Plano lens, rear-projection type projector screen employing the same, and rear-projection type video display apparatus

Claim 2

A rear-projection type projector screen, comprising: a plano lens having a light incident side and a light transmission side; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent to each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said minute transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in a single layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic wherein adjacent sections of the minute transparent balls are non-uniform in a center to periphery direction of the plano lens.

Claim 3

A rear-projection type projector screen as claimed in claim 1 , wherein said plano lens further has a transparent layer disposed between said minute transparent balls and said transparent base member.

Claim 4

A rear-projection type projector screen as claimed in claim 1 wherein said plano lens further has a protective transparent layer formed on said minute transparent balls at a side of said minute transparent balls opposite to said transparent layer.

Claim 5

A rear-projection type projector screen as claimed in claim 1 wherein said plano lens further has a protective transparent base member layer on said transparent base member at a side of said transparent base member opposite said minute transparent balls.

Claim 6

A rear-projection type projector screen as claimed in claim 1 further comprising a Fresnel lens bonded to said light incident side of said plano lens.

Claim 7

A rear-projection type projector screen as claimed in claim 1 further comprising an anti-reflection layer disposed at said light incident side of said plano lens.

Claim 8

A rear-projection type projector screen as claimed in claim 1 further comprising an anti-reflection layer disposed at said light emission side of said plano lens.

Claim 9

A rear-projection type projector screen as claimed in claim 1 further comprising a first anti-reflection layer formed on said light incident side of said plano lens and a second anti-reflection layer formed on said light emission side of said plano lens.

Claim 10

A rear-projection type projector screen as claimed in claim 1 further comprising an protective layer disposed at said light incident side of said plano lens.

Claim 11

A rear-projection type projector screen as claimed in claim 1 further comprising an protective layer disposed at said light emission side of said plano lens.

Claim 12

A rear-projection type projector screen as claimed in claim 1 further comprising a first protective layer formed on said light incident side of said plano lens and a second protective layer formed on said light emission side of said plano lens.

Claim 13

A rear-projection type projector screen as claimed in claim 1 wherein each of said minute transparent balls has a diameter, and wherein each of said minute transparent balls projects from said colored layer by an amount which is 30% or more of said diameter, and wherein said colored layer has a thickness which is less than 70% of said diameter.

Claim 14

A rear-projection type projector screen as claimed in claim 1 wherein said colored layer has an absorbence characteristic selected from the group consisting of absorbence and spectral absorbence and wherein said transparent base member has an absorbence characteristic selected from the group consisting of absorbence and spectral absorbence, and wherein said absorbence characteristic of said colored layer differs in value from said absorbence characteristic of said transparent base member.

Claim 15

A rear-projection type projector screen as claimed in claim 1 wherein each of said minute transparent balls has a diameter which is less than 100 μm.

Claim 16

A rear-projection type projector screen as claimed in claim 1 wherein each of said minute transparent balls has a diameter, and wherein said minute transparent balls collectively exhibit an average diameter, and wherein no one of said minute transparent balls has a diameter which differs from said average diameter by more than 10% of said average diameter.

Claim 17

A rear-projection type projector screen as claimed in claim 1 wherein said transparent base member is disposed at said light incident side and has a refractive index, and wherein each of said minute transparent balls has a refractive index which is larger than said refractive index of said transparent base member.

Claim 18

A rear-projection type projector screen as claimed in claim 16 wherein each of said minute transparent balls has a refractive index which is greater than or equal to 1.4.

Claim 19

A rear-projection type projector screen as claimed in claim 1 wherein said optical characteristic is the refractive index and wherein said plano lens has a peak gain which is greater than or equal to 2.4, and a gain at a bend angle of 30° which is greater than or equal to ⅓ of said peak gain.

Claim 20

A rear-projection type projector screen as claimed in claim 1 wherein said plano lens has a center and a periphery, and wherein said minute transparent balls are distributed in said single ball layer so that said optical characteristic changes gradually from minute transparent balls disposed at said center of said plano lens to minute transparent balls distributed at said periphery of said plano lens.

Claim 21

A rear-projection type projector screen as claimed in claim 1 wherein said plano lens has a center and a periphery, and wherein said minute transparent balls are distributed in said single ball layer so that said optical characteristic changes in steps from minute transparent balls disposed at said center of said plano lens to minute transparent balls distributed at said periphery of said plano lens.

Claim 22

A rear-projection type projector screen as claimed in claim 1 wherein at least some of said minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 23

A rear-projection type projector screen as claimed in claim 1 wherein at least some of said minute transparent balls have a plurality of concave depressions on a surface thereof.

Claim 24

A rear-projection type projector screen as claimed in claim 1 wherein said minute transparent balls have a surface treatment selected from the group of anti-reflection surface treatments and water-repelling surface treatments.

Claim 25

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein adjacent sections of the minute transparent balls are non-uniform in a center to periphery direction of the plano lens.

Claim 26

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein adjacent sections of the minute transparent balls are non-uniform in a center to periphery direction of the plano lens.

Claim 27

A rear-projection type video display apparatus as claimed in claim 24 , wherein said plano lens further has a transparent layer disposed between said minute transparent balls and said transparent base member.

Claim 28

A rear-projection type video display apparatus as claimed in claim 24 wherein said plano lens further has a protective transparent layer formed on said minute transparent balls at a side of said minute transparent balls opposite to said transparent layer.

Claim 29

A rear-projection type video display apparatus as claimed in claim 24 wherein said plano lens further has a protective transparent base member layer on said transparent base member at a side of said transparent base member opposite said minute transparent balls.

Claim 30

A rear-projection type video display apparatus as claimed in claim 24 further comprising a Fresnel lens bonded to said light incident side of said plano lens.

Claim 31

A rear-projection type video display apparatus as claimed in claim 24 further comprising an anti-reflection layer disposed at said light incident side of said plano lens.

Claim 32

A rear-projection type video display apparatus as claimed in claim 24 further comprising an anti-reflection layer disposed at said light emission side of said plano lens.

Claim 33

A rear-projection type video display apparatus as claimed in claim 24 further comprising a first anti-reflection layer formed on said light incident side of said plano lens and a second anti-reflection layer formed on said light emission side of said plano lens.

Claim 34

A rear-projection type video display apparatus as claimed in claim 24 further comprising an protective layer disposed at said light incident side of said plano lens.

Claim 35

A rear-projection type video display apparatus as claimed in claim 24 further comprising a protective layer disposed at said light emission side of said plano lens.

Claim 36

A rear-projection type video display apparatus as claimed in claim 24 further comprising a first protective layer formed on said light incident side of said plano lens and a second protective layer formed on said light emission side of said plano lens.

Claim 37

A rear-projection type video display apparatus as claimed in claim 24 wherein each of said minute transparent balls has a diameter, and wherein each of said minute transparent balls projects from said colored layer by an amount which is 30% or more of said diameter, and wherein said colored layer has a thickness which is less than 70% of said diameter.

Claim 38

A rear-projection type video display apparatus as claimed in claim 24 wherein said colored layer has an absorbence characteristic selected from the group consisting of absorbence and spectral absorbence and wherein said transparent base member has an absorbence characteristic selected from the group consisting of absorbence and spectral absorbence, and wherein said absorbence characteristic of said colored layer differs in value from said absorbence characteristic of said transparent base member.

Claim 39

A rear-projection type video display apparatus as claimed in claim 24 wherein each of said minute transparent balls has a diameter which is less than 100 μm.

Claim 40

A rear-projection type video display apparatus as claimed in claim 24 wherein each of said minute transparent balls has a diameter, and wherein said minute transparent balls collectively exhibit an average diameter, and wherein no one of said minute transparent balls has a diameter which differs from said average diameter by more than 10% of said average diameter.

Claim 41

A rear-projection type video display apparatus as claimed in claim 24 wherein said transparent base member is disposed at said light incident side and has a refractive index, and wherein each of said minute transparent balls has a refractive index which is larger than said refractive index of said transparent base member.

Claim 42

A rear-projection type video display apparatus as claimed in claim 39 wherein each of said minute transparent balls has a refractive index which is greater than or equal to 1.4.

Claim 43

A rear-projection type video display apparatus as claimed in claim 24 wherein said optical characteristic is the refractive index and wherein said plano lens has a peak gain which is greater than or equal to 2.4, and a gain at a bend angle of 30° which is greater than or equal to ⅓ of said peak gain.

Claim 44

A rear-projection type video display apparatus as claimed in claim 24 wherein said plano lens has a center and a periphery, and wherein said minute transparent balls are distributed in said single ball layer so that said optical characteristic changes gradually from minute transparent balls disposed at said center of said plano lens to minute transparent balls distributed at said periphery of said plano lens.

Claim 45

A rear-projection type video display apparatus as claimed in claim 24 wherein said plano lens has a center and a periphery, and wherein said minute transparent balls are distributed in said single ball layer so that said optical characteristic changes in steps from minute transparent balls disposed at said center of said plano lens to minute transparent balls distributed at said periphery of said plano lens.

Claim 46

A rear-projection type video display apparatus as claimed in claim 24 wherein at least some of said minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 47

A rear-projection type video display apparatus as claimed in claim 24 wherein at least some of said minute transparent balls have a plurality of concave depressions on a surface thereof.

Claim 48

A rear-projection type projector screen, comprising: a plano lens having a light incident side and a light transmission side; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent to each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said minute transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in a single layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic wherein at least some of said minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 49

A rear-projection type projector screen, comprising: a plano lens having a light incident side and a light transmission side; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent to each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said minute transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in a single layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic wherein at least some of said minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 50

A rear-projection type projector screen, comprising: a plano lens having a light incident side and a light transmission side; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent to each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said minute transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in a single layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic wherein at least some of said minute transparent balls have a plurality of concave depressions on a surface thereof.

Claim 51

A rear-projection type projector screen, comprising: a plano lens having a light incident side and a light transmission side; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent to each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said minute transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in a single layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic wherein at least some of said minute transparent balls have a plurality of concave depressions on a surface thereof.

Claim 52

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein at least some of the minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 53

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein at least some of the minute transparent balls have a plurality of convex projections on a surface thereof.

Claim 54

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein at least some of the minute transparent balls have a plurality of concave depressions on a surface thereof.

Claim 55

A rear-projection type video display apparatus, comprising: a video projector unit which emits light; a plano lens having a light incident side disposed to receive said light from said video projector unit and a light emission side for emitting said light from said video projector unit after passing through said plano lens; said plano lens having a transparent base member disposed at one of said light incident side and said light emission side; said plano lens also having a plurality of minute transparent balls disposed two-dimensionally in a single ball layer on said transparent layer with said minute transparent balls being substantially adjacent each other; said plano lens also having a colored layer on said transparent layer with said minute transparent balls respectively partially buried in said colored layer so that each of said minute transparent balls has an exposed surface portion projecting from said colored layer toward said light incident side; and each of said transparent balls having an optical characteristic selected from the group consisting of absorbence, spectral absorbence and refractive index, and the optical characteristic of some of said minute transparent balls differing in value from others of said minute transparent balls, and said minute transparent balls being respectively disposed in said single ball layer with a non-uniform two-dimensional distribution of said differing values of said optical characteristic, wherein at least some of the minute transparent balls have a plurality of concave depressions on a surface thereof.