JPH0568701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a toner replenishing device used in an electrostatic copying apparatus that performs dry development.

Conventional structure and its problems Conventionally, the toner replenishment device of a dry type electrophotographic copying machine generally has a toner remaining amount sensor disposed on the lower side wall of the toner hopper, which has a toner replenishment roller in the lower opening, and is housed in the toner hopper. The device is configured to detect the presence or absence of toner that is being used.

Then, the toner remaining amount sensor detects the change in the toner pressure, distinguishes whether the toner is above or below the sensor surface, and if it is below, displays an indication that the toner amount is low. I have to.

However, since toner has the property of easily sticking and adhering, if toner adheres to the surface of the remaining toner amount sensor or solidifies after adhering, the toner is consumed and the There was a drawback that there was no indication that the amount of remaining toner was low even if the amount decreased to . For this reason, if you continue to use the device, the toner in the developing unit will run out, and you may notice that the toner in the toner hopper is running out only after the image becomes pale, or even if you replenish the toner, it will not become darker for a while. It had the following drawbacks.

Purpose of the Invention The present invention aims to eliminate the drawbacks of the above-mentioned conventional examples, and provides a highly reliable toner replenishing device that stably maintains the detection function of the toner remaining amount sensor. .

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a hopper having an opening for toner replenishment at the bottom, a screw coil disposed within the hopper for agitating and transferring the toner, and a screw coil provided on the inner wall of the hopper. An electrostrictive vibrator sensor is provided, and a diaphragm is provided such that one side is close to the electrostrictive vibrator sensor and the other part is slidably engaged with the screw coil. It is composed of

DESCRIPTION OF EMBODIMENTS The present invention will be described below based on illustrated embodiments.

FIG. 1 is an overall perspective view of a toner replenishing device according to the present invention, FIG. 2 is a cross-sectional plan view taken along line A-A, FIG. 3 is a cross-sectional plan view taken along line B-B, and FIG. 4 is a cross-sectional plan view taken along line C-C. A line cross-sectional view is shown.

In those figures, 1 has magnetic toner 2 inside.
The hopper is equipped with a toner filling opening and has a vertical first storage section _1a and a horizontal second storage section 1b _.
It is made up of. 3 is a rotating lid that opens and closes the toner filling opening on the first storage section _1a of the hopper, and 4 is an upper lid that seals the second storage section _1b of the hopper 1. Reference numeral 5 denotes a right-handed helical screw coil, one end of which is press-fitted into a boss 6, and the other end fitted into an impeller-shaped sleeve 7 having four protrusions on its outer periphery, as shown in FIG. There is. The boss 6 and the sleeve 7 are fixed to a rotating shaft 8 whose both ends are rotatably supported on the side wall of the second storage section 1 _b , and rotate integrally with the screw coil 5. There is. 9 indicates an oil seal. Reference numeral 10 denotes a rectangular plate-shaped rotating blade made of an elastic material such as rubber or plastic, whose one end is fixed to one side of the rotating shaft 8 with a screw or the like, and when the other end rotates, the second storage section 1
It has a length that reaches the bottom wall of _b , and is configured to scoop up the magnetic toner 2 at the bottom. The rotating shaft 8 is rotated counterclockwise by a drive system to be described later, and the screw coil 5 transports the magnetic toner in the direction of arrow D. Here, the outer diameter of the rotating shaft 8 is smaller than the inner diameter of the screw coil 5, and a gap is provided between the rotary shaft 8 and the screw coil.

Similarly, 11 is a left-handed helical screw coil, 12 is a boss, 13 is a sleeve, 14 is a rotating shaft, 15 is a rotating blade, and the above-mentioned screw coil 5, boss 6, sleeve 7, rotating shaft 8, It has exactly the same configuration as the rotating blade 10, and is arranged in the opposite direction. The rotating shaft 14 is rotated counterclockwise by a drive system, which will be described later, so that the screw coil 11 transports the magnetic toner in the direction of arrow E. Therefore, when the rotating shafts 8 and 14 rotate counterclockwise, the magnetic toner is transported in the directions of arrows D and E by the screw coils 5 and 11, respectively. At the same time, since the rotating blades 10 and 15 disposed at the opposite end are also rotating, D
The magnetic toner sent in the direction shown in FIG. It is handed over to 5.

As described above, since the magnetic toner is transferred while being stirred by the screw coil and the rotary blade in the second storage section _1b , it is possible to prevent the magnetic toner from solidifying in the hopper.

Providing a gap between the screw coil and the rotating shaft to give fluidity to the magnetic toner even between one pitch of screw coils also has a more effective effect.

Reference numeral 16 denotes a replenishment roller, which is rotatably disposed parallel to the screw coil and approximately at the bottom of the center of the second storage section _1b . In this embodiment, a recess corresponding to the length of the replenishment roller 16 is formed at the bottom between the screw coils, and a slight gap is provided between the screw coil and the replenishment roller. A slit-like opening or a plurality of elongated openings H for supplying magnetic toner to a developing device (not shown) is formed in this recess.

As shown in FIG. 5, magnets 17 such as rubber magnets are provided along the entire length of both shoulders of this recess. The magnet 17 is an anisotropic type permanent magnet, which is magnetized N-S in the thickness direction, and is arranged so that the concentration of magnetic lines of force is located on the replenishment roller 16 side, as shown in FIG. be. Therefore, the supply roller 16
A magnetic curtain is formed between the magnet 17 and the magnet 17 due to the concentration of magnetic lines of force, and the magnetic toner is attracted to the magnet 17 and forms a seal between the magnetic toner and the replenishment roller 16, preventing leakage to the developer side. do not have.

The replenishment roller 16 has a flat part _{16 a} cut out in the axial direction on a part of its outer periphery, and when the replenishment roller 16 rotates once, a magnet 17 is attached to the flat part.
The magnetic toner adhering to the toner is scraped off and dropped through the opening H at the bottom of the recess, and is replenished to the developing device.

By arranging anisotropic type magnets with magnetic lines of force concentrated at their tips on both shoulders of the bottom concave part of the second storage section _1b facing the replenishment roller, the action of the magnetic lines of force allows the magnets to be removed from the gap between the replenishment roller and the replenishment roller. Natural fall of the magnetic toner can be prevented, and furthermore, by increasing the magnetic force, the gap between the replenishment roller and the inner wall of the recess can be designed to be large, thereby preventing the inability to replenish the magnetic toner due to an increase in the rotational load of the replenishment roller 16.

18 is a gear pivotally supported by the rotating shaft 8, 19 is a gear pivotally supported by the rotating shaft 14, and power from a drive source (not shown) is driven via a driving gear 20 and a transmission gear 21. There is. 22 is an intermediate gear that transmits the rotation of gear 19 to gear 18;
It is rotatably supported on the shaft of the supply roller 16. 23 is pivotally supported by the shaft of the replenishment roller 16, and power from a drive source (not shown) is transmitted through a drive gear 24. The supply roller 16 is normally controlled by a control system to rotate clockwise and to stop after each rotation. Note that the rotation may be stopped every several rotations depending on the amount of replenishment, and this can be selected freely.

Reference numeral 25 denotes a sensor for detecting the remaining amount of magnetic toner. In this embodiment, an electrostrictive vibrator is used, and the sensor 25 is arranged on the inner wall of the second storage section 1 _b with the sensor surface facing inward.

26 is a diaphragm made of elastic material such as plastic such as polyester film, rubber, metal plate, etc.
It is arranged close to the sensor 25.

As shown in FIG. 7, the diaphragm 26 has a bent piece 26
_A is formed, one side is attached to the sensor 25 via a sponge seal 27, and a bent piece _26a is slidably engaged with the screw coil 5. Note that the diaphragm 26 may be directly attached without using the sponge seal 27.

When the screw coil 5 rotates, the bending piece 26
_a is bent in the direction of arrow D. However, when the screw coil 5 rotates further, the engagement is disengaged and returns in the direction of arrow E by elastic force, and this operation is repeated while the screw coil 5 rotates. Therefore, the diaphragm 26 vibrates periodically, and this vibration is transmitted to the sensor 2.
5, and the magnetic toner adhering to the sensor surface is repelled. This action removes the magnetic toner adhering to the sensor surface, eliminating the problem of the sensor detecting the presence of magnetic toner even though there is almost no magnetic toner in the hopper due to adhesion of magnetic toner. Ru. Therefore, the sensor stably performs the remaining amount detection operation, and the problem of a decrease in image density due to insufficient supply of magnetic toner can be prevented.

Reference numeral 28 denotes a regulating sheet such as a plastic film made of polyester or the like or a thin plate, which is disposed on the inner wall of the first storage section _1a of the hopper 1. The lower opening of the first storage section _1a that communicates with the second storage section _1b is connected to the rotating shaft 1.
The screw coil 5 has a width corresponding to one end of the screw coil 5 and the rotating blade 15 fixed to the magnetic toner inlet side end of the magnetic toner 4. The regulation sheet 28 is the second
As shown in the figure, the length is such that it covers almost the entire screw coil 5 in the diametrical direction from the right end of the opening of the first storage section _1a , and has a width slightly narrower than the width of the first storage section. There is. This regulation sheet 28 prevents the magnetic toner in the first storage section 1 _a from being directly transferred by the screw coil 5 .

Here, the function of the regulation sheet 28 will be further explained using FIG. 8. FIG. 8 is a diagram showing the relationship between the amount of magnetic toner and the drive load torque of the rotating shafts 8 and 14. The curve A shows the case without the regulation sheet 28, and the curve B shows the case with the regulation sheet 28. It shows. As is clear from the figure, in the case of curve A, the amount of magnetic toner in hopper 1 is 200g.
When the amount increases, the load torque increases rapidly, and 500
When it comes to g, it exceeds 9Kg-cm. This is because even though there is a sufficient amount of magnetic toner in the second storage section _1b , the magnetic toner that has been stirred and transferred by the rotary blade 15 is not delivered to the screw coil 5 on the right side in the perpendicular direction. This is because the screw coil 5 tries to directly feed the magnetic toner in the first storage section _1a to the back side, which compresses the magnetic toner and requires a large force to feed it. On the other hand, when the regulation sheet 28 is disposed above the screw coil 5, the screw coil 5 only needs to feed the magnetic toner that is transferred by the rotary blade 15, so the load torque is not large as shown by the curve B. Does not increase.

Next, the operation of the above embodiment of the present invention will be explained.

When the rotating lid of the hopper 1 is opened and the magnetic toner 2 is stored in the first storage portion _1a , and a drive source (not shown) is driven, the rotating shafts 8 and 14 are rotated counterclockwise.

The magnetic toner 2 is sent into the screw coil 5 by the rotating blade 15. The magnetic toner is moved in the direction of arrow D by the screw coil 5, and when it reaches the rotating blade 10, it is sent in the direction of arrow F. The magnetic toner that has reached the boss 12 is sent in the direction of arrow E by the rotation of the screw coil 11.

Through the above-described operations, the magnetic toner is stored in the second storage section _1b and is constantly circulated within the second storage section _1b . The magnetic toner placed in the first storage section _1a moves to the second storage section _1b , but when a predetermined amount is reached, the magnetic toner moves in the direction of arrow G, and the toner regulation sheet 28 and the The size of the enclosing area between the storage portion _1b and the bottom becomes the size of the inflow port, and magnetic toner exceeding a predetermined amount does not enter the screw coil 5. When replenishing the magnetic toner 2, move a drive source (not shown) to connect the connecting gears 23,
24 to rotate the replenishment roller 16 once clockwise, a predetermined amount of magnetic toner 2 falls from the opening at the bottom of the second storage section _1b into a developing section (not shown).

Although the above embodiments of the present invention have been described using magnetic toner as an example, the toner is not limited to this, and the same effect can be obtained even if an insulating toner is used.

Effects of the Invention As detailed above, according to the present invention, the toner sensor is vibrated by the vibrating member provided on the side surface of the toner sensor, and the toner near the toner sensor is periodically shaken, so that the toner sensor Toner will no longer adhere to the surface.
The detection operation of the amount of toner in the toner storage section operates stably.

In addition, since the detection of the amount of toner in the toner storage section works stably, the problem of image density reduction due to lack of toner does not occur, and the excellent effect of realizing a dry-type developing device with stable image quality can be achieved. be.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a toner replenishing device according to the present invention, FIG. 2 is a cross-sectional plan view taken along line A-A, FIG. 3 is a cross-sectional plan view taken along line B-B, and FIG. 4 is a cross-sectional plan view taken along line C-C. 5 is an enlarged perspective view of the essential parts of the bottom of the hopper in the embodiment of the present invention, FIG. 6 is the sectional view, FIG. 7 is an enlarged perspective view of the diaphragm, and FIG. 8 is an enlarged perspective view of the toner amount FIG. 3 is a characteristic diagram showing the relationship between drive load torque of a rotating shaft. 1... hopper, 1 _a ... first storage section, 1 _b ...
2nd storage section, 5, 11...screw coil;
8, 14... Rotating shaft, 10, 15... Rotating blade,
16... Supply roller, 17... Magnet, 25... Sensor, 26... Vibration plate, 26 _a ... Bending piece, 2
8...Regulation sheet, H...Opening.

Claims (1)

[Claims] 1. A hopper having an opening for toner replenishment at the bottom, a screw coil disposed within the hopper for agitating and transferring toner, and a sensor surface located near the screw coil in the toner transfer direction of the screw coil. An electrostrictive vibrator sensor is arranged parallel to the inner wall of the hopper, and one surface portion is close to the electrostrictive vibrator sensor, and the other portion is slidably engaged with the screw coil. A toner replenishing device comprising a diaphragm arranged as shown in FIG.