JP2012073489A - Light source unit and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify an optical layout in a projector including a light source unit capable of generating the three primary colors of light by using a blue light source as an excitation light source.SOLUTION: The projector comprises: the light source unit 60; a display element 51; a light source side optical system 170 that emits light from the light source unit 60 to the display element 51; a projection side optical system 221 that emits projection light generated by the display element 51, toward a screen; and projector control means that controls the light source unit 60 and display element 51. The light source unit 60 includes: an excitation light source 71 that emits light of a specific wavelength band range; and a light emitting plate 101 including a fluorescent light emitting part that uses the surface as a reflecting face and in which a phosphor layer laid for emitting light of the specific wavelength band range by using light emitted from the excitation light source 71 as excitation light is provided, and a diffusion part for diffusing light emitted from the excitation light source 71. A prism 141 is disposed between the light emitting plate 101 and excitation light source 71.

Description

  The present invention relates to a light source unit and a projector including the light source unit.

  2. Description of the Related Art Today, data projectors are widely used as image projection apparatuses that project a screen of a personal computer, a video image, an image based on image data stored in a memory card or the like onto a screen. In such projectors, many developments and proposals have been made in recent years using light emitting diodes (LEDs), laser light emitters, organic ELs, or phosphors as light emitting elements used as light sources.

  For example, in Japanese Patent Application Laid-Open No. 2004-341105 (Patent Document 1), red, green, and blue phosphor layers are juxtaposed on the surface of a light-emitting plate made of a translucent disc, and the back surface of the light-emitting plate is arranged. Proposal of a light source device that generates light source light in the red, green, and blue wavelength bands by arranging ultraviolet transmissive and visible light dichroic filters and irradiating the phosphor layer with ultraviolet light from the back side of the light emitting plate. Yes. According to the invention of Patent Document 1, light sources of red, green, and blue wavelength bands can be generated. However, when an existing phosphor is used, it is difficult to make the output of three colors uniform. When this light source device is used for a projector, it is difficult to project an image with high color reproducibility and high luminance.

  Therefore, the applicant of the present application described in the previous application (Japanese Patent Application No. 2009-155434: unpublished), a red phosphor layer that emits red wavelength band light using the emitted light from the blue laser emitter as excitation light, and a blue laser. A light emitting wheel in which a green phosphor layer that emits green wavelength band light by using light emitted from a light emitter as excitation light and a diffuse transmission plate that diffuses and transmits light emitted from a blue laser light emitter are arranged in parallel in the circumferential direction. A light source device is proposed. In this proposal, a red phosphor layer and a green phosphor layer are laid on the reflecting surface, and red and green wavelength band light is emitted from the incident surface side of the light emitting wheel, and blue wavelength band light is emitted from the back surface side of the light emitting wheel. It is configured to inject. By adopting a structure in which the fluorescent light in the red and green wavelength bands is extracted from the incident surface side in this way, the reflecting surface provided on the surface of the light emitting wheel is combined with the fluorescent light directly emitted from the incident surface of the excitation light. Since the reflected fluorescent light can also be extracted from the incident surface, all the fluorescent light emitted from the phosphor in all directions can be extracted from the same surface, and the utilization efficiency of the fluorescent light can be increased.

JP 2004-341105 A

  In the above-mentioned proposal by the applicant of the present application, since the excitation light is blue wavelength band light, it is necessary to arrange a dichroic mirror that transmits blue and reflects red and green between the blue laser emitter and the emission wheel. . In the optical layout using this dichroic mirror, the red and green wavelength band light is emitted from the light emitting wheel to the excitation light source side, and the blue wavelength band light is transmitted through the light emitting wheel and is opposite to the red and green wavelength band light. Therefore, the light source light in the blue wavelength band needs to be converged on the display element through an optical path different from that of the red and green wavelength band lights. Therefore, in order to match the optical axes of the light of each wavelength band, at least one other dichroic mirror that transmits blue and reflects red and green, or reflects blue and transmits red and green is disposed. It was necessary for the three colors of light to have the same traveling direction in the same optical axis. Therefore, according to the above-mentioned proposal by the present applicant, the optical layout becomes complicated, and there is a limit to the reduction in size and thickness of the projector.

  The present invention has been made in view of such problems of the prior art. In a light source unit capable of generating three primary colors of light using a blue light source as an excitation light source and a blue wavelength band light generation source, It is an object of the present invention to provide a light source unit that achieves simplification and miniaturization of the optical layout by using the prism, and a projector that is further miniaturized and thinned by providing the light source unit.

  The light source unit of the present invention includes an excitation light source that emits light of a predetermined wavelength band, and a fluorescent layer in which a surface is used as a reflection surface and a phosphor layer that emits light of a predetermined wavelength band using the light emitted from the excitation light source as excitation light. A light emitting plate having a light emitting portion and a diffusing portion for diffusing light emitted from the excitation light source, and disposed between the light emitting plate and the excitation light source, adjusts the optical axis and totally reflects light. A prism formed by combining a first prism having a total reflection surface and a second prism that adjusts the optical axis and transmits light through an air layer, and includes the fluorescent light-emitting portion and the diffusing portion of the light-emitting plate. It has a drive means which makes it move alternately on the optical path of the excitation light through a prism sequentially.

  Further, in the light source unit of the present invention, the prism is arranged such that the second prism is located on the excitation light source side and the first prism is located on the light emitting plate side, and the emitted light from the excitation light source Is incident on and transmitted through the second prism, then enters the first prism through the air layer, further passes through the first prism and is irradiated onto the light-emitting plate, and light emitted from the light-emitting plate is The light is incident on the first prism, is reflected at the boundary surface between the first prism and the air layer, and is emitted to the outside.

  In the light source unit of the present invention, the prism is arranged such that the first prism is located on the excitation light source side and the second prism is located on the light emitting plate side, and Emission light is incident on the first prism, is reflected at the boundary surface between the first prism and the air layer, and is applied to the light emitting plate. The emitted light from the light emitting plate is emitted from the first prism and The second prism may be transmitted through the second prism and emitted to the outside.

  Furthermore, in the light source unit of the present invention, the excitation light source is a semiconductor light source that emits blue wavelength band light, and the light emitting plate has a red phosphor layer that receives the excitation light and emits light in a red wavelength band. A red fluorescent light emitting part, a green fluorescent light emitting part having a green phosphor layer that receives the excitation light and emits light in a green wavelength band, the diffusion part that diffuses the excitation light and emits blue wavelength band light, Is a light-emitting wheel arranged side by side in the circumferential direction.

  In the light source unit of the present invention, the excitation light source is a blue laser emitter.

  In the light source unit of the present invention, the red fluorescent light emitting unit and the green fluorescent light emitting unit have red wavelength band light and green wavelength band light on the side opposite to the surface irradiated with the excitation light of the light emitting plate. A dichroic mirror that reflects blue light and transmits blue wavelength band light is disposed, and a reflection mirror that reflects red, green, and blue wavelength band light is disposed in the diffusing section.

  The projector according to the present invention includes any one of the light source units described above, a display element, a light source side optical system that emits light emitted from the light source unit to the display element, and projection light generated by the display element. And a projector control means for controlling the light source unit and the display element.

  According to the present invention, in a light source unit capable of generating the three primary colors of light using a blue light source as an excitation light source and a blue wavelength band light source, the optical layout is simplified by using a plurality of prisms. It is possible to provide a light source unit that can be easily reduced, and a projector that is further reduced in size and thickness by including the light source unit.

1 is an external perspective view showing a projector according to an embodiment of the invention. It is a figure which shows the functional block of the said projector. It is a schematic plan view showing the internal structure with the upper cover of the projector removed. It is the front view and sectional drawing of the light-emitting plate which concern on the Example of this invention. It is a schematic diagram which shows sectional drawing and the optical path of the said light-emitting plate. It is a figure which shows the optical layout which concerns on the other Example in the projector of this invention. It is a figure which shows the optical layout which concerns on the other Example in the projector of this invention. It is a figure which shows another optical layout in the projector of this invention. It is a figure which shows the optical layout which concerns on the different Example in the projector of this invention.

  Hereinafter, modes for carrying out the present invention will be described. The projector 1 according to the present invention includes a light source unit 60, a display element 51, a light source side optical system 170 that emits light emitted from the light source unit 60 to the display element 51, and projection light generated by the display element 51 on a screen. And a projector control means for controlling the light source unit 60 and the display element 51.

  The light source unit 60 is a fluorescent light emission having an excitation light source 71 that emits light of a predetermined wavelength band, and phosphor layers 111 and 112 that emit light of a predetermined wavelength band using the light emitted from the excitation light source 71 as excitation light on a reflection surface. And a light emitting plate 101 on which a diffusing unit 104 that diffuses light emitted from the excitation light source 71 is formed. A TIR prism (Total Internal Reflection Prism) 141 or an RTIR prism (Reverse Total Internal Reflection Prism) 141R is arranged between the light emitting plate 101 and the excitation light source 71.

  The TIR prism 141 and the RTIR prism 141R include an air layer including a first prism 142 having a total reflection surface that adjusts the optical axis and totally reflects light, and a second prism 143 that adjusts the optical axis and transmits light. Combined via 144. In the case of the TIR prism 141, the light emitted from the excitation light source 71 enters the first prism 142, is totally reflected at the boundary surface between the first prism 142 and the air layer 144, and is applied to the light emitting plate 101. The light emitted from the light emitting plate 101 enters the first prism 142, passes through the first prism 142, passes through the second prism 143 while adjusting the optical axis, and is emitted to the light source side optical system 170. In the case of the RTIR prism 141R, the light emitted from the excitation light source 71 enters the second prism 143, passes through while adjusting the optical axis, enters the first prism 142 via the air layer 144, and further passes through the first prism 142. The light emitted from the light-emitting plate 101 is transmitted through the light-emitting plate 101, and the light emitted from the light-emitting plate 101 enters the first prism 142 and is totally reflected at the boundary surface between the first prism 142 and the air layer 144. The light is emitted to the light source side optical system 170.

  Further, the excitation light source 71 is a blue laser emitter as a semiconductor light source that emits light in the blue wavelength band, and the light-emitting plate 101 has a red phosphor layer 111 that receives the excitation light and emits light in the red wavelength band. A fluorescent light emitting unit 102, a green fluorescent light emitting unit 103 having a green phosphor layer 112 that receives excitation light and emits light in a green wavelength band, a diffusion unit 104 that diffuses excitation light and emits blue wavelength band light, Is a light emitting wheel arranged side by side in the circumferential direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of the projector 1. In this embodiment, left and right in the projector 1 indicate the left and right direction with respect to the projection direction, and front and rear indicate the projection direction of the projector 1 and the front and rear direction with respect to the traveling direction of the light beam.

  As shown in FIG. 1, the projector 1 is a hand-held small projector 1 having a substantially rectangular parallelepiped shape, and is configured to cover an inside with an upper case 5 and a lower case 6. The front plate 12 formed by fitting the upper case 5 and the lower case 6 positioned in front of the projector housing has a lens barrel 225 disposed substantially at the center and an intake hole 18 in the vicinity of the right plate 15. Is formed.

  Further, a key / indicator portion 37 is provided on the upper plate 11 formed by the upper case 5 of the projector housing. The key / indicator portion 37 has a power switch key and a power indicator for notifying whether the power is on or off. There are arranged keys and indicators such as a projection switch key for switching projection on and off, an overheat indicator for notifying when a light source unit, a display element, a control circuit or the like is overheated. Furthermore, the back plate 13 and the right plate 15 formed by fitting the upper case 5 and the lower case 6 located at the rear or side of the projector housing have a USB terminal, a power adapter plug, a memory card insertion slot, etc. Various terminals are provided.

  Next, the projector control means of the projector 1 will be described using the functional block diagram of FIG. The projector control means includes a control unit 38, an input / output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, and the like. The control unit 38 controls the operation of each circuit in the projector 1, and includes a CPU as an arithmetic unit, a ROM that stores operation programs such as various settings in a fixed manner, and a RAM that is used as a work memory. It is comprised by.

  Then, the image signal of various standards input from the input / output connector unit 21 by the projector control means is in a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB). After being converted so as to be unified into an image signal, it is output to the display encoder 24. The display encoder 24 develops and stores the input image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display drive unit 26.

  The display drive unit 26 functions as display element control means, and drives the display element 51, which is a spatial light modulation element (SOM), at an appropriate frame rate corresponding to the image signal output from the display encoder 24. The light beam emitted from the light source unit 60 is irradiated onto the display element 51 through the light source side optical system, thereby forming a light image with the reflected light of the display element 51, and a projection side optical system to be described later The image is projected and displayed on a screen (not shown). The movable lens group 235 of the projection side optical system is driven by the lens motor 45 for zoom adjustment and focus adjustment.

  The image compression / decompression unit 31 reads the image data recorded on the memory card 32 at the time of reproduction, decompresses individual image data constituting a series of moving images in units of one frame, and outputs the image data to the image conversion unit 23. Through the display encoder 24 and based on the image data stored in the memory card 32, a process for enabling display of a moving image or the like is performed.

  Then, an operation signal from the key / indicator unit 37 provided in the upper case 5 of the housing is directly sent to the control unit 38. Note that an audio processing unit 47 is connected to the control unit 38 via a system bus (SB). The sound processing unit 47 includes a sound source circuit such as a PCM sound source, converts the sound data into analog in the projection mode and the reproduction mode, and drives the speaker 48 to emit loud sounds.

  The control unit 38 controls a light source control circuit 41 as a light source control means. The light source control circuit 41 controls an excitation light irradiation device (to be described later) and a wheel motor that rotates a light emission wheel so that light source light of a predetermined wavelength band required at the time of image generation is emitted from the light source unit 60. Further, the control unit 38 causes the cooling fan drive control circuit 43 to perform temperature detection using a plurality of temperature sensors provided in the light source unit 60 and the like, and controls the rotation speed of the cooling fan from the result of the temperature detection.

  Further, the projector control means includes an illuminance sensor 42 as illuminance measurement means for measuring the illuminance of light emitted from the light source unit 60. Then, the control unit 38 adjusts the voltage applied to each light source of the light source unit 60 based on the information regarding the output of each wavelength band light transmitted from the illuminance sensor 42, and maintains the luminance balance at the beginning of product shipment. .

  Next, the internal structure of the projector 1 will be described. FIG. 3 is a schematic plan view showing the internal structure of the projector 1. As shown in FIG. 3, the projector 1 includes a light source unit 60 at the center, and a lens barrel 225 with a projection-side optical system 221 provided on the left side of the light source unit 60. The lens barrel 225 and the left side plate A battery 55 is provided between 14 and 14. In addition, the projector 1 includes a display element 51 such as a DMD disposed in parallel with the left side plate 14 in the vicinity of the battery 55 between the lens barrel 225 and the back plate 13. Further, the projector 1 includes a main control circuit board 241 below the light source unit 60, and a power control circuit board 242 between the lens barrel 225 and the battery 55.

  In addition, the projector 1 includes a light source side optical system 170 that irradiates the display element 51 with light emitted from the light source unit 60 between the light source unit 60 and the lens barrel 225 and the back plate 13. Further, between the light source unit 60 and the right side plate 15, the power connector 80, a heat sink 190 for cooling internal devices, and heat generated by an excitation light source 71 described later are guided to the heat sink 190 in order from the back plate 13 side. A heat pipe 130 and a cooling fan 261 are provided.

  The light source unit 60 is reflected by the excitation light irradiation device 70 disposed in the vicinity of the front plate 12, the TIR prism 141 disposed on the optical path of the light beam emitted from the excitation light irradiation device 70, and the TIR prism 141. A light emitting wheel as the light emitting plate 101 disposed on the optical path of the emitted light from the excitation light irradiation device 70 and a wheel motor 107 as a driving means for rotating the light emitting wheel are provided. Further, between the light emitting plate 101 and the TIR prism 141, a condenser lens 110 that collects the light emitted from the excitation light irradiation device 70 and the light emitted from the light emitting plate 101 is disposed. The condensing lens 110 is formed by combining a plurality of lenses so as to generate one condensing lens.

  The excitation light irradiation device 70 includes two excitation light sources 71 and two collimator lenses 73 arranged on the optical axis of each excitation light source 71. The excitation light source 71 is a blue laser light emitter as a semiconductor light source, and emits a laser beam in a blue wavelength band toward the light emitting plate 101. Further, the excitation light source 71 is in contact with the heat pipe 130 via the substrate for the excitation light source 71, and is cooled by the heat sink 190 via the heat pipe 130. The collimator lens 73 converts the light emitted from the excitation light source 71 into parallel light bundles and emits the light toward the TIR prism 141.

  As shown in FIG. 4, the light emitting wheel as the light emitting plate 101 includes a red fluorescent light emitting unit 102 provided with a red phosphor layer 111 that receives light emitted from the excitation light irradiation device 70 and emits light in a red wavelength band, A green fluorescent light emitting unit 103 provided with a green phosphor layer 112 that receives light emitted from the excitation light irradiation device 70 and emits light in the green wavelength band, and a diffusion plate 105 that diffuses the light emitted from the excitation light irradiation device 70 A diffusion unit 104 that is laid and emits blue wavelength band light is arranged in parallel in the circumferential direction.

  The light emitting plate 101 in the red fluorescent light emitting unit 102 and the green fluorescent light emitting unit 103 includes a dichroic mirror 108 that transmits blue wavelength band light and reflects green and red wavelength band light, and includes a red phosphor layer 111 and Of the fluorescent light emitted from the green phosphor layer 112 in all directions, the fluorescent light emitted toward the light emitting plate 101 is reflected to the incident surface side, and the phosphors of the red phosphor layer 111 and the green phosphor layer 112 are reflected. Excitation light that is blue wavelength band light that has passed through each of the phosphor layers 111 and 112 without being involved in excitation is transmitted. As shown in FIG. 5A, the surface of the light-emitting plate 101 in the diffusing portion 104 is made into a mirror-like reflective surface 109 by silver vapor deposition or the like, and fine irregularities are formed on the surface of the reflective surface by sandblasting or the like. Yes. Further, the diffusion plate 105 is bonded to the surface of the light emitting plate 101 with an adhesive 106, and this adhesive 106 serves as a spacer, so that an air layer is formed between the diffusion plate 105 and the light emitting plate 101. Has been. That is, the light emitted from the excitation light irradiating device 70 incident on the diffusion plate 105 passes through the diffusion plate 105 and is irradiated onto the surface of the light emitting plate 101, diffusely reflected on the surface of the light emitting plate 101, and again the diffusion plate 105. Then, the light is further diffused by the diffusion plate 105 and emitted toward the TIR prism 141 shown in FIG.

  As shown in FIG. 3, the TIR prism 141 is a prism that is a combination of the first prism 142 and the second prism 143 that are two substantially triangular prisms. Has an air layer 144. The TIR prism 141 reflects the light beam incident from one predetermined surface of the first prism 142 at the boundary surface with the air layer 144 and exits from the other surface of the first prism 142, The light beam incident from the exit surface has a property of transmitting through the air layer 144 and the second prism 143. In this embodiment, the TIR prism 141 is arranged so that the light emitted from the excitation light irradiation device 70 is totally reflected in the first prism 142 and emitted toward the light emitting plate 101. In other words, the light emitted from the excitation light source 71 enters the first prism 142, is reflected by the boundary surface with the air layer 144, and is emitted toward the light emitting plate 101. The light emitted from the light emitting plate 101 is emitted from the first prism 142. The light is incident on 142, passes through the first prism 142, the air layer 144 and the second prism 143, and is emitted toward the light source side optical system 170.

  The light source side optical system 170 includes a first optical axis changing mirror 177 that converts the optical axis direction of light emitted from the light source unit 60 by approximately 90 degrees, a microlens array 171, and a light beam that has passed through the microlens array 171. A second optical axis changing mirror 173 that changes the axial direction toward the display element 51, a condensing lens 172 disposed between the second optical axis changing mirror 173 and the microlens array 171, and a second optical axis changing The condenser lens 174 is positioned on the optical axis changed by the mirror 173, and the RTIR prism 175.

  The microlens array 171 in the light source side optical system 170 converts the light bundle emitted from the light source unit 60 into a plurality of rectangular cross section light bundles that match the shape of the display element 51, and the microlens array 171 Or by a condensing lens or the like so that the central positions of the respective light bundles overlap on the display element 51, and mixing into light bundles having a uniform intensity distribution. That is, the microlens array 171 functions as a light guide device that converts an incident light beam into a light beam having a rectangular cross section and uniform intensity, such as a light tunnel or a glass rod.

  The RTIR prism 175 is a prism in which the first prism 142 and the second prism 143, which are two substantially triangular prisms like the TIR prism, are combined, and the light bundle incident from the second prism 143 is converted into the air layer 144 and the first prism. One prism 142 is transmitted and emitted from a predetermined surface of the first prism 142 to the outside, and the light beam incident from the light emitting surface of the first prism 142 is reflected by the boundary surface with the air layer 144. It has the property of injecting from other surfaces. That is, the TIR prism reflects the incident light bundle internally to change the direction of the optical axis and then transmits the incident light bundle again, whereas the RTIR prism 175 refers to the incident light bundle first. It is a prism that changes the optical axis direction of a light beam that is transmitted and then incident again. The RTIR prism 175 serves as a condenser lens that irradiates the display element 51 with light source light, and makes the projection light generated by the display element 51 coincide with the optical axis of the projection-side optical system 221 housed in the lens barrel 225. Thus, it functions as an optical axis conversion device that changes the optical axis.

  The projection-side optical system 221 built in the lens barrel 225 is composed of a fixed lens group and a movable lens group 235, and operates the lens of the movable lens group 235 in the optical axis direction by controlling the lens motor. The zoom function and focus function are realized.

  The battery 55 is a driving power source for the projector 1 and is a secondary battery that can be charged by connection with a commercial power source. As the battery 55, a secondary battery such as a lithium ion battery or a nickel metal hydride battery can be used. The projector 1 according to the present embodiment is capable of projecting with the power of the battery without connecting an electric cord or the like.

  Thus, in the projector 1 of the present embodiment, the optical layout of the light source unit 60 can be simplified by disposing the TIR prism 141 between the excitation light irradiation device 70 and the light emitting plate 101. That is, in a conventional light source unit including a light emitting plate provided with a diffusing unit and a fluorescent light emitting unit and an excitation light source that emits blue wavelength band light, blue light is transmitted between the excitation light source and the light emitting plate and red. In addition, it is necessary to arrange a dichroic mirror that reflects green. In the case of the optical layout using the dichroic mirror as described above, the light source light in the blue wavelength band needs to be guided to the light source side optical system through an optical path different from the red and green wavelength band lights. For this reason, in order to make the optical axes of the respective wavelength bands coincide with each other, at least another dichroic mirror that transmits blue and reflects red and green, or reflects blue and transmits red and green is disposed on the optical path. Had to be placed in. However, since the light source unit 60 of the present embodiment uses the TIR prism 141 instead of the dichroic mirror, even if the emission light from the excitation light source 71 and the emission light from the light emitting plate 101 are in the same wavelength band, Since there is no need to provide a dichroic mirror or to divide the optical path according to the wavelength band of light emitted from the light emitting plate 101, the optical layout can be simplified.

  Then, according to the present embodiment, the amount of members constituting the optical system in the light source unit 60 can be reduced, and the optical layout can be simplified. The projector 1 can be provided.

  The projector 1 of this embodiment is characterized in that a TIR prism 141 or an RTIR prism 141R described later is disposed between the excitation light irradiation device 70 and the light emitting plate 101, and is limited to the optical layout shown in FIG. Instead, various optical layouts can be configured. A plurality of examples relating to the optical layout will be described below. Note that the TIR prism 141 and the RTIR prism 141R differ only in whether the incident light beam is reflected first or transmitted first as described above, and in the case of this embodiment, the same function can be exhibited. A prism that can be used. In addition, since the optical axis can be adjusted by these prisms, the degree of freedom of the arrangement positions of the excitation light irradiation device 70 and the light emitting plate 101 is increased.

  6 to 9 are reference views showing different optical layouts in the projector 1 of the present embodiment. For example, as shown in FIG. 6, excitation light is incident from the second prism 143 side of the TIR prism 141 to irradiate the light emitting plate 101 with the excitation light, and the emitted light from the light emitting plate 101 is converted into the first prism 142 and the air layer. An optical layout in which the light is reflected at the boundary surface with 144 and emitted toward the first optical axis changing mirror 177 may be adopted. That is, the RTIR prism 141R may be arranged between the excitation light irradiation device 70 and the light emitting plate 101. Even in this case, the optical layout can be simplified as in the above-described embodiment.

  Further, as shown in FIG. 7, the second optical axis changing mirror 173 in FIG. 3 is eliminated, and the light bundle irradiated to the first optical axis changing mirror 177 is converted into a microlens array 171, a condensing lens 172, and a condensing lens. The display element 51 may be irradiated via the 174 and the RTIR prism 175. Further, as shown in FIGS. 8 and 9, the microlens array 171 is directly irradiated with the light emitted from the light source unit 60 emitted from the TIR prism 141 or the RTIR prism 141R without the first optical axis changing mirror 177. It is good also as a structure to be. That is, by disposing the TIR prism 141 between the excitation light source 71 and the light emitting plate 101, various optical layouts can be realized, and expensive optical systems can be reduced.

  Further, in the above-described embodiment, a circular light emitting wheel is used as the light emitting plate 101, and further, a wheel motor is used as a driving unit that sequentially moves the fluorescent light emitting unit and the diffusing unit on the optical path of the excitation light. However, a light emitting plate 101 other than a circle may be used, and an actuator or the like that operates the light emitting plate 101 in a straight line may be used as a driving unit. In other words, a rectangular light emitting plate 101 can be used, and an optical polarizer using a KTN crystal, an acoustooptic device, a MEMS mirror, or the like can be used as driving means.

  In the above-described embodiments, the TIR prism and the RTIR prism are described as examples of the prism formed by combining the first prism and the second prism. However, if there is a prism having the same function, the TIR prism or the RTIR prism is used. It is not limited to. The present invention is not limited to the above embodiments, and can be freely changed and improved without departing from the gist of the invention.

1 Projector
5 Upper case 6 Lower case
11 Top plate 12 Front plate
13 Back plate 14 Left plate
15 Right side plate 18 Air intake hole
21 I / O connector 22 I / O interface
23 Image converter 24 Display encoder
25 Video RAM 26 Display driver
31 Image compression / decompression unit 32 Memory card
37 Key / Indicator section 38 Control section
41 Light source control circuit 42 Illuminance sensor
43 Cooling fan drive control circuit 45 Lens motor
47 Audio processor 48 Speaker
51 Display element 55 Battery
60 Light source unit 70 Excitation light irradiation device
71 Excitation light source 73 Collimator lens
80 Power connector 101 Light emitter
102 Red fluorescent light emitting part 103 Green fluorescent light emitting part
104 Diffuser 105 Diffuser
106 Adhesive 107 Wheel motor
108 Dichroic mirror 109 Reflective surface
110 Condenser lens 111 Red phosphor layer
112 Green phosphor layer 130 Heat pipe
141R RTIR prism
141 TIR Prism 142 First Prism
143 Second prism 144 Air layer
170 Light source side optical system 171 Micro lens array
172 Condensing lens
173 Second optical axis change mirror 174 Condensing lens
175 RTIR prism 177 First optical axis change mirror
190 Heat sink 221 Projection side optical system
225 Lens barrel 235 Movable lens group
241 Main control circuit board 242 Power supply control circuit board
261 Cooling fan

Claims (7)

An excitation light source that emits light of a predetermined wavelength band;
A fluorescent light-emitting unit having a surface as a reflection surface, and a phosphor layer that emits light of a predetermined wavelength band using the light emitted from the excitation light source as excitation light, and a diffusion unit that diffuses the light emitted from the excitation light source, A light emitting plate having
A first prism that is disposed between the light emitting plate and the excitation light source and has a total reflection surface that adjusts an optical axis and totally reflects light, and a second prism that adjusts the optical axis and transmits light is an air layer. A prism that is combined via
With
A light source unit comprising drive means for sequentially moving the fluorescent light emitting part and the diffusing part of the light emitting plate on an optical path of excitation light via the prism. The prism is arranged such that the second prism is located on the excitation light source side and the first prism is located on the light emitting plate side,
The light emitted from the excitation light source is incident on the second prism and then transmitted, then enters the first prism through the air layer, further passes through the first prism, and is irradiated onto the light emitting plate.
The light emitted from the light emitting plate is incident on the first prism, is reflected by an interface between the first prism and the air layer, and is emitted to the outside. Light source unit. The prism is arranged such that the first prism is located on the excitation light source side and the second prism is located on the light emitting plate side,
The light emitted from the excitation light source is incident on the first prism, is reflected at the boundary surface between the first prism and the air layer, and is applied to the light emitting plate.
2. The light source unit according to claim 1, wherein light emitted from the light emitting plate is transmitted through the first prism and the second prism to be emitted to the outside. The excitation light source is a semiconductor light source that emits blue wavelength band light,
The light emitting plate has a red fluorescent light emitting portion having a red phosphor layer that receives the excitation light and emits light in a red wavelength band, and a green having a green phosphor layer that receives the excitation light and emits light in a green wavelength band. 4. The light emitting wheel according to claim 1, wherein the fluorescent light emitting part and the diffusion part for emitting the blue wavelength band light by diffusing the excitation light are arranged in a circumferential direction. The light source unit according to any one of claims.   The light source unit according to claim 1, wherein the excitation light source is a blue laser emitter.   The red fluorescent light emitting unit and the green fluorescent light emitting unit reflect red wavelength band light and green wavelength band light on the side opposite to the surface irradiated with the excitation light of the light emitting plate, and emit blue wavelength band light. 6. The light source unit according to claim 4, wherein a dichroic mirror that transmits light is disposed, and a reflection mirror that reflects light of red, green, and blue wavelength bands is disposed in the diffusing portion. The light source unit according to any one of claims 1 to 6,
A display element;
A light source side optical system for emitting light emitted from the light source unit to the display element;
A projection-side optical system that emits projection light generated by the display element toward a screen;
Projector control means for controlling the light source unit and the display element;
A projector comprising:

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