JPS649632B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device used in a printer or the like. More specifically, this prevents the toner from the developing device from spilling out.

Conventionally, the magnet roll or sleep roller of a developing device is not driven independently, but is rotated in conjunction with transport rollers (for example, a transport roller or a fixing roller) located before and after the developing device.

However, if a paper feed failure such as a jam occurs while the recording paper is running, the conveying roller and fixing roller are rotated in the opposite direction to take out the recording paper with the jam or the like generated. At this time, when the magnetic roller and sleeve of the developing device are reversed in conjunction with the conveyance roller and fixing roller, a large amount of toner is supplied to the sleeve, which may cause the toner to spill or when normal operation resumes, a large amount The drawback was that the rotational torque of the magnet roll and sleeve to which toner adhered became unstable.

The present invention has been made in view of the above-mentioned drawbacks, and provides a one-way clutch on the toner carrying means such as the sleeve or magnet roll of the developing device and its rotating shaft to prevent toner powder from spilling into the device. It is another object of the present invention to provide a developing device that can obtain stable rotational torque during subsequent operation.

The present invention will be explained below based on the drawings. 1st
The figure is a side sectional view of a magnetic brush developing device showing one embodiment of the developing device of the present invention. 1 is a cylindrical sleeve. Reference numeral 2 denotes a cylindrical magnet roll, which has a plurality of two different types of magnetic poles alternately. The sleeve 1 is coaxially rotatably provided around the outer periphery of the magnet roll 2. Reference numeral 3 is a toner container for storing and supplying toner powder 4. 5 is a doctor that regulates the amount of supply to the sleeve 1, and 6 is a developing guide. 8 is a recording paper that runs on the developing guide 6 in the direction of arrow b, and 7 is a conveyance roller that conveys the recording paper 8. This developing device is of a sleeve rotation type, and when the sleeve 1 rotates in the direction of the arrow a, toner powder is supplied to the development point located at the shortest distance between the recording paper 8 and the sleeve 1, and the toner powder on the recording paper is A visible image is created by transferring toner powder to an electrostatic latent image.

FIG. 2 is a plan view of this embodiment. 9 is a rotating shaft of the sleeve 1, and 10 is a roller type one-way clutch. 11, 13, and 14 are gears, and 12, 15 are belts for transmitting torque.
3 is a sectional view taken along the line X--Y in FIG. 2, showing the internal structure of the one-way clutch 10. As shown in FIG. 17 is a cam-shaped outer ring, and a plurality of rollers 16 are arranged in a wedge-shaped space formed between the outer ring 17 and the cylindrical inner ring 19. This inner ring 19 is connected to the rotating shaft 9 of the sleeve 1 by a pin or the like.

Next, the operation of the developing device constructed as described above will be described below. During development, the belt 15 is rotated by a drive source such as a motor (not shown). Thereby,
The gear 14 on which the belt 15 is passed rotates, and the conveyance roller 7 connected to the gear 14 also rotates.
Since the conveyance roller 7 is connected to the gear 13, the rotational force of the conveyance roller 7 is transmitted to the gear 11 via the belt 12. Note that the quality of the recorded image will be better if the moving speed of the toner powder 4 due to the rotation of the sleeve 1 is made slightly faster than the traveling speed of the recording paper 8. This setting can be done by making the pitches of the gears 11 and 13 the same and setting only the diameter ratio arbitrarily. This gear 11 is the outer ring 1 of the one-way clutch 10.
It is combined with 7. This outer ring 17 is indicated by the arrow c in Figure 3.
When rotated in the direction, the roller 16 is engaged between the outer ring 17 and the inner ring 19. Therefore, the rotational force of the outer ring 17 is transmitted to the inner ring 19 and the rotating shaft 9 of the sleeve 1 coupled to the inner ring 19. Then, the sleeve 1 rotates in the direction of the arrow a in FIG. 1 to supply the toner powder 4 to a developing point, thereby developing the electrostatic latent image applied onto the recording paper 8.

Next, when a paper feed failure such as a jam occurs while the recording paper is running, it becomes necessary to reverse the conveyance roller 7 and take out the defective recording paper. At this time, if the one-way clutch 10 is not present, the conveying roller 7 is reversely rotated and the sleeve 1 is also rotated in conjunction with the reverse rotation.
If the sleeve 1 rotates in the direction opposite to the direction of the arrow a in FIG. become.

As a result, the toner powder 4 has many chances to fly out of the magnetic field of the magnet roll 2, and the toner powder 4 spills onto the recording paper 8 and the developing guide 6, causing problems such as staining the device and the recording paper. occurs. Further, the return amount of the toner powder 4 is regulated at the position of the doctor 5, and the toner powder 4 is placed under the doctor 5.
If this amount increases, the toner powder 4 will spill out, causing a similar problem. Furthermore, the toner powder 4 that was supplied in large quantities when the sleeve 1 rotated in the direction opposite to the direction of the arrow a in FIG. As long as the toner powder 4 in the toner container 3 is not used up, it remains on the sleeve 1. In this case, when the sleeve 1 rotates, friction occurs between the moving toner and the stagnant toner, the rotational torque of the sleeve 1 increases, and the rotation of the sleeve becomes unstable.

In this embodiment, the gear 11 and the rotating shaft 9 of the sleeve 1
A one-way clutch 10 is provided between the two. Therefore, even if the outer ring 17 connected to the gear 11 rotates in the direction c' opposite to the direction of the arrow c in FIG. and the inner ring 19, the rotational force of the outer ring 17 in the c' direction is transferred to the inner ring 1.
9 and the rotating shaft 9 of the sleeve 1. Therefore, the sleeve 1 will not be reversed, and the above-mentioned problems caused by this will not occur.

Note that although the above description has been made only for a sleeve rotation type developing device, it can be realized in exactly the same manner for a magnetic rotation type developing device.

As described above, according to the present invention, since the one-way clutch is provided which transmits the rotation in the forward direction to the rotating shaft of the toner carrying means and does not transmit the rotation in the reverse direction to the rotating shaft, the toner carrying means is rotated in the reverse direction. In addition to preventing the toner powder from spilling out without causing any problems, stable rotational torque of the toner carrying means can be obtained. Furthermore, since a one-way clutch is provided on the rotating shaft to provide a toner supply means integrated with the toner carrying means, it is possible to prevent reverse rotation even when the toner supply means is removed from the device, and maintenance such as toner supply and cleaning can be prevented. It becomes possible to do this reliably.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a magnetic brush developing device according to an embodiment of the developing device of the present invention, FIG. 2 is a plan view of this embodiment, and FIG. 3 is a sectional view of a one-way clutch. 1... Sleeve, 2... Magnet roll, 4
...Toner powder, 10...One-way clutch.

Claims (1)

[Claims] 1. A toner supply means integrally comprising a driving means, a toner carrying means that rotates while carrying toner, and a one-way clutch provided coaxially with the toner carrying means, and a toner carrier that receives toner from the toner supply means; a transfer means that transports the toner carrier while bringing it into contact with the toner on the toner carrier;
A developing device comprising driving force transmitting means for interlocking the toner carrying means and the transporting means and transmitting the driving force of the driving means to at least one of them.