US-12619138-B2 - Illuminator and projector

US12619138B2US 12619138 B2US12619138 B2US 12619138B2US-12619138-B2

Abstract

An illuminator includes a light source that emits light; a collimator that parallelizes the light emitted from the light source; a first lens array that receives the light parallelized by the collimator and includes multiple first lenslets; a second lens array that receives light emitted from the first lens array and includes multiple second lenslets; and a light condenser that focuses light emitted from the second lens array at an illuminated region. The light emitted from each of at least two of the first lenslets is incident on one of the second lenslets. A focal plane of the multiple second lenslets is located in an optical path along which the light travels and located upstream from an imaginary plane containing multiple contact points where the first lenslets adjacent to each other in the first lens array are in contact with each other.

Inventors

Shigekazu Aoki
Shoichi Uchiyama

Assignees

SEIKO EPSON CORPORATION

Dates

Publication Date: 20260505
Application Date: 20240726
Priority Date: 20230727

Claims (8)

1 . An illuminator comprising: a light source configured to emit light; a collimator configured to parallelize the light emitted from the light source; a first lens array configured to receive the light parallelized by the collimator and including multiple first lenslets; a second lens array configured to receive light emitted from the first lens array and including multiple second lenslets; and a light condenser configured to focus light emitted from the second lens array at an illuminated region, wherein the light emitted from each of at least two of the first lenslets is incident on one of the second lenslets, a focal plane of the multiple second lenslets is located in an optical path along which the light travels and located upstream from an imaginary plane containing multiple contact points where the first lenslets adjacent to each other in the first lens array are in contact with each other.
2 . The illuminator according to claim 1 , wherein part of first illumination light emitted from one of the multiple second lenslets and part of second illumination light emitted from another of the multiple second lenslets overlap with each other in the illuminated region, and a third optical intensity in a region where the first illumination light and the second illumination light overlap with each other is higher than a first optical intensity in the illuminated region illuminated only with the first illumination light and a second optical intensity in the illuminated region illuminated only with the second illumination light.
3 . The illuminator according to claim 1 , wherein the multiple first lenslets each have a convex first curved surface, the multiple second lenslets each have a convex second curved surface, and a direction in which the first curved surface protrudes is the same as a direction in which the second curved surface protrudes.
4 . The illuminator according to claim 1 , wherein the multiple first lenslets each have a convex first curved surface, the multiple second lenslets each have a convex second curved surface, and a direction in which the first curved surface protrudes is opposite a direction in which the second curved surface protrudes.
5 . A projector comprising: the illuminator according to claim 1 ; a light modulator configured to modulate light emitted from the illuminator; and a projection optical apparatus configured to project the light modulated by the light modulator.
6 . The projector according to claim 5 , wherein the illuminated region is an image formation region of the light modulator.
7 . The projector according to claim 5 , further comprising a controller configured to control the operation of driving the light modulator based on luminance information in image data, wherein the controller is configured to adjust the luminance information in the image data corresponding to an overlapping region where part of first illumination light emitted from one of the multiple second lenslets and part of second illumination light emitted from another of the multiple second lenslets overlap with each other in the illuminated region.
8 . The projector according to claim 7 , further comprising an imager configured to capture a projection image containing the light projected by the projection system, wherein the controller is configured to identify the overlapping region in accordance with an imaging result captured by the imager, and is configured to adjust the luminance information in the image data corresponding to the identified overlapping region.

Description

The present application is based on, and claims priority from JP Application Serial Number 2023-122866, filed Jul. 27, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to an illuminator and a projector. 2. Related Art A display apparatus that projects an image or a video on a projection surface such as a screen, like a projector, performs region segmentation illumination in some cases. In the region segmentation illumination, for example, the light output from a light source is divided into multiple sub-luminous fluxes in a plane that intersects with the optical axis of the light, and the multiple sub-luminous fluxes are radiated onto the illuminated region of a light modulator disposed downstream from the light source. For example, an illuminator of a projector disclosed in JP-A-2022-034731 includes a first lens array that divides light output from an optical apparatus into multiple sub-luminous fluxes, and a second lens array that contributes to radiation of the light output from the first lens array and having a uniform illuminance distribution onto an image formation region of a light modulator. In the illuminator disclosed in JP-A-2022-034731, the focal plane of the second lens array disposed downstream from the first lens array is located at a position shifted from the light incident surface of the first lens array toward the light exiting surface thereof. In the projector disclosed in JP-A-2022-034731, an illuminated region corresponding to a light incident region of a wavelength converter has a lattice-shaped region that includes a central portion and is not irradiated with the light. Heat is therefore readily dissipated in the region that is not irradiated with the light, so that the difference in temperature in the illuminated region is reduced, and a decrease in light use efficiency is suppressed. JP-A-2022-034731 is an example of the related art. In the illuminator disclosed in JP-A-2022-034731, the illuminance in the region of the illuminated region that is not irradiated with the light is lower than the illuminance in the region around the non-illuminated region. When the region segmentation illumination described above is applied to the image formation region of the light modulator of the projector as the illuminated region, a lattice-shaped portion that is not illuminated with the light and therefore has a low optical intensity and illuminance is created between regions illuminated with the multiple sub-luminous fluxes in the image formation region of the light modulator. It is difficult to recover the illuminance having already decreased in the image formation region of the light modulator at a downstream position in the optical path along which the light travels, so that the lattice-shaped dark portion stands out in a projection image and the quality of the projection image therefore decreases in some cases, and improvement in the image quality is therefore desired. SUMMARY An illuminator according to an aspect of the present disclosure includes: a light source configured to emit light; a collimator configured to parallelize the light emitted from the light source; a first lens array configured to receive the light parallelized by the collimator and including multiple first lenslets; a second lens array configured to receive light output from the first lens array and including multiple second lenslets; and a light condenser configured to focus light emitted from the second lens array at an illuminated region. The light emitted from each of at least two of the first lenslets is incident on one of the second lenslets, and a focal plane of the multiple second lenslets is located in an optical path along which the light travels and located upstream from an imaginary plane containing multiple contact points where the first lenslets adjacent to each other in the first lens array are in contact with each other. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the configuration of a projector according to an embodiment. FIG. 2 is a schematic view of an illuminator of the projector shown in FIG. 1. FIG. 3 is a schematic view of key parts of the projector shown in FIG. 1. FIG. 4 is a schematic view of a part of a light incident surface of a light modulator of the projector shown in FIG. 1. FIG. 5 is another schematic view of the part of the light incident surface of the light modulator of the projector shown in FIG. 1. FIG. 6 is a diagrammatic view showing a principle of correcting the optical intensity in an illuminated region in the projector shown in FIG. 1. FIG. 7 is a diagrammatic view showing a principle of correcting the optical intensity in the illuminated region in a projector according to Comparative Example. DESCRIPTION OF EMBODIMENTS An embodiment of the present disclosure will be described below with reference to the drawings. In the drawings, components are drawn at