal point coincidence is repeated for the next dot from the test. It is determined whether there is (Step S1213). If not the last line,
The determination is repeated from the coincidence of the vertical points for the next line.

The 4-bit data obtained in this manner is converted into 8-bit data by selecting a table in the same manner as in the first embodiment, and is printed out from the printer engine.

According to the above procedure, when the host computer designates a toner-saving area, printing can be made stronger in the toner-saving mode only for the designated area.

Furthermore, in order to set the toner saving mode, the coordinate information indicating the area and the mode information are held independently of the image information. And can be handled without any change. Therefore, no extra storage capacity is required to realize the toner saving mode, and no extra work is required for processing the image data.

[0035]

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine) Machine, facsimile machine, etc.).

An object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0041]

As described above, according to the printing apparatus and the printing control method of the present invention, by providing a partial toner saving function, the area can be selectively selected even for one document. This makes it possible to set the target in the toner-saving mode, so that it is possible to create a document that is easy to read even in the toner-saving mode while saving toner.

[0042]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a printing system according to the present invention.

FIG. 2 is a diagram illustrating an example of a document in which a document and a picture are mixed.

FIG. 3 is a simplified block diagram illustrating the inside of a video circuit according to the first embodiment.

FIG. 4 is a diagram illustrating an example of a gradation conversion table including a toner saving table.

FIG. 5 is a simplified block diagram of the inside of a video circuit according to a second embodiment.

FIG. 6 is a diagram showing conversion from internal processing 2 bits to 4 bits.

FIG. 7 is a diagram illustrating a mechanism for setting a toner saving area according to the second embodiment.

FIG. 8 is a flowchart illustrating a procedure for setting a toner saving mode by a host computer according to the first embodiment.

FIG. 9 is a flowchart illustrating a procedure for storing print data by the printer according to the first embodiment.

FIG. 10 is a flowchart illustrating a control procedure by the video control circuit according to the first embodiment.

FIG. 11 is a flowchart illustrating a procedure for setting a toner saving mode by a host computer according to the second embodiment.

FIG. 12 is a flowchart illustrating a control procedure by a CPU and a video control circuit according to the second embodiment.

Claims (10)

[Claims] 1. A designating means for designating a desired toner-saving area from print data, determining whether a target dot of the print data is included in the specified area, and setting the target dot to a toner-saving mode based on the determination result. An adding unit that adds toner saving mode data indicating that the designated area does not include the dot of interest, and converts the data into density data corresponding to the print data. A printing apparatus comprising: a conversion unit that converts toner mode data into density data according to print data using the index as an index; and a printing unit that prints and outputs according to the density data converted by the conversion unit. 2. The apparatus according to claim 1, further comprising compression means for reducing the gradation of the print data and compressing the print data, wherein the conversion means uses the print data compressed by the compression means as the print data. The printing device according to the above. 3. The addition of the toner saving mode data by the adding means is performed on the print data compressed by the compression means, and the print data to which the toner saving mode data is added and the storage for storing the designated area. 3. The printing apparatus according to claim 2, further comprising a unit. 4. A storage unit for storing the print data compressed by the compression unit and the designated area,
3. The printing apparatus according to claim 2, wherein the addition of the toner saving mode data by the adding unit is performed on the print data stored by the storage unit. 5. The designating means calculates, for a designated area, a vertical point including a line of print data indicating a start point or an end point of each area and a horizontal point including a dot position for each line. 2. The printing apparatus according to claim 1, wherein the adding unit determines that the target dot is within a designated area based on the vertical point and the horizontal point. 6. A designating step of designating a desired toner-saving area from print data, determining whether a target dot of the print data is included in the specified area, and setting the target dot to a toner-saving mode based on the determination result. An additional step of adding toner-saving mode data indicating that the designated area does not include the dot of interest; if the target area does not include the dot of interest, the data is converted into density data corresponding to the print data; A print control method, comprising: a conversion step of converting toner mode data into density data corresponding to print data using the index as an index; and a printing step of printing and outputting according to the density data converted by the conversion step. 7. The method according to claim 6, further comprising a compression step of reducing the gradation of the print data and compressing the print data, wherein the conversion step uses print data compressed by the compression step as print data. The print control method described in the above. 8. The addition of the toner saving mode data in the adding step is performed on the print data compressed in the compression step, and the print data added with the toner saving mode data and the designated area are stored in a storage unit. 8. The print control method according to claim 7, wherein the print control method is stored and input to the conversion step. 9. The print data compressed in the compression step and the designated area are stored in a storage unit, and the addition of the toner-saving mode data in the addition step is performed by adding a line to the print data stored in the storage unit. 8. The print control method according to claim 7, wherein the print control is performed. 10. The specifying step calculates, for a specified area, a vertical point including a line of print data indicating a start point or an end point of each area and a horizontal point including a dot position for each line. 7. The printing control method according to claim 6, wherein the adding step determines that the dot of interest is within the designated area based on the vertical point and the horizontal point.