JP2008108701A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of preventing increase in temperature of a tubular bulb part as a whole while improving light using efficiency, of preventing reduction in a life of a light source device, and of preventing complication of film designing/forming work. <P>SOLUTION: The projector is provided with a light source device 110 having an arc tube 20, which has the tubular bulb part 30 and a pair of sealing parts 40 and 50, and an elliptical face reflector 10 reflecting light from the arc tube 20 to a lighted area side, a liquid crystal device modulating lighting light flux from the light source device according to image information, and a projection optical system projecting the light modulated by the liquid crystal device. In a central area A<SB>2</SB>on the outside face of the tubular bulb part 30, an increased transmission film 70 having a property increasing light transmittance of a viewable area in comparison with a part having no increased transmission film 70 is formed, while no increased transmission film 70 is formed in one sealed part side area A<SB>1</SB>and the other sealing part side area A<SB>3</SB>on the outside face of the tubular bulb part 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector.

  2. Description of the Related Art Conventionally, as a light source device used for a projector, a light source device in which an antireflection film is formed on the entire outer surface of a tube portion in an arc tube is known (see, for example, Patent Document 1). The antireflection film has a characteristic that the reflectance of light in the visible region is lower than the reflectance of light in a wavelength region other than the visible region. According to the conventional light source device, since the antireflection film is formed on the entire outer surface of the tube portion, it is possible to suppress the reflection loss of visible light when passing through the outer surface (surface) of the tube portion, Light utilization efficiency can be improved. As a result, a projector using a conventional light source device is a high-brightness projector.

JP-A-4-368768

  By the way, in the conventional light source device, the antireflection film is designed so that the reflectance of light in the visible region can be kept low, but in other wavelength regions (such as the ultraviolet region and the infrared region) other than the visible region. Since the reflectance of light is relatively high, part of the light in the other wavelength region reflected by the antireflection film is converted into heat, resulting in an overall increase in the temperature of the tube portion. In addition, when light passes through the antireflection film, a part of the light is absorbed by the antireflection film, and the light absorbed by the antireflection film is converted into heat. It will be very high.

  That is, in the conventional light source device, there is a problem that the temperature of the tube part becomes high as a whole due to the formation of the antireflection film on the entire outer surface of the tube part (first problem). )

  Moreover, in the conventional light source device, the temperature of the upper apex portion with respect to the gravity in the bulb portion tends to be particularly high due to heat convection, and the allowable temperature of the base material constituting the bulb portion has been exceeded. In some cases, local swelling or whitening may occur in the upper apex portion of the tube portion. Whitening is a phenomenon in which the base material constituting the tube portion becomes clouded and devitrified. When local swelling occurs in the bulb portion, the arc tube may rupture due to a decrease in strength. Further, when the tube bulb portion is whitened, light transmission is hindered at the whitened portion, and as a result, heat is generated and the temperature of the arc tube further rises. As a result, the arc tube may burst. .

  That is, in the conventional light source device, the temperature at the upper apex portion with respect to the gravity at the bulb portion tends to be particularly high due to thermal convection and the like. There is a problem (second problem) that a blister may occur or whitening may occur. If local swelling occurs or whitens at the upper apex portion of the bulb portion, the lifetime of the light source device is reduced.

  Further, in the conventional light source device, the outer surface of the bulb portion is formed by one sealing portion side region, the other sealing portion side region, one sealing portion side region, and the other sealing portion side region. When the outer surface of the tube is coated with an anti-reflection film when divided into three regions, the central region located between them, the coating material adhesion angle (axis and tube parallel to the scattering direction of the coating material) Since the angle formed with the normal to the outer surface of the part is different between the sealing part side region (one sealing part side region or the other sealing part side region) and the central region, the sealing part side region and the center There is a problem (third problem) that the film characteristics may differ between regions. If the film characteristics are different between the sealing portion side region and the central region, it becomes difficult to improve the light utilization efficiency as desired. Therefore, when forming an antireflection film on the outer surface of the tube part, it is preferable to design the film so that the film characteristic of the sealing part side region and the film characteristic of the central region are as much as possible. Thus, when the problem of film characteristics is taken into consideration, the film design and film formation work becomes complicated.

  As a means for solving the first problem among the above three problems, the air flow rate is increased by increasing the rotation speed of the cooling fan for cooling the arc tube, or a larger cooling fan is used. It is conceivable to strengthen the cooling of the arc tube, for example, but noise increases when the rotation speed of the cooling fan is increased to increase the air volume, and a larger cooling fan is used. In some cases, the apparatus becomes large and the manufacturing cost becomes high, so that it is not preferable to enhance the cooling of the arc tube.

  Further, as a means for solving the first problem among the above three problems, it is conceivable to remove all of the antireflection film formed on the entire outer surface of the tube portion. In this case, it is possible to suppress the overall temperature of the tube portion from being increased, but it is possible to increase the transmittance of visible light when passing through the outer surface of the tube portion. Therefore, the light use efficiency cannot be improved.

  It should be noted that the second problem cannot be solved by “strengthening the cooling of the arc tube” and “removing all of the antireflection film formed on the entire outer surface of the bulb”. Further, the third problem cannot be solved by “enhance arc tube cooling”.

  Therefore, the present invention is for solving the above-described problems, and it is possible to suppress the overall temperature of the tube portion from increasing while improving the light utilization efficiency. It is another object of the present invention to provide a projector that can suppress a reduction in the lifetime of the light source device and that does not complicate film design and film formation operations.

  The projector of the present invention includes a tube bulb portion including a pair of electrodes arranged along the illumination optical axis, a light emitting tube having one sealing portion and the other sealing portion extending on both sides of the tube bulb portion, A light source device that is disposed on the one sealing portion side and has a reflector that reflects light from the arc tube toward the illuminated region side, and modulates illumination light flux from the light source device according to image information And a projection optical system that projects the light modulated by the electro-optic modulation device, the outer surface of the tube portion is positioned on the one sealing portion side. A stop portion side region, the other sealing portion side region located on the other sealing portion side, a central region located between the one sealing portion side region and the other sealing portion side region; When divided into three areas, the outer surface of the tube section In the central region, a permeable membrane is formed, and in the outer surface of the tube portion, the permeable membrane is formed in the one sealing portion side region and the other sealing portion side region. In addition, the increased transmission film has a characteristic of increasing the light transmittance at least in the visible region as compared with a portion where the increased transmission film is not formed.

  For this reason, according to the projector of the present invention, the one of the sealing portion side region and the other sealing portion side region on the outer surface of the tube portion is not formed with a reflection increasing film. Therefore, compared with the case where an antireflection film is formed on the entire outer surface of the tube portion as in the conventional light source device, the temperature of the tube portion is prevented from becoming higher overall. Is possible.

  Further, according to the projector of the present invention, the temperature of the tube part is entirely reduced by not forming the permeable film in the one sealing part side region and the other sealing part side region on the outer surface of the tube part. Therefore, it is possible to suppress the temperature of the upper apex portion of the tube portion from being increased, and the local apex portion of the upper portion of the tube portion is locally increased. It is possible to suppress the occurrence of blistering or whitening. As a result, it is possible to suppress a decrease in the lifetime of the light source device.

  Further, according to the projector of the present invention, the permeable membrane is formed in the central region on the outer surface of the tube portion, but one sealing portion side region and the other sealing portion side on the outer surface of the tube portion. Since no permeable membrane is formed in the region, there is no problem that the film characteristics are different between the sealing portion side region and the central region, resulting in complicated film design and film formation work. Nothing will happen.

  Further, according to the projector of the present invention, the central transmission region on the outer surface of the tube portion has a transmission film having a property of increasing the light transmittance at least in the visible region as compared with a portion where the transmission film is not formed. Since it is formed, it becomes possible to improve the light utilization efficiency as a whole.

  Therefore, the projector of the present invention can suppress the overall temperature of the tube portion from increasing while improving the light utilization efficiency, and suppress the decrease in the lifetime of the light source device. In addition, the projector is designed such that the film design and film formation work are not complicated.

  In the projector according to the aspect of the invention, it is preferable that the increasing transmission film has a characteristic of increasing a light transmittance of 400 nm to 700 nm as compared with a portion where the increasing transmission film is not formed.

  With this configuration, it is possible to improve the light use efficiency of visible light emitted from the central region on the outer surface of the tube portion.

  In the projector according to the aspect of the invention, it is preferable that the increasing transmission film has a characteristic of increasing a light transmittance of 400 nm to 1500 nm as compared with a portion where the increasing transmission film is not formed.

  By configuring in this way, it becomes possible to improve the light use efficiency of visible light emitted from the central region on the outer surface of the bulb portion, and in the wavelength region of a part of the infrared region continuous to the visible region. It is possible to suppress light from being reflected and converted into heat by the outer surface of the tube portion (a central region in the tube portion). As a result, it is possible to suppress the overall temperature rise of the tube portion while improving the light utilization efficiency.

In the projector according to the aspect of the invention, it is preferable that the increasing transmission film is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ .

  By configuring in this way, it becomes possible to increase the heat resistance of the permeable membrane, and even on the surface of the bulb portion of the arc tube exposed to an extremely high temperature, good permeable properties can be maintained over a long period of time. Is possible.

  In the projector according to the aspect of the invention, the arc tube is an arc tube that produces a lens effect by the inner surface and the outer surface of the bulb portion, and the one sealing portion of the light emitted from the outer surface of the bulb portion It is preferable that an apparent light emission point when a light beam passing through the side region is extended toward the illumination optical axis does not exist in a cylindrical virtual region including the pair of electrodes therein.

By the way, not all of the light emitted from the outer surface of the tube part can be used, and some of the light is difficult to use. For example, as shown in FIG. 5 to be described later, among the light emitted from the outer surface of the tube portion, the light H ₁ passing through the position from the top of the tube portion can be used by being reflected by the ellipsoidal reflector 10. However, the light H ₂ passing through the vicinity of the sealing portion 40 on the ellipsoidal reflector 10 side is blocked by the tube portion 30 after being reflected by the ellipsoidal reflector 10, so that it is difficult to use.

  As described above, the light emitted from the bulb part includes both usable light and light that is difficult to use, but as a result of extensive research conducted by the present inventors, such light that is difficult to use is The apparent light emission point of the light emitted from the outer surface of the tube portion is light that does not exist in the cylindrical virtual region including a pair of electrodes inside, and the available light is from the outer surface of the tube portion. It was found that the apparent light emission point of the emitted light is light existing in a cylindrical virtual region including a pair of electrodes inside.

  Note that the apparent light emission point is an intersection of an extension line obtained by extending a light beam emitted from the outer surface of the bulb portion toward the reflector toward the illumination optical axis and the illumination optical axis. The apparent light emission point is caused by the lens effect of the inner surface and the outer surface of the tube portion, so that the light emitted from the original light emission point existing between the pair of electrodes is reflected on the inner surface and the outer surface of the tube portion. This is because the angle deviates little by little every time it passes.

  According to the projector of the present invention, since the apparent light emission point of the light beam passing through one sealing portion side region (the sealing portion side region on the reflector side) does not exist in the virtual region, light that is difficult to use passes through. In this position, the permeable membrane is not formed. This eliminates the need to form a permeable film at the position where light that is difficult to use passes through during film formation, facilitating film design and film formation work, and at one sealing part side region. It is possible to suppress as much as possible the decrease in light utilization efficiency due to the absence of the permeable increasing film.

  In the projector according to the aspect of the invention, the apparent light emission point when the light beam passing through the central region of the light emitted from the outer surface of the tube portion is extended toward the illumination optical axis is the pair of light beams. It is preferable that it exists in the cylindrical virtual area | region which contains an electrode inside.

  With this configuration, a permeable film is formed at a position where available light passes. As a result, the projector is excellent in terms of improving the light utilization efficiency.

  In the projector according to the aspect of the invention, it is preferable that ω ≦ 45 degrees, where ω is an angle formed between a normal line to the outer surface of the tube portion in the central region and a surface orthogonal to the illumination optical axis.

  When coating the outer surface of the tube portion with a permeable membrane or the like, the coating substance is scattered toward the tube portion from a direction substantially perpendicular to a straight line connecting one sealing portion and the other sealing portion. However, according to the experiment of the present inventor, in such a case, the adhesion angle of the coating material (the angle formed between the axis parallel to the scattering direction of the coating material and the normal to the outer surface of the tube portion) When the angle exceeds 45 degrees, there is a problem that film characteristics are difficult to be obtained. In order to solve such a problem, a means of using a coating material with little angle dependency or increasing the number of films can be considered, but the manufacturing cost becomes high and the film forming operation becomes complicated. Therefore, it is not preferable.

  On the other hand, according to the projector of the present invention, the angle ω formed by the normal to the outer surface of the tube portion in the central region and the surface orthogonal to the illumination optical axis is 45 degrees or less, so the coating material adhesion angle is If replaced, the permeable membrane is formed only in the central region of the tube portion where the adhesion angle is 45 degrees or less, and the above-described problem that the membrane characteristics are difficult to occur does not occur. In addition, since a coating substance with little angle dependency is not used and the number of films is not increased, the manufacturing cost is not increased and the film forming operation is not complicated. As a result, the projector according to the present invention includes a light-emitting tube having excellent film characteristics, and does not increase manufacturing costs or complicate film forming operations.

  In the projector according to the aspect of the invention, it is preferable that the intensity of the light emitted from the central region is 20% or more with respect to the intensity of the light having the highest intensity among the lights emitted from the tube portion.

  With such a configuration, a light-transmitting film is formed in a portion where the light intensity is relatively high, so that the projector is excellent in terms of improving the light utilization efficiency.

  In the projector according to the aspect of the invention, the intensity of the light emitted from the one sealing portion side region and the other sealing portion side region is the highest of the light emitted from the tube portion. It is preferably less than 20% for large light intensity.

  By comprising in this way, the permeation | transmission film | membrane is not formed in the part with comparatively small intensity | strength of light. As a result, it is not necessary to form a permeable film on the part where the light intensity is relatively small at the time of film formation, so that the film design and film formation work becomes easy, and one sealing part side region and It is possible to suppress as much as possible the decrease in light utilization efficiency resulting from the fact that the permeable increasing film is not formed in the other sealing portion side region.

In the projector according to the aspect of the invention, an angle formed by a straight line passing through the boundary between the other sealing portion side region and the central region and a substantially intermediate position between the pair of electrodes and the illumination optical axis of the light source device. When θ ₁ is set, it is preferable that 40 ° <θ ₁ ≦ 55 °.

When the value of θ ₁ is 40 degrees or less, the surface area of the outer surface of the tube part where the permeable membrane is not formed becomes relatively small, and the overall temperature rise of the tube part is suppressed. Is not easy to do. On the other hand, when the value of θ ₁ exceeds 55 degrees, the surface area of the outer surface of the tube portion where the permeable increasing film is not formed becomes relatively large, and the light utilization efficiency is improved. Is no longer easy.
From the above viewpoint, theta ₁ value is preferably 40 ° <θ ₁ ≦ 55 °.

In the projector according to the aspect of the invention, an angle formed by a straight line passing through the boundary between the one sealing portion side region and the central region and a substantially intermediate position between the pair of electrodes and the illumination optical axis of the light source device. When θ ₂ , it is preferable that 40 degrees <θ ₂ ≦ 55 degrees.

When the value of θ ₂ is 40 degrees or less, the surface area of the outer surface of the tube portion where the permeable membrane is not formed becomes relatively small, and the overall temperature rise of the tube portion is suppressed. Is not easy to do. On the other hand, when the value of θ ₂ exceeds 55 degrees, the surface area of the outer surface of the tube portion where the permeable increasing film is not formed becomes relatively large, and the light use efficiency is improved. Is no longer easy.
In view of the above, theta ₂ value is preferably 40 ° <θ ₂ ≦ 55 °.

  In the projector according to the aspect of the invention, the light source device is disposed on the other sealing portion side of the arc tube so as to cover an outer surface of the bulb portion on the illuminated area side, and transmits light from the arc tube. It is preferable to further include a secondary mirror that reflects toward the arc tube.

By the way, it is possible to improve the light utilization efficiency and to reduce the size of the reflector by disposing a secondary mirror at the sealing portion of the arc tube, thereby realizing a high-intensity and compact projector. However, since about half of the bulb part is covered by the secondary mirror, a projector in which the secondary mirror is arranged at the sealing part of the arc tube is provided with such a secondary mirror. There is a tendency that the temperature of the tube part tends to be higher than that of a projector without a projector.
In the present invention, as described above, it is possible to suppress the overall temperature of the bulb portion from being increased, and thus the secondary mirror is disposed in the sealing portion of the arc tube as described above. This is particularly effective for projectors.

Also, in a projector in which a secondary mirror is disposed at the sealing portion of the arc tube, light reflected by the secondary mirror among the light emitted from the arc tube is emitted from the arc tube and then reflected by the secondary mirror. Thus, the light passes through the outer surface of the tube portion a plurality of times before passing through the arc tube again and entering the reflector.
Since the present invention makes it possible to increase the transmittance of visible light when passing through the outer surface of the bulb portion as described above, the secondary mirror is disposed in the sealing portion of the arc tube as described above. This is especially effective for projectors.

  Further, in a projector in which a secondary mirror is disposed at the sealing portion of the arc tube, a space is formed between the bulb portion and the secondary mirror, so that the bulb portion can be effectively cooled. It is possible to extend the life of the arc tube.

  In the projector according to the aspect of the invention, a straight line passing through the boundary portion between the one sealing portion side region and the central region and a substantially intermediate position between the pair of electrodes is covered with the secondary mirror on the outer surface of the tube portion. It is preferable to pass through a boundary portion between the portion that is not covered with the secondary mirror on the outer surface of the tube portion.

  With this configuration, although the light use efficiency is slightly reduced, it is possible to further suppress the overall temperature rise of the tube portion.

  In the projector according to the aspect of the invention, in the region including the apex portion on the lower side with respect to the gravity on the outer surface of the tube portion, the permeable film is formed, and the gravity on the outer surface of the tube portion is against In the region including the upper apex portion, it is preferable that the permeation enhancement film is not formed.

  According to the projector of the present invention, the temperature of the tube portion is increased as a result of the absence of the permeable membrane formed in the region including the upper apex portion with respect to gravity on the outer surface of the tube portion. Therefore, it is possible to suppress the temperature of the upper apex portion in the tube portion from becoming high, and local bulging occurs in the upper apex portion of the tube portion or white Can be suppressed. As a result, it is possible to suppress a decrease in the lifetime of the light source device.

  Further, according to the projector of the present invention, the light transmission efficiency is improved as a whole because the thick transmission film is formed in the region including the apex portion below the gravity on the outer surface of the tube portion. Is possible.

  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 illustrating an optical system of a projector 1000 according to the first embodiment. FIG. 2 is a diagram for explaining the light source device 110. 2A is a diagram schematically illustrating the light source device 110, FIG. 2B is a side view of the tube portion 30, and FIG. 2C is a perspective view of the tube portion 30. FIG. 3 to 6 are conceptual diagrams shown for explaining the regions on the outer surface of the tube portion 30 and the positions where the permeable membrane 70 is formed. FIG. 7 is a diagram showing the light distribution characteristics of the light emitted from the tube portion 30. FIG. 8 is a diagram showing the spectral characteristics of the permeable increasing film 70. FIG. 8 shows the spectral characteristics of the increased transmission film 70 and also shows the spectral characteristics when the increased transmission film 70 is not formed.

In the following description, three directions orthogonal to each other are defined as a z-axis direction (illumination optical axis 100ax direction in FIG. 1), an x-axis direction (a direction parallel to the paper surface in FIG. 1 and perpendicular to the z-axis), and y. Let it be an axial direction (a direction perpendicular to the paper surface in FIG. 1 and perpendicular to the z-axis).
Further, in the following description, the case where projector 1000 is arranged in a so-called stationary state is exemplarily shown, and therefore the direction of gravity is the lower direction (for example, the y (−) direction in FIG. 2A). It becomes.

  As shown in FIG. 1, the projector 1000 according to the first embodiment separates the illumination device 100 and the illumination light flux from the illumination device 100 into three color lights of red light, green light, and blue light and guides them to the illumination area. The three color liquid crystal devices 400R, 400G, and 400B as electro-optic modulation devices that modulate the light-separated color separation light guide optical system 200 and the three color lights separated by the color separation light guide optical system 200 according to image information. And a cross dichroic prism 500 that combines the color lights modulated by the three liquid crystal devices 400R, 400G, and 400B, and a projection optical system 600 that projects the light combined by the cross dichroic prism 500 onto a projection surface such as a screen SCR. It is a projector provided.

  The illumination device 100 includes a light source device 110 that emits an illumination light beam toward the illuminated region, a concave lens 90 that emits the focused light from the light source device 110 as substantially parallel light, and a plurality of portions of the illumination light beam emitted from the concave lens 90. A first lens array 120 having a plurality of first small lenses 122 for dividing the light beam, and a second lens having a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The array 130, the polarization conversion element 140 that converts each partial light flux from the second lens array 130 into substantially one type of linearly polarized light having the same polarization direction and emits the light, and each partial light flux emitted from the polarization conversion element 140 And a superimposing lens 150 for superimposing the image on the illuminated area.

  As shown in FIGS. 1 and 2A, the light source device 110 includes an ellipsoidal reflector 10 as a reflector, and an arc tube 20 having a light emission center near the first focal point of the ellipsoidal reflector 10. The light source device 110 emits a light beam having the illumination optical axis 100ax as a central axis.

  As shown in FIG. 2, the arc tube 20 includes a tube bulb 30 containing a pair of electrodes 42 and 52 arranged along the illumination optical axis 100ax, and a pair of sealing portions extending on both sides of the tube bulb 30. 40, 50, a pair of metal foils 44, 54 sealed in the pair of sealing portions 40, 50, respectively, and a pair of lead wires 46, electrically connected to the pair of metal foils 44, 54, respectively. 56.

If the conditions of the constituent elements of the arc tube 20 are exemplarily shown, the tube portion 30 and the sealing portions 40 and 50 are made of, for example, quartz glass, and mercury or a rare gas is contained in the tube portion 30. And a small amount of halogen is enclosed. The electrodes 42 and 52 are, for example, tungsten electrodes, and the metal foils 44, 54 are, for example, molybdenum foils. The lead wires 46 and 56 are made of, for example, molybdenum or tungsten.
Further, as the arc tube 20, various arc tubes that emit light with high luminance can be employed, for example, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, or the like.

As shown in FIG. 3, the outer surface of the tube portion 30 has one sealing portion side region (predetermined region on the sealing portion 40 side) A ₁ and the other sealing portion side region (on the sealing portion 50 side). When divided into three regions of a predetermined region) A ₃ and a central region A ₂ located between _one sealing portion side region A ₁ and the other sealing portion side region A ₃ , In the central region A ₂ on the outer surface, a permeable increasing film 70 is formed. In one sealing portion side region A ₁ and the other sealing portion side region A ₃ on the outer surface of the tube portion 30, a permeable increase is made. The film 70 is not formed (see FIGS. 2 and 4).

In the projector 1000 according to the first embodiment, as shown in FIG. 4, the outer surface of the tube portion 30 is placed on one sealing portion side area A ₁ and the other so that the values of θ ₁ and θ ₂ are 45 degrees. It is divided into three regions of the sealing portion side region a ₃ of the central region a _2. The permeable membrane 70 is formed only in the central region A ₂ on the outer surface of the tube portion 30, and one sealing portion side region A ₁ and the other sealing portion side region A on the outer surface of the tube portion 30. ₃ does not have a permeable membrane 70 formed thereon.
Note that θ ₁ is “a straight line passing through the other sealing portion side region A ₃ and the boundary portion b ₃ of the central region A ₂ on the upper side of the tube portion 30 and the substantially intermediate position P between the pair of electrodes 42 and 52. L ₃ "and" angle of the illumination optical axis 100ax "of the light source device 110 (" boundary b ₄ of the tube spherical portion other sealing portion side area a ₃ of the lower 30 and the central region a ₂ and a pair of This is the angle formed by the straight line L ₄ ”passing through the substantially intermediate position P of the electrodes 42 and 52 and the“ illumination optical axis 100ax of the light source device 110 ”.
Further, θ ₂ is “a straight line passing through the boundary portion b ₁ between the _one sealing portion side region A ₁ and the central region A ₂ on the upper side of the tube portion 30 and the substantially intermediate position P between the pair of electrodes 42 and 52. L ₁ "and the angle formed by" illumination optical axis 100ax of the light source device 110 "(" the boundary portion b ₂ of one sealing portion side region A ₁ and the central region A ₂ below the tube portion 30 and a pair of This is the angle formed by “a straight line L ₂ ” passing through a substantially intermediate position P between the electrodes 42 and 52 and “the illumination optical axis 100ax of the light source device 110”.

Here is omitted due illustrated around a substantially intermediate position P of the pair of electrodes 42 and 52, the solid angle corresponding to the one sealing portion side region A ₁ and Omega _1, other sealing portion when the solid angle corresponding to the area _{a 3} and Omega _2, in the projector 1000 of embodiment _{1, Ω 1 = Ω 2 =} π [sr (steradian: steradian)] to become.

By the way, not all of the light emitted from the outer surface of the tube portion 30 is available, and there is light that is difficult to use in some cases. For example, as shown in FIG. 5, among the light emitted from the outer surface of the tube portion 30, the light H ₁ passing through the position from the top of the tube portion 30 can be used by being reflected by the ellipsoidal reflector 10. However, the light H ₂ that passes through the vicinity of the sealing portion 40 on the ellipsoidal reflector 10 side is blocked by the tube portion 30 after being reflected by the ellipsoidal reflector 10, making it difficult to use (FIG. 5). (See (a).)

In the projector 1000 according to the first embodiment, as shown in FIG. 5B, the light beam H ₂ apparently passing through _one sealing portion side region A ₁ (sealing portion side region on the ellipsoidal reflector 10 side). emission point c ₂ is absent in a cylindrical shape in the virtual area R including a pair of electrodes 42 and 52 therein, when the extended light H ₁ passing through the center region a ₂ toward the illumination optical axis 100ax emission point c ₁ of the apparent, to be present in the virtual area R, the sealing portion side region a ₃ outer surface one sealing portion side region a ₁ and the other of the tube spherical portion 30 and the central region a ₂ It is divided into three areas.

  The apparent light emission point is an intersection of an extension line obtained by extending a light beam emitted from the outer surface of the bulb portion 30 toward the ellipsoidal reflector 10 toward the illumination optical axis 100ax and the illumination optical axis 100ax. It is. The apparent light emission point is generated as described above due to the lens effect of the inner surface and the outer surface of the tube portion 30, and the original light emission point existing between the pair of electrodes 42 and 52 (the abbreviation of the pair of electrodes 42 and 52). This is because each time a light beam emitted from the intermediate position P) passes through the inner surface and the outer surface of the tube portion 30, the angle is gradually shifted (see FIG. 5B).

  By the way, when coating the outer surface of the tube portion 30 with a permeable membrane or the like, as shown in FIG. 6, a direction substantially orthogonal to a straight line connecting one sealing portion 40 and the other sealing portion 50. Normally, the coating material is scattered from the (alpha direction in FIG. 6) toward the tube portion 30, but according to the experiments of the present inventors, in such a case, the adhesion angle of the coating material (of the coating material) If the angle ω between the axis parallel to the scattering direction (α direction) and the normal line N with respect to the outer surface of the tube portion 30 exceeds 45 degrees, there is a problem that film characteristics are difficult to be obtained. In order to solve such a problem, a means of using a coating material with little angle dependency or increasing the number of films can be considered, but the manufacturing cost becomes high and the film forming operation becomes complicated. Therefore, it is not preferable.

Therefore, in the projector 1000 of embodiment 1, when the angle between a plane perpendicular to the normal line N to the illumination optical axis 100ax for the outer surface of tube portion 30 in the central region A ₂ was set to omega, omega ≦ 45 as the degree, and divides the outer surface of the tube spherical portion 30 into three regions of the one sealing portion side region a ₁ and the other sealing portion side region a ₃ and the central region a _2.

In the projector 1000 according to the first embodiment, the intensity of light emitted from the central area A ₂ (intensity of light emitted from a range of 45 degrees to 135 degrees in FIG. is 20% or more of the intensity of the high light of the most intensity of the emitted light, intensity of light emitted respectively from the one sealing portion side region a ₁ and the other sealing portion side region a _3, such that less than 20% with respect to high light intensity of the strongest of the light emitted from the tube spherical portion 30, one sealing portion side region a ₁ and the other sealing an outer surface of the tube spherical portion 30 The area is divided into three areas, a partial area A ₃ and a central area A ₂ .

The increased transmission film 70 is composed of a multilayer film of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), and has a light reflectance of 400 nm to 700 nm at other wavelengths as shown in FIG. It has a low characteristic compared with the reflectance of light in the region. That is, the permeable increasing film 70 has a characteristic of increasing the light transmittance of 400 nm to 700 nm as compared with the case where the permeable increasing film 70 is not formed.

Various methods such as a vapor deposition method, a dipping method, an ion plating method, and a sputtering method can be used as a method for forming the permeable film 70 on the outer surface of the tube portion 30. For example, a portion (one sealing portion side region A ₁ and the other sealing portion side region A ₃ ) where the permeable membrane 70 is not formed is covered with a masking tape or the like, and tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ) are alternately deposited, whereby the permeable film 70 can be formed only in the central region A ₂ on the outer surface of the tube portion 30.

  As shown in FIG. 2A, the ellipsoidal reflector 10 is radiated from the arc tube 20 and the opening 12 for inserting and fixing the seal portion (one seal portion) 40 of the arc tube 20. And a reflective concave surface that reflects light toward the second focal position. The ellipsoidal reflector 10 is fixed to the sealing portion 40 of the arc tube 20 with an inorganic adhesive such as cement filled in the opening 12 of the ellipsoidal reflector 10.

For example, crystallized glass, alumina (Al ₂ O ₃ ), or the like can be suitably used as the material for the base material constituting the reflective concave surface 14. On the inner surface of the reflective concave surface 14, for example, a visible light reflecting layer made of a dielectric multilayer film of titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ) is formed.

  As shown in FIG. 1, the concave lens 90 is disposed on the illuminated area side of the ellipsoidal reflector 10. The light from the ellipsoidal reflector 10 is emitted toward the first lens array 120.

  The first lens array 120 has a function as a light beam splitting optical element that splits light from the concave lens 90 into a plurality of partial light beams, and a plurality of first small lenses 122 are provided in a plane orthogonal to the illumination optical axis 100ax. It has a configuration arranged in a matrix of rows and columns. Although not illustrated, the outer shape of the first small lens 122 is similar to the outer shape of the image forming area of the liquid crystal devices 400R, 400G, and 400B.

  The second lens array 130 has a function of forming an image of each first small lens 122 of the first lens array 120 in the vicinity of the image forming area of the liquid crystal devices 400R, 400G, and 400B together with the superimposing lens 150. The second lens array 130 has substantially the same configuration as the first lens array 120, and a plurality of second small lenses 132 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 100ax. Have a configuration.

The polarization conversion element 140 is a polarization conversion element that emits the polarization direction of each partial light beam divided by the first lens array 120 as approximately one type of linearly polarized light having a uniform polarization direction.
The polarization conversion element 140 transmits one linearly polarized light component among the polarized light components included in the illumination light beam from the light source device 110 and reflects the other linearly polarized light component in a direction perpendicular to the illumination optical axis 100ax, and A reflection layer that reflects the other linearly polarized light component reflected by the polarization separating layer in a direction parallel to the illumination optical axis 100ax, and a phase difference that converts one linearly polarized light component transmitted through the polarized light separating layer into the other linearly polarized light component And a board.

  The superimposing lens 150 condenses a plurality of partial light beams that have passed through the first lens array 120, the second lens array 130, and the polarization conversion element 140, and superimposes them on the vicinity of the image forming regions of the liquid crystal devices 400R, 400G, and 400B. It is an element. The superimposing lens 150 is arranged so that the optical axis of the superimposing lens 150 and the illumination optical axis 100ax of the illumination device 100 substantially coincide. The superimposing lens 150 may be composed of a compound lens in which a plurality of lenses are combined.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, an incident side lens 260, and a relay lens 270. The color separation light guide optical system 200 separates the illumination light beam emitted from the superimposing lens 150 into three color lights of red light, green light, and blue light, and each of the three color liquid crystal devices 400R to be illuminated. , 400G, 400B.

  Condensing lenses 300R, 300G, and 300B are disposed in the front stage of the optical path of the liquid crystal devices 400R, 400G, and 400B.

The liquid crystal devices 400 </ b> R, 400 </ b> G, and 400 </ b> B modulate the illumination light beam according to the image information and are the illumination target of the illumination device 100.
The liquid crystal devices 400R, 400G, and 400B are a pair of transparent glass substrates in which a liquid crystal that is an electro-optical material is hermetically sealed. For example, incident side polarization is performed according to given image information using a polysilicon TFT as a switching element. The polarization direction of one type of linearly polarized light emitted from the plate is modulated.

  Although not shown here, incident-side polarizing plates are interposed between the condenser lenses 300R, 300G, and 300B and the liquid crystal devices 400R, 400G, and 400B, and the liquid crystal devices 400R, 400G, and 400B are disposed. Between the 400B and the cross dichroic prism 500, an exit side polarizing plate is interposed. The incident-side polarizing plate, the liquid crystal devices 400R, 400G, and 400B and the exit-side polarizing plate modulate light of each color light incident thereon.

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the exit side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on the substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form a large screen image on the screen SCR.

According to the projector 1000 according to the first embodiment configured as described above, the one of the sealing portion side region A ₁ and the other sealing portion side region A ₃ on the outer surface of the tube portion 30 has a permeable increasing film 70. Is not formed, and no antireflection film is formed. Therefore, compared with the case where the antireflection film is formed on the entire outer surface of the tube portion as in the conventional light source device, the tube portion 30 has It becomes possible to suppress that temperature becomes high as a whole.

Further, according to the projector 1000 of embodiment 1, the transmission increasing film 70 is not formed on one of the sealing portion side region A ₁ and the other sealing portion side area A ₃ on the outer surface of the tube spherical portion 30 Therefore, since it becomes possible to suppress that the temperature of the tube part 30 becomes high as a whole, it is possible to suppress the temperature of the upper apex part 32 of the tube part 30 from being increased, It is possible to suppress the occurrence of local swelling or whitening at the apex portion 32 on the upper side of the tube portion 30. As a result, it is possible to suppress a decrease in the lifetime of the light source device 110.

Further, according to the projector 1000 according to the first embodiment, the permeable film 70 is formed in the central region A ₂ on the outer surface of the tube portion 30, but one sealing portion side on the outer surface of the tube portion 30. since the region a ₁ and the other sealing portion side region a ₃ is not formed transmission increasing film 70, also a problem that the film properties becomes different between the sealing portion side region and the central region is generated As a result, the film design / film formation work is not complicated.

Further, according to the projector 1000 of embodiment 1, the central region A ₂ on the outer surface of the tube spherical portion 30, to increase the light transmission of at least the visible region as compared to the portion where transmission increasing film 70 is not formed Since the permeable increasing film 70 having the characteristics is formed, it is possible to improve the light utilization efficiency as a whole.

  Therefore, the projector 1000 according to the first embodiment can suppress the overall temperature of the tube portion 30 from being increased while improving the light use efficiency, and the life of the light source device 110 can be reduced. In addition, the projector can be prevented from being complicated in film design and film formation.

In the projector 1000 according to the first embodiment, the transmissive film 70 has a characteristic of increasing the light transmittance of 400 nm to 700 nm as compared with the portion where the transmissive film 70 is not formed. it is possible to improve the light use efficiency of visible light emitted from the central region a ₂ in.

In the projector 1000 according to the first embodiment, since the permeable film 70 is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ , the heat resistance of the permeable film 70 can be increased, and the temperature is extremely high. Also on the surface of the bulb portion 30 of the arc tube 20 exposed to the above, it is possible to maintain good increased transmission characteristics over a long period of time.

When the values of θ ₁ and θ ₂ are 40 degrees or less, the surface area of the outer surface of the tube portion 30 where the permeable increasing film 70 is not formed becomes relatively small, and the tube portion 30. It is not easy to suppress the overall temperature rise. On the other hand, when the values of θ ₁ and θ ₂ described above exceed 55 degrees, the surface area of the outer surface of the tube portion 30 where the permeable membrane 70 is not formed becomes relatively large, It is not easy to improve the light utilization efficiency.
From the above viewpoint, in the projector 1000 according to the first embodiment, the values of θ ₁ and θ ₂ are 40 degrees <θ ₁ ≦ 55 degrees and 40 degrees <θ ₂ ≦ 55 degrees.

In the projector 1000 according to the first embodiment, the arc tube 20 is an arc tube that produces a lens effect by the inner surface and the outer surface of the bulb portion 30, and one sealing portion side area A ₁ (on the ellipsoidal reflector 10 side). Since the apparent light emission point of the light ray passing through the sealing portion side region does not exist in the virtual region R, the transmissive film 70 is not formed at a position where light that is difficult to use passes. This eliminates the need for forming a permeable film at the position where light that is difficult to use passes through during film formation, thus facilitating film design and film formation work, and at the same time the one sealing portion side region A. Therefore, it is possible to suppress the decrease in the light utilization efficiency due to the fact that the light-transmitting film 70 is not formed on ₁ .

Further, in the projector 1000 of embodiment 1, the light emitting point of the apparent beam passing through the central area A ₂ is due to the presence in the virtual area R, transmission increasing film at a position passing through the available light 70 Will be formed. As a result, the projector is excellent in terms of improving the light utilization efficiency.

In the projector 1000 of embodiment 1, since the angle formed by the plane perpendicular to the normal line N to the illumination optical axis 100ax for the outer surface of tube portion 30 in the central region A ₂ (xy plane) omega is less than 45 degrees , by replacing the attachment angle of the coating material, the deposition angle becomes the transmission increasing film 70 only in the central region a ₂ of tube portion 30 to be 45 degrees or less is formed, a problem that the film properties is hardly out occurs There is nothing. In addition, since a coating substance with little angle dependency is not used and the number of films is not increased, the manufacturing cost is not increased and the film forming operation is not complicated. As a result, the projector 1000 according to the first embodiment includes the arc tube having excellent film characteristics, and does not increase the manufacturing cost or complicate the film forming operation.

In the projector 1000 of embodiment 1, the intensity of light emitted from the central region A ₂ is 20% or more with respect to the intensity of the high light of the most intensity of the light emitted from the tube spherical portion 30. As a result, the light-transmitting film 70 is formed in a portion where the light intensity is relatively high, so that the projector is excellent in improving the light utilization efficiency.

In the projector 1000 according to the first embodiment, the intensity of light emitted from _one sealing portion side region A ₁ and the other sealing portion side region A ₃ is light emitted from the tube portion 30. Is less than 20% of the intensity of light having the highest intensity. As a result, the light-transmitting film 70 is not formed in the portion where the light intensity is relatively low, and it is not necessary to form the light-transmitting film in the portion where the light intensity is relatively low when forming the film. Therefore, it becomes easy film design and film forming operation, the light use efficiency due to that one of the transmission increasing film 70 in the sealing portion side regions a ₁ and the other sealing portion side region a ₃ is not formed Can be suppressed as much as possible.

[Embodiment 2]
FIG. 9 is a diagram for explaining the light source device 110B in the projector 1002 according to the second embodiment. FIG. 9A is a diagram schematically showing the light source device 110B, FIG. 9B is a side view of the tube portion 30, and FIG. 9C is a perspective view of the tube portion 30. FIG. In FIG. 9C, the secondary mirror 60 is not shown in order to explain in detail how the permeable membrane 72 is formed on the outer surface of the tube portion 30.

  9, the same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  A projector 1002 (not shown) according to the second embodiment basically has a configuration similar to that of the projector 1000 according to the first embodiment, but the configuration of the light source device and the position where the transmissive film is formed are the same as those in the first embodiment. 1 is different from the projector 1000 according to the first embodiment.

  That is, in the projector 1002 according to the second embodiment, the light source device 110B includes an ellipsoidal reflector 10B as a reflector, and an arc tube 20 having a light emission center near the first focal point of the ellipsoidal reflector 10B, as shown in FIG. And a secondary mirror 60 as a reflecting means. The light source device 110B emits a light beam having the illumination optical axis 100ax as a central axis.

  The ellipsoidal reflector 10B has the same configuration as the ellipsoidal reflector 10 described in the first embodiment. As shown in FIG. 9A, the sealing portion (one sealing portion) of the arc tube 20 is provided. It has the opening part 12B for inserting and fixing 40, and the reflective concave surface 14B which reflects the light radiated | emitted from the arc_tube | light_emitting_tube 20 toward the 2nd focus position. The ellipsoidal reflector 10B is fixed to the sealing portion 40 of the arc tube 20 with an inorganic adhesive such as cement filled in the opening 12 of the ellipsoidal reflector 10B.

For example, crystallized glass, alumina (Al ₂ O ₃ ), or the like can be suitably used as the material of the base material that constitutes the reflective concave surface 14B. On the inner surface of the reflective concave surface 14B, for example, a visible light reflecting layer made of a dielectric multilayer film of titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ) is formed.

  The secondary mirror 60 is a reflecting means that covers approximately half of the bulb portion 30 and is disposed to face the reflective concave surface 14B of the elliptical reflector 10B, and is a sealing portion (the other sealing portion) 50 of the arc tube 20. And a reflective concave surface 64 that reflects the light emitted from the arc tube 20 toward the illuminated area toward the arc tube 20. The light reflected by the secondary mirror 60 passes through the arc tube 20 and enters the ellipsoidal reflector 10B. The secondary mirror 60 is fixed to the sealing portion 50 of the arc tube 20 with an inorganic adhesive such as cement filled in the opening 62 of the secondary mirror 60.

As a material constituting the reflective concave surface 64, for example, translucent alumina is used. Thereby, the heat dissipation in the secondary mirror 60 can be improved. In addition to alumina, materials such as quartz glass, sapphire, and ruby may be used.
On the inner surface of the reflective concave surface 64, for example, a reflective layer made of a dielectric multilayer film of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ) is formed.

  Since the arc tube 20 is the same as that described in the first embodiment, detailed description thereof is omitted.

In the projector 1002 according to the second embodiment, a portion of the central area A ₂ that is covered with the secondary mirror 60 is formed with a transmissive film 72 and is covered with the secondary mirror 60 in the central area A _2. The permeable membrane 72 is not formed in the part that is not. Further, for one sealing portion side region A ₁ and the other sealing portion side region A _3, similarly to the case of the first embodiment, transmission increasing film 72 is not formed.

As with the case of the permeable film 70 described in the first embodiment, the permeable film 72 includes a multilayer film of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ). Compared with the case where 72 is not formed, the light transmittance of 400 nm to 700 nm is increased.

  As a method for forming the permeable membrane 72 on the outer surface of the tube portion 30, the method described in the first embodiment can be used.

As described above, the projector 1002 according to the second embodiment differs from the projector 1000 according to the first embodiment in the configuration of the light source device and the formation position of the permeable film, but differs from the projector 1000 according to the first embodiment. Similarly, not formed with transmission increasing film 72 on one of the sealing portion side region a ₁ and the other sealing portion side area a ₃ on the outer surface of the tube spherical portion 30, the center of the outer surface of the tube spherical portion 30 because it is formed transmission increasing film 72 in the part of the region a _2, while improving the light utilization efficiency, can be the temperature of the tube spherical portion 30 can be inhibited from being totally higher In addition, it is possible to suppress a decrease in the lifetime of the light source device 110B, and further, the projector does not require complicated film design / film formation work.

In the projector 1002 according to the second embodiment, the light source device 110B is disposed on the other sealing portion 50 side of the arc tube 20 so as to cover the outer surface of the tube portion 30 on the illuminated area side. The secondary mirror 60 is further reflected to reflect the light toward the arc tube 20. As a result, it is possible to effectively use light that has been emitted from the arc tube 20 toward the illuminated region and that has not been effectively used. For this reason, it is possible to increase the brightness of the projector 1002.
Further, it is not necessary to set the size of the ellipsoidal reflector 10B so as to cover the end of the arc tube 20 to be illuminated, and the ellipsoidal reflector 10B can be reduced in size, and as a result. A compact projector can be realized. Furthermore, since the ellipsoidal reflector 10B can be miniaturized, the size of the optical element arranged in the latter stage of the optical path can be reduced, so that the projector becomes more compact.

By the way, by arranging the secondary mirror 60 in the sealing portion 50 of the arc tube 20, it becomes possible to improve the light utilization efficiency and to reduce the size of the ellipsoidal reflector 10B. However, since approximately half of the bulb portion 30 is covered by the secondary mirror 60, the projector 1002 in which the secondary mirror 60 is disposed in the sealing portion 50 of the arc tube 20 is realized. There is a tendency that the temperature of the tube portion 30 tends to be higher than that of a projector in which such a secondary mirror is not provided.
Since the present invention can suppress the overall temperature of the tube portion 30 from becoming high as described above, the secondary mirror 60 is provided on the sealing portion 50 of the arc tube 20 as described above. This is particularly effective for the projector disposed.

In the projector 1002 in which the secondary mirror 60 is disposed in the sealing portion 50 of the arc tube 20, the light reflected by the secondary mirror 60 out of the light emitted from the arc tube 20 is emitted from the arc tube 20. Then, the light passes through the outer surface of the tube portion 30 a plurality of times before being reflected by the secondary mirror 60 and again passing through the arc tube 20 and entering the ellipsoidal reflector 10B.
Since the present invention makes it possible to increase the transmittance of visible light when passing through the outer surface of the bulb portion 30 as described above, the secondary mirror 60 is provided in the sealing portion 50 of the arc tube 20 in this way. This is particularly effective for a projector in which is provided.

  Further, in the projector 1002 in which the secondary mirror 60 is disposed in the sealing portion 50 of the arc tube 20, since a space is formed between the bulb portion 30 and the secondary mirror 60, the bulb portion 30 is effectively used. It is possible to cool the arc tube 20 and extend the life of the arc tube 20.

In the projector 1002 according to embodiment 2, where is omitted according to the illustrated, substantially intermediate position P of the one sealing portion side region A ₁ and the central region A ₂ of the boundary portion and a pair of electrodes 42 and 52 Since the straight line passing through the boundary passes through the boundary between the portion covered by the secondary mirror 60 on the outer surface of the tube portion 30 and the portion not covered by the secondary mirror 60 on the outer surface of the tube portion 30, the light utilization efficiency is Although it is slightly lowered, it is possible to further suppress the overall temperature rise of the tube portion 30.

  The projector 1002 according to the second embodiment has the same configuration as that of the projector 1000 according to the first embodiment except that the configuration of the light source device and the formation position of the permeable film are different. Therefore, the projector 1000 according to the first embodiment. Among the effects possessed, the corresponding effect is maintained as it is.

[Embodiment 3]
FIG. 10 is a view for explaining the light source device 110C in the projector 1002 according to the third embodiment. FIG. 10A is a diagram schematically illustrating the light source device 110 </ b> C, FIG. 10B is a side view of the tube portion 30, and FIG. 10C is a perspective view of the tube portion 30.
10, the same members as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  A projector 1004 (not shown) according to the third embodiment basically has a configuration similar to that of the projector 1000 according to the first embodiment, but the formation position of the permeable film is the projector 1000 according to the first embodiment. Is different.

That is, in the projector 1004 according to the third embodiment, the area including the apex portion 34 of the lower side of the gravity at the outer surface of the inner tube portion 30 of the center region A _2, are formed transmission increasing film 74 , the region including the upper apex portion 32 with respect to one sealing portion side region a ₁ and the other sealing portion side region a ₃ and gravity at the outer surface of the inner tube portion 30 of the center region a _2, increasing The permeable film 74 is not formed.

As with the case of the permeable film 70 described in the first embodiment, the permeable film 74 is composed of a multilayer film of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ). Compared with the case where 74 is not formed, the light transmittance of 400 nm to 700 nm is increased.

  As a method for forming the permeable membrane 74 on the outer surface of the tube portion 30, the method described in the first embodiment can be used.

As described above, the projector 1004 according to the third embodiment differs from the projector 1000 according to the first embodiment in the formation position of the permeable film, but as in the case of the projector 1000 according to the first embodiment, the tube The one of the sealing portion side region A ₁ and the other sealing portion side region A ₃ on the outer surface of the portion 30 is not formed with the permeable film 74, and one of the central regions A _{2 on} the outer surface of the tube portion 30. Since the light-transmitting film 74 is formed on the part, it is possible to suppress the overall temperature of the tube part 30 from being increased while improving the light utilization efficiency, and the light source device It is possible to suppress a decrease in the lifetime of 110C, and furthermore, the projector does not require complicated film design / film formation work.

  In addition, according to the projector 1004 according to the third embodiment, since the permeable film 74 is not formed in the region including the upper apex portion 32 with respect to the gravity on the outer surface of the tube portion 30, Since it becomes possible to suppress that temperature becomes high as a whole, it can suppress that the temperature of the upper vertex part 32 in a tube part becomes high, and the upper apex part in a tube part It is possible to suppress the occurrence of local swelling or whitening at 32. As a result, it is possible to suppress a decrease in the lifetime of the light source device 110C.

  Further, according to the projector 1004 according to the third embodiment, since the permeable film 74 is formed in the region including the lower apex portion 34 with respect to the gravity on the outer surface of the tube portion 30, the light as a whole It becomes possible to improve utilization efficiency.

  Since the projector 1004 according to the third embodiment has the same configuration as that of the projector 1000 according to the first embodiment except that the formation position of the permeable film is different, among the effects of the projector 1000 according to the first embodiment. Has the relevant effect as it is.

  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.

(1) In the projectors 1000 to 1004 according to the above-described embodiments, as shown in FIG. 8, the reflectance of light of 400 nm to 700 nm is lower than the reflectance of light in other wavelength regions as the transmissive film. Although the light-transmitting films 70 to 74 having the characteristics, that is, the characteristics of increasing the light transmittance of 400 nm to 700 nm as compared with the case where the light-transmitting film 70 is not formed are used, the present invention is not limited to this. is not.
FIG. 11 is a diagram showing the spectral characteristics of the enhanced transmission film 76 in the modification. The permeable increasing film 76 is composed of a multilayer film of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), as shown in FIG. 11, compared with the portion where the permeable increasing film 76 is not formed. Therefore, the light transmittance of 400 nm to 1500 nm is increased.
As shown in the modified example of FIG. 11, a thickening film 76 having a characteristic of increasing the light transmittance of 400 nm to 1500 nm as compared with the portion where the thickening film 76 is not formed may be used. . In this case, it becomes possible to improve the light use efficiency of visible light emitted from the central region A ₂ on the outer surface of the tube spherical portion 30, the light of some wavelength region in the infrared region that is continuous with visible It is possible to suppress the light reflected from the outer surface of the tube portion 30 (the central region A ₂ in the tube portion 30) and converted into heat. As a result, there is an effect that it is possible to suppress the overall temperature rise of the tube portion 30 while improving the light utilization efficiency.

(2) In the projector 1004 according to the third embodiment, the surface area of the tube portion 30 of the central region A _{2 where} the permeable increasing film 74 is formed is the portion where the permeable increasing film 74 is not formed. The case where the permeable membrane 74 is formed on the outer surface of the tube portion 30 so as to be larger than the surface area of the tube portion 30 has been described as an example, but the present invention is not limited to this. . In the central region A ₂ , the surface area of the tube bulb portion 30 in the portion where the permeable membrane 74 is formed is substantially the same as the surface area of the bulb portion 30 in the portion where the permeable membrane 74 is not formed. A permeable membrane 74 may be formed on the outer surface of the tube portion 30. That is, the boundary surface of the virtual plane including the illumination optical axis 100ax and the x-axis, the lower (y (-) side) than the virtual plane is formed with transmission increasing film 74 in the central region A ₂ of the virtual may be configured not formed transmission increasing film 74 in the central region a ₂ of the upper (y (+) side) than the plane.

(3) In the projectors 1000 and 1004 according to the first and third embodiments, the light source devices 110 and 110C in which the secondary mirror 60 is not disposed in the arc tube 20 are used as the light source devices. However, the present invention is not limited, and a light source device in which a secondary mirror is arranged like the projector 1002 according to the second embodiment may be used.

(4) In the projectors 1000 to 1004 according to the above embodiments, the ellipsoidal reflector is used as the reflector. However, the present invention is not limited to this, and a parabolic reflector can also be preferably used.

(5) In projectors 1000 to 1004 according to the above embodiments, a lens integrator optical system including a lens array is used as the light uniformizing optical system. However, the present invention is not limited to this, and the rod member is used. A rod integrator optical system made of can also be preferably used.

(6) The projectors 1000 to 1004 according to the above embodiments are transmissive projectors, but the present invention is not limited to this. The present invention can also be applied to a reflection type projector. Here, “transmission type” means that an electro-optic modulation device as a light modulation means, such as a transmission type liquid crystal device, transmits light, and “reflection type” This means that an electro-optic modulation device as a light modulation means, such as a reflective liquid crystal device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(7) In the projectors 1000 to 1004 according to the above-described embodiments, the projector using the three liquid crystal devices 400R, 400G, and 400B has been described as an example. However, the present invention is not limited to this, and The present invention can also be applied to a projector using two, four, or four or more liquid crystal devices.

(8) In the projectors 1000 to 1004 according to the above embodiments, the liquid crystal device is used as the electro-optic modulation device, but the present invention is not limited to this. In general, the electro-optic modulation device may be any device that modulates incident light in accordance with image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

(9) The present invention can be applied both when the projector is used in a so-called stationary state and when the projector is used in a so-called ceiling state.

(10) The present invention is applied to a rear projection projector that projects from a side opposite to the side that observes the projected image, even when applied to a front projection projector that projects from the side that observes the projected image. Is also possible.

FIG. 3 shows an optical system of the projector 1000 according to the first embodiment. The figure shown in order to demonstrate the light source device 110. FIG. The conceptual diagram shown in order to demonstrate the formation position of each area | region in the outer surface of the tube part 30, and the permeation-enhancing film | membrane 70. FIG. The conceptual diagram shown in order to demonstrate the formation position of each area | region in the outer surface of the tube part 30, and the permeation-enhancing film | membrane 70. FIG. The conceptual diagram shown in order to demonstrate the formation position of each area | region in the outer surface of the tube part 30, and the permeation-enhancing film | membrane 70. FIG. The conceptual diagram shown in order to demonstrate the formation position of each area | region in the outer surface of the tube part 30, and the permeation-enhancing film | membrane 70. FIG. The figure which shows the light distribution characteristic of the light radiated | emitted from the tube part. The figure which shows the spectral characteristics of the permeation-enhancing film. FIG. 6 is a diagram for explaining a light source device 110B in a projector 1002 according to a second embodiment. FIG. 10 is a view for explaining a light source device 110C in a projector 1004 according to a third embodiment. The figure which shows the spectral characteristics of the permeation | transmission film | membrane 76 in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10B ... Ellipsoidal reflector, 12, 12B ... Opening part, 14, 14B ... Reflective concave surface, 20 ... Light emission tube, 30 ... Tube part, 32 ... Upper vertex part, 34 ... Lower vertex part, 40, DESCRIPTION OF SYMBOLS 50 ... Sealing part, 42, 52 ... Electrode, 44, 54 ... Metal foil, 46, 56 ... Lead wire, 60 ... Secondary mirror, 62 ... Opening part, 64 ... Reflective concave surface, 70, 72, 74 ... Thickening transmission film , 90 ... concave lens, 100 ... illumination device, 100ax ... illumination optical axis, 110, 110B, 110C ... light source device, 120 ... first lens array, 122 ... first small lens, 130 ... second lens array, 132 ... second Small lens, 140 ... polarization conversion element, 150 ... superposition lens, 200 ... color separation light guide optical system, 210, 220 ... dichroic mirror, 230, 240, 250 ... reflection mirror, 260 ... incident side lens, 270 ... relay Lens, 300R, 300G, 300B ... condenser lens, 400R, 400G, 400B ... liquid crystal device, 500 ... cross dichroic prism 600 ... projection optical system, 1000, 1002 ... projector, A 1 _... one sealing portion side region, A ₂ ... central region, A ₃ ... other sealing portion side region, b _{1 to} b ₄ ... boundary portion, c ₁ ... apparent light emitting point of light beam H ₁ passing through central region A ₂ , c ₂ ... one The apparent light emission point of the light beam H ₂ passing through the sealing portion side region A ₁ , H ₁ ... the light beam passing through the central region A ₂ , H ₂ ... the light beam passing through one sealing portion side region A ₁ , L _{1 to} L ₄ ... a straight line passing through the boundary portions b _{1 to} b ₄ and the substantially intermediate position P of the pair of electrodes, N ... a normal to the outer surface of the tube portion, P ... an approximately intermediate position of the pair of electrodes, R ... a pair of electrodes Cylindrical virtual region included inside, SCR ... screen, _{1 ...} an angle between the straight line L ₃ and the illumination optical axis, the angle between theta _{2 ...} straight lines L ₁ and the illumination optical axis, omega ... and normal to the outer surface of the axis parallel to the tube spherical portion scattering direction of the coating material Angle

Claims (12)

A tube bulb containing a pair of electrodes arranged along the illumination optical axis, an arc tube having one sealing portion and the other sealing portion extending on both sides of the bulb portion, and the one sealing portion A light source device having a reflector disposed on the side and reflecting light from the arc tube toward the illuminated region side;
An electro-optic modulator that modulates illumination light flux from the light source device according to image information;
In a projector including a projection optical system that projects light modulated by the electro-optic modulation device,
The outer surface of the tube part is provided with one sealing part side region located on the one sealing part side, the other sealing part side region located on the other sealing part side, and the one sealing part. When divided into three regions, a central region located between the stop portion side region and the other sealing portion side region,
In the central region on the outer surface of the tube portion, a permeable membrane is formed,
In the one sealing part side region and the other sealing part side region on the outer surface of the tube part, the permeable membrane is not formed,
The projector according to claim 1, wherein the light-transmitting film has a property of increasing light transmittance at least in a visible region as compared with a portion where the light-transmitting film is not formed. The projector according to claim 1, wherein
The projector according to claim 1, wherein the transmissive film has a characteristic of increasing a light transmittance of 400 nm to 700 nm as compared with a portion where the transmissive film is not formed. The projector according to claim 1, wherein
The projector according to claim 1, wherein the transmissive film has a characteristic of increasing a light transmittance of 400 nm to 1500 nm as compared with a portion where the transmissive film is not formed. The projector according to any one of claims 1 to 3,
The projector according to claim 1, wherein the permeable film is formed of a multilayer film of Ta ₂ O ₅ and SiO ₂ . The projector according to any one of claims 1 to 4,
The arc tube is an arc tube that produces a lens effect by an inner surface and an outer surface of the bulb portion,
An apparent light emitting point when a light ray passing through the one sealing portion side region of the light emitted from the outer surface of the tube portion is extended toward the illumination optical axis is the internal electrode of the pair of electrodes. A projector characterized by not existing in a cylindrical virtual region including the projector. The projector according to any one of claims 1 to 4,
When the angle between the normal to the outer surface of the tube portion in the central region and the plane perpendicular to the illumination optical axis is ω,
A projector, wherein ω ≦ 45 degrees. The projector according to any one of claims 1 to 4,
The projector according to claim 1, wherein the intensity of light emitted from the central region is 20% or more with respect to the intensity of light having the highest intensity among the light emitted from the tube portion. The projector according to any one of claims 1 to 4,
When the boundary portion of the other of the sealing portion side region and the central region and the straight line passing through the substantially intermediate position of the pair of electrodes, the angle at which the illumination optical axis forms of the light source device and theta _1,
40 ° <θ ₁ ≦ 55 °. The projector according to any one of claims 1 to 4,
A straight line passing through the substantially intermediate position of the pair of electrodes and the boundary portion of the one sealing portion side region of and the central region, when the angle of the illumination optical axis forms of the light source device was theta _2,
40 ° <θ ₂ ≦ 55 °. The projector according to any one of claims 1 to 4,
The light source device is
A secondary mirror that is disposed on the other sealing portion side of the arc tube so as to cover an outer surface of the bulb portion on the illuminated area side, and reflects light from the arc tube toward the arc tube A projector comprising: The projector according to claim 10, wherein
A straight line passing through the boundary between the one sealing portion side region and the central region and a substantially intermediate position between the pair of electrodes is a portion covered with the secondary mirror on the outer surface of the tube portion and the tube bulb. A projector that passes through a boundary portion with a portion that is not covered with the secondary mirror on an outer surface of the portion. The projector according to any one of claims 1 to 11,
In the region including the apex portion on the lower side with respect to gravity on the outer surface of the tube portion, the permeable membrane is formed,
The projector according to claim 1, wherein the permeable membrane is not formed in a region including an upper apex portion with respect to gravity on the outer surface of the tube portion.