JP2002357941A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of forming at least a monochrome image even when the amount of at least one of three remaining toners in cyan, magenta, and yellow is insufficient. SOLUTION: The process in which whether image formation can be carried out is determined by the amounts of remaining toners is divided into a process in which image formation can be carried out is determined by the amount of remaining black toner and a process in which image formation can be carried out is determined by the amounts of toners other than the black toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus, and more particularly to an image forming apparatus capable of forming an image even when a developer of a specific color is insufficient.

[0002]

2. Description of the Related Art An example of a conventional image forming apparatus will be described with reference to FIG. 3, and an example of a processing flow in the conventional image forming apparatus will be described with reference to FIG. FIG. 3 is a sectional view of the image forming apparatus L. Sheets PS, which are recording media before printing, stored in a paper feed cassette (not shown) are fed one by one by a paper feed roller 1 and conveyed to a registration roller 2 along a conveyance path P. On the other hand, an image of a developer (hereinafter referred to as toner), that is, a toner image is formed on the photosensitive drum 4 as an image carrier by the laser unit 3 and the developing device 5. The toner image formed on the photosensitive drum 4 is transferred onto the intermediate transfer belt 6. The developing device 5 has a developing unit for four colors of yellow, magenta, cyan, and black, and can form a toner image of each color on the photosensitive drum 4 by rotating in the direction of the arrow 5y. The four color toner images are superimposed and transferred. A transfer roller 7 is placed on a sheet conveyed at a timing by a pre-registration sensor (not shown) and the registration roller 2.
Transfers the toner image on the intermediate transfer belt 6, and the fixing device 8 fixes the toner image.

Thereafter, the sheet is conveyed by a first discharge roller 9 and a second discharge roller 10, and is discharged like a stacked sheet PE. FIG. 4 is a flowchart of processing in the image forming apparatus. When the image forming apparatus is started, step S
As shown at 401, the remaining amount of each of the cyan, magenta, yellow, and black toners is detected by a toner remaining amount detection unit (not shown) arranged near the developing device 5. Step S402
Then, based on the detected remaining amount, a control unit (not shown) of the image forming apparatus is left in a facility such as a toner cartridge (not shown) near the developing unit 5 for storing toner in the image forming apparatus. It is determined for all the toners whether the amount of the used toner is equal to or more than a predetermined amount necessary for image formation. Only when it is determined that the amount of the toner is equal to or more than the predetermined amount, the process proceeds to step S404, and the image forming state is set. Thereafter, when the image forming command signal is received in step S406,
Proceeding to step S407, an image forming process is performed. The image formation follows the procedure described above as an example. When the image formation is completed, the process returns to step S401 to detect the remaining amount of toner, and determines whether the next image can be formed.

If it is determined in step S408 that the remaining amount of at least one type of toner is equal to or less than a predetermined amount, the process advances to step S412 to display or inform the image forming apparatus that image formation is impossible. End processing such as notifying the user by means is performed, and the processing ends.

[0005] Such display or notification may be made when the toner cartridge is not mounted in the image forming apparatus or when the toner cartridge is not properly mounted, in addition to the case where the amount of remaining toner is insufficient. even if,
Image formation cannot be started unless these factors are removed.

[0006]

In such a conventional color image forming process, there are the following problems. In image formation, even if there is a means for displaying or informing the user that a certain amount of toner is less than a predetermined amount and the image cannot be formed, the image cannot be formed until the factor is removed. Even if one or more types of toner are insufficient but black toner is not insufficient, that is, even if a monochrome image can be formed, it is not possible.

Further, the conventional image forming apparatus has a display or notification means for notifying that it is almost time to refill the toner, such as replacing the toner cartridge, when the amount of remaining toner becomes low. In many cases, the user is provided with a period for preparing a toner for refilling before the toner cannot be formed. However, in the actual use state, this display or notification may not be regarded as important and may be ignored. In this case, the image forming apparatus cannot be used at all until the toner for refilling is arranged. It would be inconvenient to do so. Further, in an image forming apparatus capable of forming a color image, both color image formation and monochrome image formation are possible, but there is only one type of display or notification means indicating that image formation is possible. When it becomes impossible to form only one of the color and monochrome images, it does not have a means for displaying or notifying that the other image formation is possible. Because it is prohibited, it is difficult to say that convenience is provided for the user.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus having image forming means for forming a color image on a sheet.
The image forming apparatus further includes a unit for detecting a remaining amount of toner, and when at least one type of toner other than black toner is equal to or less than a predetermined amount, an image formation enabling only monochrome image formation, or When the remaining amount of toner is equal to or more than a predetermined amount, the image forming apparatus is in an image forming state in which a color image can be formed. As a result, even when the remaining amount of at least one type of toner other than the black toner becomes equal to or less than a predetermined amount, the apparatus can be used as a monochrome image forming apparatus until the toner is refilled by replacing a toner cartridge or the like. .

In order to solve the above-mentioned problems, a second invention according to the present application is directed to a method of forming a color image in the color image forming state of the image forming apparatus even when the remaining amount of the black toner is less than a predetermined amount. It is characterized in that a color image can be formed only by color toner without using it. As a result, even before refilling the black toner,
An image forming apparatus can be used.

In order to solve the above-mentioned problems, a third invention according to the present application is the image forming apparatus, further comprising means for displaying or notifying a user of two monochrome or color image forming states. It is characterized by the following. Accordingly, when the remaining amount of at least one type of toner is equal to or less than a predetermined amount, the user can know an image that can be formed in the image forming apparatus and can transmit an appropriate command signal to the image forming apparatus. The effects of the first invention and the second invention can be fully utilized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings. An image forming apparatus having the features shown in the present invention is the same as that shown in the conventional example as shown in FIG.

FIG. 1 shows a first embodiment of the present invention and shows a flow of processing in an image forming apparatus. When the image forming apparatus is started, the remaining amount of the cyan, magenta, yellow, and black toners is detected by the toner remaining amount detection unit as shown in step S101. In step S102, based on the detected remaining amount, the control unit of the image forming apparatus determines whether the remaining amount of toner is equal to or more than a predetermined amount necessary for image formation for all four color toners. If it is determined that the amount of toner is equal to or more than the predetermined amount for all four colors, step S10
Proceeding to No. 4, the image forming apparatus is ready to form a full-color image. Thereafter, when the image forming command signal is received in step S106, the process proceeds to step S107, and the image forming process is performed. When the image formation is completed, step S1 is performed again.
Returning to step 01, a process for detecting the remaining amount of toner is performed, and whether or not the next image can be formed is determined in the same flow as described above.

If it is determined in the color toner remaining amount determination step S102 that the remaining amount of at least one of the four toners is equal to or smaller than a predetermined amount, the flow advances to step S108 to control the image forming apparatus. Department
It is determined whether or not the remaining amount of the black toner, which is the minimum required for forming a monochrome image, is equal to or more than a predetermined amount. If it is determined that the remaining amount of black toner is equal to or more than the predetermined amount, step S1
In step 09, the image forming apparatus takes a state in which only a monochrome image can be formed. Thereafter, when a monochrome image forming command signal is received in step S110, the process proceeds to step S107, and a monochrome image is formed. Upon completion of the image formation, the process returns to step S101 to perform a process of detecting the remaining amount of toner, and determines whether or not the next image can be formed by the same flow as described above. If a color image forming command signal has been received in step S110, the process proceeds to step S111, in which the user is informed that the data format is incompatible, data is discarded, and the process returns to the command waiting state. Here, as to a method of determining whether the command signal is a monochrome image signal or a color image signal, for example, the head of the image forming command signal indicates whether the subsequent data is a monochrome image or a color image. There is a method in which a signal representing the instruction signal is added on the transmitting side of the command signal, and the signal is read to make a determination, or a method in which all the image data is read to determine whether or not data other than black is included is determined. .

Further, a step S108 for determining the remaining amount of black toner.
In step S112, the process proceeds to step S112 only when it is determined that the remaining amount of black toner is equal to or less than the predetermined amount, and after all processes such as notifying the user that image formation is not possible, all processes are terminated.

(Second Embodiment) An image forming apparatus having the features shown in the present invention is the same as that shown in the conventional example as shown in FIG. FIG. 2 shows a second embodiment of the present invention and is a flow of processing in the image forming apparatus.
As in the first embodiment, after starting the image forming apparatus, the process proceeds to step S2.
At 01, the remaining amount of toner is detected. Step S102
Then, based on the detected remaining amount, the control unit of the image forming apparatus
Cyan, magenta, minimum required for color image formation
It is determined whether the remaining amount of toner is equal to or greater than a predetermined amount for all three types of yellow toner. If it is determined that the remaining toner amounts of all three colors are equal to or more than the predetermined amount, the process proceeds to step S203, and the control unit determines whether the remaining black toner amount is equal to or more than the predetermined amount. If it is determined that the remaining amount of black toner is equal to or more than the predetermined amount, the process proceeds to step S204, and the image forming apparatus is in a state where a full-color image can be formed. If it is determined in step S203 that the remaining amount of the black toner is equal to or less than the predetermined amount, the process proceeds to step S205, and the image forming apparatus is in a state where an image can be formed using only three color toners other than the black toner. At this time, by expressing black with three color toners of cyan, magenta, and yellow, a color image can be formed using only three color toners other than black. Thereafter, when an image forming command signal is received in step S206, the process proceeds to step S207, and an image forming process is performed. When the image formation is completed, step S2 is performed again.
Returning to step 01, a process for detecting the remaining amount of toner is performed, and it is determined whether or not the next image can be formed by the same flow as above.

If it is determined in the color toner remaining amount determination step S202 that the remaining amount of at least one of the three toners is equal to or less than a predetermined amount, the process proceeds to step S108. The following processing flow is the same as in the first embodiment, and a description thereof will be omitted.

[0017]

As described above, the first embodiment according to the present application is described.
According to the invention, the color image forming apparatus has two types of printable states, a monochrome image formation possible state and a color image formation possible state, and the remaining amount of at least one type of toner other than the black toner is equal to or less than a predetermined amount, and In the case where only image formation is possible, the monochrome image formation is enabled when a monochrome image formation signal is received, so that the image forming apparatus is completely used until the toner is refilled by replacing the toner cartridge or the like. It is possible to improve the situation that you cannot do it.

According to the second aspect of the present invention, even when only the remaining amount of the black toner is equal to or less than a predetermined amount, black can be expressed by the color toner, and a color image can be formed. Further, similarly to the effect of the first aspect, it is possible to improve a situation in which the image forming apparatus cannot be used at all until the black toner is refilled.

Further, by providing a color image forming apparatus with a plurality of types of means for displaying or notifying a state in which an image can be formed, even when one or more types of toners are equal to or less than a predetermined amount, image formation is performed only with the remaining toners. If possible, it is possible to display or inform the user of the fact, and the user can know an image that can be formed in the image forming apparatus and transmit an appropriate command signal to the image forming apparatus. And the effect of the second invention can be fully utilized.

[Brief description of the drawings]

FIG. 1 is a processing flowchart of an image forming apparatus according to Embodiment 1 of the present invention;

FIG. 2 is a processing flowchart of an image forming apparatus according to Embodiment 2 of the present invention;

FIG. 3 is an example of a cross-sectional view of the image forming apparatus.

FIG. 4 is a processing flowchart in an example of a conventional color image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Registration roller 3 Laser unit 4 Photosensitive drum 5 Developing device 6 Intermediate transfer belt 7 Transfer roller 8 Fixing device 9 First paper discharge roller 10 Second paper discharge roller PS Sheet as a recording medium PE Loaded sheet L Image forming apparatus

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/46 H04N 1/46 C (72) Inventor Toshimitsu Iso 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc.

Claims (3)

[Claims] In an image forming apparatus having four types of developers of cyan, magenta, yellow, and black, an image forming state in which the remaining amount of one of the cyan, magenta, and yellow developers is equal to or less than a predetermined amount is determined. An image forming apparatus wherein only a monochrome image can be formed when a monochrome image signal is received. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus forms a color image without using a black developer even when the remaining amount of the black developer is equal to or less than a predetermined amount. Forming equipment. 3. The image forming apparatus according to claim 1, further comprising means for displaying or notifying whether a monochrome image can be formed or a color image can be formed.
Alternatively, the image forming apparatus according to claim 2.