JP2015228312A - Optical device and image display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device achieving projection of a brighter image by adjusting a color balance.SOLUTION: The optical device includes a phosphor 122 that converts a part of a luminous flux from a LD (laser diode) into converted light having a wavelength different from that of the luminous flux from the LD and that exits the converted light and unconverted light having the same wavelength as that of the luminous flux from the LD. The optical device further includes: a photosensor that measures a light quantity of the unconverted light and a light quantity of the converted light; and adjustment means for adjusting efficiency of a fluorescent light circular plate 120 for converting the luminous flux from the LD into converted light on the basis of a measurement result by the photosensor. The fluorescent light circular plate 120 has different efficiencies of converting a luminous flux from the LD into converted light depending on a position thereof; and the adjustment means comprises a movement actuator that adjusts a position where the luminous flux from the LD is incident to the fluorescent light circular plate 120.

Description

  The present invention relates to an optical device and an image display device such as a projector using the same. In particular, the present invention relates to a light source device using a solid light source such as an LD (laser diode) light source and an image display device such as a projection display device using the same.

  In recent years, a projector that displays a color image using a phosphor that converts blue light from an LD light source into yellow light has been developed.

  A projector using an LD light source and a phosphor may lose RGB color balance as compared with a projector using a conventional mercury lamp as a light source. This is because, for example, the temperature in the projector rises due to the environment in which the projector is used or the passage of time such as long-term use, resulting in a decrease in LD output and a decrease in phosphor conversion efficiency. As a result, the luminance of yellow light emitted from the phosphor may be reduced, and the RGB color balance may be lost. The conversion efficiency is the efficiency with which the phosphor converts blue light that is excitation light from the LD light source into yellow light that is fluorescence light.

  Therefore, as shown in Patent Document 1, there has been proposed a projector capable of adjusting the color balance and suppressing the deterioration of the color balance over time.

  In Patent Document 1, for example, the amount of blue light from the LD light source and the amount of yellow light from the phosphor are measured every minute, and based on the ratio between the two measurement results, the light emission amount of the LD light source and the liquid crystal panel Control the modulation amount. Specifically, the intensity of the fluorescent light is made constant by increasing the output of the LD light source, and the increased intensity of the blue light is adjusted by modulation of the liquid crystal panel. Thus, a technique for suppressing the deterioration of color balance over time has been disclosed.

JP 2011-145368 A

  In general, when adjusting the color balance of a projected image by controlling the modulation amount of the liquid crystal panel, the maximum modulation amount of the light modulation device for other colors is used with reference to the maximum modulation amount of the liquid crystal panel with the least amount of light. Decrease the modulation amount.

  As an example, in the case of a projected image that is yellowish because there is little blue light, instead of increasing blue light, the maximum modulation amount of the light modulator for green light and the light modulator for red light is increased. Reduce the color balance. On the other hand, when there is a lot of blue light and it is tinged with blue, color balance adjustment is performed by reducing the maximum modulation amount of the blue light modulation device.

  However, if the maximum modulation amount of the light modulation device of another color is reduced with reference to the maximum modulation amount of the liquid crystal panel with the least amount of light, the color balance can be adjusted, but the projected image becomes dark. End up.

  That is, in the configuration disclosed in Patent Document 1 described above, if the color balance is adjusted by controlling the modulation amount of the liquid crystal panel, the brightness of the projected image may be impaired.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical device and an image display device capable of adjusting color balance and realizing a brighter image projection.

In order to achieve the above object, the optical device of the present invention comprises:
A wavelength conversion element that converts a part of the light beam from the light source into converted light having a wavelength different from that of the light beam from the light source, and emits the converted light and non-converted light having the same wavelength as the light beam from the light source; ,
Measuring means for measuring the amount of the non-converted light and the amount of the converted light;
Adjusting means for adjusting the efficiency with which the wavelength conversion element converts the light beam from the light source into the converted light based on the measurement result by the measuring means;
The wavelength conversion element differs in efficiency in converting the light beam from the light source into the converted light by the wavelength conversion element,
The adjusting means is a place adjusting means for adjusting a place where a light beam from the light source is incident on the wavelength conversion element.
It is characterized by that.

  According to the present invention, it is possible to provide an optical device and an image display device capable of adjusting color balance and realizing a brighter image projection.

The figure explaining the structure of the projection type display apparatus using the light source device which concerns on each embodiment of this invention. The figure explaining the structure of the light source device which concerns on 1st embodiment of this invention. The figure explaining the structure of the fluorescent screen which concerns on 1st embodiment of this invention. The figure explaining the thickness dependence of the fluorescence conversion efficiency of the fluorescent substance which concerns on embodiment of this invention The figure which shows the light emission spectrum from the light source device at the time of changing the irradiation place of excitation light in the fluorescent substance area | region from which thickness differs concerning embodiment of this invention Flowchart of control for adjusting color balance according to an embodiment of the present invention The figure explaining the structure of the light source device which concerns on 2nd embodiment of this invention. The figure explaining the structure of the fluorescent disc which concerns on 2nd embodiment of this invention. The figure explaining the structure of the fluorescent disc which concerns on 3rd embodiment of this invention. The figure which shows the light emission spectrum from the light source device at the time of changing excitation light irradiation place in the fluorescent substance area | region which has arranged the thinning pattern which concerns on embodiment of this invention

  Preferred embodiments of the present invention will be illustratively described below with reference to the drawings. However, the shapes of components described in this embodiment and their relative arrangements should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions. In other words, the shape of the component parts and the like are not stipulated to limit the scope of the present invention to the following embodiments.

[Description of Configuration of Projection Display Device]
First, the configuration of a projection display device 1000 that is an image display device using the light source device 1 shown in each embodiment of the present invention will be described with reference to FIG.

  The display device (projection display device) 1000 includes a light source device 1, an illumination optical system 200, a color separation / synthesis system 300, a light modulation panel driver 3, and a projection lens 4. Thereby, the display apparatus 1000 can project an image on the screen 5.

  Each embodiment of the present invention described later can be applied to the light source device 1.

  The illumination optical system 200 guides the light flux from the light source device 1 to a color separation / synthesis system 300 described later.

  The light beam emitted from the light source device 1 is split by the first fly-eye lens 21 and the second fly-eye lens 22. Further, the light beam emitted from the light source device 1 is converted into S-polarized light by the polarization conversion element 23. Here, the S-polarized light is a light beam linearly polarized in the direction perpendicular to the paper surface.

  The light beam emitted from the polarization conversion element 23 is condensed by the condenser lens unit 24 so as to illuminate a liquid crystal panel 2 (2R, 2G, 2B) described later in a superimposed manner. In the embodiment of the present invention, the condenser lens unit 24 includes three condenser lenses 24A, 24B, and 24C.

  The color separation / combination system 300 decomposes the light flux from the illumination optical system 200 for each wavelength, synthesizes image light to be displayed on the screen, and guides the image light to the projection lens 4 described later.

  The dichroic mirror 30 has characteristics of reflecting red light (R light) and blue light (B light) and transmitting green light (G light). The R light and B light reflected by the dichroic mirror 30 enter the wavelength selective phase plate 34. The wavelength-selective phase plate 34 has a characteristic that gives a phase difference of half a wavelength to the B light and does not give a phase difference to the R light. Therefore, the B light incident on the wavelength selective phase plate 34 becomes P-polarized light, and the R light becomes S-polarized light and enters a PBS (polarization beam splitter) 33 described later. The P-polarized light is a light beam linearly polarized in the horizontal direction on the paper.

  Since the PBS 33 has characteristics of transmitting P-polarized light and reflecting S-polarized light, the B light passes through the PBS 33 and enters the liquid crystal panel 2B, and the R light is reflected by the PBS 33 and enters the liquid crystal panel 2R. .

  On the other hand, the G light transmitted through the dichroic mirror 30 passes through the dummy glass 36 for correcting the optical path length and enters the PBS 31. Since the PBS 31 has characteristics of transmitting P-polarized light and reflecting S-polarized light, the G light is reflected by the PBS 31 and enters the liquid crystal panel 2G.

  The above is the description until the light flux from the light source device 1 enters the liquid crystal panel 2. Next, a description will be given of the process until the image light is emitted from the liquid crystal panel 2 and the image is projected onto the light diffusion screen 5. Here, the image light is a light beam for displaying an image to be projected on the light diffusion screen 5. Note that the light diffusion surfaces of the liquid crystal panels 2B, 2G, and 2R and the light diffusion screen 5 are optically conjugate with each other by the projection lens 4. For this reason, an image according to the video signal is displayed on the light diffusion screen 5.

  The light beam incident on the liquid crystal panel (light modulation element) 2 is given a phase difference so as to become a light beam having a desired polarization direction according to the modulation state of the pixels arranged on the liquid crystal panel 2. Among the light beams to which the phase difference is given, the component having the same polarization direction as the light beam from the light source device 1 returns to the light source device 1 side and is excluded from the image light. On the other hand, a component having a 90-degree polarization direction different from that of the light beam from the light source device 1 is guided to the combining prism 32.

  Here, the light modulation performed by the liquid crystal panel is controlled by a signal from the light modulation panel driver 3. The light modulation panel driver 3 converts an external video input signal (not shown) into a light modulation panel drive signal. Drive signals from the light modulation panel driver 3 are independently supplied to the liquid crystal panel 2R for R light, the liquid crystal panel 2G for G light, and the liquid crystal panel 2B for B light, each of which is composed of a reflective liquid crystal element via a dotted line in the figure. Sent.

  When the R light from the light source device 1 is converted from S-polarized light to P-polarized light by the R light liquid crystal panel 2R, the R light of the P-polarized light passes through the PBS 33 and enters the wavelength selective phase plate 35. To do. The wavelength-selective phase plate 35 has a characteristic that does not give a phase difference to the B light and gives a phase difference corresponding to a half wavelength to the R light. For this reason, the R light transmitted through the wavelength selective phase plate 35 enters the combining prism 32 as S-polarized light.

  When the B light from the light source device 1 is converted from P-polarized light to S-polarized light by the B light liquid crystal panel 2 </ b> B, the S-polarized light is reflected by the PBS 33 and passes through the wavelength selective phase plate 35. Since the wavelength selective phase plate 35 does not give a phase difference to the B light, the B light of S-polarized light enters the combining prism 32.

  When the G light from the device 1 is converted from S-polarized light to P-polarized light by the G light liquid crystal panel 2G, the P-polarized light passes through the PBS 31 and enters the dummy glass 37 for correcting the optical path length. To do. The G light transmitted through the dummy glass 37 enters the combining prism 32.

  Since the combining prism 32 has characteristics of transmitting P-polarized light and reflecting S-polarized light, when the above modulation is performed, the G light is transmitted through the combining prism 32, and the B light and the R light are transmitted by the combining prism 32. It is reflected and guided to the projection lens 4. As a result, a color image can be projected onto the screen 5 via the projection lens 4. The function of the photosensor (measurement means) 6 is as described later.

[First embodiment]
FIG. 2 is a diagram for explaining the configuration of the light source device shown in the first embodiment of the present invention, and FIG. 3 is a diagram for explaining the configuration of the fluorescent plate 110 used in the light source device shown in the first embodiment of the present invention. is there.

  First, the configuration of the light source device shown in the first embodiment of the present invention and the principle of emitting white light will be described with reference to FIG. In this embodiment, the optical device converts a part of the light beam from the LD 100 into converted light having a wavelength different from that of the light beam from the LD 100, converted light, and non-converted light having the same wavelength as the light beam from the LD 100; Is provided with a fluorescent plate 110 that emits light. Furthermore, the optical device measures the light quantity of the non-converted light and the light quantity of the converted light, and the efficiency with which the fluorescent plate 110 converts the light flux from the LD 100 into the converted light based on the measurement result by the photo sensor 6. Adjusting means for adjusting. In the optical device, the fluorescent plate 110 has different efficiency for converting the light beam from the LD 100 into converted light depending on the location, and the adjusting means is a moving actuator 140 that adjusts the location where the light beam from the LD 100 is incident on the fluorescent plate 110. It is characterized by. In this embodiment, the light source device includes the LD 100 and the optical device described above.

  The LD 100 (100a, 100b, 100c, 100d, 100e) is a laser diode that oscillates B light and has an oscillation wavelength of 448 nm. The light beam from the LD 100 is guided to the reflection mirror 106 after being compressed by the condensing lens 101 that is a convex lens and the condensing lens 102 that is a concave lens.

  The reflection mirror 106 is formed of a dichroic mirror having a characteristic that the central portion transmits B light and reflects yellow light, and the outer periphery of the reflection mirror 106 is formed of a mirror that reflects light regardless of the wavelength. Therefore, the light beam from the LD 100 passes through the central portion of the reflection mirror 106, is further condensed by the condenser lenses 103, 104, and 105 and is guided to the fluorescent plate 110. Note that the B light is condensed at almost one point on the surface of the fluorescent plate 110.

Part of the B light collected on the fluorescent plate (fluorescent member) 110 that is a wavelength conversion element is converted into fluorescent light that is yellow light (Y light) by the phosphor 112 on the surface of the fluorescent plate. The phosphor 112 is a yellow phosphor that emits fluorescence of Y light when excited by B light. Specifically, the phosphor 112 is a YAG-based phosphor (Y, Gd) ₃ (Al, Ga) ₅ O _12. : Made of Ce. The yellow phosphor may be made of a phosphor other than those described above. The phosphor 112 has a structure in which a particulate fluorescent material that diffuses light is dispersed in a binder, and emitted fluorescence is emitted in all directions. On the other hand, the B light that has not been absorbed is diffused by the fluorescent particles and reflected by the substrate 111. That is, in this embodiment, the non-converted light is a part of the B light from the LD 100, and the converted light is Y light that is fluorescent light converted by the phosphor 112.

  The reflected B light and the Y light emitted as fluorescent light are incident on the condenser lenses 103, 104, and 105, and are guided to the reflecting mirror 106 as substantially parallel light with a thick light beam.

  Since the reflection mirror 106 has the above-described configuration, the B light returns to the LD 100 side in the light flux incident on the central portion of the reflection mirror 106 from the fluorescent plate 110. On the other hand, the Y light is reflected by the dichroic mirror at the center of the reflecting mirror 106 and guided to the illumination optical system in the direction of the arrow shown in FIG.

  A light beam incident on the outer periphery from the central portion of the reflecting mirror 106 from the fluorescent plate 110 is reflected by the reflecting mirror 106 and guided to the illumination optical system in the direction of the arrow shown in FIG.

  As described above, the light source device shown in the present embodiment synthesizes the B light that is non-converted light and the Y light that is fluorescent light to emit white light.

  Next, the configuration of the fluorescent plate 110 and the principle of adjusting the efficiency with which the fluorescent plate 110 converts the light flux from the LD 100 into fluorescent light will be described with reference to FIG.

  As shown in FIG. 3A, the fluorescent plate 110 has a structure in which a phosphor 112 is attached and formed on a substrate 111 whose surface is processed into a mirror surface. In this embodiment, the substrate 111 is made of aluminum. The cross-sectional shape of the fluorescent plate 110 is formed such that the thickness of the phosphor 112 gradually changes from about 0 μm to about 200 μm, as shown in FIG.

  As described above, the tapered shape can be formed by using a screen printing method when the phosphor 112 is applied to the substrate 111. The screen printing method is a method in which a screen having a transmission hole through which a coating liquid can pass is placed on a substrate, and the coating liquid is applied onto the substrate through the screen. In order to make the cross-sectional shape of the phosphor 112 have a tapered shape as shown in FIG. 3B, the density of the transmission holes is increased in a portion where the phosphor 112 is thick. On the other hand, the thin portion of the phosphor 112 can have a tapered cross-sectional shape by reducing the density of the transmission holes.

  Here, the relationship between the thickness of the phosphor and the conversion efficiency for converting B light into Y light is shown in FIG. As shown in FIG. 4, the conversion efficiency has a characteristic of gradually decreasing as the thickness decreases with a peak at 200 μm. Further, the conversion efficiency is also reduced when the thickness is greater than 200 μm. This is because the portion where the phosphor is thick contains a lot of fluorescent material, so that much of the B light can be converted into Y light. In other words, the portion where the phosphor is thick has higher conversion efficiency than the thin portion. However, if the phosphor is too thick, Y light that cannot be emitted from the phosphor 112 increases. The Y light that cannot be emitted from the phosphor 112 is absorbed, for example, as heat, so that the conversion efficiency decreases.

  Thus, the efficiency with which the fluorescent plate 110 converts the luminous flux from the LD 100 into fluorescent light differs depending on the location. In other words, the efficiency with which the fluorescent plate 110 converts the luminous flux from the LD 100 into fluorescent light changes along the predetermined direction 201. In other words, the efficiency with which the fluorescent plate 110 converts the luminous flux from the LD 100 into fluorescent light changes from a predetermined location of the fluorescent plate 110 toward the predetermined direction 201. Note that the predetermined place mentioned here may be any side or vertex of the fluorescent plate 110 as long as the fluorescent plate 110 is rectangular as in the present embodiment.

  Next, the principle of adjusting the place where the light beam from the LD 100 enters the fluorescent plate 110 will be described.

  As shown in FIG. 2, the fluorescent plate 110 can be moved in the vertical direction (predetermined direction) in FIG. 2 by a moving actuator (location adjusting means) 140. For this reason, the condensing place 200 of the B light on the phosphor 112 can be adjusted in the direction indicated by the predetermined direction 201 by the moving actuator 140.

  As shown by the broken line in FIG. 5, when the condensing place 200 moves to the thin side of the phosphor, the conversion efficiency decreases, the B light component increases, and the Y light component decreases. The balance can be adjusted.

  On the other hand, when the condensing place 200 moves to the thicker side of the phosphor, the white light color balance is changed such that the B light component decreases and the Y light component increases as shown by the one-dot chain line in FIG.

  Next, a color balance adjustment method in the embodiment of the present invention will be described with reference to FIG.

  First, in the B light emission step S1, the liquid crystal panel 2B displays 100%, the liquid crystal panel 2G displays 0%, and the liquid crystal panel 2R displays 0%. Here, the liquid crystal panel 2B performing 100% display indicates that the liquid crystal panel 2B modulates the B light so that most of the B light incident on the liquid crystal panel 2B is guided to the projection lens 4. On the contrary, when the liquid crystal panels 2G and 2R perform 0% display, the G light incident on the liquid crystal panel 2G and the R light incident on the liquid crystal panel 2R are prevented from being led to the projection lens 4. 2G modulates G light, and the liquid crystal panel 2R modulates R light.

  After the B light emission step S1, the B light amount A is measured in a B light amount measurement step (first measurement step) S2. That is, the B light amount measurement step S2 is a first measurement step for measuring the light amount of the light flux from the LD 100. Note that the B light quantity measurement step S2 may not be a measurement step for directly measuring the light quantity of the light beam immediately after being emitted from the LD 100. For example, the light quantity of a light beam having the same wavelength as that of the light beam from the LD 100 may be measured using a photo sensor 6 described later.

  A photo sensor (measuring means) 6 measures the amount of light. The photosensor 6 measures the amount of leaked light that has been reflected by the composite prism 32, although it should have been transmitted through the composite prism 32 and guided toward the projection lens 4.

  Following the B light quantity measurement step S2, in the Y light emission step S3, the liquid crystal panel 2B displays 0%, the liquid crystal panel 2G displays 100%, and the liquid crystal panel 2R displays 100%.

  After the Y light emission step S3, the Y light amount B is measured in a Y light amount measurement step (second measurement step) S4. That is, the Y light quantity measurement step S4 is a second measurement step for measuring the light quantity of the converted light in the luminous flux from the fluorescent plate 110. The Y light quantity measurement step S4 may not be a measurement step for directly measuring the Y light immediately after being emitted from the light source device 1000. For example, the amount of R light and G light included in the Y light emitted from the light source device 1000 may be measured using the photo sensor 6 described above. That is, the light amount B may be the sum of the light amounts of R light and G light included in the Y light emitted from the light source device 1000.

  After the Y light quantity measurement step S4, a light quantity ratio C which is a ratio between the light quantity A and the light quantity B is calculated in a light quantity ratio calculation step (calculation step) S5. After the light quantity ratio calculation step S5, light quantity ratio comparison steps (comparison steps) S6 and S8 for comparing the light quantity ratio C, which is the calculation result of the light quantity ratio calculation step S5, with a predetermined value D are performed.

  As a result of the light quantity ratio comparison steps S6 and S8, when the light quantity ratio C is larger than a predetermined value D, an efficiency adjustment step for increasing the efficiency of converting the light beam from the LD 100 into fluorescent light having a wavelength different from that of the light beam from the LD 100. (Adjustment step) S7 is performed.

  In the efficiency adjustment step S7, in order to reduce the light amount ratio C and approach the predetermined value D, the conversion efficiency into fluorescent light is increased.

  That is, in order to increase the light quantity B of Y light and reduce the light quantity ratio C, the moving actuator 140 shown in FIG. 2 moves the condensing place 200 shown in FIG. The place where the phosphor 112 is thick contains more fluorescent material than the thin place. Therefore, if the B light is incident on the place where the phosphor 112 is thick, more Y light can be emitted. The ratio C can be reduced to approach the predetermined value D.

  On the other hand, when the light amount ratio C is smaller than the predetermined value D as a result of the light amount ratio comparison steps S6 and S8, the efficiency for converting the light beam from the LD 100 into fluorescent light having a wavelength different from that of the light beam from the LD 100 is reduced. An efficiency adjustment step (adjustment step) S9 is performed.

  In the efficiency adjustment step S9, in order to increase the light amount ratio C and approach the predetermined value D, the conversion efficiency to fluorescent light is reduced.

  That is, in order to increase the light quantity A of B light and increase the light quantity ratio C, the moving actuator 140 shown in FIG. 2 moves the condensing place 200 shown in FIG. The place where the phosphor 112 is thin has less fluorescent material than the thick place. Therefore, if the B light is incident on the place where the phosphor 112 is thin, the B light which is not converted into Y light increases, so the light amount ratio C is increased. , It can be close to the predetermined ratio D. After the efficiency adjustment steps S7 and S9 are executed, the process returns to the B light quantity measurement step S2.

  When the light quantity ratio C is equal to the predetermined value D, the conversion efficiency to fluorescent light is maintained.

  That is, the above-described control adjusts the efficiency with which the phosphor 112 converts the light beam from the LD 100 into fluorescent light based on the measurement result by the photosensor 6.

  By performing such control, an image with a white color balance can be displayed on the screen 5. Such control does not need to reduce the maximum modulation amount of the light modulation device of another color with reference to the maximum modulation amount of the liquid crystal panel with the least amount of light. For this reason, compared with the method of adjusting the modulation amount of the liquid crystal panel to adjust the color balance, the loss of the light amount of the projected image can be reduced, and a brighter image can be realized.

  The above-described operation is performed according to the usage time of the apparatus, and it is preferable to operate every 10 minutes or less. Further, the above-described operation may be performed not only when the apparatus is in use but every 10 minutes or less, but also when the apparatus is started and stopped. Further, the above-described operation may not be performed while the apparatus is in use, but may be performed only when the apparatus is started and stopped. Furthermore, the above-described operation may be performed only when the apparatus is activated.

  By performing the above-described operation when the apparatus is activated, it is possible to perform adjustment according to the use environment of the apparatus and project an image with a good color balance. Further, by performing the above-described operation when the apparatus is stopped, adjustment at the time of activation is unnecessary, and the apparatus can be put into a usable state more quickly.

  Thus, the light source device shown in the present embodiment adjusts the place 200 where the blue light from the LD 100 that is the excitation light is condensed on the fluorescent plate 110 by the moving actuator 140. As a result, the color balance of the white light emitted from the light source device can be changed.

[Second Embodiment]
FIG. 7 is a diagram illustrating the configuration of the light source device shown in the second embodiment of the present invention. FIG. 8 is a diagram illustrating the configuration of the fluorescent disk 120 in this embodiment.

  The difference between the present embodiment and the first embodiment described above is that the fluorescent disk 120 is used instead of the fluorescent plate 110 as a wavelength conversion element or fluorescent member, and a rotation motor (drive unit) for rotating the fluorescent disk 120. 150 is further provided.

  The principle of emitting white light by combining the blue light from the LD 100 and the yellow light from the fluorescent disk 120 other than the use of the fluorescent disk 120 instead of the fluorescent plate 110 is the same as in the first embodiment. It is.

  As shown in FIG. 8A, the fluorescent disk (fluorescent member) 120 has a structure in which the phosphor 122 is attached in the circumferential direction of the substrate 121 formed in the same manner as the substrate 111 except for the shape. Yes.

  The cross-sectional shape of the phosphor 122 is formed so that the thickness of the phosphor 122 gradually changes from about 200 μm to about 0 μm in the radial direction of the disk as shown in FIG. 8B. Such a shape can be formed by a screen printing method as in the first embodiment.

  Similar to the first embodiment described above, the condensing place 200 can be moved in the direction indicated by the direction 201 by the moving actuator 140. When the condensing place 200 moves to the outside of the fluorescent disc 120, the luminous flux from the LD 100 is incident on the thin side of the phosphor 122, and the fluorescence conversion efficiency decreases. As a result, the spectrum of the light emitted from the light source device has a distribution indicated by the dotted line in FIG. That is, when the condensing place 200 moves to the outside of the fluorescent disk 120, the color balance of white light is changed such that the blue light component increases and the yellow light component decreases.

  On the other hand, when the condensing place 200 moves to the inside of the fluorescent disk 120, the luminous flux from the LD 100 is incident on the thicker side of the phosphor 122, and the fluorescence conversion efficiency is improved. As a result, the spectrum of the light emitted from the light source device has a distribution indicated by a one-dot chain line in FIG. That is, when the condensing place 200 moves to the inside of the fluorescent disk 120, the color balance of white light is changed such that the blue light component decreases and the yellow light component increases.

  As described above, the efficiency of the fluorescent disk 120 for converting the light beam from the LD 100 into fluorescent light differs depending on the location. In other words, in the fluorescent disk 120, the efficiency with which the fluorescent disk 120 converts the light flux from the LD 100 into fluorescent light changes along the predetermined direction 201. In other words, the efficiency with which the fluorescent disk 120 converts the luminous flux from the LD 100 into fluorescent light changes from a predetermined location of the fluorescent plate 120 toward the predetermined direction 201. Note that the predetermined place mentioned here may be one point on the center or outer periphery of the fluorescent disk 120 as long as the fluorescent disk 120 is circular as in the present embodiment, for example. Further, when the predetermined location is the center of the fluorescent disk 120, the conversion efficiency may change from the center of the fluorescent disk 120 along the radial direction.

  The control method for adjusting the color balance is the same as in the first embodiment.

  As described above, in the light source device shown in this embodiment, the moving actuator 140 changes the place 200 where the blue light from the LD 100 that is the excitation light is condensed on the fluorescent disk 120. As a result, the color balance of the white light emitted from the light source device can be changed. Therefore, it is possible to provide a light source device capable of adjusting the color balance and realizing a brighter image projection.

[Third embodiment]
FIG. 6 is a diagram for explaining the configuration of the light source device shown in the third embodiment of the present invention.

  The difference between the present embodiment and the second embodiment described above is that a phosphor 123 having a shape different from that of the phosphor 122 is provided on the substrate 121.

  FIG. 6 (A) shows a front view of the fluorescent disk 120 shown in this embodiment as viewed in the direction of the rotation axis. The phosphors 123 are attached in a thinned pattern, and the thinning ratio is formed so as to increase in the radial direction of the disk. As shown in FIG. 9B, in this embodiment, the phosphor 123 does not need to be tapered, and is configured to have a uniform thickness in the radial direction of the fluorescent disk 120. Specifically, the phosphor 123 is applied with a thickness of about 200 μm, which provides the maximum fluorescence conversion efficiency.

  In other words, in the fluorescent disk 120, a region where the phosphor 123 is provided is a fluorescent region 400, and a region where the phosphor 123 is not provided is a non-fluorescent region 401. Further, a circle that is concentric with the fluorescent disk 120 and has a radius R1 (first radius) is defined as a first circle. At this time, the ratio of the fluorescent region 400 to the non-fluorescent region 401 on the circumference of the first circle is a radius R2 (second radius) longer than the radius R1, and the fluorescent region 400 on the circumference of the second circle. And the ratio of the non-fluorescent region 401 is different.

  In other words, on the circumference of a predetermined circle that is concentric with the fluorescent disk 120 and has a predetermined radius, the area of the region 203 where the light flux from the LD 100 illuminates the phosphor 123 increases by a predetermined radius. As it gets smaller, it gets smaller or bigger. In the present embodiment, as shown in FIG. 9C, the fluorescent disk 120 is formed such that the area of the illumination region 203 gradually decreases as the area of the illumination disk 203 approaches the outer periphery.

  In other words, the fluorescent disk 120 is formed such that the thinning ratio increases as the radial direction of the fluorescent disk 120 increases.

  The phosphor 123 having such a shape can be formed by using the above-described screen printing method and providing a restriction such as masking so that the fluorescent material is not applied to the non-fluorescent region 401.

  Similar to the second embodiment described above, the condensing place 200 can be moved in the direction indicated by the direction 201 by the moving actuator 140. When the condensing place 200 moves to the outside of the fluorescent disk 120, the time during which the light beam from the LD 100 strikes the phosphor 123 is shortened, and the fluorescence conversion efficiency is lowered. As a result, the spectrum of the light emitted from the light source device has a distribution indicated by the dotted line in FIG. That is, when the condensing place 200 moves to the outside of the fluorescent disk 120, the color balance of white light is changed such that the blue light component increases and the yellow light component decreases.

  On the other hand, when the condensing place 200 moves to the inside of the fluorescent disk 120, the time during which the light beam from the LD 100 strikes the phosphor 123 becomes longer, so that the fluorescence conversion efficiency is improved. As a result, the spectrum of the light emitted from the light source device has a distribution indicated by a one-dot chain line in FIG. That is, when the condensing place 200 moves to the inside of the fluorescent disk 120, the color balance of white light is changed such that the blue light component decreases and the yellow light component increases.

  The control method for adjusting the color balance is the same as in the first embodiment.

  As described above, in the light source device shown in this embodiment, the moving actuator 140 changes the place 200 where the blue light from the LD 100 that is the excitation light is condensed on the fluorescent disk 120. As a result, the color balance of the white light emitted from the light source device can be changed. Therefore, it is possible to provide a light source device capable of adjusting the color balance and realizing a brighter image projection.

[Other Embodiments]
In the above-described embodiment, the blue light from the LD 100 that is the excitation light and the yellow light emitted from the phosphor are measured. Instead of measuring the yellow light from the phosphor, the G light or the R light is measured. And you can substitute it.

  In the above-described embodiment, the configuration in which the photosensor 6 is disposed in the vicinity of the combining prism 32 is illustrated, but the present invention is not limited to this. Instead of the photo sensor 6, for example, a configuration including a color sensor between the first fly-eye lens 21 and the second fly-eye lens 22 may be used. Further, a color sensor is disposed between the first fly-eye lens 21 and the second fly-eye lens 22 when the projection display device is activated. And the structure etc. which move a color sensor from between the 1st fly eye lens 21 and the 2nd fly eye lens 22 after predetermined time progress from starting may be sufficient.

  In the above-described embodiments, the configuration in which the phosphor is applied on the aluminum substrate is illustrated, but the present invention is not limited to this. As long as the color balance can be adjusted and a brighter image can be projected, for example, a configuration in which a phosphor is coated on a resin transparent substrate may be used.

  Further, in the above-described embodiment, the configuration including the projection lens is exemplified as the configuration of the projection display device that can mount the light source device shown in the embodiment of the present invention. However, the present invention is not limited to this. If it is a projection type display apparatus, the structure using a detachable projection lens may be used, for example.

  In the above-described embodiment, the configuration of the light source device using the LD light source that emits blue light is exemplified, but the present invention is not limited to this. For example, a blue LED light source may be used as long as the light source emits light in a blue wavelength band.

  In the above-described embodiment, the configuration of the light source device having no light source that emits blue light other than the LD light source is exemplified, but the present invention is not limited to this. For example, a configuration in which a blue LED light source is added in addition to the LD light source may be used.

  In the above-described embodiment, the configuration in which the dichroic mirror that transmits blue light and reflects yellow light is provided in the central portion and the mirror is provided in the outer peripheral portion is illustrated, but the present invention is not limited thereto. . The central portion may be a dichroic mirror that reflects blue light and reflects yellow light, and may have a configuration in which a phosphor is arranged in a direction in which blue light is reflected. Further, the dichroic mirror may be arranged not at the central portion but at a location shifted from the center of the reflecting mirror.

  Further, in the above-described embodiment, the configuration in which the fluorescent member is moved by the moving actuator to adjust the condensing place of the light beam from the LD light source is exemplified, but the present invention is not limited to this. For example, a configuration in which an LD light source is moved may be used as long as the color balance can be adjusted and a brighter image can be projected.

6 Photosensor (Measuring means)
120 Fluorescent disc (wavelength conversion element)
140 Moving actuator (place adjustment means)

Claims (10)

A wavelength conversion element that converts a part of the light beam from the light source into converted light having a wavelength different from that of the light beam from the light source, and emits the converted light and non-converted light having the same wavelength as the light beam from the light source; ,
Measuring means for measuring the amount of the non-converted light and the amount of the converted light;
Adjusting means for adjusting the efficiency with which the wavelength conversion element converts the light beam from the light source into the converted light based on the measurement result by the measuring means;
The wavelength conversion element differs in efficiency in converting the light beam from the light source into the converted light by the wavelength conversion element,
The adjusting means is a place adjusting means for adjusting a place where a light beam from the light source is incident on the wavelength conversion element.
An optical device. The wavelength conversion element changes the efficiency with which the wavelength conversion element converts a light beam from the light source into the converted light along a predetermined direction,
The location adjusting means can adjust the location where the light beam from the light source is incident on the wavelength conversion element in the predetermined direction.
The optical apparatus according to claim 1. The wavelength conversion element is a fluorescent member comprising a substrate and a phosphor provided on the substrate,
The optical apparatus according to claim 2, wherein the phosphor becomes thicker or thinner as it goes from the center of the fluorescent member toward the predetermined direction. The wavelength conversion element is a fluorescent member comprising a substrate and a phosphor provided on the substrate,
The optical apparatus according to claim 2, wherein the density of the phosphor increases or decreases from the center of the fluorescent member toward the predetermined direction. The wavelength conversion element is a fluorescent member comprising a substrate and a phosphor provided on the substrate,
Of the fluorescent member, when the region provided with the phosphor is a fluorescent region, and the region not provided with the phosphor is a non-fluorescent region,
The ratio of the fluorescent region to the non-fluorescent region on the circumference of the first circle that is concentric with the substrate and is the first radius is:
The ratio of the fluorescent region and the non-fluorescent region in the circumference of a second circle that is concentric with the substrate and is a second radius that is longer than the first radius is different from the ratio of the fluorescent region and the non-fluorescent region.
The optical apparatus according to claim 2. The substrate is a disc;
The phosphor is formed along the circumferential direction of the disc,
A drive unit for rotating the disk in the circumferential direction;
The optical device according to claim 3, wherein the optical device is an optical device. The light source is a laser diode that emits blue light,
The phosphor converts a part of the light flux from the laser diode into yellow light having a wavelength different from that of the light flux from the laser diode, and the yellow light and blue light having the same wavelength as the light flux from the laser diode; , Inject,
The optical apparatus according to claim 1, wherein the optical apparatus is an optical device. The measuring means is a photo sensor,
The photosensor measures the first light amount and the second light amount when the light amount of the non-converted light is a first light amount and the light amount of the converted light is a second light amount,
Calculating means for calculating a ratio of the first light quantity and the second light quantity;
Comparing means for comparing the calculation result by the calculating means with a predetermined value,
The adjustment means increases the efficiency when the calculation result is larger than the predetermined value as a result of the comparison means, and lowers the efficiency when the calculation result is smaller than the predetermined value. If the result is equal to the predetermined value, maintain the efficiency.
The optical device according to claim 1, wherein the optical device is an optical device. A light source device comprising: a light source; and the optical device according to any one of claims 1 to 8.
A light modulation element;
A color separation and synthesis system for decomposing a light beam from the light source device and guiding the light beam to the light modulation element, and combining the light beam from the light modulation element;
An illumination optical system that guides a light beam from the light source device to the color separation / synthesis system,
An image display device characterized by that. A first measurement step for measuring the amount of light flux from the light source;
A part of the light beam from the light source is converted into converted light having a wavelength different from that of the light beam from the light source, and the converted light and non-converted light having the same wavelength as the light beam from the light source are emitted. A second measuring step of measuring the light quantity of the converted light among the light fluxes from the wavelength conversion elements having different conversion efficiencies for converting the light flux from the light source into the converted light;
A calculation step for calculating a ratio between a first light amount that is a measurement result of the first measurement step and a second light amount that is a measurement result of the second measurement step;
A comparison step of comparing the calculation result of the calculation step with a predetermined value;
As a result of the comparison step, when the calculation result is larger than the predetermined value, the efficiency of converting the light beam from the light source into converted light having a wavelength different from that of the light beam from the light source is increased, and the calculation result is the predetermined value. An adjustment step that reduces the efficiency if it is smaller than a value, and maintains the efficiency if the calculation result is equal to the predetermined value,
After execution of the adjustment step, the process returns to the first measurement step again.
A color balance adjustment method characterized by that.

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