JP2001301240A - Color/black and white mode switching method, recording medium, and color tandem image forming device system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color/black and white mode switching technology optimum for a color tandem image forming device. SOLUTION: In a system including a host for supplying information to be printed per page unit, and a device connected therewith, black and white and color printing modes are switched optionally. For an image forming device, the black and white printing speed per one page, the color printing speed, and sum of the switching time from the color mode to the black and white mode and the switching time from the black and white mode to the color modem are calculated. If there is a section with continuous black and white pages, only in the case it is judged based on the black and white printing speed, the color printing speed, and the sum that the printing operation can be executed more quickly in the black and white with mode switching than the case of printing the section in the color mode, the section is printed in the black and white mode. That is, with the premise that the minimum number of pages in the section capable of providing a time needed for printing in the black and white mode with mode switching before and after the printing operation shorter than the case of printing in the color mode is N, in the case all the continuous N pages in the section divided by N pages from the start of the section are black and white, the continuous N pages are printed in the black and white mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a system relating to a tandem color image forming apparatus which requires time to switch between a color / black and white / printing mode, and more particularly to a printing speed in such a tandem color image forming apparatus system. Color / black and white in a single job to increase
The present invention relates to a technique for optimizing the switching of a print mode.

[0002]

2. Description of the Related Art A color tandem printer having image forming units for each of the printing colors Y (yellow), M (magenta), C (cyan) and K (black) depends on the color of the image to be printed. It is common to have both color print modes. Comparing the case where the same document is printed in the black and white mode and the color mode, the color mode requires much more time. The distinction of whether a document is black and white or color is referred to as the "color mode" of the document. When a color tandem printer prints a document (or document file) in which both black and white and color are mixed in the color mode, it takes time, and the Y, M, and C color image forming units are driven even when printing a black and white document. Therefore, the life of those image forming units is shortened. On the other hand, if the print mode is changed in accordance with the color mode of the original, for example, by changing the print mode for each page, and the color mode changes frequently, the time required for switching the print mode is reduced. May be reduced. Further, since the switching of the print mode involves the operation of the drive system, if the print mode is switched too frequently, the life of the components and units is shortened. As a prior art dealing with such a problem of switching the print mode according to the color mode of the document, Japanese Patent Application Laid-Open No. 11-3 is disclosed.
There is a technique described in Japanese Patent No. 4438. According to this, each time data of the switching time between each operation mode and one page output time in each mode is held, and the continuous printing is performed while the plurality of pages to be continuously printed are maintained in the current mode. The time required is compared with the time required to perform printing by executing the mode switching, and printing is controlled so that printing is performed in the current mode only when continuous printing in the current mode is faster. . In the embodiment, two consecutive pages are accumulated to determine the mode switching. Although this method is considered to be effective as a technical idea, since it is determined only on two pages, it is not always possible to realize optimal mode switching. In addition, in the case of the method of “printing in the current mode only when continuous printing in the current mode is earlier”, if the speed is the same when maintaining the current mode and when switching,
Will switch. In consideration of the life of components and units, it is preferable not to switch if it is not necessary to switch.

[0003]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a formalized color / monochrome mode switching method which guarantees optimal mode switching in both printing speed and life, and a color tandem using this method. An object of the present invention is to provide an image forming apparatus. An apparatus having a printing function, including a printer, a copying machine, a facsimile, and a multifunction apparatus having these functions, is referred to as an image forming apparatus.

[0004]

According to a first aspect of the present invention, there is provided a system including a print information source for supplying information to be printed in page units and a color tandem image forming apparatus connected to the print information source. A black-and-white printing speed and a color printing speed per page, and a switching time from the color mode to the black-and-white mode and a switching time from the black-and-white mode to the color mode for the image forming apparatus. Preparing a sum, and if there is a section consisting of continuous black and white pages in the information, switch the mode rather than print the section in color mode based on the black and white printing speed, the color printing speed and the sum. Only when it is determined that printing in black and white mode is faster, Characterized in that it comprises the steps of printing, and a step of printing by the all color mode unless the. The color / monochrome mode switching method according to claim 2 is the method according to claim 1, wherein the time required to perform mode switching before and after printing and printing in monochrome mode is shorter than that in printing in color mode. When the number of pages is N, the step of printing in the black-and-white mode is to separate N pages from the beginning of the section, and if all the consecutive N pages are black and white, the continuous N pages are printed in the black-and-white mode. The method includes a step of printing. The color / black and white mode switching method according to claim 3, wherein the printing in the black and white mode is performed when the color page appears in the process of inspecting the color of the N consecutive pages. After printing in black and white mode the black and white pages up to the appearing color page, switching to the color mode is further included.

According to a fourth aspect of the present invention, in a computer which communicates with a color tandem image forming apparatus and supplies information to be printed to the color tandem image forming apparatus in units of pages, the computer switches between a monochrome and a color printing mode. A computer-readable recording medium on which a program is recorded, wherein the storage medium includes a monochrome printing speed and a color printing speed per page relating to the image forming apparatus, a switching time from a color mode to a monochrome mode, and If there is a section composed of continuous black and white pages in the information and each data of the sum of the switching time to the mode, based on the black and white printing speed, the color printing speed and the sum, the section is set in the color mode. Even if you switch modes, printing in black and white mode is faster than printing. A routine for controlling the image forming apparatus so that the section is printed in the black and white mode and a routine for controlling the image forming apparatus so that all sections are printed in the color mode except for the above case are recorded only when It is characterized by. The computer-readable recording medium according to claim 5 is the computer-readable recording medium according to claim 4, in which the time required to perform the mode switching before and after printing and printing in the black and white mode is shorter than in the color mode. When the number of pages is N, the routine for printing in the monochrome mode is divided into N pages from the beginning of the section, and when all the consecutive N pages are monochrome,
The image processing apparatus further includes a routine for controlling the image forming apparatus to print the continuous N pages in the monochrome mode. The computer-readable recording medium according to claim 6, wherein in the black-and-white mode printing routine, a color page appears in the course of inspecting the color of the N consecutive pages. The method further includes a routine for controlling the image forming apparatus to switch to the color mode after printing the monochrome page up to the appearing color page in the monochrome mode.

According to a seventh aspect of the present invention, there is provided a color tandem image forming apparatus for optimizing color / monochrome mode switching and printing information to be printed supplied in page units.
Concerning the image forming apparatus, each data of the black-and-white printing speed and the color printing speed per page, and the sum of the switching time from the color mode to the black-and-white mode and the switching time from the black-and-white mode to the color mode; If there is a section consisting of black and white pages, based on the black and white printing speed, the color printing speed and the sum, it is faster to print in the black and white mode even if the mode is switched than to print the section in the color mode. Only when it is determined that the section has been printed, a black-and-white printing unit for printing the section in the black-and-white mode and a color printing unit for printing in the color mode in all other cases are provided. In the color tandem image forming apparatus in which the color / monochrome mode switching is optimized according to claim 8, the time required for performing the mode switching before and after printing and printing in the monochrome mode is longer than in the color mode. If the minimum number of pages in the section that can be shortened is N, the monochrome printing means separates N pages from the beginning of the section, and if all the consecutive N pages are monochrome, the continuous N An N-page printing unit for printing a page in a monochrome mode is included. A color tandem image forming apparatus in which color / monochrome mode switching is optimized according to claim 9 is the color tandem image forming apparatus according to claim 8, wherein the monochrome printing means inspects the color of the continuous N pages. Appears, the method further includes a black-and-white printing ending means for switching to the color mode after printing the black-and-white pages up to the preceding color page in the black-and-white mode.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention and the accompanying drawings. When the same element is shown in a plurality of drawings, the same reference numeral is given. (Embodiment 1) FIG. 1 is a schematic diagram showing an overall configuration of an image forming apparatus system according to a first embodiment of the present invention. In FIG. 1, an image forming apparatus system 1 according to the present invention includes a host computer 100, Centronics,
The image forming apparatus 200 is connected to the host computer 100 via a general-purpose I / F cable (not shown) such as USB or a network (not shown) such as TCP / IP. The host computer 100 includes a printer driver 101 corresponding to the image forming apparatus 200, and a document created by the host computer is sent to the image forming apparatus 200 and printed. The image forming apparatus 200 includes the controller 20
1. It comprises a printer engine controller 202 and a printer engine 203. The controller 201
The printer driver 101 receives a command converted into a print language, converts the command into a bitmap image on a file or page basis, and passes it to the engine controller 202. The engine controller 202 performs predetermined timing control of the data in consideration of an electrophotographic process, paper conveyance, and the like, and the printer engine 203 creates a latent image to be printed on a photoconductor, adheres toner, Transfer and fixation to the printing work. FIG. 2 is a diagram schematically illustrating a configuration example of the printer engine 203. In the figure, the printer engine 203 has print colors Y, M,
Four image forming units 301, 302, 30 for C and K
3, 304, a transport (or transfer) belt 305, a paper feed tray 306, and a paper discharge tray 307. FIG.
3A illustrates a state in which the printer engine 203 forms a color image, that is, a color mode. FIG. 3B illustrates a state in which the image forming unit 305 is moved downward by a special mechanism to form only a black and white image. A state separated from the reference numerals 301, 302, and 303, that is, a monochrome mode is shown. As described above, switching from the color mode to the black-and-white mode involves an operation of partially separating the transport belt 305 from the image forming unit. Therefore, the switching is simply referred to as “contact / separation switching”, and the opposite switching is referred to as “separation / contact switching”. And both are referred to as "contact / separation / separation switching".

Hereinafter, a method of switching between the color / monochrome mode according to the present invention will be described. In this embodiment, the mode switching is performed on a page basis. There is no other choice but to print the color portion of the original in color mode. The problem is how to print the part in black and white mode. The color / black and white mode switching method according to the present invention is described as follows, assuming that the color portion is printed in color. That is, for a page section in which the monochrome mode of the document is continuous (a section consisting of a series of pages that can be printed in the monochrome mode), the “contact / separation / contact / disconnection” is performed before and after printing, rather than printing this monochrome mode section in the color mode. The control is performed such that printing is performed in the black and white mode only when the required time is shorter when printing in the black and white mode by performing “switching”. Therefore, the length of the black and white mode section is N pages, the printing time per sheet in the color mode is Ta, the printing time per sheet in the black and white mode is Tb, and the time required for switching between approach / separation / separation. Is Tc, the principle of the present invention is:
It looks like this: That is, “if Ta × N ≦ Tc + Tb × N, print in color mode without switching modes, and if Ta × N> Tc + Tb × N, print in black and white mode even after switching modes.”・ (1) As described above, when printing in the color mode,
In the case where the required time is the same as when printing is performed in the black and white mode by performing the separation / contact switching, the number of times of switching is reduced by printing in the color mode, so that the life of the parts and units can be extended.

A solution obtained by changing the inequality sign of the inequality expression (1) into an equality equation and solving for N is given by N = Ni + d
When expressed as (d <1), the expression (1) is: "Print in black and white mode (by switching to contact / separation / separation) only when the black and white mode section is Ni + 1 page or more". ... It can be said that (2). Actually, if there is a black-and-white page following the color page, it is determined whether or not the black-and-white section is the Ni + 1 page or more. Therefore, as shown in FIG. 1, the printer driver 101 outputs an average color printing speed Ta (seconds / page), an average black-and-white printing speed Tb, and an approach / separation / separation switching time Tc (second) according to the model of the image forming apparatus 200. ) And Ni or Ni + 1 calculated based on these data. For example, Ta = 6 seconds, Tb = 2
In the case of the image forming apparatus in which the second and the contact / separation switching and the contact / separation switching require 5 seconds, that is, Tc = 10 seconds, the equation obtained from Expression (1) is 6 × N = 10 + 2 × N. N = 2.5. Therefore, in the case of this image forming apparatus, printing is performed in the monochrome mode only when the monochrome mode section is 3 (= 2 + 1) pages or more.

Hereinafter, the printing control operation of the printer driver of the color tandem image forming apparatus system according to the present invention will be described. The printer driver 101 of the host computer 100 determines the print mode specified by the user at the time of issuing the print command, issues a color mode instruction to 201 if the print mode is the color print mode, and 2 if the print mode is the monochrome print mode.
01 is instructed in the monochrome mode. FIG. 3 is a flowchart showing a print control operation performed by the printer driver 101 according to the present invention when the user specifies the automatic switching mode. In the case of the automatic switching mode, in FIG.
The printer driver sets the page counter P to 1 in step 402. While converting the document on page P into a page description language (step 404), it is determined whether page P is a monochrome document (step 406). If not black and white, the page P is determined to be the beginning of a color page section, and the process proceeds to step 407, where it is determined whether the value of the counter P is 1. If P = 1, it is a color page immediately after printing in monochrome mode in units of Ni + 1 pages, so the process proceeds to step 408, where the converted page P and an instruction of the color print mode are sent to the image forming apparatus 100, that is, the controller 201. . In response, the controller starts printing the page P in the color mode. Next, in step 410, the printer driver 101 determines whether or not there are any pages to be printed, and if not, ends the printing process in this mode. If it remains, the counter P is incremented (step 4).
12) While converting the page P into a page description language (step 414), it is determined whether the page P is a monochrome page (step 416). If it is not monochrome, the converted page P is sent to the controller 201. If the value of the counter P is not 1 in the judgment step 407, that is, if a continuous black-and-white page has been checked but a color page has appeared before reaching Ni + 1, the P- After the page data up to 1 is sent to the controller 201 (that is, printing is performed in the monochrome mode), the process proceeds to step 408.

If it is determined in step 416 that the page P is black and white, the document starts a black and white section from this page. Therefore, in order to determine whether or not the black and white section is at least Ni + 1 pages, the counter P is incremented by one. Is set and the process proceeds to step 432. In step 432, it is determined whether or not there are any pages to be printed. If not, the P page converted so far (step 420)
, And in this case, only one page) is sent to the controller 201, and the printing process in this mode ends.
The controller 201 prints the received page data without changing the mode, that is, in the color mode. If it is determined in step 432 that there are pages to be printed, the counter P is incremented in step 436, and the process returns to step 404. If the page P is black and white at step 406, then at step 430, the counter P
Is determined to have reached Ni + 1. If it has not reached, the process proceeds to step 432 to continue checking whether there is at least the Ni + 1 page in the black-and-white section, and the subsequent operations are omitted. If the counter P has reached Ni + 1 in step 430, in step 438 the data of the Ni + 1 page thus far converted and the instruction of the monochrome print mode are sent to the controller 201, and the process returns to step 402. When receiving the same print mode as the current print mode, the controller 201 ignores the print mode and continues printing in the current mode.

(Embodiment 2) In the first embodiment, the printer driver 101 of the host computer 100 performs the automatic switching mode between color and black and white, but this processing is performed by the controller of the image forming apparatus 200 itself. May be. FIG. 4 shows an embodiment in which the color / monochrome mode switching program 210 is provided in the printer controller 201a of the image forming apparatus 200a. In this case, the data of each page processed by the color / monochrome mode switching program 210 has already been converted into a page description language. Therefore, the operation performed by the program 210 is such that steps 404 and 414 are deleted from the flowchart of FIG.
01 operates according to the flow in the case where 01 is read by the printer engine controller 202. In this embodiment, the host computer may be a conventional one. The above is merely an example of the embodiment for the description of the present invention. Therefore, it is easy for those skilled in the art to make various changes, modifications, or additions to the above-described embodiment in accordance with the technical idea or principle of the present invention. Therefore,
The present invention should not be construed as being limited to the above-described embodiments, but should be construed in accordance with the appended claims.

[0013]

According to the first to third aspects, an optimal and formalized mode switching method can be obtained in consideration of the switching time of the color / monochrome mode in the color tandem image forming apparatus, so that the printing speed and the service life are improved. I do. According to the fourth to sixth aspects, the same effect can be realized by the printer driver on the host. According to claims 7 to 9,
Similar effects can be realized by the image forming apparatus itself.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of an image forming apparatus system according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams schematically illustrating a configuration example of a printer engine, in which FIG. 2A illustrates a state in which the printer engine forms a color image, that is, a color mode, and FIG. FIG. 9 is a view showing a state in which the image forming unit is separated by moving the 305 downward by a special mechanism, that is, a black and white mode.

FIG. 3 is a flowchart illustrating a print control operation performed by the printer driver according to the first embodiment of the present invention when a user designates an automatic switching mode.

FIG. 4 is a schematic diagram illustrating a configuration of an image forming apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

1 Image forming apparatus system 100 according to a first embodiment of the present invention 100 Host computer 101 Printer driver 200 Image forming apparatus 201 Printer controller 202 Printer engine controller 203 Printer engine 301 to 304 Image formation for printing colors Y, M, C and K Unit 305 Conveyor belt 306 Paper feed tray 307 Paper discharge tray 200a Image forming apparatus 201a according to the second embodiment of the present invention 201a Printer controller of image forming apparatus 200a 210 Color / monochrome mode switching program of controller 201a

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masahiro Kitayama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Mitsuru Sugiyama 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F term (reference) 2C087 AA15 AB05 AC08 BD01 BD46 CA05 DA03 5B021 AA01 BB01 LG07 5C079 HA09 HA13 HB03 LA01 LA31 NA11

Claims (9)

[Claims] 1. A method for switching a print mode between black and white and color in a system including a print information source that supplies information to be printed in page units and a color tandem image forming apparatus connected thereto. Preparing a black-and-white printing speed and a color printing speed per page for the image forming apparatus, and a sum of a switching time from the color mode to the black-and-white mode and a switching time from the black-and-white mode to the color mode; If there is a section consisting of black and white pages, based on the black and white printing speed, the color printing speed and the sum, it is faster to print in the black and white mode even if the mode is switched than to print the section in the color mode. Printing the section in black and white mode only when it is determined that And printing in a color mode. 2. The method according to claim 1, wherein the minimum number of pages in the section in which the time required for printing in the black and white mode is shorter by switching modes before and after printing than in the color mode is N. 5. The method according to claim 1, wherein the step of printing includes a step of printing the continuous N pages in a black and white mode when the continuous N pages are all black and white, with N pages being separated from the beginning of the section. 1. The method for switching color / monochrome mode according to item 1. 3. The method according to claim 1, wherein the step of printing in the black-and-white mode includes the steps of: if a color page appears in the course of inspecting the colors of the consecutive N pages, the black-and-white printing before the appearing color page. 3. The color / black and white mode switching method according to claim 2, further comprising the step of switching to the color mode after printing said page in the black and white mode. 4. A computer in which a program executed to switch a printing mode between black and white and color is recorded in a computer which communicates with a color tandem image forming apparatus and supplies information to be printed thereto in units of pages. A readable recording medium, the storage medium comprising: a black-and-white printing speed and a color printing speed per page relating to the image forming apparatus; and a switching time from the color mode to the monochrome mode and a switching time from the monochrome mode to the color mode. If there is a section consisting of continuous black and white pages in the information and the information, the mode switching is performed based on the black and white printing speed, the color printing speed and the sum, and printing the section in the color mode. Only if it is determined that printing in black and white mode is faster A computer recording a routine for controlling the image forming apparatus so as to print the section in the black and white mode, and a routine for controlling the image forming apparatus so as to perform printing in the color mode except for the above case. A readable recording medium. 5. The method according to claim 1, wherein the minimum number of pages in said section, in which the time required to print in black and white mode by switching modes before and after printing is shorter than that in printing in color mode, is N. A routine for printing in the mode is to divide the page by N pages from the beginning of the section,
5. The computer-readable recording medium according to claim 4, further comprising a routine for controlling the image forming apparatus to print the continuous N pages in a monochrome mode when all pages are monochrome. 6. When a color page appears in the course of inspecting the colors of the N consecutive pages, the routine for printing in the black and white mode, if the color page appears before the appearing color page. 6. The computer-readable recording medium according to claim 5, further comprising a routine for controlling the image forming apparatus to switch to the color mode after printing the page in the monochrome mode. 7. A color tandem image forming apparatus which prints information to be printed supplied in page units by optimizing color / monochrome mode switching, and relates to the image forming apparatus, a black-and-white printing speed and color per page per page. The printing speed, and the data of the sum of the switching time from the color mode to the black-and-white mode and the switching time from the black-and-white mode to the color mode, and the black-and-white printing speed when there is a section consisting of continuous black and white pages in the information. Based on the color printing speed and the sum, the section is printed in the black and white mode only when it is determined that printing in the black and white mode is faster even if the mode is switched than printing the section in the color mode. A black-and-white printing unit, and a color printing unit for printing in a color mode in all other cases. A color tandem image forming apparatus that optimizes color / monochrome mode switching. 8. When the minimum number of pages in the section is shorter than the time required for printing in the black and white mode by switching modes before and after printing rather than in the color mode, and when the number of pages is N, the monochrome printing is performed. Means is N from the beginning of said section
8. An N-page printing means for separating each page and printing the continuous N pages in a black-and-white mode when the continuous N pages are all black and white.
A color tandem image forming apparatus in which the switching of the color / monochrome mode described above is optimized. 9. When a color page appears in the process of inspecting the color of the continuous N pages, the monochrome printing means copies the black and white pages before the appearing color page. 9. The color tandem image forming apparatus according to claim 8, further comprising a black-and-white printing ending unit for switching to a color mode after printing in a monochrome mode.