JP2010177157A - Lamp unit, and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp unit capable of a suitable temperature controlling of an arc tube. <P>SOLUTION: The lamp unit 2 is provided with an arc tube 11 having a light emitting portion for emitting light, a sub mirror 13 for reflecting light emitted from the light emitting portion, a main mirror 12 for reflecting the light emitted from the light emitting portion and the light reflected from the sub mirror, and a nozzle 14 in which air is passed and which is connected with the sub mirror so that the air between the sub mirror and the light emitting portion may be flowed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lamp unit and a projector, and more particularly, to a technique of a lamp unit having a reflector.

  In a lamp used as a light source of a projector, for example, a discharge lamp such as an extra-high pressure mercury lamp, a reflector (reflecting mirror) that reflects light emitted from an arc tube is used. In order to obtain a bright image efficiently with a projector, a configuration of a lamp unit for improving the utilization efficiency of light emitted from the arc tube has been proposed. For example, a technique has been proposed in which a sub-reflecting mirror is provided in the vicinity of the light emitting portion of the arc tube separately from the reflector that is the main reflecting mirror (see, for example, Patent Documents 1 and 2). After the light reflected by the sub-reflecting mirror passes through the arc tube, it is reflected toward the front side by the main reflecting mirror. This makes it possible to efficiently advance the light emitted from the arc tube to the optical system that uses the light from the lamp unit.

JP 2001-109068 A JP 2008-243640 A

  Lamps used in projectors need to be cooled by cooling air or the like because much of the supplied electric energy becomes heat and becomes high temperature. In the case of a configuration including a sub-reflecting mirror, it is difficult to cool a portion covered by the sub-reflecting mirror on the surface of the light emitting unit. In this case, since the heat radiation which is different between the portion covered by the sub-reflecting mirror and the other portion of the surface of the light emitting portion is exhibited, there arises a problem that it is difficult to appropriately control the temperature of the arc tube. A portion of the arc tube that is not sufficiently cooled may cause the transparent member constituting the arc tube to be crystallized by heat and become cloudy. SUMMARY An advantage of some aspects of the invention is that it provides a lamp unit that enables appropriate temperature control of an arc tube, and a projector having the lamp unit.

  In order to solve the above-described problems and achieve the object, a lamp unit according to the present invention covers an arc tube including a light-emitting unit that emits light and a part of the periphery of the light-emitting unit, and emits from the light-emitting unit. A sub-reflecting mirror that reflects the reflected light, a main reflecting mirror that reflects the light emitted from the light-emitting unit and the light reflected by the sub-reflecting mirror, and between the sub-reflecting mirror and the light-emitting unit by allowing air to pass inside And a nozzle connected to the sub-reflecting mirror to flow the air.

  Since the nozzle is connected to the sub-reflecting mirror and the air between the sub-reflecting mirror and the light emitting unit can flow, the light emitting unit can be sufficiently cooled. Further, if the amount of air passing through the inside of the nozzle is changed, the cooling amount of the arc tube can be controlled. As a result, a lamp unit that enables appropriate temperature control of the arc tube can be obtained. By appropriate temperature control of the arc tube, deterioration of the arc tube can be reduced.

  Moreover, as a preferable aspect of the present invention, it is desirable that an opening is formed in the sub-reflecting mirror, and a connection end of a nozzle is connected to the opening. Air can be sent between the sub-reflecting mirror and the light emitting section through the opening formed in the sub-reflecting mirror, and appropriate temperature control of the arc tube can be performed.

  Further, as a preferred aspect of the present invention, the main reflecting mirror has substantially the same shape as a curved surface obtained by cutting a rotating curved surface obtained by rotating a predetermined curve about the central axis at a predetermined plane. None, the sub-reflecting mirror desirably covers the side opposite to the side where the main reflecting mirror is provided with respect to the light emitting portion. Thereby, a thin lamp unit capable of emitting light efficiently can be obtained. Also, even when the sub-reflecting mirror is used in a state of covering the upper side of the light emitting part and in a state of being used in a state of covering the lower side, the amount of air passing through the inside of the nozzle is changed, By controlling the cooling amount of the arc tube, it is possible to perform cooling in accordance with the use state. In particular, when the sub-reflecting mirror is used in a state of covering the upper side of the light emitting unit, the heat generated in the light emitting unit is trapped between the sub-reflecting mirror and the light emitting unit, and the arc tube is sufficiently cooled. It was difficult. In this case, even when the sub-reflecting mirror is used in a state of covering the upper side of the light emitting unit, the arc tube can be sufficiently cooled by increasing the amount of air passing through the inside of the nozzle. Thereby, the temperature difference by the difference in a use condition can be made small.

  As a preferred embodiment of the present invention, it is desirable that the nozzle is connected to the sub-reflecting mirror from the side opposite to the irradiated surface side. Of the reflecting surface of the sub-reflecting mirror, light is not reflected at the portion where the nozzle is connected, and the light utilization efficiency may be reduced. When the nozzle is connected from the opposite side of the irradiated surface side, the light reflected by the portion to which the nozzle is connected (portion where the opening is formed) may not enter the main reflecting mirror. In such a case, if a nozzle is connected to the sub-reflecting mirror from the side opposite to the irradiated surface side, it is possible to suppress a decrease in light use efficiency due to the connection of the nozzle.

  In a preferred embodiment of the present invention, the main reflecting mirror has substantially the same shape as a rotating curved surface obtained by rotating a predetermined curve around the central axis, and the sub-reflecting mirror covers the light emitting section. It is desirable to cover the irradiation surface side. Thereby, a lamp unit capable of emitting light efficiently can be obtained.

  As a preferred aspect of the present invention, the lamp unit is attachable to and detachable from the projector, and the open end side of the nozzle opposite to the connection end to the sub-reflecting mirror is substantially the same as the attaching and detaching direction of the lamp unit with respect to the projector. It is desirable to be parallel. Since the open end side is substantially parallel to the attaching / detaching direction of the lamp unit, the nozzle is not obstructed when attaching / detaching the lamp unit, and the lamp unit can be attached / detached smoothly.

  Furthermore, a projector according to the present invention includes the lamp unit, a spatial light modulation device that modulates light emitted from the lamp unit according to an image signal, a connection unit for connecting the open end of the nozzle, and a light emitting unit. And an air blowing unit that blows out or sucks air through a nozzle with respect to the sub-reflecting mirror. Since it has the ventilation means which blows or sucks air through the nozzle provided in the lamp unit, it is possible to obtain a projector that enables appropriate temperature control of the arc tube. Further, the projector may be used in an upright state or in an inverted state in which the upside-down state is reversed from the upright state. When a lamp unit including a sub-reflecting mirror is used, a change in the usage state of the lamp unit also occurs due to a change in the attitude of the projector. For example, when the projector is upright, the sub-reflecting mirror may cover the lower side of the light emitting unit. In this case, when the projector is used in an inverted state, the sub-reflecting mirror covers the upper side of the light emitting unit. If the sub-reflecting mirror covers the upper side of the light emitting section, the temperature of the arc tube tends to increase. Since the projector of the present invention has a blowing unit that blows or sucks air through the nozzle between the light emitting unit and the sub-reflecting mirror, even when the projector is used in an inverted state The arc tube can be sufficiently cooled by increasing the amount of air blown. That is, it is possible to obtain a projector that enables appropriate temperature control of the arc tube according to the usage state of the projector.

  As a preferred aspect of the present invention, it is desirable that the connecting direction of the open end to the connecting portion is substantially parallel to the attaching / detaching direction of the lamp unit. Since the connecting direction of the open end to the connecting portion is substantially parallel to the attaching / detaching direction of the lamp unit, the nozzle is not obstructed when attaching / detaching the lamp unit, and the lamp unit can be attached / detached smoothly.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a projector 1 according to a first embodiment of the invention. The projector 1 is a front projection type projector that projects light onto a screen (not shown) and observes an image by observing light reflected on the screen. The projector 1 generally includes a lamp unit 2, a device-side air passage 4, a blower fan (blower unit) 6, and an optical engine 8. In the description of the embodiment of the present application, the axis from the lamp unit 2 toward the optical engine 8 is defined as the Z axis. The axes orthogonal to the Z axis and perpendicular to each other are defined as an X axis and a Y axis. Further, the arrow direction of each axis is a positive direction, and the opposite direction is a negative direction. The lamp unit 2 includes an arc tube 11, a main reflecting mirror 12, and a sub reflecting mirror 13. The lamp unit 2 emits light including red (R) light, green (G) light, and blue (B) light. The lamp unit 2 is detachably attached to the attachment portion 1 a of the projector 1. The attaching / detaching direction is a direction indicated by an arrow P. A positive direction side (side with the irradiated surface) along the Z axis with respect to the light emitting unit 15 is referred to as a front side, and a negative direction side is referred to as a rear side. The positive direction side along the Y axis with respect to the light emitting unit 15 is referred to as the upper side, and the negative direction side is referred to as the lower side.

  FIG. 2 is an external perspective view showing a schematic configuration of the lamp unit 2 according to Embodiment 1 of the present invention. The arc tube 11 is, for example, an ultra high pressure mercury lamp. The inside of the arc tube 11 is sealed using, for example, a quartz member. The light emitting portion 15 is a spherical portion sandwiched between the first sealing portion 16 and the second sealing portion 17 in the arc tube 11 and emits light. Inside the light emitting unit 15, a discharge space in which a pair of electrodes is arranged is formed. The first sealing portion 16 is a cylindrical portion provided on the front side of the arc tube 11. The second sealing portion 17 is a cylindrical portion provided on the rear side of the arc tube 11.

  The main reflecting mirror 12 reflects the light emitted from the light emitting unit 15 and advances it to the front side. The main reflecting mirror 12 has substantially the same shape as a curved surface obtained by cutting a spheroidal surface obtained by rotating an ellipse about the central axis AX along a predetermined plane. The arc tube 11 is disposed on the central axis AX. In the present embodiment, the predetermined plane is a plane including the central axis AX. The predetermined plane may be a plane other than the plane including the central axis AX in order to increase the light use efficiency. The predetermined plane may be, for example, a plane parallel to the center axis AX or a plane having an angle with respect to the center axis AX.

  The arc tube 11 is disposed on the central axis AX. The main reflecting mirror 12 is configured by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal member on the surface of a base material formed into a desired shape. As the highly reflective member, a member having a high reflectance with respect to light having a wavelength in the visible region is used. By using the main reflecting mirror 12 having a shape obtained by cutting the spheroid, the lamp unit 2 can be made thinner than a lamp unit using a reflecting mirror whose spheroid is not cut. The main reflecting mirror 12 is not limited to the same shape as the curved surface obtained by cutting the spheroid. For example, the shape may be substantially the same as a curved surface obtained by cutting a rotating curved surface obtained by rotating a predetermined curve such as a parabola, or a free curved surface shape.

  The sub-reflecting mirror 13 reflects the light emitted from the light emitting unit 15 toward the light emitting unit 15. The sub-reflecting mirror 13 covers a part of the periphery of the light emitting unit 15 from below. A gap is provided between the sub-reflecting mirror 13 and the light emitting unit 15. The sub-reflecting mirror 13 is configured by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal member on the surface of a base material formed into a desired shape. As the highly reflective member, a member having a high reflectance with respect to light having a wavelength in the visible region is used. By providing the main reflecting mirror 12 and the sub-reflecting mirror 13, the light emitted from the light emitting unit 15 can be efficiently advanced to the optical engine 8.

  FIG. 3 is a cross-sectional view of the lamp unit 2 and the apparatus-side air passage 4. FIG. 3 shows the state of the lamp unit 2 and the device-side air passage 4 when the projector 1 is used in the upright state, and the state of the lamp unit 2 and the device-side air passage 4 when used in the inverted state. Both are shown. A nozzle 14 is connected to the sub-reflecting mirror 13 that covers the light emitting unit 15. The nozzle 14 has a cylindrical shape through which air can pass. The nozzle 14 is connected to the lower end of the sub-reflecting mirror 13 on the connection end 14a side which is one end thereof. The nozzle 14 is formed to extend downward from the connection end 14a side. The other end of the connection end 14a is an open end 14b. The nozzle 14 is formed so as to be substantially parallel to the attaching / detaching direction of the lamp unit 2 as a whole. The open end side 14 b of the nozzle 14 can be connected to the connection port 4 a of the device side air passage 4.

  An opening is formed in a portion of the sub-reflecting mirror 13 to which the nozzle 14 is connected. Thereby, the movement of the air through the nozzle 14 and the opening is enabled between the reflecting surface side of the sub-reflecting mirror 13 and the opposite surface side.

  The apparatus-side air passage 4 is disposed in the projector 1 so that air can pass through it. The device-side air passage 4 guides the air sent by the blower fan 6. The apparatus-side air passage 4 is disposed at a portion where the rotating curved surface that is the base of the main reflecting mirror 12 is cut with respect to the lamp unit 2 that is attached to the attachment portion 1a. In the apparatus-side air passage 4, a connection port 4 a for connecting to the open end 14 b of the nozzle 14 is formed. An elastic member 5 is disposed at the opening edge of the connection port 4a. When the open end 14b of the nozzle 14 is inserted and connected to the connection port 4a, the elastic member 5 closes the gap. The connecting direction of the nozzles 14 is substantially parallel to the attaching / detaching direction of the lamp unit 2.

  Since the attaching / detaching direction of the lamp unit 2 and the connecting direction of the nozzles 14 are substantially parallel, the nozzles 14 can be connected only by attaching the lamp unit 2. Furthermore, since the nozzles 14 are formed substantially parallel to the attaching / detaching direction of the lamp unit 2, the nozzles 14 are not easily obstructed when the lamp unit 2 is attached. As a result, problems such as the nozzle 14 being broken when the lamp unit 2 is mounted can be made difficult to occur. Moreover, the lamp unit 2 can be easily positioned by inserting the nozzle 14 into the connection port 4a. Further, since the device-side air passage 4 is disposed in a portion where the rotating curved surface that is the base of the main reflecting mirror 12 is cut and deleted, the vacant space is effectively used, and the projector 1 main body is downsized. Can contribute.

  The blower fan 6 is connected to the device-side air passage 4 and sends air into the device-side air passage 4. Here, the flow of air sent from the blower fan 6 will be described. The air sent from the blower 6 passes through the device-side air passage 4 and flows into the nozzle 14. The air that has flowed into the nozzle 14 is ejected from the opening of the sub-reflecting mirror 13 toward the gap between the sub-reflecting mirror 13 and the light emitting unit 15. The ejected air is blown to the light emitting unit 15 and passes through the gap between the sub-reflecting mirror 13 and the light emitting unit 15 to cause the air in the vicinity of the light emitting unit 15 to flow. Thereby, the arc tube 11 can be sufficiently cooled. In addition, since the nozzle 14 is provided below the sub-reflecting mirror 13, it is difficult to prevent the light emitted from the light emitting unit 15 from proceeding. As can be seen from FIG. 3, the light emitted downward from the light emitting unit 15 is reflected by the sub-reflecting mirror 13. Since the light reflected by the sub-reflecting mirror 13 is further reflected by the main reflecting mirror 12 and travels forward, it is difficult for the nozzle 14 to prevent the travel.

  Next, the optical engine 8 will be described. The concave lens 78 collimates the light emitted from the lamp unit 2. The first integrator lens 61 and the second integrator lens 62 have a plurality of lens elements arranged in an array. The first integrator lens 61 divides the light beam from the concave lens 78 into a plurality of parts. Each lens element of the first integrator lens 61 condenses the light beam from the concave lens 78 in the vicinity of the lens element of the second integrator lens 62. The lens element of the second integrator lens 62 forms an image of the lens element of the first integrator lens 61 on the spatial light modulator.

  The light that has passed through the two integrator lenses 61 and 62 is converted into linearly polarized light in a specific vibration direction by the polarization conversion element 63. The superimposing lens 64 superimposes the image of each lens element of the first integrator lens 61 on the spatial light modulator. The first integrator lens 61, the second integrator lens 62, and the superimposing lens 64 make the intensity distribution of light from the lamp unit 2 uniform on the spatial light modulator. The light from the superimposing lens 64 enters the first dichroic mirror 65. The first dichroic mirror 65 reflects R light and transmits G light and B light. The R light incident on the first dichroic mirror 65 has its optical path bent by the first dichroic mirror 65 and the reflection mirror 66, and enters the R light field lens 67R. The R light field lens 67R collimates the R light from the reflection mirror 66 and makes it incident on the R light spatial light modulator 68R.

  The spatial light modulator 68R for R light is a spatial light modulator that modulates R light according to an image signal, and is a transmissive liquid crystal display device. A liquid crystal panel (not shown) provided in the R light spatial light modulation device 68R encloses a liquid crystal layer for modulating light according to an image signal between two transparent substrates. The R light modulated by the R light spatial light modulator 68R is incident on a cross dichroic prism 69 which is a color synthesis optical system.

  The G light and B light that have passed through the first dichroic mirror 65 enter the second dichroic mirror 70. The second dichroic mirror 70 reflects G light and transmits B light. The G light incident on the second dichroic mirror 70 has its optical path bent by the second dichroic mirror 70 and is incident on the G light field lens 67G. The G light field lens 67G collimates the G light from the second dichroic mirror 70 and makes it incident on the G light spatial light modulator 68G. The G light spatial light modulator 68G is a spatial light modulator that modulates the G light according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 68G is incident on a different surface of the cross dichroic prism 69 from the surface on which the R light is incident.

  The B light transmitted through the second dichroic mirror 70 is transmitted through the relay lens 71, and then the optical path is bent by reflection at the reflection mirror 72. The B light from the reflection mirror 72 further passes through the relay lens 73, and then the optical path is bent by reflection by the reflection mirror 74, and enters the B light field lens 67B. Since the optical path of the B light is longer than the optical path of the R light and the optical path of the G light, relay lenses 71 and 73 are provided in the optical path of the B light in order to make the illumination magnification in the spatial light modulator equal to that of other color lights. The relay optical system to be used is adopted.

  The B light field lens 67B collimates the B light from the reflection mirror 74 and makes it incident on the B light spatial light modulator 68B. The B light spatial light modulator 68B is a spatial light modulator that modulates B light in accordance with an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulator 68B is incident on a surface of the cross dichroic prism 69 that is different from the surface on which the R light is incident and the surface on which the G light is incident.

  The cross dichroic prism 69 has two dichroic films 75 and 76 that are substantially orthogonal to each other. The first dichroic film 75 reflects R light and transmits G light and B light. The second dichroic film 76 reflects B light and transmits R light and G light. The cross dichroic prism 69 combines R light, G light, and B light incident from different directions and emits the light toward the projection lens 77. The projection lens 77 projects the light combined by the cross dichroic prism 69 toward the screen.

  By using the lamp unit 2 described above, the projector 1 can sufficiently cool the arc tube 11 and can reduce deterioration of the arc tube 11. Thereby, there is an effect that a highly reliable projector 1 can be obtained. Further, when the projector 1 is used in an inverted state, the sub-reflecting mirror 13 covers the upper side of the light emitting unit 15, and the temperature of the arc tube 11 tends to increase. When the projector 1 is used in an inverted state, the projector 1 has the air blowing means 6 that blows or sucks air through the nozzle 14 between the light emitting unit 15 and the sub-reflecting mirror 13. Even so, it is possible to sufficiently cool the arc tube 11 by increasing the air flow rate. That is, it is possible to obtain a projector that enables appropriate temperature control of the arc tube 11 according to the state of use.

  The projector 1 is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector 1 is not limited to a configuration including a spatial light modulator for each color light. The projector 1 may be configured to modulate two or three or more color lights with one spatial light modulator. The projector 1 is not limited to using a spatial light modulation device. The projector 1 may be a slide projector that uses a slide having image information. The projector 1 may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen. The lamp unit according to the present invention is not limited to that used for the projector 1. The lamp unit may be applied to, for example, a lighting device such as a flashlight or a headlight of an automobile.

  Moreover, you may comprise so that air may be suck | inhaled from the nozzle 14 by making the direction into which the ventilation fan 6 sends air into a reverse direction. Also in this case, the light in the vicinity of the light emitting unit 15 can be flowed to sufficiently cool the light emitting unit 15. Further, the amount of cooling of the arc tube 11 can be controlled by adjusting the amount of air sucked.

  FIG. 4 is a cross-sectional view of the lamp unit 2 and the apparatus-side air passage 4 according to the first modification of the first embodiment. The same parts as those in the above-described configuration are denoted by the same reference numerals, and redundant description is omitted.

  In the first modification, the attaching / detaching direction of the lamp unit 2 is the front-rear direction. The connection port 4a of the device side air passage 4 is also formed with the rear side facing. The nozzle 14 is bent halfway and is formed so that the open end 14b faces the front side. Thereby, the open end 14b side of the nozzle 14 becomes substantially parallel to the attaching / detaching direction of the lamp unit 2. Therefore, the present invention is applied also to a projector in which the mounting / demounting direction of the lamp unit 2 is the front / rear direction, the mounting / detaching of the lamp unit 2 is facilitated, and the air near the light emitting unit 15 is caused to flow. 15 can be sufficiently cooled.

  FIG. 5 is a cross-sectional view of the lamp unit 2 according to the second modification of the first embodiment. The same parts as those in the above-described configuration are denoted by the same reference numerals, and redundant description is omitted.

  In the second modification, the nozzle 14 is connected from the rear side of the sub-reflecting mirror 13. Of the reflecting surface of the sub-reflecting mirror 13, the portion where the nozzle 14 is connected and the opening is formed does not reflect light, so that the light utilization efficiency may be reduced. However, most of the light reflected by the portion corresponding to the portion where the opening is formed in the second modification is not incident on the reflecting surface of the main reflecting mirror 12 and diverges (see arrow Q). Therefore, if the nozzle 14 is connected from the rear side of the sub-reflecting mirror 13, it is possible to suppress a decrease in light use efficiency due to the formation of the opening. In other words, light can be efficiently extracted by connecting the nozzle 14 from the rear side of the sub-reflecting mirror 13.

  FIG. 6 is a cross-sectional view of the lamp unit 2 according to the third modification of the first embodiment. The same parts as those in the above-described configuration are denoted by the same reference numerals, and redundant description is omitted.

  In the third modification, the nozzle 14 is configured separately from the sub-reflecting mirror 13 and is connected to the opening of the sub-reflecting mirror 13. For the nozzle 14, a material different from that of the sub-reflecting mirror 13 may be used. For example, glass may be used. The nozzle 14 is connected from the rear side of the sub-reflecting mirror 13. Similar to the second modification, it is possible to suppress a decrease in light use efficiency due to the formation of the opening in the sub-reflecting mirror 13.

  The nozzle 14 is formed so as to extend in parallel with the arc tube 11 from the connection end 14a toward the rear side. The nozzle 14 extends in parallel with the arc tube 11 and is fixed to a portion of the sub-reflecting mirror 13 that covers the second sealing portion 17 of the arc tube 11. Examples of the fixing method include adhesion by an adhesive, welding, and screwing. By fixing the nozzle 14 to the sub-reflecting mirror 13, it is possible to make the nozzle 14 harder to be broken and stronger than when the nozzle 14 is connected to the sub-reflecting mirror 13 only by the connection end 14 a. Note that configuring the nozzle 14 separately from the sub-reflecting mirror 13 can be applied to other embodiments and modifications.

  FIG. 7 is a cross-sectional view of the lamp unit 2 according to the fourth modification of the first embodiment. The same parts as those in the above-described configuration are denoted by the same reference numerals, and redundant description is omitted.

  In the fourth modification, the nozzle 14 is connected from the front side of the sub-reflecting mirror 13. By bending the nozzle 14 extending from the sub-reflecting mirror 13 toward the front side downward, the lamp 2 according to the fourth modification can be applied to a projector in which the attaching / detaching direction of the lamp 12 is the vertical direction. it can.

  FIG. 8 shows a schematic cross-sectional configuration of the lamp unit 20 according to the second embodiment of the present invention. The lamp unit 20 according to the second embodiment has a sub-reflecting mirror 23 on the front side with respect to the light emitting unit 15. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The main reflecting mirror 22 has substantially the same shape as a spheroidal surface obtained by rotating an ellipse about the central axis AX. The main reflecting mirror 22 is configured by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal member on the surface of a base material formed into a desired shape. The main reflecting mirror 22 is not limited to a shape that is substantially the same as that of the spheroid, and may be a shape that is substantially the same as a rotating curved surface obtained by connecting a predetermined curve such as a parabola, a free curved surface shape, or the like.

  The sub-reflecting mirror 23 reflects the light emitted from the light emitting unit 15 toward the light emitting unit 15. The sub-reflecting mirror 23 covers a portion of the periphery of the light emitting unit 15 that is in front of the light emitting unit 15. A gap is provided between the sub-reflecting mirror 23 and the light emitting unit 15. The sub-reflecting mirror 23 is configured by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal member on the surface of a base material formed into a desired shape. By providing the main reflecting mirror 22 and the sub-reflecting mirror 23, the light emitted from the light emitting unit 15 can be efficiently advanced toward the front side.

  A nozzle 24 is connected to the sub-reflecting mirror 23 as in the first embodiment. The nozzle 24 is connected to the sub-reflecting mirror 23 from obliquely below. The nozzle 24 is bent halfway so that the open end 24b side extends downward. Thereby, the lamp unit 20 of the second embodiment can be applied to a projector in which the attaching / detaching direction of the lamp unit 20 is the vertical direction.

  As described above, even when the sub-reflecting mirror 23 is provided so as to cover the front side of the light emitting unit 15, the air in the vicinity of the light emitting unit 15 is made to flow by connecting the nozzles 24, so that the light emitting unit 15 is sufficient. Can be cooled. By forming the nozzle 24 to be thin, the nozzle 24 is less likely to block light from the lamp unit 20, and light can be extracted more efficiently. Further, by forming the nozzle 24 so that the open end 24b side extends toward the front side, it is possible to deal with the attachment and detachment of the lamp unit 20 in the front-rear direction with respect to the projector.

  As described above, the lamp unit according to the present invention is suitable for use in a projector.

1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment of the invention. The external appearance perspective view which shows schematic structure of a lamp unit. The cross-sectional view of a lamp unit and an apparatus side air path. FIG. 6 is a cross-sectional view of a lamp unit and an apparatus-side air passage according to a first modification of the first embodiment. FIG. 6 is a cross-sectional view of a lamp unit according to Modification 2 of the first embodiment. FIG. 6 is a cross-sectional view of a lamp unit according to Modification 3 of the first embodiment. FIG. 6 is a cross-sectional view of a lamp unit according to Modification 4 of the first embodiment. The figure which shows schematic sectional structure of the lamp unit which concerns on Example 2 of this invention.

DESCRIPTION OF SYMBOLS 1 Projector, 2 lamp unit, 4 apparatus side air path, 4a connection port, 5 elastic member, 6 ventilation fan (blower means), 8 optical engine, 11 light emission tube, 12 main reflector, 13 sub reflector, 14 nozzle, 14a connection end, 14b open end, 15 light emitting section, 20 lamp unit, 22 main reflector, 23 sub-reflector, 24 nozzle, 24b open end

Claims (8)

An arc tube comprising a light emitting part for emitting light;
A sub-reflector that covers a part of the periphery of the light emitting unit and reflects light emitted from the light emitting unit;
A main reflecting mirror that reflects the light emitted from the light emitting unit and the light reflected by the sub-reflecting mirror;
A lamp unit, comprising: a nozzle connected to the sub-reflecting mirror to allow air to pass therethrough and flow air between the sub-reflecting mirror and the light emitting unit. An opening is formed in the sub-reflecting mirror,
The lamp unit according to claim 1, wherein a connection end of the nozzle is connected to the opening. The main reflecting mirror has substantially the same shape as a curved surface obtained by cutting a rotating curved surface obtained by rotating a predetermined curve around a central axis at a predetermined surface,
The lamp unit according to claim 1, wherein the sub-reflecting mirror covers a side opposite to the side where the main reflecting mirror is provided with respect to the light emitting unit.   The lamp unit according to claim 3, wherein the nozzle is connected to the sub-reflecting mirror from the side opposite to the irradiated surface side. The main reflecting mirror has substantially the same shape as a rotating curved surface obtained by rotating a predetermined curve around a central axis,
The lamp unit according to claim 1, wherein the sub-reflecting mirror covers an irradiated surface side with respect to the light emitting unit. The lamp unit is detachable from the projector,
The open end side, which is the side opposite to the connection end to the sub-reflecting mirror, of the nozzles is substantially parallel to the attaching / detaching direction of the lamp unit with respect to the projector. The lamp unit according to claim 1. The lamp unit according to any one of claims 1 to 6,
A spatial light modulator that modulates light emitted from the lamp unit according to an image signal;
A connecting portion for connecting the open end of the nozzle;
A projector comprising: air blowing means for blowing or sucking air through the nozzle between the light emitting unit and the sub-reflecting mirror.   The projector according to claim 7, wherein the connecting direction of the open end to the connecting portion is substantially parallel to the attaching / detaching direction of the lamp unit.

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