PURPOSE: To hold the initial surface shape of the display element stably even when writing and erasure are performed repeatedly on the surface of the display element by using a wear-resistant transparent rubber elastic body which is stable to heat as a protection film on the surface of the display element which is written and erased thermally.
CONSTITUTION: The filmy transparent polymer rubber elastic body which has rubber elasticity at the temperature of the writing and erasure is provided as the protection layer on the surface of the display element 13 which is written and erased thermally by using a thermal head 11, etc. There are silicone rubber such as polydimethyl siloxane, ethylene-propylene rubber, ethylene-propylene- diene rubber, olefin rubber such as styrene-butadiene rubber, urethane rubber, fluororubber, etc., as the polymer rubber elastic body. Consequently, the initial surface shape of the protection layer film can be maintained even after long- period use.
YOSHINAGA KAZUO
KANEKO SHUZO
TOSHIDA YOSHI
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