Multiimage forming apparatus

An image forming apparatus comprising:

• (a) image forming means for forming different images onto a plurality of image holding devices;
• (b) transfer means for transferring the images on said plurality of image holding devices onto a same transfer material;
• (c) control means for controlling the image forming means so as to form a mark to match the positions of said images onto the plurality of image holding devices;
• and
• (d) detecting means for detecting the recording position of said mark and correcting means for correcting a plurality of positional deviation elements among said images on the basis of a detection output of said detecting means.

An image forming apparatus comprising:

• (a) image writing means for writing registration marks at regular intervals while an image is being written onto an image holding device;
• (b) transfer means which moves so as to transfer the image and said registration marks on said image holding device at transfer positions;
• (c) detecting means for detecting the positions of said registration marks on said transfer means during the formation of the image;
• and
• (d) correcting means for correcting the position of the image on the image holding device during the image formation on the basis of a detection signal from said detecting means.

An image forming apparatus comprising:

• (a) image forming means for forming different images onto a plurality of image holding devices;
• (b) means for moving among said image holding devices a transfer material onto which the images formed on the image holding devices are transferred, a mark for position matching being formed on said moving means;
• (c) means for generating a predetermined reference signal in association with an image forming sequence of said image forming means, said generating means including means for detecting the position of said transfer material which is moved by said moving means, said detecting means generating said reference signal when the transfer material is moved to a predetermined position;
• and
• (d) means for controlling said image forming means on the basis of the result of the detection of said mark and said reference signal.

An image forming apparatus comprising:

• (a) a plurality of image forming stations which are constituted around image holding devices so as to have image forming means;
• (b) detecting means, formed by each of the image holding devices of each of the image forming stations, for detecting registration mark images corresponding to each of the image holding devices which are sequentially transferred to a conveying material or a transfer material which are conveyed adjacently to each of the image holding devices;
• and
• (c) correcting means for correcting a positional deviation of each of the image forming stations in accordance with a relative difference between an output timing of a predetermined reference signal which is generated every time in association with an image sequence of each of the image forming stations and a detection timing of each of the registration mark images which are sequentially detected by said detecting means.

An image forming apparatus comprising:

• (a) an image forming station which is constituted around each image holding device so as to have image forming means;
• (b) detecting means for detecting each of registration mark images which are formed by said image forming station and transferred to a conveying device;
• and
• (c) mark transfer means for transferring each of the registration mark images which are formed on each of the image holding devices between image transfer areas which are formed on the image holding devices and continuously transferred onto said conveying device.

An image forming apparatus comprising:

• a plurality of image forming means including a plurality of optical means for forming different images on a plurality of image holding members;
• transfer means for transferring the images on said plurality of image holding means to the same transfer material;
• detecting means for detecting a quantity corresponding to positional deviations of said images formed by said plurality of image forming means;
• and
• control means for controlling said optical means of said plurality of image forming means on the basis of the detection of said means.

An image forming apparatus comprising:

• an optical system for guiding onto a photosensitive member a bundle of light for formation of image;
• detecting means for detecting a positional deviation of an image formed on said photosensitive member;
• and
• control means for controlling said optical system on the basis of the detection of said detecting means.