Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
289 words
An image forming apparatus, comprising: a movable image bearing member; means for forming an electrostatic latent image on said image bearing member; developing means for developing the latent image, said developing means including, a developer carrying member rotatable in a first direction to carry a developer to a developing zone to develop the electrostatic latent image and is rotatable in a second direction opposite to the first direction for a predetermined period when it does not develop the latent image; a magnet stationarily disposed in said developer carrying member, wherein said magnet has a first magnetic pole and a second magnetic pole having the same magnetic polarity at positions downstream of the developing zone with respect to the first direction, and the first and second magnetic poles are adjacent with each other, with the second magnetic pole disposed downstream of the first magnetic pole with respect to the first direction; a container for containing the developer to be carried out of said container by rotation of the developer carrying member in the first direction, and the developer is supplied to said developer carrying member in said container at a position downstream of a position where a magnetic force is minimum between the first and second magnetic poles, with respect to the first direction; and whereby during rotation of said developer carrying member in the first direction, the developer having passed through the developing zone is removed from the developer carrying member in the magnetic field formed between the first and second magnetic poles, and during rotation of said developer carrying member in the second direction, the developer on the developer carrying member being carried toward the developing zone is removed from said developer carrying member in the magnetic field.
Claim 2
Dependent Claim
289 words
An image forming apparatus, comprising: a movable image bearing member; means for forming an electrostatic latent image on said image bearing member; developing means for developing the latent image, said developing means including, a developer carrying member rotatable in a first direction to carry a developer to a developing zone to develop the electrostatic latent image and is rotatable in a second direction opposite to the first direction for a predetermined period when it does not develop the latent image; a magnet stationarily disposed in said developer carrying member, wherein said magnet has a first magnetic pole and a second magnetic pole having the same magnetic polarity at positions downstream of the developing zone with respect to the first direction, and the first and second magnetic poles are adjacent with each other, with the second magnetic pole disposed downstream of the first magnetic pole with respect to the first direction; a container for containing the developer to be carried out of said container by rotation of the developer carrying member in the first direction, and the developer is supplied to said developer carrying member in said container at a position downstream of a position where a magnetic force is minimum between the first and second magnetic poles, with respect to the first direction; and whereby during rotation of said developer carrying member in the first direction, the developer having passed through the developing zone is removed from the developer carrying member in the magnetic field formed between the first and second magnetic poles, and during rotation of said developer carrying member in the second direction, the developer on the developer carrying member being carried toward the developing zone is removed from said developer carrying member in the magnetic field.
Claim 3
Dependent Claim
91 words
An apparatus according to Claim 1, further comprising a regulating member, faced to said developer carrying member with a gap, for regulating a layer thickness of the developer to be carried to the developing zone, wherein said magnet has a third magnetic pole upstream of said regulating member and downstream of the second magnetic pole with respect to the first direction, and a fourth magnetic pole adjacent to said third magnetic pole and downstream of said regulating member, and wherein the third and fourth magnetic poles are opposite in the polarity.
Claim 4
Dependent Claim
28 words
An apparatus according to Claim 1, wherein said container is provided with stirring means for stirring the developer removed from said developer carrying member in the magnetic field.
Claim 5
Dependent Claim
33 words
An apparatus according to claim 1 or 2, wherein said developer carrying member rotates in the second direction for a predetermined period of time after completion of development of the electrostatic latent image.
Claim 6
Dependent Claim
31 words
An apparatus according to claim 4, wherein said developer carrying member rotates in the second direction for a second predetermined of time before start of formation of the electrostatic latent image.
Claim 7
Dependent Claim
32 words
An apparatus according to claim 5, wherein said developer carrying member rotates in the second direction for a second predetermined period of time before start of movement of said image bearing member.
Claim 8
Independent Claim
42 words
An apparatus according to any preceding claim, further comprising a bias voltage source for applying to said developer carrying member a bias voltage for forming an alternating electric field in the developing zone at least during development operation of the latent image.
Claim 9
Dependent Claim
37 words
An apparatus according to claim 7, further comprising means for stopping application of the bias voltage to said developer carrying member during a period of non-developing-operation containing rotation of said developer carrying member in the second direction.
Claim 10
Independent Claim
31 words
An apparatus according to any preceding claim, wherein a magnetic brush of the developer is formed and is contacted to said image bearing member in the developing zone during developing operation.
Claim 11
Independent Claim
46 words
An apparatus, according to any preceding claim, wherein a plurality of such developing means are provided for developing the latent images formed by said image forming means, such that when one of said developing means develops the latent image, the other developing device is not operated.