JP5429543B2 - Light source unit and projector - Google Patents

Description

  The present invention relates to a light source unit including a condensing device that condenses light emitted from a fluorescent wheel, 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. This projector focuses light emitted from a light source on a micromirror display element called DMD (digital micromirror device) or a liquid crystal plate, and displays a color image on a screen.

  Conventionally, in such projectors, a projector using a high-intensity discharge lamp as a light source has been mainstream. However, in recent years, a light emitting diode (LED), a laser diode (LD), an organic EL, or the like is used as a light emitting element of a light source device. Many developments and proposals using such semiconductor light emitting devices have been made.

  However, when a light emitting diode is used as a light source, there is a problem that the luminance is insufficient by itself. In addition, when red, green, and blue laser diodes are used as light sources, the green laser diode has poor power efficiency, and the brightness is extremely low compared to red and blue laser diodes. It was.

  Therefore, a proposal has been made that the phosphor is excited by an ultraviolet light emitting diode, a blue light emitting diode, or an ultraviolet laser diode or a blue laser diode, and the fluorescent light emitted from the phosphor is used as light source light (for example, Patent Document 1).

  In the light source device of Patent Document 1, red, green, and blue phosphor layers are arranged in parallel on the surface of a fluorescent wheel made of a translucent disk, and ultraviolet light is reflected on the surface of these phosphor layers and visible light is visible. A transmissive dichroic filter is disposed, and the phosphor layer is irradiated with ultraviolet light from the back side of the fluorescent wheel to generate light sources of red, green, and blue wavelength bands.

  Thus, in the light source device that uses the fluorescent light from the fluorescent material as the light source light, the fluorescent light is emitted from the fluorescent material in all directions, so that it is a problem to efficiently extract the fluorescent light. In addition, when the phosphor layer having a predetermined thickness is configured to be excited, if the incident surface of the excitation light is different from the emission surface of the fluorescent light, the fluorescent light is emitted from the phosphor on the incident surface side of the excitation light. There is a large difference between the amount of fluorescent light absorbed by other phosphors contained in the same layer and emitted by excitation light and the amount of fluorescent light emitted from the exit surface. There is a problem that the utilization efficiency of fluorescent light is lowered.

  In order to solve such problems, a phosphor wheel having a phosphor layer formed on a reflecting surface is provided, and excitation light is irradiated on the phosphor layer from the front of the phosphor layer to excite the phosphor. A light source device that emits fluorescent light from the same surface as the incident surface has been proposed. In this light source device, a part of the light beam that has emitted fluorescence in the vicinity of the incident surface of the excitation light is directly emitted to the outside from the same surface as the incident surface of the excitation light, and thus is not absorbed by the phosphor. Also, a part of the fluorescent light emitted in a different direction from the excitation light incident surface is reflected by the reflection surface and then emitted to the outside from the same surface as the excitation light incident surface. Compared with a configuration in which fluorescent light is emitted to the outside from a different surface, the utilization efficiency of fluorescent light can be increased.

  Further, in the light source device having the configuration in which the incident surface of the excitation light and the emission surface of the fluorescent light are the same surface, the excitation light is blue wavelength band light, and red and green wavelength band light sources are red. There has also been a proposal that uses fluorescent light from the green phosphor layer and diffuses and transmits the excitation light for the blue wavelength band light source light.

JP 2004-341105 A

  In the light source device having the fluorescent wheel in which the incident surface of the excitation light and the emission surface of the fluorescent light are the same surface as described above, the fluorescent light and the diffuse transmitted light emitted as the light bundle diffused from the fluorescent wheel are used. A condensing optical system for condensing, that is, a condensing device is required. Further, in order to increase the utilization efficiency of the light bundle emitted from the fluorescent wheel in such a light source device, it is necessary to arrange a large condenser lens in the vicinity of the emission surface of the fluorescent wheel.

  As for the fluorescent light emitted from the front side of the fluorescent wheel, there is nothing obstructing the arrangement of the condensing lens on the front side of the fluorescent wheel. Efficiency can be increased.

  However, since a wheel motor is disposed on the back side of the fluorescent wheel, a large condenser lens cannot be disposed on the back side of the fluorescent wheel because it physically interferes with the wheel motor. Therefore, with respect to the diffuse transmitted light emitted from the back side of the fluorescent wheel, a small condenser lens that does not interfere with the wheel motor is disposed. In this case, a part of the diffuse transmitted light is transmitted to the wheel motor. Irradiation causes vignetting, and the other part of the diffuse transmitted light cannot enter the condenser lens and becomes stray light. As a result, the utilization efficiency of the diffuse transmitted light decreases.

  The present invention has been made in view of such problems of the prior art, and includes a light source unit including a condensing device capable of increasing the condensing efficiency and utilization efficiency of a light bundle emitted from a fluorescent wheel, and An object of the present invention is to provide a projector capable of projecting a high-quality color image by including this light source unit.

The light source unit of the present invention is disposed so as to be orthogonal to the optical axis of the light beam emitted from the excitation light source device, and the excitation light source device including an excitation light source that emits light of a predetermined wavelength band. A fluorescent wheel that emits fluorescent light from a surface that is irradiated with light emitted from the excitation light source device and emits diffuse transmitted light from the rear surface, and a rear surface side of the fluorescent wheel A wheel motor that is arranged in the vicinity and that rotationally drives the fluorescent wheel, and a light collecting unit that converts the optical axis direction of the light beam emitted from both the front and back surfaces of the fluorescent wheel into the same optical axis direction and focuses the light on a predetermined surface An optical device, and the condensing device includes a diffused light condensing lens that condenses diffuse transmitted light emitted from the back surface of the fluorescent wheel, and the diffused light condensing lens includes the excitation light source Injected from the device It is located on the extended line of the optical axis of the bundle of rays, in the vicinity of the back surface of the fluorescent wheel and in the position closest to the side of the wheel motor, and the diffused light collecting lens is emitted from the excitation light source device On the plane orthogonal to the optical axis of the light bundle, the intersection of the plane and the optical axis of the light bundle emitted from the excitation light source device is connected to the intersection of the plane and the extension of the rotation axis of the wheel motor. The length in the vertical axis direction in the direction perpendicular to the horizontal axis direction in the plane parallel to the plane is longer than the length in the horizontal axis direction that is the same direction as one direction of the elliptical line. And

The projector of the present invention comprises the above light source unit, a light guide device, a light source side optical system, a display device, a projection side optical system includes a projector control unit, the source light emitted from the light source unit The light is condensed on the incident surface of the light guide device.

  According to the present invention, a light source unit including a condensing device capable of increasing the condensing efficiency and utilization efficiency of a light bundle emitted from a fluorescent wheel, and a high-quality color image are projected by including the light source unit. Possible projectors can be provided.

1 is an external perspective view showing a projector according to an embodiment of the invention. It is a functional circuit block diagram of the projector which concerns on the Example of this invention. 1 is a schematic plan view showing an internal structure of a projector according to an embodiment of the invention. It is a plane schematic diagram of the light source unit which concerns on the Example of this invention. It is the simple top view and simple side view of the light source unit which concern on the Example of this invention. It is a figure which shows the example of the toroidal lens which concerns on the other Example of this invention. It is a simplified top view of the light source unit which concerns on the other Example of this invention. It is a plane schematic diagram of the light source unit which concerns on the other Example of this invention.

  Hereinafter, modes for carrying out the present invention will be described. The projector 10 of the present invention includes a light source unit 63, a light source side optical system 62, a light guide device 75, a display element 51, a projection side optical system 90, and projector control means. The light source light is disposed on the incident surface of the light guide device 75 so as to be condensed.

  The light source unit 63 includes an excitation light source device 65, a fluorescent wheel 71, a wheel motor 73, and a light collecting device 74. The excitation light source device 65 includes an excitation light source 72 that emits light of a predetermined wavelength band. The fluorescent wheel 71 is disposed so as to be orthogonal to the optical axis of the light beam emitted from the excitation light source device 65, and receives the emission light from the excitation light source device 65 and is irradiated with the emission light from the excitation light source device 65. Fluorescent light is emitted from the front surface, which is the surface on the other side, and diffuse transmitted light is emitted from the back surface. Further, the wheel motor 73 is disposed in the vicinity of the back surface side of the fluorescent wheel 71 and rotates the fluorescent wheel 71.

  Then, the condensing device 74 converts the optical axis direction of the light beam emitted from both the front and back surfaces of the fluorescent wheel 71 into the same optical axis direction and condenses the light beam on a predetermined surface. The condensing device 74 includes a diffused light condensing lens 156 that condenses diffuse transmitted light emitted from the back surface of the fluorescent wheel 71. The diffused light condensing lens 156 is disposed on the extended line of the optical axis of the light bundle emitted from the excitation light source device 65, in the vicinity of the back surface of the fluorescent wheel 71, and in the position closest to the side of the wheel motor 73. ing.

This diffused light collecting lens 156 is on a plane orthogonal to the optical axis of the light beam emitted from the excitation light source device 65, and the intersection of this plane and the optical axis of the light beam emitted from the excitation light source device 65, The length in the direction perpendicular to the horizontal axis direction in the plane parallel to the plane is longer than the length in the horizontal axis direction that is the same direction as one direction of the line connecting the plane and the extension of the rotation axis of the wheel motor 73. The axial length is long.

  In the light source unit 63 of the present invention, the diffused light condensing lens 156 is a D-cut lens in which an arc portion located in the vicinity of the wheel motor 73 is cut by a string parallel to the vertical axis, and the cut portion is a wheel motor. 73 is located close to.

  In the light source unit 63 of the present invention, the excitation light source 72 is a blue laser light emitter, and the cross section of the light beam emitted from the blue laser light emitter has a diameter in a direction in which the vertical diameter is perpendicular to the vertical direction. The fluorescent wheel 71 includes a segment as a red fluorescent light emitting region in which a red phosphor layer is laid, a segment as a green fluorescent light emitting region in which a green phosphor layer is laid, and an excitation light source 72. And a segment serving as a diffuse transmission region for diffusing and transmitting the emitted light are arranged in parallel 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 10. In the present embodiment, left and right indicate the left and right direction with respect to the projection direction, front and rear indicate the front and rear direction with respect to the traveling direction of the light beam, and upper and lower indicate that the projector 10 is placed on a desk or the like. The upper and lower sides in the thickness direction are shown.

  As shown in FIG. 1, the projector 10 has a substantially rectangular parallelepiped shape, and has a lens cover 19 that covers the projection port on the side of the front panel 12 that is a side plate in front of the main body case. Is provided with a plurality of exhaust holes 17. Further, although not shown, an Ir receiver for receiving a control signal from the remote controller is provided.

  In addition, a key / indicator section 37 is provided on the top panel 11 which is a main body case. The key / indicator section 37 includes a power switch key, a power indicator for notifying power on / off, and projection on / off. A key or indicator such as a projection switch key to be switched, an overheat indicator for notifying when a light source unit, a display element, a control circuit or the like is overheated is disposed.

  In addition, on the back of the main body case, there are provided various terminals 20 such as an input / output connector portion and a power adapter plug for providing a USB terminal, a D-SUB terminal for image signal input, an S terminal, an RCA terminal, etc. on the rear panel. Yes. A plurality of intake holes 18 are formed in the vicinity of the lower portion of the right side panel 14 which is a side plate of the main body case (not shown) and the left side panel 15 which is the side plate shown in FIG.

  Next, projector control means of the projector 10 will be described with reference to the 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. Image signals of various standards input from the input / output connector unit 21 are input / output. The image conversion unit 23 converts the image signal into a predetermined format suitable for display via the interface 22 and the system bus (SB), and outputs the image signal 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. By irradiating the light beam emitted from the light source unit 63 to the display element 51 via the light source side optical system, a light image is formed by the reflected light of the display element 51, and a projection side optical system 90 described later. An image is projected and displayed on a screen (not shown) via The movable lens group 97 of the projection side optical system 90 is driven by the lens motor 45 for zoom adjustment and focus adjustment.

  The image compression / decompression unit 31 reads image data recorded on the memory card 32 in the reproduction mode, decompresses individual image data constituting a series of moving images in units of one frame, and converts the image data into the image conversion unit 23. Is output to the display encoder 24 and the processing for enabling the display of a moving image or the like based on the image data stored in the memory card 32 is performed. In the projector 10 of the present embodiment, when the card throttle is provided in the housing of the projector 10 and the memory card 32 is inserted into the card throttle, the input / output connector unit 21 is provided with the memory card 32 as a USB memory. There is a case where it is configured to be inserted.

  The control unit 38 controls operation of each circuit in the projector 10, and includes a ROM that stores operation programs such as a CPU and various settings fixedly, and a RAM that is used as a work memory. .

  An operation signal of a key / indicator unit 37 composed of a main key and an indicator provided on the upper panel 11 of the main body case is directly sent to the control unit 38, and a key operation signal from the remote controller is sent to the Ir receiving unit 35. , And the code signal demodulated by the Ir processor 36 is output to the controller 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 playback mode, and drives the speaker 48 to emit loud sounds.

  The control unit 38 also controls the light source control circuit 41. The light source control circuit 41 controls the light source unit 63 so that light of a predetermined wavelength band required at the time of image generation is emitted from the light source unit 63. To do. 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 63 and the like, and controls the rotation speed of the cooling fan from the result of the temperature detection. Further, the control unit 38 causes the cooling fan drive control circuit 43 to keep the cooling fan rotating even after the projector body is turned off by a timer or the like, or to turn off the projector body depending on the result of temperature detection by the temperature sensor. Control is also performed.

  Next, the internal structure of the projector 10 will be described. FIG. 3 is a schematic plan view showing the internal structure of the projector 10. As shown in FIG. 3, the projector 10 has a power supply control circuit board 102 with a power supply circuit block 101 and the like attached in the vicinity of the right panel 14, and a sirocco fan type blower 110 arranged in the approximate center. A control circuit board 103 is disposed near the blower 110, a light source unit 63 is disposed near the front panel 12, and an optical system unit 70 is disposed near the left panel 15.

  Further, the projector 10 is airtightly divided into an intake side space chamber 121 on the rear panel 13 side and an exhaust side space chamber 122 on the front panel 12 side by a partition wall 120 in the casing, and the blower 110 has a suction port 111 is disposed in the intake side space chamber 121 and the discharge port 113 is positioned at the boundary between the exhaust side space chamber 122 and the intake side space chamber 121.

  The optical system unit 70 includes an illumination side block 78 located in the vicinity of the light source unit 63, an image generation block 79 located on the back panel 13 side, and a projection side block located between the illumination side block 78 and the left panel 15. It is a substantially U-shape composed of 80 and 3 blocks.

  The illumination side block 78 includes a part of the light source side optical system 62 that guides the light emitted from the light source unit 63 to the display element 51 provided in the image generation block 79. As the light source side optical system 62 included in the illumination side block 78, the light guide device 75 that converts the light beam emitted from the light source unit 63 into a light beam having a uniform intensity distribution, and condenses light transmitted through the light guide device 75. There is a condensing lens.

  The image generation block 79 includes, as the light source side optical system 62, an optical axis changing mirror 76 that changes the optical axis direction of the light beam emitted from the light guide device 75, and light reflected by the optical axis changing mirror 76 as a display element. A plurality of condensing lenses for condensing on 51 and an irradiation mirror 84 for irradiating the display element 51 with a light beam transmitted through these condensing lenses at a predetermined angle. Further, the image generation block 79 includes a DMD serving as a display element 51, and a display element cooling device 53 for cooling the display element 51 is disposed on the rear panel 13 side of the display element 51. Prevents high temperatures.

  The projection-side block 80 includes a lens group of the projection-side optical system 90 that emits light that is reflected by the display element 51 and forms an image to the screen. The projection-side optical system 90 includes a fixed lens group 93 built in a fixed lens barrel and a movable lens group 97 built in a movable lens barrel, and is a variable focus lens having a zoom function, and is movable by a lens motor. Zoom adjustment and focus adjustment are enabled by moving the lens group 97.

  Next, the light source unit 63 in the projector 10 of the present embodiment will be described. FIG. 4 is a schematic plan view of the light source unit 63. As shown in FIG. 4, the light source unit 63 includes an excitation light source device 65 including a plurality of excitation light sources 72, a fluorescent wheel 71 disposed on the optical axis of the excitation light source device 65, and a rotational drive of the fluorescent wheel 71. And a light condensing device 74 that converts light bundles emitted from both the front and back surfaces of the fluorescent wheel 71 into the same optical axis direction and condenses them on a predetermined surface, that is, the incident surface of the light guide device 75. And comprising.

  The excitation light source device 65 includes a plurality of excitation light sources 72 arranged in a matrix so that the central axis of the light guide device 75 and the optical axis are parallel, and a plurality of collimator lenses 149 arranged in front of the excitation light source 72. And a reflection mirror group 150 that converts the optical axis direction of the light beam transmitted through the collimator lens 149. In this excitation light source device 65, the excitation light source 72 is a blue laser emitter that emits a laser beam in the blue wavelength band, and six blue laser emitters as the excitation light source 72 are 3 in the horizontal direction of the projector housing. They are arranged in a matrix of two stages vertically and vertically.

  Further, the collimator lens 149 emits light emitted from each blue laser light emitter in front of the plurality of blue laser light emitters in the excitation light source 72 as parallel light having increased directivity. Further, the reflection mirror group 150 includes the same number of reflection mirrors as the blue laser emitters, and each of the reflection mirrors emits light emitted from the blue laser emitters in front of each blue laser emitter. The optical axis of the emitted light from each blue laser emitter is converted so as to be condensed on the layer or the diffuse transmission layer.

  The fluorescent wheel 71 is a circular light emitting plate having an opening connected to the rotation shaft of the wheel motor 73 at the center, and the rotation is controlled by the wheel motor 73. The fluorescent wheel 71 includes a segment as a red fluorescent light emitting region that emits red wavelength band light using the emission light from the excitation light source device 65 as excitation light, and a green wavelength band light using the emission light from the excitation light source device 65 as excitation light. And a segment as a diffuse transmission region for diffusing and transmitting the light emitted from the excitation light source device 65 are juxtaposed in the circumferential direction. The fluorescent wheel 71 emits light emitted from the excitation light source device 65 so that the emission light from the excitation light source device 65 is irradiated between the opening for the wheel motor 73 and the outer peripheral edge, that is, the wheel surface. It arrange | positions in the state which slid the rotating shaft to the predetermined direction with respect to the axis | shaft.

  The surfaces of the red fluorescent light emitting region and the green fluorescent light emitting region are reflective surfaces by silver vapor deposition or the like, and the red fluorescent material layer and the green fluorescent material layer are laid on the reflective surface. Moreover, the diffuse transmission region is formed of a highly light-transmitting member such as glass, and the surface is finely uneven by sandblasting or the like.

  Then, when the emission light from the excitation light source device 65 is irradiated to the red fluorescent light emitting region and the green fluorescent light emitting region, the red fluorescent material and the green fluorescent material are excited, and the red wavelength band light and the green wavelength band light from the front, That is, it is emitted from the surface on which the excitation light is incident. In addition, when the light emitted from the excitation light source device 65 is irradiated to the diffuse transmission region, it is diffused by the fine unevenness on the surface, and the blue wavelength band light is converted from the highly directional laser light to the low directional diffused light. Injecting from the back side, that is, from the side where the wheel motor 73 is located.

  The condensing device 74 is D-cut with a mirror group 151 including a plurality of mirrors, a convex lens group 153 including a plurality of convex lenses, a fluorescent light condensing lens 155 that is a condensing lens by combining convex lenses and meniscus lenses. A diffused light collecting lens 156 and a light guide device incident lens 154 are configured.

  The mirror group 151 is on the optical axis of the excitation light reflected by the reflection mirror group 150 and is arranged on the front side of the fluorescent wheel 71, and on the back side of the fluorescent wheel 71 and on the reflection mirror group The second mirror 151b arranged at a position where the extension line of the optical axis of the excitation light reflected by 150 and the extension line of the central axis of the light guide device 75 intersect each other, and is emitted from the fluorescent wheel 71 and reflected by the first mirror 151a The third mirror 151c arranged on the optical axis of the fluorescent light, and the optical axis of the fluorescent light reflected by the third mirror 151c and the extension line of the central axis of the light guide device 75 are arranged at the intersecting positions. A fourth mirror 151d.

  The first mirror 151a is a dichroic mirror that transmits the light emitted from the excitation light source device 65 and reflects the fluorescent light emitted from the fluorescent wheel 71, that is, the light in the red and green wavelength bands. The second mirror 151b is a reflection mirror, and aligns the optical axis of the emitted light from the excitation light source 72 diffused and transmitted through the fluorescent wheel 71 with the central axis of the light guide device 75. The third mirror 151c is a reflection mirror, and reflects the red and green wavelength band lights emitted by the fluorescent wheel 71 to the fourth mirror 151d. The fourth mirror 151d is a dichroic mirror that transmits the light beam reflected by the second mirror 151b and reflects the light beam reflected by the third mirror 151c.

  The convex lens group 153 of the condensing device 74 includes a first convex lens 153a disposed between the second mirror 151b and the fourth mirror 151d, and a second disposed between the first mirror 151a and the third mirror 151c. It includes a convex lens 153b and a third convex lens 153c disposed between the third mirror 151c and the fourth mirror 151d.

  The fluorescent light condensing lens 155 of the condensing device 74 is in the vicinity of the surface of the fluorescent wheel 71, that is, in the vicinity of the incident surface of the light beam emitted from the excitation light source device 65 in the fluorescent wheel 71, and from the excitation light source device 65. It is arranged on the optical axis of the emitted light. The fluorescent light condensing lens 155 condenses the light beam emitted from the excitation light source device 65 on the wheel surface of the fluorescent wheel 71 and condenses the fluorescent light emitted from the fluorescent wheel 71 on the first mirror 151a. . The light guide device incident lens 154 of the light condensing device 74 is disposed in the vicinity of the light guide device 75 and condenses the light emitted from the light source unit 63 on the incident surface of the light guide device 75.

  The diffused light condensing lens 156 of the condensing device 74 is disposed near the back surface of the fluorescent wheel 71 and near the side of the wheel motor 73. When the diffused light condensing lens 156 is arranged so that the central axis is positioned on the large lens diameter, that is, the extension line of the optical axis of the excitation light, the arc portion of the diffused light condensing lens 156 is connected to the wheel motor 73. The size is such that it physically interferes, and a D-cut lens is obtained by cutting a portion that physically interferes with the wheel motor 73.

That is, when the diffused light collecting lens 156 is arranged so that the central axis is located on the extension line of the optical axis of the excitation light, the arc portion of the arc that physically interferes with the wheel motor 73 in the vertical direction, That is, it is cut by a string parallel to the vertical axis, and the length in the horizontal axis direction is shorter than the length in the vertical axis direction. Here, the horizontal axis direction is the intersection of the plane and the optical axis on the plane orthogonal to the optical axis of the light emitted from the excitation light source device 65, and the intersection of the plane and the rotation axis of the wheel motor 73. The vertical axis direction is a direction orthogonal to the horizontal axis direction in a plane parallel to the plane.

  The light beam emitted from the excitation light source 72 used in this embodiment is viewed from the plane direction as shown in FIG. 5A and from the side direction as shown in FIG. 5B. There is a difference in the length of the diameter in the cross-section of the light flux when viewed. In other words, the light beam emitted from the excitation light source 72 is substantially linear because of its small diameter when viewed from the plane direction as shown in FIG. As shown in FIG. 5 (b), it has a strip shape because of its large diameter. Therefore, the cross-sectional shape of the light beam emitted from the excitation light source 72 is a substantially elliptical shape having a large diameter in the vertical direction and a small diameter in the direction orthogonal to the vertical direction.

  When the light beam emitted from the excitation light source 72 having such a cross-sectional shape is irradiated and diffused through the diffuse transmission region of the fluorescent wheel 71, the diffused light is wide in the vertical direction and narrow in the direction perpendicular to the vertical direction. The light is emitted from the back side of the fluorescent wheel 71. Therefore, the lens that collects the diffusely transmitted light needs to be a lens having a wide incident surface at least in the vertical direction, that is, at least in the vertical axis direction.

  As described above, the diffused light condensing lens 156 is cut by a string parallel to the vertical axis so as to avoid physical interference with the wheel motor 73. The lens has a short length in the horizontal axis direction perpendicular to the lens. Therefore, in the light source unit 63 using the diffused light condensing lens 156, the wide lens with respect to the portion where the light beam in the vertical direction having a large cross-sectional diameter is incident in the diffuse transmitted light emitted from the fluorescent wheel 71. Compared to the case of using a condensing lens with a small diameter that does not cause physical interference with the wheel motor 73, the diffused transmitted light that becomes stray light can be reduced. it can.

  In other words, in the diffused and transmitted light emitted from the fluorescent wheel 71, a part of the light bundle emitted in the direction irradiated to the wheel motor 73 is in the vicinity of the fluorescent wheel 71 as shown in FIG. The angle with respect to the optical axis is converted by the arranged diffused light condensing lens 156 and emitted to the second mirror 151b. Therefore, the amount of light that is irradiated to the wheel motor 73 and becomes stray light is reduced.

  Further, in the diffused transmitted light emitted from the fluorescent wheel 71, the light bundle diffused widely in the vertical direction is a large-diameter condensing lens disposed in the vicinity of the fluorescent wheel 71 as shown in FIG. That is, the light enters the diffused light collecting lens 156, and the diffused light collecting lens 156 converts the angle with respect to the optical axis to be small and emits the light to the second mirror 151b. Therefore, the amount of diffuse transmitted light that can be taken in as light source light can be increased, and the light collection efficiency in the light collecting device 74 can be increased.

  In such a light source unit 63, the blue laser light emitted from the excitation light source 72 and reflected by the reflection mirror group 150 is transmitted through the first mirror 151a as shown in FIG. The red and green fluorescent reflection areas and diffuse transmission areas of the fluorescent wheel 71 are irradiated.

  In addition, the light bundle emitted from the excitation light source device 65 and applied to the red and green fluorescent emission regions excites the phosphor as excitation light, and the phosphor emits light in a predetermined wavelength band. Furthermore, the light beam emitted from the excitation light source device 65 and irradiated on the diffuse transmission region of the fluorescent wheel 71 is diffused and converted from coherent light with high directivity to incoherent light with low directivity, and incoherent. The light is emitted from the back side of the fluorescent wheel 71 as blue wavelength band light.

  Then, the fluorescent light that is fluorescently emitted on the surface of the fluorescent wheel 71 is condensed by the fluorescent light condensing lens 155 and irradiated onto the first mirror 151a. The fluorescent light irradiated to the first mirror 151a is reflected by the first mirror 151a and collected by the second convex lens 153b and the third convex lens 153c, and reflected by the third mirror 151c and the fourth mirror 151d. The light is incident on the light incident surface of the light guide device 75 by the light guide device incident lens 154 and enters the light guide device 75.

  Further, the blue wavelength band light diffused and transmitted through the fluorescent wheel 71 is collected by the diffused light collecting lens 156, irradiated to the second mirror 151b, reflected by the second mirror 151b, and collected by the first convex lens 153a. Then, after passing through the fourth mirror 151d, it is condensed on the incident surface of the light guide device 75 by the light guide device incident lens 154 and enters the light guide device 75.

  The light source light incident on the light guide device 75 is converted into a light bundle having a uniform intensity in the light guide device 75, irradiated to the optical axis change mirror 76, reflected by the optical axis change mirror 76, and reflected by the optical system unit 70. The light enters the image generation block 79, is converted into projection light by the display element 51, enters the projection side optical system 90, is enlarged by the projection side optical system 90, and is projected onto a screen or the like.

  The light source unit 63 of the present embodiment is formed as a condensing lens that condenses diffusely transmitted light emitted from the fluorescent wheel 71, and the length in the vertical axis direction is longer than the length in the horizontal axis direction perpendicular thereto. A diffused light condensing lens 156 is provided in the vicinity of the back surface of the fluorescent wheel 71 and at a position immediately adjacent to the side of the wheel motor 73. By constructing such diffused light condensing lens 156 to condense diffused and transmitted light from fluorescent wheel 71, a large amount of up-and-down light having a large spread in the cross-section of diffused and transmitted light is captured as effective light. Therefore, the light collection efficiency of the light collecting device 74 can be increased, and the light collection efficiency and utilization efficiency of diffused transmitted light can be increased.

  Further, by using such a diffused light collecting lens 156 as a diffused transmitted light collecting lens, the cross-sectional area of the diffused transmitted light emitted from the fluorescent wheel 71 can be reduced and emitted to the subsequent optical system, The condensing efficiency and utilization efficiency of the diffuse transmitted light can be increased without increasing the size of the second mirror 151b and the like.

  Further, the diffused light collecting lens 156 is a D-cut lens in which the arc portion of the string located in the vicinity of the wheel motor 73 is cut in the vertical direction. By using such a D-cut lens as a condensing lens for diffuse transmitted light, it is possible to prevent physical interference with the wheel motor 73 even with a large-diameter lens. Compared to the case where a small-diameter lens is used as a condenser lens in order to avoid physical interference with the wheel motor 73, a large amount of light beams in the vertical direction in the diffuse transmitted light can be used as effective light. As a result, it is possible to increase the light collection efficiency and utilization efficiency of diffused transmitted light. Further, by using a D-cut lens as the diffused light condensing lens 156, a large amount of light bundles emitted in the direction opposite to the wheel motor 73 can be captured, so that a large amount of diffused transmitted light is used as effective light. Can be captured

  Then, in the light source unit 63 of the present embodiment, a blue laser emitter having a characteristic of emitting a light bundle having a substantially elliptical cross section whose diameter in the vertical direction is larger than the diameter in the direction perpendicular thereto is used as the excitation light source 72. Yes. By using a blue laser emitter having such characteristics as the excitation light source 72, the cross section of the diffuse transmitted light has a light beam that is wide in the vertical direction and narrow in the direction perpendicular to the vertical direction, similarly to the blue laser emitter. . Therefore, by combining the wide beam bundle in the vertical direction and the diffused light condensing lens 156 whose length in the vertical axis direction is increased, the condensing efficiency and the utilization efficiency of the diffuse transmitted light can be increased.

  Further, by using the light source unit 63 provided with the diffused light collecting lens 156 as the diffused and transmitted light collecting lens as the light source unit 63 of the projector 10 in this way, a fluorescent light collecting lens having a large diameter with respect to the fluorescent light is used. 155 can be used to increase the use efficiency of fluorescent light, and the diffused transmitted light can be used more efficiently by sufficiently taking in the light in the vertical direction with a large amount of light. Therefore, it is possible to provide the projector 10 that can project a high-quality color image with high luminance.

  In the above-described embodiment, a D-cut lens is used as the diffused light condensing lens 156. However, as shown in FIGS. 6A and 6B, the length in the vertical axis direction is in the horizontal axis direction. A toroidal lens that is formed longer than the length and whose refractive power in the horizontal axis direction is larger than that in the vertical axis direction can also be used as the diffused light condensing lens 156.

  This toroidal lens is also called an annular lens and is a lens having different refractive powers in the vertical axis direction and the horizontal axis direction by being formed with different radii of curvature in the vertical axis direction and the horizontal axis direction. . For example, as shown in FIG. 6A, the incident light bundle is condensed in the vertical axis direction but is transmitted as it is in the horizontal axis direction, or in the horizontal axis direction as shown in FIG. 6B. There is a lens that refracts strongly and gently refracts in the vertical axis direction.

  Then, when a toroidal lens having a refractive power in the horizontal axis direction larger than that in the vertical axis direction is used as the diffused light collecting lens 156, the diffuse transmitted light emitted from the fluorescent wheel 71 is Due to the strong refractive power, a light beam having a large angle with the optical axis is converted into a light beam having a relatively small angle with the optical axis and irradiated onto the second mirror 151b. Therefore, a part of the light bundle that generates vignetting by the wheel motor 73 can be captured as effective light. Therefore, the amount of the light bundle that generates vignetting by the wheel motor 73 can be reduced, and the utilization efficiency of diffuse transmitted light can be increased. In addition, a large amount of light beams in the vertical direction with a large diffusion angle in the diffused transmitted light can be taken in as a large amount of effective light, and the utilization efficiency of the diffused transmitted light can be increased.

  Further, when such a toroidal lens is used as the diffusing and condensing lens 156, another toroidal lens can be further arranged as shown in FIG. That is, as the diffused light condensing lens 156, the first toroidal lens 157 having a refractive power in the horizontal axis direction larger than that in the vertical axis direction is used, and is on the central axis of the first toroidal lens 157. Thus, the second toroidal lens 158 is arranged in front of the wheel motor 73 in the optical axis traveling direction, and the diffused transmitted light is collected by the two toroidal lenses 157 and 158.

  The second toroidal lens 158 is formed such that the refractive power in the vertical axis direction is larger than the refractive power in the horizontal axis direction. In other words, the first toroidal lens 157 has the opposite characteristic. By using the first toroidal lens 157 and the second toroidal lens 158 in this way, the diffused transmitted light that is transmitted through the first toroidal lens 157 and narrowed in the vertical axis direction and wide in the horizontal axis direction can be The two toroidal lenses 158 can be corrected to a uniform diffusion angle, and the light beam emitted from the second toroidal lens 158 becomes a light beam with little bias in the diffusion angle.

  In the light source unit 63 in which the second toroidal lens 158 is further arranged on the optical axis of the first toroidal lens 157 as the diffused light condensing lens 156 as described above, similarly to the case where the D-cut lens is used, the diffuse transmitted light is used. The physical interference between the condenser lens and the wheel motor 73 can be avoided, and a large amount of light flux in the vertical direction in the diffuse transmitted light can be captured as effective light. Can be increased.

  In the light source unit 63 described above, a blue wavelength band light is irradiated to the fluorescent wheel 71 in which the red fluorescent light emitting region, the green fluorescent light emitting region, and the diffuse transmission region are arranged in the circumferential direction. However, for example, when the amount of light emitted from the red phosphor layer laid in the red fluorescent light emitting region is small, the green fluorescent light emitting region and the diffuse transmission region are surrounded. It is also possible to use a fluorescent wheel 71 arranged in parallel in the direction and separately arrange the red light emitting elements independently.

  That is, as shown in FIG. 8, a red light emitting element 77 is disposed between the excitation light source 72 and the fluorescent wheel 71, the optical axis of the light emitted from the red light emitting element 77, the light emitted from the excitation light source 72, and the green color. The first mirror 151a that transmits the red and blue wavelength band light and reflects the green wavelength band light may be disposed at a position where the optical axis of the wavelength band light intersects.

  As described above, even in the case of using the light source unit 63 configured to arrange an independent light emitting element for the red wavelength band light, the diffused transmitted light is collected by the diffused light condensing lens 156 as in the above-described embodiment. By using the light, the utilization efficiency of the diffuse transmitted light can be increased. Therefore, since the luminance of the light source light in the red, green, and blue wavelength bands is increased, it is possible to provide the projector 10 that can project a high-quality color image with high luminance.

  In addition, this invention is not limited to the above Example, A change and improvement are freely possible in the range which does not deviate from the summary of invention.

10 Projector 11 Top panel
12 Front panel 13 Back panel
14 Right panel 15 Left panel
17 Exhaust hole 18 Intake hole
19 Lens cover 20 Various terminals
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
35 Ir receiver 36 Ir processor
37 Key / Indicator section 38 Control section
41 Light source control circuit 43 Cooling fan drive control circuit
45 Lens motor 47 Audio processor
48 Speaker 51 Display element
53 Display element cooling device 62 Light source side optical system
63 Light source unit 65 Excitation light source device
70 Optics unit
71 Fluorescent wheel 72 Excitation light source
73 Wheel motor 74 Condenser
75 Light guide device 76 Optical axis change mirror
77 Red light emitting element
78 Lighting block 79 Image generation block
80 Projection side block 84 Irradiation mirror
90 Projection side optical system 93 Fixed lens group
97 Movable lens group 101 Power supply circuit block
102 Power supply control circuit board 103 Control circuit board
110 Blower 111 Air inlet
113 Discharge port 120 Partition wall
121 Inlet side space 122 Exhaust side space
149 Collimator lens 150 Reflective mirror group
151 mirror group 151a first mirror
151b Second mirror 151c Third mirror
151d Fourth mirror 153 Convex lens group
153a First convex lens 153b Second convex lens
153c Third convex lens 154 Light guiding device incident lens
155 Fluorescent light condensing lens 156 Diffuse light condensing lens
157 1st toroidal lens 158 2nd toroidal lens

Claims (6)

An excitation light source device comprising an excitation light source that emits light of a predetermined wavelength band;
A surface that is arranged so as to be orthogonal to the optical axis of the light beam emitted from the excitation light source device, and is a surface on the side that receives the emission light from the excitation light source device and is irradiated with the emission light from the excitation light source device A fluorescent wheel that emits fluorescent light from the back and emits diffuse transmitted light from the back surface;
A wheel motor that is disposed near the back side of the fluorescent wheel and that rotates the fluorescent wheel;
A light collecting device that converts the optical axis direction of the light bundle emitted from the front and back surfaces of the fluorescent wheel into the same optical axis direction and focuses the light on a predetermined surface, and
The condensing device includes a diffused light condensing lens that condenses diffuse transmitted light emitted from the back surface of the fluorescent wheel,
The diffused light condensing lens is disposed on the extended line of the optical axis of the light beam emitted from the excitation light source device, in the vicinity of the back surface of the fluorescent wheel and in the position closest to the side of the wheel motor. ,
The diffused light condensing lens is on a plane orthogonal to the optical axis of the light beam emitted from the excitation light source device, and the intersection of the plane and the optical axis of the light beam emitted from the excitation light source device; Rather than the length in the horizontal direction that is the same direction as one direction of the line connecting the plane and the intersection of the rotation axis of the wheel motor, the direction perpendicular to the horizontal axis direction in the plane parallel to the plane. A light source unit characterized in that the length in the vertical axis direction is long.   The diffused light condensing lens is a D-cut lens in which an arc portion located in the vicinity of the wheel motor is cut by a string parallel to the longitudinal axis, and the cut portion is disposed close to the wheel motor. The light source unit according to claim 1, wherein:   2. The light source unit according to claim 1, wherein the diffused light condensing lens is a toroidal lens having a refractive power in the horizontal axis direction larger than a refractive power in the vertical axis direction. The excitation light source is a blue laser emitter,
The cross section of the light beam emitted from the blue laser emitter has a diameter in the vertical direction larger than the diameter in the direction perpendicular to the vertical direction,
The fluorescent wheel diffuses and transmits a segment as a red fluorescent light emitting region where a red phosphor layer is laid, a segment as a green fluorescent light emitting region where a green phosphor layer is laid, and light emitted from the excitation light source. The light source unit according to any one of claims 1 to 3 , wherein segments as the diffuse transmission region are arranged side by side in a circumferential direction. The excitation light source is a blue laser emitter,
The cross section of the light beam emitted from the blue laser emitter has a diameter in the vertical direction larger than the diameter in the direction perpendicular to the vertical direction,
The fluorescent wheel includes a segment as a green fluorescent light emitting region in which a green phosphor layer is laid and a segment as the diffuse transmission region that diffuses and transmits the light emitted from the excitation light source in the circumferential direction. Become
A red light emitting element that emits red wavelength band light so as to be orthogonal to an optical axis of green wavelength band light emitted from the fluorescent wheel is provided between the excitation light source and the fluorescent wheel. The light source unit according to claim 1 . A light source unit, a light guide device, a light source side optical system, a display element, a projection side optical system, and a projector control means,
The light source unit is the light source unit according to any one of claims 1 to 5 , wherein the light source light emitted from the light source unit is condensed on an incident surface of the light guide device. Characteristic projector.

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