JPS565502A - Optical path converting device - Google Patents

Optical path converting device

Info

Publication number
JPS565502A
JPS565502A JP8048779A JP8048779A JPS565502A JP S565502 A JPS565502 A JP S565502A JP 8048779 A JP8048779 A JP 8048779A JP 8048779 A JP8048779 A JP 8048779A JP S565502 A JPS565502 A JP S565502A
Authority
JP
Japan
Prior art keywords
transparent plate
notches
periphery
video light
constitution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP8048779A
Other languages
Japanese (ja)
Other versions
JPS633282B2 (en
Inventor
Toshiro Watanabe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sony Corp
Original Assignee
Sony Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sony Corp filed Critical Sony Corp
Priority to JP8048779A priority Critical patent/JPS565502A/en
Publication of JPS565502A publication Critical patent/JPS565502A/en
Publication of JPS633282B2 publication Critical patent/JPS633282B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Optical Elements Other Than Lenses (AREA)
  • Transforming Electric Information Into Light Information (AREA)
  • Overhead Projectors And Projection Screens (AREA)

Abstract

PURPOSE: To prevent the luminance decrease around images by providing a transparent plate which is formed with notches in concentrical circle form at the specified pitch to bend the video light through a projecting lens to the inner side and applying this to a transmission screen.
CONSTITUTION: A transparent plate 5 is formed with notches 6 in concentrical circle form at the specified pitch and these notches 6 are not formed near the center of the transparent plate 5 and are so formed that they become deeper as they to toward the periphery. The transparent plate 5 is provided in proximity to the back of a transmission type screen 3. The peripheral light going from the video light emitting device toward the outer side is entered to the wall surface 6a of the notches 6 of the transparent plate 5 and since the incident angle θ1 thereof is the critical angle or more, total reflection occurs and the light is fetched to the front of the transparent plate 5. On the other hand, the notches 6 are shallower on the central side of the transparent plate 5 and therefore, the reflected light becomes more on the periphery of the transparent plate 5. Since such constitution bends the video light generated by the video light emitting source and passed through the rojecting lens and applies the same to the transmission type screen, the decrease in luminance at the periphery of the images may be prevented.
COPYRIGHT: (C)1981,JPO&Japio
JP8048779A 1979-06-26 1979-06-26 Optical path converting device Granted JPS565502A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8048779A JPS565502A (en) 1979-06-26 1979-06-26 Optical path converting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8048779A JPS565502A (en) 1979-06-26 1979-06-26 Optical path converting device

Publications (2)

Publication Number Publication Date
JPS565502A true JPS565502A (en) 1981-01-21
JPS633282B2 JPS633282B2 (en) 1988-01-22

Family

ID=13719640

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8048779A Granted JPS565502A (en) 1979-06-26 1979-06-26 Optical path converting device

Country Status (1)

Country Link
JP (1) JPS565502A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195237A (en) * 1981-05-27 1982-11-30 Mitsubishi Rayon Co Ltd Fresnel lens for screen
JPS60227240A (en) * 1984-04-26 1985-11-12 Nec Home Electronics Ltd Video projector system
CN1073480C (en) * 1998-05-08 2001-10-24 宁夏有色金属冶炼厂 Method for producing titanium powder aggregates

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49116912A (en) * 1973-03-10 1974-11-08

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49116912A (en) * 1973-03-10 1974-11-08

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195237A (en) * 1981-05-27 1982-11-30 Mitsubishi Rayon Co Ltd Fresnel lens for screen
JPS60227240A (en) * 1984-04-26 1985-11-12 Nec Home Electronics Ltd Video projector system
CN1073480C (en) * 1998-05-08 2001-10-24 宁夏有色金属冶炼厂 Method for producing titanium powder aggregates

Also Published As

Publication number Publication date
JPS633282B2 (en) 1988-01-22

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