JP2018132687A - Wavelength conversion element, light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength conversion element capable of adjusting a color of exiting light by a simple configuration.SOLUTION: The wavelength conversion element of the present invention includes: a phosphor member having a light-entering surface and a light-exiting surface, converting a part of excitation light in a first wavelength band into converted light including a second wavelength band, and exiting the rest of the excitation light and the converted light; and a wavelength selection member disposed on the light-exiting surface side of the phosphor member and having a wavelength separation characteristic between the first wavelength band and the second wavelength band. An area of an overlap region where the wavelength selection member and the light-exiting surface is overlapped is variable.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wavelength conversion element, a light source device, and a projector.

  As a light source device used for a projector, a light source device that irradiates a fluorescent material with excitation light emitted from a light emitting element such as a semiconductor laser and uses fluorescent light obtained from the fluorescent material has been proposed. For example, Patent Document 1 below discloses a light source device including a wavelength conversion member having a configuration in which two wavelength conversion layers having different emission spectra are stacked.

Japanese Patent Laying-Open No. 2015-5650

  In the light source device described in Patent Document 1, the thickness ratio of the two wavelength conversion layers varies depending on the location, and the color of light emitted from the wavelength conversion member is adjusted by changing the irradiation position of the excitation light. ing. However, in this configuration, the ratio of the thicknesses of the two wavelength conversion layers must be changed depending on the location, and it is difficult to manufacture the wavelength conversion member.

  One aspect of the present invention has been made to solve the above-described problems, and an object thereof is to provide a wavelength conversion element that can adjust the color of emitted light with a simple configuration. One aspect of the present invention is to provide a light source device including the above-described wavelength conversion element. One aspect of the present invention is to provide a projector including the light source device described above.

  In order to achieve the above object, a wavelength conversion element according to one aspect of the present invention has a light incident surface and a light exit surface, and a part of excitation light in the first wavelength band is converted into the second wavelength band. A fluorescent member that converts the converted light into the converted light, and emits the other part of the excitation light and the converted light, and is provided on the light emission surface side of the fluorescent member. A wavelength selection member having a wavelength separation characteristic between the wavelength band and the second wavelength band, and an area of an overlapping region where the wavelength selection member and the light exit surface overlap each other is variable.

  In the wavelength conversion element according to one aspect of the present invention, by changing the area of the overlapping region between the wavelength selection member and the light emission surface, the light amount of the component emitted through the wavelength selection member out of the total light amount of the emitted light. You can change the proportion of Thereby, the ratio of the light quantity of the 1st wavelength band component and the light quantity of the 2nd wavelength band component can be changed, and the color of emitted light can be adjusted. According to one aspect of the present invention, it is not necessary to stack a plurality of phosphor layers, and a wavelength conversion element that can adjust the color of emitted light with a simple configuration can be realized.

  In the wavelength conversion element according to one aspect of the present invention, the second wavelength band includes a green band, and the wavelength selection member reflects the light in the first wavelength band, and the light in the second wavelength band. It may have a wavelength separation characteristic that transmits light.

  In a general phosphor, excitation light is converted into converted light having a longer wavelength than the excitation light. Therefore, in one aspect of the present invention, when the second wavelength band includes a green band, a wavelength separation characteristic that reflects light in the first wavelength band and transmits light in the second wavelength band is used. The ratio of the light in the second wavelength band in the emitted light is higher than that in the case of using the wavelength separation characteristic that transmits the light in the first wavelength band and reflects the light in the second wavelength band. That is, since the ratio of green light having high visibility to the emitted light is high, it is possible to obtain emitted light that is felt bright by human eyes.

  The wavelength conversion element according to one aspect of the present invention may further include a first light reflecting member provided on a surface intersecting with the light emitting surface.

  According to this structure, it can suppress that excitation light and converted light leak from the surface which cross | intersects a light-projection surface by the 1st light reflection member. Thereby, light utilization efficiency can be improved.

  In the wavelength conversion element according to one aspect of the present invention, the wavelength selection member has a wavelength separation characteristic of reflecting the light of the first wavelength band and transmitting the light of the second wavelength band, and the light The incident surface may include a transmission region that transmits the excitation light and a reflection region that reflects the excitation light.

  According to this configuration, the component of the excitation light reflected by the wavelength selection member is further reflected by the reflection region of the light incident surface. Therefore, the excitation light can be reused.

  In the wavelength conversion element according to one aspect of the present invention, the light exit surface also serves as the light incident surface, and the wavelength selection member transmits the light in the first wavelength band, and the second wavelength. There may be further provided a second light reflecting member having a wavelength separation characteristic for reflecting the band light and provided on the opposite side of the light emitting surface of the phosphor member.

  According to this configuration, it is possible to realize a wavelength conversion element that makes light incident from the same side as the light exit surface, that is, a so-called reflection type wavelength conversion element.

  In the wavelength conversion element according to one aspect of the present invention, the excitation light may be blue light, and the converted light may include green light and red light.

  According to this configuration, it is possible to realize a wavelength conversion element capable of adjusting white balance.

  A light source device according to one aspect of the present invention includes the wavelength conversion element according to one aspect of the present invention, a light emitting element that emits the excitation light, and an area control device that controls an area of the overlapping region.

  According to this configuration, it is possible to realize a light source device that can easily adjust the color of the emitted light.

  A projector according to one aspect of the present invention includes a light source device according to one aspect of the present invention, a light modulation device that generates image light by modulating light from the light source device according to image information, and the image light. A projection optical system.

  According to this configuration, a projector with excellent color reproducibility can be realized.

It is a schematic block diagram of the projector of 1st Embodiment. It is sectional drawing of the wavelength conversion element of 1st Embodiment. It is a top view of a wavelength conversion element. It is a figure for demonstrating the effect | action of a wavelength conversion element. It is a figure for demonstrating the effect | action of a wavelength conversion element. It is a figure which shows an example of the wavelength separation characteristic of a wavelength selection member. It is a figure which shows an example of an optical sensor unit. It is a flowchart which shows the adjustment procedure of the color of illumination light. It is a figure which shows the wavelength separation characteristic of the wavelength selection member of 2nd Embodiment. It is a figure which shows the wavelength separation characteristic of the wavelength selection member of 3rd Embodiment. It is sectional drawing of the wavelength conversion element of 4th Embodiment. It is a schematic block diagram of the projector of 5th Embodiment. It is sectional drawing of the wavelength conversion element of 5th Embodiment. It is a figure which shows the other structural example of an optical sensor unit.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The projector according to the present embodiment is an example of a liquid crystal projector including a light source device including a semiconductor laser and a wavelength conversion element.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

  The projector according to the present embodiment is a projection type image display device that displays a color image on a screen (projected surface). The projector uses three light modulation devices corresponding to each color light of red light, green light, and blue light. The projector uses a semiconductor laser (laser diode) that can obtain light with high luminance and high output as a light emitting element of the light source device.

FIG. 1 is a schematic configuration diagram of a projector according to the present embodiment.
As shown in FIG. 1, the projector 1 includes a light source device 100, a color separation light guide optical system 200, a light modulation device 400R, a light modulation device 400G, a light modulation device 400B, a combining optical system 500, and a projection. And an optical system 600.
The light source device 100 of this embodiment corresponds to the light source device in the claims.

  The light source device 100 includes a light emitting element 10, a collimating optical system 70, a wavelength conversion element 20, an area control device 40, a pickup optical system 90, a homogenizer optical system 125, a polarization conversion element 140, and a superimposing lens 150. It is equipped with.

  The light emitting element 10, the collimating optical system 70, the wavelength conversion element 20, the pickup optical system 90, the homogenizer optical system 125, the polarization conversion element 140, and the superimposing lens 150 are disposed on the illumination optical axis 100ax.

The light emitting element 10 is composed of a semiconductor laser that emits excitation light LE. The light emitting element 10 emits blue excitation light LE in a first wavelength band having a peak wavelength of emission intensity of 445 nm, for example. The light emitting element 10 may be composed of one semiconductor laser or may be composed of a plurality of semiconductor lasers. The light emitting element 10 may emit excitation light having a peak wavelength of emission intensity other than 445 nm (for example, 460 nm).
The light emitting device 10 of the present embodiment corresponds to the light emitting device of the claims.

  The collimating optical system 70 includes a first lens 72 and a second lens 74. The collimating optical system 70 makes the light emitted from the light emitting element 10 substantially parallel. The 1st lens 72 and the 2nd lens 74 are comprised from the convex lens.

The wavelength conversion element 20 converts part of the excitation light LE into fluorescent light LY (converted light), and emits the other part of the excitation light LE and the fluorescent light LY. The fluorescent light LY is yellow light including green light and red light.
The wavelength conversion element 20 will be described in detail later.

  The area control device 40 controls the area of an overlapping region between a wavelength selection member 24 (to be described later) and a light emission surface 22b of the phosphor member 22. The area control device 40 includes a mirror glass 41, an afocal optical system 43, an optical sensor unit 46, an arithmetic processing device 47, a storage unit 48, and a drive device 49. The operation of the area control device 40 will be described in detail later.

  The pickup optical system 90 substantially collimates the fluorescent light LY emitted from the wavelength conversion element 20. The pickup optical system 90 includes a first pickup lens 92 and a second pickup lens 94. The first pickup lens 92 and the second pickup lens 94 are composed of convex lenses.

  The homogenizer optical system 125 includes a first lens array 120 and a second lens array 130. The first lens array 120 has a plurality of first microlenses 122 for dividing the light emitted from the pickup optical system 90 into a plurality of partial light beams. The plurality of first microlenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The second lens array 130 includes a plurality of second microlenses 132 corresponding to the plurality of first microlenses 122 of the first lens array 120. The second lens array 130, together with the superimposing lens 150, forms an image of each of the plurality of first microlenses 122 of the first lens array 120 in each of the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B. An image is formed in the vicinity of the region. The plurality of second microlenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

  The polarization conversion element 140 converts each partial light beam divided by the first lens array 120 into linearly polarized light. The polarization conversion element 140 includes a polarization separation layer, a reflection layer, and a retardation layer. The polarization separation layer transmits one linearly polarized light component of the polarized light components included in the light from the wavelength conversion element as it is and reflects the other linearly polarized light component in a direction perpendicular to the illumination optical axis 100ax. The reflective layer reflects the other linearly polarized light component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 100ax. The retardation layer converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component.

  The superimposing lens 150 collects the partial light beams from the polarization conversion element 140 and superimposes them on each other in the vicinity of the image forming regions of the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B. The first lens array 120, the second lens array 130, and the superimposing lens 150 constitute an integrator optical system that uniformizes the in-plane light intensity distribution of the light emitted from the wavelength conversion element 20.

  The color separation light guide optical system 200 separates the white illumination light LW into red light LR, green light LG, and blue light LB. The color separation light guide optical system 200 includes a first dichroic mirror 210, a second dichroic mirror 220, a first total reflection mirror 230, a second total reflection mirror 240, a third total reflection mirror 250, and a first relay. A lens 260 and a second relay lens 270 are provided.

  The first dichroic mirror 210 has a function of separating the illumination light LW emitted from the light source device 100 into red light LR and other light (green light LG and blue light LB). The first dichroic mirror 210 transmits the red light LR and reflects other light (green light LG and blue light LB). On the other hand, the second dichroic mirror 220 has a function of separating other light into green light LG and blue light LB. The second dichroic mirror 220 reflects the green light LG and transmits the blue light LB.

  The first total reflection mirror 230 is disposed in the optical path of the red light LR, and reflects the red light LR transmitted through the first dichroic mirror 210 toward the light modulation device 400R. The second total reflection mirror 240 and the third total reflection mirror 250 are arranged in the optical path of the blue light LB, and reflect the blue light LB transmitted through the second dichroic mirror 220 toward the light modulation device 400B. The green light LG is reflected by the second dichroic mirror 220 toward the light modulation device 400G.

  The first relay lens 260 and the second relay lens 270 are disposed on the light emission side of the second dichroic mirror 220 in the optical path of the blue light LB.

  The light modulation device 400R modulates the red light LR according to the image information to form image light corresponding to the red light LR. The light modulation device 400G modulates the green light LG according to image information, and forms image light corresponding to the green light LG. The light modulation device 400B modulates the blue light LB in accordance with the image information, and forms image light corresponding to the blue light LB.

  For example, a transmissive liquid crystal panel is used for the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B. In addition, polarizing plates (not shown) are disposed on the incident side and the emission side of the liquid crystal panel, respectively, so that only linearly polarized light in a specific direction is transmitted.

  A field lens 300R, a field lens 300G, and a field lens 300B are disposed on the incident side of the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B, respectively. The field lens 300R, the field lens 300G, and the field lens 300B collimate the red light LR, the green light LG, and the blue light LB incident on the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B, respectively.

  The combining optical system 500 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB when the image light from the light modulation device 400R, the light modulation device 400G, and the light modulation device 400B enters. Then, the combined image light is emitted toward the projection optical system 600. For the combining optical system 500, for example, a cross dichroic prism is used.

  The projection optical system 600 includes a projection lens group 6. The projection optical system 600 enlarges and projects the image light combined by the combining optical system 500 toward the screen SCR. Thereby, an enlarged color video (image) is displayed on the screen SCR.

Hereinafter, the configuration of the wavelength conversion element 20 will be described.
FIG. 2 is a cross-sectional view of the wavelength conversion element 20. FIG. 3 is a plan view of the wavelength conversion element 20 viewed from the direction of the illumination optical axis 100ax. 4A and 4B are diagrams for explaining the operation of the wavelength conversion element 20.
As shown in FIG. 2, the wavelength conversion element 20 includes a phosphor member 22, a wavelength selection member 24, and a reflection film 26 (first light reflection member).

  The phosphor member 22 has a light incident surface 22a and a light exit surface 22b. The excitation light LE in the first wavelength band enters the phosphor member 22 from the light incident surface 22a. The phosphor member 22 converts a part of the excitation light LE into a fluorescent light LY (converted light) in the second wavelength band, and emits light together with another part LE1 of the excitation light LE that has not been converted into the fluorescent light LY. Ejected from the surface 22b. In the present embodiment, the first wavelength band is a blue band, and the second wavelength band is a yellow band. Hereinafter, the other partial LE1 is referred to as an unconverted component LE1.

The phosphor member 22 is made of, for example, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a kind of YAG phosphor using Ce as an activator. The phosphor member 22 may have light scattering characteristics due to a large number of pores provided therein. Moreover, the form of the phosphor member 22 is not particularly limited, and may be, for example, a bulk shape or a thin film formed on a transparent substrate.

  The reflective film 26 is provided on the side surface 22c intersecting the light incident surface 22a and the light emitting surface 22b of the phosphor member 22. The reflective film 26 may be made of a metal film having a high reflectance such as aluminum or silver, or may be made of a dielectric multilayer film. The reflective film 26 has a characteristic of reflecting incident light regardless of the wavelength.

  The wavelength selecting member 24 is provided on the light emitting surface 22b side of the phosphor member 22 and slightly spaced from the light emitting surface 22b. The wavelength selection member 24 of the present embodiment is composed of a pair of plate members 241 having wavelength separation characteristics between a first wavelength band (blue band) and a second wavelength band (yellow band). The pair of plate members 241 is provided so that one surface of each plate member 241 faces the light emission surface 22 b of the phosphor member 22. In addition, each of the pair of plate members 241 is configured to move in a direction parallel to the light exit surface 22b (the direction of the arrow M) so as to be separated from or approach each other.

  Specifically, for example, the plate material 241 may be formed by forming a wavelength selective film made of a dielectric multilayer film on one surface of a light transmissive plate material, or may be colored glass.

  As shown in FIG. 3, when the pair of plate members 241 are moved in a direction approaching each other, when the wavelength conversion element 20 is viewed from the surface normal direction of the light emission surface 22 b, each plate member 241 constituting the wavelength selection member 24. Overlaps the light exit surface 22b. In the example shown in FIG. 3, there are two regions where each plate 241 overlaps with the light exit surface 22b, but these are collectively referred to as an overlap region K, and each plate 241 and the light exit surface 22b do not overlap. The region is referred to as an opening region H.

  As shown in FIG. 4A, when the pair of plate members 241 are brought close to each other until they come into contact with each other, the area of the overlapping region K is maximized and coincides with the area of the light emitting surface 22b. Hereinafter, this state is referred to as a fully closed state. On the other hand, as shown in FIG. 4B, when the pair of plate members 241 are separated to the maximum, each plate member 241 and the light emission surface 22b do not overlap each other, and the area of the overlapping region K becomes zero. Hereinafter, this state is referred to as a fully opened state. FIG. 2 shows a pair of plate members 241 in an intermediate state between the fully closed state and the fully open state. As described above, by separating or approaching the pair of plate members 241 from each other, the area of the overlapping region K is variable within a predetermined range (from 0 to an area equal to the area of the light emitting surface 22b). Yes.

FIG. 5 is a diagram illustrating an example of the wavelength separation characteristic of the wavelength selection member 24.
As shown in FIG. 5, the wavelength selection member 24 of the present embodiment reflects the light in the first wavelength band (blue band) and the second wavelength band (yellow band) including the green light LG and the red light LR. ).

  Therefore, as shown in FIG. 4A, when the wavelength selection member 24 is in the fully closed state, among the other part LE1 and the fluorescence light LY of the excitation light LE emitted from the light emission surface 22b of the phosphor member 22, The other part LE1 of the excitation light LE is reflected by the wavelength selection member 24, and the fluorescent light LY passes through the wavelength selection member 24. As a result, only the fluorescent light LY (yellow light) is emitted from the wavelength conversion element 20 through the wavelength selection member 24.

  4B, when the wavelength selection member 24 is in the fully open state, all of the unconverted component LE1 and fluorescent light LY emitted from the light emission surface 22b of the phosphor member 22 pass through the opening region H. And injected. That is, the ratio of yellow light in the light emitted from the wavelength conversion element 20 is the same as the ratio of yellow light in the light emitted from the phosphor member 22.

  As shown in FIG. 2, when the wavelength selection member 24 is in an intermediate state between the fully closed state and the fully open state, in the overlapping region K, the unconverted component LE1 is reflected by the wavelength selection member 24, and fluorescent light is emitted. LY passes through the wavelength selection member 24. On the other hand, in the opening region H, the unconverted component LE1 and the fluorescent light LY emitted from the light emitting surface 22b of the phosphor member 22 are emitted. As a result, the ratio of yellow light to the light emitted from the wavelength conversion element 20 is larger than the ratio of yellow light to the light emitted from the phosphor member 22.

  As described above, in the wavelength conversion element 20, the ratio of the blue light and the yellow light in the light emitted from the wavelength conversion element 20 is adjusted by moving the plate 241 to change the area of the overlapping region K. Can do. For example, if the ratio of yellow light to the light emitted from the phosphor member 22 is 70%, the ratio of yellow light to the light emitted from the wavelength conversion element 20 is changed by changing the area of the overlapping region K. It can be adjusted between 70% and 100% (in blue light, between 0% and 30%). In this manner, the wavelength conversion element 20 of the present embodiment can adjust the color of the emitted light.

Hereinafter, the configuration of the area control device 40 will be described.
As shown in FIG. 1, the mirror glass 41 is provided on the illumination optical axis 100ax between the pickup optical system 90 and the homogenizer optical system 125. The mirror glass 41 is disposed at an angle of 45 ° with respect to the illumination optical axis 100ax. As the mirror glass 41, a mirror glass having a small wavelength dependency of reflection characteristics and a high transmittance is used. That is, the mirror glass 41 reflects a small component of the incident illumination light LW and transmits the remaining many components regardless of the wavelength of the incident illumination light LW. The component reflected by the mirror glass 41 is used as light for monitoring the color of the illumination light LW. Hereinafter, this light is referred to as monitor light LM.

  The afocal optical system 43 is provided on the optical path of the monitor light LM between the mirror glass 41 and the optical sensor unit 46. The afocal optical system 43 reduces the beam diameter of the monitor light LM and emits the monitor light LM with the reduced beam diameter toward the optical sensor unit 46. The afocal optical system 43 includes a first afocal lens 44 made of a convex lens and a second afocal lens 45 made of a concave lens.

FIG. 6 is a diagram illustrating an example of the optical sensor unit 46.
The optical sensor unit 46 includes a dichroic mirror 461 and a plurality of power meters 462 and 463. The monitor light LM incident on the optical sensor unit 46 is separated into blue light LB1 and yellow light LY1 by the dichroic mirror 461. Each of the plurality of power meters 462 and 463 detects the intensity of each of the lights LB1 and LY1 separated by the dichroic mirror 461.

  The intensity of the blue light LB1 reflected by the dichroic mirror 461 is detected by the power meter 462. The intensity of the yellow light LY1 transmitted through the dichroic mirror 461 is detected by the power meter 463.

  The detection result of the intensity of each light LB1, LY1 detected by each power meter 462, 463 is sent to the arithmetic processing unit 47. The arithmetic processing device 47 calculates the light quantity ratio of each light based on these intensity detection results, and calculates the movement amount of the pair of plate members 241 of the wavelength selection member 24 corresponding to the light quantity ratio.

  The storage unit 48 stores a table indicating the relationship between the color of the illumination light LW and the light amount ratio.

  The driving device 49 moves the pair of plate members 241 of the wavelength selection member 24 so as to be separated from or approach each other based on the movement amount calculation result sent from the arithmetic processing device 47. In this way, the area of the overlapping region K is matched with the target value. A specific mechanism for moving the pair of plate members 241 is not particularly limited, and for example, a well-known slide mechanism including a guide rail and a motor can be used.

Hereinafter, a procedure for adjusting the color of the illumination light LW in the light source device 100 will be described.
FIG. 7 is a flowchart showing a procedure for adjusting the color of the illumination light LW.
First, a desired color of the illumination light LW is set (step S1). This step may be an operation in which a user of the projector 1 inputs a desired color mode among a plurality of color modes prepared in the projector 1 in advance.

  Next, the arithmetic processing unit 47 reads out the target value of the light amount ratio corresponding to the desired color inputted in step S1 from the table of the storage unit 48 (step S2). In the present embodiment, the ratio between the light amount of the blue light component and the light amount of the yellow light component in the illumination light LW is defined as the light amount ratio. For example, when a bluish white color is input as the desired color of the illumination light LW, for example, a light quantity ratio of 30/70 is read, and when a yellowish white color is input, 20/80 The desired color and the light amount ratio of the illumination light LW correspond to each other so that the light amount ratio is read out.

  Next, the optical sensor unit 46 detects the respective light amounts of the light of each wavelength band, that is, the blue light LB1 and the yellow light LY1, using the power meters 462 and 463 (step S3). Thereafter, the detection results of the light amounts of the blue light LB1 and the yellow light LY1 are sent to the arithmetic processing unit 47.

  Next, the arithmetic processing unit 47 calculates a light amount ratio based on the light amount detection result of light in each wavelength band (step S4).

  Next, the arithmetic processing unit 47 compares the calculated value of the light quantity ratio calculated in step S4 with the target value of the light quantity ratio read from the table in step S2, and whether the calculated value matches the target value. Is determined (step S5).

  If the calculated value does not coincide with the target value, the arithmetic processing unit 47 sends a signal to the driving device 49 to drive the wavelength selection member 24 and adjust the area of the overlapping region K (step) S6).

  As a specific example, assume that the calculated value of the light amount ratio is 25/75 and the target value of the light amount ratio is 30/70. Thus, when the calculated value is smaller than the target value, it is necessary to increase the amount of blue light in order to match the calculated value with the target value. Therefore, the arithmetic processing unit 47 drives the wavelength selection member 24 in a direction in which the pair of plate members 241 are separated from each other. On the contrary, when the calculated value is larger than the target value, it is necessary to reduce the amount of blue light, so the arithmetic processing unit 47 drives the wavelength selection member 24 in a direction in which the pair of plate members 241 approach each other.

  Thus, after driving the wavelength selection member 24 by a predetermined amount, steps S3 to S5 are repeated until the calculated value matches the target value, and the color of the illumination light LW is changed when the calculated value matches the target value. The adjustment is completed (step S7).

  In the wavelength conversion element 20 of the present embodiment, by changing the area of the overlapping region K between the wavelength selection member 24 and the light emission surface 22b of the phosphor member 22, the illumination light LW passes through the wavelength selection member 24. The proportion of the yellow light component emitted can be changed. Thereby, the ratio of the amount of blue light and the amount of yellow light contained in the illumination light LW can be changed, and the color of the illumination light LW can be adjusted. Thus, according to the present embodiment, the wavelength conversion element 20 capable of adjusting the color of the illumination light LW with a simple configuration is realized as compared with the conventional wavelength conversion element in which a plurality of phosphor layers are stacked. be able to.

  In particular, in the case of the present embodiment, the excitation light LE is blue light, the fluorescent light LY is yellow light including green light and red light, and the wavelength selection member 24 separates the blue light and yellow light. Therefore, the wavelength conversion element 20 that can adjust the white balance of the illumination light LW can be realized.

  In the present embodiment, since the wavelength selection member 24 has a wavelength separation characteristic that reflects the excitation light LE and transmits the fluorescence light LY, the amount of the fluorescence light LY increases when the area of the overlapping region K is increased. To change. Since the fluorescent light LY includes green light LG having high visibility to human eyes, bright emission light can be obtained by changing the fluorescent light LY in the direction of increasing the light amount as in the present embodiment. Is obtained.

  In the present embodiment, since the reflection film 26 is provided on the side surface 22c intersecting the light incident surface 22a and the light emission surface 22b of the phosphor member 22, the excitation light LE and the fluorescent light LY leak from the side surface 22c. Since this can be suppressed, the light utilization efficiency is increased.

  In addition, the light source device 100 of the present embodiment includes the wavelength conversion element 20, the light emitting element 10 that emits the excitation light LE, and the area control device 40 that controls the area of the overlapping region K. The color of the illumination light LW can be adjusted.

  In addition, since the projector according to the present embodiment includes the light source device 100 described above, the projector has excellent color reproducibility.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the projector, light source device, and wavelength conversion element of the second embodiment is the same as that of the first embodiment, and the wavelength separation characteristics of the wavelength selection member are different from those of the first embodiment. Therefore, descriptions of the projector, the light source device, and the wavelength conversion element are omitted, and only the wavelength selection member is described.
FIG. 8 is a diagram illustrating wavelength separation characteristics of the wavelength selection member according to the second embodiment.

  As shown in FIG. 8, in the present embodiment, light in the first wavelength band (blue band) is transmitted and light in the second wavelength band (yellow band) including the green light LG and the red light LR is reflected. A wavelength selection member having wavelength separation characteristics to be used is used.

  When this wavelength selection member is used, as the pair of plate materials are brought closer to each other and the overlapping region is increased, the ratio of blue light to the illumination light is increased and the ratio of yellow light is increased, contrary to the first embodiment. Get smaller. Further, as the pair of plate members are separated from each other and the overlapping region is reduced, the ratio of the blue light to the illumination light is reduced and the ratio of the yellow light is increased.

  Also in the present embodiment, the same effects as those of the first embodiment can be obtained in which a wavelength conversion element capable of adjusting the color of the emitted light can be realized with a simple configuration.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.
The basic configurations of the projector, the light source device, and the wavelength conversion element of the third embodiment are the same as those of the first embodiment, and the wavelength separation characteristics of the wavelength selection member are different from those of the first embodiment. Therefore, descriptions of the projector, the light source device, and the wavelength conversion element are omitted, and only the wavelength selection member is described.
FIG. 9 is a diagram illustrating wavelength separation characteristics of the wavelength selection member according to the third embodiment.

  As shown in FIG. 9, in this embodiment, a wavelength selection member having wavelength separation characteristics that reflects light in the first wavelength band (blue band) and transmits light in the second wavelength band (red band) is provided. It is used. In the present embodiment, the first wavelength band is a blue band, and the second wavelength band is a red band. The wavelength selection member has a wavelength separation characteristic that reflects light in a wavelength band other than the first wavelength band and the second wavelength band, that is, light in the green band together with light in the blue band.

  When this wavelength selection member is used, the ratio of blue light and green light in the emitted light decreases and the ratio of red light increases as the pair of plate materials are brought closer to each other and the overlapping region is increased. Further, as the pair of plate members are separated from each other and the overlapping region is reduced, the ratio of blue light and green light in the emitted light is increased, and the ratio of red light is decreased.

  Also in this embodiment, the same effects as those of the first and second embodiments can be obtained, such that a wavelength conversion element capable of adjusting the color of the emitted light with a simple configuration can be realized.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.
The basic configuration of the projector and the light source device of the fourth embodiment is the same as that of the first embodiment, and the configuration of the wavelength conversion element is different from that of the first embodiment. Therefore, descriptions of the projector and the light source device are omitted, and only the wavelength conversion element is described.
FIG. 10 is a cross-sectional view of the wavelength conversion element of the fourth embodiment.
10, the same code | symbol is attached | subjected to the same component as drawing used in 1st Embodiment, and detailed description is abbreviate | omitted.

  As shown in FIG. 10, the wavelength conversion element 50 of this embodiment includes a phosphor member 22, a wavelength selection member 24, a first reflection film 51 (first light reflection member), and a second reflection film. 52. The first reflective film 51 is the same member as the reflective film 26 of the first embodiment, and is provided on the side surface 22 c of the phosphor member 22.

  Similarly to the first embodiment, the wavelength selection member 24 reflects light in the first wavelength band (blue band) and emits light in the second wavelength band (yellow band) including the green light LG and the red light LR. It has a wavelength separation characteristic to be transmitted.

  The second reflective film 52 is provided on a part of the light incident surface 22 a of the phosphor member 22. Similar to the first reflective film 51, the second reflective film 52 may be composed of a metal film having a high reflectance such as aluminum or silver, or may be composed of a dielectric multilayer film. The second reflective film 52 only needs to have a characteristic of reflecting light in at least the first wavelength band (blue band), but may have a characteristic of reflecting light in all visible bands. .

As described above, since the second reflective film 52 is provided on a part of the light incident surface 22a of the phosphor member 22, in the region where the second reflective film 52 is not provided in the light incident surface 22a. The excitation light LE is transmitted, and the excitation light LE is reflected in the region where the second reflective film 52 is provided. That is, the light incident surface 22a includes a transmission region T that transmits the excitation light LE and a reflection region R that reflects the excitation light LE.
Other configurations of the wavelength conversion element 50 are the same as those in the first embodiment.

  Also in this embodiment, the same effects as those of the first to third embodiments can be obtained, such that a wavelength conversion element that can adjust the color of the emitted light with a simple configuration can be realized.

  In the wavelength conversion element 20 of the first embodiment, a part of the excitation light LE reflected by the wavelength selection member 24 and traveling toward the light incident surface 22a may be emitted from the light incident surface 22a. It was not used as optical LW. On the other hand, in the wavelength conversion element 50 of this embodiment, since the light incident surface 22a includes the transmission region T and the reflection region R, a part LE2 of the excitation light LE incident from the transmission region T has a wavelength of After being reflected by the selection member 24 and traveling toward the light incident surface 22a, the light is reflected by the second reflective film 52 in the reflective region R. The light LE2 travels again toward the light exit surface 22b and is used as the illumination light LW.

  In addition, when the second reflective film 52 has a characteristic of reflecting all visible band light, not only a part LE2 of the excitation light LE but also a component of the fluorescent light LY that travels toward the light incident surface 22a. Is also reflected by the reflection region R and used as illumination light. Thus, according to this embodiment, the wavelength conversion element 50 with high light utilization efficiency can be realized.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIGS. 11 and 12.
Among the projectors of the fifth embodiment, the configurations of the light source device and the wavelength conversion element are different from those of the first embodiment, and other configurations are common. Therefore, description of common parts is omitted, and only the light source device and the wavelength conversion element will be described.
FIG. 11 is a schematic configuration diagram of a projector according to the fifth embodiment. FIG. 12 is a cross-sectional view of the wavelength conversion element of the fifth embodiment.
In FIG. 11 and FIG. 12, the same code | symbol is attached | subjected to the same component as drawing used in 1st Embodiment, and detailed description is abbreviate | omitted.

  As shown in FIG. 12, in the projector 2 of the present embodiment, the light source device 101 includes a light emitting element 10, a collimating optical system 70, a wavelength conversion element 60, an area control device 40, a pickup optical system 90, and a position. A phase difference plate 81, a polarization separation element 82, a homogenizer optical system 125, a polarization conversion element 140, and a superimposing lens 150 are provided.

  The wavelength conversion element 20, the pickup optical system 90, the phase difference plate 81, the polarization separation element 82, the homogenizer optical system 125, the polarization conversion element 140, and the superimposing lens 150 are disposed on the illumination optical axis 100ax. The light emitting element 10 and the collimating optical system 70 are arranged on an optical axis 110ax orthogonal to the illumination optical axis 100ax. The wavelength conversion element 60 will be described in detail later.

  The polarization separation element 82 has polarization separation characteristics that reflects S-polarized light and transmits P-polarized light with respect to light in the first wavelength band (blue band). Further, the polarization separation element 82 has a wavelength separation characteristic that transmits light of the second wavelength band (yellow band) including the green light LG and the red light LR regardless of the polarization state. The polarization separation element 82 is disposed so as to form an angle of 45 ° with respect to each of the illumination optical axis 100ax and the optical axis 110ax.

  The phase difference plate 81 is composed of, for example, a quarter wavelength plate. The S-polarized excitation light LEs reflected by the polarization separation element 82 is converted into, for example, clockwise circularly polarized light by passing through the phase difference plate 81. The excitation light LEr that has passed through the phase difference plate 81 enters the pickup optical system 90.

  As shown in FIG. 12, the wavelength conversion element 60 of this embodiment includes a phosphor member 22, a wavelength selection member 64, a first reflection film 61 (first light reflection member), and a second reflection film. 62 (second light reflecting member). The first reflective film 61 is the same member as the reflective film 26 of the first embodiment, and is provided on the side surface 22 c of the phosphor member 22.

  The wavelength conversion element 60 of the present embodiment is a reflective wavelength conversion element. That is, the light exit surface 22ab of the wavelength conversion element 60 also serves as a light incident surface on which the excitation light LEr is incident.

  Similarly to the wavelength selection member of the second embodiment shown in FIG. 8, the wavelength selection member 64 transmits the light in the first wavelength band (blue band) and includes the second light including the green light LG and the red light LR. It has a wavelength separation characteristic that reflects light in the wavelength band (yellow band). In the case of this embodiment, since the excitation light LEr is incident from the side of the light exit surface 22ab on which the wavelength selection member 64 is provided, the wavelength selection member 64 has a wavelength separation characteristic that transmits light in the first wavelength band. If not, the excitation light LEr cannot enter through the overlapping region between the wavelength selection member 64 and the light exit surface 22ab. For example, if the pair of plate members 641 of the wavelength selection member 64 is in a fully closed state, the excitation light LEr cannot enter the phosphor member 22 at all, and the fluorescence light LY cannot be obtained.

The second reflective film 62 is provided on the entire surface of the phosphor member 22 opposite to the light exit surface 22ab. Similar to the first reflective film 61, the second reflective film 62 may be composed of a metal film having a high reflectance such as aluminum or silver, or may be composed of a dielectric multilayer film. The second reflective film 62 has a characteristic of reflecting all visible band light. As described above, since the second reflective film 62 is provided on the surface opposite to the light emitting surface 22ab, the other part of the excitation light LEr and the fluorescent light LY are reflected by the second reflective film 62. The light is emitted from the light exit surface 22ab.
Other configurations of the wavelength conversion element 60 are the same as those in the first embodiment.

  For example, the excitation light LEr incident as clockwise circularly polarized light is converted into counterclockwise circularly polarized light LEv when reflected by the second reflecting film 62, and is emitted from the light exit surface 22ab together with the fluorescent light LY. Thereafter, the counterclockwise circularly polarized light LEv that has passed through the pickup optical system 90 passes through the phase difference plate 81 again, and is converted into P-polarized blue light LEp. The blue light LEp passes through the polarization separation element 82 and proceeds toward the mirror glass 41.

  The mirror glass 41 constituting the area control device 40 is provided on the illumination optical axis 100ax between the polarization separation element 82 and the homogenizer optical system 125. Other configurations of the area control device 40 are the same as those in the first embodiment.

  In the wavelength conversion element 60 of the present embodiment, as the pair of plate members 641 of the wavelength selection member 64 are brought closer to each other and the overlapping region is increased, the ratio of blue light to the illumination light LW increases and the ratio of yellow light decreases. Become. Further, as the pair of plate members 641 are separated from each other and the overlapping region is reduced, the ratio of blue light to the illumination light LW is reduced and the ratio of yellow light is increased.

  Thus, the same effects as those of the first to fourth embodiments can be obtained, such that the wavelength conversion element 60 that can adjust the color of the emitted light with a simple configuration can be realized.

  According to the configuration of the present embodiment, it is possible to realize a wavelength conversion element 60 that makes light incident from the same side as the light exit surface 22ab, that is, a so-called reflection type wavelength conversion element.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the light source device of the above embodiment, the optical sensor unit 46 shown in FIG. 6 is used for the area control device, but instead of this configuration, the optical sensor unit 146 shown in FIG. 13 may be used.

  As shown in FIG. 13, the optical sensor unit 146 includes a color sensor 147 including a color CCD, a color CMOS image sensor, and the like. The color sensor 147 detects a light amount ratio for each of a plurality of wavelength ranges obtained by dividing the visible band.

  In the first embodiment, as a procedure for adjusting the color of the illumination light, the projector user inputs the desired color of the illumination light, and the area control device sets the input desired color to the target value. As an example of adjusting the area of the overlapping region, instead of this example, for example, when the color of the illumination light changes due to the change of the light emitting element over time, the sensor detects the change in color and controls the area. The apparatus may be configured to adjust the area of the overlapping region using the color of the illumination light before aging as a target value.

  Moreover, although the example of the wavelength selection member which consists of a pair of board | plate material which approaches or spaces apart from each other was given in the said embodiment, the structure of the wavelength selection member which makes the area of an overlapping region variable is not limited to this. For example, a wavelength selection member made of a plate material having a wedge-shaped opening and made movable may be used.

  In addition, the number, shape, material, arrangement, and the like of each component constituting the wavelength conversion element and the light source device can be appropriately changed. In the above embodiment, a projector including three light modulation devices has been exemplified. However, the present invention can also be applied to a projector that displays a color image with one light modulation device. Furthermore, the light modulation device is not limited to the above-described liquid crystal panel, and for example, a digital mirror device can be used.

In addition, the shape, number, arrangement, material, and the like of various components of the projector are not limited to the above-described embodiment, and can be changed as appropriate.
Moreover, although the example which mounted the light source device by this invention in the projector was shown in the said embodiment, it is not restricted to this. The light source device according to the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

  DESCRIPTION OF SYMBOLS 1, 2 ... Projector, 10 ... Light emitting element, 20, 50, 60 ... Wavelength conversion element, 22 ... Phosphor member, 22a ... Light incident surface, 22b, 22ab ... Light emission surface, 22c ... Side surface (crossing light emission surface) Surface, 24, 64 ... wavelength selection member, 26 ... reflection film (first light reflection member) 40 ... area control device, 51, 61 ... first reflection film (first light reflection member), 62 ... Second reflective film (second light reflecting member), 100, 101 ... light source device, 400R, 400G, 400B ... light modulation device, 600 ... projection optical system, R ... reflection region, T ... transmission region, K ... overlap Region, LE ... excitation light, LY ... fluorescence light (converted light).

Claims (8)

A light incident surface and a light exit surface, and a part of the excitation light in the first wavelength band is converted into converted light including light in the second wavelength band, and the other part of the excitation light and the A phosphor member that emits converted light; and
A wavelength selection member provided on the light emission surface side of the phosphor member, and having a wavelength separation characteristic between the first wavelength band and the second wavelength band;
The wavelength conversion element, wherein an area of an overlapping region where the wavelength selection member and the light exit surface overlap is variable. The second wavelength band includes a green band;
2. The wavelength conversion element according to claim 1, wherein the wavelength selection member has a wavelength separation characteristic that reflects light in the first wavelength band and transmits light in the second wavelength band.   The wavelength conversion element according to claim 1, further comprising a first light reflecting member provided on a surface intersecting with the light emitting surface. The wavelength selection member has a wavelength separation characteristic that reflects light in the first wavelength band and transmits light in the second wavelength band,
The wavelength conversion element according to claim 3, wherein the light incident surface includes a transmission region that transmits the excitation light and a reflection region that reflects the excitation light. The light exit surface also serves as the light incident surface,
The wavelength selection member has a wavelength separation characteristic that transmits light in the first wavelength band and reflects light in the second wavelength band,
The wavelength conversion element according to claim 1, further comprising a second light reflecting member provided on a side opposite to the light emitting surface of the phosphor member. The excitation light is blue light;
The wavelength conversion element according to any one of claims 1 to 5, wherein the converted light includes green light and red light. The wavelength conversion element according to any one of claims 1 to 6,
A light emitting element that emits the excitation light;
A light source device comprising: an area control device that controls an area of the overlapping region. The light source device according to claim 7;
A light modulation device that generates image light by modulating light from the light source device according to image information;
A projection optical system that projects the image light.

Images