JPS61185762A - Image recorder - Google Patents

Abstract

PURPOSE:To grasp accurately the remainder of a toner to replace a process cartridge at an optimum time by correcting exposure time information in accordance with the variance of toner consumption and generating a replacement signal on a basis of the correction time accumulated value. CONSTITUTION:A counter 3 is started by a modulator 1 to count clock pulses, and the exposure time of a photosensitive drum 101 is determined. This calculated value is corrected in accordance with the variance of toner consumption by a controller 6 which controls the laser light intensity from a laser 2 which is a factor of the variance of toner consumption. The correction counted value is accumulated, and the total of the corrected exposure time is stored in a memory 4; and when stored contents reach a prescribed value, the replacement signal is outputted through a comparator 5 and the controller 6, and the replacement time is displayed on a display means 7. Thus, the toner consumption is measured accurately to grasp the toner remainder accurately, and a process cartridge 112 where the drum 101, a primary charger 104, a developing device 106, etc. are built into one body is replaced at the optimum time. The similar operation is possible when the non-exposure time is utilized.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention has a process cartridge incorporating an image forming means, and scans an image carrier with light modulated in accordance with an image signal to form a latent image. The present invention relates to an image recording apparatus such as a laser beam printer that forms a visible image by attaching a developer to the latent image.

(Prior Art) FIG. 6 shows a schematic configuration diagram of a toshite laser beam printer, which is an example of the image recording device as described above. In FIG. Photosensitive drum, 104 is photosensitive drum 101
This is a primary charger that uniformly charges the top. A laser beam 105 (oscillated from the semiconductor laser 2) modulated in accordance with an image signal is scanned by a scanner 114 such as a rotating polygon mirror or a Gal-9 mirror, and is scanned onto the photosensitive drum 1.
01 is scanned and exposed to form an electrostatic latent image. A developing device 106 serves as an image forming means for visualizing an electrostatic latent image using toner, and is prefilled with a predetermined amount of toner. 10
A transfer charger 7 transfers a toner image onto a transfer paper (not shown) introduced from a transfer paper guide 108.

A cleaner 109 cleans untransferred toner remaining on the photosensitive drum 101 and stores the cleaned toner.

In such an apparatus, the photosensitive drum 101 and the developing device 106, cleaner 109, etc. around the photosensitive drum 101 are worn out and become dirty with toner, etc., so they must be inspected periodically and worn parts replaced. It requires cleaning and is not easy to maintain.

Therefore, together with the photosensitive drum 101, the primary charger 104, the developer 106, the cleaner 109, etc. are assembled into a housing 111 and integrated into a process cartridge 112.The process cartridge 112 is made disposable, thereby improving the maintainability. There is. Incidentally, the process cartridge 112 is supported and guided by a guide rail 113 fixed within the main body of the image recording apparatus, and is attached to and removed from the main body.

Such a process cartridge 112 measures, for example, the number of rotations of a photosensitive drum, and when this measured value reaches a predetermined value, it is determined that the toner filled in the developing device is used up and is replaced.

That is, when the remaining amount of toner becomes low, a warning light is emitted to indicate to the user that it is time to replace the process cartridge, and to prompt the user to prepare a new cartridge.

(Problem to be Solved by the Invention) However, in the case of such a conventional example, since the developing device is disposable, it can be used until the toner is almost exhausted. However, it is difficult to accurately detect such a low toner state. was difficult. Therefore, even if the toner light came on, it was not possible to determine how much toner could be used before it ran out, and the cartridge was replaced even though it could still be used9. The problem was that it was no longer possible to do so, and it was inefficient.

Therefore, we focused on the conventional method of attaching toner to the exposed portion of the laser beam on the photosensitive drum 101 to visualize it.
A device has been proposed that detects toner consumption by counting the number of laser beams.
3). However, toner consumption does not only depend on the number of dots; for example, the amount of toner consumed depends on the laser power.
It is affected by changes in the potential of the 01 surface and other factors such as the developing bias, and it is not possible to accurately determine the amount of toner remaining just by counting the number of dots. There was a problem that it could not be displayed.

The present invention has been made to solve the problems of the prior art, and its purpose is to accurately measure the amount of toner consumed, and (9) accurately grasp the remaining amount of toner. An object of the present invention is to provide an image recording device that displays an appropriate time to replace a process cartridge.

(Means for Solving the Problems) Therefore, in order to achieve the above object, the image recording device according to the present invention has the following advantages: a storage means for adding and storing time information corresponding to one of the two; and a storage means for comparing the time information stored in the storage means with a predetermined level set in advance, and a scale of the time information stored in the storage means is set in advance. and a correction means for detecting factors that change the amount of toner consumption and correcting the time information stored in the storage means. There is.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows an image recording apparatus according to an embodiment of the present invention. In this embodiment, the image recording apparatus is applied to a radar beam printer similar to the image recording apparatus shown in FIG. 6, and the same members as those in the apparatus shown in FIG. It is.

In the figure, reference numeral 1 denotes a modulator that modulates an image signal fv input from a computer (not shown) or the like to a radar input terminal, and turns the laser on and off in response to the image signal fv. A multilevel signal can be used as the image signal. That is, for high-density portions of the image, the light emission time corresponding to one pixel of the radar is lengthened, and for intermediate-density portions of the image, the light emission time corresponding to one pixel of the radar is shortened.

2 is a laser that is connected to the modulator 1 and emits light according to the modulated signal; 3 is a photosensitive drum that is connected to the modulator 1 and represents the output time from the modulator 1 to the laser 2; that is, the photosensitive drum for the laser beam output from the laser 2; This is a counter that measures time information corresponding to the exposure time to 101. That is, a clock pulse generating means 3' such as a crystal oscillator is connected to the counter 3, and measures the number of clock pulses received during the duration of the laser emission signal.

Furthermore, 4 is a memory connected to the counter 3 and serving as a storage means for sequentially adding and storing the output from the counter 3;
The memory 4 is connected to a comparator 5 as comparison means. ConzJ? The controller 5 is connected to a controller 6 as a correction means.

A predetermined level set in advance by the controller 6 corresponding to a predetermined consumption amount of toner is compared with time information corresponding to the total exposure time of the laser beam stored in the memory 4, and the time information is stored in the memory 4. When the exposure time of the laser beam becomes longer, a signal is input to the controller 6, and the controller 6 outputs a process cartridge 112 replacement signal Su. This exchange signal Su drives the display means 7 such as visible means such as a light emitting element LED and sound generating means. When the controller 6 and the memory 4 are connected and a signal 8 indicating that the user has replaced the cartridge is input, a reset signal R8T is input from the controller 6 to the memory 4 and the exposure time stored in the memory 4 is set to O. It is supposed to be returned.

Furthermore, the laser 2 and the controller 6 are connected, and the controller 6 is also adapted to make the output level of the laser 2 variable. The toner consumption value also changes depending on the laser output. That is, the higher the emission output of the laser 2, the greater the toner consumption, and therefore the shorter the life of the process cartridge 112. This relationship is shown in FIG. By obtaining a characteristic curve as shown in FIG. 82 in this way, it is possible to correct the amount added from the counter 3 to the memory 4. Controller 6 is laser 2
While changing the output of counter 3 to memory 4
Change the amount added to. When the characteristics of the laser light amount and the toner consumption amount are given in FIG. 2, specifically, when the laser output is 5 mW and the amount added from the counter 3 to the memory 4 per unit light emission time of the laser is 1, 4.0m
For W, 0.82.6 mW is corrected to add 1.08. Furthermore, the slope of the straight line in FIG. 2 may be changed depending on the type of device and toner, and it does not necessarily have to be a straight line, but may be a curve like B.

The amount of toner consumed also changes depending on the voltage applied to the roller 106' that carries and conveys the toner of the developing device 106 and supplies it to the photosensitive drum 101, that is, the developing via 2. It is well known that changing the developing bias changes the image density, but the amount of addition may be changed depending on the developing bias level. For example, as shown by straight line A in Figure 3, when the developing bias level is 1 and the image density is at a high level (negative in the figure), the amount added to the memory 4 is set to 1.5. . ), the addition amount is set to 1 for the normal concentration level, and when using a low concentration level (for pressure in the figure), the addition amount is set to 0.5 (A in the figure).
t). By changing the amount added to the memory 4 according to the developing bias level in this way, it is possible to more accurately grasp the toner consumption amount.

Furthermore, it goes without saying that the slope may be changed to a straight line B depending on the type of device or toner, and it does not necessarily have to be a straight line depending on the development characteristics.

The rest of the configuration is substantially the same as the device shown in FIG.

Next, the operation of this embodiment will be explained. An image input signal fv is modulated by a modulator 1 and input to a laser 2.

The laser 2 emits light (or attenuates or extinguishes light) in response to the image signal fv. At the same time, the counter 3 measures the output signal of the laser 2 from the modulator 1 and adds the light emission time of the laser 2 to the memory 4 starting from 0ρ.

The photosensitive drum 101 is scanned by a laser beam outputted in large numbers by V-f-2, and an electrostatic latent image is formed on a different surface of the photosensitive drum 101. During the developing process, toner may adhere to the latent image. A visual image is formed.

The radar beam printer used in the present invention employs a so-called reversal development method in which toner is attached to the portion of the photosensitive drum 101 irradiated with laser light (therefore, the toner is transferred to the photosensitive drum 104 by the primary charger 104). The amount of toner consumed is proportional to the emission time of the laser 20, and the amount of toner consumed increases as the exposure time of the laser 2 increases. When the total exposure time stored in the memory 4 exceeds a preset level corresponding to a predetermined amount of toner consumption, the controller 5
A replacement signal for the process cartridge 112 is output from.

Further, during development, the amount of toner consumed differs slightly between a line image and a peta black image for the same radar emission time. FIG. 4 shows toner consumption in the case of a line image (straight line A in the figure) and in the case of a solid black image (straight line B in the figure). As can be seen from the figure, line images are more affected by edge effect development, so toner consumption is generally higher. Therefore, the timing of issuing the toner out warning signal is determined by the amount of toner consumed by the line image. In other words, by issuing a warning signal at the 0 point of the straight line A shown in FIG. 4, it is possible to represent other images containing peta black.

Next, FIG. 5 shows a second embodiment of the present invention, and the same components as the first embodiment are designated by the same reference numerals. , has a counter 9 for counting the number of prints, and a memory 10 for storing the number of prints counted by the counter 9 is connected to the counter 9. Furthermore, a comparator 11 is connected to the counter 9, and when the value of the counter 9 matches the value of the comparator 11, the controller 6 outputs a stop signal (5TOP) to stop the image recording apparatus.

Counter 9 is reset at the same time as counter 3. The number of sheets that can be printed after the toner out notice is approximately 100 sheets, and the maximum amount of toner consumption per sheet that changes depending on the printing ratio is Xf, which is the limit of the remaining amount of toner in the developing device 106 without causing white spots. When is y2, is the amount of toner remaining in the developing device 106 (100x+y)? It is sufficient to issue an out-of-toner warning signal immediately before the toner out warning signal is reached, and to stop printing after 100 sheets have been printed.

Although a laser beam printer has been described in this embodiment, the exposure means may be a light emitting diode LED array, an optical fiber tube OFT, etc. other than a laser, and an electrophotographic device that has an image input signal and uses toner. If so, it is applicable.

Furthermore, in this embodiment, although the description has been made regarding the case where the image is developed by the reversal development method, the portion to which the toner is applied and visualized, such as characters or lines, is the non-exposed area, and the white background is 27.
This is also applicable to the case where 2271 parts are exposed with a light source such as a radar. In other words, similar control becomes possible by measuring the non-exposure time when the laser is turned off.

In addition, in the above embodiment, the length of the lighting time or the length of the lighting time of the light source was measured using a clock pulse.
24363, the number of dots in an image, that is, the number of times the light source emits or goes out, can be measured and used as the on-time or off-time.

However, there is some variation in the light emission or extinguishing time for one dot of the light source, depending on the individual light source, and if the υ light source is driven by a multilevel signal as described above, the lighting or extinguishing time of one dot can be Since it differs depending on the density, in such a case, the former is preferable because the amount of toner consumption can be detected more accurately.

(Effects of the Invention) The present invention has the above configuration and operation, and utilizes the fact that toner consumption is proportional to the exposure time or non-exposure time of the light source to the image bearing member. The amount of toner consumed can be accurately detected by measuring the amount of toner consumed and correcting the stored time information for fluctuation factors in the amount of toner consumed. The advantage is that there is no waste of having to replace the process cartridge first, and the process cartridge can be replaced at an appropriate time.

[Brief explanation of the drawing]

1 is a schematic configuration diagram of an image recording apparatus according to a first embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the amount of laser light and toner consumption of the apparatus of FIG. 1, and FIG. FIG. 4 is a diagram showing the relationship between the developing bias of the device and the amount added to the counter. FIG. 4 is a diagram showing the relationship between the laser emission time and toner consumption amount of the device in FIG.
FIG. 5 is a control block diagram of a second embodiment of the present invention, and FIG. 6 is a schematic configuration diagram of a conventional image recording apparatus. Explanation of symbols 51...Modulator 2...Laser 3...
・Counter 4...Memory (storage means) 5・
... Ko, N Valley 9 6... Controller (
Correction means) 101... Photosensitive drum (image forming means) 11
2...Process cartridge patent applicant Canon Co., Ltd. Figure 2 Figure 3! Figure 4

Claims (4)

[Claims] (1) It has a process cartridge incorporating an image forming means, which exposes an image carrier with light modulated in accordance with an image signal to form a latent image, and makes the latent image visible by the image forming means. In an image recording device for forming a visual image, a storage means for adding and storing time information corresponding to either an exposure time or a non-exposure time corresponding to an image signal of the light to the image carrier, and the storage means Comparing means for comparing the time information stored in the storage means with a predetermined level set in advance, and outputting a signal for replacing the process cartridge when the total time information stored in the storage means exceeds a predetermined level set in advance. and a correction means for detecting a factor that changes the amount of toner consumption and correcting the time information stored in the storage means. (2) The image recording apparatus according to claim 1, wherein the process cartridge replacement signal is a signal indicating a substantial replacement. (3) The image recording apparatus according to claim 1, wherein the process cartridge replacement signal is a signal indicating advance notice of replacement. (4) The replacement signal for the process cartridge is a display indicating advance notice of replacement, and the process cartridge has a stop means for placing the process cartridge in a non-operating state after a certain number of cartridges have elapsed after the replacement signal is generated. Image recording device.