Color image forming apparatus comprising separate motors for driving the image bearing member and the transfer material supporting member

A color image forming apparatus, comprising:

• an image bearing member movable along an endless path, on which color toner images are formed;
• a transfer material supporting member movable along an endless path for supporting a transfer material and conveying it to an image transfer position where the color toner images are superposedly transferred sequentially to the transfer material;
• a first driving motor for driving said image bearing member;
• a second driving motor, separately provided from said first motor, for driving said transfer material supporting member;
• means for detecting a speed of movement of a surface of the transfer material;
• means for discriminating whether a variation of the speed detected by said detecting means is within a tolerable range or not;
• and
• control means, responsive to said discriminating means, for stopping operation of a subsequent image transfer step when the variation is beyond the tolerable range, and a latent image forming and developing and transferring step is repeated.

A color image forming apparatus, comprising:

• an image bearing member movable along an endless path, on which color toner images are formed;
• a transfer material supporting member movable along an endless path for supporting a transfer material and conveying it to an image transfer position where the color toner images are superimposed and transferred sequentially to the transfer material;
• a first driving motor for driving said image bearing member;
• a second driving motor, separately provided from said first motor, for driving said transfer material supporting member;
• signal generating means for generating a signal indicative of the speed of said transfer material supporting member;
• and
• means for controlling said transfer material supporting member in accordance with the signal from said signal generating means.

A color image forming apparatus comprising:

• an image bearing member movable along an endless path, on which color toner images are formed;
• a transfer material supporting member movable along an endless path for supporting a transfer material and conveying it to an image transfer position where the color toner images are superimposed and transferred sequentially to the transfer material;
• a first driving motor for driving said image bearing member;
• and
• a second driving motor, separately provided from said first motor, for driving said transfer material supporting member;
• signal generating means for generating a signal indicative of the surface speed of the transfer material;
• and
• means for discriminating whether the surface speed of the transfer material is proper in accordance with the signal from said signal generating means to inhibit color image formation on the transfer material when said discriminating means discriminates an improper surface speed.