| 摘要 |
Simple, inexpensive and durable multi-element lens systems are provided. These lens systems may be optically coupled to digital image-capturing devices, such as those used in digital cameras. Some lens systems of the present invention include a glass microsphere bonded to a planar surface of a glass hemisphere. In preferred lens systems, the thickness of the glass hemisphere is selected to form an image plane for transmitted light that is tangent to the surface of the microsphere. Accordingly, in digital cameras fabricated with such lens systems, the glass microsphere can be attached directly to a digital image-capturing device. These preferred lens systems require no focusing adjustment and are suitable for applications requiring a wide field of view. In some embodiments, the glass microsphere is bonded to the glass hemisphere using a light-absorbing material in order to create an apodized pupil. Some such embodiments are fabricated with a light-absorbing material with an absorption coefficient that varies according to the wavelength of transmitted light. |
