JP6950339B2 - Lighting equipment and projectors - Google Patents

Description

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

In recent years, in a lighting device for a projector, there is a technique for making the illuminance distribution of an excitation light spot uniform by arranging a diffuser plate in a condensing optical system arranged between an excitation light source and a phosphor (for example). , See Patent Document 1 below).
Further, there is also a technique for making the illuminance distribution of the excitation light spot uniform by using two multi-lenses in the projector (see, for example, Patent Document 2 below).

Japanese Unexamined Patent Publication No. 2011-197597 Japanese Unexamined Patent Publication No. 2014-138148

However, in the prior art described in Patent Document 1, since the spot of the excitation light is large, the fluorescence generated by the phosphor is not efficiently taken into the optical system in the subsequent stage, and there is a problem that the light utilization efficiency is lowered. be. Further, according to the prior art described in Patent Document 2, the uniformity of the illuminance distribution can be improved as compared with the case of using the diffuser plate, but the number of parts increases due to the use of two multi-lenses. There is a problem such as.

The present invention has been made in view of such circumstances, and one of the objects of the present invention is to provide a lighting device capable of making an illuminance distribution uniform in an illuminated region while having a small number of parts. Another object of the present invention is to provide a projector equipped with the lighting device.

According to the first aspect of the present invention, a light source device including a first light emitting element that emits a first light beam bundle, and an optical molding optical system including a first lens surface on which the first light beam bundle is incident. The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables, and in the equation (1), h is a positive integer. Then, a lighting device is provided in which the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h.

The lighting device according to the first aspect can make the spots of the first light beam bundle formed on the illuminated area rectangular, and can make the illuminance distribution of the spots uniform. Therefore, the number of parts can be reduced as compared with the conventional method using two multi-lens arrays. Further, by using the above equation (1), the curvatures in the x-direction and the y-direction can be designed independently, which facilitates the design of the lens.

In the first aspect, wherein the formula (1) comprises at least one of the first-order term and first-order term of y of x, p, when the q is a positive integer, the x ^p y ^q It is preferable to include at least one term.
According to this configuration, the traveling direction of the first ray bundle can be deflected. Further, it is possible to correct the distortion generated when the traveling direction of the first ray bundle is deflected.

In the first aspect, the photoforming optical system further includes a refracting surface that deflects the traveling direction of the first light flux, and the equation (1) is x when p and q are positive integers. ^It is preferable to include at least one term of py ^q.
According to this configuration, it is possible to correct the distortion generated when the traveling direction of the first ray bundle is deflected by the refracting surface.

In the first aspect, the polynomial included in the equation (1) preferably consists of even-numbered terms of x and even-numbered terms of y.
According to this configuration, the shape design of the first lens becomes easy.

In the first aspect, the refracting surface is preferably flat.
According to this configuration, the traveling direction of the first ray bundle can be deflected with a simple configuration.

In the first aspect, the photoforming optical system further includes a reflecting surface that reflects the first light flux and deflects the traveling direction of the first light bundle, and the formula (1) is based on p. when the q is a positive integer, preferably includes at least one term of x ^p y ^q.
According to this configuration, it is possible to correct the distortion generated when the traveling direction of the first light beam bundle is deflected by the reflecting surface.

In the first aspect, the polynomial included in the equation (1) preferably consists of even-numbered terms of x and even-numbered terms of y.
According to this configuration, the shape design of the first lens becomes easy.

In the first aspect, the photomolding optical system has a light incident surface and a light emitting surface, and one of the light incident surface and the light emitting surface is composed of the first lens surface. The main light beam of the light bundle is preferably incident in the plane normal direction on the other side of the light incident surface and the light emitting surface.
According to this configuration, it is possible to prevent the main ray of the first ray bundle from being refracted when it is incident on the light incident surface or when it is emitted from the light emitting surface. As a result, it is possible to reduce the variation in the traveling direction due to the refraction of the main ray of the first ray bundle.

In the first aspect, it is preferable to further include a condenser lens provided on the optical path of the first light beam bundle between the first light emitting element and the first lens.
According to this configuration, the divergence angle of the first light beam bundle can be adjusted, so that the design condition of the first lens is relaxed.

In the first aspect, it is preferable to further include a wavelength conversion element to which the first light flux transmitted through the photoforming optical system is incident.
According to this configuration, fluorescent light can be generated with high efficiency by the first light beam bundle having high uniformity of the illuminance distribution.

In the first aspect, the light source device further includes a second light emitting element that emits a second light beam bundle, and the photoforming optical system further includes a second lens into which the second light beam bundle is incident. The second lens has a second free curved surface represented by the above equation (1), and the coefficient C _j ^{of the term x 2h} is the coefficient of the term y ^{2h with respect to the second free curved surface.} Unlike _Cj , the photoforming optical system is preferably configured such that the first light beam bundle and the second light beam bundle illuminate the illuminated area in an overlapping manner.
According to this configuration, since the first light beam bundle and the second light ray bundle are superimposed, the uniformity of the illuminance distribution in the illuminated region can be further improved.

In the first aspect, it is preferable to further include a light source control device that controls the output of the first light emitting element independently of the output of the second light emitting element.
According to this configuration, the illuminance of the entire illuminated area can be adjusted by controlling the output of the first light emitting element.

In the first aspect, it is preferable to further include a condenser lens provided on the optical path of the first light beam bundle between the first light emitting element and the first lens surface.
According to this configuration, the divergence angle of the first light beam bundle can be adjusted, so that the design condition of the first lens is relaxed.

In the first aspect, it is preferable that a wavelength conversion element is further provided, and a predetermined region of the wavelength conversion element corresponds to the illuminated region.
According to this configuration, fluorescent light can be generated with high efficiency by light having a highly uniform illuminance distribution.

In the first aspect, the light source device further includes a second light emitting element that emits a second light beam bundle, and the photoforming optical system further includes a second lens into which the second light beam bundle is incident. The second lens has a second free curved surface represented by the above equation (1), and the coefficient C _j ^{of the term x 2h} is the coefficient of the term y ^{2h with respect to the second free curved surface.} Unlike _Cj , the photoforming optical system is preferably configured so that the first light flux and the second light bundle are incident on different regions of the illuminated region.
According to this configuration, it is possible to illuminate an illuminated area of an arbitrary size with a uniform illuminance distribution.

In the first aspect, it is preferable to further include a light source control device that controls the output of the first light emitting element independently of the output of the second light emitting element.
According to this configuration, the uniformity of the illuminance distribution in the illuminated area can be improved. Further, the illuminance distribution in the illuminated area can be set to a desired distribution.

In the first aspect, it is preferable that a wavelength conversion element is further provided, and a predetermined region of the wavelength conversion element corresponds to the illuminated region.
According to this configuration, fluorescent light can be generated with high efficiency by light having a highly uniform illuminance distribution.

According to the second aspect of the present invention, the illumination device of the first aspect, the light modulation device that modulates the illumination light from the illumination device according to the image information to generate the image light, and the image light are projected. Provided is a projector comprising a projection optical system for the purpose of light generation, and an image forming region of the optical modulator corresponding to the illuminated region.

The projector according to the second aspect can illuminate the image forming region of the light modulation device with a uniform illuminance distribution. Therefore, it is possible to display an image in which uneven brightness is reduced.

According to the third aspect of the present invention, the illumination device of the first aspect, the light modulation device that modulates the illumination light from the light source device according to the image information to generate the image light, and the image light are projected. The light source device further includes a third light emitting element that emits a third light bundle, and the photoforming optical system has a third light flux incident on the third light bundle. Further comprising a light source, the third lens has a third free curved surface represented by the above formula (1), and the coefficient C _j ^{of the term x 2h} is y ^2h with respect to the third free curved surface. is different from the coefficient C _j sections, wherein the light shaping optical system, the third is constructed as light beam illuminates the entire illuminated area, the light source control device, the third light emitting The output of the element is controlled so as to be controlled independently of at least one of the output of the first light emitting element and the output of the second light emitting element, and the image forming region of the light modulator is the said. A light source corresponding to an illuminated area is provided.

The projector according to the third aspect controls the output of the third light emitting element independently of at least one of the output of the first light emitting element and the output of the second light emitting element, thereby forming an image of the light modulator. The formation region can be set to a desired illuminance distribution.

According to the fourth aspect of the present invention, the illumination device of the first aspect, the optical modulation device that modulates the illumination light from the wavelength conversion element according to the image information to generate the image light, and the image light. A projector equipped with a projection optical system for projecting is provided.

The projector according to the fourth aspect can display a bright image.

The schematic diagram which shows the optical system of the projector which concerns on 1st Embodiment. The figure which shows the schematic structure of the lighting apparatus. The figure which shows the main part structure of the optical molding optical system. The figure which shows the schematic structure of the 1st lighting apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the optical system of the projector which concerns on 3rd Embodiment. The schematic diagram which shows the 1st lighting apparatus which concerns on 4th Embodiment. The schematic diagram which shows the 1st lighting apparatus which concerns on 5th Embodiment. The schematic diagram which shows the 1st lighting apparatus which concerns on 6th Embodiment. The figure which conceptually showed the illumination system of the illuminated area which concerns on the 1st modification. The figure which conceptually showed the illumination system of the illuminated area which concerns on the 2nd modification. The figure which conceptually showed the illumination system of the illuminated area which concerns on the 3rd modification. The figure which shows the illuminance distribution when the spherical lens is used in Example 1. FIG. The figure which shows the illuminance distribution when the free-form surface lens of Example 1 is used. The figure which shows the illuminance distribution when the spherical lens is used in Example 2. FIG. The figure which shows the illuminance distribution when the free-form surface lens of Example 2 is used. The figure which shows the illuminance distribution when the spherical lens is used in Example 5. The figure which shows the illuminance distribution when the free-form surface lens of Example 5 is used. The figure which shows the illuminance distribution when the spherical lens is used in Example 6. The figure which shows the illuminance distribution when the free-form surface lens of Example 6 is used.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, the featured parts may be enlarged for convenience, and the dimensional ratio of each component may not be the same as the actual one. No.

(First Embodiment)
FIG. 1 is a schematic view showing an optical system of a projector according to the present embodiment.
As shown in FIG. 1, the projector 1 includes a lighting device 100, a color separation light guide optical system 200, a liquid crystal light modulation device 400R, a liquid crystal light modulation device 400G, a liquid crystal light modulation device 400B, and a cross dichroic prism 500. And a projection optical system 600.

The lighting device 100 includes a first lighting device 101 and a second lighting device 102. The first illumination device 101 emits illumination light W1 (fluorescent light YL) including red light and green light toward the color-separated light guide optical system 200. The second illuminating device 102 emits blue light B toward the color-separated light guide optical system 200.

The color-separated light guide optical system 200 includes a dichroic mirror 210, a reflection mirror 220, a reflection mirror 230, and a reflection mirror 250. The color separation light guide optical system 200 separates the illumination light W1 emitted from the first illumination device 101 into red light R and green light G, and guides the illumination light W1 to the corresponding liquid crystal light modulator 400R and liquid crystal light modulator 400G, respectively. It glows. Further, the color separation light guide optical system 200 guides the blue light B emitted from the second lighting device 102 to the liquid crystal light modulation device 400B. The field lens 300R, the field lens 300G, and the field lens 300B are arranged between the color separation light guide optical system 200 and the liquid crystal light modulator 400R, the liquid crystal light modulator 400G, and the liquid crystal light modulator 400B.

The dichroic mirror 210 is a dichroic mirror that allows a red light component to pass through and reflects a green light component. The reflection mirror 220 is a mirror that reflects a green light component. The reflection mirror 230 is a mirror that reflects a red light component. The reflection mirror 250 is a reflection mirror that reflects a blue light component.

The red light R that has passed through the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the field lens 300R, and is incident on the image forming region of the liquid crystal light modulator 400R for red light. The green light G reflected by the dichroic mirror 210 is further reflected by the reflection mirror 220, passes through the field lens 300G, and is incident on the image forming region of the liquid crystal light modulator 400G for green light. The blue light B reflected by the reflection mirror 250 enters the image forming region of the liquid crystal light modulator 400B for blue light through the field lens 300B.

The liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B modulate the incident color light according to the image information to form the image light corresponding to each color.
Although not shown, incident side polarizing plates are arranged on the light incident side of the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B, respectively. A polarizing plate on the emission side is arranged on the light emission side of the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B, respectively.

The cross dichroic prism 500 forms a color image by synthesizing each image light emitted from the liquid crystal light modulation device 400R, the liquid crystal light modulation device 400G, and the liquid crystal light modulation device 400B. The cross-dichroic prism 500 has a substantially square shape in a plan view in which four right-angled prisms are bonded together, and a dielectric multilayer film is formed at a substantially X-shaped interface in which the right-angled prisms are bonded to each other.

The color image ejected from the cross dichroic prism 500 is magnified and projected onto the screen SCR by the projection optical system 600.

Subsequently, the configuration of the lighting device 100 will be described.
FIG. 2 is a diagram showing a schematic configuration of the lighting device 100. As shown in FIG. 2, the first lighting device 101 includes a first light source device 10, an optical molding optical system 20, a rotating fluorescent plate 30, a pickup optical system 60, a first lens array 120, and a second lens array. It includes 130, a polarization conversion element 140, a superimposing lens 150, and a control device 160.

The first light source device 10 has a plurality of semiconductor lasers 11 that emit blue laser light (for example, light having a peak emission intensity of about 445 nm) LB as excitation light. As the semiconductor laser 11, a laser that emits a blue laser light having a wavelength other than 445 nm, for example, 460 nm may be used.

Hereinafter, the drawings may be described using the XYZ coordinate system as necessary. The X direction is a direction along the illumination optical axis 100ax, the Z direction is a direction along the vertical direction, and the Y direction is a direction orthogonal to the X direction and the Z direction, respectively.
In this embodiment, the plurality of semiconductor lasers 11 are arranged two-dimensionally. Specifically, the plurality of semiconductor lasers 11 have a matrix shape (for example, 5 rows in the Y direction and 5 columns in the Z direction in FIG. 2) in a plane perpendicular to the illumination optical axis 100ax (in a plane parallel to the YZ plane). Are arranged in. Note that FIG. 2 shows only one row of semiconductor lasers 11 out of the plurality of semiconductor lasers 11. The first light source device 10 emits excitation light KS composed of a plurality of laser light LBs.

The plurality of semiconductor lasers 11 are electrically connected to the control device 160. The control device 160 can independently control the output of each laser light LB by, for example, controlling the current value supplied to each of the plurality of semiconductor lasers 11. The control device 160 corresponds to the "light source control device" in the claims.

The excitation light KS emitted from the first light source device 10 is incident on the rotating fluorescent plate 30 via the photoforming optical system 20. The configuration of the optical molding optical system 20 will be described later.

The rotating fluorescent plate 30 includes a motor 50, a base material 40, a dichroic layer 41, and a phosphor layer 42. The rotating fluorescent plate 30 emits fluorescent light YL toward the side opposite to the side on which the excitation light KS composed of blue light is incident. That is, the rotating fluorescent plate 30 is a transmissive rotating fluorescent plate.

The base material 40 is made of a translucent material such as glass, quartz, and sapphire. The base material 40 is made rotatable around a rotation axis by a motor 50. The base material 40 is a plate having a circular planar shape.

The phosphor layer 42 is composed of an inorganic phosphor material having an annular planar shape. As the phosphor layer 42, for example, a phosphor layer in which fluorescent particles emitting yellow fluorescent light are dispersed in an inorganic binder such as alumina, a phosphor layer in which fluorescent particles are sintered without using a binder, and the like. Is used. The phosphor layer 42 is provided around the rotation axis on one side 40a side of the base material 40. In the present embodiment, the phosphor layer 42 corresponds to the "wavelength conversion element" in the claims.

In general, the stronger the intensity of the excitation light incident on the phosphor layer 42, the lower the efficiency with which the phosphor layer converts the excitation light into fluorescence. Therefore, if the illuminance distribution of the excitation light is made uniform, it is possible to prevent the strong excitation light from being locally irradiated, so that the fluorescent light YL can be generated with high efficiency.

By using the optical molding optical system 20, the first illumination device 101 of the present embodiment uses the excitation light KS (each laser beam) so as to make the illuminance distribution of a predetermined region (illuminated region) of the phosphor layer 42 uniform. LB) is incident on the phosphor layer 42.

Hereinafter, a specific configuration of the optical molding optical system 20 will be described.
FIG. 3 is a diagram showing the configuration of the optical molding optical system 20. In FIG. 3, for convenience of explanation, only the phosphor layer 42 illuminated by the excitation light KS among the rotating fluorescent plates 30 is shown. Further, in FIG. 3, only the semiconductor laser 11 in the third row among the plurality of semiconductor lasers 11 is shown. As shown in FIG. 3, the optical molding optical system 20 is provided on the light emitting side of the first light source device 10, and the light emitted from the first light source device 10 is incident on the optical molding optical system 20.

The plurality of semiconductor lasers 11 include a first semiconductor laser 11a, a second semiconductor laser 11b, and a third semiconductor laser 11c. Hereinafter, the laser light LB emitted from the first semiconductor laser 11a is the laser light LB1, the laser light LB emitted from the second semiconductor laser 11b is the laser light LB2, and the laser light emitted from the third semiconductor laser 11c. LB is referred to as laser light LB3.

The first light source device 10 corresponds to the "light source device" in the scope of the patent claim, the first semiconductor laser 11a corresponds to the "first light emitting element" in the scope of the patent claim, and the second semiconductor laser 11b corresponds to the patent. The third semiconductor laser 11c corresponds to the "second light emitting element" in the claimed range, and corresponds to the "third light emitting element" in the patented range.

Further, the laser light LB1 corresponds to the "first light bundle" in the claims, the laser light LB2 corresponds to the "second light bundle" in the claims, and the laser light LB3 corresponds to the claims. Corresponds to the "third ray bundle" of.

The optical molding optical system 20 has a plurality of lenses 21 arranged in an array. Each of the plurality of lenses 21 is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of lenses 21 are arranged in a matrix (for example, in FIG. 3, 5 rows in the Y direction and 5 columns in the Z direction). Note that FIG. 3 shows only the lens 21 corresponding to the semiconductor laser 11 in the third row.
In the following description, the optical path of the laser light LB emitted from each of the plurality of semiconductor lasers 11 forming the same row (third row), that is, the optical path of the laser light LB in the plane parallel to the XY plane will be described as an example. do.

In the present embodiment, the optical molding optical system 20 is configured such that the laser light LB emitted from each of the plurality of semiconductor lasers 11 superimposes the predetermined region of the phosphor layer 42. The fact that the laser light LBs are superimposed on each other means that the spots of the laser light LBs are substantially overlapped with each other.

In this embodiment, the spots SP of each laser beam LB are superimposed on each other in a predetermined region on the phosphor layer 42. The region where the spots SP of each laser beam LB are superimposed on each other corresponds to the illuminated region SA in the phosphor layer 42.

The plurality of lenses 21 include a first lens 21a, a second lens 21b, and a third lens 21c. The first lens 21a corresponds to the first semiconductor laser 11a, the second lens 21b corresponds to the second semiconductor laser 11b, and the third lens 21c corresponds to the third semiconductor laser 11c.

Therefore, the laser light LB1 emitted from the first semiconductor laser 11a is incident on the first lens 21a, and the laser light LB2 emitted from the second semiconductor laser 11b is incident on the second lens 21b, and the third The laser beam LB3 emitted from the semiconductor laser 11c of the above is incident on the third lens 21c.

In the present embodiment, each of the plurality of lenses 21 is composed of a free curved surface lens having a free curved surface. Each of the plurality of lenses 21 forms a spot SP formed on the illuminated region (fluorescent layer 42) by the corresponding laser light LB and homogenizes the illuminance distribution.

Hereinafter, the structure of the plurality of lenses 21 will be described by taking the first lens 21a as an example. The first lens 21a has a first free curved surface 22a defined by a polynomial with x and y as variables on at least one surface (for example, a light emitting surface). The first free curved surface 22a has a rotationally asymmetrical shape. Specifically, the first free curved surface 22a is represented by the following equation (1). Equation (1) uses a Cartesian coordinate system whose z-axis is a direction parallel to the main ray of the light ray incident on the first free-form surface 22a. The light emitting surface having the first free curved surface 22a corresponds to the "first lens surface" in the claims.

In the above formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 . Note that m ₁ and n ₁ are upper limits of m and n, respectively.

In the first free-form surface 22a of the first lens 21a, when h is a positive integer, the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h. That is, the polynomial includes _{a term of C j} x ^{2 h and} a term of C _ky ^{2 h} , and C _j ≠ C _k . Hereinafter, "the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h " may be referred to as the first condition.

Generally, the intensity of laser light has a Gaussian distribution. Therefore, an illuminance distribution with low uniformity is formed in the illuminated area where the laser beam is incident. On the other hand, according to the first free curved surface 22a that satisfies the first condition, the spot SP of the laser beam LB1 is rectangularized, and the illuminance distribution of the spot SP is converted into a so-called top hat distribution to make it uniform.

Further, the above equation (1) includes at least one of a first-order term of x and a first-order term of y. That is, at least one of the coefficient of x and the coefficient of y is not 0. Hereinafter, "including at least one of the first-order term of x and the first-order term of y" may be referred to as a second condition.

According to the first free curved surface 22a that satisfies the second condition, the laser beam LB1 can be deflected. Thereby, the spot SP of the laser beam LB1 can be adjusted to a desired position. Therefore, as shown in FIG. 3, the laser beam LB1 can be incident on the phosphor layer 42. Further, since the first free curved surface 22a satisfies the first condition, the illuminated region SA formed on the phosphor layer 42 is rectangular, and the illuminance distribution by the laser light LB1 is made uniform.

Further, in the first free-form surface 22a, the above equation (1) is, when p, the q positive ^integers, comprising at least one term of x p ^{y q.} That is, the coefficient of at least one of the terms that combine x and y is not 0. Hereinafter also referred to as a third condition that "at least one term of x ^p y ^q".

When the laser beam LB1 is deflected as described above, the spot SP may be distorted. On the other hand, the first free curved surface 22a corrects the distortion due to the deflection by satisfying the third condition. As a result, the distortion of the illuminated area SA is reduced.

As described above, the first lens 21a has a first free curved surface 22a that satisfies the first to third conditions. Therefore, the laser light LB1 can form a spot SP having a rectangular shape and a uniform illuminance distribution on the phosphor layer 42.

Similarly, the second lens 21b has a second free curved surface 22b on the light emitting surface. The second free-form surface 22b is defined by the polynomial of the above equation (1), and this polynomial satisfies the above-mentioned first and third conditions. The laser light LB2 emitted from the second lens 21b can form a spot SP having a rectangular shape and a uniform illuminance distribution on the phosphor layer 42, similarly to the laser light LB1. The second free curved surface 22b superimposes the laser light LB2 and the laser light LB1 on the phosphor layer 42. The light emitting surface having the second free curved surface 22b corresponds to the "second lens surface" in the claims.

Similarly, the third lens 21c has a third free curved surface 22c on the light emitting surface. The third free-form surface 22c is defined by the polynomial of the above equation (1), and this polynomial satisfies the above-mentioned first to third conditions. The laser light LB3 emitted from the third lens 21c forms a rectangular spot SP having a uniform illuminance distribution on the phosphor layer 42, similarly to the laser lights LB1 and B2. The light emitting surface having the third free curved surface 23a corresponds to the "third lens surface" in the claims.

The third free curved surface 22c superimposes the laser light LB3 on the laser light LB1 and the laser light LB2 on the phosphor layer 42.

The rest of the plurality of lenses 21 have a free curved surface defined by a polynomial that satisfies the first to third conditions, like the first lens 21a, the second lens 21b, and the third lens 21c described above. There is. The laser light LB emitted from each lens 21 has a rectangular and uniform illuminance distribution on the phosphor layer 42, and forms spots SP that overlap each other.
In the above description, the spots formed by the laser light LB in the plane parallel to the XY plane have been described as an example, but they are emitted from each of the plurality of semiconductor lasers 11 forming the same row (arranged in the Z direction). The same can be said for the laser light LB, that is, the spot formed by the laser light LB in the plane parallel to the XZ plane.
Therefore, the laser light LB emitted from each lens 21 arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax has a rectangular and uniform illuminance distribution on the phosphor layer 42, and the spots SP are superimposed on each other. To form.

As described above, according to the photoformed optical system 20 of the present embodiment, the illuminated region SA is formed on the phosphor layer 42 by superimposing the spot SPs of the laser beams LB on each other. Therefore, the illuminated region SA The illuminance distribution in is highly uniform. Even if the outputs of the plurality of semiconductor lasers 11 (the amount of light of the laser light LB) vary, the phosphor layer 42 can be uniformly illuminated.
Further, since the optical molding optical system 20 is configured by replacing the collimating lens array conventionally used for parallelizing each laser light LB with a plurality of lenses 21, two conventional multi-lenses are used. Therefore, the number of parts can be reduced as compared with the configuration in which the illuminance distribution is made uniform.

Therefore, according to the first illumination device 101 of the present embodiment, the illuminance distribution of the illuminated region SA formed on the phosphor layer 42 can be made uniform even though the number of parts is small. Therefore, the fluorescent light YL can be generated with high efficiency.

Further, since the rectangular spots SP are superimposed on the phosphor layer 42 to form the illuminated region SA, it is possible to prevent the emission region of the fluorescent light YL from becoming large. Therefore, the subsequent optical system (pickup optical system 60) can take in the fluorescent light YL emitted from the phosphor layer 42 with high efficiency, so that the fluorescent light YL can be used efficiently.

According to the first lighting device 101 of the present embodiment, the output of each laser beam LB can be independently controlled by the control device 160. In this way, the illuminance in the entire illuminated region SA formed on the phosphor layer 42 can be adjusted.

Returning to FIG. 2, the fluorescent light YL generated by the rotating fluorescent plate 30 is incident on the pickup optical system 60. The pickup optical system 60 is composed of, for example, two pickup lenses 60a and 60b. The pickup optical system 60 parallelizes the fluorescent light YL and guides it to the first lens array 120.

The first lens array 120 has a plurality of first small lenses 122 for dividing the fluorescent light YL into a plurality of partial luminous fluxes. The plurality of first small lenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130, together with the superposed lens 150 in the subsequent stage, forms an image of the first small lens 122 of the first lens array 120 in or near the image forming regions of the liquid crystal light modulator 400R and the liquid crystal light modulator 400G, respectively. Let me. The plurality of second small lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

The polarization conversion element 140 converts each partial luminous flux (fluorescent light YL) divided by the first lens array 120 into linearly polarized light having the same polarization direction.

The superimposing lens 150 collects each partial luminous flux emitted from the polarization conversion element 140 and superimposes them on each other in or near the image forming regions of the liquid crystal light modulation device 400R and the liquid crystal light modulation device 400G. The first lens array 120, the second lens array 130, and the superposed lens 150 constitute an integrator optical system that makes the in-plane light intensity distribution of the fluorescent light YL emitted from the rotating fluorescent plate 30 uniform.

On the other hand, the second illumination device 102 includes a second light source device 710, a condensing optical system 720, a scattering plate 730, a pickup optical system 731, a lens integrator optical system 740, and a superimposing lens 760.

Like the first light source device 10, the second light source device 710 has a semiconductor laser 11 that emits a blue laser beam LB. The number of semiconductor lasers 11 may be one or a plurality. The second light source device 710 is adapted to emit blue light B composed of laser light. The semiconductor laser 11 of the second light source device 710 is also electrically connected to the control device 160. The control device 160 can control the output of the blue light B by controlling the current value supplied to the semiconductor laser 11.

As shown in FIG. 2, the condensing optical system 720 includes a first lens 722 and a second lens 724. As a whole, the condensing optical system 720 causes the blue light B to be incidentally incident on the scattering plate 730 in a substantially condensed state. The first lens 722 and the second lens 724 are made of a convex lens.

The scattering plate 730 scatters the blue light B from the second light source device 710 with a predetermined scattering degree, and is a blue light B having a light distribution similar to the fluorescent light YL emitted from the rotating fluorescent plate 30. As the scattering plate 730, for example, frosted glass made of optical glass can be used.

The pickup optical system 731 includes lenses 732 and 733. The lenses 732 and 733 are made of convex lenses, respectively. The pickup optical system 731 parallelizes the blue light B scattered by the scattering plate 730 and causes it to enter the lens integrator optical system 740.

The lens integrator optical system 740 has lens arrays 750 and 751. The lens array 750 has a plurality of small lenses 750a for dividing the blue light B into a plurality of partial luminous fluxes. The lens array 751 has a plurality of small lenses 751a corresponding to the plurality of small lenses 750a of the lens array 750. The lens array 751 forms an image of the small lens 750a of the lens array 750 in or near the image forming region of the liquid crystal light modulation device 400B together with the superposed lens 760 in the subsequent stage.

In the present embodiment, the blue light B emitted from the second illumination device 102 is reflected by the reflection mirror 250, passes through the field lens 300B, and is incident on the image forming region of the liquid crystal light modulator 400B for blue light.

As described above, according to the first illumination device 101 of the present embodiment, the illuminance distribution of the illuminated region SA on the phosphor layer 42 is rectangular with a smaller number of parts than when two multi-lens arrays are used. Can be made uniform. Therefore, the fluorescent light YL can be generated with high efficiency.

According to the projector 1 of the present embodiment, since the lighting device 100 including the first lighting device 101 is provided, a bright color image can be displayed on the screen SCR.

(Second Embodiment)
Subsequently, the projector according to the second embodiment will be described. The difference between the present embodiment and the first embodiment is the configuration of the lighting device (first lighting device). In the following, the configuration of the lighting device will be mainly described. The members and parts common to those of the first embodiment are designated by the same reference numerals, and the details thereof will be omitted.

FIG. 4 is a diagram showing a schematic configuration of the first lighting device 201 of the present embodiment. As shown in FIG. 4, the first lighting device 201 includes a first light source device 10, a collimating optical system 15, a photomolding optical system 70, a rotating fluorescent plate 30, a pickup optical system 60, and a first lens array 120. A second lens array 130, a polarization conversion element 140, a superposed lens 150, and a control device 160 are provided.

The collimating optical system 15 has a plurality of collimating lenses 15a. The plurality of collimating lenses 15a are arranged two-dimensionally. Each of the plurality of collimating lenses 15a is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of collimating lenses 15a are arranged in a matrix (for example, 5 rows and 5 columns in FIG. 4). In the present embodiment, the collimating lens 15a corresponds to the "condensing lens" in the claims.

Each of the plurality of collimating lenses 15a parallelizes the corresponding laser beam LB. In the present embodiment, the laser light LB is incident on the photoforming optical system 70 in a state of being converted into parallel light.

The optical molding optical system 70 includes a plurality of lenses 71 arranged in an array. Each of the plurality of lenses 71 is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of lenses 71 are arranged in a matrix (for example, 5 rows and 5 columns).

In the present embodiment, each of the plurality of lenses 71 is composed of a free curved surface lens having a free curved surface. Each of the plurality of lenses 71 forms a spot shape formed by the corresponding laser beam LB on the illuminated region (fluorescent layer 42) and makes the illuminance distribution of the spot uniform.

In the present embodiment, the plurality of lenses 71 include a first lens 71a, a second lens 71b, and a third lens 71c. The first lens 71a corresponds to the first semiconductor laser 11a, the second lens 71b corresponds to the second semiconductor laser 11b, and the third lens 71c corresponds to the third semiconductor laser 11c. Therefore, the laser light LB1 is incident on the first lens 71a, the laser light LB2 is incident on the second lens 71b, and the laser light LB3 is incident on the third lens 71c.

Hereinafter, the structure of the plurality of lenses 71 will be described by taking the first lens 71a as an example. The first lens 71a has a first free curved surface 72a defined by a polynomial with x and y as variables on the light incident surface side, and has a refracting surface 74a on the light emitting surface side. The first free curved surface 72a has a rotationally asymmetrical shape and is defined by the above equation (1).

In the present embodiment, the polynomial defining the first free-form surface 72a satisfies the first condition. Therefore, the spot of the laser beam LB1 can be made rectangular, and the illuminance distribution of the spot can be converted into a so-called top hat distribution to make it uniform.

In the present embodiment, the laser light LB1 incident on the first lens 71a is converted from divergent light to parallel light by the collimating optical system 15. Therefore, the load applied to the first free curved surface 72a is lower than that of the first free curved surface in the first embodiment in which the collimating optical system 15 is not used. Therefore, as compared with the first embodiment, the design conditions of the first free curved surface 72a are relaxed, so that the design of the first lens 71a becomes easy.

The refracting surface 74a is composed of a flat surface (for example, a prism surface) and deflects the laser beam LB1 emitted from the first lens 71a. Thereby, the spot position of the laser beam LB1 can be adjusted.

The polynomial that defines the first free-form surface 72a satisfies the third condition. As a result, it is possible to form a distortion-free spot on the illuminated area by correcting the distortion due to the deflection.

Since the first lens 71a has the above-mentioned refracting surface 74a, it is not necessary for the first free curved surface 72a to deflect the laser beam LB1. That is, the first free curved surface 72a does not satisfy the second condition. Since the first free curved surface 72a does not have a deflection function of the laser beam LB1, the shape design of the lens becomes easy.

Even when the first lens 71a has a refracting surface 74a, the second condition may be satisfied. By doing so, the first free curved surface 72a and the refracting surface 74a each have a refracting power, so that the refraction power of the refracting surface 74a can be reduced.

Further, in the first lens 71a of the present embodiment, the coefficient of the odd-order term of x and the coefficient of the odd-order term of y in the equation (1) are 0, and the coefficient of the term combining x and y is 0. Is. That is, the polynomial is composed of even-ordered terms of x and even-ordered terms of y. Hereinafter, "composing a polynomial with even-numbered terms of x and even-numbered terms of y" may be referred to as a fourth condition.

Since the shape design of the first free curved surface 72a satisfying the fourth condition is easy, the cost can be reduced.

As described above, according to the first lens 71a, a spot SP having a rectangular shape and a uniform illuminance distribution can be formed on the phosphor layer 42. Further, the first lens 71a does not need a function of refracting the laser beam LB1, so that the design is easy.

Similarly, the second lens 71b has a second free curved surface 72b and a refracting surface 74b. The second free curved surface 72b satisfies the first, third, and fourth conditions, and the laser beam LB2 emitted from the second lens 71b has a rectangular and uniform illuminance distribution on the phosphor layer 42. It is designed to form a spot SP. The second free-form surface 72b superimposes the laser light LB2 emitted from the second lens 71b and the laser light LB1 emitted from the first lens 71a on the phosphor layer 42.

Similarly, the third lens 71c has a third free curved surface 72c and a refracting surface 74c. The third free curved surface 72c satisfies the first, third, and fourth conditions, and the laser beam LB3 emitted from the third lens 71c has a rectangular and uniform illuminance distribution on the phosphor layer 42. It is designed to form a spot SP. The third free curved surface 72c superimposes the laser light LB3 on the laser light LB1 and the laser light LB2 on the phosphor layer 42.

In the present embodiment, each of the plurality of lenses 71 except for the first lens 71a, the second lens 71b, and the third lens 71c also has a free curved surface satisfying the first, third, and fourth conditions. .. Therefore, the laser light LB emitted from each lens 71 forms a rectangular spot SP having a uniform illuminance distribution on the phosphor layer 42, and the spot SPs are superimposed on the phosphor layer 42. As a result, the illuminated region SA is formed on the phosphor layer 42 by the plurality of laser light LBs.

If the distortion due to deflection is small, a lens 71 having a free curved surface that satisfies only the first condition and the fourth condition may be adopted. In this case, since it is not necessary to correct the distortion, the design of the lens 71 becomes easy.

Based on such a configuration, the optical molding optical system 70 of the present embodiment can form the spot SP on the phosphor layer 42 into a rectangular shape and can make the illuminance distribution of the spot SP uniform. The collimating optical system 15 can be regarded as a collimating lens array conventionally used for parallelizing each laser beam LB. Therefore, the number of parts can be reduced as compared with the case where two multi-lenses are used in addition to the collimating lens array to make the illuminance distribution uniform.

According to the first illumination device 201 of the present embodiment, the illuminance distribution of the illuminated region SA formed on the phosphor layer 42 is made uniform, so that the fluorescent light YL can be generated with high efficiency.

The positional relationship between the collimating optical system 15 and the photoforming optical system 70 is not limited to the above. For example, the first light source device 10, the photoforming optical system 70, and the collimating optical system 15 may be arranged in this order in the light emitting direction of the first lighting device 201.

Further, a cylindrical lens may be used instead of the collimating optical system 15. Generally, the emission angle of the laser beam LB has anisotropy. Therefore, for example, by preparing a pair of cylindrical lenses having bus lines corresponding to a direction having a small radiation angle and a direction having a large radiation angle, the laser light LB having an anisotropic radiation angle is satisfactorily parallelized and the light is emitted. It can be incident on the molding optical system 70.

(Third Embodiment)
Subsequently, the projector according to the third embodiment will be described. In this embodiment, the configuration of the second lighting device is different. Hereinafter, the configuration of the second lighting device will be mainly described. The members and parts common to those of the first embodiment are designated by the same reference numerals, and the details thereof will be omitted.

FIG. 5 is a schematic view showing a second lighting device of the projector according to the present embodiment. As shown in FIG. 5, the second lighting device 202 of the present embodiment includes a second light source device 710 and an optical molding optical system 20. The second light source device 710 has the same configuration as the first light source device 10 of the first lighting device 101, and has a plurality of semiconductor lasers 11. In the present embodiment, the second light source device 710 emits blue light B composed of a plurality of laser light LBs toward the photoforming optical system 20.

Similar to the first illuminating device 101, the second illuminating device 202 constitutes each of the blue light B so as to make the illuminance distribution on the liquid crystal light modulator 400B which is the illuminated region uniform by the optical molding optical system 20. The laser light LB is incident on the liquid crystal light modulator 400B.

According to the second illumination device 202 of the present embodiment, the number of parts is smaller than that of the lens integrator optical system 740 using two multi-lens arrays, but the blue color incident on the liquid crystal light modulator 400B, which is the illuminated area. The illuminance distribution of light B can be made uniform.

(Fourth Embodiment)
Subsequently, the first lighting device according to the fourth embodiment will be described. The difference between the present embodiment and the second embodiment is the configuration of the optical molding optical system. Hereinafter, the configuration of the optical molding optical system will be mainly described. The members and parts common to the second embodiment are designated by the same reference numerals, and the details thereof will be omitted.

FIG. 6 is a diagram showing a schematic configuration of the first lighting device 301 of the present embodiment. As shown in FIG. 6, the first illumination device 301 includes a first light source device 10, a collimating optical system 15, an optical molding optical system 170, a rotating fluorescent plate 30, a pickup optical system 60, and a first lens array 120. A second lens array 130, a polarization conversion element 140, a superposed lens 150, and a control device 160 are provided.

The optical molding optical system 170 includes a plurality of optical members 171 arranged in an array. Each of the plurality of optical members 171 is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of optical members 171 are arranged in a matrix (for example, 5 rows and 5 columns).

In the present embodiment, each of the plurality of optical members 171 is made of glass in which a light incident surface 175, a light emitting surface 176, and a reflecting surface 177 are integrally formed. The light emitting surface 176 is composed of a lens surface having a free curved surface. Each of the plurality of optical members 171 forms a spot shape formed by the corresponding laser beam LB on the illuminated region (fluorescent layer 42) and makes the illuminance distribution of the spot uniform.

In the present embodiment, the plurality of optical members 171 include a first optical member 171a, a second optical member 171b, and a third optical member 171c. The first optical member 171a corresponds to the first semiconductor laser 11a, the second optical member 171b corresponds to the second semiconductor laser 11b, and the third optical member 171c corresponds to the third semiconductor laser 11c. .. Therefore, the laser light LB1 is incident on the first optical member 171a, the laser light LB2 is incident on the second optical member 171b, and the laser light LB3 is incident on the third optical member 171c.

Hereinafter, the structure of the first optical member 171a among the plurality of optical members 171 will be described by taking as an example. The first optical member 171a has a light incident surface 175a, a light emitting surface 176a, and a reflecting surface 177a. In FIG. 6, only the main light beam of the laser beam LB incident on each optical member 171 is shown for easy viewing.

The light incident surface 175a is composed of a flat surface (for example, a prism surface). The main ray LB1c of the laser beam LB1 is incident on the light incident surface 175a in the plane normal direction. Therefore, when passing through the light incident surface 175a, the traveling direction of the main ray LB1c of the laser light LB1 does not change due to refraction.

The laser beam LB1 that has passed through the light incident surface 175a and is incident on the first optical member 171a is incident on the reflecting surface 177a. The reflective surface 177a is formed of, for example, a metal vapor deposition film. The configuration of the reflecting surface 177a is not particularly limited, and may be configured by, for example, a total reflecting surface that totally reflects the laser light LB1. The reflecting surface 177a deflects the traveling direction of the laser light LB1 by reflecting the laser light LB1 transmitted through the light incident surface 175a. As a result, the spot position of the laser beam LB1 on the illuminated area is adjusted.

The laser beam LB1 reflected by the reflecting surface 177a is incident on the light emitting surface 176a. The light emitting surface 176a is composed of a first lens surface 178a. The first lens surface 178a has a first free curved surface 172a defined by a polynomial with x and y as variables. The first free curved surface 172a has a rotationally asymmetrical shape and is defined by the above equation (1).

In the present embodiment, the polynomial defining the first free-form surface 172a satisfies the first condition. Therefore, the spot of the laser beam LB1 can be made rectangular, and the illuminance distribution of the spot can be converted into a so-called top hat distribution to make it uniform.

In the present embodiment, the laser light LB1 incident on the first free curved surface 172a is converted from divergent light to parallel light by the collimating optical system 15. Therefore, the load applied to the first free-form surface 172a is lower than that of the first free-form surface in the first embodiment in which the collimating optical system 15 is not used, and the design conditions of the first free-form surface 172a are relaxed.

In the present embodiment, it is desirable that the polynomial defining the first free-form surface 172a satisfies the above-mentioned third condition. As a result, a distortion-free spot can be formed on the illuminated area by correcting the distortion caused by the deflection caused by the reflecting surface 177a.

Here, when the refraction of the lens surface is used as a means for deflecting the traveling direction of the laser light, the refractive index may fluctuate due to a temperature change of the lens glass material. When the refractive index of the lens glass material fluctuates, the direction of travel of light due to the refraction of the lens surface varies. Therefore, the spot formation position on the illuminated area may be displaced, and the illuminated area may not be efficiently illuminated.

On the other hand, since the first optical member 171a of the present embodiment has the above-mentioned reflecting surface 177a, it is not necessary to deflect (refract) the laser beam LB1 on the first free curved surface 172a. That is, the first free curved surface 172a does not have a refraction function (deflection function) for refracting the laser beam LB1. That is, the first free curved surface 172a does not have to satisfy the above-mentioned second condition.

Therefore, according to the first optical member 171a of the present embodiment, the light is deflected by using the reflection by the reflecting surface 177a instead of the refraction by the lens surface. Further, the laser light LB1 is not refracted when it is incident from the light incident surface 175a. Therefore, even if the refractive index fluctuates due to a temperature change, the refraction of light is not used as described above, so that the direction of travel of the laser beam LB1 is unlikely to vary. Therefore, since the spot formation position on the illuminated area is unlikely to shift, the spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42.

Similarly, the second optical member 171b has a light incident surface 175b, a light emitting surface 176b, and a reflecting surface 177b. The light incident surface 175b is composed of a second lens surface 178b. The second lens surface 178b has a second free curved surface 172b. The second free-form surface 172b satisfies the first and third conditions, and the spot SP in which the laser beam LB2 emitted from the second optical member 171b has a rectangular and uniform illuminance distribution on the phosphor layer 42. Is designed to form. The second free-form surface 172b superimposes the laser light LB2 emitted from the second optical member 171b and the laser light LB1 emitted from the first optical member 171a on the phosphor layer 42. Since the second optical member 171b does not utilize the refraction of light, it is unlikely that the direction of travel of the laser beam LB2 will vary. Therefore, a spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42.

Similarly, the third optical member 171c has a light incident surface 175c, a light emitting surface 176c, and a reflecting surface 177c. The light incident surface 175c is composed of a third lens surface 178c. The third lens surface 178c has a third free curved surface 172c. The third free curved surface 172c satisfies the first and third conditions, and the spot SP in which the laser beam LB3 emitted from the third optical member 171c has a rectangular and uniform illuminance distribution on the phosphor layer 42. Is designed to form. The third free curved surface 172c superimposes the laser light LB3 on the laser light LB1 and the laser light LB2 on the phosphor layer 42. Since the third optical member 171c does not utilize the refraction of light, it is unlikely that the direction of travel of the laser beam LB3 will vary. Therefore, a spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42.

In the present embodiment, each of the plurality of optical members 171 except for the first optical member 171a, the second optical member 171b, and the third optical member 171c also has a free curved surface satisfying the first and third conditions. There is. Therefore, the laser light LB emitted from each optical member 171 forms a rectangular spot SP having a rectangular and uniform illuminance distribution on the phosphor layer 42, and the spot SPs overlap each other on the phosphor layer 42. As a result, the illuminated region SA is formed on the phosphor layer 42 by the plurality of laser light LBs. The optical member 171 that does not deflect the traveling direction of the laser light LB (for example, the optical member 171 located on the illumination optical axis 100ax) has only a light incident surface 175 and a light emitting surface 176, and has a reflecting surface 177. Not done.

Since refraction is not used in each of the plurality of optical members 171 to deflect the light, variation in the traveling direction of the laser beam LB is unlikely to occur even if the refractive index of the glass material fluctuates. Therefore, according to the optical molding optical system 170 of the present embodiment, the illuminated region SA having a rectangular shape and a uniform illuminance distribution can be accurately formed on the phosphor layer 42.

According to the first illumination device 301 of the present embodiment, since a uniform illuminated region SA can be formed in the phosphor layer 42, fluorescent light YL can be generated with high efficiency.

In the present embodiment, the case where the light incident surface 175, the light emitting surface 176, and the reflecting surface 177 are integrally formed as the optical member 171 is given as an example, but each may be formed separately.

For example, the optical member may be configured by using a free curved lens having a light emitting surface 176 and a holding member holding the free curved lens and the reflecting surface 177. In this case, the number of parts can be reduced by forming the reflective surface 177 on a part of the holding member. The light incident surface 175 made of a flat plate can be omitted.

Further, the portion of the optical member 171 other than the light incident surface 175 and the reflecting surface 177 that affect the laser light LB may be formed of an air layer. That is, a hollow structure may be provided in the middle of the optical path of the laser beam LB passing through the optical member 171.
As a portion where the hollow structure can be adopted, for example, in the optical path of the laser light LB, the path from the light incident surface 175 to the reflecting surface 177, or the light emitted after being reflected by the reflecting surface 177. An example can be illustrated of a portion corresponding to the path leading to the incident on the surface 176.

(Fifth Embodiment)
Subsequently, the first lighting device according to the fifth embodiment will be described. The difference between the present embodiment and the fourth embodiment is the configuration of the optical molding optical system. Hereinafter, the configuration of the optical molding optical system will be mainly described. The members and parts common to the fourth embodiment are designated by the same reference numerals, and the details thereof will be omitted.

FIG. 7 is a diagram showing a schematic configuration of the first lighting device 401 of the present embodiment. As shown in FIG. 7, the first illumination device 401 includes a first light source device 10, a collimating optical system 15, an optical molding optical system 270, a rotating fluorescent plate 30, a pickup optical system 60, and a first lens array 120. A second lens array 130, a polarization conversion element 140, a superposed lens 150, and a control device 160 are provided.

The optical molding optical system 270 includes a plurality of optical members 271 arranged in an array. Each of the plurality of optical members 271 is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of optical members 171 are arranged in a matrix (for example, 5 rows and 5 columns).

In this embodiment, each of the plurality of optical members 271 has a light incident surface 275, a light emitting surface 276, and a reflecting surface 277. The light incident surface 275 is composed of a lens surface having a free curved surface. Each of the plurality of optical members 271 forms a spot shape formed by the corresponding laser beam LB on the illuminated region (fluorescent layer 42) and makes the illuminance distribution of the spot uniform.

In the present embodiment, the plurality of optical members 271 include a first optical member 271a, a second optical member 271b, and a third optical member 271c. The first optical member 271a corresponds to the first semiconductor laser 11a, the second optical member 271b corresponds to the second semiconductor laser 11b, and the third optical member 271c corresponds to the third semiconductor laser 11c. .. Therefore, the laser light LB1 is incident on the first optical member 271a, the laser light LB2 is incident on the second optical member 271b, and the laser light LB3 is incident on the third optical member 271c.

Hereinafter, the structure of the first optical member 271a among the plurality of optical members 271 will be described as an example. The first optical member 271a has a light incident surface 275a, a light emitting surface 276a, and a reflecting surface 277a. In FIG. 7, only the main light beam of the laser beam LB incident on each optical member 271 is shown for easy viewing.

The light incident surface 275a is composed of a first lens surface 278a. The first lens surface 278a has a first free curved surface 272a defined by a polynomial with x and y as variables. The first free curved surface 272a has a rotationally asymmetrical shape and is defined by the above equation (1).

In the present embodiment, the polynomial defining the first free-form surface 272a satisfies the first condition. Therefore, the spot of the laser beam LB1 can be made rectangular, and the illuminance distribution of the spot can be converted into a so-called top hat distribution to make it uniform.

In the present embodiment, the laser light LB1 incident on the first free curved surface 272a is converted from divergent light to parallel light by the collimating optical system 15. Therefore, the load applied to the first free-form surface 272a is lower than that of the first free-form surface in the first embodiment in which the collimating optical system 15 is not used, and the design conditions of the first free-form surface 272a are relaxed.

The reflecting surface 277a is formed of, for example, a metal vapor deposition film, and reflects the laser light LB1 transmitted through the light incident surface 275a to deflect the traveling direction of the laser light LB1. As a result, the spot position of the laser beam LB1 on the illuminated area is adjusted.

The light emitting surface 276a is composed of a flat surface (for example, a prism surface). The main ray LB1c of the laser beam LB1 is incident on the light emitting surface 276a in the plane normal direction. Therefore, when the light is emitted from the light emitting surface 276a, the traveling direction of the main ray LB1c of the laser light LB1 does not change due to refraction.

In the present embodiment, it is desirable that the polynomial defining the first free-form surface 272a satisfies the above-mentioned third condition. As a result, a distortion-free spot can be formed on the illuminated area by correcting the distortion caused by the deflection caused by the reflecting surface 277a.

In the first optical member 271a of the present embodiment, the light is deflected by using the reflection by the reflecting surface 277a instead of the refraction by the lens surface, and the laser light LB1 is not refracted when emitted from the light emitting surface 276a. Therefore, even if the refractive index of the glass material fluctuates due to a temperature change, the direction of travel of the laser beam LB1 is unlikely to vary. Therefore, since the spot formation position on the illuminated area is unlikely to shift, the spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42.

Similarly, the second optical member 271b has a light incident surface 275b, a light emitting surface 276b, and a reflecting surface 277b. The light incident surface 275b is composed of a second lens surface 278b. The second lens surface 278b has a second free curved surface 272b. The second lens surface 278b satisfies the first and third conditions, and the spot SP in which the laser beam LB2 emitted from the second optical member 271b has a rectangular and uniform illuminance distribution on the phosphor layer 42. Is designed to form. Since the second optical member 271b does not utilize the refraction of light, it is difficult for the laser light LB2 to vary in the traveling direction, and the spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42. ..

Similarly, the third optical member 271c has a light incident surface 275c, a light emitting surface 276c, and a reflecting surface 277c. The light incident surface 275c is composed of a third lens surface 278c. The third lens surface 278c has a third free curved surface 272c. The third free curved surface 272c satisfies the first and third conditions, and the spot SP in which the laser beam LB3 emitted from the third optical member 271c has a rectangular and uniform illuminance distribution on the phosphor layer 42. Is designed to form. Since the third free curved surface 272c does not utilize the refraction of light, it is difficult for the laser light LB3 to vary in the traveling direction, and the spot SP having a rectangular shape and a uniform illuminance distribution can be efficiently formed on the phosphor layer 42. ..

In the present embodiment, each of the plurality of optical members 271 except for the first optical member 271a, the second optical member 271b, and the third optical member 271c also has a free curved surface satisfying the first and third conditions. There is. Since refraction is not used in each of the plurality of optical members 271 to deflect the light, variation in the traveling direction of the laser beam LB is unlikely to occur even if the refractive index of the glass material fluctuates. Therefore, according to the optical molding optical system 270 of the present embodiment, the illuminated region SA having a rectangular shape and a uniform illuminance distribution can be accurately formed on the phosphor layer 42. The optical member 271 (for example, the optical member 271 located on the illumination optical axis 100ax) that does not deflect the traveling direction of the laser light LB has only a light incident surface 275 and a light emitting surface 276, and has a reflecting surface 277. Not done.

According to the first illumination device 401 of the present embodiment, since a uniform illuminated region SA can be formed in the phosphor layer 42, fluorescent light YL can be generated with high efficiency.

(Sixth Embodiment)
Subsequently, the first lighting device according to the sixth embodiment will be described. The difference between the present embodiment and the fifth embodiment is the configuration of the optical molding optical system. Hereinafter, the configuration of the optical molding optical system will be mainly described. The members and parts common to the fourth embodiment are designated by the same reference numerals, and the details thereof will be omitted.

FIG. 8 is a diagram showing a schematic configuration of the first lighting device 501 of the present embodiment. As shown in FIG. 8, the first lighting device 501 includes a first light source device 10, an optical molding optical system 370, a rotating fluorescent plate 30, a pickup optical system 60, a first lens array 120, and a second lens array. It includes 130, a polarization conversion element 140, a superimposing lens 150, and a control device 160.

The optical molding optical system 370 includes a plurality of optical members 371 arranged in an array. Each of the plurality of optical members 371 is arranged corresponding to each of the plurality of semiconductor lasers 11. That is, the plurality of optical members 171 are arranged in a matrix (for example, 5 rows and 5 columns).

In this embodiment, each of the plurality of optical members 371 has a light incident surface 375, a light emitting surface 276, and a reflecting surface 277. The light incident surface 375 is composed of a lens surface having a free curved surface. In FIG. 8, only the main light beam of the laser beam LB incident on each optical member 371 is shown for easy viewing.

The light incident surface 375 is composed of a lens surface having a free curved surface defined by the polynomial of the above equation (1) with x and y as variables. In the present embodiment, the light incident surface 375 is also designed to function as a collimating lens that parallelizes the laser light LB emitted from the corresponding semiconductor laser 11. Therefore, the first illuminating device 501 of the present embodiment has a configuration in which the function of the collimating optical system 15 in the first illuminating device 401 of the fifth embodiment is also combined with the optical molding optical system 370.

According to the first lighting device 501 of the present embodiment, the collimating optical system can be omitted, so that the device configuration can be miniaturized.

In each of the above embodiments, the case where each of the plurality of laser light LBs illuminates the entire surface of the illuminated area and each laser light LB illuminates in a superimposed manner has been described as an example. Not limited.

(First modification)
The optical molding optical system 20 of this modification is configured so that each spot SP is incident on different regions of the illuminated region SA. That is, in this modification, unlike the above-described embodiment, the spots SP are not superimposed.

For example, the first lens 21a and the second lens 21b have a spot position formed by the laser light LB1 on the illuminated area SA and a spot position formed by the laser light LB2 on the illuminated area SA. The free curved surfaces 22a and 22b are designed so as to be different.

FIG. 9 is a diagram conceptually showing a modified example of the illumination method in the illuminated area. In FIG. 9, the number of spots SP formed by the laser beam LB on the phosphor layer 42 is set to n. In FIG. 9, each of the n spots SP is shown as _{SP 1} , SP ₂ , ... SP _{n, respectively.}

Each of the spots SP has a rectangular shape and has a uniform illuminance distribution. Therefore, the illuminated region SA composed of n spots SP has a uniform illuminance distribution as a whole.

Further, according to this modification, since the spots are not superimposed, the illuminated area SA of an arbitrary size can be illuminated by appropriately adjusting the size of each spot.

Further, according to this modification, the positions of the spots SP are different from each other in the illuminated area SA. Therefore, when the illuminated region SA is the phosphor layer 42, the intensity per unit area of the irradiated light is smaller than that in the case where each spot SP is superimposed as in the first embodiment. As a result, the light intensity per unit area of the phosphor layer 42 is reduced, so that the fluorescent light YL can be generated with higher efficiency.

In this modification, the output of each laser beam LB can be controlled independently by the control device 160. When the illuminated area SA is a light modulation device such as a liquid crystal light modulation device, in this way, the illuminance distribution of the illuminated area SA formed in the light modulation device can be adjusted according to the image to be displayed. The image quality can be improved.

(Second modification)
FIG. 10 is a diagram conceptually showing a modified example of the illumination method in the illuminated area. In FIG. 10, the number of spots SP formed by the laser beam on the phosphor layer 42 is set to n. In FIG. 10, each of the n spots SP is shown as _{SP 1} , SP ₂ , ... SP _{n, respectively.}

In this modification, the spot SP is partially superimposed in the illuminated area SA. As shown in FIG. 7, the illuminated area SA is composed of a plurality of illuminated areas SB including a first illuminated area SB1 and a second illuminated area SB2. At least one illumination region SB out of the plurality of illumination region SBs is formed by superimposing two spots SP. The other illumination area SB may be formed by one spot SP.

In this modification, the first illumination region SB1 is configured by, for example, superimposing the _{spot SP 1} and the spot SP _2. Further, the second illumination region SB2 is configured by superimposing _{two other laser beams (spot SP n-1} and spot SP _n).

In this modification, since each of the spots SP has a uniform illuminance distribution, each illumination region SB has a uniform illuminance distribution. Therefore, the illuminated region SA composed of the plurality of illuminated regions SB has a uniform illuminance distribution and has the same effect as that of the first modification.

(Third modification example)
FIG. 11 is a diagram conceptually showing a modified example of the illumination method in the illuminated area. In FIG. 11, the number of spots SP formed by the laser beam on the phosphor layer 42 is set to n. In FIG. 11, each of the n spots SP is shown as _{SP 1} , SP ₂ , ... SP _{n, respectively.}

In the optical molding optical system 20 according to this modification, the third lens 21c (third free curved surface 22c) causes the laser beam LB3 to be incident on the entire surface of the illuminated region SA. Further, the first lens 21a (first free curved surface 22a) causes the laser beam LB1 to be incident on a part of the illuminated region SA. Further, the second lens 21b (second free curved surface 22b) causes the laser light LB2 to be incident on a part of the illuminated region SA (a region different from the incident region of the laser light LB1).

In this modification, the control device 160 controls the output of the first semiconductor laser 11a and the output of the second semiconductor laser 11b independently of each other. That is, the control device 160 sets each spot SP to a desired illuminance distribution by controlling the output of each semiconductor laser 11.

In the optical molding optical system 20 of the present embodiment, as shown in FIG. 11, one spot SP ₃ irradiates the entire surface of the illuminated area SA, and the remaining (n-1) spots excluding the _{spot SP 3 are spots.} The SP is configured to be incident on different regions of the illuminated region SA.

Also in this modified example, since each of the spot SPs has a uniform illuminance distribution, the same effect as that of the first modified example can be obtained.

The present invention is not limited to the contents of the above-described embodiments and modifications, and can be appropriately modified as long as the gist of the invention is not deviated.

For example, in the above embodiment, the case where the first light source device 10 is composed of a plurality of semiconductor lasers 11 has been given as an example, but the present invention is not limited to this. For example, the first light source device 10 may be composed of only one semiconductor laser 11 (for example, the first semiconductor laser 11a). At this time, the optical molding optical system 20 has only the first lens 21a.

In the above embodiment, the superimposition has been described as a state in which the entire spots SP of each laser beam LB are substantially overlapped, but in the present invention, the superimposition also includes a state in which a part of each spot SP is overlapped with each other.

That is, the first light source device 10 is composed of two semiconductor lasers 11 (for example, the first semiconductor laser 11a and the second semiconductor laser 11b), and is emitted from the first semiconductor laser 11a and the second semiconductor laser 11b. It is assumed that the incident positions of the laser beams LB1 and B2 are slightly deviated from each other due to a mounting error. At this time, a partially overlapping region (overlapping region) of the spots SP formed by the laser beams LB1 and B2 constitutes an illuminated region.

Further, in the above embodiment, the projector 1 provided with three liquid crystal light modulators 400R, 400G, and 400B is exemplified as the optical modulator, but it can also be applied to a projector that displays a color image with one liquid crystal optical modulator. Is. Further, a digital mirror device may be used as the optical modulation device.

In the above embodiment, an example in which the lighting device according to the present invention is mounted on a projector is shown, but the present invention is not limited to this. The lighting device according to the present invention can also be applied to lighting equipment, automobile headlights, and the like.

The present inventor has performed a simulation on a lens constituting an optical molding optical system. In this simulation, the coefficient of the polynomial of the above equation (1) that defines the free curved surface of the lens was used as a parameter, and the illuminance distribution in the illuminated region when each free curved surface was used was obtained.

(Example 1)
In the first embodiment, the first condition (the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h ) and the second condition (the first-order term of x and the first-order term of y). among the simulation results of a lens having a free curved surface which satisfies at least one comprises a) and the third condition (including at least one term of x ^p y ^q). That is, the lens of the first embodiment corresponds to the lens 21 constituting the optical molding optical system 20 of the first embodiment satisfying the first to third conditions.

Table 1 shows each parameter of Example 1.

In Example 1, in the formula (1), -0.35 coefficients of terms x and y, -0.02 a coefficient of the term ^{x 2,} 0.008 coefficient of xy sections term ^{y 2} the coefficient 0.02, -0.002 the coefficient of the term ^{x 4, x 3} the coefficient of the term of y 0, ^{y 4} of the coefficients of the terms -0.08, curvature c 0.029, conic constant k was set to 0. The coefficients of the terms not listed in Table 1 are all 0.

12A and 12B are diagrams showing the simulation results of the first embodiment. FIG. 12A is a diagram showing an illuminance distribution when a spherical lens is used for comparison, and FIG. 12B is a diagram showing an illuminance distribution when a free-form surface lens having the above parameters (first condition to third condition) is used. be. In FIGS. 12A and 12B, the graph shown on the lower side is the illuminance distribution in the left-right direction of the illuminated area, and the graph shown on the right side is the illuminance distribution in the vertical direction of the illuminated area.

As shown in FIG. 12A, when a spherical lens is used, the laser beam forms an elliptical spot in the illuminated area, and the illuminance distribution of the spot becomes non-uniform.
On the other hand, as shown in FIG. 12B, when the free-form surface lens of Example 1 is used, the laser beam forms a substantially rectangular spot in the illuminated area, and the uniformity of the illuminance distribution of the spot is improved. That is, from Example 1, it was confirmed that by adopting a free-form surface lens that satisfies the first condition and the second condition, the illuminated area can be formed into a rectangular shape and the illuminance distribution can be made uniform.

(Example 2)
The second embodiment is a simulation result of a lens having a free curved surface satisfying the first to third conditions as in the first embodiment.

Table 2 shows each parameter of Example 2.

In Example 2, in formula (1), -0.25 a coefficient of the term x, -0.75 coefficients of terms of y, -0.01 a coefficient of the term ^{x 2,} the coefficient of xy section The coefficient of the term of y ² is -0.012, the coefficient of the term of x ⁴ is -0.001, the coefficient of the term of x ³ y is 0.001, and the coefficient of the term of ^{y 4 is 0.} 02, the coefficient c was 0.01, and the conic constant k was 0. The coefficients of the terms not listed in Table 2 are all 0.

13A and 13B are diagrams showing the simulation results of the second embodiment. FIG. 13B is a diagram showing an illuminance distribution when a free-form surface lens having the above parameters is used, and FIG. 13A is a diagram showing an illuminance distribution when all the coefficients other than the X coefficient and the Y coefficient are set to 0 as a comparative example. It is a figure which shows. In FIGS. 13A and 13B, the graph shown on the lower side is the illuminance distribution in the left-right direction of the illuminated area, and the graph shown on the right side is the illuminance distribution in the vertical direction of the illuminated area.

As shown in FIGS. 13A and 13B, when a free-form surface lens satisfying the first condition and the second condition is used, a rectangular spot having a uniform illuminance distribution is formed in the illuminated area. As described above, from Example 2, it was confirmed that by adopting the free-form surface lens satisfying the first condition and the second condition, the illuminated area can be formed into a rectangular shape and the illuminance distribution can be made uniform.

(Example 3)
Example 3 is a simulation result of a lens having a free curved surface satisfying the first condition and the third condition. That is, the lens of the third embodiment corresponds to the lens 71 constituting the optical molding optical system 70 of the second embodiment satisfying the first condition and the third condition.

Table 3 shows each parameter of Example 3.

In Example 3, in formula (1), -0.02 coefficients of x and y of the coefficient 0, ^{x 2} term sections 0.008 coefficient of xy sections the coefficient of the term of ^{y 2} 0.02, -0.002 the coefficient of the term ^{x 4, x 3} the coefficient of the term of y 0, ^{y 4} of the coefficients of the terms -0.08, curvature c 0.029, the conic constant k 0 And said. The coefficients of the terms not listed in Table 3 are all 0.

Example 3 is the same as the parameters of Example 1 except that the coefficients of the terms x and y are set to 0. That is, the free curved surface of the third embodiment and the free curved surface of the first embodiment differ only in the presence or absence of the function of deflecting light. The function of deflecting light does not affect the shape of the spot formed on the illuminated area and the illuminance distribution of the spot.

If the free-form surface lens of the third embodiment is adopted, the same illuminance distribution as in FIG. 12B of the first embodiment can be realized. That is, it was confirmed that the illuminated area can be formed into a rectangular shape and the illuminance distribution can be made uniform. The figure showing the illuminance distribution according to the third embodiment is the same as that of the first embodiment, and is therefore omitted.

(Example 4)
The fourth embodiment is a simulation result of a lens having a free curved surface satisfying the first condition and the third condition as in the third embodiment.

Table 4 shows each parameter of Example 4.

In Example 4, in the formula (1), -0.01 coefficients of the coefficient of the term x and y 0, ^{x 2} term, 0.006 coefficient of xy sections the coefficient of the term of ^{y 2} -0.012, -0.001 and coefficient of the term ^{x 4, x 3} coefficient 0.001 of y terms, 0.02 coefficient of the term of ^{y 4,} 0.01 curvature c, conic constant k Was set to 0. The coefficients of the terms not listed in Table 4 are all 0.

Example 4 is the same as the parameters of Example 2 except that the coefficients of the terms x and y are set to 0. That is, the free curved surface of the fourth embodiment and the free curved surface of the second embodiment differ only in the presence or absence of the function of deflecting light.

If the free-form surface lens of the fourth embodiment is adopted, the same illuminance distribution as in FIG. 13B of the second embodiment can be realized. That is, it was confirmed that the illuminated area can be formed into a rectangular shape and the illuminance distribution can be made uniform. The figure showing the illuminance distribution according to the fourth embodiment is the same as that of the second embodiment, and is therefore omitted.

(Example 5)
The fifth embodiment is a simulation result of a lens having a free curved surface satisfying the first condition and the fourth condition (a polynomial is composed of even-numbered terms of x and even-numbered terms of y). That is, the lens of Example 5 corresponds to the lens 71 constituting the optical molding optical system 70 of the second embodiment satisfying the first condition and the fourth condition.

Table 5 shows each parameter of Example 5.

In Example 5, in formula (1), 0.1 the coefficient of the term ^{x 2,} -0.02 a coefficient of the term of ^{y 2,} -0.13 a coefficient of the term ^{x 4,} term ^{x 6} The coefficient of was 0.01, the curvature c was 0.125, and the conic constant k was 0. The coefficients of the items not listed in Table 5 are all 0.

14A and 14B are diagrams showing the simulation results of Example 5. FIG. 14A is a diagram showing an illuminance distribution when a spherical lens is used for comparison, and FIG. 14B is a diagram showing an illuminance distribution when a free curved lens having the above parameters is used. In FIGS. 14A and 14B, the graph shown on the lower side is the illuminance distribution in the left-right direction of the illuminated area, and the graph shown on the right side is the illuminance distribution in the vertical direction of the illuminated area.

As shown in FIG. 14A, in the comparative example, the laser beam forms vertically elongated spots in the illuminated area, and the illuminance distribution of the spots becomes non-uniform.
On the other hand, as shown in FIG. 14B, when the free-form surface lens of Example 5 is used, the laser beam forms a square spot in the illuminated area, and the illuminance distribution of the spot becomes highly uniform. That is, from Example 5, even when a free-form surface lens whose shape can be easily designed by satisfying the first condition and the fourth condition is adopted, the illuminated area can be formed into a square shape and the illuminance distribution can be made uniform. It could be confirmed.

(Example 6)
Example 6 is a simulation result of a lens having a free curved surface satisfying the first condition and the fourth condition as in the fifth embodiment.

Table 6 shows each parameter of Example 6.

In Example 6, in the formula (1), 0.1 the coefficient of the term ^{x 2,} -0.02 a coefficient of the term of ^{y 2,} -0.11 a coefficient of the term ^{x 4,} term ^{x 6} The coefficient of was 0, the curvature c was 0.125, and the conic constant k was 0. The coefficients of the terms not listed in Table 6 are all 0.

15A and 15B are diagrams showing the simulation results of Example 6. FIG. 15A is a diagram showing an illuminance distribution when a spherical lens is used for comparison, and FIG. 15B is a diagram showing an illuminance distribution when a free-form surface lens having the above parameters is used. In FIGS. 15A and 15B, the graph shown on the lower side is the illuminance distribution in the left-right direction of the illuminated area, and the graph shown on the right side is the illuminance distribution in the vertical direction of the illuminated area.

As shown in FIGS. 15A and 15B, when a free-form surface lens satisfying the first condition and the fourth condition is used, a square spot having a uniform illuminance distribution is formed in the illuminated area. As described above, from Example 6, even when a free-form surface lens whose shape design is easy by satisfying the first condition and the fourth condition is adopted, the illuminated area can be formed into a square shape and the illuminance distribution can be made uniform. Was confirmed.

In Examples 5 and 6, the coefficients of the terms in which X and Y are combined are all 0. In this case, since the curvature of the lens can be designed independently in the x direction and the y direction, the lens design is easy.

1 ... Projector, 10 ... First light source device, 11a ... First semiconductor laser, 11b ... Second semiconductor laser, 11c ... Third semiconductor laser, 20 ... Photomolding optical system, 21a ... First lens, 21b ... 2nd lens, 21c ... 3rd lens, 22a ... 1st free curved surface, 22b ... 2nd free curved surface, 22c ... 3rd free curved surface, 42 ... phosphor layer, 70 ... photoformed optical system, 71a ... 1st lens, 71b ... 2nd lens, 71c ... 3rd lens, 72a ... 1st free curved surface, 72b ... 2nd free curved surface, 72c ... 3rd free curved surface, 101 ... 1st illumination Device, 102 ... second lighting device, 160 ... control device, 201 ... first lighting device, 202 ... second lighting device, 400B, 400G, 400R ... liquid crystal light modulator, 600 ... projection optical system, 710 ... second light source Device, LB1 ... laser light, LB2 ... laser light, LB3 ... laser light, SA ... illuminated area.

Claims (18)

A light source device including a first light emitting element that emits a first bundle of light rays, and
An optical molding optical system including a first lens surface to which the first light beam flux is incident is provided.
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
The coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.
The equation (1) includes at least one of a first-order term of x and a first-order term of y.
p, when the q is a positive integer, containing at least one lighting device to the section x ^p y ^q.

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. A light source device including a first light emitting element that emits a first bundle of light rays, and
A photomolding optical system including a first lens surface on which the first light beam flux is incident and a refracting surface that deflects the traveling direction of the first light beam bundle is provided.
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
The refracting surface is a flat surface.
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
The coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.
Before following formula (1) is, p, when the q is a positive ^integer, containing at least one lighting device to the section x p ^{y q.}

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. The illuminating device according to claim 2, wherein the polynomial included in the equation (1) is an even-order term of x and an even-order term of y. A light source device including a first light emitting element that emits a first bundle of light rays, and
An optical molding optical system including a first lens surface on which the first light beam flux is incident, and a reflection surface that reflects the first light beam bundle and deflects the traveling direction of the first light beam bundle. Prepare,
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
The coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.
Formula (1) is, p, when the q is a positive ^integer, containing at least one lighting device to the section x p ^{y q.}

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. The lighting device according to claim 4, wherein the polynomial included in the equation (1) is an even-order term of x and an even-order term of y. The photoforming optical system has a light incident surface and a light emitting surface, and has a light incident surface and a light emitting surface.
One of the light incident surface and the light emitting surface is composed of the first lens surface.
The illuminating device according to claim 4 or 5, wherein the main light beam of the first light beam bundle is incident on the light incident surface and the other side of the light emitting surface in the plane normal direction. A light source device including a first light emitting element that emits a first bundle of light rays, and
An optical molding optical system including a first lens surface on which the first light beam flux is incident, and
A condensing lens provided on the optical path of the first light beam bundle between the first light emitting element and the first lens surface is provided.
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
A lighting device in which the coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. The lighting device according to any one of claims 1 to 7, further comprising a wavelength conversion element into which the first light beam bundle transmitted through the photoforming optical system is incident. A light source device including a first light emitting element that emits a first light beam bundle and a second light emitting element that emits a second light beam bundle.
A photomolding optical system including a first lens surface on which the first light beam flux is incident and a second lens surface on which the second light beam bundle is incident is provided.
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
The second lens surface has a second free curved surface represented by the formula (1).
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
The coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.
With respect to the second free-form surface, the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h.
The photoforming optical system is an illuminating device in which the first light beam bundle and the second light beam bundle illuminate an illuminated area in an overlapping manner.

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. The lighting device according to claim 9, further comprising a light source control device that controls the output of the first light emitting element independently of the output of the second light emitting element. Equipped with a wavelength conversion element
The lighting device according to claim 9 or 10, wherein the predetermined region of the wavelength conversion element corresponds to the illuminated region. A light source device including a first light emitting element that emits a first light beam bundle and a second light emitting element that emits a second light beam bundle.
A photomolding optical system including a first lens surface on which the first light beam flux is incident and a second lens surface on which the second light beam bundle is incident is provided.
The first lens surface has a first free curved surface represented by the equation (1) having x and y as variables.
The second lens surface has a second free curved surface represented by the formula (1).
In the above equation (1), when m = 2h, n = 2h, and h is a positive integer,
The coefficient C _j of the term x ^2h is different from the coefficient C _j of the term y ^2h.
With respect to the second free-form surface, the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h.
The photoforming optical system is a lighting device configured so that the first light beam bundle and the second light beam bundle are incident on different regions of an illuminated region.

In the formula (1), m, n is an integer of 0 or more, k is the conic constant, c is the curvature, _{c j} is the coefficient of ^{x m y n, j = [} (m + n) 2 + M + 3n] / 2 + 1, S = [(m ₁ + n ₁ ) ² + m ₁ + 3n ₁ ] / 2 + 1, r = (x ² + y ² ) ^1/2 , m ₁ is the upper limit of m, and n ₁ is n Is the upper limit of. The lighting device according to claim 12, further comprising a light source control device that controls the output of the first light emitting element independently of the output of the second light emitting element. Equipped with a wavelength conversion element
The lighting device according to claim 12 or 13, wherein a predetermined region of the wavelength conversion element corresponds to the illuminated region. The lighting device according to any one of claims 1 to 14.
An optical modulation device that generates image light by modulating the illumination light emitted from the lighting device according to image information.
A projector including a projection optical system for projecting the image light. The lighting device according to claim 9 or 12.
An optical modulation device that generates image light by modulating the illumination light emitted from the lighting device according to image information.
It is equipped with a projection optical system that projects the image light.
A projector in which the image forming region of the optical modulation device corresponds to the illuminated region. The lighting device according to claim 13 and
An optical modulation device that generates image light by modulating the illumination light from the lighting device according to image information.
It is equipped with a projection optical system that projects the image light.
The light source device further includes a third light emitting element that emits a third light bundle.
The photoforming optical system further includes a third lens surface on which the third light flux is incident.
The third lens surface has a third free curved surface represented by the formula (1).
With respect to the third free-form surface, the coefficient C _j ^{of the term x 2h} is different from the coefficient C _j of the term y ^2h.
The photoforming optical system is configured such that the third ray bundle illuminates the entire illuminated area.
The light source control device is configured to control the output of the third light emitting element independently of at least one of the output of the first light emitting element and the output of the second light emitting element. ,
A projector in which the image forming region of the optical modulation device corresponds to the illuminated region. The lighting device according to any one of claims 8, 11, or 14.
An optical modulation device that generates image light by modulating the illumination light from the wavelength conversion element according to image information.
A projector including a projection optical system for projecting the image light.

Images