| 摘要 |
PURPOSE:To prevent the generation of stress without direct pressing of lens faces and to prevent the deterioration owing to the accumulation of the internal strain of plastic lenses by forming flanges and screws in one body to the circumferential edges of the plastic lenses, and screwing and fixing the same to the screws provided to a lens-barrel under specified pressure. CONSTITUTION:Flanges 23, 33, 43, 53 are formed on one side of the respective circumferential edges 22, 32, 42, 52 of plastic lenses 2, 3, 4, 5 and screws 24, 34, 44, 54 are formed to the circumferential edges in one body with the lenses. A lens-barrel 1 is provided with the screws and flange receiving parts corresponding to the respective lenses and the respective lenses are screwed and fixed to the barrel 1 under specified force. The accumulation of internal strain owing to the generation of stress and the possibility of the deterioration in performance owing to a change with time or temp. or the like are thus eliminated without direct pressing of the lens faces. The need for parts such as spacers is eliminated, whereby the number of assembling stages and the cost are reduced. |
