JP2000075628A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance efficiency by eliminating a useless control operation by controlling an image forming operation according to the remaining quantity of toner. SOLUTION: It is judged whether the prescribed quantity of toner exists or not (12). When the residual quantity of toner is reduced to such an extent that concentration need not be controlled, it is warned that the toner does not exist (15) and operation is transferred to a standby state (14). Since the toner does not exist, the concentration is not controlled. When the toner sufficiently exists, the concentration is controlled (13) and the operation is transferred to the standby state (14).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer and a copying machine.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus, particularly a full-color printer or the like, an image density control means is used in order to maintain a stable image quality without a change over time.

For example, a patch is actually formed on an intermediate transfer member, and its density is measured to feed it back to image forming conditions.

[0004] The object of feedback is various such as high voltage bias, optical level, and halftone pattern.

When these feedbacks do not converge due to a shortage of developer (toner) or an abnormality in the main body sensor, a user interface for prompting the user to replace a developing part or repair the main body is used.

[0006]

However, in the case of the above-described prior art, the following problems have occurred.

[0007] Even in the case of a full-color printer, printing is often continued at a level at which stable image quality cannot be maintained.

This is because the replacement of the developing parts is costly for the user, and there is also a problem of environmental conservation.

In addition, in a maintenance-free printer, a new developing cartridge is used exclusively for printing that emphasizes image quality, and an old developing cartridge is used for printing tests and printing that does not emphasize image quality. There is also a device.

[0010] However, under the present circumstances, image quality-oriented control is always performed regardless of the intention of these users.

This not only impairs the user's convenience as described above, but also results in wasteful use of the developing material.

[0012] Further, since the time required for the density control is extra, the total response is also reduced.

Further, even when the density control is not necessary or meaningless, the developer is consumed, and extra time is required for the density control until printing is completed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to eliminate unnecessary control operations by performing image forming operation control according to the remaining amount of toner. An object of the present invention is to provide an image forming apparatus that achieves efficiency.

[0015]

According to the present invention, there is provided an image forming means for forming a toner image, a toner remaining amount detecting means for detecting a remaining amount of toner, A density control means for controlling an image density by adjusting a toner amount, in the image forming apparatus, whether or not to control the image density by the density control means based on a detection result by the toner remaining amount detection means; Is provided.

Therefore, it is possible to determine whether or not to control the image density according to the remaining amount of toner, so that unnecessary image density control can be eliminated.

When the toner remaining amount detecting means detects a remaining amount at a level at which the control of the image density by the density controlling means does not work effectively, the density control may not be performed.

A selection means may be provided for allowing a user to select whether or not to control the image density by the density control means based on the detection result by the toner remaining amount detection means.

The result of the detection of the remaining amount of toner by the toner remaining amount detecting means is not in the guaranteed range in which the control of the image density by the density control means works effectively, and is in a range in which the control can be effectively operated. In some cases, the selection means may allow the user to make a selection.

Preferably, the density control means performs control for feeding back to image forming conditions including at least an exposure amount and a developing bias based on the reflection density of the test image.

[0021]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) An image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram of a color laser beam printer (hereinafter abbreviated as LBP) according to a first embodiment of the present invention, around density control and toner remaining amount detection.

In FIG. 1, reference numeral 1 denotes a CP for controlling the LBP.
U, 2 an exposure unit, 3 a toner remaining amount detection unit, 4 a high voltage control unit such as a developing bias, charging and transfer bias, 5 a drum driving unit, 6 another driving unit such as a fixing device, and 7 a density control unit. Sensor 8 is an interface with the outside.

Since the LBP image forming process (image forming means) used in the present embodiment is a known technique, detailed description will be omitted, and density control and toner remaining amount detection will be described in detail.

In the density control in this embodiment, a solid image (test image) having an area where the reflection density can be read by the density sensor 7 is formed by the same process as image formation, and the reflection density is measured by the density sensor. 7 by reading.

The density read by the density sensor 7 is fed back to the image forming process conditions (exposure amount, developing bias, etc.) by the CPU 1 and is reflected in the control of the high-voltage controller 4 and the exposure unit 2.

In this embodiment, an intermediate transfer member is used as a place where a solid image is formed.

In the toner remaining amount detection in this embodiment, a window for transmitting transmitted light is provided in a box in which toner is stored, and the amount of transmitted light blocked by residual toner is detected by the remaining amount detecting unit 3. This is an optical detection method.

The density control (density control means) and the toner remaining amount detection method (toner remaining amount detection means) used in the present embodiment are well-known technologies as in the image forming process, and therefore, detailed description is omitted. This is also controlled by the CPU 1, and the density control and the toner remaining amount detection can be controlled independently.

Next, a judgment means for judging whether or not to control the image density will be described.

FIG. 2 shows a flow chart of the LBP initial processing in the present embodiment.

In the initial processing, the LBP is brought into a state in which an image can be formed by an instruction from the external interface 8 (standby state).

The initial processing is performed when the power of the LBP is turned on.
This is performed at the time of door closing after cartridge replacement or jam clearance, and at the time of wake-up returning from the sleep state.

When the initial processing is started (10), first, the remaining amount of toner of each color is detected (11).

Then, it is determined whether or not the amount of toner is a predetermined amount (an amount that does not require density control (or an amount that cannot be density controlled)) (12).

If the remaining amount of any of the toners has decreased to an amount that does not require density control, a warning indicating that there is no toner is displayed (15), and a transition is made to the standby state (1).
4).

At this time, since there is no toner, density control is not performed.

If there is sufficient toner, density control is performed (13), and a transition is made to the standby state (14).

FIG. 3 is a graph showing an error between the result of detection by the toner remaining amount detector 4 and the actual amount of remaining toner.

The limit amount at which the image quality can be maintained (guaranteed) by the density control is indicated by 21.

As shown in the figure, since there is an error between the result of detection of the remaining amount and the actual remaining amount, when it is determined that the result of the detection of the remaining amount in step 11 is smaller than the level of 22, the control is shifted to 15. And no density control is performed.

As described above, when it is determined that the remaining amount of toner is smaller than the limit at which the image quality can be maintained by the density control, the initial processing is quickly terminated by not performing the density control. It became possible.

As a result, the throughput in printing is improved.

Further, when the amount of remaining toner is small, unnecessary toner consumption by density control can be suppressed, and more printing can be performed.

As described above, by performing the image forming operation control in accordance with the remaining amount of toner, it is possible to eliminate unnecessary control operations and improve efficiency.

In the present embodiment, optical detection is performed as a method for detecting the remaining amount of toner. However, if the density control and the remaining amount of toner can be controlled independently by the CPU 1, other detection methods may be used. This is equally effective.

Regarding the density control, the present embodiment has the same effect other than the method of forming a patch on the intermediate transfer member as in the present embodiment when toner is actually consumed by the density control.

Further, in the present embodiment, the execution reference of the density control is set to any of power-on, door-close, and wake-up. Even in this case, the same effect can be obtained if the density control is not performed without the toner.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention. In the present embodiment,
When it is detected that the remaining toner is within a predetermined range,
This figure shows a case where the user can select whether or not to perform density control.

The configuration of the present embodiment has the same basic configuration as that of the above-described first embodiment, and therefore, the description will focus on the differences from the first embodiment.

In this embodiment, the user inputs an instruction via the external interface 8 shown in FIG. 1 as to whether or not to perform density control when there is no toner.

That is, although the image quality is basically not guaranteed even when the density control is performed between the levels indicated by 23 and 22 in FIG. 3, there is a possibility that a stable image is output by the density control. I have.

Therefore, in the present embodiment, a configuration (selecting means) is provided in which it is possible to select whether or not to perform density control in this range according to a user's instruction.

FIG. 4 shows a flow chart of the initial processing in the second embodiment.

The operation up to the remaining amount detection (31) is the same as in the first embodiment.

Next, if there is a color whose toner remaining amount is lower than the level 22 in FIG. 3, it is determined that the image quality cannot be assured, and the process proceeds to the warning display (35).

Then, it is checked whether the remaining amount of toner is higher than the level 23 in FIG. 3 (36).

If the remaining amount of toner is smaller than that, the level is determined to be unacceptable, and the process directly shifts to the standby state (34).

Here, when the remaining amount of toner is between 22 and 23, the possibility of stable image quality is also left.
Move the process to 7).

It should be noted that if a plurality of colors are in the toner-free state, even if one color has less toner than the level of 23, it is determined that the level is unacceptable.

At (37), it is checked whether or not there is an instruction from the user through the external interface 8 to perform density control.

If the user has instructed to perform density control (with no acceptable toner), (3.
The process is shifted to 3) to perform density control.

If not, a standby state is set.

As described above, by making it possible to select whether or not to perform density control within an allowable range according to a user's instruction, the possibility of outputting a stable image is further increased.

As a result, it is possible to improve the usability in a case where a user who requires a stable image quality and a user who requires a long toner life coexist.

In the present embodiment, the range shown in FIG. 3 is set as the allowable range. However, if the range shown in FIG. It is also possible to keep the image as stable as possible to the end.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention. In the present embodiment,
A configuration is shown in which the present invention is applied to a case where the basic configurations of density control and toner remaining amount detection described in the first embodiment are different.

The configuration of the present embodiment has the same basic configuration as that of the above-described first embodiment, and therefore the description will focus on the differences from the first embodiment.

In this embodiment, the configuration is such that the remaining toner amount can be independently detected prior to the density control.
Unless the image formation, that is, the density control or the printing operation is performed, the toner remaining amount cannot be detected.

This is because the inside of the box containing the toner is agitated by forming an image.

In this embodiment, an embodiment in which the present invention is applied to such a configuration will be described.

The detailed description of the toner remaining amount detecting means in this embodiment is omitted because it is a known technique.
The feature of this toner remaining amount detecting means is that it cannot be performed independently of the density control.

FIG. 5 is a flowchart showing the flow of processing relating to density control and toner remaining amount detection in the third embodiment.

When the power of the LBP is turned on, the processing (40)
start from.

In FIG. 5, processes irrelevant to the relationship between density control and toner remaining amount detection, such as I / O initialization, are omitted.

Then, the flag F for storing the state relating to the remaining amount of toner is set to false (41), and the process proceeds to (45).

When the door of the LBP is closed or in the case of wake-up, the processing starts from (42).

Then, before the process starting from (42), it is checked whether there is any evidence that the toner cartridge has been replaced (toner has been replenished) (43).

A known technique is used for the evidence detecting means of toner cartridge replacement, and detailed description in this embodiment is omitted.

If there is a possibility that the toner has been replenished, the flag F is reset in (44).

If there is no possibility of toner replenishment, the flag F is left as it is (moving to (45)).

The processing from (45) is common to power-on, door-close, and wake-up.

Check the flag F, and if F is true,
Assuming that the toner absence at the level where the density control should not be performed is detected, a toner absence warning is issued (46), the density control (47) is skipped, and the standby state (5
Move to 0).

When F is false, density control is performed, and at the same time, the absence of toner is checked (47).

If the absence of toner is detected, the flag F is set to true (49).

In the standby state (50), when image formation is started (51), the remaining amount of toner is detected at the same time, and when the absence of toner is detected, the flag F is set to true (53).

Note that, in FIG. 5, the toner-out warning output in the toner-out detection during image formation is omitted.

As described above, even when the absence of toner is detected along with the image formation, the toner absence information is stored and the density control is not performed, thereby improving the speed of image formation and consuming extra toner. It became possible to hold down.

[0090]

As described above, according to the present invention, it is possible to determine whether or not to control the image density according to the remaining amount of toner. Consumption can be suppressed, the processing speed can be improved, and efficiency can be improved.

When the toner remaining amount detecting means detects a remaining amount at a level at which the control of the image density by the density controlling means does not work effectively, the density control is not performed so that the wasteful image density Control can be eliminated.

If the selection means is provided, it is possible to cope with the intention of the user.

[Brief description of the drawings]

FIG. 1 is a block diagram of a configuration around a density control and a toner remaining amount detection of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of an initial process according to the first embodiment of the present invention.

FIG. 3 is a graph showing a relationship between a detection result of a toner remaining amount detection unit and an actual remaining amount of toner.

FIG. 4 is a flowchart of an initial process according to a second embodiment of the present invention.

FIG. 5 is a flowchart of an initial process according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 Exposure part 3 Toner residual amount detection part 4 High voltage control part 5 Drum drive part 6 Other drive parts 7 Density sensor 8 Interface

Claims (5)

[Claims] An image forming means for forming a toner image; a toner remaining amount detecting means for detecting a toner remaining amount; and a density controlling means for controlling an image density by adjusting a toner amount of an image to be formed. An image forming apparatus comprising: a determination unit configured to determine whether to control the image density by the density control unit based on a detection result by the remaining toner amount detection unit. 2. The apparatus according to claim 1, wherein said toner remaining amount detecting means does not perform density control when detecting a remaining amount at a level at which image density control by said density controlling means does not work effectively. Item 2. The image forming apparatus according to Item 1. 3. A selection means for allowing a user to select whether or not to control image density by said density control means based on a detection result by said toner remaining amount detection means. Or the image forming apparatus according to 2. 4. The result of detection of the remaining amount of toner by the remaining toner amount detection means is not within a guaranteed range in which the control of image density by the density control means works effectively, and there is a possibility that the control works effectively. 4. The method according to claim 3, wherein when the value is within the range, the user is caused to select by the selection unit.
An image forming apparatus according to claim 1. 5. The apparatus according to claim 1, wherein said density control means performs control to feed back to image forming conditions including at least an exposure amount and a developing bias based on the reflection density of the test image. An image forming apparatus according to any one of the above.