JP2008070618A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of restraining the temperature of a light tube part from entirely getting high while improving the efficiency of using light, and restraining service life of a light source device from being shortened. <P>SOLUTION: The projector is equipped with: the light source device 110 which has a light emitting tube 20 having the light tube part 30 and a pair of sealing parts 40 and 50 extended to both sides of the light tube part, and an ellipsoidal reflector 10 reflecting light from the light emitting tube 20 to the side of an area to be illuminated; a liquid crystal device which modulates illuminating luminous flux from the light source device according to image information; and a projection optical system which projects the light modulated by the liquid crystal device. An increased transmittance coating 70 having characteristic that light transmittance in a visible region and in a wavelength region which is a part of an infrared region continuing to the visible region is made higher than in a part where the increased transmittance coating 70 is not formed is formed in an area including a top part 32 on the upside with respect to gravity on the outer surface of the light tube 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 light is not taken into consideration, the reflectance of the light in the other wavelength range becomes relatively high, and a part of the light in the other wavelength range reflected by the antireflection film is converted into heat. As a result, the temperature of the tube portion is increased overall. 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.

  As a means for solving the first problem among the above two problems, the air flow is increased by increasing the number of rotations 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 of the two problems described above, 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”.

  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. And it aims at providing the projector which can suppress the fall of the lifetime of a light source device.

  The projector according to the present invention includes an arc tube having a tube bulb portion including a pair of electrodes arranged along an illumination optical axis, a pair of sealing portions extending on both sides of the tube bulb portion, and one of the arc tubes in the arc tube. A light source device that is disposed on the sealing portion side and has a reflector that reflects light from the arc tube toward the illuminated region side, and electro-optic that modulates the illumination light beam from the light source device according to image information In the projector including the modulation device and the projection optical system that projects the light modulated by the electro-optic modulation device, the region including the vertex portion on the upper side with respect to the gravity on the outer surface of the tube portion has a transmissive film And the light-transmitting film has a characteristic of increasing the light transmittance in the visible region and a part of the wavelength region in the infrared region that is continuous to the visible region, compared to the portion where the film is not formed. It is characterized by having

  For this reason, according to the projector of the present invention, since the above-described permeable increasing film is formed in the region including the upper apex portion with respect to the gravity on the outer surface of the tube portion, It is possible to suppress light in a part of the wavelength region of the outer region from being reflected by the outer surface of the tube portion and converted into heat. As a result, 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, it is possible to suppress the overall temperature of the tube portion from increasing. It becomes.

  Further, according to the projector of the present invention, since the above-described permeable membrane is formed in a region including the upper apex portion with respect to gravity on the outer surface of the tube portion, the temperature of the upper apex portion in the tube portion is reduced. It is possible to suppress the increase in the height, and it is possible to suppress the occurrence of local swelling or whitening at the upper apex portion of the bulb portion. 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, since the above-described permeable membrane is formed in the region including the upper apex portion with respect to the gravity on the outer surface of the tube portion, the upper apex portion in the tube portion It is possible to increase the transmittance of visible light when passing through the outer surface of the glass, and 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. Projector.

  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.

  With this configuration, it is possible to improve the light use efficiency of visible light emitted from the upper apex portion of the bulb portion.

  In the projector according to the aspect of the invention, the other permeable film may be formed in a region including the lower apex portion with respect to gravity on the outer surface of the tube portion, and the other permeable film may be the other permeable film. It is preferable to have a characteristic of increasing the light transmittance in the visible region as compared with the portion where the additional transmission film is not formed.

  With this configuration, it is possible to improve the light use efficiency of visible light emitted from the lower apex portion of the tube portion.

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

  With this configuration, it is possible to improve the light use efficiency of visible light emitted from the lower apex portion of the tube portion.

In the projector according to the aspect of the invention, it is preferable that at least one of the permeable film and the other permeable film is formed of a multilayer film of Ta ₂ O ₅ and SiO ₂ .

  With this configuration, it becomes possible to improve the heat resistance of the permeable membrane and / or other permeable membranes, and the surface of the bulb portion of the arc tube exposed to extremely high temperatures is good for a long period of time. Therefore, it is possible to maintain a good increased transmission characteristic.

In the projector according to the aspect of the invention, it is preferable that the increasing transmission film is formed of a multilayer film of Ta ₂ O ₅ and SiO ₂ having a thickness of 10 to 30 layers.

When the number of layers of the permeable film is less than 10 layers, the light transmittance in the visible region and a part of the wavelength region in the infrared region that is continuous with the visible region is higher than the portion where the permeable film is not formed. It is not easy to realize a permeable membrane having On the other hand, when the number of layers of the permeable membrane is more than 30, it is not preferable because the manufacturing cost increases and the productivity decreases.
From the above viewpoint, it is preferable that the permeable membrane is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ of 10 layers or more and 30 layers or less.

In the projector according to the aspect of the invention, it is preferable that the other permeable increasing film is formed of a multilayer film of Ta ₂ O ₅ and SiO ₂ and having 5 or more layers and less than 10 layers.

When the number of layers of the other permeable membranes is less than five, it is possible to realize a permeable membrane having the characteristic of increasing the light transmittance in the visible region as compared with the portion where the other permeable membranes are not formed. It will not be easy. On the other hand, when the number of layers of the other permeable membrane is 10 or more, it is not preferable because the manufacturing cost increases and the productivity decreases.
From the above viewpoint, it is preferable that the other permeable membrane is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ and having 5 or more layers and less than 10 layers.

  In the projector according to the aspect of the invention, a surface area of the tube portion of the portion where the permeable film is formed may be a portion where the permeable film is not formed or a portion where the other permeable film is formed. It is preferable that the permeable membrane is formed on the outer surface of the tube portion so as to be larger than the surface area of the sphere portion.

  With such a configuration, it is possible to improve the light utilization efficiency while suppressing the overall temperature rise of the tube portion and the life of the light source device.

  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 reflecting means for reflecting 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 the reflecting means in the sealing portion of the arc tube, thereby realizing a high-intensity and compact projector. However, since almost half of the bulb portion is covered with the reflecting means, the projector in which the reflecting means is disposed at the sealing portion of the arc tube is provided with such reflecting means. 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 tube bulb portion from being increased, and thus the reflecting means is disposed in the sealing portion of the arc tube as described above. This is particularly effective for projectors.

In the projector in which the reflecting means is disposed at the sealing portion of the arc tube, the light reflected from the reflecting means out of the light emitted from the arc tube is reflected by the reflecting means after being emitted from the arc tube. Then, the light passes through the outer surface of the bulb 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 reflection means is disposed in the sealing portion of the arc tube as described above. This is especially effective for projectors.

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

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

[Embodiment]
FIG. 1 is a diagram illustrating an optical system of a projector 1000 according to the 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. 2B and 2C, in order to explain in detail how the permeable membrane 70 and the other permeable membrane 80 are formed on the outer surface of the tube portion 30, The secondary mirror 60 is not shown.

  FIG. 3 is a diagram showing the spectral characteristics of the permeable membrane 70 and other permeable membranes 80. FIG. 3 shows spectral characteristics of the permeable film 70 and other permeable films 80, and also shows spectral characteristics when the permeable film 70 and other permeable films 80 are 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 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 illuminated area. A color separation light guide optical system 200, and three liquid crystal devices 400R, 400G, and 400B as electro-optic modulation devices that modulate each of the three color lights separated by the color separation light guide optical system 200 according to image information; 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. Projector.

  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, an arc tube 20 having a light emission center near the first focal point of the ellipsoidal reflector 10, and a reflecting means. And a secondary mirror 60. 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. 2, a permeable increasing film 70 is formed in a region including the apex portion 32 above the gravity on the outer surface of the tube portion 30. The increased transmission film 70 is composed of a multilayer film (for example, 20 layers) of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), and reflects light of 400 nm to 1500 nm as shown in FIG. The rate is lower than the reflectance of light in other wavelength regions. That is, the light-transmitting film 70 has a characteristic of increasing the light transmittance in the visible region and a part of the wavelength region in the infrared region that is continuous to the visible region, as compared with the portion where the film 130 is not formed.

In the region including the lower apex portion 34 with respect to gravity on the outer surface of the tube portion 30, another permeable increasing film 80 is formed as shown in FIG. 2. The other permeable film 80 is composed of a multilayer film (for example, eight layers) of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ). As shown in FIG. 3, light having a wavelength of 400 nm to 700 nm is used. Has a lower characteristic than the reflectance of light in other wavelength regions. That is, the other permeable increasing film 80 has a characteristic of increasing the light transmittance in the visible region as compared with the portion where the other increasing permeable film 80 is not formed.

  That is, the transmissive film 70 is formed on the outer surface of the tube portion 30 above (y (+) side) the virtual plane including the illumination optical axis 100ax and the x-axis as a boundary plane. Another permeable membrane 80 is formed on the outer surface of the tube portion 30 below (y (−) side) the virtual plane.

As a method for forming the permeable film 70 and the other permeable film 80 on the outer surface of the tube portion 30, various methods such as an evaporation method, a dipping method, an ion plating method, and a sputtering method can be used. For example, a portion (an outer surface of the bulb portion 30 below the imaginary plane (y (−) side)) where the other permeable membrane 80 is formed is covered with a masking tape or the like, and the arc tube 20 is rotated and revolved. By alternately depositing tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), a region including the upper apex portion 32 on the outer surface of the tube portion 30 (above the virtual plane (y (+ The permeable membrane 70 can be formed only on the outer surface) of the tube portion 30 on the side). The method of forming the other permeable membrane 80 is the same as the above method.

  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.

  The secondary mirror 60 is a reflecting means that covers substantially half of the bulb portion 30 and is disposed to face the reflective concave surface 14 of the elliptical reflector 10. The secondary mirror 60 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 10. 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.

  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.

  In the projector 1000 according to the embodiment configured as described above, the above-described permeable increasing film 70 is formed in a region including the upper vertex portion 32 with respect to gravity on the outer surface of the tube portion 30. Therefore, it is possible to suppress light in a part of the wavelength region in the infrared region that is continuous with the visible region from being reflected on the outer surface of the tube portion 30 and converted into heat. As a result, it is possible to suppress the overall temperature of the tube portion 30 from becoming higher compared to the case where an antireflection film is formed on the entire outer surface of the tube portion as in the conventional light source device. It becomes possible.

  Further, according to the projector 1000 according to the embodiment, since the above-described permeable increasing film 70 is formed in the region including the upper vertex portion 32 with respect to the gravity on the outer surface of the tube portion 30, It becomes possible to suppress the temperature of the upper vertex portion 32 from becoming high, and to suppress the occurrence of local swelling or whitening in the upper vertex portion 32 of the tube portion 30. It becomes possible. 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 embodiment, since the above-described permeable increasing film 70 is formed in the region including the upper vertex portion 32 with respect to the gravity on the outer surface of the tube portion 30, the tube portion The transmittance of visible light when passing through the outer surface of the upper apex portion 32 at 30 can be increased, and the light utilization efficiency as a whole can be improved.

  Therefore, the projector 1000 according to the embodiment can suppress the overall temperature of the tube portion 30 from being increased while improving the light utilization efficiency, and the life of the light source device 110 can be reduced. The projector can suppress the decrease.

  In the projector 1000 according to the embodiment, the transmissive film 70 has a characteristic of increasing the light transmittance of 400 nm to 1500 nm as compared with a portion where the transmissive film 70 is not formed. Thereby, it becomes possible to improve the light use efficiency of visible light radiated | emitted from the upper vertex part 32 of the tube part 30. FIG.

  In the projector 1000 according to the embodiment, since the other permeable film 80 described above 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 tube portion It is possible to improve the light use efficiency of the visible light emitted from the lower apex portion 34 of 30.

  In the projector 1000 according to the embodiment, the other transmissive film 80 has a characteristic of increasing the light transmittance of 400 nm to 700 nm as compared with a portion where the other transmissive film 80 is not formed. Thereby, it becomes possible to improve the light use efficiency of visible light radiated | emitted from the lower vertex part 34 of the tube part 30. FIG.

In the projector 1000 according to the embodiment, the permeable film 70 and the other permeable film 80 are composed of a multilayer film of Ta ₂ O ₅ and SiO _2, and thus the permeable film 70 and the other permeable film. It becomes possible to improve the heat resistance of 80, and even on the surface of the bulb portion 30 of the arc tube 20 exposed to an extremely high temperature, it is possible to maintain good increased transmission characteristics over a long period of time.

When the number of layers of the transmissive film 70 is less than 10, the light transmittance in the visible region and a part of the wavelength region in the infrared region continuous to the visible region is higher than that in the portion where the permeable film 70 is not formed. It is not easy to realize a permeable membrane having such characteristics. On the other hand, when the number of layers of the permeable membrane 70 is more than 30, it is not preferable because the manufacturing cost increases and the productivity decreases.
From the above viewpoint, in the projector 1000 according to the embodiment, the transmissive film 70 is formed of a multilayer film including, for example, 20 layers of Ta ₂ O ₅ and SiO ₂ .

When the number of layers of the other permeable films 80 is less than five, a permeable film having a characteristic of increasing the light transmittance in the visible region as compared with the portion where the other permeable films 80 are not formed is realized. Is no longer easy. On the other hand, when the number of layers of the other permeable membrane 80 is 10 or more, it is not preferable because the manufacturing cost increases and the productivity decreases.
From the above viewpoint, in the projector 1000 according to the embodiment, the other transmissive film 80 is configured by a multilayer film including, for example, eight layers of Ta ₂ O ₅ and SiO ₂ .

In the projector 1000 according to the embodiment, the light source device 110 further includes a sub mirror 60 as a reflecting unit disposed on the sealing unit 50 side so as to cover the outer surface of the tube unit 30 on the illuminated region side. Thereby, since the light radiated from the arc tube 20 to the illuminated area side is reflected by the secondary mirror 60 toward the ellipsoidal reflector 10, it is radiated from the arc tube 20 to the illuminated area side and is effectively used originally. It is possible to effectively use the light that did not exist. For this reason, it is possible to increase the brightness of the projector 1000.
Further, it is not necessary to set the size of the ellipsoidal reflector 10 so as to cover the end of the arc tube 20 to be illuminated, and the ellipsoidal reflector 10 can be reduced in size, as a result. A compact projector can be realized. Furthermore, since the ellipsoidal reflector 10 can be reduced in size, the size of the optical element arranged in the latter stage of the optical path can be reduced, so that a more compact projector can be obtained.

By the way, by disposing 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 10, and to achieve high brightness and compactness. However, since approximately half of the bulb portion 30 is covered by the secondary mirror 60, the projector 1000 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 1000 provided.

In the projector 1000 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 10.
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. The effect is particularly great for the projector 1000 in which is provided.

  Further, in the projector 1000 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.

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

(1) In the projector 1000 according to the above-described embodiment, as shown in FIGS. 2B and 2C, the surface area of the tube portion 30 in the portion where the permeable increasing film 70 is formed has a different increase. The permeable membrane 70 and the other permeable membrane 80 are formed on the outer surface of the tube portion 30 so as to be substantially the same as the surface area of the tube portion 30 where the permeable membrane 80 is formed. Is not limited to this.
FIG. 4 is a view for explaining the permeation increasing film 70a and the other permeation increasing film 80a in the first modification. 4A is a side view of the tube portion 30 in the first modification, and FIG. 4B is a perspective view of the tube portion 30 in the first modification. In FIG. 4, the same members as those in FIGS. 2B and 2C are denoted by the same reference numerals, and detailed description thereof is omitted. The permeable film 70a is composed of a multilayer film (for example, 20 layers) of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), as in the case of the permeable film 70 described in the embodiment. And has a characteristic of increasing the light transmittance of 400 nm to 1500 nm as compared with the portion where the increased transmission film 70a is not formed. The other permeable film 80a is a multilayer film (for example, eight layers) of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), as in the case of the other permeable film 80 described in the embodiment. It has a characteristic of increasing the light transmittance of 400 nm to 700 nm as compared with the portion where the other transmissive film 80a is not formed.
As shown in FIG. 4, in the first modification, the surface area of the tube portion 30 in the portion where the permeable membrane 70a is formed is greater than the surface area of the tube portion 30 in the portion where the other permeable membrane 80a is formed. A permeable increasing film 70a and another permeable increasing film 80a may be formed on the outer surface of the tube portion 30 so as to have a size. Note that when the permeable membrane 70a and the other permeable membrane 80a are formed on the outer surface of the bulb portion 30 as in the first modification, the overall temperature rise of the bulb portion and the life of the light source device are reduced. There is an effect that it is possible to improve the light use efficiency while suppressing the decrease.

(2) In the projector 1000 according to the above embodiment, as shown in FIGS. 2B and 2C, the projector 1000 has a region including the apex portion 34 below the gravity on the outer surface of the tube portion 30. The above-described other permeable membrane 80 is formed, but the present invention is not limited to this.
FIG. 5 is a view for explaining the permeable membrane 70b in the second modification. FIG. 5A is a side view of the tube portion 30 in the second modification, and FIG. 5B is a perspective view of the tube portion 30 in the second modification. In FIG. 5, the same members as those in FIGS. 2B and 2C are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, the permeable film 70b is formed of a multilayer film (for example, 20 layers) of tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ), as in the case of the permeable film 70 described in the embodiment. And has a characteristic of increasing the light transmittance of 400 nm to 1500 nm as compared with the portion where the increased transmission film 70b is not formed.
In the second modification, as shown in FIG. 5, the other permeable membrane 80 may not be formed in the region including the lower apex portion 34 with respect to the gravity on the outer surface of the tube portion 30.

(3) In the projector 1000 according to the above-described embodiment, the light source device 110 in which the sub-mirror 60 as the reflecting means is disposed on the arc tube 20 has been described as an example. However, the present invention is not limited to this. In addition, the present invention can be applied to a projector including a light source device in which a secondary mirror is not provided.

(4) In the projector 1000 according to the above embodiment, an elliptical 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 the projector 1000 according to the above embodiment, the lens integrator optical system including the lens array is used as the light uniformizing optical system. However, the present invention is not limited to this, and the rod including the rod member is used. An integrator optical system can also be preferably used.

(6) The projector 1000 according to the above embodiment is a transmissive projector, 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 projector according to the embodiment, 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 one, two Alternatively, it can be applied to a projector using four or more liquid crystal devices.

(8) In the projector 1000 according to the above-described embodiment, 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 is a diagram showing an optical system of the projector 1000 according to the embodiment. The figure shown in order to demonstrate the light source device 110. FIG. The figure which shows the spectral characteristics of the permeation | transmission film | membrane 70 and the other permeation | transmission film | membrane 80. The figure shown in order to demonstrate the permeation | transmission film | membrane 70a and the other permeation | transmission film | membrane 80a in the modification 1. FIG. The figure shown in order to demonstrate the permeation enhancement film 70b in the modification 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Ellipsoidal reflector, 12 ... Opening part, 14 ... Reflection concave surface, 20 ... Light-emitting tube, 30 ... Tube part, 32 ... Upper vertex part, 34 ... Lower vertex part, 40, 50 ... Sealing part, 42, 52 ... Electrode, 44, 54 ... Metal foil, 46, 56 ... Lead wire, 60 ... Secondary mirror, 62 ... Opening, 64 ... Reflective concave surface, 70, 70a, 70b ... Increase transmission film, 80, 80a ... etc. 90 ... concave lens, 100 ... illumination device, 100ax ... illumination optical axis, 110 ... light source device, 120 ... first lens array, 122 ... first small lens, 130 ... second lens array, 132 ... second Small lens, 140 ... polarization conversion element, 150 ... superimposed lens, 200 ... color separation light guide optical system, 210,220 ... dichroic mirror, 230,240,250 ... reflection mirror, 260 ... incident side lens, 270 ... relay lens, 3 0R, 300G, 300B ... condenser lens, 400R, 400G, 400B ... liquid crystal device, 500 ... cross dichroic prism 600 ... projection optical system, 1000 ... projector, SCR ... screen

Claims (9)

An arc tube having a tube bulb portion including a pair of electrodes arranged along the illumination optical axis and a pair of sealing portions extending on both sides of the tube bulb portion, and disposed on one sealing portion side of the arc tube. A light source device that includes a reflector that reflects the light from the arc tube toward the illuminated area;
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,
In the region including the apex portion on the upper side with respect to gravity on the outer surface of the tube part, a permeable membrane is formed,
The increased transmission film has a characteristic of increasing light transmittance in a visible wavelength region and a part of a wavelength region in an infrared region continuous to the visible region as compared with a portion where the increased transmission film is not formed. projector. 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 claim 1 or 2,
In the region including the apex portion on the lower side with respect to the gravity on the outer surface of the tube portion, another permeable membrane is formed,
The projector according to claim 1, wherein the other permeable increasing film has a characteristic of increasing a light transmittance in a visible region as compared with a portion where the other permeable increasing film is not formed. The projector according to claim 3, wherein
The projector according to claim 1, wherein the other permeable increasing film has a characteristic of increasing a light transmittance of 400 nm to 700 nm as compared with a portion where the other permeable increasing film is not formed. The projector according to any one of claims 1 to 4,
At least one of the permeable increasing film and the other permeable increasing film is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ . The projector according to claim 5, wherein
The projector is characterized in that the permeable film is composed of a multilayer film of Ta ₂ O ₅ and SiO ₂ and having 10 or more layers and 30 or less layers. The projector according to claim 5, wherein
The projector according to claim 1, wherein the other permeable increasing film is formed of a multilayer film of five or more layers of Ta ₂ O ₅ and SiO ₂ and less than ten layers. In the projector according to any one of claims 1 to 7,
The surface area of the tube portion of the portion where the permeable membrane is formed is larger than the surface area of the tube portion of the portion where the permeable membrane is not formed or the portion where the other permeable membrane is formed. The projector is characterized in that the permeable membrane is formed on the outer surface of the tube portion. The projector according to any one of claims 1 to 8,
The light source device is
Reflecting means 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: