JP2001277555A - Printing data conversion apparatus, printer using the same, image data supply apparatus, and printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly suppress the quantity of a printing agent to a total quantity restriction range of the printing agent without damaging color reproducibility when the total quantity of the printing agent applied to a predetermined unit region (pixel, dot, etc.) must be restricted by the kind of a printing medium in a printer for performing printing by bonding coloring matters of C, M, Y and K to the printing medium. SOLUTION: The removing quantities (d) of C, M and Y are calculated on the basis of the total quantity restriction value determined by the kind of the printing medium and these (d) values are compared with the minimum values of values of C, M and Y (S7). When the calculated (d) values are less than the minimum values of C, M and Y, processing for subtracting the (d) values from the inputted values of C, M and Y to replace the subtracted values with the respective values is performed (S11) and, when the (d) values are larger than the minimum values of C, M and Y, processing for lowering chroma according to a proper ratio is performed (S23, S25).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print data processing apparatus, and a printing apparatus, a print data supply apparatus, and a printing system using the same.

[0002]

2. Description of the Related Art With a recent increase in the resolution of a printing apparatus, a method of expressing various colors by applying printing agents of a plurality of colors substantially identically on a printing medium has been adopted.
When implementing such a method in a printing system, the color of an image input from an image data supply source and the color of an image output by a printing apparatus are made as equal as possible, that is, a color for improving color reproducibility. The intervention of an image processing system for matching is essential.

The functions of such an image processing system include input image data represented by luminance data of red (R), green (G), and blue (B) for cyan (C), magenta, In addition to the function of converting the print data into density data of (M) and yellow (Y), the function of extracting a black (K) component from the converted C, M, and Y data (BGR) and the function of replacing with K A function (UCR) for removing the amount of C, M, and Y components related to the added amount is included.

[0004]

However, due to the relationship between the properties of the printing agent and the type of the printing medium and restrictions on the hardware of the printing apparatus, even if the same image is printed under the same conditions, the following is required. Such inconvenience may occur.

[0005] For example, in an ink jet printing apparatus using ink as a printing agent, the state in which the ink adheres to or penetrates the printing surface differs depending on the type of print medium due to the properties of the ink. Therefore, in the above-described image processing system, even if the ejection amount of each color ink is determined by performing fixed or uniform BGR or UCR on the same input data, depending on the type of print medium to be printed, Absorption is not performed well, and so-called ink overflow may occur.

Also, in an electrophotographic printing apparatus such as a laser beam printer using a toner as a printing agent, the toner may peel off depending on the type of print medium.

Therefore, it is highly desirable that the total amount of the printing agent is appropriately limited in accordance with the restrictions on the hardware of the apparatus such as the type of the printing agent and the means for applying the printing agent, or the type of the printing medium.

Accordingly, the present invention provides a printing apparatus which performs printing by adhering dyes of a color printing agent such as C, M, Y, and K to a printing medium and performs printing in a predetermined unit area due to restrictions of the printing medium or the printing apparatus. If the total amount of printing agent applied per pixel (dots, dots, etc.) should be limited, the purpose is to ensure that the amount of printing agent used for color expression is appropriately set within the total amount limit .

[0009]

For this purpose, the present invention provides:
A print data conversion apparatus or method for converting and supplying input print data of each color to printing means for performing printing by applying each color printing agent of cyan, magenta, yellow and black to a print medium. Formula 1: LIMIT = Max (100, K (d) + K) + (Cd) + (Md) + (Yd) (C, M, Y, K: the inputted cyan, magenta, yellow and The usage amount of each color printing agent for a predetermined unit area of the print medium based on black print data (0 to 100%), LIMIT: total amount limit of printing agent acceptable in the predetermined unit area (up to 400%), K (d): C,
Means or a process for determining a d value that satisfies the value of K at which M and Y have the same lightness as the color of d%), and determine whether the d value is equal to or less than the minimum values of the C, M, and Y Means or step, and when it is determined by the means or step that the value is equal to or less than the minimum value, the second equation: K ← Max (100, K (d) + K), C ← Cd, M ← Md, Y A means or a step of converting and supplying the print data according to Yd, and, when the d value exceeds the minimum value, performing the conversion of the second expression using the minimum value as the d value, and performing the conversion after the conversion. The third formula: A means or a process for finding an r value satisfying r = ((C + M + Y + K) -LIMIT) / (C + M + Y), and the r value, the fourth formula: Means for converting and supplying the print data in accordance with K ← K, C ← CC × r, M ← MM × r, and Y ← YY × r.

Further, the present invention is a printing apparatus for performing printing using a printing means for applying a printing agent of each color of cyan, magenta, yellow and black to a printing medium, comprising the above-mentioned print data conversion apparatus. It is characterized by the following.

Here, the printing means may have a print head for discharging ink as the printing agent for each color onto the printing medium.

Alternatively, the printing means may include means for adhering the toner as the printing agent for each color to the print medium.

Further, the present invention is to supply image data relating to printing to a printing apparatus which performs printing using printing means for applying printing agents of respective colors of cyan, magenta, yellow and black to a printing medium. An image data supply device according to any one of the preceding claims, further comprising the above-described print data conversion device.

Further, the present invention provides a printing apparatus for performing printing using printing means for applying a printing agent of each color of cyan, magenta, yellow and black to a printing medium, and an image related to printing on the printing apparatus. A print system including an image data supply device for supplying data, the print system including the print data conversion device described above.

[0015] In addition, the present invention resides in a storage medium storing a program for executing the above-described print data conversion method by a computer.

In this specification, "print" means not only a case where significant information such as characters and figures are formed, but also a wide range of images,
This also applies to the case of forming a pattern, a pattern, and the like.

Here, the term "print medium" includes not only paper used in a general printing apparatus but also a wide range of materials such as cloth, plastic film, metal plate and the like which can accept a printing agent such as ink or toner. Shall say.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

(Print System) FIG. 1 shows a configuration example of a control system of a print system including a host device serving as a supply source of image data relating to printing and a printing device executing a print process on the supplied image data. FIG.

First, in the host device 10 which can be in the form of a personal computer or a workstation, 101 is a CPU serving as a main control unit, 103 is a ROM storing required programs and fixed data, and 105 is an operation of an application program. And a RAM used for temporary storage of various data and other work. Also, 1
Reference numeral 07 denotes a hard disk device used for storing various application programs and data such as a program for creating and editing image data, reference numeral 109 denotes a floppy (registered trademark) disk device, and reference numeral 111 denotes a device for reading stored information from a CD-ROM.

Reference numeral 113 denotes a display unit such as a CRT or LCD, 115 denotes an input unit having a keyboard and a pointing device such as a mouse, and 117 denotes a switch for turning on and resetting the power of the apparatus. 119 is an interface for exchanging information such as data and commands with the printer 20, and 121 is a network (N
/ W) interface.

Next, in the printing apparatus 20, 201
Denotes a CPU serving as a main control unit; 203, a ROM in which necessary programs for controlling the printing operation, fixed data, and the like are stored; 205, a RAM used for temporarily storing various data such as image data and other work; . Also,
Reference numeral 207 denotes a printer engine, which includes a print head and its main scanning system, a print medium transport system (sub-scanning system), and the like, which will be described later with reference to FIG.

Reference numeral 213 denotes a display unit such as an LCD or LED for displaying a required message to the user.
A switch is used to switch on / off the on-line / off-line state with the host device 10 in addition to turning on and resetting the device. A conversion unit 217 converts the image data supplied from the host device 10 into print data for causing the printer engine 207 to perform a print operation.

Reference numeral 209 denotes an interface for exchanging information such as data and commands with the host device 10.

Reference numeral 219 denotes a setting unit for setting necessary information for limiting the total amount of the printing agent. The setting unit 219 is used for holding information relating to hardware restrictions of the printer engine 207 or for printing. It may be a means for determining the type of the print medium. In the latter case, it has an optical sensor placed on the transport path of the print medium, and irradiates light to the print surface prior to the printing operation and measures the reflectance of the print surface to make it plain paper or coated paper. Paper, OHP paper, or the like, or a form that accepts a user's designation of a print medium can be used.

FIG. 2 is a schematic perspective view showing an example of a schematic configuration of a serial printing type color ink jet printer as an example of the printer 20 applicable to the system of this embodiment.

In the figure, a nozzle (discharge port for discharging ink) for discharging each color ink such as yellow (Y), magenta (M), cyan (C) and black (K) is provided on a carriage 204. Print heads 200 a, 2 b, 2 b, 2 b, 2 b, 2 b, 2 b, 2 b, 2 b, 2 b, and 2 b) include liquid paths communicating with the discharge ports and discharge energy generating means such as a piezo element or a heating resistor provided in each liquid path.
00b, 200c, and 200d are mounted with the ejection port forming surface facing the print medium P. Further, the carriage 204 is connected to a timing belt 223 stretched between pulleys 222 to transmit the driving force from the pulse motor M, and the carriage 204 moves in the direction of arrow A in accordance with the driving of the pulse motor M. Reciprocate (main scanning). In this process, a printing operation is performed by discharging ink from nozzles of the print head in accordance with a discharge signal given at a predetermined timing.

In FIG. 2, reference numerals 225, 226 and 227, 228 denote conveying rollers extending parallel to the guide shaft 221 on the far side and near side in the drawing of the scanning area of the carriage 204, which are not shown. Driven by the sub-scanning motor, the print medium P is nipped and conveyed.

(Image Processing Unit) FIG. 3 shows an example of the configuration of an image processing unit according to the present system. The illustrated image processing unit can be provided as a component of the conversion unit 217 on the printing apparatus 20 side. Further, an image processing program (ROM 203) for executing some functions of the configuration by the printing apparatus 20.
) Can be executed as a function.

In FIG. 3, reference numeral 303 denotes a luminance / density conversion unit which converts image data represented by luminance data of red (R), green (G) and blue (B) into cyan (C), A function of converting the print data into density data of magenta (M) and yellow (Y) is executed.

The print data conversion unit 305 basically extracts a black (K) component from C, M, and Y data (B
A black generation unit that performs a GR (GR) function; and a UCR unit that performs a (UCR) function that removes an amount of C, M, and Y components related to the amount replaced with K. The print data conversion unit 305 of this embodiment variably controls each color of C, M, Y, and K based on the setting contents of the setting unit 219, that is, the data of the printing agent total amount limit value determined by the restrictions of the print medium and the printer engine. The amount of ink used is set for each unit area.

Reference numeral 307 denotes a binarization processing unit which turns on / off the driving of each nozzle in each region for each color head so that the ink usage amount set for each unit region by the print data conversion unit 305 is obtained. And so on.

In connection with the above configuration, the host device 1
At 0, an input γ conversion unit for correcting the light emission characteristics of the CRT used as the display unit 113 and an arithmetic processing function for correcting the turbidity of the color when the ink as the printing agent is superposed (subtractive color mixing) are executed. A masking correction unit, a correction unit that performs a function of performing output γ correction, and the like may be provided.

(Print Data Conversion Processing) FIG. 4 is a flowchart for explaining the operation of the print data conversion unit 305 in FIG. In the following processing, various values obtained in the process of outputting image data to the printer engine may be obtained by performing predetermined operations, and may be obtained by providing a predetermined lookup table and referring to the table. It may be.

First, in step S1, the setting unit 21
9, necessary information for limiting the total amount of the printing agent is fetched. When the print data conversion unit 305 is provided on the host device 10 side and the setting unit 219 is provided on the printing device 20 side, the information can be transmitted and received via the interfaces 209 and 119.

Next, in step S2, the total amount limit of the printing agent is obtained based on the information (step S2).
3). Here, the total amount limit value is a value determined by the type of the print medium, the configuration of the printing apparatus, and the like, and can be obtained in advance by experiments or the like corresponding to various conditions.
Then, the information for performing the total amount limitation and the total amount limit value are associated and tabulated, and the corresponding total amount limit value can be acquired according to the information fetched from the setting unit 219.

In this example, the total amount limit value is defined as a predetermined unit area (for example, a pixel composed of a predetermined number of ink dots or a dot composed of a predetermined number of pixels, for example). Is a limit value at which inconvenience such as ink overflow from the area does not occur when C, M, Y, and K are applied to the area from the print heads 200a, 200b, 200c, and 200d, respectively.
Is expressed as the maximum value when 100% of the ink is ejected, and is usually 100 to 400%.

In step S5, C, M, and Y corresponding to a predetermined unit area are output from the luminance / density conversion unit 303.
And the black (K) component is extracted.

Then, in step S7, d satisfying the following equation is satisfied.
Find the value. LIMIT = Max (100, K (d) + K) + (Cd) + (Md) + (Yd) (1) where LIMIT is the total amount limit value (100 to 400%) , C, M,
Y and K are used amounts of each color ink (0 to 100%), and K (d) is a value of K at which C, M and Y have the same lightness as the color of d%.

Next, in step S9, the obtained d value is compared with the minimum values of the C, M, and Y data. Here, when the obtained d value is equal to or less than the minimum value of C, M, and Y, the amount falls within the total amount limit value LIMIT only by performing the next conversion process, and the ink does not overflow. K ← Max (100, K (d) + K), C ← Cd, M ← Md, Y ← Yd (2) That is, in this case, the input C, M, A process of subtracting the value of d from the value of Y and replacing the data with each data is performed (step S11).

On the other hand, since each term on the right side of the equation (1) cannot be negative, the d value obtained in step S7 is C, M, Y
If it is larger than the minimum value of
Will not fall within the total limit LIMIT. Therefore, in this example, the following processing is performed to reduce the saturation so as to keep the total amount within the limit value.

That is, first, d is converted into the minimum value of C, M, and Y to convert the expression (2) (step S21), and a ratio r for decreasing the saturation is further obtained from the converted value by the following expression. (Step S23). r = ((C + M + Y + K) -LIMIT) / (C + M + Y) (3) Based on the obtained r value, the following conversion is performed to determine each color data (step S25). K ← K, C ← CC × r, M ← M−M × r, Y ← Y−Y × r (4) Further, the above processing is performed every minute corresponding to a predetermined unit area. The process is sequentially executed for all input image data (step S27).

That is, steps S21 to S21 in this example
The conversion process of S25 is performed when a value larger than the set amount (total amount limit value) of the printing agent (toner, ink, etc.) occurs before the printing is actually performed by the printing apparatus 20. . If the total amount limit is not exceeded, such conversion processing is not performed at all. Even if the total amount exceeds the limit, only the minimum necessary conversion is performed.
The color change of the output image is small.

(Others) In the above description,
Although the image data processing unit including the print data conversion unit 217 is provided on the printer 20 side, it may be provided on the host device side. Further, a part of the configuration and the rest may be provided on the host device 10 side and the printing device 20 side, respectively, and the configuration shown in the figure may be realized as the whole system.

When all or a part of the illustrated configuration is provided in the host device 10 in the form of a computer, for example, the function can be executed as a function of a printer driver installed in the host device 10. Alternatively, in addition to executing the functions of the illustrated configuration by using such software, a part or all of the functions may be realized by hardware.

In the above-described configuration of the printing system, a computer is used as the host device 10, but any other configuration may be used as long as it has a configuration capable of supplying image data to the printing device. . For example, a digital camera or an image reader can be used.

Further, the printing apparatus 10 is not limited to the apparatus having the printer engine 207 as shown in FIG. 2, but may be any other apparatus having a configuration in which the total amount of the printing agent should be appropriately restricted during the printing operation. May have a printer engine based on the above method. That is, the present invention is applicable not only to an ink-jet method in which ink overflow or the like may occur depending on the type of print medium, but also to an apparatus having an electrophotographic printing means such as a laser beam printer in which the adhered toner may peel off. The application is valid.

In addition, in the example of FIG. 2, an apparatus which enables full-color printing using four color printing agents of yellow, magenta, cyan and black is shown, but the colors and types of the printing agents are not limited to this. Not done. For example, FIG.
In the above configuration, a printing agent having a different density for performing halftone expression or a printing agent for enabling formation of a photographic image may be further used.

In addition, the form of the printing apparatus is not only used as an image output terminal of an information processing apparatus such as a computer, but also a copying apparatus combined with a reader or the like.
Further, a facsimile apparatus having a transmission / reception function may be used. Further, the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but can be applied to an apparatus (for example, a copier or a facsimile device) including one device. May be applied.

An object of the present invention is to supply a medium in which a program code of software for realizing required functions as illustrated in FIGS. 2 and 3 is supplied to a printing system, and a computer main body (or CPU) of the system. And MPU) and a main control unit (CPU or the like) of the printing apparatus execute processing based on the program code.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, 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, C
DR, magnetic tape, nonvolatile memory card, ROM
Etc. can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also an OS or the like running on the computer is actually executed based on the instructions of the program code. And a part of the entire process is performed, and the process realizes the function of the present embodiment.

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 instruction of the program code, The case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing, and the function of the present embodiment is realized by the processing.

Further, a medium in which software program codes for realizing the functions of the above-described embodiments are recorded is supplied to a system control computer or individual workstations and network printers. By reading the program code stored in the medium and executing the program, or based on the instructions of the program code, the operating system or the like running on the workstation or the network can perform part or all of the actual processing. It is also achieved by doing everything.

In this case, the program code itself read from the storage medium realizes the function according to the technical idea of the present invention, and the present invention also resides in the storage medium storing the program code. As a storage medium for supplying the program code, for example,
Various forms of magnetic disk, optical disk, IC card,
A ROM or the like can be used.

[0057]

As described above, according to the present invention,
2. Description of the Related Art In a printing apparatus that performs printing by adhering a dye of a color printing agent such as C, M, Y, and K to a printing medium, the total amount of the printing agent applied per predetermined unit area due to a limitation of the printing medium or the printing apparatus. If it is to be limited, the amount of printing agent can be appropriately controlled within the total amount limit without impairing color reproducibility.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a control system of a print system including a host device serving as a supply source of image data related to printing and a printing device performing a print process on the supplied image data.

FIG. 2 is a schematic perspective view showing a schematic configuration example of a color inkjet printer using a serial print method as an example of a printer applicable to the print system of FIG.

FIG. 3 is a block diagram illustrating a configuration example of an image processing unit according to the print system of FIG. 1;

FIG. 4 is a flowchart illustrating an operation of a print data conversion unit in FIG. 3;

[Explanation of symbols]

Reference Signs List 10 host device 20 printing device 101, 201 CPU 103, 203 ROM 105, 205 RAM 119, 209 interface 207 printer engine 217 conversion unit 219 printing agent total amount restriction information setting unit 200a, 200b, 200c, 200d print head 303 brightness density conversion Unit 305 Print data conversion unit

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2C056 EA09 EA11 EB13 EB45 EC07 EC72 EC76 EC79 EE03 EE09 EE14 FA10 2C262 AA02 AA24 BA02 BA07 BA09 BA16 BA19 DA06 FA20 5C074 AA08 BB16 CC26 DD23 EE08 EE11 FF15 HH04

Claims (8)

[Claims] 1. A print data conversion device for converting and supplying input print data of each color to printing means for performing printing by applying each color printing agent of cyan, magenta, yellow and black to a print medium. And the first formula: LIMIT = Max (100, K (d) + K) + (Cd) + (Md) + (Yd) (C, M, Y, K: the inputted cyan and magenta , Use amount of each color printing agent for a predetermined unit area of the print medium based on print data of yellow and black (0 to 100%), LIMIT: total amount limit of printing agent acceptable in the predetermined unit area (up to 400%) ), K (d): C,
Means for determining a d value that satisfies the value of K at which M and Y have the same lightness as the color of d%) and means for determining whether or not the d value is equal to or less than the minimum value of the C, M, and Y If the means determines that the print data is equal to or smaller than the minimum value, the print data is calculated according to the following equation: K ← Max (100, K (d) + K), C ← Cd, M ← Md, Y ← Yd. Means for converting and supplying, when the d value exceeds the minimum value, the minimum value is set to d
The value of the second equation is converted as a value, and the value after the conversion is an r value that satisfies the third equation: r = ((C + M + Y + K) -LIMIT) / (C + M + Y) And a means for converting and supplying the print data in accordance with the fourth equation: K ← K, C ← CC × r, M ← MM × r, Y ← YY × r according to the r value. A print data conversion device. 2. A printing apparatus for performing printing using printing means for applying a printing agent of each color of cyan, magenta, yellow and black to a print medium, comprising the print data conversion apparatus according to claim 1. A printing apparatus, characterized in that: 3. The printing apparatus according to claim 2, wherein the printing unit has a print head that discharges ink as the printing agent for each color onto the printing medium. 4. The printing apparatus according to claim 2, wherein the printing unit includes a unit that causes the toner as the printing agent for each color to adhere to the print medium. 5. An image data supply for supplying image data relating to printing to a printing apparatus which performs printing using printing means for applying printing agents of respective colors of cyan, magenta, yellow and black to a printing medium. An image data supply device, comprising: the print data conversion device according to claim 1. 6. A printing apparatus for performing printing using printing means for applying a printing agent of each color of cyan, magenta, yellow and black to a printing medium,
A print system comprising an image data supply device for supplying image data relating to printing to the printing device, comprising: the print data conversion device according to claim 1. . 7. A print data conversion method for converting and supplying input print data of each color to printing means for performing printing by applying each color printing agent of cyan, magenta, yellow and black to a print medium. Where LIMIT = Max (100, K (d) + K) + (Cd) + (Md) + (Yd) (C, M, Y, K: the input cyan, magenta, The usage amount of each color printing agent for a predetermined unit area of the print medium based on the print data of yellow and black (0 to 100%), LIMIT: the total amount limit of the printing agent acceptable for the predetermined unit (up to 400%), K (d): C, M, Y is d%
Determining a d value that satisfies the minimum value of C, M, and Y; and a step of determining whether the d value is equal to or less than the minimum values of C, M, and Y. If it is determined that the value is equal to or less than the value, the print data is converted and supplied according to the following equation: K ← Max (100, K (d) + K), C ← Cd, M ← Md, Y ← Yd And if the d value exceeds the minimum value, the minimum value is set to d.
The value of the second equation is converted as a value, and the value after the conversion is an r value that satisfies the third equation: r = ((C + M + Y + K) -LIMIT) / (C + M + Y) And a step of converting and supplying the print data in accordance with the fourth equation: K ← K, C ← CC × r, M ← MM × r, Y ← YY × r according to the r value. A print data conversion method. 8. A storage medium storing a program for causing a computer to execute the print data conversion method according to claim 7.