JPH0282275A - Developing device - Google Patents

Abstract

PURPOSE:To set a blade gap and a developing gap at an optimum value by providing a first ring member regulating the position of a thickness regulating member on the developer carrying area of a carrier roll and a second ring member regulating a distance between a photosensitive drum and the carrier roll on the photosensitive drum. CONSTITUTION:The photosensitive drum 1 and the carrier roll 2 are set by making the ring member 10a abut on the ring member 11a and making the ring member 10b abut on the ring member 11b. Since the ring members 10a and 10b are formed so that they may protrude from the outer circumferential surface of the carrier roll 2 as much as Ga and the ring members 11a and 11b are formed so that they may protrude from the outer circumferential surface of the photosensitive drum 1 as much as [Gb-Ga], the distance between them is made Gb being the optimum developing gap. On the other hand, a blade 5 is fixed to a hopper 3 while making it abut on the ring members 10a and 10b. Then, since the ring members 10a and 10b are made to protrude from the outer circumferential surface of the carrier roll 2 as much as Ga, the distance between them is made Ga being the optimum blade gap. Thus, both of the blade gap and the developing gap can be easily set at the optimum value.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is used in an electrostatic recording device such as an electronic copying machine, for example, to record an electrostatic latent image formed on the photosensitive surface of a photoreceptor. The present invention relates to a developing device for developing.

(Prior Art) In a developing device in an electrostatic recording device, when a developer such as toner is applied to the photosensitive surface of the photosensitive drum on which an electrostatic latent image is formed, it is generally done in parallel to the photosensitive drum. A carrier roll is provided, a magnetic brush is formed on the carrier roll, and the magnetic brush is brought into contact with the photosensitive drum.

4 and 5 are diagrams showing an example of the configuration of the above-mentioned developing device, and 3f! 4 is a top view, and FIG. 5 is a sectional view taken along the line A-A in FIG. 4. In the figure, 1 is a photosensitive drum, and a sleeve 2a is provided in parallel to this.

A magnet body 2b is provided inside the sleeve 2a, and the carrier roll 2 is formed by the sleeve 2a and the magnet body 2b. Reference numeral 3 denotes a hopper, in which toner 4 as a developer is stored. And the sleeve 2a
is located at the opening of the hopper 3 with a part of it in contact with the toner 4 in the hopper 3. A blade 5 serves as a thickness regulating member, and when the carrier roll 2 is rotated in the direction of arrow A in the figure, it is attached to the sleeve 2a by the magnetic force of the magnet 2b, and as the carrier roll 2 rotates, it is attached to the sleeve 2a. This is to keep the amount of toner 4 that is moved and guided to the outside of the hopper 3 constant.

By the way, in order to perform development with good image quality in the developing device configured as described above, the separation distance (doctor gap) Ga between the carrier roll 2 and the blade 5, and the photoreceptor drum 1 must be adjusted.
It is necessary to accurately set the separation distance (developing gap) Gb from the carrier roll 2. This is because if the doctor gap Ga is larger than the development gap Gb, the amount of toner 4 guided to the outside of the hopper 3 will be larger than the amount of developer that can pass through the development gap Gb. Toner 4 in the upstream part of the development area
It clumps up. This not only causes deterioration in image quality but also causes the toner 4 to scatter. Furthermore, if the doctor gap Ga is extremely small compared to the development gap Gb, the toner 4 will not come into sufficient contact with the photoreceptor drum 1, making it impossible to perform development reliably.

Conventionally, as shown in FIGS. 4 and 5, when the outer diameter of the carrier roll 2 is calculated and the optimum developing gap is Gb, a ring member 6a having an outer diameter of [D+2Gbl] is used.
, 6b are provided at both ends of the carrier roll 2, and these ring members 6a, 6b are brought into contact with the photosensitive drum 1. Thereby, the separation distance between the photosensitive drum 1 and the carrier roll 2 can be easily set to Gb.

Then, the blade 5 is positioned using a jig or the like so as to have an optimum doctor gap Ga, and is fixed to the hopper 3.

However, in such a conventional developing device, the developing gap Gb can be easily set to an optimal value because it is sufficient to simply bring the ring members 6a and 6b into contact with the photosensitive drum 1. However, since the blade gap Ga is positioned and installed using a jig, work efficiency is low and errors are likely to occur during installation.

Furthermore, due to the reasons mentioned above, errors may occur during installation.
Problems such as image quality deterioration and toner 4 scattering occur.

(Problems to be Solved by the Invention) As mentioned above, in conventional developing devices, the blade is attached to the hopper while being positioned using a jig, etc., which results in poor work efficiency and Errors tend to occur, and the optimum blade gap cannot be obtained, resulting in deterioration of image quality and toner scattering.

Therefore, an object of the present invention is to provide a developing device that can easily set both the blade gap and the developing gap to optimal values, and can perform optimal development without causing image quality deterioration. shall be.

[Structure of the Invention] (Means for Solving the Problems) The present invention involves bringing a developer carried on a carrier roll with its thickness regulated to a constant thickness by a thickness regulating member into contact with a photoreceptor drum, In a developing device that develops an electrostatic latent image formed on a photosensitive surface of a body drum, a developer-free IL1 holding area of the carrier roll is formed to protrude from its outer circumferential surface, and the thickness amount regulating member comes into contact with the developing device. a first ring member for controlling the position of the thickness regulating member with respect to the carrier roll; and a first ring member formed protrudingly on the photoreceptor drum at a position opposite to the first ring member and abutting the first ring member. A second ring member is provided in contact with the photoreceptor drum to regulate the separation distance between the photoreceptor drum and the carrier roll.

(Function) By taking such measures, if the protruding thickness of the first ring member from the outer circumferential surface of the carrier roll is set to the optimum value of the separation distance between the carrier roll and the thickness regulating member. ,
During assembly, the distance between the carrier roll and the thickness regulating member can be optimally set by simply bringing the thickness regulating member into contact with the first ring member.

Further, the protrusion thickness of the second ring member from the outer peripheral surface of the photoreceptor drum is set to a value obtained by subtracting the protrusion thickness of the first ring member from the optimal value of the separation distance between the photoreceptor drum and the carrier roll. If this is done, the distance between the photosensitive drum and the carrier roll can be optimally set by simply bringing the first ring member and the second ring member into contact during assembly.

(Example) Hereinafter, a developing device according to an example of the present invention will be described with reference to the drawings.

1 to 3 are diagrams showing the configuration of the developing device,
1 is a perspective view, FIG. 2 is a top view, and FIG. 3 is a sectional view taken along the line A--A in FIG. 2. Note that the same parts as in FIGS. 4 and 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

Here, the features of this developing device are that the optimum blade gap is Ga, the optimum development gap is Gb, the outer diameter of the photoreceptor drum 1 is Dl, and the outer diameter of the carrier roll 2 is Dl.
Then, the first ring member 10a has an outer diameter of [Dl +20a].

10b are provided at both ends of the carrier roll 2. Also, [D
l +2 (G a-G b) ] Null outer diameter t6
182 ring members 11a and llb are provided on the carrier roll 2 of the photoreceptor drum 1, and the first ring member 10a,
Provided at a position corresponding to IQb.

Therefore, in the developing device configured as described above, when assembling the developing device, the photosensitive drum 1 and the carrier roll 2 are
The positioning can be performed by bringing the first ring member 10a and the second ring member 11a1 and the first ring member l10b and the second ring member 11b into contact with each other, respectively. Here, the first ring member 10a, I
Qb protrudes from the outer peripheral surface of the carrier roll 2 by Ga, and the second ring members 11a, 1lb protrude from the outer peripheral surface of the photoreceptor drum 1 by [Gb-Coal, so that the photoreceptor drum 1 and the carrier The distance from the body roll 2 is Gb, which is the optimum development gap.

On the other hand, when attaching the blade 5, the blade 5 is attached to the first ring members 10a and 1 provided at both ends of the carrier roll 2.
This is done by fixing it to the hopper 3 while contacting the hopper 0b. Here, the first ring member 10a
, 10b protrudes from the outer peripheral surface of the carrier roll 2 by Ga, so that the carrier roll 2 and the blade 5
The separation distance from the blade is Ga, which is the optimum blade gap.

As described above, according to this embodiment, both the setting of the blade gap Ga and the setting of the developing gap Gb can be done by simply bringing predetermined members into contact with each other, and there is no need to use a jig or the like, so that the positioning Processing is very simple. Therefore, errors in mounting are unlikely to occur, optimal development can be performed without deterioration of image quality, and scattering of the toner 4 can also be prevented.

Further, this developing device includes a blade 5 and a first ring member 10.
a, 10b, first ring members 10a, 10b and second ring member 11a.

Since the blades 11b are in contact with each other, the blade gap and the developing gap can be kept constant to some extent even if the rotation of the photosensitive drum 1 or the carrier roll 2 is unstable. Furthermore, the blade 5 is attached to the first ring member 10a.

10b, and the second ring members 11a, l
lb is the first ring member 10a.

10b, the blade gap G can be maintained even if the rotation of the photoreceptor drum 1 or carrier roll 2 is unstable.
Fluctuations in a and the development gap Gb can be more reliably prevented.

Note that the present invention is not limited to the above embodiments.
For example, in the above embodiment, the ring members are provided at both ends of the photoreceptor drum and the carrier roll, but they may be provided anywhere other than the development area.

Further, the ring member may be formed integrally with the photoreceptor drum and the carrier roll, or may be attached separately. Furthermore, the ring member does not have to be provided on the circumferential surface of the photoreceptor drum and carrier roll, but may be provided on the rotation axis of the photoreceptor drum or the rotation axis of the carrier roll. In addition, various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the present invention, the developer carried on the carrier roll and regulated to have a constant thickness by the thickness regulating member is brought into contact with the photoreceptor drum, and the developer is formed on the photoreceptor surface of the photoreceptor drum. In a developing device for developing an electrostatic latent image, the thickness regulating member is formed in a developer non-carrying area of the carrier roll to protrude from its outer circumferential surface, and is brought into contact with the thickness regulating member to adjust the thickness of the carrier roll. a first ring member that regulates the position of the regulating member; and a first ring member that is formed protrudingly on the photoreceptor drum at a position opposite to the first ring member, and is in contact with the first ring member to prevent the photoreceptor drum and the support member from being connected to each other. Since a second ring member is provided to regulate the separation distance from the roll, it is possible to easily set both the blade gap and the developing gap to the optimum value without causing image quality deterioration. development can be performed.

[Brief explanation of the drawing]

1 to 3 are diagrams showing the configuration of a developing device according to an embodiment of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a top view, and FIG. 3 is a B in FIG. -B sectional view, FIG. 4, and FIG. 5 are diagrams each explaining the conventional technology. 1... Photoreceptor drum, 2... Carrier roll, 4...
- Toner 10a, 10b...first ring member, 1
1a, llb... second ring member. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A photoreceptor drum on which an electrostatic latent image is formed on the photoreceptor surface, a carrier roll provided parallel to the photoreceptor drum and supporting the developer on its outer peripheral surface, and a developer carried on the carrier roll. and a thickness amount regulating member for regulating the thickness of the developer carried on the carrier roll, the developer carried on the carrier roll is brought into contact with the photoreceptor drum, and the static electricity formed on the photoreceptor surface of the photoreceptor drum is In a developing device for developing an electro-latent image, the thickness regulating member is formed in a developer non-carrying area of the carrier roll to protrude from its outer peripheral surface, and the thickness regulating member is brought into contact with the carrier roll. a first ring member for regulating the position of the photoreceptor drum; and a first ring member formed protrudingly on the photoreceptor drum at a position opposite to the first ring member, and contacting the first ring member to prevent the photoreceptor drum from moving between the support roll and the photoreceptor drum. A developing device comprising: a second ring member for regulating a separation distance.