JPH0519628A - Developing device for electrophotographic printer and toner empty sensor - Google Patents

Abstract

PURPOSE:To surely display the empty of toner when the toner in a developing device is reduced by providing a toner empty sensor. CONSTITUTION:This developing device is provided with a case 2 where the toner 3 is stored, a sleeve 5 which holds the toner 3 stored in the case 2 and sticks it on an electrostatic latent image on a photosensitive drum, a blade 4 which regulates the amount of the toner stuck on the sleeve 5, a mixer 1 which supplies the toner 3 to the sleeve 5 while the toner 3 in the case 2 is stirred by a stirring blade 1a, and the toner depletion sensor S. The sensor S is attached to the stirring blade 1a of the mixer 1, and actuated by a set load which the stirring blade 1a receives from the toner 3 at the time of stirring and detects the empty of the toner. The sensor S is provided with a switch 10 attached to the stirring blade 1a of the mixer 1 which rotates around a rotary shaft 7, a shaft 9 and a plate 6 which is displaced with reference to the switch 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer, and more particularly, to a developing device and a toner empty sensor for placing toner on a sleeve and adhering the toner onto a photosensitive drum.

[0002]

2. Description of the Related Art Conventionally, a toner empty sensor of this type displays toner empty at a predetermined number by calculating the number of printed sheets based on the number of rotations of a photosensitive drum on which an electrostatic latent image is formed.

[0003]

The toner empty sensor of the conventional developing device described above displays the toner empty by calculating the number of printed sheets based on the number of rotations of the drum. Therefore, even if the print density for one sheet is low. , It is decided by the number of prints, so despite the fact that there is enough toner,
There is a drawback that the toner empty is displayed.

An object of the present invention is to provide a developing device and a toner empty sensor for an electrophotographic printer that solves the above problems.

[0005]

In order to achieve the above object, a developing device of an electrophotographic printer according to the present invention has a case, a sleeve, a mixer, a toner empty sensor, and a toner tank. A developing device of an electrophotographic printer that adheres toner to an electrostatic latent image on a photosensitive drum and develops it into a visualized image.A case stores toner, and a sleeve stores toner inside the case. The mixer holds the toner in order to attach it to the photosensitive drum, the mixer supplies toner to the sleeve while stirring the toner in the case with the stirring blade, and the toner empty sensor is attached to the stirring blade of the mixer. The stirring blade operates at the set load received from the toner during stirring,
The toner remaining amount in the case is detected, and the toner tank receives the signal from the toner empty sensor and replenishes the toner in the case.

Further, the toner empty sensor according to the present invention has a switch and a plate, and is used in an electrophotographic printer for adhering toner to an electrostatic latent image on a photosensitive drum and developing the toner into a visible image. A toner empty sensor used in a developing device, wherein the switch is attached to a stirring blade of a mixer for stirring toner in a case of the developing device, and a plate is supported by the stirring blade of the mixer and the switch is mounted on the switch. It is arranged so as to be displaceable with respect to, and is always urged in a direction away from the switch to operate the switch under a set load that the stirring blade receives from the toner.

[0007]

In the present invention, the stirring blade of the mixer for stirring the toner detects the load received from the toner and outputs the remaining amount of toner.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a developing device of an electrophotographic printer according to the present invention, and FIG. 2 is a diagram showing a toner empty sensor according to the present invention.

In FIG. 1, the developing device of the electrophotographic printer according to the present embodiment holds a case 2 for storing the toner 3 and the toner 3 in the case 1 and attaches the toner 3 to the electrostatic latent image on the photosensitive drum. A sleeve 5, a blade 4 that regulates the amount of toner that adheres to the sleeve 5, a mixer 1 that supplies the toner 3 to the sleeve 5 while stirring the toner 3 in the case 2 with a stirring blade 1a, and a toner empty sensor S. have.

As shown in FIG. 2, the toner empty sensor S is attached to the stirring blade 1a of the mixer 1, and operates at a set load which the stirring blade 1a receives from the toner 3 during stirring.
The toner empty is detected, and the switch 10 attached to the stirring blade 1a of the mixer 1 that rotates around the rotary shaft 7, the shafts 9 and 9 protruding forward with respect to the switch 10, and the shafts 9 and 9 Supported switch 1
It has a plate 6 that is displaced with respect to 0, a stopper 11 that prevents the plate 6 from slipping out of the shaft 9, and a spring 8 that biases the plate 6 forward.

In the toner empty sensor S, the plate 6 is separated from the switch 10 by the spring force of the spring 8 in the state of FIG. 2, and the switch 10 is in the OFF state.

In the embodiment, when a large amount of toner 3 is contained in the case 2, the load of the toner 3 is applied to the plate 6 by rotating the stirring blade 1a of the mixer 1. As a result, the spring 8 is compressed and the plate 6 pushes down the contact of the switch 10 to turn it on. At this time, the toner empty display is not performed.

When the amount of toner 3 in the case 2 is small, the load of the toner 3 on the plate 6 is reduced, the plate 6 is positioned away from the switch 10 by the spring 8, and the switch 10 is turned off. At this time, the toner empty display is performed because the remaining toner amount is low.

(Second Embodiment) FIGS. 3 and 4 are views showing a second embodiment of the present invention.

In this embodiment, the case 2 shown in the first embodiment is provided with the toner tank 12, and the toner is supplied from the toner tank 12 to the case 2 based on the detection signal from the toner empty sensor S. . Incidentally, FIGS.
The structure of the toner empty sensor S shown in is the same as that shown in FIGS.

In the embodiment, the toner 3 is placed in the case 2.
When a large amount of toner is included, the load of the toner 3 is applied to the plate 6 by rotating the mixer 1. As a result, the switch 10 is turned on. At this time, the toner tank 12
Toner 3 is not supplied from.

When the amount of toner 3 in the case 2 is small, the load of the toner 3 on the plate 6 is reduced and the switch 10 is turned off. Therefore, at this time, the toner 3 is supplied from the toner tank 12, and when the load on the plate 6 becomes large, the switch 10 is turned on, and the supply of the toner 3 from the toner tank 12 is stopped.

[0019]

As described above, according to the present invention, by providing the toner empty sensor, it is possible to surely display the toner empty when the toner in the developing device is low.

Further, since the toner empty sensor accurately detects the amount of toner in the case, it is possible to reliably detect that the amount of toner in the case is low and replenish the toner in an appropriate amount.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a detailed view showing the toner empty sensor of the first embodiment.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a detailed view showing a toner empty sensor of Example 2.

[Explanation of symbols]

1 mixer 2 cases 3 toner 4 blades 5 sleeve 6 plates 7 rotation axis 8 springs 9 shaft 10 switches 11 stopper 12 Toner tank S Toner empty sensor

Claims (2)

[Claims] 1. An electrophotographic printer having a case, a sleeve, a mixer, a toner empty sensor, and a toner tank, which adheres toner to an electrostatic latent image on a photosensitive drum and develops it into a visualized image. The case is for storing toner, the sleeve is for holding the toner in the case to adhere to the photosensitive drum, and the mixer is for stirring the toner in the case by a stirring blade. The toner is supplied to the sleeve while stirring, and the toner empty sensor is attached to the stirring blade of the mixer, and operates at a set load received from the toner by the stirring blade at the time of stirring to detect the remaining amount of toner in the case. The electrophotographic toner cartridge is characterized in that the toner tank receives the signal from the toner empty sensor and replenishes the toner in the case. A developing unit of the printer. 2. A toner empty sensor having a switch and a plate, which is used in a developing device of an electrophotographic printer for adhering toner to an electrostatic latent image on a photosensitive drum and developing the electrostatic latent image into a visible image. , The switch is attached to a stirring blade of a mixer that stirs the toner in the case of the developing device, and the plate is supported by the stirring blade of the mixer so as to be displaceable with respect to the switch. A toner empty sensor, which is urged in a direction away from the switch and operates the switch under a set load which the stirring blade receives from the toner.