JPH0223380A - Nonmagnetic single-component developing device - Google Patents

Abstract

PURPOSE:To prevent the circumference of the developing device from being contaminated owing to the scattering of toner powder by providing a toner roll formed by solidifying toner powder, an energizing means which presses the toner roll against the surface of an image carrier in contact, a rotary driving means, and a polishing means which contacts the surface of the rotating toner roll. CONSTITUTION:The toner roll 30 which is formed by solidifying the toner powder is rotated positively around the shaft 30a of the driving means 32 by the means 32 and contacts the polishing means 36 and the surface is ground into powder, which is charged electrostatically by friction. The charged toner powder sticks on the surface of the toner roll 30 in a thin film shape and is moved onto the surface of a rotating image carrier 1 by contacting the roll 30, thereby visualizing a latent image formed there. Thus, the toner roll 30 is made into powder by a necessary among at a time and transferred to the surface of the carrier 1. Consequently, there is no excessive toner powder present nearby the developing device and the environmental contamination due to the scattering of toner is prevented.

Description

[Detailed Description of the Invention] [Summary] Regarding developing devices used in electrophotographic devices, especially regarding the configuration of a new developing device of the type that uses non-magnetic single-component toner, it is necessary to avoid parts that are easily clogged and The purpose is to provide a new developing device that does not use powdered toner, which is easily damaged, by supplying non-magnetic monocomponent toner powder to the surface of the image carrier.
A developing device for visualizing a latent image formed on the surface of the image carrier, comprising: a toner roll in which the toner powder is solidified; and a biasing means for bringing the toner roll into pressure contact with the surface of the image carrier.
The toner roll is configured to include a driving means for actively rotating the toner roll, and a polishing means for contacting the surface of the rotating toner roll.

[Industrial application field]

The present invention relates to a developing device used in a recording device that uses toner, such as an electrophotographic device, and particularly to a new type of developing device that uses non-magnetic single-component toner.

[Conventional technology]

The electronic copying apparatus has a configuration as shown in FIG. That is, a charger 2. is placed around the photosensitive drum 1 rotating in the direction of the arrow. Exposure device 3. Developing device 4. Transfer device5. A static eliminating lamp 6 and a cleaner 7 are arranged. First, the surface of the photosensitive drum 1 is given a positive charge over the entire surface by corona discharge generated from the charger 2, and the potential becomes high. Next, when light corresponding to a predetermined pattern is applied to this surface from the exposure device 3, the charge on the exposed portion decreases, the potential drops, and a latent image is formed.

When this latent image area passes through the developing device 4, positively charged toner adheres thereto, forming a toner image. On the other hand, the sheets 8 on which images are printed are fed one by one to a position where they come into contact with the toner image formed on the photosensitive drum 1 by the action of the big roller 9 and the standby roller 1O. The transfer device 5 is installed below the photosensitive drum 1 with the paper 8 in between, and is configured to apply a negative charge to the paper 8. Therefore, the toner image formed on the surface of the photosensitive drum 1 is attracted to the negative charge of the paper 8 and transferred thereto. The paper 8 carrying the toner image is transferred to a fixing device 11
The toner image is fixed on the paper 8 by heat and pressure. The surface of the photosensitive drum 10, on which the toner has been transferred to the paper 8, is completely neutralized by the neutralizing lamp 6, and the remaining toner is cleaned by the cleaner to return to the initial state, and the above-described cycle is repeated again.

A conventionally used developing device 4 is as shown in FIG. 5, and includes a developing roller 14 installed so as to be in contact with the surface of the photosensitive drum 1, and a sponge roller 15 pressed against the developing roller 14. It is installed in a container 18 containing powdered toner 16. When the toner 16 being agitated by the agitator 19 is rubbed onto the surface of the developing roller 14 via the toner supply roller 15 made of a soft sponge or fur brush, the toner is positively charged on the surface of the developing roller 14. It adheres to the skin in a thin layer. This toner layer is further charged by being rubbed by the blade 20 and at the same time adjusted to have a uniform thickness. The toner is then transferred to the surface of the photosensitive drum 10 as the developing roller 14 rotates. In order to facilitate the transfer of toner between the rollers, the rollers are configured to have different potentials between the rollers.

[Problem to be solved by the invention]

Since these conventional developing devices use powdered toner, the sponge and fur brush of the toner supply roller are easily clogged, and it is difficult to refill the container with toner. Another drawback is that the toner powder scatters and contaminates hands and the surrounding environment.

The present invention solves the problems of the prior art, and provides a new developing device that eliminates parts that are prone to clogging and parts that are easily worn out, and does not use powdered toner that is likely to fly apart. With the goal.

[Means to solve the problem]

This purpose is to provide a developing device that supplies a non-magnetic monocomponent toner powder to the surface of an image carrier and visualizes a latent image formed on the surface of the carrier, which comprises: a toner roll in which the toner powder is solidified; A developing device comprising: a biasing means for pressing the toner roll into contact with the surface of the image carrier; a driving means for actively rotating the toner roll; and a polishing means for contacting the surface of the rotating toner roll. achieved.

[For production]

The toner roll is actively rotated about its axis by the driving means, and its surface is scraped and powdered by contact with the polishing means, and the powdered toner is triboelectrically charged. The charged toner powder adheres to the surface of the toner roll in a thin layer, and is further transferred to the surface of the rotating image carrier in contact with the roll, thereby visualizing the latent image formed thereon.

Since the toner roll is powdered in the required amount and transferred onto the surface of the carrier, there is no excess toner powder in the vicinity of the developing device, and environmental contamination due to toner scattering is prevented. In addition, parts such as a toner supply roller such as a sponge or fur brush that easily gets clogged and a developing roller that easily wears out can be omitted, so that the structure of the developing device is simplified and maintenance is also facilitated.

Hereinafter, the present invention will be explained in more detail based on preferred embodiments shown in the drawings.

〔Example〕

FIG. 1 is a side view showing the structure of a first embodiment of a developing device according to the present invention, which is used in place of the developing device 40 in FIG. 4 described above.

Conventional toner has been in the form of powder, but in the present invention, the toner is formed into a roll around the shaft 30a by compacting the powder toner or adhering it to each other via a suitable binder. I am using Roll 30. The toner roll 30 as a whole is adjusted to have a volume resistivity of about 10 4 to 10 12 Ω·cm. The toner roll 30 is held in a case 31 having a U-shaped support portion 31a that receives the shaft 30a, and is disposed in contact with the surface of the photosensitive drum 1 that forms the image bearing surface in the width direction. .

A drive roller 32 is installed behind the toner roll 30, and is actively rotated at a predetermined rotational speed in the direction of the arrow by means not shown while contacting the surface of the toner roll 300. This drive roller 32 is attached to the other end of a link 34 whose one end is pivotally supported by a pin 33. The link 34 is biased counterclockwise in the figure by a coil spring 35, so that the drive roller 3
2 is in contact with the toner roll 30 with a predetermined pressure so as to push it forward.

A blade 36 is installed above the toner roll 30,
The biasing force of the spring 37 causes its tip to contact the surface of the toner roll 30 with a predetermined pressure.

When the toner roll 30 is rotationally driven by the drive roller 32, the blade 36 gradually scrapes off the surface of the toner roll 30, pulverizes the toner, and frictionally charges the powdered toner, forming a thin layer on the roll 300.
It is attached to the surface and conveyed toward the photosensitive drum l. A developing bias is applied between the photosensitive drum 1 and the toner roll 30, and as mentioned above, the toner roll 30 has a resistivity of 10 to 10 cm, so the charged toner powder is smoothly transferred to the surface of the photosensitive drum 1. The latent image carried thereon is developed and visualized. The residual toner that has not been transferred to the photosensitive drum 1 returns to the drive roller 32 side again as the toner roll 300 rotates, and is conveyed to the photosensitive drum 1 again together with the newly scraped and powdered toner.

According to this embodiment, the trouble of contaminating the surrounding area due to powder scattering due to the toner roll is reduced. Further, it is possible to omit a large container, an agitator, a toner supply roller, etc. which are required in a conventional developing device, and a simple and compact structure can be achieved.

In the example shown in FIG. 2, a vibrator 38 oriented in the longitudinal direction is added to the blade 36 having the above-described configuration, so as to apply vibrations of minute amplitude to the blade 36.

This further promotes toner powderization and triboelectric charging on the toner roll surface.

In the example shown in FIG. 3, the blade 36 as the polishing means in FIG. 1 is replaced with a rotating polishing roller 39. This polishing roller 39 is attached to the other end of a link 40 which is coaxially supported with the drive roller 32 at the tip of the arm 34, and the toner roll 30 is moved by the action of a coil spring 41 which urges the link 40 in a counterclockwise direction. pressed against the surface of

The speed of the polishing roller 39 is suitably changed by a gear 43 meshing with a gear 42 provided coaxially with the drive roller 32 (i.e., at a surface speed different from that of the toner roll).
The toner roll 300 is rotated to scrape off the surface of the toner roll 300 and turn it into powder. Thus, in this example, the toner roll and polishing roller come into more intense frictional contact, which promotes toner pulverization and increases its charging capacity.

The polishing roller is made of known resins that charge the polishing roller by friction with the toner roll, and its surface is processed to have an appropriate roughness.

〔Effect of the invention〕

As detailed above, according to the present invention, since the use of powder toner is eliminated and a solid toner roll is adopted, toner can be stored in a cartridge in the developing device, and excessive Contamination of the surrounding area due to scattering of toner powder is prevented, and toner can be replaced without getting hands dirty. Furthermore, since parts such as an agitator and a toner supply roller can be omitted, there is an advantage that the apparatus can be configured compactly.

[Brief explanation of the drawing]

1 is a side view schematically showing the configuration of a developing device according to a first embodiment of the present invention; FIG. 2 is a side view of the second embodiment; FIG. 3 is a side view of the third embodiment; FIG. 4 is a side view showing the overall structure of an electronic copying apparatus to which the present invention is applied, and FIG. 5 is a side view schematically showing the structure of a conventional developing device. l・Photosensitive drum, 30 Toner roll, 31
case, 32 drive roller, 33 pin,
34 link, 35 coil spring, 36 blade, 37 spring, 38.
Vibrator, 39 Polishing roller, 40 Link,
41.42 Gears.

Claims (1)

[Claims] 1. A developing device that supplies non-magnetic monocomponent toner powder to the surface of an image carrier (1) and visualizes a latent image formed on the surface of the carrier (1), the toner powder being solidified. a toner roll (30); urging means (31, 33, 34, 38) for pressing the toner roll into contact with the surface of the image carrier;
a driving means (for actively rotating the toner roll (30);
32; 40, 41, 42) and a rotating toner roll (
and polishing means (36, 39) in contact with the surface of the non-magnetic one-component developer.