| 摘要 |
PURPOSE:To lessen an SPD in area, to dispense with a photometric amplifier, and to make a circuit small in scale by a method wherein an automatic focusing SPD is divided into three pieces, a central SPD is made slightly smaller than a near infrared LED image in width, and the sides of the central SPD adjacent to other SPDs are formed polygonal. CONSTITUTION:An automatic focusing silicon photodiode(SPD) is divided into three pieces, a central SPD is made slightly smaller than a near infrared LED image in width, and the sides of the central SPD adjacent to other SPDs are formed polygonal. Near infrared rays incident on a subject from a camera body side are reflected from it and focused into a near infrared LED image 5 on SPDs 1, 2, and 3 arranged on a camera body separate from each other by the length of a base line. For instance, even if the near infrared LED image 5 is shifted and focused as a near infrared LED image 5a, the LED image is projected on the SPD 2 nearly half as much in light volume and the traveling distance of the near infrared LED image 5 on one of the SPDs becomes longer as compared with a conventional one, but the SPDs 1-3 can be lessened in area as a whole. |
