| 摘要 |
An optical lens device is constituted by a condensing lens in which a first lens (10) that has a positive focal length and a second lens (20) that has a negative focal length are aligned on an optical axis and disposed so as to be laminated. To suppress changes in shape of the first lens (10) accompanying changes in temperature, a glass member (19), which has a coefficient of linear expansion lower than a lens part (16) and an edge part (18), is provided in the first lens (10). The second lens (20) is used to correct the positive focal length arising in the first lens (10) alone during changes in temperature by being combined with the first lens (10). Changes in the shape of the first lens (10) are suppressed by the glass member (19), which has a small coefficient of linear expansion, and the portion that cannot be corrected by the second lens (20) is adjusted. |
