JP2018060055A - Luminaire and projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent decrease in light utilization efficiency of a luminaire due to an increased divergence angle of light entering a lens.SOLUTION: A luminaire 10 comprises: a light supply part 30 including a plurality of unit light emission parts 35 each having an optical fiber 32; an afocal optical system 40 reducing optical path widths of beams la, lb, lc from the light supply part 30; a scanner 50 continuously changing the direction of travel of the beams la, lb, lc from the afocal optical system 40; a first lens array 60 to which the beam from the scanner 50 enters so as to be scanned; a second lens array 70 arranged opposite the first lens array 60; and a deflection element 80 arranged opposite the second lens array 70 and changing the direction of travel of the beam from the second lens array 70. A capture angle θ[°] of a first unit lens 61 included in the first lens array 60, a divergence angle α[°] of the beam advancing from the afocal optical system 40, and a scan angle β[°] of the scanner 50 satisfies the relation of α+β≤θ.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present disclosure relate to an illumination device that illuminates an illuminated area using light emitted from a plurality of optical fibers. The embodiment of the present disclosure also relates to a projection device that uses such an illumination device.

  In an illumination device that emits coherent light such as laser light, there is a problem of speckle generation. A speckle is a speckled pattern that appears when a scattering surface is irradiated with coherent light such as laser light. For example, speckle is observed as spot-like luminance unevenness (brightness unevenness) when it occurs on the screen, and causes a physiological adverse effect on the observer. As a countermeasure against speckle, in the illumination device disclosed in Patent Document 1, the incident angle of the illumination light on the scattering surface changes over time. For this reason, speckles on the scattering surface generated by the diffusion of coherent light are superimposed and averaged over time, and become inconspicuous.

  As a specific configuration, the illumination device disclosed in Patent Document 1 includes a light source that emits light, a scanning device, a first lens array, a second lens array, and a condenser lens along an optical path. Have in order. The scanning device irradiates light from the light source onto the first lens array from a certain direction so as to scan the first lens array. The light applied to the unit lenses included in the first lens array is then incident on the corresponding unit lenses of the second lens array, and is then collected by the condenser lens in the illuminated area. In the illuminating device disclosed in Patent Document 1, the emission position of the light from the condenser lens toward the illuminated area changes over time. As a result, the illuminated area is illuminated from various directions corresponding to each area on the optical element, thereby making speckles inconspicuous.

JP 2012-237813 A

  By the way, a high-power illumination device usually includes a plurality of light sources. In many cases, light emitted from a plurality of light sources is guided by an optical fiber, and then synthesized by an optical system using a lens (uniform optical system).

  However, the light emitted from the optical fiber is diverging. Therefore, even if the profile of light emitted from each optical fiber is adjusted, the adjusted light becomes light having a divergence angle in accordance with Etendue's conservation law. As a result, if the divergence angle of the divergent light after adjustment is too large, when entering the optical system further downstream of the optical path, it is also assumed that the light enters from a direction equal to or greater than the taking-in angle of the lens included in the optical system. . Such light is not captured as desired by the optical system and cannot be used effectively. As a result, the light use efficiency in the lighting device is deteriorated. Further, the light that could not be captured becomes stray light or the like, which can adversely affect the illumination of the exposed area.

  Furthermore, in the illuminating device using the scanning device that changes the optical path over time for the purpose of reducing speckle noise, such as the illuminating device disclosed in Patent Document 1, it is particularly incident on the first lens array. As a result, the angle distribution of the light increases and the light use efficiency decreases.

  In addition, an afocal optical system may be used to reduce the size of the illumination device. When the optical path width (spot diameter) is reduced by an afocal optical system, the divergence angle of light incident on the lens is increased due to Etendue's conservation law, and the use efficiency of light in the illumination device is further reduced.

  An embodiment of the present disclosure has been made in consideration of the above points, and aims to improve light use efficiency in a (high output) illumination device that uses light from a plurality of optical fibers. To do.

A lighting device according to an embodiment of the present disclosure includes:
A light supply unit including a plurality of unit light emitting units having an optical fiber and a lens for suppressing a divergence angle of light emitted from the optical fiber;
An afocal optical system that reduces the optical path width of the light from the light supply unit;
A scanning device that changes the traveling direction of light from the afocal optical system over time;
A first lens array incident so that light from the scanning device scans;
A second lens array disposed opposite the first lens array;
A deflecting element that changes a traveling direction of light from the second lens array disposed to face the second lens array;
The light incident on a certain area of the first lens array and the light incident on another area different from the certain area of the first lens array are respectively the first lens array and the second lens. The optical path is adjusted by the array and the deflection element, and at least partially overlaps the area,
The first lens array includes a plurality of first unit lenses,
The second lens array includes a plurality of second unit lenses provided corresponding to the first unit lenses of the first lens array,
The capturing angle θ [°] of the first unit lens, the divergence angle α [°] of the light that has advanced from the afocal optical system, and the scanning angle β [°] of the scanning device satisfy the following relationship: .
α + β ≦ θ

  In the illuminating device according to the embodiment of the present disclosure, the principal point of each second unit lens may be located on the rear focal point of the first unit lens corresponding to the second unit lens.

  In the illumination device according to the embodiment of the present disclosure, the lens that suppresses the divergence angle of the light may be a collimator lens.

In addition, a projection device according to an embodiment of the present disclosure includes:
A lighting device according to an embodiment of the present disclosure as described above;
A spatial light modulator illuminated by light from the illumination device.

  According to the present disclosure, in a lighting device that uses light from a plurality of optical fibers, light use efficiency can be improved.

FIG. 1 is a diagram for explaining an embodiment of the present disclosure, and is a diagram for explaining an example of a projection device and a projection display device. FIG. 2 is a diagram showing a scanning device included in the projection device of FIG. FIG. 3 is a diagram for explaining the change over time in the traveling direction of the light emitted from the scanning device shown in FIG. FIG. 4 is a diagram showing a modification of the scanning device shown in FIG. FIG. 5 is a diagram for explaining the change over time in the traveling direction of the light emitted from the scanning device shown in FIG.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  A projection display device 1 shown in FIG. 1 includes a screen 2 and a projection device 3 that projects image light. The projection device 3 includes an illumination device 10 that illuminates the illuminated region LZ located on the virtual plane, a spatial light modulator 20 that is arranged at a position overlapping the illuminated region LZ, and is illuminated by light from the illumination device 10; A projection optical system 25 that projects light from the spatial light modulator 20 onto the screen 2. That is, in one embodiment described here, the illumination device 10 is incorporated in the projection device 3 as an illumination device for illuminating the spatial light modulator 20. And this illumination device 10 can illuminate the to-be-illuminated area | region LZ brightly, and the device for improving the utilization efficiency of light is made | formed.

  First, the illumination device 10 will be described. As shown in FIG. 1, the illumination device 10 includes a light supply unit 30 that emits light, an afocal optical system 40 that acts on the light emitted from the light supply unit 30, a scanning device 50, and a first lens array. 60, a second lens array 70, and a deflection element 80. Among these, the first lens array 60, the second lens array 70, and the deflecting element 80 constitute an optical path adjusting optical system 55 that diffuses or condenses incident light in the illuminated area. In the example shown in FIG. 1, the afocal optical system 40, the scanning device 50, the first lens array 60, the second lens array 70, and the deflection element 80 are arranged in this order along the optical path of light from the light supply unit 30. And act on light in this order.

  The light supply unit 30 includes a plurality of unit light emitting units 35 each having an optical fiber 32 and a lens 33 that suppresses a divergence angle of light emitted from the optical fiber 32. In the example shown in FIG. 1, the optical fiber 32 guides light incident from a plurality of light source units that oscillate laser light. Each optical fiber 32 may guide light oscillated by a single laser light source, or may guide light oscillated by a plurality of laser light sources. In the example shown in FIG. 1, the lens 33 that suppresses the divergence angle of the light emitted from the optical fiber 32 is a collimating lens. In the light supply unit 30 illustrated in FIG. 1, the plurality of unit light emitting units 35 may be provided independently, or may be a light source module in which the plurality of unit light emitting units 35 are arranged side by side on a common substrate. May be. As an example, the light supply unit 30 includes a first unit light emitting unit 35a that emits light la in the red emission wavelength range, a second unit light emitting unit 35b that emits light lb in the green emission wavelength range, and blue And a third unit light emitting part 35c for emitting light lc in the emission wavelength region. According to this example, it is possible to generate illumination lights of various colors including white illumination light by superimposing the three lights la, lb, and lc emitted by the plurality of unit light emitting portions 35a, 35b, and 35c. Can do.

  Next, the afocal optical system 40 will be described. The afocal optical system 40 reduces the optical path width of the light la, lb, lc from the light supply unit 30. In particular, as shown in FIG. 1, the afocal optical system 40 used in the present embodiment reduces the entire optical path width W1 of a plurality of incident light beams la, lb, and lc, so that the light having the optical path width W2 as a whole is reduced. It is an optical system that emits light as la, lb, and lc. In one specific example shown in FIG. 1, the afocal optical system 40 includes a first lens 41 arranged on the upstream side in the optical path of the light la, lb, lc from the light supply unit 30, and a downstream side in the optical path. And a second lens 42 disposed on the surface.

  As shown in FIG. 1, the first lens 41 and the second lens 42 are arranged so that their optical axes are located on the same straight line. In particular, in the specific example shown in FIG. 1, the first lens 41 is a convex lens, the second lens 42 is a concave lens, and the rear focal point of the first lens 41 coincides with the front focal point of the second lens 42. Is arranged. In this manner, the illustrated afocal optical system 40 reduces the entire optical path width W1 of the plurality of lights la, lb, and lc incident on the first lens 41 to the optical path width W2, and the lights la, lb, and lc. Can be emitted from the second lens 42 in a state where the optical axes lax, lbx, lcx are parallel to each other. In the illuminating device 10 shown in FIG. 1, by reducing the optical path width of the light la, lb, lc by the afocal optical system 40, the dimensions of the optical systems positioned further downstream of the optical path of the light la, lb, lc. To make it smaller.

  On the other hand, from Etendue's conservation law, the reduction ratio of the optical path width of the light la, lb, lc from the light supply unit 30 in the afocal optical system 40, that is, the ratio between the optical path width W1 and the optical path width W2 increases. It is known that the divergence angle α [°] of the light la, lb, and lc traveling from the afocal optical system 40 increases. Increasing the divergence angle α [°] of the light la, lb, lc that proceeds from the afocal optical system 40 increases the incident angle of the light la, lb, lc to the first lens array 60, so that the light la, There is a possibility that lb and lc are not taken into the first lens array 60 as desired. Accordingly, the reduction rate of the optical path width of the light la, lb, lc in the afocal optical system 40 is different from the divergence angle α [°] of the light la, lb, lc traveling from the afocal optical system 40 in other words. Adjustment is performed in consideration of the incident angles of lb and lc to the first lens array 60 and the capture angle θ [°] of the first lens array 60 described later.

  Next, the scanning device 50 will be described. The scanning device 50 changes the traveling direction of light from the afocal optical system 40 over time. In the specific example shown in FIGS. 1 to 3, the scanning device 50 includes a reflecting member 51 having a reflecting surface 52, and a shaft member 53 that supports the reflecting member 51. As shown in FIGS. 2 and 3, the shaft member 53 is rotatable about a rotation axis R that is the axial direction thereof. As the shaft member 53 rotates, the reflecting member 51 supported by the shaft member 53 also rotates about the rotation axis R. However, the reflecting surface 52 is not orthogonal to the rotation axis R. In other words, the normal direction nd of the reflecting surface 52 is not parallel to the rotation axis R and is inclined with respect to the rotation axis R. Therefore, when the reflecting member 51 rotates about the rotation axis R, the reflecting surface 52 changes its direction. At this time, if the rotation of the reflection member 51 is constant, the reflection surface 52 periodically changes its direction around the virtual surface Vp orthogonal to the rotation axis R. Here, in the scanning device 50 shown in FIG. 2 and FIG. 3, the light that is incident on the scanning device 50 from a certain direction and is reflected by the reflecting surface 52 is accompanied by the rotation of the reflecting surface 52 around the rotation axis R. Then, it proceeds in a direction within an angle range of an angle β [°] centered on the normal direction of the virtual plane Vp. This angle β [°] corresponds to the scanning angle of the scanning device 50.

  Of course, the configuration of the scanning device 50 is not limited to this, and for example, a scanning device as shown in FIGS. 4 and 5 can also be employed. In the illustrated example, the scanning device 50a includes a reflecting member 51a having a reflecting surface 52a, and a reflecting member 51a that can be rotated about one rotation axis Ra. When the reflecting member 51a rotates about the rotation axis Ra, the reflecting surface 52a changes its direction. In the case of the scanning device 50a shown in FIG. 4 and FIG. 5, the reflection surface 52a is configured to periodically change the direction about a certain virtual surface Vpa parallel to the rotation axis Ra. Also in the example shown in FIGS. 4 and 5, the light that is incident on the scanning device 50a from a certain direction and is reflected by the reflecting surface 52a is accompanied by the rotation of the reflecting surface 52a around the rotation axis Ra. It proceeds in a direction within an angle range of an angle β [°] corresponding to the scanning angle of the scanning device 50a. Here, two scanning devices 50a shown in FIGS. 4 and 5 may be combined to perform biaxial scanning.

  The scanning angle β [°] of the scanning device 50 is the first lens array 60 of the light la, lb, lc together with the divergence angle α [°] of the light la, lb, lc that travels from the afocal optical system 40 described above. Affects the angle of incidence. Therefore, the scanning angle β [°] of the scanning device 50 takes into consideration the incident angle of the light la, lb, lc to the first lens array 60 and the capture angle θ [°] of the first lens array 60 described later. Adjusted.

  Next, the optical path adjustment optical system 55 will be described. The optical path adjustment optical system 55 includes a first lens array 60, a second lens array 70, and a deflection element 80. First, the first lens array 60 and the second lens array 70 will be described.

  The first lens array 60 is incident such that the light from the scanning device 50 scans, and includes a plurality of first unit lenses 61. More specifically, the first lens array 60 is formed by spreading first unit lenses 61 made of convex lenses. The plurality of first unit lenses 61 are arranged so that their optical axes are parallel to each other. The plurality of first unit lenses 61 are arranged on a virtual plane orthogonal to the optical axis.

  The second lens array 70 is disposed to face the first lens array 60, and includes a plurality of second unit lenses 71 provided corresponding to the first unit lenses 61 of the first lens array 60. Yes. More specifically, the second lens array 70 is configured in the same manner as the first lens array 60, and is formed by spreading second unit lenses 71 made of convex lenses.

  That is, two lens arrays having the same configuration are used as the first lens array 60 and the second lens array 70. The first lens array 60 and the second lens array 70 are arranged such that the optical axes of the unit lenses 61 and 71 included in the lens arrays 60 and 70 are parallel to each other. Further, one second unit lens 71 included in the second lens array 70 is disposed so as to face any one of the first unit lenses 61 included in the first lens array 60. More specifically, in the projection along the optical axis of the unit lenses 61 and 71, the outer contours of one first unit lens 61 and one unit lens 71 corresponding to the first unit lens 61 overlap. Thus, the first lens array 60 and the second lens array 70 are arranged. In particular, in the present embodiment, the principal point 72 of each second unit lens 71 is located on the rear focal point of the first unit lens 61 corresponding to the second unit lens 71. The “principal point” is the optical center of the lens and is the center point that determines the focal length.

  Next, the deflection element 80 will be described. The deflecting element 80 is disposed so as to face the second lens array 70 and changes the traveling direction of the light la, lb, lc from the second lens array 70. The deflection element 80 is composed of a lens that functions as a condenser lens or a field lens. The optical axis of the first unit lens 61 of the first lens array 60, the optical axis of the second unit lens 71 of the second lens array 70, and the optical axis of the lens forming the deflection element 80 are arranged in parallel. Has been.

  Due to the above-described configuration of the first lens array 60, the second lens array 70, and the deflection element 80, the light incident on a certain region of the first lens array 60 and the certain region of the first lens array 60 are different. The light that has entered the other region is adjusted in the optical path by the first lens array 60, the second lens array 70, and the deflecting element 80, respectively, and proceeds to the region that overlaps at least partially. In particular, the light incident on the entire area of each first unit lens 61 of the first lens array 60 is changed in optical path by the second unit lens 71 and the deflection element 80 corresponding to the first unit lens 61, so that the illuminated area Incident light enters the entire area of LZ. That is, the light incident on the entire area of each first unit lens 61 illuminates the entire area of the illuminated area LZ by adjusting the optical path.

  By the way, in the illuminating device 10 having such a configuration, the optical path width W1 of the light la, lb, lc from the light supply unit 30 is reduced by the afocal optical system 40, thereby reducing the size of the illuminating device 10. It is possible. However, on the other hand, as described above, the ratio of the optical path width W1 to the optical path width W2 increases as the reduction ratio of the optical path width of the light la, lb, lc in the afocal optical system 40 increases according to Etendue's conservation law. The larger the value is, the larger the divergence angle α [°] of the light la, lb, lc that proceeds from the afocal optical system 40 is.

  Further, since the scanning device 50 changes the optical paths of the light beams la, lb, and lc over time, the optical axes lax, lbx, and lcx of the light beams la, lb, and lc incident on the first lens array 60 are changed to the first lens. The first unit lens 61 of the array 60 has an angle with respect to the optical axis. This means that the incident angle range of the light la, lb, lc diverging at the divergence angle α [°] to the first unit lens 61 can be set to an incident angle range α + β [°] larger than α [°]. Means that.

  Here, as shown in FIG. 1, the first unit lens 61 has a capture angle θ [°]. The incident angle θ [°] of the first unit lens 61 is adjusted by the optical path adjustment by refraction at the first unit lens 61 in the direction parallel to the optical axis of the first unit lens 61. The size of the incident angle range. Therefore, the capture angle θ [°] of the first unit lens 61 is obtained when the parallel light beam incident along the optical axis of the first unit lens 61 is converted into a convergent light beam directed toward the focal point of the first unit lens 61. It can also be said to be the size of the optical path angle range of the convergent light beam. Further, in the example shown in FIG. 1, one main unit 72 from one principal point 72 of the second unit lens 71 corresponding to the first unit lens 61 in the cross section parallel to the optical axis of the first unit lens 61. The magnitude of the angle formed between the two straight line segments LS extending at both ends of the unit lens 61 coincides with the capture angle θ [°] of the first unit lens 61. In this case, when the incident angle range of the light incident on the first unit lens 61 exceeds the capture angle θ [°] of the first unit lens 61, the light corresponds to the incident first unit lens 61. There is a possibility that it will not be taken into the 2-unit lens and cannot be used effectively. That is, the utilization efficiency of the light la, lb, lc in the lighting device 10 is deteriorated. In addition, the light that has not been captured by the second unit lens becomes stray light or the like, which can adversely affect the illumination of the illuminated area LZ.

Considering the above, in the illumination device 10 according to the present embodiment, as shown in FIG. 1, the size of the incident angle range of the light la, lb, lc from the scanning device 50 is the first unit lens. The angle is 61 or less. That is, in the illuminating device 10 according to the present embodiment, the capturing angle θ [°] of the first unit lens 61, the divergence angle α [°] of the light traveling from the afocal optical system 40, and the scanning device 50 The scanning angle β [°] satisfies the following relationship.
α + β ≦ θ

  Next, the spatial light modulator 20 will be described. The spatial light modulator 20 is disposed so as to overlap the illuminated area LZ. The spatial light modulator 20 is illuminated with light from the illumination device 10 to form a modulated image. Lights la, lb, and lc from the illumination device 10 illuminate only the entire illuminated area LZ. Therefore, it is preferable that the incident surface of the spatial light modulator 20 has the same shape and size as the illuminated region LZ irradiated with the light la, lb, lc by the illumination device 10. This is because the light la, lb, lc from the illumination device 10 can be used with high utilization efficiency for the formation of a modulated image.

  The spatial light modulator 20 is not particularly limited, and various known spatial light modulators can be used. For example, a spatial light modulator that forms a modulated image without using polarized light, such as a digital mirror device (DMD), a transmissive liquid crystal microdisplay that forms a modulated image using polarized light, or a reflective LCoS (Liquid) Crystal On Silicon (registered trademark) can be used as the spatial light modulator 20.

  As in the example shown in FIG. 1, when the spatial light modulator 20 is a transmissive liquid crystal microdisplay, the spatial light modulator 20 illuminated in a planar shape by the illumination device 10 emits light for each pixel. By selecting and transmitting, a modulated image is formed on the screen of the display constituting the spatial light modulator 20. The modulated image thus obtained is finally projected on the screen 2 at the same magnification or scaled by the projection optical system 25. Thereby, the observer can observe the image projected on the screen 2. The screen 2 may be configured as a transmissive screen or a reflective screen.

  Next, the operation of the illumination device 10, the projection device 3, and the projection display device 1 having the above configuration will be described.

  First, as shown in FIG. 1, light oscillated by a laser light source (not shown) is guided by an optical fiber 32 of the light supply unit 30 and is emitted from the optical fiber 32. Lights 1 a, lb and lc emitted from the optical fiber 32 diverge and travel toward the collimating lens 33. At this time, the optical axes lax, lbx, lcx of the lights 1a, lb, lc emitted from the optical fiber 32 are substantially parallel to each other. Lights la, lb, and lc incident on the collimating lens 33 are collimated by the collimating lens 33 and are emitted from the collimating lens 33 as light having high parallelism.

  Lights la, lb, and lc emitted from the collimating lens 33 first enter the afocal optical system 40 and enter the first lens 41. At this time, the entire optical path width of the lights la, lb, and lc is the optical path width W1. Lights la, lb, and lc incident on the first lens 41 with the optical path width W1 are condensed and reduced toward the second lens 42 while reducing the entire optical path width. Lights la, lb, and lc incident on the second lens 42 are adjusted in their traveling directions so that their optical axes lag, lbx, and lcx are parallel to each other, and are emitted from the second lens 42. At this time, the entire optical path width of the lights la, lb, and lc is the optical path width W2. In this way, the optical path width of the light la, lb, lc incident on the afocal optical system 40 is reduced from the optical path width W1 to the optical path width W2. Here, according to Etendue's conservation law, the light la, lb, lc emitted from the second lens 42 is a reduction ratio of the optical path width of the light la, lb, lc in the afocal optical system 40, that is, the optical path width W1 and the optical path width. It has a divergence angle α [°] corresponding to the ratio to W2. Lights la, lb, and lc emitted from the second lens 42 at a divergence angle α [°] are directed to the scanning device 50.

  The traveling directions of the light beams la, lb, and lc incident on the scanning device 50 are changed by reflection on the reflection surface 52 and are directed to the optical path adjustment optical system 55. The direction of the reflecting surface 52 periodically varies as the shaft member 53 rotates at a constant speed. As a result, the traveling directions of the light beams la, lb, and lc emitted from the scanning device 50 also have an angle β [ Within the angle range of °]. That is, the light la, lb, lc is scanned by the scanning device 50 at the scanning angle β [°].

  Lights la, lb, and lc from the scanning device 50 enter the first lens array 60 of the optical path adjustment optical system 55. The light la, lb, lc from the scanning device 50 is changed in its traveling direction over time, so that the first lens array 60 is incident on the first lens array 60 while periodically changing the incident position and the incident angle. Incident light is scanned so as to scan the lens array 60. At this time, the incident angle range of the light la, lb, lc incident on the first unit lens 61 of the first lens array 60 is such that the light la, lb, lc has a divergence angle α [°] In addition, since the light beams la, lb, and lc are scanned at the scanning angle β [°], the incident angle range is α + β [°]. Lights la, lb, and lc emitted from the first unit lens 61 travel to the second lens array 70.

  Here, the taking-in angle of the first unit lens 61 is an angle θ [°]. Therefore, light incident on the first unit lens 61 from a direction equal to or smaller than the capturing angle θ [°] is directed to the second unit lens 71 corresponding to the incident first unit lens 61, but the capturing angle θ [°] is set. There is a possibility that the light incident from above the direction is not directed to the second unit lens 71 corresponding to the incident first unit lens 61 and cannot be used effectively. As a result, the utilization efficiency of the light la, lb, lc in the illumination device 10 is deteriorated. Further, the light that could not be captured becomes stray light or the like, which can adversely affect the illumination of the exposed area.

  However, in the illuminating device 10 according to the present embodiment, the capturing angle θ [°] of the first unit lens 61, the divergence angle α [°] of the light traveling from the afocal optical system 40, and the scanning device 50 The reduction ratio of the optical path width of light in the afocal optical system 40 and the scanning angle β [°] of the scanning device 50 are adjusted so that the scanning angle β [°] satisfies the relationship α + β ≦ θ. Thereby, the light la, lb, lc emitted from the first unit lens 61 travels to the second unit lens 71 corresponding to the first unit lens 61.

  In the light beams la, lb, and lc from the first unit lens 61, the principal point 72 of each second unit lens 71 is positioned on the rear focal point of the first unit lens 61 corresponding to the second unit lens 71. Thus, the light enters the second unit lens 71 while converging toward the principal point 72 of the corresponding second unit lens 71. Lights la, lb, and lc incident on the second unit lens 71 are diffused or expanded by the second unit lens 71 and enter the deflection element 80. Note that the incident positions of the light beams la, lb, and lc incident on the first and second lens arrays 60 and 70 change over time, so that the deflecting element 80 passes through the first and second lens arrays 60 and 70. The incident position on the deflection element 80 that enters the beam also periodically changes. The lights la, lb, and lc incident on each area of the deflection element 80 are directed to the illuminated area LZ as illumination light that illuminates the entire illumination area LZ by the optical path adjustment function of the deflection element 80.

  That is, the light incident on each area of the optical path adjustment optical system 55 is superimposed on the illuminated area LZ by the optical path adjustment function of the optical path adjustment optical system 55. The light incident on each area of the optical path adjustment optical system 55 from the scanning device 50 is diffused or expanded by the optical path adjustment optical system 55, and enters the entire illuminated area LZ. Thus, the illuminating device 10 can illuminate the illuminated area LZ with light. And the incident direction of the light which injects into each position of the to-be-illuminated area | region LZ changes continuously. That is, the illuminated area LZ is illuminated with light whose incident direction changes over time.

  As shown in FIG. 1, in the projection device 3, the spatial light modulator 20 is disposed at a position overlapping the illuminated area LZ of the illumination device 10. For this reason, the spatial light modulator 20 is illuminated in a planar shape by the illumination device 10 and forms an image by selecting and transmitting light for each pixel. This image is projected onto the screen 2 by the projection optical system 25. The light projected on the screen 2 is diffused and recognized as an image by the observer. The illuminated area LZ is illuminated from various directions corresponding to the respective areas on the first lens array 60, and accordingly, image light is directed to each position of the screen 2 from a direction that changes over time. Incident. For this reason, speckles generated by diffusing image light as coherent light on the screen 2 are superimposed at high speed, and as a result, speckles can be made inconspicuous.

According to the embodiment of the present disclosure as described above, the illumination device 10 includes the unit light emitting unit including the optical fiber 32 and the lens 33 that suppresses the divergence angle of the light emitted from the optical fiber 32, for example, a collimator lens. 35, afocal optical system 40 for reducing the optical path width of light la, lb, lc from light supply unit 30, and advancing of light la, lb, lc from afocal optical system 40 The scanning device 50 that changes the direction over time, the first lens array 60 that is incident so that the light la, lb, and lc from the scanning device 50 scans, and the first lens array 60 are disposed. A second lens array 70 and a deflecting element 80 that changes the traveling direction of the light beams la, lb, and lc from the second lens array 70 disposed to face the second lens array 70, and The light incident on a certain area of the array 60 and the light incident on another area different from the certain area of the first lens array 60 are the first lens array 60, the second lens array 70, and the deflecting element, respectively. The optical path is adjusted at 80 to proceed to an area at least partially overlapping, and the first lens array 60 includes a plurality of first unit lenses 61, and the second lens array 70 includes each first lens array 60. A plurality of second unit lenses 71 provided corresponding to the unit lens 61, a taking-in angle θ [°] of the first unit lens 61, a divergence angle α [°] of the light that has advanced from the afocal optical system 40, And the scanning angle β [°] in the scanning device 50 satisfies the following relationship.
α + β ≦ θ

  In such an illuminating device 10, the light la, lb, lc from the plurality of optical fibers 32 is used to brightly illuminate the illuminated area, while the light la, lb, lc from the plurality of optical fibers 32 is used. The illumination apparatus 10 is downsized by reducing the optical path width of the illumination apparatus 10 by the afocal optical system 40. In addition, speckles are made inconspicuous by changing the traveling directions of the light beams la, lb, and lc from the plurality of optical fibers 32 over time using the scanning device 50. On the other hand, the first lens array 60 has a divergence angle α [°] corresponding to the reduction ratio of the optical path width in the afocal optical system 40 according to Etendue's law, and a scanning angle β [ The light la, lb, lc scanned at [°] is incident. However, in the illuminating device 10, the divergence angle α [°] of the light traveling from the afocal optical system 40 and the scanning angle β [°] of the scanning device 50 are equal to or smaller than the capturing angle θ [°] of the first unit lens 61. That is, it is adjusted so that α + β ≦ θ. As a result, the possibility that the light la, lb, lc incident on the first unit lens 61 cannot be effectively used without being captured by the corresponding second unit lens 71 is reduced. That is, according to the embodiment of the present disclosure, the light use efficiency can be improved in the illumination device 10 that uses light from the plurality of optical fibers 32.

  Further, according to the embodiment of the present disclosure, the principal point 72 of each second unit lens 71 is located on the rear focal point of the first unit lens 61 corresponding to the second unit lens 71. Thereby, the optical path adjustment in the first lens array 60, the second lens array 70, and the deflection element 80 can be performed with higher accuracy, and speckles can be effectively made inconspicuous.

  Further, the projection device 3 according to the embodiment of the present disclosure includes the above-described illumination device 10 according to the embodiment of the present disclosure, and the spatial light modulator 20 that is illuminated by the light la, lb, and lc from the illumination device 10. . In the illumination device 10 of the projection device 3 described above, the light la, lb, lc from the plurality of optical fibers 32 is used to illuminate the illuminated area brightly, while the light la from the plurality of optical fibers 32 is used. , Lb, and lc are reduced by the afocal optical system 40 to reduce the size of the illumination device 10. In addition, speckles are made inconspicuous by changing the traveling directions of the light beams la, lb, and lc from the plurality of optical fibers 32 over time using the scanning device 50. On the other hand, the first lens array 60 has a divergence angle α [°] corresponding to the reduction ratio of the optical path width in the afocal optical system 40 according to Etendue's law, and a scanning angle β [ The light la, lb, lc scanned at [°] is incident. However, in the illuminating device 10, the divergence angle α [°] of the light traveling from the afocal optical system 40 and the scanning angle β [°] of the scanning device 50 are equal to or smaller than the capturing angle θ [°] of the first unit lens 61. That is, it is adjusted so that α + β ≦ θ. As a result, the possibility that the light la, lb, lc incident on the first unit lens 61 cannot be effectively used without being captured by the corresponding second unit lens 71 is reduced. That is, according to the embodiment of the present disclosure, in the projection device 3 using the illumination device 10 that uses light from the plurality of optical fibers 32, the illumination light with reduced speckle noise while improving the light utilization efficiency. Can be obtained.

  The present disclosure is not limited to the above-described embodiments and modifications, and may include various aspects to which various modifications that can be conceived by those skilled in the art are added, and the effects achieved by the present disclosure are also described above. It is not limited to the matter of. Therefore, various additions, modifications, and partial deletions can be made to each element described in the claims and the specification without departing from the technical idea and spirit of the present disclosure.

DESCRIPTION OF SYMBOLS 1 Projection type display apparatus 2 Screen 3 Projection apparatus 10 Illumination apparatus 20 Spatial light modulator 25 Projection optical system 30 Light supply part 32 Optical fiber 33 Collimate lens 35 Unit light emission part 40 Afocal optical system 50 Scanning apparatus 60 1st lens array 61 First unit lens 70 Second lens array 71 Second unit lens 80 Deflection element

Claims (4)

A light supply unit including a plurality of unit light emitting units having an optical fiber and a lens for suppressing a divergence angle of light emitted from the optical fiber;
An afocal optical system that reduces the optical path width of the light from the light supply unit;
A scanning device that changes the traveling direction of light from the afocal optical system over time;
A first lens array incident so that light from the scanning device scans;
A second lens array disposed opposite the first lens array;
A deflecting element that changes a traveling direction of light from the second lens array disposed to face the second lens array;
The light incident on a certain area of the first lens array and the light incident on another area different from the certain area of the first lens array are respectively the first lens array and the second lens. The optical path is adjusted by the array and the deflection element, and at least partially overlaps the area,
The first lens array includes a plurality of first unit lenses,
The second lens array includes a plurality of second unit lenses provided corresponding to the first unit lenses of the first lens array,
The capturing angle θ [°] of the first unit lens, the divergence angle α [°] of the light that has advanced from the afocal optical system, and the scanning angle β [°] of the scanning device satisfy the following relationship: , Lighting equipment.
α + β ≦ θ   2. The illumination device according to claim 1, wherein a principal point of each second unit lens is located on a rear focal point of the first unit lens corresponding to the second unit lens.   The lighting device according to claim 1, wherein the lens that suppresses the divergence angle is a collimating lens. The lighting device according to any one of claims 1 to 3,
And a spatial light modulator illuminated by light from the illumination device.

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