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US 4,903,634 AGranted
Developing device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsTaizo Ono, Yoshihiro Katayama, Hayato Kamada, Hidenori Kunishige
Life of this patent
Estimating the term…
Abstract
A developing device for developing a latent electrostatic image for an electrophotographic copying machine includes a cylindrical resilient body such as a fur brush or a roller of sponge for triboelectrically uniformly charging a single component developer of the dry type supplied from a developer storage casing and for coating the developer as a uniform thin layer on a developer carrier such as a developing roller.
Claims21
A developing device for visualizing a latent electrostatic image formed on a latent image carrier, comprising:
- a casing for containing a developer, said casing having an outlet at one end thereof;
- an endless movable developer carrier for carrying the developer thereon, said developer carrier being disposed in said casing outlet;
- means for charging the developer, said charging means comprising a cylindrical resilient body rotatably mounted in said casing in confronting relation to the developer carrier;
- means for transferring and coating the charged developer as a layer onto said developer carrier under an electric field;
- means for limiting the thickness of said layer of developer on said developer carrier to a prescribed thickness;
- and
- a swingable resilient sheet having one end fixedly mounted in said casing and the other end held in contact with the outer circumferential surface of said cylindrical resilient body, said swingable resilient sheet being vibratable under its own resiliency on rotation of said cylindrical resilient body;
- said transferring and coating means and said thickness limiting means being successively disposed in the direction in which said developer carrier moves;
- and
- said charging means, said transferring and coating means and said developer carrier being arranged such that only the developer which passes through said charging means is supplied to said developer carrier.
7 more elements
A developing device for visualizing a latent electrostatic image formed on a latent image carrier, comprising:
- a casing containing developer therein and provided with an outlet;
- an endless movable developer carrier arranged in the outlet of the casing for carrying the developer thereon;
- a rotatable cylindrical charging body arranged within the casing so that a portion of the casing surrounds part of the cylindrical charging body and adjacent the developer carrier for charging the developer and supplying charged developer adjacent the developer carrier, the developer carrier being arranged between the cylindrical charging body and the outlet of the casing, the cylindrical charging body being arranged between the developer carrier and the developer contained within the casing, the developer carrier and the cylindrical charging body being movable in a common direction at a position where the developer carrier and the cylindrical charging body are in contact, the peripheral speed of the cylindrical charging body being higher than the peripheral speed of the developer carrier, the cylindrical charging body being operative to transfer the charged developer to the developer carrier and to coat the charged developer as a layer on said developer carrier, and the part of the cylindrical resilient body which is surrounded by the casing rotating in a direction from a bottom of the casing toward the developer carrier;
- and
- means for limiting the thickness of said layer of the developer on said developer carrier to a prescribed thickness, said thickness limiting means being arranged downstream of the position where the developer is transferred from the cylindrical charging body to the developer carrier with respect to the direction in which the developer carrier moves.
2 more elements
A developing device for visualizing a latent electrostatic image formed on a latent image carrier, comprising:
- a movable endless developer carrier carrying a developer thereon, the developer carrier opposing the latent image carrier;
- a rotatable cylindrical resilient body contacting the outer circumferential surface of the developer carrier, the developer carrier and the cylindrical resilient body being movable in a common direction at a position where the developer carrier and the cylindrical resilient body are in contact, the peripheral speed of the cylindrical resilient body being higher than the peripheral speed of the developer carrier;
- means for limiting a layer of the developer to a prescribed thickness, the developer layer extending on the developer carrier in a region downstream, with respect to a direction of movement of the developer carrier, of a position where the developer carrier and the cylindrical resilient body oppose each other, and upstream of a position where the developer carrier and the latent image carrier oppose each other;
- means for supplying the developer to an outer circumferential surface of the cylindrical resilient body at a position distant from the position where the developer carrier and the cylindrical resilient body oppose each other;
- and
- a casing accommodating the developer and the supplying means, wherein a portion of the casing surrounds part of the outer circumferential surface of the cylindrical resilient body extending between the supplying means and the developer carrier and wherein the part of the cylindrical resilient body which is surrounded by the casing rotates in a direction from a bottom of the casing toward the developer carrier.
3 more elements
A developing device for visualizing a latent electrostatic image formed on a latent image carrier, comprising:
- a casing accommodating a developer, an end of the casing having an outlet;
- an endless developer carrier positioned at the outlet of the casing and carrying the developer thereon;
- a rotatable cylindrical resilient body contacting an outer circumferential surface of the developer carrier;
- means for limiting a layer of the developer to a prescribed thickness, the developer layer extending on the developer carrier in a region downstream, with respect to a direction of movement of the developer carrier, of a position where the developer carrier and the cylindrical resilient body oppose each other;
- and
- a resilient sheet extending in the casing and having first and second ends, the first end being fixed to the casing, the second end engaging the developer, the resilient sheet driving the developer toward the cylindrical resilient body.
3 more elements
A developing device for visualizing a latent electrostatic image formed on a latent carrier, comprising:
- a casing accommodating a developer, an end of the casing having an outlet;
- an endless developer carrier positioned at the outlet of the casing and carrying the developer thereon;
- a rotatable cylindrical resilient body contacting an outer circumferential surface of the developer carrier;
- and
- a resilient sheet extending in the casing and having first and second ends, the first end being fixed to the casing, the second end engaging the developer, the resilient sheet swinging in response to rotation of the cylindrical resilient body.
2 more elements
Dependencies are inferred from the claim text.