JP2006106381A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector without lowering light utilization efficiency and increasing a light stray level, even when providing a reflection optical system for reflecting a part of light from a emission tube on a light source device toward an elliptical face reflector in the projector provided with a micro mirror modulator. <P>SOLUTION: The projector 1000A comprises a lighting system 100A provided with a light source device 110A and an integrator rod 120A, a relay optical system 140, the micro mirror modulator 200, and a projection optical system 300. The integrator rod 120A comprises a solid glass rod of an inner face entire reflection type. The emission tube 112 attaches an auxiliary mirror 116A reflecting light radiated from the emission tube to the side of the region to be illuminated toward the elliptical face reflector 114A. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector.

  FIG. 10 is a view for explaining a projector 1000a provided with a conventional micromirror type modulation device. FIG. 10A is a diagram showing an optical system of a projector 1000a provided with a conventional micromirror type modulation device, and FIG. 10B shows a light source device 110a in the projector 1000a provided with a conventional micromirror type modulation device. FIG.

  As shown in FIG. 10A, a projector 1000a having a conventional micromirror type modulation device converts light from the light source device 110a that emits focused light and light from the light source device 110a into light having a more uniform intensity distribution. An illumination device 100a having an integrator rod 120a, a relay optical system 140a that guides light from the illumination device 100a to an illuminated area, and a micromirror-type modulation device 200a that modulates light from the relay optical system 140a according to image information. And a projection optical system 300a for projecting light modulated by the micromirror type modulation device 200a. A color wheel 130a is provided on the light incident surface side of the integrator rod 120a.

  As shown in FIG. 10B, the light source device 110a includes an ellipsoidal reflector 114a and an arc tube 112a having a light emission center in the vicinity of the first focal point of the ellipsoidal reflector 114a, and a converging beam emitted from the ellipsoidal reflector 114a. It further includes a reflective optical system 160 that allows light in the central portion of the light to pass and reflects the light in the peripheral portion to return the light in the peripheral portion in the direction opposite to the incident direction.

  For this reason, according to the projector 1000a provided with the conventional micromirror type modulation device, the angle of the focused light emitted from the light source device 110a can be reduced by the action of the reflection optical system 160. The incident angle of the incident focused light can be reduced, and the utilization efficiency of the illumination light in the illumination device can be easily improved (for example, see Patent Document 1).

  However, in the projector 1000a provided with the conventional micromirror type modulation device, the reflective optical system 160 needs to reflect the peripheral light of the focused light emitted from the elliptical reflector 114a. There is a problem that it is necessary to have the same size as 114a, and the light source device becomes large. As a result, the opening of the ellipsoidal reflector 114a is blocked by the large reflective optical system 160, which causes a problem that the cooling efficiency of the light source device is lowered.

In order to simplify the structure of the light source device and prevent the cooling efficiency of the light source device from decreasing in the projector 1000a having the conventional micromirror type modulation device, instead of the reflective optical system 160, FIG. It is conceivable to use a reflection optical system 170 as shown in FIG. FIG. 11 shows another conventional light source device 110b.
As shown in FIG. 11, another conventional light source device 110b includes an ellipsoidal reflector 114b and an arc tube 112b having a light emission center in the vicinity of the first focal point of the ellipsoidal reflector 114b, and an illuminated area from the ellipsoidal reflector 114b. It further has a reflection optical system 170 that reflects the light emitted to the side toward the ellipsoidal reflector 114b. The reflection optical system 170 is made of a reflection film formed on the outer surface of the bulb of the arc tube 112b.

  For this reason, if another conventional light source device 110b is used, the reflection optical system 170 causes the light emitted from the ellipsoidal reflector 114b to the illuminated area side by the reflection film formed on the outer surface of the tube of the arc tube 112b. Since the light is reflected, the light source device can be simplified. Moreover, this does not reduce the cooling efficiency of the light source device (see, for example, Patent Document 2).

JP 2003-222820 A International Publication No. 03/033959 Pamphlet

  However, according to the analysis of the present inventor, in the arc tubes currently in circulation, for each arc tube, the shape and size of the bulb, the position of the electrode, the position of the emission center, etc. cannot be ignored. It was found that there was variation. Therefore, in the projector 1000a provided with the conventional micromirror type modulation device as described above, when the reflection optical system 170 in another conventional light source device 110b is used instead of the reflection optical system 160, it is surely. The light source device can be simplified and the cooling efficiency of the light source device is not reduced. On the other hand, the light reflected by the reflective optical system 170 toward the ellipsoidal reflector is not necessarily the light emitting portion of the arc tube. Will not pass. As a result, when such light is reflected by the ellipsoidal reflector, there is a problem in that the light does not reach the light incident surface of the integrator rod, and the light use efficiency is lowered and the stray light level is increased.

  The present invention has been made to solve such a problem, and in a projector having a micromirror type modulation device, the light source device reflects a part of the light from the arc tube toward the ellipsoidal reflector. It is an object of the present invention to provide a projector in which the light use efficiency does not decrease and the stray light level does not increase even when a reflective optical system is provided.

  The projector of the present invention includes a light source device having an ellipsoidal reflector and an arc tube having a light emission center in the vicinity of a first focal point of the elliptical reflector, and a light incident surface in the vicinity of a second focal point of the elliptical reflector. An illumination device including an integrator rod that converts light from the illumination device into light having a more uniform intensity distribution, a relay optical system that guides the light from the illumination device to an illuminated area, and an image of the light from the relay optical system In the projector including a micromirror type modulation device that modulates according to information and a projection optical system that projects light modulated by the micromirror type modulation device, the integrator rod is a solid glass with internal total reflection type It is composed of a rod, and the arc tube reflects light emitted from the arc tube toward the illuminated area toward the ellipsoidal reflector. Wherein the auxiliary mirror is attached.

  For this reason, according to the projector of the present invention, since the auxiliary mirror as the reflection optical system is attached to the arc tube, the angle of the focused light emitted from the light source device can be reduced. For this reason, the incident angle of the focused light incident on the integrator rod can be reduced, and the utilization efficiency of the illumination light in the illumination device can be easily improved.

  Further, according to the projector of the present invention, since the auxiliary mirror as the reflection optical system described above is attached to the arc tube, the shape and size of the tube, the electrode arrangement position, the emission center are provided for each arc tube. Even if there is a variation that cannot be ignored, the above-described variation can be absorbed by adjusting the mounting position of the auxiliary mirror with respect to the arc tube in accordance with the variation. As a result, the projector of the present invention is a projector provided with a micromirror type modulation device, in which the light source device is provided with a reflective optical system that reflects part of the light from the arc tube toward the ellipsoidal reflector. However, the projector does not decrease the light utilization efficiency or increase the stray light level.

  Further, according to the projector of the present invention, the integrator rod is made of a solid glass rod with total internal reflection, so that the light incident on the integrator rod travels toward the light exit surface while being totally reflected by the inner surface of the integrator rod. To do. For this reason, since the reflection loss inside the integrator rod is eliminated, the light utilization efficiency is improved.

  In the projector according to the aspect of the invention, it is preferable that the auxiliary mirror is fixed to the arc tube after position adjustment with respect to the arc tube.

  With this configuration, the auxiliary mirror is fixed to the arc tube after adjusting the mounting position of the auxiliary mirror with respect to the arc tube and adjusting the above-described variation. The light emitted from the tube toward the illuminated area is always reflected correctly toward the light emitting portion of the arc tube. Thereafter, the light passing through the light emitting portion of the arc tube is reflected by the ellipsoidal reflector and correctly reaches the light incident surface of the integrator rod, so that the light use efficiency does not decrease and the stray light level does not increase.

  In the projector according to the aspect of the invention, it is preferable that the auxiliary mirror is fixed to a sealing portion on the opposite side of the elliptical reflector in the arc tube.

  With this configuration, it is possible to easily adjust the position of the auxiliary mirror with respect to the arc tube and then fix the auxiliary mirror to the arc tube.

  In the projector according to the aspect of the invention, it is preferable that the auxiliary mirror is made of quartz glass.

In the projector according to the present invention, the auxiliary mirror is disposed very close to the arc tube, and thus is placed in an extremely high temperature environment. However, when the auxiliary mirror is made of quartz glass having a low thermal expansion coefficient and excellent heat resistance as in the projector of the present invention, deterioration of optical characteristics due to heat is suppressed.

  In the projector according to the aspect of the invention, it is preferable that a reflection film made of a dielectric multilayer film is formed on the inner surface of the auxiliary mirror.

  As described above, in the projector according to the present invention, the auxiliary mirror is disposed very close to the arc tube, and thus is placed in an extremely high temperature environment. However, when the reflective film is formed of a dielectric multilayer film having a low thermal expansion coefficient and excellent heat resistance as in the projector of the present invention, the deterioration of the reflection characteristics due to heat can be suppressed.

  In the projector of the present invention, it is preferable that the reflective film of the auxiliary mirror is an infrared transmissive reflective film. By configuring in this way, the infrared rays emitted from the arc tube and reaching the auxiliary mirror pass through the auxiliary mirror as they are, so that the temperature rise of the auxiliary mirror is suppressed.

From these viewpoints, it is preferable to use a dielectric multilayer film composed of SiO ₂ as a low refractive dielectric and TiO ₂ and / or Ta ₂ O ₅ as a high refractive index dielectric as the dielectric multilayer film. .

In the projector according to the aspect of the invention, it is preferable that the relationship of 6 mm ≦ f ₁ ≦ 18 mm is satisfied, where f ₁ is the first focal length of the ellipsoidal reflector.

That is, when the first focal length f ₁ of the ellipsoidal reflector is less than 6 mm, the distance between the light emission center of the arc tube and the base of the ellipsoidal reflector becomes too short, and the bulb portion of the arc tube (usually having a diameter of 6 mm). And the base of the ellipsoidal reflector may come into contact with each other.
On the other hand, when the first focal length f ₁ of the ellipsoidal reflector exceeds 18 mm, it is necessary to use a large ellipsoidal reflector having a large effective reflecting surface diameter in order to secure the amount of light trapped from the arc tube. End up. As a result, it is not easy to reduce the size of the lighting device.
From this point of view, it is more preferable to satisfy the relationship of 9 mm ≦ f ₁ ≦ 15 mm.

In the projector according to the aspect of the invention, it is preferable that the relationship of 30 mm ≦ f ₂ ≦ 90 mm is satisfied, where f ₂ is the second focal length of the ellipsoidal reflector.

That is, when the second focal length f ₂ of the ellipsoidal reflector is less than 30 mm, the tip of the illuminated region side of the lead portion of the arc tube (usually away 20mm~35mm from the light emission center of the light emitting tube.) And the integrator rod There is a possibility of contact with the light incident surface.
On the other hand, when the second focal length f ₂ of the ellipsoidal reflector is more than 90 mm, would occur is necessary to lengthen the first focal length f ₁ of the ellipsoidal reflector, Sonaruto, to ensure the swallowing amount of light from the arc tube Therefore, it becomes necessary to use a large elliptical reflector having a large effective reflecting surface diameter. As a result, it is not easy to reduce the size of the lighting device.

In the projector of the present invention, it is more preferable to satisfy the relationship of f ₂ ≦ 75 mm.

In the projector according to the present invention, as described above, the integrator rod is formed of a solid glass rod with total internal reflection, so that there is no reflection loss inside the integrator rod, and light utilization efficiency is improved.
By the way, in the projector of the present invention, the light from the light source device is refracted at the light incident surface of the integrator rod, so that the light incident on the integrator rod travels toward the light exit surface at a shallower angle. For this reason, in order to implement | achieve sufficient light equalization effect in the solid glass rod of a total internal reflection type, it will be necessary to lengthen the length of an integrator rod.

However, according to the projector of the present invention, the second focal length f ₂ of the ellipsoidal reflector by a 75mm or less, that the incident angle at which incident from the light source device to the light incident surface of the integrator rod deeper it can. As a result, it is not necessary to increase the length of the integrator rod so as to achieve a sufficient light uniforming effect.
From this viewpoint, it is more preferable to satisfy the relationship of f ₂ ≦ 60 mm. By doing in this way, the length of an integrator rod can further be shortened, without enlarging the diameter of the effective reflective surface of an ellipsoidal reflector so much.
In the projector of the present invention, the light source device because it has an auxiliary mirror, also, increasing the diameter of the effective reflective surface of the ellipsoidal reflector as possible to shorten the second focal length f _2, as described above There is no need.

  In the projector according to the aspect of the invention, it is preferable that the relationship of 30 mm ≦ D ≦ 50 mm is satisfied, where D is the diameter of the effective reflection surface of the elliptical reflector.

That is, when the diameter D of the effective reflecting surface of the ellipsoidal reflector is less than 30 mm, there is a possibility that the area for reflecting light from the arc tube becomes too small and the amount of light guided to the integrator rod is insufficient.
On the other hand, if the diameter D of the effective reflecting surface of the ellipsoidal reflector exceeds 50 mm, the ellipsoidal reflector itself becomes too large and it is not easy to reduce the size of the lighting device.

  In the projector of the present invention, it is more preferable to satisfy the relationship of D ≧ 35 mm.

In the projector of the present invention, the integrator rod is composed of a solid glass rod with total internal reflection type, and as described above, in order to achieve a sufficient light uniformizing effect in the solid glass rod with total internal reflection type, It becomes necessary to make the length of the integrator rod longer.
However, according to the projector of the present invention, the light source device because it has a sub-mirror, as described above, the second focal length f ₂ is shortened without increasing the diameter of the effective reflective surface of the ellipsoidal reflector be able to. For this reason, by making the diameter D of the effective reflection surface of the ellipsoidal reflector at most 35 mm, the incident angle when entering the light incident surface of the integrator rod from the light source device can be made deeper. As a result, it is not necessary to increase the length of the integrator rod so as to achieve a sufficient light uniforming effect.
From this point of view, it is more preferable to satisfy the relationship of D ≧ 40 mm.

  In the projector according to the aspect of the invention, the maximum angle formed by the light beam emitted from the light emission center of the arc tube to the ellipsoidal reflector is defined as θ. It is preferable that the relationship of 90 ° ≦ θ ≦ 110 ° is satisfied.

That is, when the maximum angle θ is less than 90 °, there is a possibility that the reflection area of the ellipsoidal reflector that reflects light from the arc tube becomes too small and the amount of light guided to the integrator rod is insufficient.
On the other hand, when the maximum angle θ exceeds 110 °, the ellipsoidal reflector itself becomes too large, and it is not easy to reduce the size of the lighting device.
As described above, in the projector of the present invention, the ellipsoidal reflector is configured to be smaller than the conventional one. However, light emitted from the arc tube at an angle exceeding 110 ° is reflected by the auxiliary mirror and guided to the ellipsoidal reflector. Therefore, the light use efficiency is not lowered.

  In the projector according to the aspect of the invention, it is preferable that the projector further includes a color wheel disposed on the light exit surface side of the integrator rod.

In the projector of the present invention, the light exit surface of the integrator rod is at a position optically conjugate with the image forming region of the micromirror type modulator. The color wheel is arranged further on the illuminated area side than the light exit surface of the integrator rod. For this reason, the image on the image forming area of the micromirror type modulation device at the boundary of each color filter in the color wheel is somewhat blurred.
However, according to the projector of the present invention, since the angle of the focused light emitted from the light source device can be reduced, the incident angle of the focused light incident on the integrator rod can be reduced. As a result, the emission angle of the light emitted from the integrator rod can be reduced, the blurring of the image on the image forming area of the micromirror type modulator at the boundary of each color filter is reduced, and the color reproducibility is improved. To do.

  The projector of the present invention will be described below based on the embodiments shown in the drawings.

Embodiment 1
FIG. 1 is a diagram for explaining a projector 1000A according to the first embodiment. 1A is a view of the optical system of the projector 1000A as viewed from above, FIG. 1B is a view of the optical system of the projector 1000A as viewed from the side, and FIG. 1C is a view of the integrator rod 120A. FIG. 1 (d) is a view of the light incident surface along the illumination optical axis, FIG. 1 (d) is a view of the light exit surface of the integrator rod 120A along the illumination optical axis, and FIG. 1 (e) is a color wheel. FIG. 1F is a view of the illumination light beam Bw passing through the color wheel 130 along the illumination optical axis, and FIG. 1G is a micromirror. It is a figure which shows the illumination light beam irradiated to the type | mold modulation apparatus 200. FIG.

  In the following description, the three directions orthogonal to each other are defined as the z-axis direction (illumination optical axis 100Aax direction in FIG. 1A) and the x-axis direction (parallel to the paper surface in FIG. And a direction perpendicular to the paper surface in FIG. 1A and perpendicular to the z-axis.

  As shown in FIGS. 1A and 1B, the projector 1000A according to the first embodiment converts light from the light source device 110A that emits focused light and the light source device 110A into light having a more uniform intensity distribution. Illumination device 100A including integrator rod 120A for conversion, relay optical system 140 that guides light from illumination device 100A to an illuminated area, and micromirror modulation that modulates light from relay optical system 140 according to image information An apparatus 200 and a projection optical system 300 that projects light modulated by the micromirror type modulation apparatus 200 are provided.

  The light source device 110A will be described in detail later, but as shown in FIGS. 1A and 1B, the ellipsoidal reflector 114A and the arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114A. And have. The arc tube 112 is provided with an auxiliary mirror 116A as a reflection optical system that reflects the light emitted from the arc tube 112 toward the illuminated region toward the ellipsoidal reflector 114A. The light source device 110A emits focused light that is focused near the light incident surface of the integrator rod 120A.

The shape of the light exit surface of the integrator rod 120A is preferably such that the contour shape of the illumination region is similar to the contour shape of the irradiated region. For example, if the contour shape of the irradiated region is a substantially rectangular shape, the contour shape of the light exit surface of the integrator rod 120A is preferably a substantially rectangular shape similar to this. However, since the central axis of the light source device 110A is arranged to be inclined with respect to the central axis of the micromirror type modulation device 200, the actual illumination area that illuminates the irradiated area has a distorted contour according to this inclination. Will have a shape. Therefore, in such a case, the shape of the light exit surface of the integrator rod 120A is more preferably a shape that corrects the distortion of the contour of the illumination area.
The light incident on the integrator rod 120A passes through the integrator rod 120A while being repeatedly reflected on the inner surface of the integrator rod 120A. Thereby, the integrator rod 120A can make the illuminance distribution uniform on the light exit surface of the light having a non-uniform illuminance distribution emitted from the light source device 110A.

  A color wheel 130 is provided on the light exit surface side of the integrator rod 120A. As shown in FIG. 1E, the color wheel 130 has a structure in which red, green and blue color filters are arranged in a spiral shape. Note that the color wheel 130 can be omitted, and the image projected in this case is a monochrome image.

  The relay optical system 140 has a function of forming an image of the light exit surface of the integrator rod 120 </ b> A on the image forming region of the micromirror type modulation device 200. Although the relay lens 142 shown in FIG. 1A is composed of one lens, it may be composed of a compound lens in which a plurality of lenses are combined.

The micromirror-type modulation device 200 emits image light representing an image to the projection optical system 300 by reflecting light from the relay optical system 140 with a micromirror corresponding to each pixel according to an image signal (image information). This is a reflection direction control type light modulation device having the function of: The image light emitted from the micromirror type modulation device 200 is projected on a projection surface such as a screen SCR via the projection optical system 300. Thereby, the image represented by the image light is projected and displayed.
The micromirror type modulation device 200 and the projection optical system 300 are arranged so that their central axes coincide. When the projector 100A according to the first embodiment is a projector having a tilting projection configuration, the projection optical axis 300ax of the projection optical system 300 is shifted in the tilting direction with respect to the central axis of the micromirror type modulation device 200. It is preferable to configure.

  As shown in FIG. 1C, the illumination light beam emitted from the light source device 110A becomes an illumination light beam Bi having a circular cross section on the light incident surface of the integrator rod 120A, and on the light emission surface of the integrator rod 120A, As shown in FIG. 1D, the illumination light beam Bo has a rectangular cross section. The illumination light beam Bo passes through the color wheel 130 as shown in FIG. 1 (e), and as shown in FIG. 1 (f), the illumination light beam Bo includes three color components of red, green, and blue. The luminous flux is Bw. Then, as shown in FIG. 1G, the illumination light beam Bw is enlarged by the relay optical system 140 and irradiated onto the image forming region of the micromirror type modulation device 200.

Next, the light source device 110A will be described.
According to the projector 1000A according to the first embodiment, as described above, since the auxiliary mirror 116A is attached to the arc tube 112, the angle of the focused light emitted from the light source device 110A can be reduced. For this reason, the incident angle of the focused light incident on the integrator rod 120A can be reduced, and the utilization efficiency of the illumination light in the illumination device 100A can be easily improved.

  Further, according to the projector 1000A according to the first embodiment, as described above, since the auxiliary mirror 116A is attached to the arc tube 112, the shape and size of the tube and the arrangement position of the electrode are provided for each arc tube. Even if there is a non-negligible variation in the position of the emission center, etc., the above-described variation can be absorbed by adjusting the mounting position of the auxiliary mirror with respect to the arc tube according to the variation. become. As a result, the projector 1000A according to the first embodiment is a projector provided with the micromirror type modulation device 200, in which the light use efficiency does not decrease and the stray light level does not increase.

  Further, according to the projector 1000A according to the first embodiment, the integrator rod 120A is made of a solid glass rod with total internal reflection, so that the light incident on the integrator rod 120A is reflected while being totally reflected by the inner surface of the integrator rod 120A. Proceed toward the exit surface. For this reason, since the reflection loss in the integrator rod 120A is eliminated, the light utilization efficiency is improved.

  In the projector 1000A according to the first embodiment, the arc tube 112 includes a tube bulb portion that bulges in the center and a seal portion that extends from the tube bulb portion to both sides, and a seal portion on one side of the arc tube 112. Is attached with an ellipsoidal reflector 114A, and an auxiliary mirror 116A is attached to the other sealing portion. The auxiliary mirror 116A is fixed to the arc tube 112 after the position adjustment with respect to the arc tube 112 is made.

  For this reason, the auxiliary mirror 116A is fixed to the arc tube 112 after adjusting the above-described variation by adjusting the attachment position of the auxiliary mirror 116A with respect to the arc tube 112, and thus the fixed auxiliary mirror 116A emits light. The light emitted from the tube 112 toward the illuminated area is always reflected correctly toward the light emitting portion of the light emitting tube 112. Thereafter, the light that has passed through the light emitting portion of the arc tube 112 is reflected by the ellipsoidal reflector 114A and correctly reaches the light incident surface of the integrator rod 120A, so that the light use efficiency is reduced or the stray light level is increased. Disappears.

  In the projector 1000A according to the first embodiment, the auxiliary mirror 116A is fixed to the sealing portion on the opposite side of the ellipsoidal reflector 114A in the arc tube 112.

  For this reason, it is possible to easily adjust the position of the auxiliary mirror 116A with respect to the arc tube 112 and then fix the auxiliary mirror 116A to the arc tube 112.

  In projector 1000A according to Embodiment 1, auxiliary mirror 116A is made of quartz glass. A reflective film made of a dielectric multilayer film is formed on the inner surface of the auxiliary mirror 116A.

  Since the auxiliary mirror 116A is disposed very close to the arc tube 112, the auxiliary mirror 116A is placed in an extremely high temperature environment. However, as in the projector 1000A according to the first embodiment, the auxiliary mirror is made of quartz glass having a low thermal expansion coefficient and excellent heat resistance, so that deterioration of optical characteristics due to heat is suppressed. Further, by forming the reflective film with a dielectric multilayer film having a low thermal expansion coefficient and excellent heat resistance, deterioration of the reflective characteristics due to heat can be suppressed.

In the projector 1000A according to the first embodiment, an infrared transmissive reflective film is used as the reflective film of the auxiliary mirror 116A. For this reason, since the infrared rays radiated from the arc tube 112 and reaching the auxiliary mirror 116A pass through the auxiliary mirror 116A as they are, an increase in temperature of the auxiliary mirror 116A is suppressed.
Therefore, in the projector 1000A according to the first embodiment, as the dielectric multilayer film, a dielectric made of SiO ₂ as a low refractive dielectric and TiO ₂ and / or Ta ₂ O ₅ as a high refractive index dielectric. A multilayer film is used.

FIG. 2 is a view for explaining the light source device 110A in the projector 1000A according to the first embodiment. 2A is a view of the illumination device 100A including the light source device 110A as viewed from above, and FIG. 2B is a diagram in which illumination light emitted from the emission center is added.
FIG. 3 is a diagram for explaining the light source device 110c in the projector according to the comparative example. FIG. 3A is a view of the illumination device 100c including the light source device 110c as viewed from above, and FIG. 3B is a diagram in which illumination light emitted from the emission center is added.

In the projector 1000A according to Embodiment 1, as shown in FIG. 2, the first focal length _{f 1} of the ellipsoidal reflector 114A is 13 mm, the second focal length _{f 2} of the ellipsoidal reflector 114A is 50 mm, oval The diameter D of the effective reflecting surface of the surface reflector 114A is 47 mm.

Therefore, the projector 1000A according to Embodiment 1, since first focal length _{f 1} of the ellipsoidal reflector 114A is 13 mm, in contact bulb portion of the arc tube 112 and the base portion of the ellipsoidal reflector 114A is There is no end. In addition, it is not necessary to use a large ellipsoidal reflector having a large effective reflection surface diameter in order to secure the amount of light trapped from the arc tube.

Further, according to the projector 1000A according to Embodiment 1, since the second focal length _{f 2} of the ellipsoidal reflector 114A is 50 mm, the light incidence of the illuminated region side of the tip and the integrator rod 120A of the lead portion of the arc tube 112 There is no contact with the surface.

In the projector 1000A according to the first embodiment, as described above, the integrator rod 120A is made of a solid glass rod with a total internal reflection type, so that there is no reflection loss inside the integrator rod 120A, and light utilization efficiency is improved. .
By the way, in the projector 1000A according to the first embodiment, the light from the light source device 110A is refracted at the light incident surface of the integrator rod 120A, so that the light incident on the integrator rod 120A travels toward the light exit surface at a shallower angle. Will come to do. For this reason, in order to realize a sufficient light uniforming effect, it is necessary to make the length of the integrator rod longer as shown in FIG.

However, the incident angle at which incident the projector 1000A according to Embodiment 1, by shortening the 50mm the second focal length _{f 2} of the ellipsoidal reflector 114A, the light source device 110A to the light incident surface of the integrator rod 120A Can be deeper. As a result, it is not necessary to lengthen the length of the integrator rod 120A so much in order to realize a sufficient light uniforming effect.
In the projector 1000A according to Embodiment 1, since the light source device 110A has an auxiliary mirror 116A, as possible to shorten the second focal length _{f 2} as described above, the effective reflection of the ellipsoidal reflector 114A There is no need to increase the diameter of the surface.

  Further, according to the projector 1000A according to the first embodiment, since the diameter D of the effective reflection surface of the ellipsoidal reflector 114A is 47 mm, the reflection area of the ellipsoidal reflector 114A that reflects light from the arc tube 112 is sufficiently large, The amount of light guided to the integrator rod 120A can be made a sufficient amount. In addition, since the ellipsoidal reflector itself is smaller than the conventional one, the lighting device 100A can be downsized.

In the projector 1000A according to the first embodiment, the integrator rod 120A is made of a solid glass rod with a total internal reflection type. Therefore, as described above, it is necessary to make the length of the integrator rod longer.
However, according to the projector 1000A according to the first embodiment, since the light source device 110A includes the auxiliary mirror 116A, as described above, the second focal point is not increased without increasing the diameter of the effective reflecting surface of the ellipsoidal reflector 114A. it is possible to reduce the distance f _2. For this reason, if the diameter D of the effective reflecting surface of the ellipsoidal reflector 114A is 47 mm, the incident angle when entering the light incident surface of the integrator rod 120A from the light source device 110A can be made deeper. For this reason, it is not necessary to lengthen the length of the integrator rod 120A so much in order to realize a sufficient light uniforming effect.

  In the projector 1000A according to the first embodiment, the maximum formed by the ellipsoidal reflector 114A proximal end portion of the illumination optical axis 100Aax of the illumination device 100A and the light emitted from the emission center of the arc tube 112 toward the ellipsoidal reflector 114A. The angle θ is 105 °.

For this reason, in the projector 1000A according to the first embodiment, since the ellipsoidal reflector 114A itself can be made smaller than the conventional one, the size of the illumination device 100A can be reduced.
In the projector 1000A according to the first embodiment, the ellipsoidal reflector 114A is configured to be smaller than the conventional one, but light emitted from the arc tube 112 at an angle exceeding 105 ° is reflected by the auxiliary mirror 116A and is elliptical. Since the light is guided to the surface reflector 114A, the light use efficiency does not decrease.

  As described above, the projector 1000A according to the first embodiment is a small projector in which the length of the integrator rod 120A is short although the diameter D of the effective reflecting surface of the ellipsoidal reflector 114A is not so large.

  The projector 1000A according to the first embodiment further includes a color wheel 130 disposed on the light exit surface side of the integrator rod 120A as shown in FIGS. 1 (a) and 1 (b).

  Therefore, according to the projector 1000A according to the first embodiment, since the angle of the focused light emitted from the light source device 110A can be reduced, the incident angle of the focused light incident on the integrator rod 120A can be reduced. . As a result, the emission angle of the light emitted from the integrator rod 120A can be reduced, and the blurring of the image on the image forming area of the micromirror type modulator 200 at the boundary of each color filter in the color wheel 130 is reduced. Color reproducibility is improved.

[Embodiment 2]
The second embodiment is an embodiment for explaining how the auxiliary mirror 116D is attached to the arc tube 112D.
FIG. 4 is a cross-sectional view of the light source device 110D used in the projector according to the second embodiment. FIG. 5 is a view for explaining the arc tube 112D and the auxiliary mirror 116D in the light source device 110D. FIG. 6 is a diagram for explaining the auxiliary mirror 116D. FIG. 6A is a view when the auxiliary mirror 116D is viewed along the light source optical axis 110Dax, and FIG. 6B is a cross-sectional view taken along line AA of FIG.

  FIG. 7 is a diagram showing how the auxiliary mirror 116D is attached to the arc tube 112D. FIG. 7A is a partial cross-sectional view along the light source optical axis 110Dax in FIG. 5, and FIG. 7B is a partial cross-sectional view in the case of a modification. FIG. 8 is a diagram showing how the auxiliary mirror 116D is attached to the arc tube 112D. 8A is a partial cross-sectional view taken along the light source optical axis 110Dax in FIG. 5, and FIG. 8B is a cross-sectional view taken along line BB in FIG. 8A. FIG. 9 is a diagram showing how the auxiliary mirror 116D is attached to the arc tube 112D. FIG. 9A is a partial cross-sectional view of the modification of FIG. 8A, and FIG. 9B is a cross-sectional view taken along the line CC of FIG. 9A.

First, the configuration of the light source device 110D used in the projector 1000D (not shown) according to the second embodiment will be described. The projector 1000D according to the second embodiment basically has the same configuration as the projector 1000A according to the first embodiment.
In the light source device 110D, as shown in FIG. 4, an arc tube 112D is arranged inside an ellipsoidal reflector 114D. In the second embodiment, the light emission direction of the light source device 110D is indicated as the distal end side, and the direction opposite to the light emission direction of the light source device 110D is indicated as the proximal end side.

The arc tube 112D is composed of a quartz glass tube having a central portion bulged in a spherical shape, the central portion is a light emitting portion 112D1, and portions extending to both the front side and the rear side of the light emitting portion 112D1 are sealing portions 112D2 and 112D3. It is said.
Inside the light emitting unit 112D1, a pair of tungsten electrodes 112D4 and 112D4 arranged at a predetermined distance from each other, and mercury, a rare gas, and a small amount of halogen are sealed.

Molybdenum metal foils 112D5 and 112D5 electrically connected to the electrodes 112D4 and 112D4 of the light emitting part 112D1 are respectively provided in the sealing parts 112D2 and 112D3 extending to both the front side and the rear side of the light emitting part 112D1. Inserted and sealed with glass material or the like. Lead wires 112D6 and 112D6 as electrode lead lines are further connected to the metal foils 112D5 and 112D5, and the lead wires 112D6 and 112D6 extend to the outside of the arc tube 112D.
Then, when a voltage is applied to the lead wires 112D6 and 112D6, as shown in FIG. 5, a potential difference is generated between the electrodes 112D4 and 112D4 through the metal foils 112D5 and 112D5 to generate a discharge, and an arc image D is generated and a light emitting unit 112D1 emits light.

As shown in FIG. 4, the ellipsoidal reflector 114D includes a neck portion 114D1 through which the sealing portion 112D2 on the proximal end side of the arc tube 112D is inserted, and an ellipsoidal reflection portion 114D2 extending from the neck portion 114D1. It is an integrally molded product made of glass.
An insertion hole 113 is formed at the center of the neck portion 114D1, and the sealing portion 112D2 is disposed at the center of the insertion hole 113.
The reflecting portion 114D2 is configured by depositing a metal thin film on an elliptical glass surface, and the reflecting surface 114D3 of the reflecting portion 114D2 is a cold mirror that reflects visible light and transmits infrared rays and ultraviolet rays.
Reflective surface 114D3 of the ellipsoidal reflector 114D is elliptical surface having a first focal point _{L 1} and the second focal point _{L 2,} first focus _{L 1} and the second focal point _{L 2} is disposed on the light-source optical axis 110Dax.

Such arc tube 112D that is disposed inside the reflecting portion 114D2 of the ellipsoidal reflector 114D, the emission center between the electrodes 112D4,112D4 in illuminator 112D1 is arranged such that the vicinity of the first focal point _{L 1.}
When lighting the arc tube 112D, the light emitted from the illuminator 112D1 is reflected by the reflecting surface 114D3 of the reflecting portion 114D2, a convergent light converging at a second focal point _{L 2} of the ellipsoidal reflector 114D. The central axis of the light beam emitted from the ellipsoidal reflector 114D substantially coincides with the light source optical axis 110Dax.

At this time, the conical inner portion of which is shown by the boundary line _{L 3} and the boundary line _{L 4} connecting the end portion of the tip in the sealing portion 112D3 of the second focal point _{L 2} and the distal end side of the arc tube 112D of the ellipsoidal reflector 114D is , the light reflected by the ellipsoidal reflector 114D can not deliver the light to the second focal point L ₂ is blocked by the sealing portion 112D3, a light unavailable area. In other words, the boundary line _{L 3} and the boundary line _{L 4} connecting the second focal point _{L 2} of the ellipsoidal reflector 114D and the end portion of the tip in the sealing portion 112D3 of the distal end side of the arc tube 112D, by the ellipsoidal reflector 114D is the boundary of the boundary rays of the light beam is intercepted by the sealing portion 112D3 of the reflected light to reach to the second focal point L _2.

When the arc tube 112D is fixed to the ellipsoidal reflector 114D, the sealing portion 112D2 on the rear side of the arc tube 112D is inserted into the insertion hole 113 of the ellipsoidal reflector 114D, and the electrodes 112D4 in the light emitting portion 112D1 are inserted. emission center between 112D4 are disposed so that the vicinity of the first focal point L ₁ of the ellipsoidal reflector 114D, filling the inorganic adhesive mainly composed of silica / alumina inside the insertion hole 113.
Further, the dimension of the reflecting portion 114D2 in the optical axis direction is shorter than the length of the arc tube 112D. When the arc tube 112D is fixed to the ellipsoidal reflector 114D in this way, the sealing portion on the front side of the arc tube 112D is used. 112D3 protrudes from the opening of the ellipsoidal reflector 114D.

  The auxiliary mirror 116D is a reflecting member that covers substantially the front half of the light emitting portion 112D1 of the arc tube 112D. As shown in FIG. 6, the inner surface is a spherical reflecting surface 116D1, and the outer peripheral surface 116D2 is a curvature of the reflecting surface 116D1. It is comprised in the bowl shape comprised by the curved surface shape which imitates. A reflective film is formed on the reflective surface 116D1 by forming a dielectric multilayer film, and this reflective film is a cold mirror similar to the reflective surface 114D3 of the ellipsoidal reflector 114D.

Further, an opening 116D3 is formed in the bottom surface portion of the bowl shape of the auxiliary mirror 116D, and an inner peripheral surface of the opening 116D3 is an adhesive surface filled with an adhesive for fixing to the sealing portion 112D3, which will be described later. 116D4.
Furthermore, the height of the bowl shape gradually decreases from the edge of the reflecting surface 116D1 toward the edge of the outer peripheral surface 116D2 of the bowl-shaped upper end side end face of the auxiliary mirror 116D (the left end face in FIG. 6B). The inclined surface 116D5 is used.
As shown in FIG. 7A, the inclined surface 116D5 is inclined along the maximum angle θ formed by the base end side of the light source optical axis 110Dax and the light emitted from the light emitting unit 112D1 and directly incident on the elliptical reflector 114D. It has a truncated cone shape. The maximum angle θ is the maximum angle formed by the light emitted from the light emitting unit 112D1 and directly incident on the ellipsoidal reflector 114D. In order to shorten the length of the ellipsoidal reflector 114D in the light source optical axis 110Dax direction. , 105 ° or less is preferable.

Such an auxiliary mirror 116D is made of an inorganic material such as quartz or alumina ceramics, or a crystallized glass such as quartz or neo-serum (registered trademark of Shoto Nippon Co., Ltd.), sapphire, alumina ceramics or the like. Specifically, as shown in FIG. 6B, it can be manufactured by polishing a thick cylindrical member 116D6 having an outer diameter D ₁ and an inner diameter D ₂ .
First, one end surface of the cylindrical member 116D6 is polished into a concave curved surface to form a reflective surface 116D1, and then the convex curved outer peripheral surface 116D2 is polished so as to follow the reflective surface 116D1, thereby polishing the inclined surface 116D5. I do. Finally, a dielectric multilayer film made of, for example, tantalum pentoxide (Ta ₂ O ₅ ) and silicon dioxide (SiO ₂ ) is deposited on the reflective surface 116D1.

As shown in FIG. 7A, the attachment position of the auxiliary mirror 116D with respect to the light emitting portion 112D1 of the arc tube 112D is radiated from the light emitting portion 112D1 and directly enters the ellipsoidal reflector 114D as shown in FIG. in the position as the inclined surface 116D5 along maximum angle θ formed by the light is arranged, and the light-source optical axis 110Dax not protruding outer peripheral surface 116D2 conical represented by the boundary line _{L 3} and the boundary line _{L 4} The position is orthogonal.

  In the second embodiment, the inclined surface 116D5 is an inclined surface along the maximum angle θ. However, as shown in FIG. 7B, the inclined surface 116D5 is not incident on the reflecting surface 116E1 of the auxiliary mirror 116E and is an end surface of the auxiliary mirror 116E. If the amount of light shielded by 116E5 is small, the end surface 116E5 of the auxiliary mirror 116E may be configured as a surface orthogonal to the light source optical axis 110Dax.

As shown in FIG. 7A, the auxiliary mirror 116D is fixed to the arc tube 112D by interposing an adhesive 117 between the adhesive surface 116D4 and the outer peripheral surface of the sealing portion 112D3 on the distal end side of the arc tube 112D. The auxiliary mirror 116D is bonded and fixed. The adhesive 117 is applied so as to be raised on the outer peripheral surface 116D2 of the auxiliary mirror 116D. As the material of the adhesive 117, a silica / alumina-based inorganic adhesive can be employed in the same manner as when the arc tube 112D is bonded and fixed to the ellipsoidal reflector 114D.
As shown in FIGS. 8A and 8B, the adhesive 117 may be intermittently applied around the light source optical axis 110Dax, as shown in FIGS. 9A and 9B. Alternatively, it may be applied all around the light source optical axis 110Dax.

  As described above, in the projector 1000D according to the second embodiment, the auxiliary mirror 116D is fixed to the arc tube 112D after the position is adjusted with respect to the arc tube 112D. For this reason, the auxiliary mirror 116D is fixed to the arc tube 112D after adjusting the attachment position of the auxiliary mirror 116D with respect to the arc tube 112D to adjust the variation of the arc tube 112D. The auxiliary mirror 116D always reflects light radiated from the arc tube 112D toward the illuminated area correctly toward the light emitting portion (light emission center) of the arc tube 112D. After that, the light that has passed through the light emitting portion of the arc tube 112D is reflected by the ellipsoidal reflector 114D and correctly reaches the light incident surface of the integrator rod, so that the light utilization efficiency may decrease or the stray light level may increase. Disappear.

  In the projector 1000D according to the second embodiment, the auxiliary mirror 116D is fixed to the sealing portion 112D3 on the opposite side of the ellipsoidal reflector 114D in the arc tube 112D. For this reason, it is possible to easily adjust the position of the auxiliary mirror 116D with respect to the arc tube 112D and then fix the auxiliary mirror 116D to the arc tube 112D.

  The projector of the present invention has been described based on each of the above embodiments. However, the present invention is not limited to each of the above embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are possible.

  The projectors 1000 and 1000D of each of the above embodiments are colors arranged on the light exit surface side of the integrator rod as a color wheel for making a single-plate projector provided with one micromirror type modulation device into a full-color projector. Although it is a projector using a wheel, the present invention is not limited to this, and may be a projector using a color wheel arranged on the light incident surface side of the integrator rod.

FIG. 3 is a diagram for explaining a projector 1000A according to the first embodiment. FIG. 3 is a diagram for explaining a light source device 110A in a projector 1000A according to the first embodiment. The figure shown in order to demonstrate the light source device 110c in the projector which concerns on a comparative example. Sectional drawing of light source device 110D used for the projector which concerns on Embodiment 2. FIG. The figure shown in order to demonstrate the arc tube 112D and auxiliary | assistant mirror 116D in light source device 110D. The figure shown in order to demonstrate auxiliary | assistant mirror 116D. The figure which shows how auxiliary | assistant mirror 116D is attached with respect to the arc_tube | light_emitting_tube 112D. The figure which shows how auxiliary | assistant mirror 116D is attached with respect to the arc_tube | light_emitting_tube 112D. The figure which shows how auxiliary | assistant mirror 116D is attached with respect to the arc_tube | light_emitting_tube 112D. The figure shown in order to demonstrate the projector 1000a provided with the conventional micromirror type modulation apparatus. It is a figure which shows the other conventional light source device 110b.

Explanation of symbols

100A, 100a, 100c ... Illumination device, 100Aax, 100aax, 100cax ... Illumination optical axis, 110A, 110D, 110a, 110b, 110c ... Light source device, 110Dax ... Light source optical axis, 112, 112D, 112a, 112b ... Arc tube, 112D1 Light emitting part, 112D2, 112D3 ... Sealing part, 112D4 ... Electrode, 112D5 ... Metal foil, 112D6 ... Lead wire, 113 ... Insertion hole, 114A, 114D, 114a, 114b, 114c ... Elliptical reflector, 114D1 ... Neck-shaped part , 114D2 ... reflective portion, 116A, 116D, 116E, 116c ... auxiliary mirror, 116D1,116E1 ... reflective surface, 116D2 ... outer peripheral surface, 116D3 ... opening portion, 116D4, 116E4 ... adhesive surface, 116D5 ... inclined surface, 116E5 ... end surface, 116D6 ... yen 120A, 120a, 120c ... integrator rod, Bi ... illumination light beam on the light incident surface of the integrator rod, Bo ... illumination light beam on the light exit surface of the integrator rod, 130, 130a ... color wheel, 130aax ... rotating shaft, 140, 140a ... relay optical system, 142 ... relay lens, 144 ... reflective mirror, 150 ... field lens, 160, 170 ... reflective optical system, 162 ... collimating lens, 164 ... reflective mirror, 200, 200a ... micro mirror type modulator, 300 and 300a ... projection optical system, 300ax, 300aax ... projection optical axis, 1000A, 1000a ... projector, D 1 _... outer diameter, D 2 _... inner diameter, L 1 _... first focal point, L 2 _... second focal _{point, L} 3, L ₄ ... boundary line, SCR ... screen

Claims (10)

A light source device having an ellipsoidal reflector and an arc tube having a light emission center in the vicinity of the first focal point of the elliptical reflector, and a light incident surface in the vicinity of the second focal point of the elliptical reflector, and making the light from the light source device more uniform A lighting device including an integrator rod that converts light into a light having a uniform intensity distribution;
A relay optical system for guiding light from the illumination device to an illuminated area;
A micro-mirror type modulation device that modulates light from the relay optical system according to image information;
In a projector comprising a projection optical system that projects light modulated by the micromirror type modulation device,
The integrator rod is a solid glass rod with total internal reflection type,
The projector according to claim 1, wherein an auxiliary mirror is attached to the arc tube to reflect light emitted from the arc tube toward the illuminated area toward the ellipsoidal reflector. The projector according to claim 1, wherein
The projector is characterized in that the auxiliary mirror is fixed to the arc tube after its position is adjusted with respect to the arc tube. The projector according to claim 1 or 2,
The projector according to claim 1, wherein the auxiliary mirror is fixed to a sealing portion of the arc tube opposite to the elliptical reflector. The projector according to any one of claims 1 to 3,
The auxiliary mirror is made of quartz glass. The projector according to any one of claims 1 to 4,
A projector characterized in that a reflection film made of a dielectric multilayer film is formed on the inner surface of the auxiliary mirror. In the projector according to any one of claims 1 to 5,
A projector satisfying a relationship of 6 mm ≦ f ₁ ≦ 18 mm, where f ₁ is a first focal length of the ellipsoidal reflector. In the projector according to any one of claims 1 to 6,
A projector satisfying a relationship of 30 mm ≦ f ₂ ≦ 90 mm, where f ₂ is a second focal length of the ellipsoidal reflector. In the projector according to any one of claims 1 to 7,
A projector satisfying a relationship of 30 mm ≦ D ≦ 50 mm, where D is a diameter of an effective reflection surface of the elliptical reflector. The projector according to any one of claims 1 to 8,
When the maximum angle formed by the light emitted from the light emitting center of the arc tube to the ellipsoidal reflector is 90 ° ≦ θ ≦ 90 ° ≦ θ ≦ A projector characterized by satisfying a relationship of 110 °. The projector according to any one of claims 1 to 9,
The projector further comprising a color wheel disposed on the light exit surface side of the integrator rod.