JP2019211562A - Lighting unit and projector - Google Patents

Abstract

To provide a lighting unit that increases the degree of freedom of the size of a light source and a radiation area of light emitted from the light source, and can be reduced in size.SOLUTION: A lighting unit according to the present invention comprises: a light emitting device that includes a light emitting surface having a longitudinal direction; a polarization conversion device 33A that includes a plurality of polarization prisms PP having a longitudinal direction; a lens array that is provided between the light emitting device and polarization conversion device 33A and has a plurality of rectangular lenses; and a light modulation device that modulates light emitted from the light emitting device and passing through the polarization conversion device 33A. In the lighting unit according to the present invention, a direction along the contour of the lenses and the longitudinal direction of the light emitting surface of the light emitting device intersect each other, and a direction along the contour of the lenses and the longitudinal direction DP of the polarization prisms PP intersect each other.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a lighting device and a projector.

  In general, a projector that divides light emitted from a high-brightness light source into light of a plurality of colors (wavelengths) and predetermined polarization directions by a polarization separation film or a reflection film, and irradiates each light to a transmissive liquid crystal panel Are known. As a light source used in such a projector, a discharge type light source has been conventionally used, but in recent years, a solid light source such as an LED or a semiconductor laser is often used.

  In LEDs and semiconductor lasers, the irradiation area in the plane perpendicular to the optical axis often becomes an elliptical shape or a rectangular shape with different aspect ratios due to the downsizing of the light source, the shape of the light emitting surface, and manufacturing problems. For example, Patent Document 1 describes that the major axis direction of glass used in a polarization conversion element is aligned with the longitudinal direction of light having an elliptical shape or a rectangular shape emitted from a light source. Yes.

JP 2006-071128 A

  As described above, when a light source that emits light in an elliptical or rectangular irradiation area is used in a liquid crystal projector that requires polarization conversion, the size of the light source is limited by the polarization conversion element in the liquid crystal projector, and the light output is reduced. There was a problem of lowering. In the light source device described in Patent Document 1, although the degree of freedom of the size of the light source and the irradiation area of the light emitted from the light source is expanded, improvement in the utilization efficiency of the light emitted from the light source and the miniaturization of the lighting device have been desired. .

  The present invention has been made in consideration of the above-described circumstances, and provides an illumination device and a projector that improve the utilization efficiency of light emitted from a light source and can realize downsizing.

  According to the first aspect of the present invention, the light emitting surface is provided between the light emitting element having a longitudinal direction, the polarization converting element having a plurality of polarizing prisms having the longitudinal direction, and the light emitting element and the polarization converting element. And a lens array having a plurality of rectangular lenses, and a light modulation element that modulates light emitted from the light emitting element and passed through the polarization conversion element, the direction along the outer shape of the lens and the light emission There is provided an illuminating device characterized in that the longitudinal direction of the light emitting surface of the element intersects with each other, and the direction along the outer shape of the lens intersects with the longitudinal direction of the polarizing prism of the polarization conversion element. The

  According to the illumination device according to the first aspect described above, by aligning the longitudinal direction of the light emitting surface and the longitudinal direction of the polarizing prism with respect to the solid-state light source having the light emitting surface having the longitudinal direction, light loss in the polarization conversion element is reduced. Decrease. Further, since the irradiation areas (that is, light source images) formed on the polarization conversion element are arranged in a straight line, the light transmittance in the polarization conversion element is improved. As a result, the utilization efficiency of the light emitted from the light source is improved and the size can be reduced.

  In the illumination device according to the first aspect, the plurality of lenses have longitudinal directions in the same direction, and the longitudinal direction of the light emitting surface is in the direction perpendicular to the longitudinal direction of the lenses with respect to the longitudinal direction of the lenses. You may have the inclination equivalent to the ratio of the width of the said lens of the direction parallel to the longitudinal direction of the said lens with respect to the width of a lens.

  Further, in the illumination device according to the first aspect, the plurality of lenses have longitudinal directions in the same direction, and are arranged in the longitudinal direction of the lenses in a plane orthogonal to the traveling direction of the light emitted from the light emitting element. A row in which the plurality of lenses are arranged along a direction orthogonal to each other is provided with a predetermined step with respect to a row adjacent in parallel to the longitudinal direction of the lens, and the longitudinal direction of the light emitting surface is in the longitudinal direction of the lens. The predetermined step may be represented by a product of the predetermined angle and a longitudinal width of the lens.

  In the illumination device according to the first aspect, the plurality of lenses have longitudinal directions in the same direction, and the longitudinal direction of the light emitting surface is within a plane orthogonal to the traveling direction of the light emitted from the light emitting element. Is inclined at a predetermined angle with respect to the longitudinal direction of the lens in a direction orthogonal to the longitudinal direction of the lens, and is deviated with a predetermined amount of eccentricity, and the predetermined amount of eccentricity is equal to the predetermined angle. It may be represented by the product of the width in the longitudinal direction of the lens.

  According to the optical element according to the first aspect described above, the optical loss in the polarization conversion element is reduced as described above. In addition, since the irradiation area and the light source image formed on the polarization conversion element are arranged in a straight line, the light transmittance in the polarization conversion element is improved. Accordingly, the utilization efficiency of light emitted from the light emitting element is improved, and the lighting device can be downsized.

  According to the first aspect of the present invention, the illumination device includes the above-described illumination device, and the light modulation element forms image light by modulating light emitted from the light emitting element according to image information, A projector further provided with a projection optical system for projecting image light is provided.

  According to the projector according to the first aspect described above, it is possible to increase the brightness and reduce the size by providing the illumination device that suppresses the light loss in the polarization conversion element.

It is the schematic which shows the structure of the projector which concerns on 1st Embodiment. It is the schematic of the illumination light production | generation optical system of the projector shown in FIG. It is a perspective view of the light emitting element of the illumination light generation optical system shown in FIG. It is a perspective view of the lens array of the integrator optical system of the illumination light generation optical system shown in FIG. It is a schematic diagram which shows the irradiation area | region of the light irradiated to the 2nd lens array in the illumination light production | generation optical system shown in FIG. FIG. 2 is a perspective view of a polarization conversion element of the illumination light generation optical system shown in FIG. 1 and a diagram showing an irradiation region of spot-like white light LW irradiated on the polarization conversion element. It is the schematic showing the modification of the light source optical system of the illumination light production | generation optical system shown in FIG. It is the schematic which shows a mode that the blue light of S polarization is irradiated to the light emitting element of the light source optical system shown in FIG. 7, and fluorescence as yellow light is produced | generated. In 2nd Embodiment, it is a schematic diagram which shows the irradiation area | region of the light irradiated to the 2nd lens array in an illumination light production | generation optical system. It is a perspective view of the polarization conversion element in 2nd Embodiment, and the figure which shows the irradiation area | region of the spot-like white light irradiated to a polarization conversion element. In 3rd Embodiment, it is a schematic diagram which shows the irradiation area | region of the light irradiated to the 2nd lens array in an illumination light production | generation optical system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

(First embodiment)
First, an example of an optical element and a projector according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram illustrating a configuration of a projector 1 according to the first embodiment.

  As shown in FIG. 1, the projector 1 according to the first embodiment is a projection-type image display device that displays a color image on a screen (not shown). The projector 1 includes the illumination device 14 </ b> A according to the first embodiment, the combining optical device 5, and the projection optical system 6. The illumination device 14A includes c11A, a color separation optical system 3, and light modulation devices (light modulation elements) 4R, 4G, and 4B.

  The illumination light WL including at least the three primary colors of red light LR, green light LG, and blue light LB is emitted from the illumination light generation optical system 11A. In the present embodiment, the illumination light WL is white light. In this specification, red light LR indicates visible blue light having a peak wavelength of 590 nm to 700 nm, green light LG indicates visible green light having a peak wavelength of 500 nm to 590 nm, and blue light LB. Means visible blue light having a peak wavelength of 400 nm to 500 nm.

  FIG. 2 is a schematic diagram showing a configuration of the illumination light generation optical system 11A. As shown in FIG. 2, the illumination light generation optical system 11 </ b> A includes a light emitting element 20, a pickup lens 21, an integrator optical system 31, a polarization conversion element 33, a phase difference plate 35, and a superimposing lens 43. The light emitting element 20 and the pickup lens 21 constitute a light source optical system 41A. The integrator optical system 31, the polarization conversion element 33, and the phase difference plate 35 divide the light emitted from the light source optical system 41A to convert each polarization direction into a desired direction, and convert the plurality of lights after polarization conversion. A superimposing optical system 42 for superimposing is configured.

  The light emitting element 20 of the present embodiment is configured by one light emitting element 20A, and the light emitting element 20A emits white light LW including light of three primary colors of red light LR, green light LG, and blue light LB. The light emitting element 20A is, for example, a white LED. FIG. 3 is a schematic diagram of the light emitting element 20A. As shown in FIG. 3, the light emitting element 20A includes a light emitting surface 20e having a longitudinal direction D1. White light (light emitted from the light emitting element) LW emitted from the light emitting element 20A having the light emitting surface 20e described above is a surface orthogonal to the optical axis X (surface orthogonal to the traveling direction of the light emitted from the light emitting element). ), An irradiation region having a longitudinal direction D1 is formed. The white light LW is collimated by the biconvex lenses 21a and 21b of the pickup lens 21 to become parallel rays. The light that has become parallel rays enters the integrator optical system 31.

  The integrator optical system 31 includes a first lens array 31a and a second lens array (lens array) 31b. FIG. 4 is a perspective view of the first lens array 31a and the second lens array 31b. As shown in FIG. 4, in each of the first lens array 31a and the second lens array 31b, a plurality of microlenses (lenses) M are arranged in an array within a plane orthogonal to the optical axis X of parallel rays. Consists of things. The plurality of microlenses M have a longitudinal direction DM in the same direction.

  As shown in FIG. 5, the microlens M is formed in a rectangular shape, and has a vertical width (a lens width in a direction perpendicular to the longitudinal direction of the lens) A and a lateral width (a lens width in a direction parallel to the longitudinal direction of the lens). B. In the present embodiment, the light emitting element 20 is arranged so that the longitudinal direction D1 of the light emitting surface 20e of the light emitting element 20A has an inclination of (−A / B) with respect to the longitudinal direction DM of the microlens M. That is, the direction DA along the short side of the microlens M (direction along the outer shape of the lens) DA and the direction along the long side (direction along the outer shape of the lens) DB and the longitudinal direction D1 of the light emitting surface 20e are orthogonal to each other. Yes.

  The white light LW incident on the integrator optical system 31 is divided into a plurality of spot arrays by the first lens array 31a in accordance with the arrangement and the number of microlenses M. The plurality of spot array-shaped white lights LW emitted from the first lens array 31a are applied to the second lens array 31b. FIG. 5 is a schematic diagram illustrating an irradiation area of the white light WL irradiated to the second lens array 31b. As described above, since the light emitting element 20A is arranged so that the longitudinal direction D1 of the light emitting surface 20e has an inclination of (−A / B) with respect to the longitudinal direction DM of the microlens M, as shown in FIG. In addition, a plurality of spot array-shaped white light LW irradiation regions (that is, light source images of the light emitting elements 20A) are formed to have an inclination of (−A / B) with respect to the longitudinal direction DM of the microlens M. . That is, the irradiation area of the spot-array-shaped white light LW is formed so that the longitudinal direction overlaps the diagonal line of the microlens M. In such a configuration, the spot array-shaped white light LW having the longitudinal direction is incident on the second lens array 31b without being lost by the microlens M and making the most of the area of the microlens M. The spot array-shaped white light LW incident on the second lens array 31 b is collimated by the second lens array 31 b and is irradiated to the polarization conversion element 32.

  FIG. 6 is a perspective view of the polarization conversion element 33A of the present embodiment and a diagram showing an irradiation area of the spot-like white light LW irradiated to the polarization conversion element 33A. As shown in FIG. 6, the polarization conversion element 32 includes a plurality of polarizing prisms PP having a longitudinal direction DP and a plurality of light shielding portions N. The polarizing prism PP and the light shielding part N are parallel to each other and are alternately arranged in the vertical direction. In the polarization conversion element 33A, the longitudinal direction DP of the polarizing prism PP has an inclination (−A / B) with respect to the longitudinal direction DM of the microlenses M of the first lens array 31a and the second lens array 31b. Have been placed. That is, at least two light source images among the plurality of light source images formed by the white light LW emitted from the light emitting element 20A passing through the second lens array 31b are on a virtual line and a straight line along the longitudinal direction DP. It is preferable that all light source images are arranged in a straight line on the virtual line. Further, the direction DA along the short side of the microlens M, the direction DB along the long side, and the longitudinal direction DP of the polarizing prism PP intersect each other. The spot array-shaped white light LW emitted from the polarization conversion element 33A is aligned with P-polarized light or S-polarized light.

  The phase difference plate 35 gives a predetermined phase difference to the white light LW emitted from the polarization conversion element 33A. In the first embodiment, the predetermined phase difference is a half wavelength corresponding to each color included in the white light LW, that is, π. The fast axis of the retardation plate 35 is (π / 4) + arcos (A / 2B) [rad. ] Are arranged at an angle. The spot-like white light LW that has passed through the phase difference plate 35 is aligned with polarized light different from that immediately after being emitted from the polarization conversion element 33A among P-polarized light and S-polarized light.

  White light LW emitted from the phase difference plate 35 enters the superimposing lens 43. The superimposing lens 43 cooperates with the integrator optical system 31 to uniformize the illuminance distribution of the white light LW in the illuminated area. The white light LW emitted from the superimposing lens 43 enters the color separation optical system 3 shown in FIG. 1 as illumination light WL including light of the three primary colors of red light LR, green light LG, and blue light LB. In this way, the illumination light generation optical system 11A emits the illumination light WL.

  As shown in FIG. 1, the color separation optical system 3 separates the illumination light WL into a red light LR, a green light LG, and a blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, a field lens 9 and a third total reflection mirror 8c. Is provided. The first dichroic mirror 7a separates the illumination light WL from the illumination device 14A into blue light LB and light of a color other than blue (that is, green light LG and red light LR). The first dichroic mirror 7a transmits the blue light LB and reflects the separated green light LG and red light LR. The second dichroic mirror 7b reflects the green light LG and transmits the red light LR.

  The first total reflection mirror 8a reflects the blue light LB toward the light modulation device 4B. The second total reflection mirror 8b and the third total reflection mirror 8c guide the red light LR to the light modulation device 4R. The green light LG is reflected from the second dichroic mirror 7b toward the light modulation device 4G.

  The light modulation device 4B modulates the blue light LB according to the image information to form blue image light. The light modulation device 4G modulates the green light LG according to image information to form green image light. The light modulation device 4R modulates the red light LR in accordance with the image information to form red image light. That is, the light modulation devices 4B, 4G, and 4R modulate light emitted from the light emitting element 20A of the illumination light generating optical system 11A and passing through the polarization conversion element 33A. For the light modulation devices 4B, 4G, and 4R, for example, transmissive liquid crystal panels are used.

  Field lenses 10B, 10G, and 10R and polarizing plates 12B, 12G, and 12R are disposed on the incident side of the light modulation devices 4B, 4G, and 4R. Polarizers 16B, 16G, and 16R are disposed on the exit side of the polarizers 12B, 12G, and 12R, that is, between the polarizers 12B, 12G, and 12R and the combining optical device 5, respectively. The polarizing plates 12B, 12G, and 12R and the polarizing plates 16B, 16G, and 16R are for appropriately changing and adjusting the polarizations of the light beams LB, LG, and LR of each color, and each of them is composed of two or more polarizing plates. It may be configured and may further include a half-wave plate.

  Blue, green, and red image lights formed by the light modulation devices 4B, 4G, and 4R are incident on the combining optical device 5. The combining optical device 5 combines the blue, green, and red image lights and emits the combined image light toward the projection optical system 6. For example, a cross dichroic prism is used for the combining optical device 5.

  The projection optical system 6 projects the image light combined by the combining optical device 5 while enlarging it toward the screen. An enlarged color image is displayed on the screen. For the projection optical system 6, for example, a combined lens including a lens barrel and a plurality of lenses disposed in the lens barrel is used.

According to 14 A of illuminating devices which concern on 1st Embodiment demonstrated above, there exist the following effects.
The illumination device 14A of the first embodiment includes a light emitting element 20A having a light emitting surface 20e having a longitudinal direction D1, a polarization conversion element 33A having a plurality of polarizing prisms PP having a longitudinal direction DP, and the light emitting element 20A on the optical axis X. A lens array 31b provided between the polarization conversion element 33A and having a plurality of rectangular microlenses M; and a light modulation device 4B that modulates light emitted from the light emitting element 20A and passed through the polarization conversion element 33; 4G, 4R. In the illuminating device 14A of the first embodiment, the directions DA and DB along the outer shape of the microlens M and the longitudinal direction D1 of the light emitting surface 20e intersect each other, and the directions DA and DB and the longitudinal direction DP of the polarizing prism PP Cross each other. Specifically, in the illumination device 14A of the first embodiment, the plurality of microlenses M have the same longitudinal direction DM, and the light emitting surface 20e has a longitudinal direction D1 with respect to the longitudinal direction DM of the microlens M. -It has an inclination of (vertical width A of microlens M / horizontal width B of microlens M).

  According to the illuminating device 14A of the first embodiment, white light from the light emitting element 20A is obtained by aligning the longitudinal direction M1 and the longitudinal direction DP with respect to a solid light source such as a white LED having a light emitting surface 20e having the longitudinal direction M1. The light loss at the polarization conversion element 33A can be reduced by allowing the LW spot to pass through the polarizing prism PP without being lost at the light shielding portion N. In addition, since the irradiation regions (that is, light source images) formed on the polarization conversion element 33A are arranged in a straight line, the light transmittance in the polarization conversion element 33A can be improved. As a result, the utilization efficiency of the white light LW emitted from the light emitting element 20A in the illumination device 14A can be improved, and the illumination device 14A can be downsized.

  The projector 1 according to the first embodiment includes the above-described illumination device 14A according to the first embodiment, the combining optical device 5, and the projection optical system 6. By providing the illuminating device 14A, also in the projector 1 of the first embodiment, the utilization efficiency of the white light LW emitted from the light emitting element 20 can be improved and the size can be reduced. In particular, a projector with high brightness can be obtained by using an illumination device that suppresses light loss in the polarization conversion element 33A.

  Note that the longitudinal direction D1 of the light emitting surface 20e may have an inclination of + (A / B) with respect to the longitudinal direction DM of the microlens M because of symmetry in a plane orthogonal to the optical axis X. In that case, in the polarization conversion element 33A, the longitudinal direction DP of the polarizing prism PP has an inclination of + (A / B) with respect to the longitudinal direction DM of the microlenses M of the first lens array 31a and the second lens array 31b. Arranged to have.

(Modification of the first embodiment)
Next, modified examples of the illumination device 14A and the projector 1 according to the first embodiment will be described. Note that, in the drawings used in the following embodiments and the description of the modifications, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.

  FIG. 7 is a schematic diagram illustrating a configuration of a light source optical system 41B that is a modification of the light source optical system 41A of the illumination light generation optical system 11A described in the first embodiment. In the modification of the illumination device 14A and the projector 1 according to the first embodiment, the light source optical system 41A of the illumination light generation optical system 11A is replaced with a light source optical system 41B.

  As shown in FIG. 7, the light source optical system 41 </ b> B includes a light emitting element 20, a polarization separation mirror 24, pickup lenses 21 and 22, a reflection diffusion plate 25, and a phase difference plate 26.

  The light emitting element 20 of the present modification is composed of two light emitting elements 20B and 20C and a beam shaping element 23. The light emitting element 20B is a blue laser light source that emits blue light LB. The blue light LB emitted from the light emitting element 20B and before entering the beam shaping element 23 has substantially no longitudinal direction, and the irradiation area of the blue light LB on the plane orthogonal to the optical axis X is substantially a perfect circle. is there. The light emitting element 20C is a yellow phosphor that is excited by the blue light LB and emits fluorescence of the yellow light LY including the green light LG and the red light LR. The beam shaping element 23 shapes the substantially circular blue light LB emitted from the light emitting element 20 </ b> B into an elliptical or rectangular blue light LB having the longitudinal direction D <b> 1 and emits it toward the polarization separation mirror 24. . The exit surface that contributes to the shaping of the blue light LB in the beam shaping element 23 functions as the light emitting surface 20e described in the first embodiment.

  The polarization separation mirror 24 reflects only the S-polarized blue light LB (S) and transmits the P-polarized blue light LB, the S-polarized light, and the P-polarized yellow light LY. For the polarization separation mirror 24, for example, a polarization dichroic mirror is used. The blue light LB (S) reflected by the polarization separation mirror 24 passes through the pickup lens 21 and enters the light emitting element 20C.

  FIG. 8 is a schematic diagram illustrating a state in which S-polarized blue light LB (S) is irradiated on the light-emitting element 20C that is a yellow phosphor, and fluorescence as yellow light LY is generated. As shown in FIG. 8, the blue light LB (S) incident on the light emitting element 20C excites the yellow phosphor, and the yellow light LY is emitted from the yellow phosphor. At this time, the blue light LB (S) incident on the yellow phosphor has a longitudinal direction D1. Therefore, the yellow light LY emitted from the light emitting element 20C which is a yellow phosphor also has the longitudinal direction D1. As shown in FIG. 7, the yellow light LY emitted from the light emitting element 20 </ b> C passes through the pickup lens 21 and passes through the polarization separation mirror 24.

  On the other hand, among the blue light LB emitted from the beam shaping element 23, the P-polarized blue light LB (P) also has the longitudinal direction D1 like the blue light LB (S). To Penetrate. The phase difference plate 26 gives a predetermined phase difference to the blue light LB. In this modification, the predetermined phase difference is a quarter wavelength of the blue light LB, that is, (π / 2). The reflection diffusion plate 25 reflects the incident blue light LB while diffusing it. The blue light LB (P) transmitted through the polarization separation mirror 24 passes through the phase difference plate 26 and the pickup lens 22 composed of the biconvex lenses 22a and 22b, and enters the reflection diffusion plate 25. The blue light LB reflected by the reflection diffusion plate 25 passes through the pickup lens 22 and the phase difference plate 26 again, is converted into blue light LB (S), and enters the polarization separation mirror 24. The blue light LB (S) converted into S-polarized light by the phase difference plate 26 is reflected by the polarization separation mirror 24 and together with the yellow light Y transmitted through the polarization separation mirror 24 as described above, the first embodiment shown in FIG. It enters the superimposing optical system 42 of the form.

  The behavior and operation of the blue light LB (S) and the yellow light LY in the superimposing optical system 42, the color separation optical system 3, the light modulation devices 4B, 4G, and 4R, the combining optical device 5, and the projection optical system 6 are described in the first embodiment. The white light LW may be replaced with a combination of the blue light LB (S) and the yellow light LY.

  According to the illumination device of the modified example of the first embodiment described above, the light emitting element 20A and the beam shaping element 23 that emit the blue light LB of the irradiation distribution having the longitudinal direction D1, the polarization conversion element 33, the lens array 31b, And light modulators 4B, 4G, 4R. In the illuminating device of this modification, as in the illuminating device 14A according to the first embodiment, the directions DA and DB along the outer shape of the microlens M and the longitudinal direction D1 of the light emitting surface 20e intersect each other, and the directions DA and DB And the longitudinal direction DP of the polarizing prism PP can cross each other. The plurality of microlenses M have the same longitudinal direction DM, and the longitudinal direction D1 of the light emitting surface 20e is ± (vertical width A of the microlens M / microlens M with respect to the longitudinal direction DM of the microlens M. The light emitting elements 20B and 20C can be arranged to have an inclination of the horizontal width B). Accordingly, it is possible to improve the utilization efficiency of the blue light LB and the yellow light LY emitted from the light emitting elements 20B and 20C in the lighting device, and to reduce the size of the lighting device.

  Moreover, according to the projector of the modification of 1st Embodiment, while utilizing efficiency of the white light LW emitted from 20 A of light emitting elements can be improved, size reduction can be achieved.

(Second Embodiment)
Next, an example of an illumination device and a projector according to the second embodiment of the present invention will be described. Although not shown, the illumination device and projector according to the second embodiment include the same components as those of the illumination device and projector according to the first embodiment, and the lens arrays 31a and 31b and the polarization conversion element 33A will be described next. This is replaced with the array 31c and the polarization conversion element 33B.

  However, in the second embodiment, in each of the first lens array 31a and the second lens array (lens array) 31c, each row R1, R2,..., Rm (m is a plurality of micro lenses M) adjacent to each other. (The total number of columns of the lens M, which is an arbitrary natural number of 2 or more)), in a plane orthogonal to the optical axis X, a predetermined step z with respect to the adjacent columns R1, R2,. Is attached. FIG. 9 is a schematic diagram illustrating an irradiation region of the white light LW irradiated to the second lens array 31b. As shown in FIG. 9, the steps z are arranged so that the illumination areas of the plurality of spot-like white light LW are arranged on the straight line E in a plane orthogonal to the optical axis X, that is, aligned on a straight line. It is set appropriately. Here, in the plane orthogonal to the optical axis X, an angle (narrow angle) formed by the longitudinal direction D1 of the light emitting surface 20e of the light emitting element 20A with respect to the longitudinal direction DM of the microlens M is α. The level difference z is a relational expression of tan (α) = (z / B) and α is small, so that “tan (α) == α (“ == ”on the left means almost equal (nearly equal))” Is expressed as α × B. Thus, the spot array-shaped white light LW incident on the second lens array 31b is collimated by the second lens array 31b and irradiated to the polarization conversion element 33B.

  FIG. 10 is a perspective view of the polarization conversion element 33B according to the second embodiment and an irradiation area of the spot-like white light LW irradiated to the polarization conversion element 33B. As shown in FIG. 10, at least two or more light sources among a plurality of light source images formed when the white light LW emitted from the light emitting element 20A passes through the second lens array 31b as shown in FIG. The images are arranged on a straight line E (virtual line) along the longitudinal direction DP, and all light source images are arranged on the straight line E in the second embodiment. In the polarization conversion element 33B, the longitudinal direction DP of the polarizing prism PP is inclined at an angle (narrow angle) α with respect to the longitudinal direction DM of the microlenses M of the first lens array 31a and the second lens array 31b. Have been placed. As in the first embodiment, the direction DA along the short side of the microlens M, the direction DB along the long side, and the longitudinal direction DP of the polarizing prism PP intersect each other. The spot array-shaped white light LW emitted from the polarization conversion element 33B is aligned with P-polarized light or S-polarized light.

According to the illuminating device which concerns on 2nd Embodiment demonstrated above, there exist the following effects.
The illumination device according to the second embodiment includes a light emitting element 20A having a light emitting surface 20e having a longitudinal direction D1, a polarization conversion element 33A having a plurality of polarizing prisms PP having a longitudinal direction DP, and a light emitting element 20A and a polarized light on the optical axis X. A lens array 31b provided between the conversion element 33A and having a plurality of rectangular microlenses M, and light modulation devices 4B and 4G that modulate light emitted from the light emitting element 20A and passed through the polarization conversion element 33. , 4R. In the illuminating device 14A of the first embodiment, the directions DA and DB along the outer shape of the microlens M and the longitudinal direction D1 of the light emitting surface 20e intersect each other, and the directions DA and DB and the longitudinal direction DP of the polarizing prism PP Cross each other. As a result, the utilization efficiency of the white light LW emitted from the light emitting element 20A in the lighting device can be improved, and the size of the lighting device can be reduced.

  Specifically, in the illumination device of the second embodiment, the plurality of microlenses M have longitudinal directions DM in the same direction, and the longitudinal direction D1 of the light emitting surface 20e is a microlens in a plane orthogonal to the optical axis X. It is inclined at a predetermined angle α with respect to the longitudinal direction DM of M. In addition, on the plane orthogonal to the optical axis X, the rows R1, R2,..., Rm of the plurality of microlenses M are provided with a predetermined step z with respect to the adjacent rows R1, R2,. z is expressed by (angle α × width B of the microlens M). According to the illumination device of the second embodiment, the white light LW from the light emitting element 20A is obtained by aligning the longitudinal direction M1 and the longitudinal direction DP with respect to a solid-state light source such as a white LED whose light emitting surface 20e has the longitudinal direction M1. The light loss at the polarization conversion element 33B can be reduced by passing the polarization prism PP without causing the light spot to be lost at the light shielding portion N of the polarization conversion element 33B. Further, since the irradiation areas (that is, light source images) formed on the polarization conversion element 33B are arranged on the straight line E illustrated in FIG. 9, the light transmittance in the polarization conversion element 33B can be improved.

  Further, according to the projector of the second embodiment, it is possible to increase the brightness by using the illumination device that suppresses the light loss in the polarization conversion element 33B.

(Modification of the second embodiment)
Also in the second embodiment, a modification similar to the modification of the illumination device 14 </ b> A and the projector 1 according to the first embodiment can be given. That is, the modification of the illumination device and the projector according to the second embodiment is obtained by replacing the light source optical system 41A of the illumination light generation optical system 11A with the light source optical system 41B. Also by such a modification, the same effect as 2nd Embodiment is acquired.

(Third embodiment)
Next, an example of a lighting device and a projector according to a third embodiment of the present invention will be described. Although not shown, the illumination device and projector of the third embodiment include the same components as the illumination device and projector of the first embodiment.

  FIG. 11 is a schematic diagram illustrating an irradiation region of the white light LW irradiated to the second lens array 31b in the third embodiment. As shown in FIG. 11, in the third embodiment, in the plane orthogonal to the optical axis X, the longitudinal direction D1 of the light emitting surface 20e is relative to the longitudinal direction DM in the direction DA orthogonal to the longitudinal direction DM of the microlens M. Are inclined at a predetermined angle α and deviated with a predetermined eccentricity β. The predetermined amount of eccentricity β is expressed by (angle α × width B of the microlens M), and corresponds to the distance between the center CL of the white light LW and the center CM of the microlens M. Even with such a configuration, at least two light sources among a plurality of light source images formed when the white light LW emitted from the light emitting element 20A passes through the second lens array 31b as shown in FIG. The images are arranged on a straight line E (virtual line) along the longitudinal direction DP, and all light source images are arranged on the straight line E in the third embodiment.

According to the illuminating device which concerns on 3rd Embodiment demonstrated above, there exist the following effects.
Since the illumination device of the third embodiment includes the same components as the illumination device 14A of the first embodiment, the utilization efficiency of the white light LW emitted from the light emitting element 20A in the illumination device is improved, and the illumination device Miniaturization can be achieved.

  Specifically, in the illumination device of the third embodiment, the plurality of microlenses M have longitudinal directions DM in the same direction, and the longitudinal direction D1 of the light emitting surface 20e is a microlens on the surface orthogonal to the optical axis X. It is inclined with respect to the longitudinal direction DM of M with a predetermined angle α and shifted with a predetermined eccentricity β. The amount of eccentricity β is expressed by (angle α × width B of the microlens M). According to the illumination device of the third embodiment, the white light LW from the light emitting element 20A is obtained by aligning the longitudinal direction M1 and the longitudinal direction DP with respect to a solid-state light source such as a white LED whose light emitting surface 20e has the longitudinal direction M1. The light loss at the polarization conversion element 33B can be reduced by passing the polarization prism PP without causing the light spot to be lost at the light shielding portion N of the polarization conversion element 33B. Further, since the irradiation areas (that is, light source images) formed on the polarization conversion element 33B are arranged on the straight line E illustrated in FIG. 9, the light transmittance in the polarization conversion element 33B can be improved.

  Further, according to the projector of the third embodiment, high luminance can be achieved by using an illumination device that suppresses light loss in the polarization conversion element 33A.

(Modification of the third embodiment)
Also in the third embodiment, a modification similar to the modification of the illumination device 14A and the projector 1 according to the first embodiment can be given. That is, the modification of the illumination device and the projector according to the third embodiment is obtained by replacing the light source optical system 41A of the illumination light generation optical system 11A with the light source optical system 41B. Also by such a modification, the same effect as 3rd Embodiment is acquired.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications are possible within the scope of the gist of the present invention described in the claims. Deformation / change is possible.

  For example, in each of the above-described embodiments, the projector 1 including the three light modulation devices 4R, 4G, and 4B is illustrated. However, the projector according to the present invention may be a projector that displays a color image with one light modulation device. Good. A digital mirror device may be used as the light modulation device.

DESCRIPTION OF SYMBOLS 1 ... Projector, 4B, 4G, 4R ... Light modulation element (light modulation device), 14A ... Illumination device, 20, 20A, 20B, 20C ... Light emission element, 20e ... Light emission surface, 33, 33A, 33B ... Polarization conversion element, 21b ... second lens array (lens array), D1, DM ... longitudinal direction, MA, MB ... direction (direction along the outer shape of the lens), PP ... polarizing prism

Claims (5)

A light emitting element having a light emitting surface having a longitudinal direction;
A polarization conversion element having a plurality of polarizing prisms having a longitudinal direction;
A lens array provided between the light emitting element and the polarization conversion element and having a plurality of rectangular lenses;
A light modulation element that modulates light emitted from the light emitting element and passed through the polarization conversion element;
With
The direction along the outer shape of the lens and the longitudinal direction of the light emitting surface of the light emitting element intersect each other,
The illumination device, wherein a direction along the outer shape of the lens and a longitudinal direction of a polarization prism of the polarization conversion element intersect each other. The plurality of lenses have longitudinal directions in the same direction,
The longitudinal direction of the light emitting surface is inclined with respect to the longitudinal direction of the lens corresponding to the ratio of the width of the lens in the direction parallel to the longitudinal direction of the lens to the width of the lens in the direction orthogonal to the longitudinal direction of the lens. Having
The lighting device according to claim 1. The plurality of lenses have longitudinal directions in the same direction,
In a plane perpendicular to the traveling direction of light emitted from the light emitting element, a row in which a plurality of the lenses are arranged along a direction perpendicular to the longitudinal direction of the lens is a row adjacent to the longitudinal direction of the lens. Is provided with a predetermined step, the longitudinal direction of the light emitting surface is inclined with a predetermined angle with respect to the longitudinal direction of the lens,
The predetermined step is represented by a product of the predetermined angle and a width in the longitudinal direction of the lens.
The lighting device according to claim 1. The plurality of lenses have longitudinal directions in the same direction,
In a plane orthogonal to the traveling direction of light emitted from the light emitting element, the longitudinal direction of the light emitting surface has a predetermined angle with respect to the longitudinal direction of the lens in a direction orthogonal to the longitudinal direction of the lens. Inclined and deviated with a predetermined amount of eccentricity,
The predetermined amount of eccentricity is represented by the product of the predetermined angle and the width in the longitudinal direction of the lens.
The lighting device according to claim 1. A lighting device according to any one of claims 1 to 4, comprising:
The light modulation element forms image light by modulating light emitted from the light emitting element according to image information;
A projector further comprising a projection optical system that projects the image light.

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