Color image formation apparatus with density measurement

• Main Authors: TOYOMURA; YUUJI, MITSUSE; TOSHIHIKO
• Format: Patent
• Language: English
• Published: 28.06.1994
• Edition: 5
• Subjects: CINEMATOGRAPHY; CORRECTION OF TYPOGRAPHICAL ERRORS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; MAGNETOGRAPHY; PERFORMING OPERATIONS; PHOTOGRAPHY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; PRINTING; SELECTIVE PRINTING MECHANISMS; STAMPS; TRANSPORTING; TYPEWRITERS

An image formation apparatus for forming a color image, having an image combining member for overlapping a plurality of different mono-color images formed by an electrophotographic process with a plurality of respective different colorants to form the color image thereon and a density measuring unit for measuring a reflective density at a desired portion of the color image, the density measuring unit having light emitting portion, such as a light emitting diodes, for emitting light toward the image combining member and a photoelectric conversion element, such as a phototransistor, for receiving and photoelectrically-converting the light reflected at the image combining member to a density signal, the plurality of colorants being divided into first and second groups, the first group of the plurality of different colorants having a higher reflectivity than the image combining member with respect to the light, a second group of the plurality of different colorants having a lower reflectivity than the image combining member comprises: a switching circuit for causing the light emitting portion to change an intensity of the light in response to an intensity control signal.