JP2009276577A - Light guide device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide device capable of maintaining a small spoke angle, even if the color wheel is made small; and to provide a projector equipped with the light guide device, which can project images of high color brightness. <P>SOLUTION: The projector includes a light source device, the color wheel 68, the light guide device 75, a display element, a projection-side optical system, and a projector control means. The light guide device 75 includes a light incident port surrounded by two oblique lines whose extension lines cross each other at one prescribed point and two parallel lines crossing the two oblique lines, and formed of the oblique side portions formed by the two oblique lines and the parallel side portions formed by the two long and short straight lines. The light incident port is formed of an opening 72a of a light-shielding mask 72, and the light guide device is incorporated in the projector so that the intersection of the two extension lines of the oblique side portions may be located at the position of the rotational center axis of the color wheel 68. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light guide device and a projector including the light guide device.

  2. Description of the Related Art Today, data projectors that project an image displayed on a personal computer screen, an image of a video signal, an image based on image data stored in a memory card or the like onto a screen are widely used.

  In many cases, a data projector uses a light source device having a small high-intensity discharge lamp such as a metal halide lamp or an ultra-high pressure mercury lamp, and the light emitted from the light source device is converted into light of three primary colors by a color filter of a color wheel. Projection-side optical system having a zoom function by irradiating a display element called a liquid crystal or DMD (digital micromirror device) with a light source-side optical system equipped with a light guide device and the like, and transmitting or reflecting light from the display element The lens is projected onto a screen through a lens group.

The light guide device of the light source side optical system equalizes the intensity of the light flux that has passed through the color wheel, and is on the optical axis of the light emitted from the light source device, and the light guide surface and the light guide of the color wheel. A light tunnel or a rectangular parallelepiped shaped glass rod formed by fixing the ridges of four mirror plates with the inner surface as a reflecting surface with an adhesive is used. It is what Various proposals have been made regarding this light guide device, and the shape of the entrance and exit is a horizontally long rectangle that matches the shape of the display element (for example, Patent Document 1).
JP 2007-65148 A

  Since recent projectors have been reduced in size and thickness, it is necessary to make various devices housed in the projector small, and it is also necessary to reduce the disk-shaped color wheel. However, when the color wheel is formed small in accordance with the shape of the entrance of the light guide device, there is a problem that the spoke angle becomes large because the shape of the entrance of the light guide device is rectangular.

  Here, the term “spoke” refers to a region where the color boundary crosses the light bundle when the color wheel is rotating, and the spoke light that is transmitted through the spoke has two colors. Since they are mixed, they cannot be used for projection by a projector. The spoke angle is the angle from the start of the color wheel color boundary to the light bundle until the end of the light beam. The spoke angle in relation to the light guide device is the light guide of the color wheel color guide. This means the angle from the start of the application to the end of the application. In the following description, the angle from the start of the color wheel color boundary to the application of the light guide to the end of the application is called the spoke angle. .

  The spoke angle is determined by the shape of the color wheel and the entrance of the light guide device.When the spoke angle increases, the area of monochromatic light that can be used for each rotation of the color wheel decreases, and the brightness of the projected image There is a problem that falls.

  The present invention has been made in view of the above-described problems of the prior art, and includes a light guide device that can keep the spoke angle small even if the color wheel is small, and the light guide device including the light guide device. An object of the present invention is to provide a projector capable of projecting a high image.

  The light guide device of the present invention is surrounded by two oblique lines where extension lines intersect each other at a predetermined point and two parallel straight lines intersecting the two oblique lines, and is formed by at least the two oblique lines The incident port is formed by the oblique side portion and the parallel side portion formed by two long and short straight lines formed by the parallel straight lines.

  The entrance is formed by an opening of a light shielding mask.

  Furthermore, the incident port has an isosceles trapezoidal shape surrounded by the oblique side portion and the parallel side portion.

  Further, the parallel side portion is a long side portion and a short side portion, and the entrance is a hexagon having a straight portion between both ends of the long side portion of the parallel side portion and the oblique side portion, The straight line portion is formed by two straight lines that are orthogonal to the long side portion and connect the long side portion and the oblique side portion.

  Further, in the incident port, the straight portions have the same length and the oblique sides have the same length.

  The light guide device according to any one of claims 1 to 5, further comprising a light tunnel having an internal space whose cross section is a horizontally long rectangular shape.

  In some cases, a light tunnel having an internal space whose cross section has the same shape as the entrance is provided.

  The projector according to the present invention includes a light source device, a color wheel, a light guide device, a display element, and a projection-side optical system, and includes projector control means. It is supposed to be an optical device.

  The light guide device is incorporated in the projector so that a predetermined point where the extension lines of the oblique sides intersect is located at the position of the rotation center axis of the color wheel.

  According to the present invention, it is an object to provide a light guide device that can keep a spoke angle small even if the color wheel is small, and a projector that includes the light guide device and can project an image with high brightness. .

  The projector 10 according to the best mode for carrying out the present invention includes a light source device 63, a color wheel 68, a light guide device 75, a display element 51, and a projection-side optical system 90, and includes projector control means. Is.

  The light guide device 75 is surrounded by two oblique lines where the extension lines intersect each other at a predetermined point and two parallel straight lines intersecting the two oblique lines, and at least by the two oblique lines. It has an incident port formed by the oblique side portion formed and the parallel side portion formed by two long and short straight lines formed by the parallel straight lines.

  The entrance is formed by the opening 72a of the light shielding mask 72 and has an isosceles trapezoidal shape surrounded by the oblique side portion and the parallel side portion.

  The light guide device 75 is incorporated in the projector 10 so that a predetermined point where the extension lines of the oblique sides intersect is located at the position of the rotation center axis of the color wheel 68.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the projector 10 according to the embodiment of the present invention has a substantially rectangular parallelepiped shape, and includes a lens cover 19 that covers a projection port on a side of a front panel 12 that is a side plate in front of the main body case. At the same time, the front panel 12 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.

  The top panel 11 as a main body case is provided with a key / indicator section 37. The key / indicator section 37 includes a power switch key, a power indicator for notifying power on / off, projection on, A projection switch key for switching off, a key and an indicator such as an overheat indicator for notifying when a light source device, a display element or a control circuit is overheated are provided.

  Further, on the back surface 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 inputting image signals, an S terminal, an RCA terminal and the like on the rear panel. Is.

  A plurality of air intake holes 18 are provided in 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.

  As shown in FIG. 2, the projector control means of the projector 10 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 image signals of various standards input from the connector unit 21 are converted so as to be unified into an image signal of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB). Thereafter, it is sent to the display encoder 24.

  The display encoder 24 develops and stores the transmitted 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.

  A display drive unit 26 to which a video signal is input from the display encoder 24 drives a display element 51 which is a spatial light modulation element (SOM) at an appropriate frame rate in accordance with the transmitted image signal. A projection system lens that forms a light image with the reflected light of the display element 51 and makes the light beam emitted from the light source device 63 incident on the display element 51 via the light source side optical system, and serves as a projection side optical system An image is projected and displayed through a group on a screen (not shown). The movable lens group 97 of the projection side optical system is driven by a lens motor 45 for zoom adjustment and focus adjustment.

  In addition, the image compression / decompression unit 31 performs a recording process for sequentially writing a luminance signal and a color difference signal of an image signal to a memory card 32 that is a removable recording medium by performing data compression by processing such as ADTC and Huffman coding. In the mode, the image data recorded on the memory card 32 is read, and individual image data constituting a series of moving images is expanded in units of one frame and sent to the display encoder 24 via the image conversion unit 23. A moving image or the like can be displayed based on the stored image data.

  The control unit 38 controls the 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. ing.

  In addition, the operation signal of the key / indicator unit 37 composed of the main key and the indicator provided on the upper panel 11 of the main body case is directly sent to the control unit 38, and the 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 sent to the control unit 38.

  An audio processing unit 47 is connected to the control unit 38 via a system bus (SB). The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and converts the audio data into analog data in the projection mode and the playback mode. The speaker 48 can be driven to emit loud sounds.

  The control unit 38 controls the power supply control circuit 41. The power supply control circuit 41 turns on the discharge lamp of the light source device 63 when the lamp switch key is operated. Further, the cooling fan drive control circuit 43 performs temperature detection by a plurality of temperature sensors provided in the light source device 63, etc., and controls the rotation speed of the cooling fan. In addition, the rotation of the cooling fan is continued, and control such as turning off the power of the projector main body is performed depending on the result of temperature detection by the temperature sensor.

  These ROM, RAM, IC and circuit elements are incorporated in the control circuit board 103 and the power supply circuit block 101 as the main control board shown in FIG. The light source control circuit board 102 to which the system power supply circuit block 101 and the like are attached is formed separately.

  As shown in FIG. 3, the projector 10 has an internal structure in which a light source control circuit board 102 to which a power supply circuit block 101 and the like are attached is disposed in the vicinity of the right panel 14, and the interior of the housing is separated by a partition wall 120. The air intake side space chamber 121 on the side and the exhaust side space chamber 122 on the front panel 12 side are airtightly partitioned. Then, a sirocco fan type blower 110 as a cooling fan is arranged so that the suction port 111 is located in the intake side space chamber 121 and the discharge port 113 is located at the boundary between the exhaust side space chamber 122 and the intake side space chamber 121. It is what.

  Further, in the exhaust-side space chamber 122, a light source device 63 having a reflector in which the upper and lower sides of an elliptical spherical shape are cut into a planar shape, and a discharge lamp using halogen or the like built in the reflector, and a light source A first reflecting mirror 67 that converts the optical axis direction of light emitted from the device 63, a color wheel 68 that is provided with red, green, and blue color filters and is rotated by a wheel motor, a cooling fin, and a heat pipe. Further, an exhaust temperature reducing device 114 is disposed.

  The optical system unit 65 includes three blocks: an illumination side block located in the vicinity of the light source device 63, an image generation block including the display element 51, and a projection side block including the projection side optical system 90. And is arranged along the left panel 15.

  The illumination side block includes a part of the light source side optical system that guides the light emitted from the light source device 63 and colored by the color wheel 68 to the display element 51 included in the image generation block. As a system, a light guide device 75 including a light tunnel 71 and a light shielding mask 72 that use light transmitted through a filter of the color wheel 68 as a light beam having a uniform intensity distribution, and a light bundle emitted from the light guide device 75 are collected. There is a light collecting lens.

  The color wheel 68 includes fan-shaped color filters arranged side by side in the circumferential direction. The color wheel 68 colors the light emitted from the light source device 63 and emits the colored light to the light guide device 75. Here, in the color wheel 68, when the color wheel 68 is rotating, the area where the color boundary crosses the light bundle is called the spoke, and the spoke that is the light transmitted through the spoke. Since light is a mixture of two colors, it cannot be used for projection by a projector. Therefore, the angle from when the color boundary of the color wheel 68 starts to be applied to the light guide device 75 to when it is applied is called the spoke angle.

  As shown in FIG. 4, the light guide device 75 in this embodiment includes a hollow cuboid light tunnel 71 having an inner surface as a reflection surface, and a trapezoidal opening 72a and an incident side end surface 71f of the light tunnel 71. And a light-shielding mask 72 disposed so as to be close to each other.

  This light tunnel 71 has four rectangular mirror plates, one of which is a reflection surface, and is formed into a hollow rectangular parallelepiped shape by bonding and fixing the ridges in the longitudinal direction of these mirror plates. It has a space, has an inner surface as a reflection surface, and has a horizontally-long rectangular incident side end surface 71f and an emission side end surface.

  The light shielding mask 72 is a rectangular plate that forms the entrance of the light guide device 75, and has an opening 72a that is an isosceles trapezoid entrance. Light which is arranged close to 71f and becomes effective light close to the optical axis in the light bundle emitted from the light source device 63 described above and transmitted through the color wheel 68 enters the light tunnel 71 and becomes unnecessary light. It blocks spoke light and diffused light.

  Then, the opening 72a of the light shielding mask 72, which is the entrance of the light guide device 75, includes two oblique lines whose extension lines intersect each other at a predetermined point, and two long and short parallel straight lines that intersect the two oblique lines. The part formed by two diagonal lines is the oblique side part, and the part formed by the long side part and the short side part which are two long and short straight lines by the parallel straight line is the parallel side part. The predetermined one point where the two oblique lines forming the oblique side intersect is formed so as to be located at the rotation center axis position of the color wheel 68.

  That is, the oblique side portion of the opening 72a in the light shielding mask 72 starts to be applied to the center point of the incident side end face 71f of the upper and lower mirror plates of the light tunnel 71 when the color wheel 68 rotates. It is formed from the oblique line formed at the position and the oblique line formed at the position where the engagement ends.

  The light shielding mask 72 is disposed in the vicinity of the incident side end face 71f of the light tunnel 71, so that a part of the oblique side blocks a part of the incident side end face 71f of the light tunnel 71. The spoke angle is reduced by shielding a part of the circular light bundle emitted from 63 and transmitted through the color wheel 68 away from the optical axis.

  Then, as shown in FIG. 3, the image generation block changes the direction of the light emitted from the light tunnel 71 and the light reflected by the second reflection mirror 70 to the display element 51. A light source side lens group 83 formed by a plurality of condensing lenses, and an irradiation mirror 84 that irradiates the display element 51 with light transmitted through the light source side lens group 83 at a predetermined angle as a light source side optical system. A DMD (digital micromirror device) serving as a display element 51 is provided. 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 to prevent the display element 51 from becoming high temperature.

  The projection-side block has 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. As the projection-side optical system 90, a fixed lens built in a fixed barrel This is a variable focus lens with a zoom function with the group 93 and the movable lens group 97 built in the movable lens barrel. Zoom and focus adjustments are possible by moving the movable lens group 97 with a lens motor. It is what you are trying.

  The light guide device 75 in the present embodiment has a light shielding mask 72 disposed close to the incident side end surface 71f of the rectangular parallelepiped light tunnel 71, but when this light shielding mask 72 is not disposed, the spoke angle is As shown in FIG. 5, the angle θ ′ is determined by a straight line drawn from above the rotation center axis of the color wheel 68 to the top and bottom of the mirror surface located on the rotation center axis side of the color wheel 68 in the light tunnel 71. However, in the light guide device 75 of the present embodiment, since the light shielding mask 72 having the isosceles trapezoidal opening 72a is disposed close to the incident side end face 71f of the light tunnel 71, the spoke angle is the color wheel 68. The angle θ is determined by a straight line drawn from the center axis of rotation to the center of the incident side end face 71f of the upper and lower mirror plates of the light tunnel 71. Therefore, since the spoke angle is reduced by the angle derived by θ′−θ, the light that becomes effective light among the light transmitted through the color filter of the color wheel increases, thereby increasing the amount of monochromatic light. Therefore, the projector 10 capable of projecting an image with high brightness can be provided.

  Further, as described above, the light shielding mask 72 shields a part of the circular light bundle emitted from the light source device 63 and transmitted through the color wheel 68 away from the optical axis, but transmitted through the color wheel 68. Since the density of the light bundle does not decrease as it moves away from the optical axis, even if the position away from the optical axis is shielded, the amount of light is not greatly reduced, and the amount of light increased by efficiently shielding the spoke light is better. growing.

  Further, in recent projectors 10, the color wheel 68 needs to be miniaturized in order to reduce the size and thickness, but when the color wheel 68 is miniaturized, the light guide device 75 starts from the center of the color wheel 68. However, there is a problem that the spoke angle is increased because the distance to the entrance is increased, but by using the light guide device 75 in this embodiment, the spoke angle can be kept small, and the amount of light is kept. The color wheel 68 can be downsized, and thus the projector 10 can be reduced in size and thickness.

  As shown in FIG. 6, even when the light tunnel 71 is inclined with respect to the radial direction of the color wheel 68, the short side of the parallel side portion at the entrance surrounded by the oblique side portion and the parallel side portion. By making the inclination of the part and the long side part the same as the inclination of the light tunnel 71, that is, by forming a trapezoidal entrance where the inclination of the side surface of the light tunnel and the inclination of the short side part and the long side part are the same, It is possible to provide the light guide device 75 that can obtain the same effect as the above-described embodiment.

  Furthermore, a modified example of the present invention will be described. As shown in FIGS. 7 and 8, the opening 72 a of the light shielding mask 72 serving as the entrance in this modification has six linear portions between the opposite sides of the long side portion forming the parallel side portion and the oblique side portion. The straight part is formed by two straight lines that are orthogonal to the long side part of the parallel side part and connect between the long side part and the oblique side part. And the lengths of the oblique sides are equal. In other words, by making the mutual length of the straight line part and the mutual length of the oblique side part equal, the entrance is symmetrical with respect to the center line connecting the short side part of the parallel side part and the midpoint of the long side part. It is supposed to be a shape.

  According to this modification, the opening 72a of the light shielding mask 72 is hexagonal, so that the spoke angle θ can be kept small as in the above-described embodiment, and the light beam transmitted through the color wheel 68 is reflected by the light tunnel. Since it can prevent the diffused light generated by irradiating the edge surface located on the incident side end face 71f of the mirror plate of 71 from entering the light tunnel 71, it can project a clear and light image. is there.

  In the case where the shape of the entrance is hexagonal as described above, when the light tunnel 71 is arranged to be inclined with respect to the radial direction of the color wheel 68, as shown in FIG. By forming the same as the inclination of the light tunnel 71, the same effect can be obtained.

  As still another modification, as shown in FIGS. 10 and 11, the light tunnel 71 has an incident side end face 71f and an emission side end face having the same shape as the opening 72a of the light shielding mask 72, that is, The cross-sectional shape of the light tunnel 71 may be formed in the same shape as the opening 72a of the light shielding mask 72. By forming the cross-sectional shape of the light tunnel 71 in the same shape as the opening 72a of the light shielding mask 72 in this way, the light bundle deformed by the light shielding mask 72 can be made uniform while maintaining the deformed shape. Therefore, the intensity of the light flux emitted from the emission side end face of the light tunnel 71 is stabilized, and therefore, it is possible to provide the projector 10 capable of projecting an image without luminance unevenness and lightness unevenness.

  Furthermore, in the above-described embodiments and modifications, the light guide device 75 is formed from the light tunnel 71 and the light shielding mask 72, but the light guide device 75 can also be formed from the glass rod and the light shielding mask 72. Even in the case, the same effect can be obtained.

  As described above, the light shielding mask 72 provided with the opening 72a having two oblique sides where the extension line intersects at a predetermined point on the incident side end surface 71f of the light tunnel 71 or the glass rod is disposed close to the two. By using the light guide device 75 having the exit having the oblique sides, the spoke angle by the color wheel 68 can be reduced by the oblique sides, and the extended intersection of both oblique sides is the position of the rotation center axis of the color wheel 68. , The spoke angle can be minimized.

  In addition, when the shape of the entrance is an isosceles trapezoidal shape, and a hexagonal shape with a rectangle added to the base of the isosceles trapezoid, the guide is combined with the color wheel 68 in accordance with the interior shape of the projector 10. By reducing the size of the light device 75 and reducing the amount of light incident on the light guide device 75, the spoke angle is reduced and the incident time of the primary color light transmitted through the color wheel 68 rotating at a constant speed is increased. The amount of light transmitted through the light guide device 75 can be increased.

  When the light tunnel 71 and the glass rod are formed in a rectangular parallelepiped shape as in the prior art to form a rectangular parallelepiped light guide path, the spoke angle can be easily reduced by simply forming the opening 72a of the light shielding mask 72 into a trapezoidal shape or the like. The light guide device 75 can be manufactured, but the light guide device 75 can reduce the spoke angle by using a light tunnel 71 or a glass rod having a light guide path having a trapezoidal cross section. It can be done.

  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.

1 is a perspective view showing an external appearance of a projector according to an embodiment of the invention. FIG. 3 is a diagram illustrating a functional circuit block of the projector according to the embodiment of the invention. FIG. 3 is a top view of the projector according to the embodiment of the present invention with the top panel removed. The perspective view of the light guide device which concerns on the Example of this invention. The front view which looked at the light guide device and color wheel which concern on the Example of this invention from the incident side. The front view which looked at the light guide apparatus and color wheel from the incident side at the time of arranging the light tunnel inclining with respect to the radius of a color wheel in the Example of this invention. The perspective view of the light guide device which concerns on the modification of this invention. The front view which looked at the light guide device and color wheel which concern on the modification of this invention from the incident side. The front view which looked at the light guide apparatus and color wheel from the incident side at the time of arrange | positioning a light tunnel inclining with respect to the radius of a color wheel in the modification of this invention. The perspective view of the light guide device which concerns on the other modification of this invention. The front view which looked at the light guide device and color wheel which concern on the other modification of this invention from the incident side.

Explanation of symbols

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 Power supply control circuit 43 Cooling fan drive control circuit
45 Lens motor 47 Audio processor
48 Speaker 51 Display element
53 Display element cooling device 63 Light source device
65 Optical system unit 67 First reflection mirror
68 Color wheel 70 Second reflection mirror
71 Light tunnel 71f Incident side end face
72 Opening mask 72a Opening
75 Light guide device 83 Light source side lens group
84 Irradiation mirror 90 Projection side optical system
93 Fixed lens group 97 Movable lens group
101 Power circuit block 102 Power control circuit board
103 Control circuit board 110 Blower
111 Suction port 113 Discharge port
114 Exhaust temperature reduction device 120 Partition wall
121 Inlet side space 122 Exhaust side space

Claims (9)

  The extension line is surrounded by two oblique lines intersecting each other at a predetermined point and two parallel straight lines intersecting the two oblique lines, and at least a hypotenuse formed by the two oblique lines, and the parallel A light guide device having an entrance opening with parallel sides formed by two straight and long straight lines.   The light guide device according to claim 1, wherein the incident port is formed by an opening of a light shielding mask.   The light guide device according to claim 1, wherein the entrance has an isosceles trapezoidal shape surrounded by the oblique side and the parallel side.   The parallel side portion is a long side portion and a short side portion, and the incident port is a hexagon having a straight portion between both ends of the long side portion of the parallel side portion and the oblique side portion, and the straight portion The light guide device according to claim 1, wherein the light guide device is formed by two straight lines that are orthogonal to the long side portion and connect the long side portion and the oblique side portion. .   5. The light guide device according to claim 4, wherein the incident ports have the same length of the straight line portions and the same length of the oblique sides.   The light guide device according to any one of claims 1 to 5, further comprising a light tunnel having an internal space having a horizontally long cross section.   The light guide device according to claim 1, further comprising a light tunnel having an internal space whose cross section has the same shape as the incident port. A light source device, a color wheel, a light guide device, a display element, and a projection-side optical system, provided with a projector control means;
The projector according to claim 1, wherein the light guide device is a light guide device according to claim 1.   9. The projector according to claim 8, wherein the light guide device is incorporated in the projector so that a predetermined point where the extension lines of the oblique sides intersect is located at the position of the rotation center axis of the color wheel. .

Images