An image forming apparatus

Claim 2

An image forming apparatus, comprising: a movable image bearing member; means for forming electrostatic latent images on said image bearing member; a plurality of developing units for developing the electrostatic latent images by developers having different colors; supporting means for supporting the plural developing units, said supporting means being rectilinearly movable along a predetermined path; driving means for driving said supporting means along the path; and developing unit moving means for moving a selected one of said developing units in a direction crossing with a direction of the rectilinear movement to a developing position.

Claim 3

An apparatus according to Claim 1, wherein said developing unit moving means includes a rack provided in said supporting means, a gear engageable with the rack and rotatable at a fixed position in association with movement of said supporting means, and a movable acting member for moving said developing unit to the developing position using rotational force of the gear.

Claim 4

An apparatus according to Claim 2, wherein in a driving force transmission path between the gear and the acting member, there is a clutch for selectively transmitting the driving force to the acting member.

Claim 5

An apparatus according to Claim 1, 2 or 3, wherein said image bearing member is in the form of a rotatable drum, and said supporting means is laterally reciprocable below said image bearing member, said apparatus further comprising image transfer means for transferring a developed image formed on said image bearing member at an image transfer position above a horizontal plane including a central axis of said image bearing member.

Claim 6

An image forming apparatus, comprising: a movable image bearing member; means for forming electrostatic latent images on said image bearing member; first and second developing units for developing the electrostatic latent images by developers having different colors; supporting means for supporting said first and second developing units, said supporting means being rectilinearly movable along a predetermined path; driving means for reciprocally moving said supporting means along the path; wherein when said supporting means is at its home position, said first developing unit is in one side of a developing position, and second developing unit is in an opposite side.

Claim 7

An image forming apparatus, comprising: a movable image bearing member; means for forming electrostatic latent images on said image bearing member; first and second developing units for developing the electrostatic latent images by developers having different colors; supporting means for supporting said first and second developing units, said supporting means being rectilinearly movable along a predetermined path; driving means for reciprocally moving said supporting means along the path; wherein when said supporting means is at its home position, said first developing unit is in one side of a developing position, and second developing unit is in an opposite side.

Claim 8

An apparatus according to Claim 5, further comprising developing unit moving means for moving selected one of the developing units to a developing position in a direction crossing with a direction of said rectilinear movement using driving force for said supporting means.

Claim 9

An apparatus according to Claim 6, wherein said developing unit moving means includes a rack provided in said supporting means, a gear engageable with the rack and rotatable at a fixed position in association with movement of said supporting means, and a movable acting member for moving said developing unit to the developing position using rotational force of the gear.

Claim 10

An apparatus according to Claim 7, wherein in a driving force transmission path between the gear and the acting member, there is a clutch for selectively transmitting the driving force to the acting member.

Claim 11

An apparatus according to Claim 5, 6, 7 or 8, wherein said image bearing member is in the form of a rotatable drum, and said supporting means is laterally reciprocable below said image bearing member, said apparatus further comprising image transfer means for transferring a developed image formed on said image bearing member at an image transfer position above a horizontal plane including a central axis of said image bearing member.

Claim 12

An image forming apparatus, comprising: a movable image bearing member; means for forming electrostatic latent images on said image bearing member; a plurality of developing units for developing the electrostatic latent images by developers having different colors, each of said developing units having a movable developer carrying member for carrying the developer to supply it to said image bearing member; supporting means for supporting said plural developing units, said supporting means being rectilinearly movable along a predetermined path; first driving means for driving said supporting means to move it along the path; second driving means for supporting the developer carrying member of each of said developing units, said second driving means including a driving motor and drive transmission means for transmitting a driving force of the driving motor to each of said developer carrying members, and being supported on said supporting means.

Claim 13

An image forming apparatus, comprising: a movable image bearing member; means for forming electrostatic latent images on said image bearing member; a plurality of developing units for developing the electrostatic latent images by developers having different colors, each of said developing units having a movable developer carrying member for carrying the developer to supply it to said image bearing member; supporting means for supporting said plural developing units, said supporting means being rectilinearly movable along a predetermined path; first driving means for driving said supporting means to move it along the path; second driving means for supporting the developer carrying member of each of said developing units, said second driving means including a driving motor and drive transmission means for transmitting a driving force of the driving motor to each of said developer carrying members, and being supported on said supporting means.

Claim 14

An apparatus according to Claim 10, further comprising developing unit moving means for moving selected one of said developing units to a developing position in a direction crossing with a direction of the rectilinear movement using moving force for said supporting means.

Claim 15

An apparatus according to Claim 11, wherein each of said developing units is supported on said supporting means for swinging movement about an axis, and is moved to a developing position by said developing unit moving means, wherein the driving force transmitting means of said second driving means includes a gear train coaxial with the axis.

Claim 16

An apparatus according to Claim 12, wherein said developing unit moving means includes a rack provided in said supporting means, a second gear engageable with the rack and rotatable at a fixed position in association with movement of said supporting means, and a movable acting member for moving said developing unit to the developing position using rotational force of the gear.

Claim 17

An apparatus according to Claim 13, wherein in a driving force transmission path between the second gear and the acting member, there is a clutch for selectively transmitting the driving force to the acting member.

Claim 18

An apparatus according to Claim 10, 11, 12, 13 or 14, wherein said image bearing member is in the form of a rotatable drum, and said supporting means is laterally reciprocable below said image bearing member, said apparatus further comprising image transfer means for transferring a developed image formed on said image bearing member at an image transfer position above a horizontal plane including a central axis of said image bearing member.

Claim 19

Apparatus, as claimed in claim 1, wherein said developing unit moving means includes means for moving said supporting means.