PRODUCTION OF FRESNEL LENS AND PROJECTION TYPE TELEVISION USING FRESNEL LENS OBTAINED BY THIS PRODUCTION

Title:

PRODUCTION OF FRESNEL LENS AND PROJECTION TYPE TELEVISION USING FRESNEL LENS OBTAINED BY THIS PRODUCTION

Document Type and Number:

Japanese Patent JPH085804

Kind Code:

A

Abstract:

PURPOSE: To provide a process for producing a Fresnel lens which prevents the unnecessary rays from the non-lens parts of the Fresnel lens.

CONSTITUTION: Metal molds separable to an upper mold and lower mold 9 are constituted by forming rising projecting parts composed of non-lens shape parts 9b and lens shape parts 9a of the Fresnel lens where the lens shapes of the metal molds are made discontinuous to an overhang shape with respect to the axis of the press direction of the upper mold and the lower mold 9; in addition, ruggedness is formed at the tips 9c of the projecting parts. The metal molds constituted in such a manner are used. A sheet-like material 10 previously heated to the glass transition temp. region of the material is interposed between the upper mold and the lower mold a and a pressure is applied to the heated metal molds, by which rugged grooves are formed in the non-lens parts of the resulted Fresnel lens.

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Inventors:

INAGE HISAO
TAKAGI MASAO
MURANAKA MASAYUKI
YATSUDA NORIO
WADA KIYOSHI

Application Number:

JP336795A

Publication Date:

January 12, 1996

Filing Date:

January 12, 1995

Export Citation:

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Assignee:

HITACHI LTD

International Classes:

G02B3/08; G03B21/62; (IPC1-7): G02B3/08; G03B21/62

Domestic Patent References:

JPS52145238A	1977-12-03
JPS56142501A	1981-11-06

Attorney, Agent or Firm:

Yoshiaki Numagata (1 person outside)

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