| 摘要 |
PROBLEM TO BE SOLVED: To detect fingerprints stably with high sensitivity by shaping a columnar elastic body larger in height than in breadth in section in a source, a drain direction. SOLUTION: In order to measure an output of a tactile sensor transistor with the use of a source follower circuit, a differential output to an output of a source follower circuit of an adjacent MOSFET is measured which has a low output resistance and is little influenced by a characteristic change of a transistor because of a temperature change, thereby negating the influence of the temperature change. As a result, only a change because of unevenness of a fingerprint is taken out. A columnar elastic body 6 constituting a sensor part is formed of, e.g. photosensitive silicone resin in a rectangular cross section. For example, when a distance between a source area 1 and a drain area 4 is 5μm, the cross section of the columnar elastic body 6 can be selected to have 7μm breadth and 8μm height. When a force is applied from above from a rising part of the fingerprint, the columnar elastic body 6 shrinks in a longitudinal direction and at the same time expands in a lateral direction. A deformation in the longitudinal direction can be facilitated, thereby improving sensitivity of a sensor.
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