JPH01136574A - Frictional electrification device - Google Patents

Abstract

PURPOSE:To reduce the size of the title device and improve its efficiency, by fixing a conductive member to a charging member and grounding the conductive member. CONSTITUTION:In an electronic copier, many small holes 2 are made through a hollow tube 1 in which toner 3 is stored. Fibers 5 to be charged are planted around the tube 1, than they are rotated in the direction of an arrow 4. A charging member 6 are arranged around the fibers 5 so as to charge the fibers 5 electrostatically through friction contact between them. Consequently, toner 3 in the tube 1 is adhered through the small holes 2 to the fibers 5, then it is adhered to a mesh 9 surrounding a roll 7 and moved to an electrostatic latent image on the surface of a photo-sensitive body 12, thereafter the electrostatic latent image is developed. When differential potential between the fibers 5 and the charging member 6 exceeds over a threshold, voltage leaks to a conductive member 6' and grounded. Consequently, toner can be carried efficiently.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a triboelectric charging device.

(Prior art) The use of electrostatically charged members has traditionally been used in electrophotography, electrostatic recording devices, electrostatic recording devices, electrostatic coating devices, electrostatic spraying devices, electrostatic power generation devices, electrostatic It is used in many fields such as sorting devices and ion generators.

In devices that use electrostatic charging, corona discharge (electron avalanche) is often used as a method of statically charging the charged member. This method is also often used because it has the advantage of not requiring a high-voltage power supply and therefore being less dangerous.

(Problems with the Prior Art) However, in many conventional methods of charging using frictional charging, an electric double layer is formed near the contact surface by bringing the charged member and the charging member into contact and friction. In such a device, when charging progresses considerably and the potential difference between the charged member and the charged member increases to a certain dark value or more, the charging stops, even if it is less than the saturation charge inherent to the charged member. A phenomenon occurs in which a discharge phenomenon occurs between the member and the charged member, and the charged charge disappears due to the so-called double layer separation phenomenon. It has been difficult to charge a charge close to the saturation charge amount.

(Means and effects for solving the problem) The present invention solves the above problem, and prevents the electric potential difference between the charged member and the charged member from increasing and causing discharge between the two. The purpose of this device is to charge the charged member with as much static electricity as possible, and to charge the charged member as close to the inherent saturated charge amount as possible. A conductive member is attached and grounded, and this configuration prevents the charge of the charging member from leaking when the potential difference between the charged member and the charged member attempts to reach the dark value or more. As a result, the potential difference between the charged member and the conductive member is reduced, and the charged member is charged with more static electricity.

(Example) The present invention will be described in detail below based on an example shown in the drawings.

FIG. 1 is a conceptual side view of an electrophotographic copying machine equipped with a developing device according to the present invention, in which a hollow cylinder 1 is provided with a number of small holes 2, and a toner 3 is stored in the cylinder 1. Further, a fiber hair body 5 for charging is implanted around the cylinder 1 and rotated in the direction of arrow 4, while a charging member 6 is installed around the fiber hair body 5 for charging. is arranged, and the fiber hair body 5 to be charged is charged with static electricity by contact friction between the fiber hair body 5 to be charged and the charging member 6, and thereby the toner 3 in the cylinder 1 is transferred from the small hole 2 to the charged body. After adhering the toner to the fiber capillary body 5, the toner is uniformly adhered to a mesh 9 rotating around the roll 7 in the direction of an arrow 8, and the toner is transferred to the photoreceptor 12 by the potential difference between the mesh 9 and the photoreceptor 12. This electrophotographic copying machine has a structure in which an electrostatic latent image previously formed on the surface is transferred and developed. Note that 12 and 13 in the figure are parts for adjusting the potential difference between the photoreceptor, the roll 7, and the mesh 9, respectively.

With the above-mentioned configuration, in the charging device of this copying machine, static electricity of different polarity is accumulated on the surfaces of the fiber fiber body 5 to be charged and the charging member 6, and the potential difference between the two gradually increases due to friction. However, when the potential difference between the fiber hair body 5, which is the member to be charged, and the charging member 6 becomes higher than the dark value, the electric charge of the fiber hair body 5 to be charged increases as described above. Since a discharge occurs between the conductive member 6 and the charged fiber body 5, the electric charge on the charged fiber body 5 is attenuated. The resistance value of the conductive member 6 is lower than the above voltage so that the electric charge accumulated on the charged member will leak to the conductive member 6' attached to the back side of the charging member 6 against the resistance of the charging member 6 and be discharged to the ground. It is designed and constructed in such a way that it leaks into the conductive member.

With such a configuration, when the potential difference between the conductive fiber hair body 5 and the charging member 6 exceeds a predetermined design value, the electric charge accumulated in the charging member is transferred to the conductive member 6 against the resistance value.
', and therefore more static electricity is accumulated in the fibrous body 5, which is the member to be charged, and the amount of static electricity is increased as much as possible to the inherent saturated charge of the fibrous body 5 to be charged. Similar charges will be accumulated.

(Effects of the Invention) The present invention is a device for charging by friction between a charged member and a charging member as described above, in which a conductive member is attached to the charging member and this is grounded. If the resistance value between the charging member and the conductive member is appropriately designed, the static electricity accumulated on the surface of the charging member will be leaked before the potential difference between the charged member and the charging member becomes higher than the discharge darkness value. Therefore, the charge accumulated in the charged member is not discharged to the charging member, and more static electricity can be accumulated in the charged member, which is close to the saturation charge amount specific to the charged member.

As a result, in carrying the toner in the above embodiment, the charged fiber body 5 can carry the toner more efficiently, and in addition to other devices such as an electrostatic storage device, an electrostatic sorting device, an electrostatic sorting device, etc. In any of the devices, a large amount of static electricity is accumulated in the charged member, so there are effects such as the ability to produce more effects with a smaller charged member.

FIG. 2 is a drawing similar to FIG. 1 showing another embodiment,
Unlike the example shown in FIG. 1, this is an example in which the toner is stored in a hopper 15 instead of in the cylinder 1, and is applied to the fiber body 5 to be charged by a toner roll 16. Although it is similar to the electrophotographic copying machine shown in FIG. More charges are accumulated in the charging fiber 5, thereby increasing the efficiency of the charging fiber and improving the uniformity of toner adhering thereto.

In addition to the above-mentioned embodiments, the present invention also includes the following: by charging a charged member with more charge using frictional charging,
It is expected that the efficiency of the charged member will be further improved.

[Brief explanation of the drawing]

FIG. 1 is a conceptual side view of a copying machine using a frictional charging device embodying the present invention, and FIG. 2 is a diagram similar to FIG. 1 of another copying machine using the same device.

Claims (1)

[Claims] A frictional charging device that charges a charged member with static electricity by contact friction between the charged member and the charging member, characterized in that a conductive member is attached to the charging member and this is grounded.