IP Library Granted Patent US 8,657,449
Granted Patent B2
US 8,657,449 · App. 13/933,720 · Granted Feb 25, 2014

Projection type display apparatus

Inventors: Nobuyuki Kimura (Yokohama, JP); Koji Hirata (Yokohama, JP)
Assignee: Hitachi Consumer Electronics Co., Ltd.
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Quick Facts
Patent No.
US 8,657,449
App. No.
13/933,720
Granted
Feb 25, 2014
Kind
B2
Abstract

A projection type display apparatus includes: an illumination optical system which has a first array lens and a second array lens each of which has a plurality of lens elements having a plurality of rectangular shape openings and arranged in a matrix form; an illumination light source device which has one or more light sources having a polarization degree not smaller than 50% and one or more polarizers for transmitting one type polarized light and reflecting other type polarized light. At least one set of the light sources are arranged so that the polarization directions of light fluxes having high polarization degrees may be perpendicular to each other, the light fluxes are combined by the polarizer, condensed to a single region by a light-flux condensing element, and then directed toward another illumination optical system located in a subsequent stage.

Claims (13)

1. A projection type display apparatus comprising:

a first and a second illumination light source devices;

an image display element;

an illumination optical system having a plurality of optical elements which illuminates the image display element with light from the first and the second illumination light source devices; and

a projection lens which enlarges an optical image formed by the image display element and projects the enlarged image;

wherein the illumination optical system has first array lens and second array lens each of which has a plurality of lens elements arranged in a matrix form, each lens having a rectangular shape opening and;

wherein the first and the second illumination light source devices each has

a pair of light source units configured by combining a light source of P polarized light having a polarization degree greater than 50% and a light source of S polarized light having a polarization degree greater than 50%,

a polarizing prism which transmits one type polarized light and reflects other type polarized light, and

a polarization conversion element;

wherein the first and a second illumination light source devices are arranged such that the polarization directions of light fluxes having high polarization degrees becomes perpendicular to each other, light fluxes from the first light source unit of the first illumination light source device and from the second light source unit of the second illumination light source device are combined by the polarizing prism, among the combined light fluxes a polarization direction of the light flux from any one of the first light source unit or the second light source unit is changed such that a polarization direction of the light flux becomes perpendicular to a polarization direction of the light flux before changed by the polarization conversion element; and

wherein the light flux from the first illumination light source device is P polarized light, the light flux from the second illumination light source device is S polarized light, the light fluxes are combined by the polarizer which transmits P polarized light and reflects S polarized light and provided in a subsequent stage of the first and second illumination light source devices, the light fluxes are condensed to a single region by a light-flux condensing means, and then directed toward the illumination optical system located in a subsequent stage.

2. A projection type display apparatus according to claim 1 , wherein the light source is a laser.

Assignments (4)
CHANGE OF NAME Recorded Dec 3, 2021
From: MAXELL HOLDINGS, LTD.
To: MAXELL, LTD.
Reel/Frame 058666/0407 →
MERGER Recorded Nov 29, 2021
From: MAXELL, LTD.
To: MAXELL HOLDINGS, LTD.
Reel/Frame 058255/0579 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 25, 2018
From: HITACHI MAXELL, LTD.
To: MAXELL, LTD.
Reel/Frame 045142/0208 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 8, 2014
From: HITACHI CONSUMER ELECTRONICS CO., LTD.; HITACHI CONSUMER ELECTRONICS CO, LTD.
To: HITACHI MAXELL, LTD.
Reel/Frame 033694/0745 →
Priority Claims (1)
JP 2010-017633 · Jan 29, 2010 · national
Continuity (2)
Continuation 12909525 · Oct 21, 2010
Related Publication 20130293848A1 · Nov 7, 2013