JP2001174814A - Integrator illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vignetting in the image of arc of a light source lamp formed on a polarization converting device and to improve the conversion efficiency of polarization. SOLUTION: Rays from the lamp 2 of a light source 1 are condensed by integrator lenses 3, 4 and the polarizing plane of the rays is aligned by a polarization converting device 5. The rays pass a condenser lens 6 to illuminate a liquid crystal display plate 7 and the modulated image rays are projected by a projector lens 8 onto a screen. Each lens cell of the integrator lens 3 is formed corresponding to the liquid crystal display plate, and the optical axes of specified lens cells are deviated. Specified lens cell of the integrator lens 4 are formed into a proper size in such a manner that rays from the lens cells of the integrator lens 3 are condensed on the polarization converting device. The polarization converting device is formed corresponding to the size of the lens cells of the integrator lens 4 by varying thickness of specified elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrator illuminating device used for a projection type image display device such as a liquid crystal projector, which optimizes the shapes of an integrator lens and a polarization conversion element to improve polarization conversion efficiency.

[0002]

2. Description of the Related Art In an integrator illuminating device such as a liquid crystal projector, as shown in FIG. 6, light beams from a light source lamp are condensed by integrator lenses 21 and 22, and a polarization plane is aligned by a polarization conversion element 23. Irradiate the liquid crystal display panel through the. Light rays (image light rays) modulated by the liquid crystal display panel are projected on a screen by a projection lens. In the integrator illumination system, since the image of the lens cell of the integrator lens 21 forms an image on the liquid crystal display panel, the shape of each lens cell is similar to that of the liquid crystal display panel as shown in FIG. The cell has a shape corresponding to this, and the lenses have different radii of curvature. And
An arc image of a lamp is formed on the polarization conversion element 23 in order to increase the light collection efficiency of the light beam passing through the polarization conversion element 23. FIG. 8 shows an arc image formed on the polarization conversion element 23. The shaded portion 31 shown in the enlarged view A is not a ray in the polarization direction to be used, but a wasteful portion which is absorbed by the polarizing plate and becomes heat. is there.

[0003]

As described above, the portion of the arc image of the lamp that cannot be accommodated in each cell of the polarization conversion element is "blown", and does not become an effective polarized light beam but is absorbed by the polarizing plate. Temperature rises. It is an object of the present invention to improve the polarization conversion efficiency by adjusting the cell size and shape of the integrator lens to a shape that does not cause "sharpness" of the arc image, and simultaneously adjusting the shape of the polarization conversion element.

[0004]

In order to achieve the above object, in the integrator illuminating device according to the present invention, a light beam of a light source lamp is condensed by a first integrator lens and a second integrator lens, and a polarization plane is polarized by a polarization conversion element. Align,
In the case of irradiating a liquid crystal display panel through a condensing lens, the first integrator lens forms each lens cell in a shape corresponding to the shape of the liquid crystal display panel and decenters the optical axis of a predetermined lens cell. The second integrator lens is formed such that light rays from each lens cell of the first integrator lens are focused on the polarization conversion element.
A predetermined lens cell is formed with an appropriate cell size, and the polarization conversion element is formed by changing the thickness of the predetermined element corresponding to the cell size of the lens cell of the second integrator lens, and formed on the polarization conversion element. Avoid "shaking" of the arc image of the light source lamp being imaged.

In this case, the polarization conversion element may be attached to the second integrator lens to be integrated.

[0006] The polarization conversion element may be divided into three blocks, and each polarization conversion element may be attached to the second integrator lens and integrated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a main part configuration diagram of an embodiment of an integrator lighting device according to the present invention. 1 is a light source, 2 is a light source lamp (such as a metal halide lamp or a high-pressure mercury lamp), 3 is a first integrator lens, 4 is a second integrator lens, 5 is a polarization conversion element, 6 is a condenser lens, and 7 is a liquid crystal display. A plate 8 is a projection lens. Light from the lamp 2 of the light source 1 is condensed by the integrator lenses 3 and 4, the polarization planes are aligned by the polarization conversion element 5, and the liquid crystal display panel 7 is irradiated via the condensing lens 6. The light beam (image light beam) modulated by the liquid crystal display panel 7 is projected on a screen by a projection lens 8. Actually, the liquid crystal display panel 7 has three plates for red, green and blue, and a color separation system for separating the light from the lamp 2 into three colors of red, green and blue is provided between the liquid crystal display plate 7 and the condenser lens 6. A color synthesizing system for synthesizing light beams of three colors is provided between the three liquid crystal display panels 7 and the projection lens 8.

In the integrator illuminating device, since the image of the lens cell of the first integrator lens 3 forms an image on the liquid crystal display panel 7, as shown in the front view of FIG. The shape of the lens cells is similar to that of the liquid crystal display panel 7, and each lens cell has a top view and a side view (a to h,
(A to H correspond to the same reference numerals in the front view)), the optical axis is decentered, and the focal length is set including the integrator lens 4 described later so that the light beam is focused on the polarization conversion element 5. That is, four stages a to d in row a and E to E in row A
The lens cells of the four stages of H and the columns of the rows are decentered with respect to the optical axis above the center, and the four stages of the columns e to h and the columns A to D
And the optical axes of the lens cells of the four stages and the rows of the columns are decentered below the center, and at the same time, the optical axes of the lens cells of the left column a, the right column A, and the left column are decentered right from the center. Then, the optical axes of the lens cells in the right column a, the left column A, and the right column are decentered to the left from the center.

Then, the second integrator lens 4
Corresponding to the first integrator lens 3 (6 rows vertically × 8 rows horizontally), as shown in FIG. 3, there are 4 rows vertically, and the center two rows (′) are eight rows of lens cell groups, Two rows are horizontal
A lens cell group consisting of 16 stages, the width of each lens cell in the center two rows is set to の of the width of the lens cells in both the left and right rows, and each of the center two rows of 'stage' and 'stage' lens cells Is twice as long as the lens cells in the left and right rows, and the vertical width of each of the 'cells' and 'rows' is about 2.5 times that of the lens cells in both the right and left rows. The vertical width of the cell is about 2.3 times that of the lens cells in the left and right rows, and the vertical width of each of the 'stage' and 'stage' lens cells is about 1.2 times the lens cells in the left and right rows. Then, the optical axes of the lens cells in the two rows of the 'and' stages are decentered below the center, and the optical axes of the lens cells in the 'and' stages are decentered above the center. Each lens cell has a shape in which the upper half is cut off from the optical axis, and each lens cell in the step 'has a shape in which the lower half is cut off from the optical axis. The odd-numbered steps (a', b) ) Is a shape obtained by cutting the lower half from the optical axis, and the lens cells of the even-numbered stages (A ′, B ′,. Into a cut shape, and at the same time,
The optical axis of each lens cell of the odd-numbered stage from the top of the leftmost column and the even-numbered stage of the rightmost column is decentered to the left from the center, and from the top of the leftmost column and from the top of the even-numbered stage and the rightmost column. The optical axis of each odd-numbered lens cell is decentered to the right from the center.

Thus, the first integrator lens 3
Of the second integrator lens 4 are located at the center left column of the second integrator lens 4.
, The light beam passing through the lens cells in the rightmost column of the first integrator lens 3 passes through the lens cells in the rightmost column of the second integrator lens 4, and
Each of the light beams condensed on the polarization conversion element and passed through the lens cells A to H in the second column from the left of the first integrator lens 3 are even-numbered lens cells from the leftmost column of the second integrator lens 4 H ', the second row of lens cells A to
The light beams passing through H pass through even-numbered lens cells A ′, B ′,... H ′ from the rightmost row of the second integrator lens 4 and are condensed on the polarization conversion elements, respectively. 3 pass through the odd-numbered lens cells a ', b',... H 'from the leftmost column of the second integrator lens 4, and pass through the first integrator lens. 3 pass through the odd-numbered lens cells a ′, b ′,... H ′ from the rightmost column of the second integrator lens 4.
Each is focused on a polarization conversion element.

As shown in FIG. 4A, the light beam passing through the first integrator lens 3 and the second integrator lens 4 enters the polarization conversion element 5, and the s-polarized light beam is reflected and emitted by the polarization splitting surface, and is polarized. The p-polarized light transmitted through the separation surface is converted into an s-polarized light by the retardation film 11 or 12,
The liquid crystal display panel is irradiated with these s-polarized light beams. In the polarization conversion element 5, portions corresponding to the two small central rows of the lens cells of the second integrator lens 4 are thin, and portions on both sides are thick corresponding to the lens cells. By sticking the polarization conversion element 5 to the second integrator lens 4 and integrating the same, the trouble of adjusting the alignment can be omitted, and as shown in (b), the thickness of the polarization conversion element 5 can be reduced. Separation into three different elements simplifies manufacturing. Also in this case, sticking and integrating with the second integrator lens 4 is an effective means for saving the trouble of adjusting the alignment as described above.

As described above, as shown in FIG. 5, the arc image of the lamp 2 is formed on the polarization conversion element 5 without causing "shaking", and the light collection efficiency of the light beam passing through the polarization conversion element 5 is improved. be able to.

[0013]

As described above, according to the integrator illuminating device of the present invention, the cell size and the shape (eccentricity of the optical axis) of the integrator lens are optimized, and at the same time, the shape of the polarization conversion element is adjusted to this. This eliminates the "blurring" of the arc image of the lamp formed on the polarization conversion element, eliminates the factor that is absorbed by the polarizing plate and raises the temperature, and improves the polarization conversion efficiency.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram of an embodiment of an integrator lighting device according to the present invention.

FIG. 2 is a main part configuration diagram of an example of an integrator lens 3 of the present invention.

FIG. 3 is a main part configuration diagram of an example of an integrator lens 4 of the present invention.

FIG. 4 is an example of a combination of an integrator lens and a polarization conversion element according to the present invention.

FIG. 5 is an example of an arc image formed on the polarization conversion element of the present invention.

FIG. 6 is a main part configuration diagram of an example of a conventional integrator lens.

FIG. 7 is an example of a combination of a conventional integrator lens and a polarization conversion element.

FIG. 8 is an example of an arc image formed on a conventional polarization conversion element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Lamp 3, 21 1st integrator lens 4, 22 2nd integrator lens 5, 13, 14, 15, 23 Polarization conversion element 6 Condensing lens 7 Liquid crystal display panel 8 Projection lens 11, 12 Phase difference film 31 Arc image "Kere"

Claims (4)

[Claims] 1. A method of irradiating a liquid crystal display panel via a condenser lens, wherein a light beam from a light source lamp is condensed by a first integrator lens and a second integrator lens, a polarization plane is aligned by a polarization conversion element, and the condensing lens is illuminated. The first integrator lens is formed such that each lens cell has a shape corresponding to the shape of the liquid crystal display panel and the optical axis of a predetermined lens cell is decentered, and the second integrator lens is formed of the first integrator lens. A predetermined lens cell is formed to have an appropriate cell size so that light rays from each lens cell are converged on the polarization conversion element, and the polarization conversion element has a cell size of the lens cell of the second integrator lens. An integrator lighting device formed by changing the thickness of a predetermined element in accordance with the requirements. 2. The integrator lighting device according to claim 1, wherein the polarization conversion element is attached to and integrated with a second integrator lens. 3. The integrator illumination device according to claim 1, wherein said polarization conversion element is formed by dividing into three blocks. 4. The integrator lighting device according to claim 3, wherein the polarization conversion elements divided into three blocks are respectively attached to a second integrator lens and integrated.