JP5838705B2 - Lighting device and projector - Google Patents

Description

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

FIG. 8 is a diagram schematically showing a conventional lighting device 100.
In the projector, in order to illuminate the light modulation device 200 such as a liquid crystal panel substantially uniformly, an illumination device 100 as shown in FIG. 8 is frequently used.
As shown in FIG. 8, the illuminating device 100 includes a light source device 110, a first lens array 120 that divides a light beam emitted from the light source device 110 into a plurality of partial light beams by a plurality of first small lenses 120A, and a plurality of light beams. A second lens array 130 provided with a second small lens 130A at a position geometrically corresponding to the first small lens 120A, and a plurality of partial light fluxes via the second lens array 130 to the light modulation device 200. And a superimposing lens 140 for superimposing.

Conventionally, in the illumination device 100 described above, some of the first small lenses 120A are configured by eccentric lenses, and the light amount incident on the light modulation device 200 from the + θ side and the light beam incident from the −θ side. There has been proposed a technique for reducing the difference from the amount of light flux to reduce color unevenness in a projected image and improve contrast (see, for example, Patent Document 1).
The + θ side means a side away from the optical axis Ax of the light beam emitted from the light source device 110, and the −θ side means a side close to the optical axis Ax.

9 and 10 are diagrams for explaining the function of the first small lens 120A in the conventional illumination device 100. FIG.
Specifically, FIG. 9A is a schematic view of the first lens array 120 as viewed from the light incident side. FIG. 9B shows the light intensity at each position on the first imaginary line V1 extending in the horizontal direction among the two first and second imaginary lines V1 and V2 passing through the optical axis Ax and orthogonal to each other. FIG. FIG. 9C is a diagram showing the light intensity at each position on the second virtual line V2 extending in the vertical direction.
FIG. 10A is a view similar to FIG. 9A. FIG. 10B is a view of the second lens array 130 as viewed from the light incident side.

In FIGS. 9 and 10, for convenience of explanation, if the rows are arranged horizontally and the columns are arranged vertically, the first and second small lenses 120A and 130B have 6 rows × 4 columns (light incident). As viewed from the side, the first row to the sixth row are sequentially arranged from the upper side, and the first column to the fourth column are sequentially arranged from the left side).
9A and 10B, in order to explain the function of each first small lens 120A, the letters “A” to “X” are attached in the rectangle of each first small lens 120A. doing.
Further, in FIG. 10B, in order to show the correspondence between each first small lens 120A and the position (each second small lens 130A) from which each first small lens 120A emits a partial light beam, Letters “A” to “X” are attached in the rectangle of the small lens 130A.
For example, the first small lens 120A with the letter “A” emits the divided partial light beam toward the second small lens 130A with the letter “A”.

Specifically, in the technique described in Patent Document 1, among the first small lenses 120A, the four first small lenses 121A arranged in the vicinity of the optical axis Ax are shown in FIG. In addition, the light beams are emitted toward a point symmetric with respect to the optical axis Ax with respect to the four second small lenses 131A that are arranged geometrically corresponding to the four first small lenses 121A.
Further, each of the other first small lenses 122A except for the four first small lenses 121A causes the divided partial light beams to be in a position geometrically corresponding to each of the first small lenses 122A as shown in FIG. The light is emitted toward the arranged second small lens 132A.
The geometrically corresponding position means a position where the row number and the column number match. For example, the first small lens 120A in the first column in the first row and the second small lens 130A in the first column in the first row have a geometrically corresponding positional relationship.

JP 2000-206617 A

The technique described in Patent Document 1 is based on the premise that the light intensity distribution of a light beam incident on the first lens array 120 is the first light intensity distribution shown in FIGS. 9B and 9C.
Specifically, the first light intensity distribution is a distribution that is substantially symmetric with respect to the optical axis Ax, the light intensity near the optical axis Ax is high, and the light intensity decreases as the distance from the optical axis Ax increases. .
That is, since the first light intensity distribution is a substantially symmetric distribution with respect to the optical axis Ax, in the technique described in Patent Document 1, the light intensity distribution of the light beam incident on the second lens array 130 is also the first light. The distribution is substantially the same as the intensity distribution.

By the way, the incident angle of the light beam incident on the light modulation device 200 via the second small lens 131A located on the center side is relatively small. On the other hand, the incident angle of the light beam incident on the light modulation device 200 via the second small lens 132A located on the outer peripheral side is relatively large.
That is, since the light intensity distribution of the light beam incident on the second lens array 130 is the first light intensity distribution, the light beam having a high light intensity (first light intensity) incident on the second small lens 131A located on the center side. Is incident on the light modulation device 200 at a small incident angle with respect to the light modulation device 200. On the other hand, a light beam having a low light intensity (second light intensity) incident on the second small lens 132A located on the outer peripheral side enters the light modulation device 200 at a large incident angle.
Therefore, in the technique described in Patent Document 1, when the light intensity distribution of the light beam incident on the first lens array 120 is the first light intensity distribution, the light amount of the light beam incident on the light modulation device 200 at a large incident angle is obtained. Therefore, it is possible to avoid a decrease in the contrast of the projected image.

On the other hand, when the light intensity distribution of the light beam incident on the first lens array 120 is different from the first light intensity distribution and is the second light intensity distribution, the following problems occur.
The second light intensity distribution is a substantially symmetric distribution with respect to the optical axis Ax. For example, the light intensity near the optical axis Ax is low, and the light intensity increases as the distance from the optical axis Ax increases.
In the case of such a second light intensity distribution, the light intensity distribution of the light beam incident on the second lens array 130 is also substantially the same as the second light intensity distribution, and in the case of the first light intensity distribution. Conversely, a light beam having a high light intensity (first light intensity) is incident on the second small lens 132A located on the outer peripheral side, and a light beam having a low light intensity (second light intensity) is located on the center side. The light enters the small lens 131A.
Therefore, in the technique described in Patent Document 1, when the light intensity distribution of the light beam incident on the first lens array 120 is the second light intensity distribution, the light amount of the light beam incident on the light modulation device 200 at a large incident angle is obtained. There is a problem that the contrast of the projected image is lowered.
In order to avoid a decrease in the contrast of the projected image, a configuration in which the light beam emitted from the second small lens 132A located on the outer peripheral side is shielded is also conceivable, but in this configuration, the light is emitted from the second lens array. A large amount of light of the emitted light beam is lost. That is, the brightness of the projected image is reduced.

  The objective of this invention is providing the illuminating device and projector which can improve the contrast of a projection image, without reducing the brightness of a projection image.

  An illumination device of the present invention includes a light source device, a first lens array that divides a light beam emitted from the light source device into a plurality of partial light beams, and a second lens array that is disposed on a light emission side of the first lens array. The light beam incident on the first lens array has a first light intensity portion and a second light intensity portion lower than the first light intensity, and The first lens array has a plurality of first small lenses arranged two-dimensionally, and the second lens array has a plurality of second small lenses arranged two-dimensionally, the first lens In the lens array, the first small lens on which the light beam having the first light intensity is incident is located on the outer peripheral side of the first small lens on which the light beam having the second light intensity is incident, and the first lens The first small lens on which a light beam having light intensity is incident, The first small lens that emits the emitted light beam toward the second small lens located on the center side in the second lens array and receives the light beam having the second light intensity is incident on the incident light beam. Is emitted toward the second small lens located on the outer peripheral side of the second lens array.

Here, the first light intensity means a light intensity higher than a predetermined threshold, and the second light intensity means a light intensity lower than the threshold.
In the present invention, the first small lens to which a light beam having a high light intensity (light beam having the first light intensity) is incident emits the incident light beam toward the second small lens located on the center side. On the other hand, the first small lens on which a light beam having a low light intensity (light beam having the second light intensity) is incident emits the incident light beam toward the second small lens located on the outer peripheral side.
As a result, even if the light intensity distribution of the light beam incident on the first lens array is the second light intensity distribution, the light intensity distribution of the light beam incident on the second lens array is converted to the first light intensity distribution. can do.

Therefore, if the illumination device of the present invention is mounted on a projector, the following effects can be enjoyed.
Since the light intensity distribution of the light beam incident on the second lens array becomes the first light intensity distribution, the light intensity is passed through the second small lens located on the center side of the light beam having a high light intensity (first light intensity). Low (second light intensity) luminous flux can be made incident on a light modulation device such as a liquid crystal panel through the second small lens located on the outer peripheral side. In other words, since the amount of the light beam incident on the light modulation device at a large incident angle can be reduced, the contrast of the projection image can be improved without reducing the brightness of the projection image.

  In the illuminating device of the present invention, the first lens array and the second lens array are viewed from the direction along the optical axis of the light beam emitted from the light source device, and two imaginary lines that are orthogonal to each other through the optical axis. When the first small lens is virtually divided into four regions by the above, the first small lens is configured to cause the incident light beam to be incident on the second lens array geometrically corresponding to the region including the first small lens. It is preferable that the light is emitted toward the second small lens in the region.

By the way, the second lens in the second region different from the first region in the second lens array geometrically corresponding to the first region from the first small lens included in the first region among the four regions described above. When configured to emit a light beam toward the small lens, there are the following problems.
That is, when configured as described above, it is necessary to increase the degree of eccentricity of the first small lens, and it is difficult to easily manufacture the first lens array.
In addition, when the degree of eccentricity of the first small lens is increased, it is difficult to cause the light beam to enter the desired second small lens from the first small lens, and other different from the desired second small lens. The light beam also enters the second small lens. For this reason, it is impossible to effectively irradiate the light modulation device such as a liquid crystal panel with the light flux, and the brightness of the projected image is reduced.

In contrast, in the present invention, the first small lens directs the incident light beam to the second small lens in the region in the second lens array that geometrically corresponds to the region including the first small lens. And exit.
Accordingly, it is not necessary to increase the degree of eccentricity in the first small lens, and the first lens array can be easily manufactured.
In addition, since it is not necessary to increase the degree of eccentricity of the first small lens, the light beam can be incident only from the first small lens to the desired second small lens. That is, it is possible to effectively irradiate a light beam to a light modulation device such as a liquid crystal panel, and to avoid a reduction in brightness of a projected image.

The projector of the present invention is a projector including an illumination device, a light modulation device that modulates a light beam emitted from the illumination device, and a projection optical device that projects the light beam modulated by the light modulation device. The illumination device is the illumination device described above.
In the present invention, since the projector includes the illumination device described above, the projector can enjoy the same operations and effects as the illumination device described above.

  In the projector according to the aspect of the invention, the illumination device includes a superimposing lens that is disposed on a light emitting side of the second lens array and superimposes the plurality of partial light beams via the second lens array. A light control device that is disposed in an optical path of a light beam from the first lens array to the superimposing lens and changes an area of a light passage region that allows the light beam to pass through the light control device; It is preferable to provide a pair of light shielding plates that are arranged symmetrically about the optical axis of the emitted light beam and move so that the ends facing each other are closely separated from each other.

In the present invention, the light control device disposed in the optical path of the light beam from the first lens array to the superimposing lens is arranged symmetrically about the optical axis, and moves so that the ends facing each other are close to each other. A pair of light shielding plates.
Thus, for example, if the pair of light shielding plates are positioned at positions where the end portions facing each other are separated from each other, the light intensity distribution of the light beam incident on the second lens array as described above becomes the first light intensity distribution. Therefore, the light beam emitted from the second small lens located on the outer peripheral side can be shielded by the pair of light shielding plates. That is, since the light beam emitted from the second small lens located on the outer peripheral side is a light beam that is incident on the light modulation device such as a liquid crystal panel at a large incident angle, by shielding the light beam, The contrast can be further improved.
In addition, if the pair of light shielding plates are moved from a position where each end facing each other to a position close to each other, the light intensity distribution of the light beam incident on the second lens array becomes the first light intensity distribution. The brightness of the projected image can be appropriately adjusted without being shielded from a light beam having a high light intensity (first light intensity).

  In the projector according to the aspect of the invention, the illumination device includes a superimposing lens that is disposed on a light emitting side of the second lens array and superimposes the plurality of partial light beams via the second lens array. It is preferable that a diaphragm device is provided in the optical path of the light beam from the first lens array to the superimposing lens and shields the light beam on the side separated from the optical axis of the light beam emitted from the light source device.

In the present invention, the diaphragm device disposed in the optical path of the light beam from the first lens array to the superimposing lens blocks the light beam on the side away from the optical axis.
As a result, the light intensity distribution of the light beams incident on the second lens array becomes the first light intensity distribution as described above, so that the light beams emitted from the second small lens located on the outer peripheral side are reduced by the diaphragm device. Can be shielded from light. That is, by shielding the light flux, the contrast of the projected image can be further improved as described above.
Further, since the light beam emitted from the second small lens located on the outer peripheral side is a light beam having a low light intensity (second light intensity), the contrast of the projection image can be further increased without reducing the brightness of the projection image. Can be improved.

1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment. The figure which shows the light intensity distribution of the light beam which injects into the 1st lens array in 1st Embodiment. The figure for demonstrating the function of the 1st small lens in 1st Embodiment. The figure which shows typically the structure of the light modulation apparatus in 1st Embodiment. The figure which shows typically the structure of the aperture_diaphragm | restriction apparatus in 2nd Embodiment. The figure which shows the modification of each embodiment. The figure which shows the modification of each embodiment. The figure which shows the conventional illuminating device typically. The figure for demonstrating the function of the 1st small lens in the conventional illuminating device. The figure for demonstrating the function of the 1st small lens in the conventional illuminating device.

[First embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a diagram illustrating a schematic configuration of the projector 1.
The projector 1 projects an image and displays a projected image on a screen (not shown).
As shown in FIG. 1, the projector 1 includes an optical unit 3 that is housed in the exterior housing 2.

[Configuration of optical unit]
As shown in FIG. 1, the optical unit 3 includes an optical component housing 4 and a projection lens 5 as a projection optical device supported by the optical component housing 4.
As shown in FIG. 1, the optical component housing 4 includes an illumination device 6, a color separation optical device 31 having dichroic mirrors 311 and 312, and a reflection mirror 313, an incident side lens 321, a relay lens 323, and Relay optical device 32 having reflection mirrors 322 and 324, three incident side polarizing plates 33, three liquid crystal panels 34 as light modulating devices, three outgoing side polarizing plates 35, and a cross as a color combining optical device The dichroic prism 36 and the light control device 7 are accommodated.
And each said members 31-36 are located in the predetermined position with respect to the optical axis Ax of the light beam radiate | emitted from the illuminating device 6 inside the housing | casing 4 for optical components, as shown in FIG.

With the configuration described above, the light beam emitted from the illumination device 6 is separated into three color lights of red (R), green (G), and blue (B) by the color separation optical device 31. Each separated color light is modulated by each liquid crystal panel 34. The modulated color lights are combined by the prism 36 and projected onto the screen by the projection lens 5.
In addition, since each member 31-36,5 mentioned above is a structure used with a general projector, below, only the structure of the illuminating device 6 and the light control apparatus 7 is demonstrated.

[Configuration of lighting device]
As shown in FIG. 1, the illumination device 6 includes a light source device 61 having a light source lamp 611 and a reflector 612, a first lens array 62, a second lens array 63, a polarization conversion element 64, and a superimposing lens 65. Prepare.
With the configuration described above, the light beam emitted from the light source device 61 is divided into a plurality of partial light beams by the first lens array 62. Further, the divided partial light beams enter the polarization conversion element 64 via the second lens array 63 and are converted into substantially one type of linearly polarized light. The plurality of partial light fluxes converted into substantially one type of linearly polarized light are superimposed on the liquid crystal panel 34 via the superimposing lens 65. That is, the illumination device 6 illuminates the liquid crystal panel 34 substantially uniformly.
The members 61, 64, and 65 described above are configurations used in a general projector, and therefore only the configurations of the first and second lens arrays 62 and 63 will be described below.

[Configuration of the first lens array]
FIG. 2 is a diagram showing the light intensity distribution of the light beam incident on the first lens array 62.
Specifically, FIG. 2A is a schematic view of the first lens array 62 viewed from the light incident side. FIG. 2B shows the light intensity at each position on the first virtual line V1 extending in the horizontal direction, out of the two first and second virtual lines V1 and V2 that pass through the optical axis Ax and are orthogonal to each other. FIG. FIG. 2C is a diagram showing the light intensity at each position on the second virtual line V2 extending in the vertical direction.
In FIG. 2A, for convenience of explanation, in order to explain the function of each of the plurality of first small lenses 62A described later in the first lens array 62, “A” is shown in the rectangle of each first small lens 62A. ~ The letter “X” is attached.
In this embodiment, the light intensity emitted from the light source device 61 and incident on the first small lens 62A around the optical axis Ax in the inner range in the first lens array 62 is relatively low (second light intensity), and the outer peripheral side. The light intensity distribution of a light beam having a relatively high light intensity (first light intensity) incident on the first small lens 62A in FIG. Further, in the second lens array 63, the light intensity incident on the second small lens 63A around the optical axis Ax in the inner range is relatively high (first light intensity), and incident on the second small lens 63A on the outer peripheral side. The light intensity distribution of a light beam having a relatively low light intensity (second light intensity) is defined as a first light intensity distribution.
Specifically, as shown in FIG. 2, the second light intensity distribution is a substantially symmetric distribution with respect to the optical axis Ax, the light intensity near the optical axis Ax is low (second light intensity), and the optical axis The light intensity increases as the distance from Ax increases (first light intensity), and the light intensity decreases (second light intensity) as the distance further increases. As shown in FIG. 4, the first light intensity distribution is a distribution that is substantially symmetrical with respect to the optical axis Ax, has a high light intensity near the optical axis Ax (first light intensity), and is separated from the optical axis Ax. Accordingly, the light intensity is low (second light intensity). The light intensity is set as appropriate from a light intensity distribution emitted from the light source device 61 and incident on the incident surface of the first lens array 62, and the light intensity equal to or higher than the predetermined threshold is defined as the first light intensity. The light intensity below the predetermined threshold is set as the second light intensity.

In the first lens array 62, as shown in FIG. 2A, first small lenses 62A having a substantially rectangular outline as viewed from the direction along the optical axis Ax are arranged in a matrix.
In the present embodiment, when the rows are arranged in a row and the columns are arranged in a row, the plurality of first small lenses 62A have 6 rows × 4 columns (light incidence as shown in FIG. 2A). As viewed from the side, the first row to the sixth row are sequentially arranged from the upper side, and the first column to the fourth column are sequentially arranged from the left side).
Each first small lens 62 </ b> A divides the light beam emitted from the light source device 61 into a plurality of partial light beams, and condenses each partial light beam in the vicinity of the second lens array 63.
The function of each first small lens 62A (to which position of the second lens array 63 the partial light beam is emitted) will be described later.

[Configuration of the second lens array]
The second lens array 63 is disposed on the light exit side of the first lens array 62, and similarly to the first lens array 62, the second small lens 63A having a substantially rectangular outline when viewed from the direction along the optical axis Ax. Are arranged in a matrix.
In the present embodiment, like the first lens array 62, the plurality of second small lenses 63A has 6 rows × 4 columns (first row to sixth row in order from the upper side when viewed from the light incident side, and sequentially from the left side. The first column to the fourth column are arranged in a matrix (see FIG. 3B).
The plurality of second small lenses 63A have a function of aligning the principal rays of the partial light beams emitted from the first lens array 62 in parallel with the optical axis Ax.

[Function of the first small lens]
FIG. 3 is a diagram for explaining the function of the first small lens 62A.
Specifically, FIG. 3A is the same diagram as FIG. FIG. 3B is a schematic view of the second lens array 63 viewed from the light incident side.
In FIG. 3B, in order to show the correspondence between each first small lens 62A and the position where each first small lens 62A emits a partial light beam (each second small lens 63A), Letters “A” to “X” are attached in the rectangle of the small lens 63A.
For example, as shown in FIG. 3, the first small lens 62A with the letter “A” emits the divided partial light beam toward the second small lens 63A with the letter “A”. .

Each first small lens 62A is composed of an eccentric lens whose optical axis is deviated from the position of the geometric center of each lens, and emits the divided partial light beams toward the positions shown below.
In the following, for convenience of explanation, the first and second lens arrays 62 and 63 are virtually divided into four regions by the first and second virtual lines V1 and V2 (FIGS. 2 and 3), respectively. In the first lens array 62, among the four regions virtually divided, in FIG. 3A, the upper left region is the incident side first region 621, and the upper right region is the incident side second region 622. The lower left region is referred to as an incident side third region 623, and the lower right region is referred to as an incident side fourth region 624. Further, in the second lens array 63, the regions corresponding geometrically to the incident side first to fourth regions 621 to 624 are defined as emission side first to fourth regions 631 to 634 (FIG. 3B). ).

First, each of the first small lenses 62A arranged in the first and second rows has the divided partial light beams at positions geometrically corresponding to the respective first small lenses 62A as shown in FIG. With respect to each second small lens 63A (each second small lens 63A arranged in the first and second rows), the second small lenses 63A are positioned symmetrically with respect to the boundary B12 of the first and second rows. Exit toward.
For example, as shown in FIG. 3, the first small lens 62A in the first row and the first column in the third row has the divided partial light fluxes in the third row, which is a line symmetric with respect to the boundary B12. The light is emitted toward the second small lens 63A in the second row.
Similarly, each of the first small lenses 62A arranged in the third and fourth rows also has the divided partial light beams arranged at positions corresponding to the respective first small lenses 62A geometrically. With respect to the second small lens 63A (each second small lens 63A arranged in the third and fourth rows), the light is emitted toward a line-symmetrical position with respect to the boundary B34 of the third and fourth rows.

As described above, in the present embodiment, as illustrated in FIG. 2 or FIG. 3, the first small lens 62A (for example, a light beam having a high light intensity (a light beam having a first light intensity equal to or greater than a predetermined threshold) is incident (for example, , A first small lens 62A) with a letter “D” is a second small lens 63A (for example, a second small lens with a letter “D”) positioned on the center side of the divided partial luminous flux. 63A).
On the other hand, the first small lens 62A (for example, the first small lens 62A with the letter “A”) into which a light beam having a low light intensity (a light beam having a second light intensity lower than the predetermined threshold) is incident is provided. The divided partial light beams are emitted toward the second small lens 63A (for example, the second small lens 63A with the letter “A”) positioned on the outer peripheral side.
Moreover, in this embodiment, as shown in FIG. 3, each 1st small lens 62A is divided into the 2nd in the area | region 631-634 in the area | region 631-634 geometrically corresponding to the area | region 621-624 containing self. The light is emitted toward the small lens 63A.

[Configuration of light control device]
FIG. 4 is a diagram schematically illustrating the configuration of the light control device 7.
Specifically, FIG. 4A is a diagram of the dimmer 7 viewed from the side, and FIG. 4B is a diagram illustrating the light intensity distribution of a light beam incident on the second lens array 63.
As shown in FIG. 4, the light control device 7 is disposed in the optical path of the light beam from the second lens array 63 to the polarization conversion element 64, and changes the area of the light passage area Ar through which the light beam passes.
As shown in FIG. 4, the light control device 7 includes a pair of light shielding plates 71 arranged symmetrically with respect to a horizontal plane Fh passing through the optical axis Ax.

The pair of light-shielding plates 71 are controlled by a control device (not shown), and driving means (not shown) such as a motor, and a transmission mechanism (not shown) such as a gear for transmitting a driving force generated by the motor or the like. It is comprised so that rotation is possible.
More specifically, the pair of light shielding plates 71 are configured to be rotatable so that the ends facing each other are close to each other and are also close to and separated from the polarization conversion element 64.
As shown in FIG. 4, the light control device 7 rotates the pair of light shielding plates 71 so that a light beam can pass through the light passing area Ar (between the ends of the pair of light shielding plates 71 facing each other). ) To adjust the light quantity of the light beam incident on the polarization conversion element 64 (liquid crystal panel 34).

The first embodiment described above has the following effects.
In the present embodiment, in the first lens array 62, each first small lens 62A is formed of an eccentric lens as described above.
As a result, even if the light intensity distribution of the light beam incident on the first lens array 62 is the second light intensity distribution (FIGS. 2B and 2C), it is incident on the second lens array 63. The light intensity distribution of the luminous flux to be converted can be converted into the first light intensity distribution (FIG. 4B).
That is, since the light intensity distribution of the light beam incident on the second lens array 63 becomes the first light intensity distribution, the light beam having a high light intensity (first light intensity) is passed through the second small lens 63A located on the center side. Thus, a light beam having a low light intensity (second light intensity) can be made incident on the liquid crystal panel 34 via the second small lens 63A located on the outer peripheral side.
For this reason, the light quantity of the light beam incident on the liquid crystal panel 34 at a large incident angle can be reduced.
Therefore, the contrast of the projected image can be improved without reducing the brightness of the projected image.

The first small lens 62A emits the divided partial light beam toward the second small lens 63A in the regions 631 to 634 geometrically corresponding to the regions 621 to 624 including the first small lens 62A. .
Thus, it is not necessary to increase the degree of eccentricity in the first small lens 62A, and the first lens array 62 can be easily manufactured.
Further, since it is not necessary to increase the degree of eccentricity of the first small lens 62A, the light beam can be incident only from the first small lens 62A to the desired second small lens 63A, which is effective for the liquid crystal panel 34. Can be irradiated with a luminous flux. For this reason, it can avoid that the brightness of a projection image reduces.

The light control device 7 is disposed in the optical path of the light beam from the second lens array 63 to the polarization conversion element 64. The light control device 7 includes a pair of light shielding plates 71 that are arranged symmetrically about the optical axis Ax and rotate so that the ends facing each other are closely separated from each other.
Thus, for example, if the pair of light shielding plates 71 are positioned at positions where the end portions facing each other are separated from each other, the light intensity distribution of the light beam incident on the second lens array 63 is the first light intensity as described above. Because of the distribution, the light beam emitted from the second small lens 63 </ b> A located on the outer peripheral side can be shielded by the pair of light shielding plates 71. That is, since the light beam emitted from the second small lens 63A located on the outer peripheral side is a light beam that is incident on the liquid crystal panel 34 at a large incident angle, the contrast of the projected image is further improved by shielding the light beam. Can be improved.
Further, if the pair of light shielding plates 71 is rotated from a position where the opposing end portions are separated from each other to a close position, the light intensity distribution of the light beam incident on the second lens array 63 becomes the light of the first light intensity distribution. Since the light is shielded from the low intensity (second light intensity) portion, the light of the high light intensity (first light intensity) is not shielded immediately after the start of light shielding, and the brightness of the projected image is appropriately adjusted. Can be adjusted.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described based on drawing.
In the following description, the same configurations and the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
FIG. 5 is a diagram schematically showing the configuration of the diaphragm device 8 in the second embodiment.
Specifically, FIG. 5A is a view of the diaphragm device 8 viewed from the side, and FIG. 5B is a view similar to FIG. 4B.
The present embodiment differs from the first embodiment only in that a diaphragm device 8 shown in FIG. 5 is provided instead of the light control device 7. Other configurations are the same as those in the first embodiment.

As shown in FIG. 5, the aperture device 8 is disposed in the optical path of the light beam from the second lens array 63 to the polarization conversion element 64, and shields the light beam on the side away from the optical axis Ax.
Specifically, the diaphragm device 8 includes a circular opening 81 that allows a light beam to pass therethrough, allows the light beam to pass through the opening 81, and blocks the light beam at a portion other than the opening 81.
That is, in the present embodiment, by providing the diaphragm device 8, unlike the first embodiment, the area of the light passage region Ar is fixed.

According to the second embodiment described above, there are the following effects in addition to substantially the same effects as those of the first embodiment.
In the present embodiment, the diaphragm device 8 is disposed in the optical path of the light beam from the second lens array 63 to the polarization conversion element 64, and shields the light beam on the side away from the optical axis Ax.
As a result, as in the first embodiment, the light intensity distribution of the light beam incident on the second lens array 63 is the first light intensity distribution (FIG. 5B), so The light beam emitted from the second small lens 63 </ b> A can be shielded by the diaphragm device 8. That is, by blocking the light flux, the contrast of the projected image can be further improved as in the first embodiment.
In addition, since the light beam emitted from the second small lens 63A located on the outer peripheral side is a light beam having a low light intensity (second light intensity), the contrast of the projection image is reduced without reducing the brightness of the projection image. Further improvement can be achieved.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
6 and 7 are diagrams showing modifications of the above-described embodiments.
Specifically, FIGS. 6 and 7 are diagrams corresponding to FIG. 3 and illustrating the function of the first small lens 62A.
In each of the embodiments, the function of each first small lens 62A is not limited to the function shown in FIG. That is, as a function of each first small lens 62A, a light beam having a high light intensity (first light intensity) is directed toward the second small lens 63A on the center side, and a light beam having a low light intensity (second light intensity) is arranged on the outer periphery. Any other function, for example, the function shown in FIG. 6 or 7 may be used as long as it has a function of emitting light toward the second small lens 63A on the side.

For example, each first small lens 62A shown in FIG. 6 has the following function.
First, each first small lens 62A arranged in the first and third rows has each second small lens disposed at a position geometrically corresponding to each of the first small lenses 62A. With respect to the lens 63A (each second small lens 63A arranged in the first and third rows), it is located between the first and third rows and is based on a boundary B13 parallel to the first virtual line V1. The light is emitted toward a line-symmetric position.
In addition, each first small lens 62A arranged in the fourth row and the sixth row has each second light beam arranged at a position geometrically corresponding to each of the first small lenses 62A. For the small lens 63A (the second small lenses 63A arranged in the fourth row and the sixth row), a boundary B46 located between the fourth and sixth rows and parallel to the first virtual line V1 is provided. The light is emitted toward a position that is line symmetric as a reference.
Each of the first small lenses 62A arranged in the second row and the fifth row has the divided partial light beams arranged in positions corresponding to the respective first small lenses 62A geometrically. It emits toward the small lens 63A.

Further, for example, each first small lens 62A shown in FIG. 7 has the following function.
First, each first small lens 62A arranged in the second and third rows has each second small lens disposed at a position geometrically corresponding to each first small lens 62A. The light is emitted toward the lens 63A (second small lenses 63A arranged in the second and third rows) toward a line-symmetrical position with respect to the boundary B23 of the second and third rows.
In addition, each first small lens 62A arranged in the fourth row and the fifth row has each second partial beam arranged at a position geometrically corresponding to each first small lens 62A. With respect to the small lens 63A (the second small lenses 63A arranged in the fourth row and the fifth row), the light is emitted toward a line-symmetrical position with respect to the boundary B45 of the fourth and fifth rows.
Each of the first small lenses 62A arranged in the first row and the sixth row has each second light beam arranged at a position geometrically corresponding to each of the first small lenses 62A. It emits toward the small lens 63A.

6 and 7 as described above, as can be seen with reference to FIGS. 2B and 2C, each first small lens 62A has a light intensity. A high (first light intensity) light beam is emitted toward the second small lens 63A located on the center side, and a low (second light intensity) light beam is emitted toward the second small lens 63A located on the outer peripheral side. .
Moreover, even if it is the structure which has a function shown in FIG.6 and FIG.7, each 1st small lens 62A is the 2nd small lens in the area | region 631-634 geometrically corresponding to the area | regions 621-624 containing self. The light is emitted toward 63A.

  In each of the above embodiments, the light control device 7 and the diaphragm device 8 are disposed in the optical path of the light flux from the second lens array 63 to the polarization conversion element 64. However, the present invention is not limited to this, and the first lens array 62 is not limited thereto. As long as it is disposed in the optical path of the light beam from the superimposing lens 65 to the superimposing lens 65, it may be disposed at any position.

In each of the embodiments described above, the first and second lens arrays 62 and 63 have a configuration in which the first and second small lenses 62A and 63A are arranged in a matrix of 4 rows × 6 columns. Alternatively, a configuration in which the matrix is arranged in other forms such as 6 rows × 6 columns may be used.
In the first embodiment, in the light control device 7, the pair of light shielding plates 71 are configured to rotate. However, the present invention is not limited to this. That is, the pair of light shielding plates 71 is configured to move linearly instead of rotating as long as the light shielding plates 71 are arranged symmetrically about the optical axis Ax and move so that the ends facing each other are closely separated from each other. May be adopted.
In each of the embodiments described above, the transmissive liquid crystal panel 34 is used as the light modulation device. You may adopt.

  The present invention can be used for projectors used in presentations, home theaters, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 5 ... Projection lens (projection optical device), 6 ... Illumination device, 7 ... Light control device, 8 ... Diaphragm device, 34 ... Liquid crystal panel (light modulation device) , 61... Light source device, 62... First lens array, 62 A... First small lens, 63... Second lens array, 63 A. Lens, 71 ... Light shielding plate, 621 to 624 ... First to fourth areas on the incident side, 631 to 634 ... First to fourth areas on the emission side, Ax ... Optical axis of illumination, V1, V2 ... first and second virtual lines.

Claims (5)

An illumination device comprising: a light source device; a first lens array that divides a light beam emitted from the light source device into a plurality of partial light beams; and a second lens array disposed on a light emission side of the first lens array. There,
The light beam incident on the first lens array has a first light intensity portion and a second light intensity portion lower than the first light intensity,
The first lens array has a plurality of first small lenses arranged two-dimensionally,
The second lens array has a plurality of second small lenses arranged two-dimensionally,
In the first lens array, the first small lens on which the light beam having the first light intensity is incident is located on the outer peripheral side from the first small lens on which the light beam having the second light intensity is incident,
The first small lens the light beam having the first light intensity is incident, and emitted toward the entrance Isa light beam before Symbol second small lenses,
The first small lens the light beam having the second light intensity is incident, and emitted toward the entrance Isa light beam before Symbol second small lenses,
In the second lens array, the second small lens on which the light beam having the first light intensity is incident is located closer to the center than the second small lens on which the light beam having the second light intensity is incident. A lighting device characterized by the above. The lighting device according to claim 1.
When the first lens array and the second lens array are viewed from the direction along the optical axis of the light beam emitted from the light source device, virtual regions are respectively formed in four regions by two virtual lines passing through the optical axis and orthogonal to each other. If you divide
The first small lens is
The illuminating device, wherein the incident light beam is emitted toward the second small lens in the region in the second lens array geometrically corresponding to the region including the first small lens. A projector comprising: an illumination device; a light modulation device that modulates a light beam emitted from the illumination device; and a projection optical device that projects the light beam modulated by the light modulation device,
The lighting device includes:
The projector according to claim 1, wherein the projector is the lighting device according to claim 1. The projector according to claim 3.
The lighting device includes:
A superimposing lens that is disposed on the light exit side of the second lens array and superimposes the plurality of partial light fluxes via the second lens array;
The projector is
A light control device that is arranged in an optical path of a light beam from the first lens array to the superimposing lens and changes an area of a light passage region that allows the light beam to pass through;
The light control device is:
A projector comprising: a pair of light shielding plates that are symmetrically arranged around the optical axis of a light beam emitted from the light source device and that move so that end portions facing each other are closely separated from each other. The projector according to claim 3.
The lighting device includes:
A superimposing lens that is disposed on the light exit side of the second lens array and superimposes the plurality of partial light fluxes via the second lens array;
The projector is
A projector comprising: an aperture device that is disposed in an optical path of a light beam from the first lens array to the superimposing lens and shields a light beam on a side separated from an optical axis of the light beam emitted from the light source device. .

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