JPS62237477A - Image forming device - Google Patents

Abstract

PURPOSE:To obviate a development failure caused by a flocculation of a toner, and to appropriately execute a replacement of a developing device due to non- existence of the toner, by providing a toner quantity detecting means in the vicinity of a developing means of the developing device, and executing a display of a shake and a replacement of the developing device by a signal of its toner quantity detecting means. CONSTITUTION:When the vicinity of a developing sleeve 2 has become a state that no toner exists, due to an image forming operation, a toner quantity detecting means 5 detects a fact that no toner exists in the vicinity of the developing sleeve 2, and gives an instruction to oscillate a cartridge, to a user. When the user shakes the cartridge in accordance with this instruction, a toner 4 is collected again to the vicinity of the developing sleeve 2 and printing can be executed. In this case, in case the toner 4 is gone entirely, after the first instruction for the shape, a toner non-existence signal is generated continuously, therefore, in this case, a signal for replacing the cartridge is displayed.

Description

Detailed Description of the Invention 41 Object of the Invention [Field of Industrial Application] The present invention relates to an image forming apparatus, more specifically, an image forming apparatus which forms a latent image on an image carrier by means of a latent image forming process means disposed around the image carrier. The present invention relates to an image forming apparatus that forms a latent image and attaches toner to the latent image using a developing means to form a visible image.

[Conventional technology]

With the recent development of office automation, there is an increasing need for small and lightweight image forming apparatuses that can be used by individuals. Therefore, in order to improve the service performance of a small-sized image forming apparatus, it has been proposed that the main part of one image forming process is made into a cartridge, as disclosed in Japanese Patent Application Laid-open No. 198053/1983.

For example, in an electrophotographic image forming apparatus, a photosensitive drum, a cleaning device, a developing device, a charging device, etc. are all assembled into a cartridge container, or the developing device is placed in a separate cartridge container. A two-force-trige system has been proposed in which the device is mounted internally.

These cartridge systems allow users to: 1. In order to improve convenience, the cartridge container equipped with the developing device is often a disposable type that is replaced when the toner is empty.

[Problem that the invention seeks to solve]

In such a cartridge-type image forming apparatus, it is desirable to increase the toner capacity in the developing device in order to reduce running costs. However, even if the toner capacity is simply increased, the toner near the developing means often runs out due to toner aggregation before all of the toner in the hopper is used up, resulting in an image that is out of toner even though there is toner. There was a problem in that the developing device had to be replaced before the end of its life.

Furthermore, image forming apparatuses are becoming smaller year by year, and in order to fill a small space with a large amount of toner, it is becoming difficult to form a hopper into a shape that makes it easy to transport toner.

Therefore, even if a toner stirring mechanism is not provided in the hopper, or even if an attempt is made to convey the toner using only a simple stirring blade, a large amount of toner remains in the hopper.

For example, in the shape of the hopper 81 as shown in FIG. 8a, the toner 4 falls under its own weight and is supplied to the developing sleeve 8z serving as a developing means, but the toner itself is subjected to pressure due to its own weight and tends to aggregate. Furthermore, the triboelectric element becomes abnormally high, resulting in a tall developing device, which hinders miniaturization and weight reduction. Furthermore, even if the width is increased like the developing device 81 shown in FIG. 8, the height will be slightly lower than that of the developing device shown in FIG. The problem was that it was not very effective.

The present invention solves the above-mentioned problems, does not produce an image that is out of toner until the number of sheets that can be printed during the lifetime of the cartridge, and can increase the toner capacity without being limited by the size or shape of the cartridge container. The purpose is to obtain a forming device.

Summary: Structure of the Invention [Means for Solving the Problems] The present invention forms a latent image on an image bearing member by a latent image forming process means disposed around the image bearing member, and forms a latent image on the latent image by a developing means. In an image forming apparatus that attaches toner to form a visible image, a developing device including a developing means and a toner hopper is attached to a cartridge container that is detachable from the main body of the apparatus, and a toner amount detecting means for detecting the amount of toner is attached to the developing means. established,
A holding means is provided for holding a toner out signal generated from the toner amount detecting means when the cartridge container is mounted, even after the cartridge container is mounted, and the timing of shaking and replacing the developing device is determined based on the signal from the holding means. An image forming apparatus is characterized in that it includes a display means for displaying a time.

[For production]

When the cartridge container is attached to the apparatus main body, the toner amount detection means detects the presence or absence of the toner amount near the developing means, and this detection signal is held in the holding means even after installation, and the signal from this holding means and the amount of toner in the cartridge container are The time to shake the developer and the time to replace it are determined and displayed based on the detection signal output from the toner amount detection means when the developer is installed next time. There is no mistake in the replacement timing, and the structure is simple because the toner amount detecting means only needs to be disposed at one location.

〔Example〕

Figure 1 shows a laser beam as an image forming apparatus of the present invention.
FIG. 1 is a cross-sectional view showing a printer (hereinafter referred to as L-B-P). In FIG. 1, reference numeral 10 denotes a cartridge container that can be attached to and removed from the apparatus main body 100, and a photosensitive drum 1 is supported within this cartridge container 10 so as to be rotatable in the direction of the arrow.

Also, a toner hopper 3 supporting a developing sleeve 2 arranged in parallel with the photosensitive drum 1 so as to be rotatable in the direction of the arrow. A cleaning device 8 and a primary charger 9 are provided.

Is there a laser unit on the device main body 100 side? ), a scanner unit 6 including a polygon mirror and a correction lens system, a mirror 11 that guides the laser beam 12 emitted from the scanner unit 6 onto the photosensitive drum 1 through an opening 10a into the cartridge container 10, and an opening 10b of the cartridge container 10. A pre-exposure light source 13 that exposes the photosensitive drum 1 through a cassette) 1
Paper feed roller 14 that feeds the transfer material 15 in 6. A pair of registration rollers 17, a transfer charger 7, a fixing device 18, and a reversing guide 19 are provided for discharging the transfer material 15 onto a tray 20 face down.

The laser beam 12 modulated by the image signal emitted from the scanner unit 6 is reflected by the mirror 11 and is reflected by the primary charger 9.
The light is irradiated onto the photosensitive drum l which is uniformly charged.

The electrostatic latent image formed on the photosensitive drum 1 by the irradiation with the laser beam 12 is developed with the toner 4 coated on the developing sleeve 2 to which an alternating bias with DC (direct current) superimposed is applied, and transferred. The image is transferred onto the transfer material 15 by the transfer corona discharge from the charger 7.

After the transfer, the toner remaining on the photosensitive drum 1 is cleaned by a cleaning device 8, and then the charging history of the photosensitive drum 1 is erased by pre-exposure 13, and the same process as described above is repeated.

The transfer material 15 in the cassette 16 is fed by a paper feed roller 14 and a pair of registration rollers 17, and after the toner image on the photosensitive drum 1 is transferred as described above, it passes through the fixing device 18 and is heated or pressurized. The toner image is permanently fixed. Thereafter, the sheet passes through the first inverted image 19 and is discharged onto the tray 20 face down.

As a result of the image forming operation described above, when the area near the developing sleeve 2 becomes empty of toner as shown in FIG. When the user shakes the cartridge in accordance with this instruction, the toner 4 gathers again in the vicinity of the developing sleeve 2° as shown in FIG. 3, and printing becomes possible.

At this time, if the toner 4 is completely depleted, a toner out signal is generated after the first shake instruction, and therefore a cartridge conversion signal is displayed at this time.

FIG. 4 is a simple schematic diagram of the toner amount detection means. Due to the AC bias from the power source 45 applied to the developing sleeve 2, a current corresponding to the impedance between the developing sleeve 2 and the conducting wire 5 is applied to the conducting wire 5, which is stretched parallel to the developing sleeve 2 and serves as a toner amount detection means. The flowing current is rectified by a rectifier circuit 41 and converted into a DC voltage 42, which is then passed through a comparator 43.
generates an output compared with a reference voltage 44.

The impedance between the developing sleeve 2 and the conducting wire 5 changes depending on the amount of toner due to the difference in dielectric constant and the difference in resistance between the toner and air, and the amount of toner is detected using this change. At this time, the cartridge container 10 serves as the toner amount detection means.
There is almost no increase in cost because the conductor is simply attached to the wire.

FIG. 5 is a flowchart for indicating replacement and shake of the cartridge container 10, that is, the developing unit 3, in response to the toner empty detection signal. After inserting the cartridge into the device body! The door switch on the A device body is O.
N is applied, developing bias is applied, and the absence of toner is detected (
Step 5-1.5-2.5-3) If a toner out condition is detected at this time, if the toner out condition was detected in the previous toner out condition, the condition may be It is stored in the memory of a microcomputer (not shown) installed in the forming operation, so it instructs cartridge replacement (
Step 5-4.5-5.5-6).

On the other hand, if the no-toner state is not held in the memory, an instruction is given to shake the cartridge (step 5-7).
, At this time, enter the toner out state in the memory and install/remove the cartridge (steps 5-8 and 5-9). If the toner out state is not detected after inserting the cartridge, first reset the memory. , return to the toner present state and display that printing is possible. Thereafter, after printing is started, the same flow as shown in the figure is repeated (steps 5-10.5-11.5-12).

In this way, the amount of toner near the developing means in the cartridge must be checked when the cartridge is inserted (step 5-13), and a signal instructs the user to replace or shake the cartridge before inserting the cartridge. FIG. 6 is a side view showing an example of a holding means for holding the detection result of the toner amount detecting means.

When there is no toner in the developing device 3 near the developing sleeve, the toner amount detecting means 5 detects that there is no toner, and at the same time the motor 61 rotates a certain amount, and the motor 61 rotates by a certain amount to freely rotate the developing device 3 through the gears 64 and 65. A rotary plate 63 that is supported by the shaft rotates by a certain angle.

The rotating plate 63 is divided into a part 63a that reflects light and a part 63b that does not reflect light (for example, painted black), and in the developing device 3 in which the no-toner detection means 5 has never worked, the part 63b painted black is a reflective type. In the developing device 3 facing the optical path of the photosensor 62 and on which the toner-free detection means 5 has already been activated, the light-reflecting portion 63a faces the optical path of the photosensor 62.

In this way, it can be determined from the output of the reflective photo sensor 62 whether the developing device 3 is already in a toner-free state or not, so even if the developing device 3 is replaced midway through, for example, the device will be reliably compatible with that developing device. You can now see the number of out-of-toner detections.

It is possible to display a determination whether the developing device 3 should be replaced or shaken.

At this time, the amount of rotation of the rotary plate 62 and the area of the black painted portion 63b vary depending on the shape of the developing device 3 and other factors, depending on the shape of the developing device 3 and other factors. You can change it as appropriate depending on how it falls into the vicinity. In this way, for example, it is possible to display the need to replace the developing device when the toner is detected for the third time.

FIG. 7 shows another embodiment, in which a toner amount detection sensor 75 is placed outside the cartridge. In this case, since the toner amount detection sensor 75 is not disposable, there is an advantage that the cost of the cartridge itself does not increase at all. For example, in the case of magnetic toner, the toner amount detection sensor 75 may be one that detects changes in inductance using a coil or the like, or one that makes the cartridge partially transparent and uses a photosensor to detect from the transparent part. is available. Furthermore, as one display means, one using light or sound can be applied.

C. Effects of the Invention As described above, according to the present invention, a toner amount detecting means is provided near the developing means of the developing device, and a signal from the toner amount detecting means is used to indicate the deviation of the developing device and the need for replacement. Therefore, it is possible to eliminate developing defects due to toner aggregation and to appropriately replace the developing device due to no toner. As a result, there is no need for a special stirring rod or other toner conveying means in the developing device, and a large amount of toner can be packed into the developing device by utilizing the narrow space of the device itself, regardless of the toner conveying performance of the developing device. Can be made into any shape.

In addition, by detecting the presence or absence of toner when the cartridge is installed, it is possible to distinguish between a developing device shake indication and a replacement indication, and by retaining the presence or absence of past toner empty detection on the developing device side, for example, Even if the developing device is replaced with another developing device before the toner is completely depleted (for example, if the developing device is replaced with one of a different color), it is possible to display a runout indication and a replacement indication corresponding to each developing device.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an image forming apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are the same diagrams showing the state of toner in a developing device, and FIG. 4 is an example of a toner amount detection means. FIG. 5 is a flowchart showing the operation of displaying the state of toner in the developing device; FIG. 7
The figure is a sectional view showing another embodiment of the present invention, FIG. 8(a)-
(b) is a sectional view showing a conventional developing device. 1 is an image bearing member (photosensitive drum), 2 is a developing means (developing sleeve), 3 is a developing device, 5 and 75 are toner amount detecting means, 1
0 is a cartridge container, and 100 is a device main body.

Claims (1)

[Claims] (1) In an image forming apparatus, a latent image is formed on an image carrier by a latent image forming process means disposed around the image carrier, and a toner is attached to the latent image by a developing means to form a visible image. A developing device including a developing means and a toner hopper is attached to a cartridge container that is detachable from the main body, and a toner amount detecting means for detecting the amount of toner is provided on the developing means, and when the cartridge container is attached, the toner amount detecting means generates the toner amount. The developing device has a holding means for holding the toner out signal even after the cartridge container is installed, and a display means for indicating when to shake the developing device and when to replace it based on the signal from the holding means. image forming device.