PROJECTION OPTICAL SYSTEM
1 Assignment
0 Petitions
Accused Products
Abstract
A projection optical system receives light from a display device surface and enlarges and projects a display image thereon onto a screen surface. The projection optical system includes one or more reflective surfaces having an optical power between the display device surface and the screen surface, moves at least one optical device having an optical power to adjust focus and satisfies the following conditional formula: −0.02<{(δ1−δ2)β2}/{(δ1+δ2)β1}<0.2 where δ1 and δ2 represent, when the absolute value of a projection magnification is the highest and the lowest, respectively, during focus adjustment, the absolute value of a difference between a distance from the exit pupil of rays incident on the screen upper ends of the screen surface to the screen surface and a distance from the exit pupil of rays incident on the screen lower ends of the screen surface to the screen surface and β1 and β2 represent the maximum value and minimum value, respectively, of the projection magnification when focus is adjusted.
-
Citations
39 Claims
-
1-11. -11. (canceled)
-
12. A projection optical system that receives light from a display device surface and enlarges and projects a display image thereon obliquely onto a screen surface and that varies a projection distance to a screen to display images of different projection magnifications, the projection optical system comprising:
-
one or more reflective surfaces having an optical power between the display device surface and the screen surface, wherein focus is adjusted by moving at least one optical device having an optical power, and conditional formula (1A) below is satisfied;
0.009≦
{(δ
1−
δ
2)δ
2}/{δ
1+δ
2)}<
0.2
(1A)where δ
1 represents, when an absolute value of a projection magnification is highest during focus adjustment, an absolute value of a difference between a distance from an exit pupil of rays incident on screen upper ends of the screen surface to the screen surface and a distance from an exit pupil of rays incident on screen lower ends of the screen surface to the screen surface,δ
2 represents, when the absolute value of the projection magnification is lowest during focus adjustment, the absolute value of the difference between the distance from the exit pupil of rays incident on the screen upper ends of the screen surface to the screen surface and the distance from the exit pupil of rays incident on the screen lower ends of the screen surface to the screen surface,β
1 represents a maximum value of the projection magnification when focus is adjusted (except that β
1 represents, if the projection magnification is negative, a value of the projection magnification when the absolute value thereof is highest) andβ
2 represents a minimum value of the projection magnification when focus is adjusted (except that β
2 represents, if the projection magnification is negative, a value of the projection magnification when the absolute value thereof is lowest). - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A projection optical system that receives light from a display device surface and enlarges and projects a display image thereon obliquely onto a screen surface and that varies a projection distance to a screen to display images of different projection magnifications, the projection optical system comprising:
-
one or more reflective surfaces having an optical power between the display device surface and the screen surface, wherein focus is adjusted by moving at least one optical device having an optical power, and conditional formula (1B) below is satisfied within at least a range specified by a formula “
1.3≦
β
1/β
2≦
1.8”
;
−
0.0028≦
{(δ
1−
δ
2)β
2}/{(δ
1+δ
2)β
1}<
0.2
(1B)where δ
1 represents, when an absolute value of a projection magnification is highest during focus adjustment, an absolute value of a difference between a distance from an exit pupil of rays incident on screen upper ends of the screen surface to the screen surface and a distance from an exit pupil of rays incident on screen lower ends of the screen surface to the screen surface,δ
2 represents, when the absolute value of the projection magnification is lowest during focus adjustment, the absolute value of the difference between the distance from the exit pupil of rays incident on the screen upper ends of the screen surface to the screen surface and the distance from the exit pupil of rays incident on the screen lower ends of the screen surface to the screen surface,β
1 represents a maximum value of the projection magnification when focus is adjusted (except that β
1 represents, if the projection magnification is negative, a value of the projection magnification when the absolute value thereof is highest) andβ
2 represents a minimum value of the projection magnification when focus is adjusted (except that β
2 represents, if the projection magnification is negative, a value of the projection magnification when the absolute value thereof is lowest). - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
-
Specification