LUMINESCENT LIGHT QUANTITY CONTROL DEVICE FOR SEMICONDUCTOR LASER

• Main Authors: SENMA TOSHITAKA, TAKAHASHI MASARU, MORI GORO, YAMAMOTO MASAHIRO, MIYAJIMA MASAMI, ARAKI SHIGEYUKI, ISOBE TAKAHITO, HAYASHI TAKAMASA
• Format: Patent
• Language: English
• Published: 01.06.1992
• 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

PURPOSE:To obtain a high-quality image by changing the comparing reference voltage corresponding to the luminescent light quantity in response to the picture element density for obtaining the luminescent light quantity of a semiconductor laser optimum to each picture element density. CONSTITUTION:The picture element density data indicating the preset picture element density are inputted to a D/A converter setting circuit 23, the output value to a D/A converter 24 corresponding to the picture element density is stored in the memory device 23B of the circuit 23, when the picture element density data are inputted to the circuit 23, the address of the device 23B storing the output value corresponding to the data is selected by a picture element density data address converting device 23A, and the optimum output value is outputted to the converter 24 from the device 23B. The output value is D/A- converted by the converter 24 and inputted to a comparator 17 generating the reference voltage Vref, it is compared with the voltage VM indicating the received light intensity corresponding to the luminescence intensity from a semiconductor laser, and the obtained binary signal is fed to an up/down counter 18.