Abstract: A backrest adjusting device for office chairs comprising: a seat portion having a seat cushion and a stand for supporting the seat cushion; a back having a frame, a back cushion fixed on the surface of the frame, a connecting member for connecting the bottom of the back to a rear side of the seat portion, a hollow containing space formed at the middle section of the back, an n-shaped member being disposed in the containing space and extended backward; and a first attaching device installed on the n-shaped member of the containing space, thereby achieving the adjustment of the three-dimensional space of position, longitudinal buffer and angular rotation. Moreover, the back further includes a support member disposed at the top of the back, and a second attaching device installed on the support member and having a structure identical to the first attaching device. Meanwhile, the first attaching device has an attaching body made in compliance with the shape of a human waist to form a backrest bump.

Abstract: This invention relates to a method for manufacturing optical fiber light guide badges, which comprises four steps: making a mold, making a badge, connecting optical fibers with the badge, and producing a convex mirror effect on an optical fiber light spot. The foregoing structure can achieve the effects of providing an artistic look to the badge and saving costs.