Color image forming apparatus with plural color units

An apparatus for forming color images, comprising:

• a plurality of image forming units including a developing device having a different color toner and a developing roller, and a photosensitive drum;
• a first motor for rotationally driving said photosensitive drum;
• a carriage for retaining and moving said plural image forming units;
• a second motor for driving said carriage so as to move said image forming units between an image forming position where a toner image is formed on said photosensitive drum and a waiting position one by one;
• a transfer medium for accepting each color toner image formed on said photosensitive drum so as to form a multicolor image;
• and
• said second motor also driving the developing device of the image forming unit located at said image forming position.

An apparatus for forming color images, comprising:

• a photosensitive drum for forming an electrostatic latent image;
• a plurality of developing units including a different color toner and a developing roller;
• a carriage that retains and moves said plural developing units;
• means for driving said carriage so that said plural developing units are moved between an image forming position where a toner image is formed on said photosensitive drum and a waiting position one by one, said carriage drive mechanism including a motor and a transmission;
• a transfer medium for accepting each color toner image formed on said photosensitive drum onto a transfer medium so as to form a multicolor image;
• said transmission of said carriage driving means including a worm gear, a worm wheel and a clutch disposed between said motor and said worm gear;
• and
• said plural developing units being retained removably in said carriage.

An apparatus for forming color images, comprising:

• a plurality of image forming units including a developing device having a different color toner and a developing roller, and a photosensitive drum;
• a carriage that retains and moves said plural image forming units;
• means for driving said carriage so that said plural image forming units are moved between an image forming position where a toner image is formed on said photosensitive drum and a waiting position one by one, said carriage drive mechanism including a motor and a transmission;
• a transfer medium for accepting each color toner image formed on said photosensitive drum so as to form a multicolor image;
• said transmission of said carriage driving means including a worm gear, a worm wheel and a clutch disposed between said motor and said worm gear;
• and
• said plural image forming units being retained removably in said carriage.