Multi-beam light source, method for manufacturing the same, light scanning unit using the same, and image forming apparatus using the same

A method for manufacturing a multi-beam light source including:

• an optical fiber array in which a plurality of optical fibers are arrayed or a semiconductor laser array in which a plurality of semiconductor lasers are arrayed;
• and
• a light guide array having a plurality of light guide patterns which are to be connected with exit surfaces of the optical fiber array or the semiconductor laser array so that a plurality of beams emitted from the optical fiber array or the semiconductor laser array are guided by the light guide patterns;
• wherein:
• an array pitch P2 of entrance surfaces of the light guide patterns is 1/N time as small as an array pitch P1 of exit surfaces of the optical fiber array or the semiconductor laser array;
• the number of the light guide patterns is N or more times as large as the number of the optical fibers or the semiconductor lasers (providing N is an integer not smaller than 2);
• and
• the method comprises the steps of:
• temporarily connecting exit surfaces of the plurality of optical fibers or the plurality of semiconductor lasers with entrance surfaces of a plurality of the light guide patterns opposed thereto;
• transmitting light from the plurality of optical fibers or the plurality of semiconductor lasers to the light guide patterns connected therewith in the state where the optical fibers or the semiconductor lasers have been temporarily connected, so as to examine existence of defects in the light guide patterns;
• and
• removing the exit surfaces of the optical fibers or the semiconductor lasers from light guide patterns having defects proved by the examination step, and permanently connecting the exit surfaces of the optical fibers or the semiconductor lasers to the other light guide patterns.

A method for manufacturing a multi-beam light source including:

• an optical fiber array in which a plurality of optical fibers are arrayed or a semiconductor laser array in which a plurality of semiconductor lasers are arrayed;
• and
• a light guide array having a plurality of light guide patterns which are to be connected with exit surfaces of the optical fiber array or the semiconductor laser array so that a plurality of beams emitted from the optical fiber array or the semiconductor laser array are guided by the light guide patterns;
• wherein:
• an array pitch P2 of entrance surfaces of the light guide patterns is 1/N time as small as an array pitch P1 of exit surfaces of the optical fiber array or the semiconductor laser array;
• the number of the light guide patterns is N or more times as large as the number of the optical fibers or the semiconductor lasers (providing N is an integer not smaller than 2);
• and
• the method comprises:
• a first temporary connection step of temporarily connecting exit surfaces of the plurality of optical fibers or the plurality of semiconductor lasers with entrance surfaces of a plurality of the light guide patterns opposed thereto;
• a first examination step of transmitting light from the plurality of optical fibers or the plurality of semiconductor lasers to the light guide patterns connected therewith in the state where the optical fibers or the semiconductor lasers have been temporarily connected in the first temporary connection step, so as to examine light transmission rates of the light guide patterns;
• a second temporary connection step of removing the exit surfaces of the plurality of optical fibers or the plurality of semiconductor lasers from the light guide patterns connected in the first temporary connection step, and temporarily connecting the exit surfaces of the plurality of optical fibers or the plurality of semiconductor lasers to entrance surfaces of the other light guide patterns which have not been examined;
• a second examination step of transmitting light from the plurality of optical fibers or the plurality of semiconductor lasers to the light guide patterns connected therewith in the state where the optical fibers or the semiconductor lasers have been temporarily connected in the second temporary connection step, so as to examine light transmission rates of the light guide patterns;
• and
• a permanent connection step of permanently connecting the optical fibers or the semiconductor lasers to the light guide patterns by a combination of the optical fibers or the semiconductor lasers and the light guide patterns proved to obtain higher light transmission rates in the first examination step and the second examination step.