JP2015121597A - Projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently irradiate an image forming surface of a display element with a beam flux of light-source light.SOLUTION: An image forming surface 51a of a display element 51 is arranged with its long side 51a1 horizontally, in accordance with a projection image to be projected on a horizontally-long rectangle. A blue laser diode 71 constituting a blue light source device 70 emits a light beam having an elliptical cross section. The light emitted from the blue laser diode 71 is made incident on the display element 51 so that a long axis in the elliptical cross section of the emitted light is substantially parallel with the long side 51a1 of the rectangle in the image forming surface 51a of the display element 51.

Description

  The present invention relates to a projection apparatus having a light source including a laser diode.

  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 a projection apparatus, a display element in which a large number of micromirror surfaces (micromirrors) called DMD (digital micromirror device) that emits projection image light when irradiated with light emitted from a light source is arranged in a plane. Is being used. In the projection apparatus using the DMD, a projection apparatus having a light source device including a laser diode (LD) as a high-luminance light source has been developed so that clear projection light can be obtained even in a bright place.

  Then, as shown in Patent Document 1, the applicant of the present invention is a projector that is a projection device in which a laser emitter that emits blue light is used as a light source, and a blue wavelength band light emitted by the blue laser emitter is emitted from the projector. A projection apparatus that irradiates an image forming surface of a DMD that is a display element through various optical devices together with light in other wavelength bands has been proposed and implemented.

  In the projector disclosed in Patent Document 1, a total of 24 blue laser diodes, which are blue laser emitters, are arranged in a matrix of 3 rows and 8 columns, with 3 in the vertical direction and 8 in the front and rear direction of the projector. Yes. This blue laser emitter emits light from the right side to the left side of the projector so that the optical axis of the laser beam is parallel to the rear panel, and this laser beam is converted by the reflection mirror to 90 ° optical axis. And injected to the front panel side.

  This reflecting mirror uses eight rectangular reflecting mirrors that are long in the vertical direction so that the laser light from three vertically arranged laser emitters is reflected by one reflecting mirror, and eight reflecting mirrors are used. When the light from each laser emitter, which has been arranged in a stepwise manner in the front-rear direction, is reflected to the front panel side, the front-rear direction is more than twice as long as the front-rear direction. In addition, 24 laser beams are concentrated in a slightly wide width in the left-right direction.

  Here, in general, a laser diode has different emission angles in a vertical direction and a horizontal direction with respect to a junction surface of the diode. For this reason, it is known that the cross section of the emitted light emitted from the laser diode is elliptical. The light bundle from the light source formed as a collection of emitted light having an elliptical cross section reaches the DMD through a lens, a phosphor of a fluorescent wheel, a mirror, a light tunnel, etc., and is irradiated. Even in these optical devices, the beam bundle maintains the shape of the elliptical section of the light emitted from each laser diode and the direction of the rotation direction of the optical axis as it is.

  Moreover, the light source disclosed in Patent Document 1 is a reflection mirror that is arranged so that the long side of the rectangle is in the vertical direction, and reflects the light emitted from the blue laser diode. Therefore, the laser light emitted from the diode is attached so that it becomes a vertically long ellipse so that the width of the reflecting mirror is not widened, and the light beam from the light source reaches the DMD and is irradiated. The light bundles are formed as a set of light aligned with the major axis of the elliptical section in the vertical direction.

  On the other hand, on the image forming surface of the DMD which is a display element, a large number of micromirrors corresponding to the number of pixels of the image are arranged in a horizontally long rectangle. The image forming surface on which the micromirrors are arranged is arranged with the long side facing the projection device so that the projection image light is a horizontally long rectangle in accordance with the aspect ratio of the image.

JP 2013-80055 A

  In the prior art disclosed in Patent Document 1, a light bundle from a light source having an elliptical cross section with a long axis aligned vertically is irradiated onto an image forming surface of a DMD having long sides arranged in a horizontal direction. Therefore, both major axis directions are different. Then, the intensity of irradiation light on the image forming surface of the DMD varies, and the energy efficiency on the image forming surface of the DMD is deteriorated. As a result, this causes color unevenness in the projected image.

  The projection device of the present invention has a light source provided with a plurality of laser diodes, and a display element that irradiates an image forming surface in which a light beam from the light source is formed in a rectangular shape, and the light emitted from the laser diode Are characterized in that they are incident on the display element so that the long axis of the cross-sectional ellipse of the emitted light is substantially parallel to the long side of the image forming surface of the display element.

  According to the present invention, the major axis direction of the image forming surface of the DMD can be matched with the major axis direction of the emitted light emitted from the laser diode having an elliptical cross section. Therefore, it is possible to provide a projection device that does not cause color unevenness in the projected image.

It is an external appearance perspective view which shows the projector which concerns on embodiment of this invention. It is a functional block diagram of the projection apparatus which concerns on embodiment of this invention. It is a plane schematic diagram which shows the internal structure of the projection apparatus which concerns on embodiment of this invention. It is a perspective view which shows a part of internal structure of the projector which concerns on embodiment of this invention. It is the schematic diagram which looked at the arrangement | positioning of the laser diode and reflection mirror of the projector which concerns on embodiment of this invention. It is a schematic diagram which shows the emitted light of the laser diode of the projection apparatus which concerns on embodiment of this invention. It is a figure which shows the display element of the projector which concerns on embodiment of this invention, (a) is a plane schematic diagram which shows the image formation surface of a display element, (b) is a part of image formation surface of a display element. It is an enlarged plan schematic diagram shown.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is an external perspective view of the projection apparatus 10. In the present embodiment, left and right in the projection device 10 indicate the left and right direction with respect to the projection direction, and front and rear indicate the screen side direction of the projection device 10 and the front and rear direction with respect to the traveling direction of the light beam.

  As shown in FIG. 1, the projection device 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 housing of the projection device 10. The front panel 12 is formed with a plurality of intake holes 18. Further, although not shown, an Ir receiver for receiving a control signal from the remote controller is provided.

  Further, a key / indicator unit 37 is provided on the top panel 11 of the casing, and the key / indicator unit 37 switches a power switch key, a power indicator for notifying power on / off, and switching on / off of projection. Keys and indicators such as an overheat indicator for notifying when a projection switch key, a light source unit, a display element, a control circuit, etc. are overheated are arranged.

  In addition, on the rear surface of the housing, 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 rear panel. A plurality of exhaust holes 17 are formed in each of the right panel, which is a side plate of the casing (not shown), and the left panel 15, which is the side plate shown in FIG. An intake hole 18 is also formed in a corner near the back panel of the left panel 15.

  Next, the projection device control means of the projection device 10 will be described with reference to the functional block diagram of FIG. The projection device 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 projection apparatus 10 and includes a ROM that stores operation programs such as a CPU and various settings in a fixed manner, and a RAM that is used as a work memory. ing.

  The image signal of various standards input from the input / output connector unit 21 by the projection device 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). Are converted into a uniform image signal and then 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 driving unit 26.

  The display driving unit 26 functions as a display element control unit, and drives the display element 51 that is a spatial light modulation element (SOM) at an appropriate frame rate in accordance with the image signal output from the display encoder 24. Is. Then, the projection apparatus 10 transmits the light bundle emitted from the light source unit 60, that is, the light bundle condensed on a predetermined surface by the light source side optical system of the light source unit 60 through the light guide optical system. By irradiating the image forming surface 51a (see FIG. 7), an optical image is formed by the reflected light of the display element 51, and an image is projected and displayed on a screen (not shown) via a projection side optical system described later. 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 performs a recording process in which the luminance signal and the color difference signal of the image signal are data-compressed by a process such as ADCT and Huffman coding, and are sequentially written in a memory card 32 that is a detachable recording medium. Further, the image compression / decompression unit 31 reads the 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 via the image data, and processing for enabling display of a moving image or the like is performed based on the image data stored in the memory card 32.

  Then, an operation signal of a key / indicator unit 37 composed of a main key and an indicator provided on the top panel 11 of the housing is directly sent to the control unit 38, and a key operation signal from the remote controller is received by Ir. The code signal received by the unit 35 and demodulated by the Ir processing unit 36 is output 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 playback 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 unit. The light source control circuit 41 individually emits light from the excitation light irradiation device, the red light source device, and the blue light source device of the light source unit 60 so that the light source light of a predetermined wavelength band required at the time of image generation is emitted from the light source unit 60. To control.

  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 control unit 38 causes the cooling fan drive control circuit 43 to keep the cooling fan rotating even after the projector apparatus power is turned off by a timer or the like, or depending on the temperature detection result by the temperature sensor, Control such as turning it off is also performed.

  Next, the internal structure of the projection apparatus 10 will be described with reference to FIGS. FIG. 3 is a schematic plan view showing the internal structure of the projection apparatus 10. FIG. 4 shows a blue light source device 70, a fluorescent wheel device 100, a red light source device 120, etc. that are the light source unit 60 of the projection device 10, and an illumination side block 161, an image generation block 165, and a projection side block 168 that are optical system units 160. It is a perspective view which shows arrangement | positioning. The projection apparatus 10 includes a control circuit board 241 in the vicinity of the right panel 14. The control circuit board 241 includes a power circuit block, a light source control block, and the like. In addition, the projection device 10 includes a light source unit 60 at the side of the control circuit board 241, that is, at a substantially central portion of the housing of the projection device 10. Further, the projection apparatus 10 includes an optical system unit 160 formed by an image generation block 165, a projection side block 168, and the like between the light source unit 60 and the left panel 15.

  The light source unit 60 includes a blue light source device 70 disposed in the vicinity of the rear panel 13 at a substantially central portion in the left-right direction of the projection device 10 housing, and an optical axis of a light beam emitted from the blue light source device 70. The fluorescent wheel device 100 disposed near the front panel 12, the red light source device 120 disposed between the blue light source device 70 and the fluorescent wheel device 100, and the emitted light and red light source from the fluorescent wheel device 100. A light source-side optical system 140 that converts the optical axis of the light emitted from the device 120 so as to be the same optical axis, and collects each color light at the entrance of the light tunnel 175 that is a predetermined surface.

  In the blue light source device 70, the emitted light from the blue laser diode 71 as shown in FIG. 5 is emitted from the upper surface of the housing of the projection device 10 toward the lower surface. As shown in FIG. 5, the plurality of blue laser diodes 71 are arranged so that a total of 24 blue laser diodes 71 form 3 rows and 8 columns. A reflection mirror 75 is disposed so as to face each row of the blue laser diodes 71. The plurality of reflection mirrors 75 are fixed to a step-like plate-like member (not shown). 3 and 4, a blue laser diode 71 is fixed on the back side of the holder 83.

  3 and 4, the plurality of blue laser diodes 71 shown in FIG. 5 are fixed to the holder 83, and the reflection mirror 75 is fixed to a stepped plate-like member containing, for example, aluminum on the opposite side of the holder 83. Has been. At this time, the step-like plate-like member to which the reflection mirror 75 is fixed is arranged below the laser diode 71 so as to overlap the holder 83. Then, the stepped plate-like member is inclined and arranged so as to approach the lower surface side of the housing of the projector 10 as it goes to the fluorescent wheel device 100 side. Therefore, the distance between the blue laser diode 71 and the reflection mirror 75 is gradually increased toward the fluorescent wheel device 100 side. The optical axis of the light emitted from each blue laser diode 71 is converted by 90 degrees in the direction of the front panel 12 by the reflecting mirrors 75 which are rectangular in the left-right direction and eight are arranged in the front-rear direction.

  As shown in FIGS. 3 and 4, the upper surface of the holder 83 is connected to the heat pipe 81. The heat pipe 81 is connected to the cooling fins 82. A cooling fan 261 is disposed between the cooling fin 82 and the back panel 13, and the working fluid in the heat pipe 81 is cooled by the cooling fan 261 and the cooling fin 82. For example, the heat pipe 81 is formed by forming a wick for liquid reflux as a capillary structure, providing a steam passage tube in the center, using pure water, perfluorocarbon, or the like as a working fluid, and using a pipe whose inside is vacuum. Can do.

  The fluorescent wheel device 100 in the green light source device 80 is arranged in parallel with the front panel 12, that is, the fluorescent wheel 101 arranged so as to be orthogonal to the optical axis of the light emitted from the blue light source device 70, and the fluorescent wheel. A wheel motor 110 that rotationally drives 101, and a condenser lens that condenses the light bundle emitted from the blue light source device 70 onto the fluorescent wheel 101 and condenses the light bundle emitted from the fluorescent wheel 101 toward the rear panel 13. A group 107 and a condensing lens 115 that condenses the light bundle emitted from the fluorescent wheel 101 toward the front panel 12.

  The fluorescent wheel 101 receives emission light from the blue light source device 70 as excitation light and emits fluorescent emission light in the green wavelength band, and a diffuse transmission region that diffuses and transmits emission light from the blue light source device 70. And are arranged side by side in the circumferential direction. Further, the surface on the rear panel 13 side of the fluorescent wheel 101 in the green fluorescent emission region is mirror-processed by silver vapor deposition or the like, and a band-shaped green phosphor layer is laid on the mirror-processed surface. Furthermore, fine irregularities are formed on the surface of the fluorescent wheel 101 in the diffuse transmission region by sandblasting or the like.

  The emitted light from the blue light source device 70 irradiated on the green phosphor layer of the phosphor wheel 101 excites the green phosphor, which is a phosphor emitter in the green phosphor layer, and emits fluorescence in all directions from the green phosphor. The emitted light is directly emitted to the rear panel 13 side or after being reflected from the surface of the fluorescent wheel 101 and then emitted to the rear panel 13 side and enters the condenser lens group. In addition, the light emitted from the blue light source device 70 irradiated on the diffuse transmission region of the fluorescent wheel 101 enters the condenser lens as diffuse transmitted light diffused by the fine unevenness. A cooling fan 261 is disposed between the wheel motor 110 and the front panel 12, and the fluorescent wheel 101 is cooled by the cooling fan 261.

  The red light source device 120 is a monochromatic light emitting device that includes a red light source 121 disposed so that the optical axis is parallel to the front panel 12 and a condenser lens group 125 that collects light emitted from the red light source 121. is there. The red light source 121 is a red light emitting diode that emits light in the red wavelength band. The red light source device 120 is disposed so that the light beams emitted from the blue light source device 70 and the green wavelength band light emitted from the fluorescent wheel 101 intersect the optical axis. Furthermore, the red light source device 120 includes a heat sink 130 disposed on the right panel 14 side of the red light source 121. A cooling fan 261 is disposed between the heat sink 130 and the front panel 12, and the red light source 121 is cooled by the cooling fan 261.

  The light source side optical system 140 includes a condensing lens that condenses the light bundles in the red, green, and blue wavelength bands, and a reflection mirror that converts the optical axes of the light bundles in the respective color wavelength bands into the same optical axis, It consists of a dichroic mirror. Specifically, at a position where the blue wavelength band light emitted from the blue light source device 70 and the green wavelength band light emitted from the fluorescent wheel 101 intersect the red wavelength band light emitted from the red light source device 120, A first dichroic mirror 141 that transmits blue and red wavelength band light, reflects green wavelength band light, and converts the optical axis of the green light by 90 degrees toward the left panel 15 is disposed.

  Further, on the optical axis of the blue wavelength band light transmitted through the fluorescent wheel 101, that is, between the condenser lens 115 and the front panel 12, the blue wavelength band light is reflected and the optical axis of the blue light is changed to the left panel. A first reflecting mirror 143 that converts 90 degrees in 15 directions is arranged. Further, on the optical axis of the blue wavelength band light reflected by the first reflecting mirror 143 and in the vicinity of the optical system unit 160, a second reflecting mirror for converting the optical axis of the blue light by 90 degrees in the direction of the back panel 13 is provided. 145 is arranged.

  Further, the optical axis of the red wavelength band light transmitted through the first dichroic mirror 141, the optical axis of the green wavelength band light reflected by the first dichroic mirror 141 so as to coincide with the optical axis, and the second reflection mirror 145 At the position where the optical axis of the reflected blue wavelength band light intersects, the blue wavelength band light is transmitted, the red and green wavelength band lights are reflected, and the optical axes of the red and green light are 90 degrees toward the rear panel 13. A second dichroic mirror 148 that performs degree conversion is disposed. A condensing lens is disposed between the dichroic mirror and the reflecting mirror. Further, in the vicinity of the light tunnel 175, a condenser lens 173 that condenses the light source light at the entrance of the light tunnel 175 is disposed.

  The optical system unit 160 includes an illumination side block 161 located on the left side of the blue light source device 70, an image generation block 165 located near the position where the back panel 13 and the left panel 15 intersect, and the light source side optical system 140. And the projection side block 168 located between the left side panel 15 and the left side panel 15 are formed in a substantially U-shape.

  The illumination side block 161 includes a part of a light guide optical system 170 that guides the light source light emitted from the light source unit 60 to the display element 51 included in the image generation block 165. As the light guide optical system 170 included in the illumination side block 161, the light tunnel 175 that uses the light flux emitted from the light source unit 60 as a light flux having a uniform intensity distribution, and the light emitted from the light tunnel 175 are condensed. A condensing lens 178 and an optical axis conversion mirror 181 for converting the optical axis of the light beam emitted from the light tunnel 175 in the direction of the image generation block 165 are incorporated.

  As the light guide optical system 170, the image generation block 165 includes a condensing lens 183 that condenses the light source light reflected by the optical axis conversion mirror 181 on the display element 51, and a light beam that has passed through the condensing lens 183 as a display element. And an irradiation mirror 185 for irradiating the laser beam toward 51. Further, the image generation block 165 includes a DMD serving as the display element 51, and a heat sink 190 for cooling the display element 51 is disposed between the display element 51 and the back panel 13. The display element 51 is cooled. Further, a condenser lens 195 as the projection side optical system 220 is disposed in the vicinity of the front surface of the display element 51. As shown in FIG. 7, the display element 51 is arranged such that the image forming surface 51 a is formed in a rectangular shape and the long side 51 a is in the left-right direction.

  As shown in FIGS. 3 and 4, the projection-side block 168 includes a lens group of the projection-side optical system 220 that emits ON light reflected by the display element 51 to the screen. The projection-side optical system 220 includes a fixed lens group 225 built in the fixed lens barrel and a movable lens group 235 built in the 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 possible by moving the lens group 235.

  Next, the arrangement of the blue laser diode 71 and the reflection mirror 75 in the blue light source device 70 will be described with reference to FIG. In FIG. 5, the left side with respect to the paper surface is the upper surface side of the projection device 10.

  The blue laser diodes 71 are fixed to the holder 83 (see FIG. 4) so as to be arranged in a matrix of 3 rows and 8 columns (24 in total). On the optical axis of each blue laser diode 71, although not shown, a collimator lens that is a condensing lens that converts light emitted from each blue laser diode 71 into parallel light is disposed. The reflection mirror 75 is provided so as to face each row of the plurality of blue laser diodes 71.

  The reflection mirror 75 formed in a strip-like rectangle is arranged in the left-right direction of the projection device 10 so that the long side of the reflection mirror 75 is along the row of each blue laser diode. The reflection mirror 75 disposed facing the row formed by the three blue laser diodes 71 is a direction in which the light emitted from the blue light source device 70 is emitted (the front panel 12 which is a downward direction with respect to the paper surface). A total of eight sheets are arranged in a staircase pattern so as to expand toward the side). Although not shown, these reflecting mirrors 75 are fixed to a plate-like member having a step shape formed in a plate shape. The light emitted from each blue laser diode 71 is provided in the emission direction of the blue light source device 70 so that the cross-sectional area of the light beam in each column is reduced in one direction and formed without gaps (not shown). It is emitted to the condenser lens.

  Here, the blue laser diodes 71 of the plurality of blue laser diodes 71 are arranged in parallel to each other. The blue laser diode 71 is generally formed in an elliptical cross section as shown in FIG. Therefore, each of the blue laser diodes 71 has the long axis of the ellipse P of the emitted light substantially parallel to the long side of the reflection mirror 75 formed in a rectangle, and the emitted light, that is, the ellipse P is applied to the reflection mirror 75. Arranged to fit. Then, the light bundles emitted from the blue laser diodes 71 in each row are within the reflection surface of the reflection mirror 75 and are reflected without waste. In this way, since all the blue laser diodes 71 and the reflection mirror 75 are arranged, the light beam emitted from the blue light source device 70 has the long axis in the elliptical shape of the emitted light parallel to the plane in FIG. The projection device 10 is aligned in the left-right direction (in other words, laterally with respect to the projection device 10) and emitted.

  The light beam emitted from the blue light source device 70 whose elliptical direction is aligned laterally with respect to the projection device 10 maintains the position in the rotational direction with respect to the optical axis (in other words, the cross-sectional ellipse of the emitted light). While maintaining the orientation of the shape), the light is condensed by the condenser lens 195 via the light source side optical system 140 and the light guide optical system 170 and irradiated onto the image forming surface 51 a of the display element 51. On the other hand, as described above, the image forming surface 51a of the digital micromirror device (DMD), which is the display element 51, as shown in FIG. 7A, has a rectangular long side 51a1 having a long side 51a1 and a short side 51a2. It arrange | positions so that it may become the left-right direction with respect to the projection apparatus 10 shown in FIG.

  Therefore, the orientation of the major axis of the cross section of the ellipse P of the light emitted from the blue light source device 70 irradiated to the image forming surface 51a of the display element 51 is the same as the long side 51a1 of the rectangle on the image forming surface 51a of the display element 51. The image forming surface 51a of the display element 51 is irradiated so as to be substantially parallel. In other words, as shown in FIG. 6, the cross-section of the light emitted from the blue laser diode 71 as the light source is a long axis of an elliptical P, and the digital micro that is the display element 51 as shown in FIG. The image forming surface 51a of the display element 51 is irradiated with light emitted from the light source in the same manner as the long axis direction of the rectangle on the image forming surface 51a of the mirror device (DMD). FIG. 7B is an enlarged plan view of a Q portion in FIG. 7A of a digital micromirror device (DMD) which is a display element 51 in which a large number of micromirrors 51b are arranged.

  The emitted light from the blue light source device 70 is also used as excitation light for the green phosphor layer of the fluorescent wheel 101 that generates green wavelength band light. In the present embodiment, the light beam emitted from the blue light source device 70 is obtained by aligning the direction of the long axis in the cross-sectional ellipse of the emitted light of each blue laser diode 71 with the projection device 10 in the horizontal direction, and the fluorescent wheel 101. Is incident on. Therefore, also in the light bundle of the green wavelength band light emitted from the fluorescent wheel 101, the direction of the major axis in the cross sectional ellipse of the emitted light is aligned horizontally with respect to the projection device 10. Similarly, the light bundle emitted from the fluorescent wheel 101 is also used in the light source side optical system 140 and the light guide optical system while maintaining the position of the major axis of the elliptical cross section in the rotational direction with respect to the optical axis. Through 170, the image forming surface 51 a of the display element 51 is irradiated. Then, the major axis of the elliptical cross section of the light emitted from the blue laser diode in the green wavelength band light and the long side 51a1 of the rectangle on the image forming surface 51a of the display element 51 are substantially parallel to each other. The image forming surface 51a is irradiated. In other words, the long axis direction of the elliptical cross section of the light emitted from the light source is the same as the long axis direction of the rectangle on the image forming surface of the display element 51, and the light emitted from the light source is the image forming surface of the display element 51. 51a is irradiated.

  In this embodiment, the emission direction of the blue laser diode 71 is arranged so as to be emitted from the upper surface of the projection device 10 toward the lower surface, but it is emitted from the lower surface of the projection device 10 toward the upper surface. You may arrange. Further, the rectangular display elements 51 are arranged so that the short sides thereof are arranged in the left-right direction, and in accordance with this, the emission direction of the blue laser diode 71 is from the left side to the right side with respect to the projection device 10, or You may arrange | position from the right side to the left side. That is, the long axis of the cross-sectional ellipse of the emitted light of each blue laser diode 71 is arranged so as to be substantially parallel to the long side 51a1 of the image forming surface 51a of the rectangular display element 51 (in other words, the cross-sectional ellipse is If the rectangular major axes are arranged in the same manner, the present invention can be implemented.

  In the present embodiment, the cooling device for the blue light source device 70 is configured by the heat pipe 81 and the cooling fin 82, but may be cooled by a heat sink.

  As described above, the projection apparatus 10 in this embodiment includes the blue light source device 70 that is a light source provided with a plurality of blue laser diodes 71 whose emission light has an elliptical cross section, and the display element 51 that is a DMD. The emitted light of the blue laser diode 71 is incident so that the long axis of the elliptical cross section of the emitted light is substantially parallel to the long side 51a1 of the image forming surface 51a of the display element 51 formed in a rectangular shape.

  As a result, the emission light having a horizontally long cross-sectional ellipse is irradiated to the display element having a horizontally long rectangle with the same long axis direction. Compared with the case of irradiation, the light source light is uniformly irradiated without waste. Therefore, color unevenness of the projected image can be eliminated, the intensity of reflected light per unit area on the image forming surface of the display element can be improved, and a bright projected image can be obtained.

  Further, the laser diodes of the plurality of blue laser diodes 71 are arranged in parallel to each other. Thereby, the reduction of color unevenness and the improvement of the brightness of the projected image can be realized more reliably.

  The light bundle irradiated on the image forming surface 51 a of the display element 51 includes a light bundle of green wavelength band light emitted from a fluorescent light emitter that uses excitation light emitted from the blue laser diode 71 as excitation light. Thus, not only the laser diode as a light source, but also focusing on the fact that the laser diode light has a high intensity, the present invention can be suitably implemented even when used as excitation light of a fluorescent light emitter. it can.

  In addition, a rectangular reflection mirror 75 is disposed on the optical path from the blue light source device 70 as a light source to the display element 51. The direction of the blue laser diode 71 is aligned so that the long axis of the elliptical cross section of the light emitted from the blue laser diode 71 is substantially parallel to the long side of the reflection mirror. As a result, the emitted light having an elliptical cross section of the blue laser diode is irradiated and reflected even on the rectangular reflection mirror without waste. Therefore, since the loss of the light beam can be reduced even on the optical path of the light beam emitted from the blue light source device toward the display element, it is possible to provide a projection device with improved light source energy efficiency.

  The reflection mirror 75 is fixed to a stepped plate member, the plurality of blue laser diodes 71 are fixed to a holder 83, and the stepped plate member and the holder 83 are arranged so as to overlap each other when viewed from above. ing. Thereby, each apparatus in the housing of a projection apparatus can be arranged orderly, and the assembly work efficiency in manufacture can also be improved.

  The blue laser diode 71 is emitted from the upper surface toward the lower surface, and the reflection mirror 75 is disposed on the lower surface so as to face the blue laser diode 71 so as to reflect the emitted light of the blue laser diode 71. Yes. Thereby, since the back surface of the laser diode that needs to be cooled can be directed to the upper surface side, an arrangement that is advantageous for heat dissipation can be obtained in terms of the layout inside the projector. In addition, since an apparatus for cooling the laser diode can be arranged on the back side of the laser diode, it is possible to improve assembly work efficiency in manufacturing the projection apparatus.

The blue laser diode 71 is cooled by a heat pipe. Thus, the laser diode can be reliably cooled without increasing the thickness of the light source device in the vertical direction while arranging the light source device according to the internal layout of the projection device.
Furthermore, although the example using a micromirror device (DMD) was shown as a display element, it is not restricted to this, You may use other display elements, such as a liquid crystal.

  Further, the embodiment described above is presented as an example, and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

The invention described in the first claim of the present application will be appended below.
[1] A light source provided with a plurality of laser diodes, and a display element that irradiates an image forming surface in which a light beam from the light source is formed in a rectangular shape, and the emitted light of the laser diode is emitted light The projection device is characterized in that the long axis of the cross sectional ellipse is incident on the display element so as to be substantially parallel to the long side of the image forming surface of the display element.
[2] The projection device according to [1], wherein the laser diodes of the plurality of laser diodes are arranged in parallel to each other.
[3] The light beam emitted to the image forming surface of the display element includes a light beam emitted from a fluorescent light emitter having excitation light emitted from the laser diode as excitation light. 1] or the projection apparatus according to [2].
[4] On the optical path from the light source to the display element, a reflection mirror that is formed in a rectangular shape and reflects the light emitted from the laser diode is disposed, and the laser diode has an elliptical cross section of the emitted light. The projection device according to any one of [1] to [3], wherein the laser diodes are oriented so that a major axis of the laser diode is substantially parallel to a long side of the reflecting mirror. .
[5] A member to which the reflection mirror is fixed and a holder to which a plurality of the laser diodes are fixed, and the member and the holder so that the member and the holder overlap each other when viewed from the upper surface of the housing. Are arranged. The projection apparatus according to [4], wherein:
[6] The laser diode is emitted from the upper surface of the housing toward the lower surface, and the reflection mirror is disposed on the lower surface so as to face the laser diode so as to reflect the emitted light from the laser diode. The projection apparatus according to [4] or [5] above, wherein
[7] The projection apparatus according to any one of [1] to [6], wherein the laser diode is cooled by a heat pipe.

DESCRIPTION OF SYMBOLS 10 Projector 11 Top panel 12 Front panel 13 Rear panel 14 Right panel 15 Left panel 17 Exhaust hole 18 Intake hole 19 Lens cover 20 Various terminals 21 Input / output connector part
22 I / O interface 23 Image conversion unit 24 Display encoder 26 Display drive unit 31 Image compression / decompression unit 32 Memory card 35 Reception unit 36 Processing unit 37 Key / indicator unit 38 Control unit 41 Light source control circuit 43 Cooling fan drive control circuit 45 Lens motor 47 Audio processing unit 48 Speaker 51 Display element 51a Image forming surface 51a1 Long side 51a2 Short side 51b Micro mirror 60 Light source unit 70 Blue light source device 71 Blue laser diode 75 Reflective mirror 80 Green light source device 81 Heat pipe 82 Cooling fin 83 Holder 100 Fluorescence Wheel device 101 Fluorescent wheel 107 Condensing lens group 110 Wheel motor 115 Condensing lens 120 Red light source device 121 Red light source 125 Condensing lens group 130 Heat sink 140 Light source side optical system 141 One dichroic mirror 143 First reflecting mirror 145 Second reflecting mirror 148 Second dichroic mirror 160 Optical system unit 161 Illumination side block 165 Image generation block 168 Projection side block 170 Light guiding optical system 173 Condensing lens 175 Light tunnel 178 Condensing lens 181 Optical axis conversion mirror 183 Condensing lens 185 Irradiation mirror 190 Heat sink 195 Condenser lens 220 Projection side optical system 225 Fixed lens group 235 Movable lens group 241 Control circuit board 261 Cooling fan

Claims (7)

A light source provided with a plurality of laser diodes;
A display element that irradiates the image forming surface formed with a light beam from the light source in a rectangular shape;
Have
Projection light characterized in that light emitted from the laser diode is incident on the display element such that the long axis of the cross sectional ellipse of the light emission is substantially parallel to the long side of the image forming surface of the display element. apparatus.   The projection device according to claim 1, wherein the laser diodes of the plurality of laser diodes are arranged in parallel to each other.   The light beam emitted to the image forming surface of the display element includes a light beam emitted from a fluorescent light emitter having excitation light emitted from the laser diode as excitation light. Item 3. The projection device according to Item 2.   On the optical path from the light source to the display element, a reflection mirror that is formed in a rectangular shape and reflects light emitted from the laser diode is disposed, and the laser diode has a long axis in a cross-sectional elliptical shape of the light emitted. 4. The projection apparatus according to claim 1, wherein the laser diodes are aligned so as to be substantially parallel to a long side of the reflection mirror. 5. A member to which the reflection mirror is fixed;
A holder to which a plurality of the laser diodes are fixed;
Have
The projection apparatus according to claim 4, wherein the member and the holder are arranged so that the member and the holder overlap each other when viewed from the upper surface of the housing.   The laser diode is emitted from the upper surface of the housing toward the lower surface, and the reflection mirror is disposed on the lower surface so as to face the laser diode so as to reflect the emitted light from the laser diode. The projection apparatus according to claim 4 or 5.   The projection apparatus according to claim 1, wherein the laser diode is cooled by a heat pipe.

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