JPH0922226A - Residual toner quantity detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect the residual toner quantity in a toner container, in an image forming device such as a laser beam printer of digital system. SOLUTION: By an AND gate 101, the AND of printing data output clock and the printing dot data are obtained, and the number of output signals is counted by a count part 102. At this time, the counted number and the cumulative number stored by a memory 103 are added by an adder 104. This added number becomes equal to the number of dots of an electrostatic latent image formed on a photoreceptor drum surface as set of the dots. By obtaining the product of the dot number and the toner quantity stuck on per one dot, total amount of the toner consumed from the toner container inside by sticking to the electrostatic latent image can be correctly computed, by a processor. Thus, the extent of consumption of the toner, and more the residual amount of the toner in the toner container can be correctly computed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner remaining amount detecting device mounted on an image forming apparatus such as a digital copying machine, a laser beam printer, or a facsimile which forms an image using toner.

[0002]

2. Description of the Related Art Conventionally, in a digital type image forming apparatus for forming an image using toner, such as a copying machine, a laser beam printer, a facsimile, etc., it is consumed as the number of image formed sheets (the number of copies) increases. It is known to use a magnetic sensor to detect the remaining amount of toner. In this system, the magnetism of the toner contained in the toner container is detected by a magnetic sensor, and the remaining amount of toner is detected depending on whether the detected value is larger or smaller than a predetermined value.

In addition to the above, there is one using an optical sensor. In this device, a light emitting portion and a light receiving portion are arranged horizontally with a toner storage container interposed therebetween, and it is checked whether or not the light receiving portion receives the light generated from the light emitting portion. When the toner in the toner storage container blocks the optical path and no light is received, "with toner" is detected, and when light is received, "no toner" is detected.

[0004]

However, in both of the above-mentioned magnetic sensors and optical sensors, the amount of toner remaining in the toner container is simply below a predetermined value, that is, the amount of toner remaining. Since it is detected that the amount is small, there is a problem that it is not possible to know how many more images can be formed when the image formation is continued after the detection.

That is, even when "no toner" is detected, some toner remains in the developing container, and therefore, it is not possible to immediately form an image, but several images can be formed. is there. Then, after that, it was only known that the image was not formed due to the toner shortage and the toner was used up for the first time.

Therefore, it is an object of the present invention to provide a toner remaining amount detecting device capable of accurately grasping the remaining amount of toner.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is applied to an electrostatic latent image formed on an image carrier as a set of dots based on print dot data. In a toner remaining amount detecting device for detecting a remaining amount of toner in a developing container to be consumed, a logical product forming section for taking a logical product of a print data output clock and the print dot data, and an output from the logical product forming section A counter for counting the number of output signals to be output, a memory for sequentially updating and storing the count, a count for output from the counter and a count for output from the memory, and the addition Based on the adder that stores the calculated count number in the memory as the cumulative count number, the cumulative count number output from the adder, and the toner amount attached per dot. In addition, the amount of consumed toner that is attached to the electrostatic latent image and consumed is calculated, and the remaining amount of toner in the developing container is detected from the consumed toner amount and the amount of toner initially stored in the toner storage container. And a processing device.

Further, a toner mode setting means for selecting the presence / absence of toner saving setting, and the output signal from the logical product forming section is divided based on the output of the toner mode setting means, and the output signal after the division is A frequency dividing device for inputting to the counter unit may be provided.

[Operation] Based on the above configuration, the cumulative count number output from the adder corresponds to the cumulative number of dots forming the electrostatic latent image. Therefore, the total amount of toner consumed from the toner container can be accurately calculated by calculating the product of the cumulative count number (cumulative number of dots) and the amount of toner attached per dot by the processing device. You can

Therefore, if the total amount of toner put in the toner container is known in advance, the remaining amount of toner in the toner container can be accurately detected.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> A toner remaining amount detecting device according to the present invention is
It can be mounted on an image forming apparatus such as a digital copying machine, a laser beam printer, or a facsimile. In the following description, a case where the toner remaining amount detecting device is mounted on a laser beam printer and an image is formed by reversal development will be described as an example.

The laser beam printer includes a drum-shaped photosensitive member (photosensitive drum) rotatably supported.
A primary charging device, an exposure device, a developing device, a transfer charging device, a cleaner and the like are arranged around the photosensitive drum in order along the rotation direction thereof. Further, a fixing device is arranged on the downstream side of the photosensitive drum in the transport direction of the transfer material, which is the transfer destination of the toner image.

In the laser beam printer constructed as described above, first, the surface of the photosensitive drum is uniformly charged to a predetermined negative voltage by the primary charger.

An electrostatic latent image is formed on the surface of the photosensitive drum after charging by the exposure device. The exposure device generates a laser beam by a laser oscillator, and the laser beam is generated by a lens,
It is guided to the photosensitive drum via a polygon mirror or the like. The laser light guided to the photosensitive drum irradiates the surface thereof as elliptical dots. The dots move on the surface of the photosensitive drum in the generatrix direction for main scanning by the rotation of the polygon mirror, and move in the circumferential direction for sub-scanning by the rotation of the photosensitive drum. At this time, by controlling the on / off of the laser light, the negative charge in the bright portion irradiated with the laser light is removed to form an electrostatic latent image. That is, the electrostatic latent image is formed as a set of dots by the main scanning and the sub scanning of the laser light generated based on the print dot data.

Next, the electrostatic latent image is developed as a toner image by a developing device to which the charged toner contained in the developing container is attached. Here, the amount of toner adhered to the latent image corresponding to one dot of the laser light described above is substantially constant, and therefore, the toner consumption amount is proportional to the number of dots forming the electrostatic latent image. become. That is, if the amount of toner adhered per dot of the latent image is w and the number of dots per sheet of transfer material is N ₁ , the total amount W ₁ of toner consumed by image formation on this transfer material is W ₁ =
It can be represented by wN ₁ . Here, for example, when the number of dots N ₂ is the total number of dots formed after the toner is replenished in the toner storage container, the total amount W ₂ is the total amount of the toner consumed by the previous image formation. Total amount W ₂
And W ₂ = wN ₂ .

The toner image formed on the surface of the photosensitive drum is transferred onto the surface of the transfer material conveyed by the paper feeding device.
It is transferred via a transfer charger. The transfer material after the toner image transfer is discharged to the outside of the image forming apparatus main body after the toner image is fixed by the fixing device. On the other hand, after the transfer of the toner image, the transfer residual toner on the surface of the photosensitive drum is removed by a cleaner, and the photosensitive drum is used for the next image formation.

In the above-described laser beam printer, the toner contained in the toner container is sequentially consumed as the image is formed, and the remaining amount of toner in the toner container gradually decreases.

The toner remaining amount detecting device according to the present invention accurately detects the remaining amount of toner in the toner container. The principle is based on the fact that the amount of toner adhered to the electrostatic latent image per dot formed by one dot of laser light is constant, as described above.

FIG. 1 is a block diagram of the toner remaining amount detecting device. The toner remaining amount detecting device includes an AND gate (logical product forming means) 101 that performs a logical product of a print data output clock and print dot data, a counter unit 102 that counts the number of output signals generated by the AND gate 101, and a counter unit. Data bus 105 that sequentially outputs the count number from 102, memory 103 that sequentially updates and stores the count number, and outputs the updated count number, data that outputs the cumulative count number accumulated in memory 103 The toner in the toner storage container is determined by the bus 107, the adder 104 that adds the count number sent from these data buses 105, 107 and the cumulative count number, and the cumulative count number after being added by the adder 104. And a processing device 106 for determining the remaining amount.

Next, FIG. 2 shows a timing chart of the above-described embodiment.

First, the print data output clock 201 is input to the AND gate 101. Similarly, print dot data 202 is input to the AND gate 101. Then, the AND gate 101 outputs a logical product output signal 203 as a logical product. The number of this signal is counted by the counter unit 102 (“6” in FIG. 2), and this count number and the cumulative count number stored in the memory 103 in advance are added by the adder 104.

Based on the added count number, the processing device 106 determines the toner remaining amount. Counter part 1
The number of AND output signals counted by 02 corresponds to the number of dots of the electrostatic latent image formed on the surface of the photosensitive drum. Therefore, the adder 1 calculates the cumulative count number from the memory 103 and the count number from the counter unit 102.
The result of addition in 04 is directly the total number of dots of the electrostatic latent image formed so far and having the toner attached thereto. Therefore, the total consumption amount of toner can be accurately detected by calculating the product of the cumulative count number of the dots and the amount of toner attached per dot by the processing device 106. Therefore, if the total amount of toner stored in the toner storage container is measured in advance, the total amount of toner consumed can be subtracted from this measured value to accurately detect the remaining amount of toner in the toner storage container. You can <Second Embodiment> In the first embodiment described above, the AN
Although the logical product output signal 203 from the D gate 101 is directly input to the counter unit 102, in the second embodiment,
A case where the image forming apparatus has a toner mode setting unit that selects the presence / absence of toner saving setting will be described. When the toner saving setting is turned ON, for example, assuming that the toner consumption amount is set to 1/2 of the normal amount, the above-described embodiment does not
A large error occurs between the actual toner consumption amount and the calculated toner consumption amount. This embodiment corrects this error.

When the image forming apparatus can select the presence or absence of toner saving setting, the number of AND output signals by the AND gate 101 and the frequency division value by the toner saving mode setting data bus 301 as shown in FIG. 3 are set. Possible frequency divider 3
Through 02, by counting with the counter unit 303,
By eliminating the above-mentioned error, the toner consumption amount can be accurately detected as in the first embodiment.

The timing chart of FIG. 4 shows the case where the toner saving mode is set to 1/2, that is, the amount of toner attached per dot is reduced to 1/2.

In the present embodiment, the case where the toner consumption amount is halved has been described as an example, but the present invention is not limited to this, and the toner consumption amount can be set to another ratio.

[0026]

As described above, according to the present invention,
By calculating the cumulative count number of dots forming the electrostatic latent image from the print dot data and calculating the consumed toner amount based on the cumulative count number and the toner amount adhered per dot, the toner The remaining amount of toner in the storage container can be accurately detected.

[Brief description of drawings]

FIG. 1 is a block diagram of a toner remaining amount detecting device according to a first embodiment.

FIG. 2 is a timing chart of the toner remaining amount detecting device according to the first embodiment.

FIG. 3 is a block diagram of a toner remaining amount detecting device according to a second embodiment.

FIG. 4 is a timing chart of the toner remaining amount detecting device according to the second embodiment.

[Explanation of symbols]

 101 Logical Product Forming Unit (AND Gate) 102 Counter Unit 103 Memory 104 Adder 105 Data Bus (Counter) 106 Processing Device 107 Data Bus (Memory) 201 Print Data Output Clock 202 Print Dot Data 203 Logical Product Output Signal 301 Toner Saving Mode setting data bus 302 Frequency divider 303 Counter section 401 Frequency divider output signal

Claims (2)

[Claims] 1. A toner remaining amount detecting device for detecting the remaining amount of toner in a developing container, which is consumed by being attached to an electrostatic latent image formed on an image carrier as a set of dots based on print dot data. , A logical product forming section that obtains a logical product of a print data output clock and the print dot data, a counter section that counts the number of output signals output from the logical product forming section, and a count number that is sequentially updated. A memory for storing, an adder for adding the count number output from the counter unit and the count number output from the memory, and storing the added count number in the memory as a cumulative count number; The amount of toner consumed attached to and consumed by the electrostatic latent image is calculated based on the cumulative count number output from the container and the amount of toner attached per dot. Rutotomoni, and a processing device for detecting the remaining amount of toner in the developing container from the toner amount accommodated in the toner container at the beginning and digestion expenses toner amount, the toner remaining amount detecting apparatus characterized by. 2. A toner mode setting means for selecting whether or not toner saving is set, frequency dividing the output signal from the logical product forming section based on the output of the toner mode setting means, and outputting the frequency-divided output signal. The toner remaining amount detecting device according to claim 1, further comprising: a frequency dividing device for inputting to the counter unit.