JPH08166713A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of preventing the occurrence of the absent state of a developer during the formation of an image. CONSTITUTION: When the image is inputted as an electric signal through an image input part 31 consisting of a CCD, etc., prescribed proper image processing is added in an image processing circuit 401 and a semiconductor laser element 32 is modulated/driven with image data after the processing is added, in a laser driving circuit 326. But, before the modulating/driving, the consumption of the developer is estimated by an estimating circuit 2, based on the image data and a system controller 1, estimates the amount of the developer in a developer container, after the image is formed with the image data with the developer consumption estimated by the estimating circuit 2 and a developer consumption history up to that time and when it is judged that a remaining amount is less than a fixed amount, the absence of the developer is displayed by an operating part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device used in a digital copying machine or the like for predicting the replenishment of a developer by a control signal obtained by arithmetically processing an image signal.

[0002]

2. Description of the Related Art In an apparatus for forming an image by using a developer such as a copying machine, it is necessary to appropriately supply the developer.
This is a necessary function for maintaining good image output. Particularly in color image formation, since the difference in tint of each color greatly affects the image quality, highly accurate developer replenishment is required. In that respect, the following method has been conventionally used as a method for controlling the supply of the developer from the developer storage container to the developing device.

First, there is a method in which the amount of toner is detected and the developer is replenished on the developing sleeve based on the difference in reflectance between the toner in the developer and the carrier in the near infrared region. Next, there is a method in which the toner image is actually developed on the photosensitive drum by toner, and the density of the portion is detected by an optical sensor to detect the toner amount in the developer and replenish the developer. .

There is also a method of supplying a developer in an amount proportional to the cumulative value of all or part of the image data in a digital image forming apparatus that handles an image as a digital amount, and further, the above two methods. A combination with the method is also proposed.

Further, regarding replenishment of the developer in the developer storage container, a piezoelectric sensor or the like is provided in the developer storage container as a detecting means, so that the developer can be stored in the developer storage container up to a certain amount. When the device detects that it is no longer used during image formation, the apparatus sends a message to the operator to replenish the developer after the completion of a series of image formation or before the next image formation, and prompts the developer replenishment by developing the developer. We are replenishing. This method is effective only when the number of image forming copies is not so large that it is possible to perform image formation while maintaining the image quality of a series of image formation with a fixed amount of the remaining amount even if the absence of the developer is detected. .

[0006]

However, in the color image forming apparatus, as an apparatus capable of forming a large number of images with higher productivity is developed, the apparatus continues to operate for a long time. However, there are the following problems.

For example, in an apparatus capable of forming 30 images on one side of an A4 size sheet per minute, automatic image formation on both sides of 10 sheets is possible.
When 100 sheets are printed, a little over one hour is required for the image forming operation, but it is unlikely that the operator is monitoring the image forming apparatus during such a long period of time, and the operator cannot form an image. It is expected that the device will be separated from the device at the start of the process and returned to the device after a lapse of time when the desired image formation is considered to be completed, and the output will be confirmed.

Therefore, if the apparatus is stopped during image formation for some reason, the operator eliminates the cause and then repeats image formation for a long time.
Moreover, in a color image forming apparatus, compared with a black and white image forming apparatus in which character images are frequently generated, an image in which the developer is placed on the entire image to be formed is generated more frequently, and the developer consumption is higher. However, the image formation may be performed in the state where the developer is absent.
This is also due to the fact that the color image forming apparatus requires developers of a plurality of colors, so that the capacity of the developer storage unit for each color is limited.

As described above, when a series of image formation is executed as it is while the absence of the developer is detected during the image formation,
There is a problem that the developer is completely lost in the developing device, and a large amount of image output having different colors and the like is output.

It is an object of the first invention of the present application to provide an image forming apparatus capable of solving the above-mentioned problems and preventing occurrence of a state of no developer during image formation.

In addition to the above-mentioned object, the second invention of the present application is an image forming apparatus capable of preventing a developer from being lost during image formation and outputting an image having a different tint. Is intended to provide.

[0012]

According to the first invention of the present application, the above object is to develop an image formed on the basis of input image data with a developer in a developing device, and In an image forming apparatus for outputting to an image forming apparatus, an estimating means for estimating a consumption amount of a developer based on an image data value of an input image, and a developer accommodating container to a developing device based on the consumption amount of the developer estimated by the estimating means. Replenishing means for replenishing the developer, a managing means for managing the history of the developer replenishing amount by the replenishing means, a developer consumption amount estimated by the estimating means before the development by the developing device and the management This is achieved by providing warning means for predicting the depletion of the developer based on the history of developer consumption by the means and issuing a warning of the replenishment of the developer to the developer accommodating container.

According to the second invention of the present application,
The above object is achieved by the warning means in the first invention, wherein the warning means is set to stop the image forming operation when the developer is predicted to be exhausted based on the developer consumption history and the estimated developer consumption amount. To be done.

[0014]

According to the first invention of the present application, the developer consumption amount is estimated based on the image data value by the estimating means before the development by the developing device is performed, and the estimated developer is estimated by the warning means. When it is predicted that the developer in the developer container will be depleted based on the consumption amount and the history of developer consumption by the management means, a warning is issued to replenish the developer container. Therefore, even when a large amount of images that consume a large amount of developer are formed, it is possible to predict the depletion of the developer before the developing operation,
Prevents the occurrence of no developer during image formation.

According to the second invention of the present application,
In the first aspect of the invention, the warning means stops the image forming operation when it predicts that the developer will be exhausted based on the developer consumption history and the estimated developer consumption amount. Images with different tastes are not output.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. The apparatus of this embodiment is a digital color image forming apparatus, and is composed of a reader unit 301 and a printer unit 302, as shown in FIG.

In the reader unit 301, the document table 31
0 and the document pressure plate 311 are placed on the lamp 31
When scanning is performed in the direction of arrow V while irradiating with 2, the reflected light image from the document passes through the mirror group 313 and the lens 314 and is RG.
An image is formed on the CCD 315 on which the B3 color filter is applied,
The CCD 315 photoelectrically converts signals of RGB colors.

The image signal which has become an electric signal is processed by the image processing unit 4.
At 01, the following processing is performed according to the flow shown in FIG. The signal from the CCD 315 is the A / D & S / H section 41.
At 0, conversion into digital data is performed, and the shading correction unit 411 and the input masking unit 412 correct the image data. Magnification processing unit 413 during the magnification operation
Scale with. Next, in the LOG converter 414, RGB
Data is converted into CMY data, and the companding unit 415 for compressing, storing, and expanding the image data enters. The stored image data is read in synchronism with each color of the printer, which will be described later, and masked by the masking / UCR unit 416, and then the γ correction unit 417 and the edge enhancement unit 418.
CMYK output image data is created by the printer unit 3
Is sent to 02.

In the printer unit 302, the laser driving circuit 326 synchronizes each color, and the reader unit 30
The laser beams from the laser elements 321 to 324 which are driven independently of magenta (M), cyan (C), yellow (Y), and black (K) according to the image data from the photosensitive drum 340M to the photosensitive drum 340M.
Scan on 340K.

In the image forming section 331M, since the photosensitive drum 340M that is exposed to the laser beam is charged to a desired potential by the primary charger 344M, an electrostatic latent image is formed on the photosensitive drum 340M by the exposure. The formed electrostatic latent image is developed as a toner image by the developing sleeve 342M in the developing device 341M to which a developing bias is applied, and is conveyed to a transfer portion facing the transfer charger 348M.

Similarly, each of the image forming units 331C to 331C.
At 1K, a toner image of each color is formed and conveyed to each transfer section.

On the other hand, the image forming medium 11 such as paper is fed and conveyed from the sheet feeding devices 351, 352, the re-feeding device 350, or the manual sheet feeding device 353, and is fed onto the transfer belt 354. Then, each of the photosensitive drums 3
The toner images formed on 40M to 340K are sequentially transferred to the image forming medium 11 by the transfer belt 354.
Are transferred by the transfer chargers 348M to 348K,
Images of magenta, cyan, yellow, and black are overlaid to form a color image corresponding to the original.

The photosensitive drums 340M to 340 after transfer
The surface of 40K is cleaned by cleaners 345M to 345K, and further, auxiliary charging is performed by the auxiliary chargers 346M to 346K so that good charging can be obtained in the primary chargers 344M to 344K, and then the pre-exposure lamp 347M. By ~ 347K, the residual charge is erased. Then, the image forming medium P to which the color image as described above is transferred passes through the pre-fixing conveyance guide 355, and the fixing device 35.
6, the toner image is heated and fixed on the image forming medium P by the fixing device 356, and the sheet is discharged.

In the case of carrying out the back surface paper ejection for reversing and ejecting the image surface, the recording medium is conveyed to the reversal conveyance path 357, reversed in the reversal conveyance path 357, and then ejected. Further, in the mode in which double-sided image formation is performed, the fixed image forming medium 11 is fed from the reverse conveyance path 357 to the re-feeding conveyance path 3
58, and is fed to the re-feeding device 350.
It is arranged as a medium for performing image formation on the first side. .

Further, in the above apparatus, the developing sleeve 342
The toner on M to 342K is the developer concentration sensor 343M.
To 343K, the developer density is detected based on the reflected light amount, and the toner images formed on the photosensitive drums 340M to 340K are detected by the development density sensors 349M to 349K.

Next, the developer replenishing system in this apparatus will be described with reference to the block diagram of FIG.

An image is input as an electric signal through an image input unit 31 composed of a CCD 315 and the like, and in an image processing circuit 401, A / D conversion, shading correction,
Image processing suitable for image formation such as Log conversion, UCR processing, and γ correction is added. In the laser drive circuit 326, the semiconductor laser element 32 (laser elements 321 to 324) is based on the image data subjected to these processes.
Drive modulation. By scanning and exposing the output light of the semiconductor laser element 32 on the photosensitive drum 340 (340M to 340K), a latent image having a charge distribution corresponding to the input image data is formed on the photosensitive drum 340. The latent image is developed by the developer in the developing device 341 (341M to 341K) and transferred to the image forming medium 11, so that the developer is consumed. The estimation circuit 2, which is an estimation means, estimates the consumption amount of the developer from the same image data as that used for image formation.

By controlling the developer replenishing circuit 5 for driving the developer replenishing device 6 based on the output from the estimation circuit 2 or the like, the developer 9 in the developer accommodating container 7 is replenished to the developing device 341. In addition, the developer sensor 8 in the developer storage container 7
Is a system controller 1 which detects that the developer has run out to a certain amount in the developer storage container and is a warning means.
It is possible to output to the operator and indicate to the operator that there is no developer.

FIG. 2 shows a detailed circuit of the estimation circuit 2. Here, since it is considered that the developer consumption amount is roughly proportional to the integrated value of the image data, a circuit for integrating the image data values in one image will be considered as the estimation circuit.

Data is image data, and is an 8-bit signal in this embodiment. This Data is the AND circuit 2
According to 07, an 8-bit flip-flop (hereinafter referred to as FF) while the main scanning image effective section signal Henable and the sub-scanning image effective section signal Venable are both H
Input) to the A terminal of the 8-bit adder 202, and the adder 20 via the 8-bit FF 203.
The image data of one pixel before input to the B terminal 2 of 2 is added in synchronization with the pixel clock. The output Y = A + B
Is input to the FF 203 at any time, and the carry C is counted by the 8-bit counter 205 via the AND circuit 204. Then, a signal indicating that one image is finished is Ve
DFF208, NOR20 from the fall of the enable
The count value 9 is generated, and the count result is latched by the 8-bit D-latch 206 by the signal to obtain the integrated value c of the image data of one image.

The above Vsync *, Venable, H
An outline of the timing of enable, Data, and c is shown in FIG.
Shown in The clock to each FF and counter is VCLK which is a synchronizing signal of the image signal.

The system controller 1 reads out the latched data and applies a predetermined calculation to the integrated image data, whereby the developer consumption amount can be estimated based on the image data value.

Replenishment driving is performed based on the estimated developer consumption data and the output result from the developer concentration detection sensor 343 in the developing device 341 or the output result from the development concentration sensor 349 on the photosensitive drum 340. By driving the circuit 5 for a time t proportional to the replenishment amount, it is possible to replenish the developer properly.

Next, the flowchart of the developer replenishment control will be described with reference to FIG. When the copy start is accepted by the input from the operation unit 10 (S101), the set number N
Then, the copy sequence is started (S102). And
The image data is read, and the video count value c for the image is calculated by the circuit shown in FIG. 2 (S1).
03). Then, from the relation constant t ₀ between the count value c and the toner supply, the estimated consumption amount C by a series of image formation C = t ₀ * c
* N and the estimated remaining amount T _Z = T ₀ −T _S which is a value obtained by subtracting the toner consumption cumulative value T _S from the initial toner amount T ₀
Is calculated (S104). Then, the estimated consumption amount C and the estimated remaining amount T _Z are compared (S105), and if the estimated consumption amount C exceeds the estimated remaining amount, the sequence without toner (S11).
Go to 0). On the other hand, if the estimated consumption amount C is less than the estimated remaining amount, after the toner amount is checked by the sensor (S1
06), the copying operation is performed (S107), the toner replenishment drive according to the video count value is performed for the time t, and the toner consumption cumulative value T _S is calculated from the relation constant t ₁ between the drive time t and the toner replenishment T _S = It is calculated as T _S + t ₁ * t (S10
8). Here, it is assumed that the toner consumption cumulative value T _S is stored in an area to be backed up in the memory of the system. This operation is performed up to the set number N (S109), and a series of copy operations is completed. When it is estimated or detected that there is no toner in S105 or S106, the copy operation is stopped, and a message prompting the operator to replenish toner is displayed from the operation unit (S110). Then, when the toner is replenished, the toner consumption cumulative value T _S is cleared (S111), and the sequence ends. By performing this series of operations for each recording color, toner replenishment control by toner consumption estimation based on the video count becomes possible.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment, the estimated toner consumption amount with respect to the video count value c is calculated by a simple calculation by the CPU. However, when more accurate replenishment is considered,
The hardware calculation is effective by recording and reading the relationship of the estimated toner consumption amount with respect to the video count value which is different for each recording line number (200 lines / 400 lines). A detailed block diagram of the estimation circuit is shown in FIG. D
ata is the line number switching signal Se in the selector 702.
The data is divided into 200-line data 200data and 400-line data 400data by l, and each is input to the count circuit 701. The 200-line data video count value c200 is a table 703 in which 200-line toner consumption conversion values are recorded, and the 400-line data video count value c400 is a 400-line toner consumption conversion value table 704. And toner conversion values c2 and c4 are output. And
As shown in the flowchart S204 shown in FIG. 8, by calculating C = (c2 + c4) * N as the estimated consumption amount C, it is possible to calculate the toner consumption amount with higher accuracy.

[0038]

According to the first invention of the present application, the developer consumption amount is estimated based on the image data value by the estimating means before the development by the developing device is performed, and the estimation is performed by the warning means. If it is predicted that the developer in the developer storage container will be depleted based on the developer consumption amount and the history of developer consumption by the management means, a warning is issued to replenish the developer storage container, so image formation is performed. It is possible to prevent the state of no developer inside.

According to the second invention of the present application,
In the first aspect of the invention, when the warning unit predicts that the developer will be exhausted based on the developer consumption history and the estimated developer consumption amount, the image forming operation is stopped. It is possible to prevent a large amount of different images from being output.

[Brief description of drawings]

FIG. 1 is a block diagram of a developer replenishing system according to a first embodiment of the present invention.

2 is a detailed block diagram of an estimation circuit in the apparatus of FIG.

FIG. 3 is a configuration diagram of a digital copying machine according to the first embodiment of the present invention.

FIG. 4 is a block diagram of image data processing according to the first embodiment of the present invention.

FIG. 5 is a timing schematic diagram of image data control signals in the first embodiment of the present invention.

FIG. 6 is a flowchart of a developer replenishment control according to the first embodiment of this invention.

FIG. 7 is a block diagram of image data processing according to the second embodiment of the present invention.

FIG. 8 is a flowchart of developer replenishment control according to a second embodiment of the present invention.

[Explanation of symbols]

 1 System Controller (Management Means, Warning Means) 2 Estimating Circuit (Estimating Means) 5 Developer Replenishing Circuit (Replenishing Means) 6 Developer Replenishing Device (Replenishing Means) 7 Developer Storage Container 9 Developer 11 Image Forming Media 341M, 341C , 341Y, 341K developing device

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Claims (2)

[Claims] 1. An image forming apparatus for developing an image formed on the basis of input image data with a developer in a developing device and outputting the image on an image forming medium. Estimating means for estimating the consumption amount, replenishing means for replenishing the developer from the developer storage container to the developing device based on the consumption amount of the developer estimated by the estimating means, and a history of the developer replenishing amount by the replenishing means. Managing means for managing the developer, predicting the depletion of the developer on the basis of the developer consumption amount estimated by the estimating means before the development by the developing device and the developer consumption history by the managing means. An image forming apparatus comprising: a warning unit that issues a warning that a developer is replenished in a storage container. 2. The warning means is set to stop the image forming operation when the developer is predicted to be exhausted based on the developer consumption history and the estimated developer consumption amount. Image forming apparatus.