JP2006189486A - Rear-projection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate noise due to the rotation of a cooling fan, by dispensing with the cooling fan. <P>SOLUTION: The rear projection apparatus 1 is constituted so that an air intake port 7 is formed in the lower part of the rear plate 2a of a lower housing 2, and an optical unit 31, a control unit 33 and a power supply unit 34 are stacked in this order starting from below. A duct 4 is positioned at one end at the rear of the rear projection device 1 so as to extend vertically. A light source 10 is disposed in the duct 4. The lower part of the duct 4 has a lower opening 5a, communicating with the inside of the lower housing 2. An upper opening 6a is formed in the upper end of the duct 4. When the use of the apparatus is started, the units 31, 33, 34 and the light source 10 are heated. Air, entering the lower housing 2 through the air intake port 7, flows upward and enters inside the duct 4; and the air, entering inside of the duct 4, flows upward and is discharged. Such a current of air cools the units 31, 33, 34 and the light source 10, thus dispensing with a cooling fan. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention arranges a light source that becomes high temperature by lighting in the duct and cools the light source by an air flow generated in the duct, thereby preventing the light source from becoming excessively high temperature even without a cooling fan. The present invention relates to a rear projection device that realizes quietness.

  Conventionally, there is a projector (projection-type image display device) that displays an image on a screen, which is divided into a front projection type device and a rear projection type device depending on the projection direction onto the screen. A rear projection apparatus (rear projection apparatus) is widely used as a rear projection television apparatus having a configuration in which a screen is attached to a casing.

  The rear projection apparatus is generally divided into a lower casing and an upper casing. A light source, an optical unit, a control unit, a power feeding unit, and the like are arranged inside the lower casing, and a reflection mirror and a screen are arranged in the upper casing. It is attached. In many cases, the upper housing has a sealed structure so that dust or the like is not projected onto the screen.

  An optical unit housed in the lower housing includes a light valve that forms modulated light according to an image based on light emitted from a light source, a projection lens that projects the formed modulated light to a reflecting mirror in the upper housing, and the like. . The control unit is a unit including a circuit that converts an image signal to be projected input from the outside into a signal that is optimal for the light valve of the optical unit, a tuner unit that performs reception processing of broadcast radio waves, and the like. Further, since the light source needs to be positioned with respect to the optical unit, the light source is housed in a lamp cabinet and fixed at a required position in the lower housing. The light source itself is configured to cover a lamp (discharge type arc tube) such as a metal halide lamp and a high-pressure mercury lamp with a reflector.

  The light source, optical unit (especially light valve), control unit, power supply unit, etc. in the lower housing generate heat when the image is displayed on the screen. In particular, the luminous tube of the light source reaches a very high temperature and the reflector itself is Since it becomes high temperature by irradiation, a cooling fan and a duct for guiding cooling air are usually provided in the lower housing (see Patent Documents 1 and 2). In addition, an apparatus is also disclosed in which a cooling container that covers a light source and a light valve is provided in order to improve cooling performance, and a cooling medium is circulated in the cooling container (see Patent Document 3).

In addition, the arc tube of the light source has a structure in which harmful mercury, halogen gas, etc. are sealed inside a cylindrical glass body sealed at both ends, and since the internal pressure exceeds 150 atm when lighting, When the glass body ruptures for some reason, a loud burst sound is generated and harmful substances and glass are scattered. For this reason, there is a light source with a substantially hermetic explosion-proof specification in which the opening side of the reflector is closed with a glass plate or an optical lens, and many of the light sources used in the rear projection apparatus have an explosion-proof specification. Note that an explosion-proof light source is inferior in heat dissipation compared to an open type light source, so that the power input to the light source is limited to about 150 W (watts) or less.
JP 11-41547 A JP 2004-45990 A JP-A-11-282361

  Since the conventional rear projection apparatus is provided with a cooling fan and a duct, the blowing sound in the duct due to the forced cooling of the fan, the vibration sound accompanying the rotation of the fan, and the rotating sound of the fan itself, etc. even during image display There is a problem that various kinds of noises are generated and the user's viewing is disturbed by these noises. In particular, an explosion-proof light source often used in a rear projection apparatus has a lower cooling performance than an open light source, and thus has a large dependency on forced cooling by a fan, so that the above-described problem becomes significant.

  Further, in the apparatus according to Patent Document 3, since cooling is performed by circulating a cooling medium, there is no problem of noise caused by a cooling fan. However, since the arc tube of the light source has a short lifetime, it is necessary to replace the light source after a certain period of time. Therefore, since there is a complicated configuration related to the circulation of the cooling medium, there are various types including replacement of the light source. Another problem arises that it becomes difficult to maintain. Furthermore, since a pump, a heat exchanger, and the like are newly required for circulating the cooling medium, the cost of the apparatus increases. Therefore, it is difficult to adopt the configuration in which the cooling medium is circulated in an actual product. .

The present invention has been made in view of such a problem, and provides a rear projection device that realizes noise reduction during viewing by ensuring the required cooling performance of the light source even if the cooling fan is eliminated. The purpose is to do.
It is another object of the present invention to provide a rear projection apparatus that can ensure required cooling performance for various units housed in a housing even if the cooling fan is eliminated.

  In order to solve the above problems, a rear projection apparatus according to the present invention includes a light source in which an arc tube is arranged in a concave reflector, an optical unit that forms modulated light according to an image based on light emitted from the light source, In a rear projection apparatus comprising a screen on which modulated light emitted from the optical unit is projected and a duct for guiding an air flow, the light source is disposed inside the duct, and the light source is disposed on a peripheral wall of the duct. A light-transmitting portion that allows light emitted from the light to pass therethrough is formed.

  In the present invention, since the light source having a high temperature is disposed in the duct, the gas in the duct around the light source is warmed by the heat generated by the light source itself, and this warmed gas is mixed with the gas outside the duct. Instead, it becomes a mass and moves along the duct, so that a gas flow occurs in the duct. As a result, the light source can be cooled by the gas flowing in the duct, the cooling fan existing in the conventional rear projection apparatus can be eliminated, and the noise accompanying the rotation of the fan can be eliminated. In addition, since a light-transmitting part is formed on the peripheral wall of the duct, light emitted from the light source is transmitted from the light-transmitting part to the light source unit located outside the duct, so that the image display on the screen is the same as in the past. Can be done. In addition, as a light transmission part, forming a hole in a duct surrounding wall, or making the surrounding wall location to transmit light transparent is applicable.

In the rear projection device according to the present invention, the duct includes a support portion that supports the light source disposed therein.
In the present invention, the duct is provided with a support portion that supports the light source disposed therein, so that the lamp cabinet used for positioning and fixing the light source can be eliminated, and the duct can be used instead of the lamp cabinet. The internal configuration of the apparatus can be simplified. In order to facilitate replacement of the light source, it is preferable that the duct can be divided in the vicinity of the portion where the light source support portion is provided.

The rear projection apparatus according to the present invention is characterized in that the duct extends from the lower part of the apparatus to the upper part of the apparatus.
In the present invention, since the duct extends from the lower part of the apparatus to the upper part of the apparatus, the mass difference between the gas inside and outside the duct is filled with a light mass of light gas having a specific gravity heated by the heat generated by the light source. As a result, buoyancy is generated inside the duct as a chimney effect. If this buoyancy exceeds the ventilation resistance in the duct, even if there is no cooling fan, it is possible to form a gas flow that a light gas mass naturally rises in the duct, and the light source can be cooled more efficiently. . In consideration of cooling efficiency, it is optimal to form the duct in a straight line in the vertical direction in order to reduce the draft resistance. It can also be shaped.

The rear projection apparatus according to the present invention is characterized in that the upper end of the duct is opened so that the inside of the duct communicates with the outside of the apparatus.
In the present invention, since the upper end of the duct opens and communicates to the outside of the apparatus, the warmed gas in the duct can be smoothly discharged to the outside, and the flow of the light source can be prevented so as not to disturb the flow in the duct. Cooling efficiency can be increased.

In the rear projection apparatus according to the present invention, the lower end of the duct is opened so that the inside of the duct communicates with the inside of the apparatus.
In the present invention, since the lower end of the duct opens and communicates with the inside of the apparatus, it is possible to generate an air flow that sucks and raises the gas inside the apparatus into the duct. That is, the warmed gas rises as the light source disposed in the duct generates heat, and a negative pressure is generated near the lower portion of the duct. Therefore, by opening the lower end of the duct, the gas inside the device existing near the lower end of the duct is sucked into the duct and can be continuously sent into the duct, and the light source generated in the duct A cooling airflow can be maintained.

The rear projection apparatus according to the present invention is characterized in that a cross-sectional shape in a direction perpendicular to the extending direction of the duct is a quadrilateral or more polygon or a substantially circular shape.
In the present invention, since the cross-sectional shape of the duct is a quadrilateral or more polygon or substantially circular, the flow of gas in the duct can be improved. Usually, since gas is a viscous fluid, when gas flows in a duct, viscous resistance will arise in a contact location with the duct inner wall. In addition, if there is a corner portion in the duct, the viscous resistance particularly at the corner portion increases, and the gas does not flow easily. Therefore, in the present invention, when the cross-sectional shape of the duct is a quadrilateral or more polygonal, the sandwiching angle of the corner portion can be within an angular range where the viscous resistance does not increase, and when the cross-sectional shape of the duct is substantially circular The corner part itself disappears and the viscous resistance is suppressed to ensure a smooth air flow. In addition, when the cross-sectional shape of a duct is a polygon, it does not necessarily need to be a regular polygon, and can be made into the polygon according to the structure inside an apparatus.

The rear projection device according to the present invention is characterized in that the light source includes a heat conducting member that connects the reflector and the arc tube across the space in the reflector.
In the present invention, since the arc tube and the reflector are connected by the heat conducting member, the heat generated in the arc tube by lighting can be conducted to the reflector through the heat conducting member. Furthermore, since the heat conducted to the reflector is transferred to the gas flowing in the duct, the temperature of the arc tube and the reflector can be suppressed to an appropriate temperature range without a cooling fan, and stable use of the rear projection apparatus can be ensured.

  The heat conducting member is preferably made of a metal such as copper or aluminum having a good thermal conductivity, ceramics made of aluminum nitride, or the like, and the heat conducting member itself is heated by irradiation of light from the reflector. In order to prevent this, it is preferable to maintain the reflectivity of the surface of the heat conductive member by covering the surface of the heat conductive member with an antioxidant film. Furthermore, the reflector in the case where the heat conducting member is provided needs to apply a metal material as a material from the viewpoint of heat conductivity, and aluminum, copper or the like having a heat conductivity of 10 W / m · K or more is preferable. .

In the rear projection apparatus according to the present invention, the light source includes a coating film that covers the reflection surface on the inner peripheral side of the reflector.
In the present invention, since the reflecting surface of the reflector is covered with the coating film, it is possible to reduce the thermal effect caused by reflecting the light emitted from the arc tube. In addition, it is preferable that the coating film has a characteristic of selectively converting light in the infrared wavelength region into heat and dissipating heat to the reflector, and such characteristics improve the heat dissipation of the reflecting surface, Heat generated from the reflector can be easily transferred to the gas in the duct, and the temperature of the reflector can be maintained within an appropriate temperature range without a cooling fan. Moreover, since heat dissipation becomes favorable, the temperature of a reflective surface does not rise excessively, and deterioration of a reflective surface can also be prevented.

In the rear projection device according to the present invention, the light source includes a heat radiating fin on an outer peripheral surface of the reflector.
In the present invention, since the heat dissipating fins are provided on the outer peripheral surface of the reflector, the contact area between the gas existing around the outer peripheral surface of the reflector and the reflector increases, and the heat of the reflector is efficiently transferred to the surrounding gas. It becomes possible to move, further improving the heat dissipation of the reflector and improving the cooling performance of the light source.

The rear projection device according to the present invention is characterized in that the light source includes a translucent member that closes the reflection-side opening of the reflector.
In this invention, since the translucent member which closes the opening of a reflector is provided, a light source can be made into an explosion-proof specification and the leakage of a plosive sound and a harmful substance can be prevented. Since the light source also dissipates heat from the translucent member that closes the opening of the reflector, the position of the light source in the duct is adjusted so that the entire light source is contained in the duct so that gas flows around the translucent member. It is preferable to consider.

The rear projection apparatus according to the present invention includes a housing that houses the optical unit, and an air inlet is formed at a position below the light source of the housing.
In the present invention, since the intake port is formed at a position below the light source of the housing, natural convection occurs in which the gas around the light source rises due to heat dissipation of the light source. When the air inlet is formed, cold gas outside the apparatus can easily flow into the apparatus from the air inlet. As a result, an air flow from the outside of the apparatus to the inside of the apparatus through the air inlet can be formed, and the optical unit and other various units in the housing can be cooled by the air flow.

In the rear projection apparatus according to the present invention, the housing stores a power supply unit that supplies power to the light source and the optical unit, and the power supply unit is disposed between the light source and the air inlet in the height direction. It is characterized by being.
In the present invention, since the power supply unit is disposed between the light source and the air intake port, the air intake port with respect to the power supply unit serving as a heat source and the light source that generates a large amount of heat compared to the power supply unit are As a result, gas can easily flow from the inside to the inside of the apparatus, and the gas that has flowed in can easily rise, and an airflow suitable for cooling the power supply unit can be formed.

  In other words, the gas around the power supply unit is also warmed by the heat generated by the power supply unit, and an upward airflow is generated. This upward airflow is connected to the airflow formed by the light source, so that the gas flow by natural convection is further strengthened and cooled. Efficiency can be improved. In particular, when the duct extends from the lower part of the device to the upper part of the device and the lower end of the duct is open to communicate with the inside of the device, the natural convection due to heat generated by the power supply unit can be smoothly connected to the gas flow in the duct. The cooling performance of the power supply unit and the light source can be improved by the flow from the air inlet to the duct. It should be noted that the power supply unit is arranged between the light source and the air inlet so that the power supply unit overlaps with a range not less than the height of the peripheral edge that is the lowest part of the air inlet and not more than the height of the upper part of the light source. Means the same (hereinafter the same).

In the rear projection apparatus according to the present invention, the housing houses a control unit that performs control processing related to formation of modulated light of the optical unit, and the control unit includes the light source and the air inlet in the height direction. It is arrange | positioned between.
In the present invention, since the control unit for performing the control process related to the formation of the modulated light of the optical unit is disposed between the light source and the air inlet, the required cooling performance can be ensured without the cooling fin, and the projected image can be obtained. Noise caused by cooling fans that hinder viewing can be eliminated. Since the control unit is a heat source, although the calorific value is inferior to that of the light source, the gas around the control unit is warmed and an upward air flow is generated, so the air flow rising through the control unit from the intake port formed in the housing The inside of the device can be cooled.

In the rear projection apparatus according to the present invention, the optical unit includes a reflecting member that is disposed between the light source and the air inlet in a height direction and guides light emitted from the light source to the optical unit. It is characterized by.
In the present invention, the calorific value is inferior to that of the light source, but since the optical unit serving as the heat source is disposed between the light source and the air inlet, the gas around the optical unit is warmed and an upward air flow is generated. Therefore, the inside of the apparatus can be efficiently cooled by the airflow rising through the optical unit from the air inlet formed in the housing.

  In the rear projection apparatus according to the present invention, the housing includes a power supply unit that supplies power to the light source and the optical unit, and a control unit that performs control processing related to formation of modulated light of the optical unit, The unit is arranged between the light source and the air inlet in the height direction, and the control unit is arranged between the power supply unit and the air inlet in the height direction, and the optical unit Is disposed between the control unit and the air inlet in the height direction, and includes a reflecting member that guides light emitted from the light source to the optical unit.

  In the present invention, an optical unit, a control unit, a power supply unit, and a light source are arranged in order from the lower part of the apparatus to the upper part of the apparatus in the height direction. As a result, the arrangement is most suitable for the generation of natural convection, and the upward airflow generated by each unit can be connected to form a strong upward airflow without a cooling fan, improving the cooling performance inside the device. .

  In addition, if the duct extends from the lower part of the device to the upper part of the device, the upper end of the duct opens to the outside of the device and the lower end of the duct opens at a height equal to or higher than the power supply unit inside the device, A series of airflows that rise to the optical unit, control unit, and power supply unit can be guided into the duct, and merged with the upward airflow generated by the light source in the duct and smoothly exhausted outward from the opening at the upper end. A large flow is formed, and the cooling performance of each unit and the light source can be further improved.

In the present invention, since the light source having a high temperature is arranged inside the duct, the gas in the duct is warmed by the heat generated by the light source itself, and an air flow is generated. Various types of noise caused by the rotation of the fan can be eliminated by eliminating the need for a fan.
In the present invention, the duct is provided with a support portion that supports the light source disposed therein, so that the lamp cabinet used for positioning and fixing the light source can be eliminated, and the duct itself can be used as the lamp cabinet. The device configuration can be simplified.

In the present invention, since the duct extends from the lower part of the apparatus to the upper part of the apparatus, it is possible to form an air flow in which a mass of light gas having a specific gravity heated by the heat generated by the light source rises, thereby improving the cooling performance of the light source. It can be further improved.
In the present invention, since the upper end of the duct is opened to the outside of the apparatus, the warmed gas in the duct can be smoothly discharged to the outside.
In the present invention, since the lower end of the duct opens and communicates with the inside of the apparatus, the gas inside the apparatus can be sent into the duct to form a continuous flow airflow.
In the present invention, since the cross-sectional shape of the duct is a quadrilateral or more polygonal or substantially circular shape, it is possible to suppress the resistance in the duct and form a smooth air flow.

In the present invention, since the arc tube and the reflector are connected by the heat conducting member, the heat generated in the arc tube by lighting can be conducted to the reflector through the heat conducting member, and the cooling performance of the arc tube is improved. it can.
In the present invention, since the reflecting surface of the reflector is covered with the coating film, the heat dissipation of the reflecting surface can be improved, and the cooling property of the light source can be improved.

In the present invention, since the heat dissipating fins are provided on the outer peripheral surface of the reflector, the contact area between the surrounding gas and the reflector can be increased, and the heat of the reflector is efficiently transferred to the surrounding gas to cool the light source. Increases sex.
In this invention, since the translucent member which closes the opening of a reflector is provided, a light source can be made into an explosion-proof specification and the leakage of a plosive sound and a harmful substance can be prevented.

In the present invention, since the air inlet is formed at a position below the light source, the air flow is accompanied by heat flow from the light source, so that the gas can be sucked into the apparatus from the air inlet and the cooling inside the apparatus can be improved.
In the present invention, since the power supply unit is disposed between the light source and the air inlet, the gas flows easily from the air inlet to the inside of the apparatus due to the positional relationship between the air inlet and the light source with respect to the power supply unit. Can be raised to form a smooth gas flow inside the apparatus.

In the present invention, since the control unit serving as a heat source is disposed between the light source and the intake port, the gas flow suitable for cooling can be formed by promoting the intake of the gas from the intake port.
In the present invention, since the optical unit serving as a heat source is disposed between the light source and the intake port, the suction of gas from the intake port can be promoted and a gas flow suitable for cooling can be formed.
In the present invention, an optical unit, a control unit, a power supply unit, and a light source are arranged in order from the lower part of the apparatus to the upper part of the apparatus in the height direction. As a result, an air flow suitable for cooling can be formed with an arrangement configuration most suitable for the generation of natural convection.

  1-3 have shown the external appearance of the rear projection apparatus 1 which concerns on embodiment of this invention. The rear projection apparatus 1 according to the present embodiment has a configuration in which a lower casing 2 at the lower part of the apparatus and an upper casing 3 at the upper part of the apparatus are combined. In addition, a duct 4 is provided at one of the chamfered portions (left side in FIG. 1). The rear projection apparatus 1 is characterized in that a light source 10 is disposed inside a duct 4 (see FIGS. 2 and 3), and the light source 10 is cooled by an air flow generated in the duct 4 without providing a cooling fan. It is said.

  The lower housing 2 of the rear projection device 1 has a horizontally long rectangular air inlet 7 at the bottom of the back plate 2a (see FIG. 1), and the outside of the device communicates with the inside of the device through the air inlet 7. Thus, the gas around the outside of the lower housing 2 can be taken into the apparatus. The intake port 7 is provided with a louver 7a for internal protection.

  2-6, the lower housing | casing 2 is accommodated in the inside in the state which accumulated the optical unit 31, the control unit 33, and the electric power feeding unit 34. As shown in FIG. The optical unit 31 is disposed at a position that is the lowest position in the height direction and that is above the lower edge that is the lowermost portion of the air inlet 7. A control unit 33 including a circuit for performing a control process for converting an image signal to be projected input from the outside into a signal optimal for the light valve of the optical unit 31 is disposed above the optical unit 31. Furthermore, a power supply unit 34 that supplies power to the light source 10, the optical unit 31, the control unit 33, and the like is disposed above the control unit 33. Each unit 31, 33, 34 is fixed by a mounting portion (not shown) provided in the lower housing 2, and positioning inside the lower housing 2 is performed. The control unit 33 of the present embodiment also includes a tuner unit that performs broadcast radio wave reception processing.

  Each unit 31, 33, 34 generates heat as the rear projection apparatus 1 is used, but the amount of heat generation is the largest in the power supply unit 34, the second is the control unit 33, and the third is the optical unit 31. Due to the difference in the amount of heat generated, the units 31, 33, and 34 are arranged in the height direction from the lower part of the apparatus to the upper part of the apparatus, from the smallest to the largest.

  The optical unit 31 is covered with a cabinet 32. As shown in FIGS. 5 and 6, the cabinet 32 is formed of a box-shaped main body cabinet portion 32c. The main body cabinet portion 32c includes a duct-shaped light guide cabinet portion 32a extending in the vertical direction so that the upper end portion faces the light source 10, and a duct extending in the vertical direction with the projection lens 46 attached to the upper end. The projection cabinet 32b (see FIG. 5) is connected to each other.

  As shown in FIG. 11 (a), the light guide cabinet portion 32a reflects the light K emitted from the light source 10 therein and guides it into the main body cabinet portion 32c of the optical unit 31 (reflecting members). Is equivalent). Since the light guide cabinet portion 32a is not required to be sealed, many slits (not shown) are formed in the peripheral wall portion to ensure good air permeability, and a lower opening 5a of the duct 4 described later. So as not to obstruct the flow of air to.

  Further, as shown in FIG. 11B, the main body cabinet portion 32c includes a reflecting mirror 38, a color wheel 39, a rod lens 40, a condenser lens 41, a TIR prism 42, a reflecting mirror 43, and a DMD (Digital Micromirror Device :). 44 (registered trademark, the same applies hereinafter) 44 is arranged in accordance with the traveling direction of the light K guided from the light guide cabinet section 32a, and a circuit board (not shown) for controlling each section of such an optical system is also provided inside. It is stored. The DMD 44 corresponds to a light valve, and is formed by an element that generates an image by controlling a mirror array that can move in the micron order, and generates modulated light of an image based on the light K from the light source 10. It generates heat as it is generated. In addition, it is also possible to use a liquid crystal panel for the light valve instead of the DMD.

  Further, as shown in FIG. 11C, the projection cabinet section 32b has a reflecting mirror 45 attached therein, which guides the modulated light generated by the DMD 44 to the projection lens 46 and projects the modulated light from the projection lens 46. Like to do. The inside of the main body cabinet portion 32c and the projection cabinet portion 32b has a sealed structure because dust resistance is required.

  On the other hand, as shown in FIGS. 4 and 5, the upper housing 3 has a reflection mirror 8 attached to the inside along the back wall portion 3a and a screen 9 attached around the front frame portion 3e. The upper housing 3 has an opening 3d formed in a part of the lower plate portion 3c. When the upper housing 3 is combined with the upper portion of the lower housing 2, the projection lens 46 is accommodated in the opening 3d. I am doing so. Further, when the upper housing 3 is combined with the lower housing 2, the opening 3 d is closed by the upper plate portion 2 c of the lower housing 2, and the hermeticity inside the upper housing 3 is ensured. .

  As shown in FIG. 4, the regions where the modulated light projected from the projection lens 46 is reflected by the reflection mirror 8 and travels toward the screen 9 are the left and right reflected lights H1 and H2 traveling on the outermost side, and the reflection mirror 8. When the obstacle exists in this range, the image displayed on the screen 4 is missing. Therefore, the light guide cabinet 32a and the duct 4 are arranged so as not to enter the range. It has been decided.

  In addition, the duct 4 which is a feature of the rear projection apparatus 1 of the present embodiment extends in the vertical direction from the apparatus lower part to the apparatus upper part, and the cross-sectional shape orthogonal to the extending direction is substantially circular. The duct 4 has a structure in which a lower duct portion 5 and an upper duct portion 6 are combined. The lower duct portion 5 is formed integrally with the lower housing 2 as shown in FIGS. A part of the peripheral wall of the lower duct portion 5 enters the inside of the lower housing 2 from the oblique plate portion 2 b of the body 2.

  The lower duct portion 5 is formed by removing the lower peripheral wall portion corresponding to the inner side of the lower housing 2 to form the lower opening 5a, and the upper peripheral wall portion corresponding to the inner side of the lower housing 2. A semicircular pilot hole 5b is formed in 5c. The diameter of the pilot hole 5b is ensured so that light emitted from the light source 10 disposed inside the duct 4 is not blocked. The position of the upper edge 5e of the lower opening 5a in the height direction is higher than the upper surface 34a of the power supply unit 34 housed in the lower housing 2 as shown in FIG. The positional relationship is such that a part of the power supply unit 34 overlaps the opening range of the opening 5a.

  Further, as shown in FIG. 7, the lower duct portion 5 is provided with a pair of support portions 19 so as to protrude toward the inside of the duct from both sides of the upper peripheral edge of the lower hole 5b. The set of support portions 19 sandwiches the flange portion 11b of the reflector 11 of the light source 10 shown in FIG. 10, and has an arc shape that matches the outer peripheral shape of the flange portion 11b at the tip of the inwardly projecting plate portion 19a. The arc portion 19b is provided, and a groove portion 19c into which the rib 11b is fitted is formed in the arc portion 19b.

  By providing such a support portion 19 in the vicinity of the upper portion of the lower duct portion 5, the access to the light source 10 is improved by removing the upper duct portion 6, and the light source 10 can be easily replaced. Furthermore, since the light source 10 is positioned by the support portion 19, the light source 10 completely enters the inside of the duct 4, and not only around the reflector 11 of the light source 10 but also on the front surface on the light emitting side. A space for flowing the gas can be secured, and the heat emitted from the light source 10 by flowing the gas around the entire light source 10 can be efficiently transferred to the surrounding air.

  The upper duct portion 6 combined with the lower duct portion 5 is formed in a cylindrical shape, and a semicircular upper hole 6b is formed in the peripheral wall portion 6d on the inner side of the lower housing 2 on the lower end side. Yes. Note that the upper hole 6b has a shape that is the upper and lower sides of the lower hole 5b of the lower duct portion 5, and the upper hole 6b and the lower hole 5b are combined to form a circular light transmitting portion. In addition, a depression (not shown) for avoiding interference with the upper duct portion 6 is formed in the oblique plate portion 3b (see FIG. 2) of the upper housing 3 corresponding to the location where the upper duct portion 6 is attached. ing.

  Further, the upper duct portion 6 is provided with an upper opening 6a at the upper end so that the outside of the apparatus communicates with the inside of the upper duct portion 6 through the upper opening 6a. In addition, a louver 6c is provided in the upper opening 6a so that hands cannot be put into the duct. The opening area of the upper opening 6a is at least 1.2 times the opening area of the air inlet 7 of the lower housing 2 so that the air expanding inside the apparatus and the duct 4 can be discharged smoothly. ing.

  FIG. 8 shows a state in which the light source 10 disposed inside the duct 4 is disassembled. The light source 10 is explosion-proof specification, and has a disk-shaped explosion-proof glass 29 (corresponding to a translucent member) that closes the opening 11d of the concave reflector 11 in which the arc tube 12 is disposed. An optical lens can be applied in place of the explosion-proof glass 29. The light source 10 has an impeller-like heat conducting member 20 that connects the arc tube 12 and the reflector 11, and conducts heat generated in the arc tube 12 by lighting to the reflector 11 by the heat conducting member 20. Hereinafter, the configuration of each part of the light source 10 will be described.

  As shown in FIG. 9, the reflector 11 is provided with a flange portion 11b on the outer peripheral edge on the opening 11d side of the concave mirror portion 11a in which the inner peripheral surface 11f is formed in an elliptical surface or a hyperboloid. A cylindrical portion 11c for attaching the arc tube 12 is provided at the opposite end. The concave mirror part 11a, the flange part 11b, and the cylindrical part 11c correspond to the base material of the reflector 11, and a metal material having a thermal conductivity of 10 W / m · K or more is applied to the base material. Aluminum having a conductivity of about 200 W / m · K is used.

  The concave inner peripheral surface 11f of the concave mirror part 11a is a reflecting surface, and the inner peripheral surface 11f is covered with a coating film 17 to improve thermal diffusibility. The coating film 17 has a three-layer structure as shown in FIG. 10, and includes an infrared heat conversion layer 17a, a gloss buffer layer 17b, and a visible light reflection layer 17c from the inner peripheral surface 11f side.

  The infrared heat conversion layer 17a is formed by anodizing the inner peripheral surface 11f, and absorbs light in a wavelength region that passes through the gloss buffer layer 17b and the visible light reflection layer 17c to efficiently convert heat. The gloss buffer layer 17b is formed on the infrared heat conversion layer 17a by baking a Si-based resin or a polyimide-based resin at a high temperature so that the infrared conversion layer 17a and the visible light reflecting layer 17c are not in direct contact with each other. It is intended to buffer both. The visible light reflection layer 17c is formed on the gloss buffer layer 17b and reflects visible light. Therefore, the reflector 11 of the present embodiment has the above-described coating film 17 having the laminated structure, so that even if the light emitted from the arc tube 12 is reflected, heat can be efficiently diffused and the reflecting surface is deteriorated. While preventing, the heat dissipation from the reflector 11 is also improved.

  As shown in FIGS. 8 and 9, the reflector 11 is formed with a hole 11h for mounting the arc tube 12 so that the central top 11i of the inner peripheral surface 11f communicates with the inside of the cylindrical portion 11c. A fitting surface 11g for fitting the heat conducting member 20 is recessed in the inner peripheral edge of the peripheral surface 11f on the flange portion 11b side. A recess 11e for attaching the explosion-proof glass 29 is formed on the end surface of the flange portion 11b, and a hole 11j for drawing out the lead wire d2 of the arc tube 12 is provided in the concave mirror portion 11a. .

  The arc tube 12 attached to the hole 11h of the reflector 11 is an ultra-high pressure mercury lamp, and is mainly composed of a glass body 13 made of quartz glass having sealing portions 13d on both ends and a pair of tungsten electrodes 14 and 15. Has been. The tungsten electrodes 14 and 15 are arranged to face each other in a chamber portion 13 c that swells in a spherical shape at the center of the glass body 13, and a predetermined amount of mercury and a rare gas are sealed in the chamber portion 13.

  The tungsten electrodes 14 and 15 in the chamber portion 13 are connected so as to be electrically connected to the molybdenum foil sealed at the end portions 13a and 13b of the glass body 13, and lead wires d1 and d2 are connected from the molybdenum foils. Is extended. The lead wires d1 and d2 are connected to the power supply unit 34 so that power can be supplied to the tungsten electrodes 14 and 15.

  In addition, each tungsten electrode 14, 15 has an inclined surface so that the middle of the tip is pointed at the apex, and the angle range between the inclined surfaces of each tungsten electrode 14, 15 regulates the luminance distribution of light generated by discharge. To do. That is, light traveling within an angle range formed between opposing slopes is not buffered by the slope, and such light travel range provides high brightness, while regions outside the angle range travel. Since the received light is buffered by the slope, the brightness is relatively low.

  Therefore, as shown in FIG. 9, when the arc tube 12 is attached to the reflector 11, the light emitted from the angle range formed by the inclined surfaces facing each tungsten electrode 14, 15 is reflected on the inner peripheral surface 11 f of the reflector 11. The reflected portion (the hatched range surrounded by a two-dot chain line in the figure) is a region R having a high light beam density, and the portions other than the region R are regions having a light beam density lower than that of the region R. In addition, reflection is performed on the inner peripheral surface 11f so that the incident angle and the reflection angle are equal to the tangent at the point where the light emitted from the arc tube 12 and the inner peripheral surface 11f intersect.

  When the arc tube 12 is attached to the reflector 11, one end 13 a is inserted into the hole 11 h of the reflector 11, and the axis of the arc tube 12 is aligned with the central axis C passing through the central top portion 11 i of the reflector 11. In this state, the arc tube 12 and the reflector 11 are fixed with the fixing agent 16 so that the vicinity of the center of the chamber portion 13c coincides with the focal point of the reflector 11.

  On the other hand, the heat conducting member 20 that connects the arc tube 12 and the reflector 11 across the space in the reflector 11 is made of copper, and extends radially from a cylindrical outer fitting annular portion 21 provided in the center. While having the extension parts 23-25, the extension end of each extension part 23-25 is connected with the ring-shaped fitting annular part 22. FIG. Further, the heat conducting member 20 is coated with an antioxidant film after polishing the surfaces of the respective parts 21 to 25 to ensure glossiness. In this embodiment, the product called NL110 made by Clariant is used as the antioxidant film. Is used. An antioxidant film made of quartz coating or silicon dioxide can be applied.

  An outer fitting annular portion 21 provided in the center has an inner diameter that is dimensioned so that it can be fitted onto the sealing portion 13d (the portion from the chamber portion 13c to the end portion 13b) on the end portion 13b side where the arc tube 12 protrudes. The length is slightly shorter than the sealing portion 13d. In addition, the extended portions 23 to 25 form curved portions 23a to 25a on the outer peripheral side extending radially outward from the center, and the curved start points 23b (see FIG. 9) of the curved portions 23a to 25a are defined as the region R. It is made to correspond to the point where each extension part 23-25 crosses. In FIG. 9, only the music starting point 23b of the extending part 23 is shown, but the other extending parts 24 and 25 have the same positional relationship as the music starting point 23b.

  Further, the outer fitting annular portion 22 connected to each of the extending portions 23 to 25 has an outer diameter and a width dimension that can be fitted to the fitting surface 11 g of the reflector 11. In this embodiment, the width dimension of the fitting annular portion 22 is about one fifth of the length of the central outer fitting annular portion 21, and this width dimension is equivalent to each of the extending portions 23 to 25. is there. Moreover, the thickness of the external fitting annular part 21, the fitting annular part 22, and each extension part 23-25 which form the heat conductive member 20 is set to the dimension of about 0.5 mm-about 1.0 mm.

  The heat conducting member 20 is attached by fitting the outer fitting annular portion 21 at the center to the sealing portion 13d of the arc tube 12 and fitting the outer fitting annular portion 22 to the fitting surface 11g of the reflector 11. Do. Although not shown in FIG. 9, a fixing agent 16 used for fixing the arc tube 12 and the reflector 11 is interposed between the outer annular portion 21 and the sealing portion 13 d of the arc tube 12. Yes.

  After attaching the heat conducting member 20 in this way, the lead wire d2 on the protruding side of the arc tube 12 is drawn out of the reflector 11 from the hole 11j, and then the explosion-proof glass is placed in the recess 11e of the flange 11b of the reflector 11. 29 is adhered to complete the explosion-proof light source 10. When the light source 10 is turned on, only the extending portions 23 to 25 block the region R having a high light flux density (brightness), so that the irradiation characteristics of the light source 10 are almost deteriorated even when the heat conducting member 20 is attached. I will not let you.

  The completed light source 10 is arranged in the lower duct portion 5 by being supported by a set of support portions 19 in the lower duct portion 5 shown in FIG. 7, and the required connection to the lead wires d1 and d2 is performed. The upper projection 6 is combined with the lower duct 5 to complete the rear projection device 1 shown in FIGS. The light source 10 disposed in the duct 4 is positioned higher than the power supply unit 34 housed in the lower housing 2 in the height direction (see FIGS. 2 and 3).

Next, an image is displayed on the completed rear projection apparatus 1 to describe the state of heat generated in the apparatus and the state of airflow.
First, when the power supply unit 34 starts to supply power to the other units 31, 33, the light source 10, and the like in order to display an image, the units 31, 33, 34 and the light source 10 generate heat. The air inside and the air inside the duct 4 are warmed.

  The amount of heat generated by each unit 31, 33, 34 is the lowest in the optical unit 31 as described above, and thereafter increases in the order of the control unit 33 and the power supply unit 34. A temperature distribution occurs in which the temperature increases. In addition, since the air warmed by the units 31, 33, and 34 is lightened and rises inside the lower housing 2, the direction in which the air inside the lower housing 2 moves and the direction in which the temperature distribution becomes higher are the same. As a result, a rising air flow is generated inside the lower housing 2. In addition, due to the air flow generated in this way and the temperature difference between the inside and outside of the apparatus, cold outside air existing outside the periphery of the air inlet 7 provided below the lower housing 2 enters the inside of the lower housing 2 from the air inlet 7. In the lower housing 2, natural convection occurs in which air that has entered the interior from the air inlet 7 rises.

  On the other hand, the temperature of the glass body 13 rises due to the heat generated in the arc tube 12 in the lit light source 10. There are three forms of heat dissipation in the light source 10: convective heat transfer, radiation, and heat conduction. Among these three forms, heat conduction has the highest efficiency of heat transfer, and the second is radiation. Convective heat transfer consists of a system in which heat is transferred from the arc tube 12 to the reflector 11 through the air confined in the reflector 11 existing around the arc tube 12, and an explosion-proof glass 29 on the front side from the arc tube 12. Heat transfer is performed in two systems in total, where heat is transferred to the heat source.

  Radiation is performed between the arc tube 12 and the reflector 11. In addition, there are two heat paths for heat conduction, and the first heat path is to conduct heat from the end portion 13a of the arc tube 12 on the attachment side to the reflector 11 to the reflector 11 through the fixing agent 16. In the second heat path, heat is conducted from the projecting side sealing portion 13 of the arc tube 12 to the reflector 11 through the heat conducting member 20. The arc tube 12 has the highest temperature in the chamber portion 13c, and the heat of the chamber portion 13c is transmitted to the sealing portion 13d on the protruding side, so that the temperature of the sealing portion 13d rises. The heat of the portion 13d is moved to the reflector 11 through the heat conducting member 20, and the temperature rise of the sealing portion 13d is suppressed to extend the life of the arc tube 12.

  In addition, the reflector 11 from which heat is transferred by convective heat transfer, radiation, and heat conduction is covered with the coating film 17 on the inner peripheral surface 11f. Is radiated from the reflector 11 to the air in the duct 4. Further, heat radiation in the light source 10 is radiated from the front explosion-proof glass 29 to the air in the duct 4 in addition to the reflector 11. The air around the light source 10 is warmed by the heat radiation by the light source 10.

  Since the warmed air is blocked from the outside by the duct 4, it is not mixed with the outside air, but is filled with only warm air and filled in the duct 4. Due to the mass difference, buoyancy based on the so-called chimney effect is generated inside the duct 4. When this buoyancy exceeds the resistance to the inside of the duct 4, an air flow directed upward of the duct 4 is generated. Further, since the heat radiation from the light source 10 continues while the light source 10 is turned on, an upward air flow is also continuously generated. Therefore, a negative pressure is generated at a position below the light source 10 of the duct 4. Due to this negative pressure, the lower opening 5 a of the duct 4 sucks air inside the lower housing 2, and an air flow toward the inside of the duct 4 is generated.

  As a result, as indicated by the arrows in FIGS. 2 and 3, in the entire rear projection apparatus 1, the cold air sucked into the inside of the lower housing 2 from the air inlet 7 generates heat from the units 31, 33, and 34. Then, the air rises while being warmed, and then enters the inside of the duct 4 through the lower opening 5a of the duct 4, and then the air that has entered the duct 4 is further warmed by the light source 10 and rises. A series of large flows are formed so as to be exhausted from the upper opening 6a at the upper end of the upper end.

  Since each unit 31, 33, and 34 is appropriately cooled by this large air flow, stable operation is ensured without providing a cooling fan. Further, since the heat source is taken away from the outer surfaces of the reflector 11 and the explosion-proof glass 29 by the air flow guided by the duct 4 and rising as needed, the required cooling performance is ensured and the temperature range is maintained even without a cooling fan. Lights can continue. Therefore, the rear projection apparatus 1 of this embodiment can ensure normal usability without a cooling fan, and can eliminate various noises generated by the rotation of the cooling fan by eliminating the cooling fan.

  During the lighting of the light source 10, the temperature in the chamber portion 13 c of the arc tube 12 is suppressed from 800 ° C. to 1000 ° C. or less due to heat conduction by the heat conducting member 20, and the temperature of the sealing portion 13 d on the protruding side is 400 ° C. The following can be suppressed. Further, while the light source 10 is turned on, the heat conducting member 20 (particularly the extending portions 23 to 25) is irradiated with the reflected light from the reflector 11, but the surface of the heat conducting member 20 is ensured to be glossy by polishing. Therefore, the rate at which the heat conducting member 20 absorbs heat is reduced by reflecting the irradiated light on the surface. And since the surface of the heat conductive member 20 is coat | covered with the antioxidant film | membrane, it is preventing that the surface becomes cloudy and a reflective characteristic falls.

  In addition, although the heat conductive member 20 is suppressing the temperature rise by reflection on the surface, the temperature of the copper heat conductive member 20 itself rises due to long-time irradiation and heat conduction, and each of the extending portions 23 to 25. In the radial direction, thermal expansion occurs, but the radial extension due to the thermal expansion is absorbed by the curved portions 23a to 25a and converted into the extension in the circumferential direction, so that an unnecessary stress is applied to the arc tube 12. Nor.

  Further, the rear projection device 1 according to the present invention is not limited to the above-described embodiment, and various modifications can be applied. First, the duct 4 may be applied to a shape other than that shown in FIGS. 1 to 3, for example, the cross-sectional shape is not substantially circular, and can be a polygon more than a square, When the cross-sectional shape is changed, the layout may be such that it fits within the outer peripheral shape of the lower housing 2 and the upper housing 3. Furthermore, in addition to extending the duct 4 in a straight line, the duct 4 can be tilted from the vertical direction, or can be curved instead of a straight line. The degree of freedom of arrangement of the units 31, 33, 34, etc. can also be improved.

  FIG. 12 shows the appearance of a rear projection apparatus 1 ′ according to a modified example. In this modified example, the lower duct part 5 ′ constituting the duct 4 ′ is extended downward as compared with the lower duct part 5 shown in FIG. An opening 5a 'is formed in the lower peripheral wall exposed outward. By doing so, a large amount of cool air outside the apparatus can be directly taken into the duct 4 'from the opening 5a' at the lower end, and the air flow generated by the chimney effect in the duct 4 'is further strengthened. The cooling efficiency of the light source 10 can be improved. The duct 4 ′ is not communicated with the inside of the lower housing 2 ′, and the air flow in the duct 4 ′ and the lower housing 2 ′ is made independent so as not to be affected by the other flow. Also good. In this case, it is preferable to form an exhaust port at an upper portion of the lower housing 2 ′.

  Further, a light-transmitting member such as glass may be fitted into the light-transmitting portion of the light source 10 constituted by the prepared holes 5b and the upper holes 6b shown in FIG. By doing so, the airflow on the front side of the light source 10 is not disturbed by the influence of the openings of the lower hole 5b and the upper hole 6b, and the airflow rises more smoothly. Heat dissipation can be improved.

  FIG. 13 shows a reflector 51 of a modification applied to the light source 10, and the reflector 51 is characterized in that a large number of radiating fins 53a to 53i protrude from the outer peripheral surface 51k of the concave mirror part 51a. In addition, although the infrared heat conversion layer 57a, the gloss buffer layer 57b, and the visible light reflection layer 57c are provided on the inner peripheral surface 51f of the concave mirror portion 51a, each layer can be omitted. By providing the radiation fins 53a to 53i in this way, the reflector 51 can greatly expand the contact area with the air existing in the surroundings and improve the heat radiation characteristics.

When the heat radiation fins 53a to 53i or the layers 57a to 57c forming the coating film can secure sufficient heat radiation, the heat conducting member 20 may be omitted from the light source 10. In addition, when the heat radiation fins 53a to 53i or the heat conducting member 20 can ensure sufficient heat dissipation, the layers 57a to 57c forming the coating film can be omitted. When the coating film is formed, the inner peripheral surfaces 11f and 51f of the reflectors 11 and 51 themselves are mirror-polished, and a low refractive material such as SiO ₂ and a high refractive material such as TiO ₂ are alternately deposited. It is important to increase the reflection efficiency by forming the inner peripheral surfaces 11f and 51f with a body multilayer film or by depositing a metal such as aluminum or silver on the inner peripheral surfaces 11f and 51f. Further, the explosion-proof glass 29 may be omitted from the light source 10, and in this case, since air flows into the reflector, the cooling performance for the light source 10 can be further improved.

  2 and 3 may be provided with a guide duct connecting the air inlet 7 and the lower opening 5a in order to smoothly guide the airflow from the air inlet 7 to the lower opening 5a of the duct 4. In this case, it is preferable to arrange any or all of the optical unit 31, the control unit 33, and the power supply unit 34 in the guide duct so that outside air enters the guide duct from the intake port 7 by natural convection. .

  In addition, when each unit 31, 33, 34 cannot be arrange | positioned like FIG.2, 3 etc. by the dimension, shape, etc. of the rear projection apparatus 1, arrangement | positioning can also be changed suitably, but in that case, each unit is changed. It is preferable that at least one of 31, 33, and 34 is arranged between the light source 10 and the air inlet 7 to generate natural convection that rises in the lower housing 2 and guides air into the duct 4. It is. Furthermore, due to the space, shape, etc. inside the lower housing 2, the formation of a suitable natural convection is weak, and when the units 31, 33, 34 and the light source 10 cannot be sufficiently cooled, a small size with less noise generation These fans may be provided in an auxiliary manner inside the lower housing 2 or inside the duct 4.

It is a perspective view from the back side of a rear projection device concerning an embodiment of the present invention. It is a rear view of the rear projection device of an embodiment. It is a side view of the rear projection device of an embodiment. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a perspective view which shows the positional relationship of the inside of a lower housing | casing, and a duct. It is a principal part perspective view of a lower duct part. It is a perspective view which shows the decomposition | disassembly state of a light source. It is sectional drawing of a light source. It is an expanded sectional view of a reflector. (A) is the schematic which shows the internal structure of a light guide cabinet part, (b) is the schematic which shows the internal structure of a main body cabinet part, (c) is the schematic which shows the internal structure of a projection cabinet part. It is a perspective view from the back side of the rear projection device of a modification. It is sectional drawing of the reflector of a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rear projection apparatus 2 Lower housing | casing 3 Upper housing | casing 4 Duct 5 Lower duct part 5a Lower opening 5b Lower hole 6 Upper duct part 6a Upper opening 6b Upper hole 7 Inlet 10 Light source 11 Reflector 12 Light emitting tube 17 Covering film 20 Heat Conductive member 31 Optical unit 33 Control unit 34 Power feeding unit 53a to 53i Radiation fin

Claims (15)

A light source in which an arc tube is arranged in a concave reflector, an optical unit that forms modulated light according to an image based on light emitted from the light source, a screen on which modulated light emitted from the optical unit is projected, and an air flow In a rear projection device comprising a duct for guiding
The light source is disposed inside the duct;
The rear projection apparatus according to claim 1, wherein a light passing portion through which light emitted from the light source passes is formed on a peripheral wall of the duct.   The rear projection apparatus according to claim 1, wherein the duct includes a support portion that supports the light source disposed therein.   The rear projection apparatus according to claim 1, wherein the duct extends from a lower part of the apparatus to an upper part of the apparatus.   The rear projection apparatus according to claim 3, wherein an upper end of the duct is opened so that the inside of the duct communicates with the outside of the apparatus.   The rear projection apparatus according to claim 3 or 4, wherein a lower end of the duct is opened so that the inside of the duct communicates with the inside of the apparatus.   6. The rear projection apparatus according to claim 3, wherein a cross-sectional shape in a direction perpendicular to the extending direction of the duct is a polygon of a quadrangle or more or a substantially circular shape.   The rear projection apparatus according to claim 1, wherein the light source includes a heat conductive member that connects the reflector and the arc tube across the space in the reflector.   The rear projection apparatus according to claim 1, wherein the light source includes a coating film that covers a reflection surface on an inner peripheral side of the reflector.   The rear projection apparatus according to claim 1, wherein the light source includes a heat radiating fin on an outer peripheral surface of the reflector.   The rear projection apparatus according to claim 1, wherein the light source includes a translucent member that closes an opening on a reflection side of the reflector. A housing for housing the optical unit;
The rear projection apparatus according to claim 1, wherein an air inlet is formed at a position below the light source of the housing. The housing contains a power supply unit that supplies power to the light source and the optical unit,
The rear projection apparatus according to claim 11, wherein the power supply unit is disposed between the light source and the air inlet in a height direction. The housing contains a control unit that performs control processing related to formation of modulated light of the optical unit,
The rear projection apparatus according to claim 11, wherein the control unit is disposed between the light source and the air inlet in a height direction. The optical unit is disposed between the light source and the air inlet in the height direction,
The rear projection apparatus according to claim 11, further comprising a reflecting member that guides light emitted from the light source to the optical unit. The housing contains a power supply unit that supplies power to the light source and the optical unit, and a control unit that performs control processing related to formation of modulated light of the optical unit,
The power supply unit is disposed between the light source and the air inlet in a height direction,
The control unit is disposed between the power supply unit and the air inlet in the height direction,
The optical unit is disposed between the control unit and the air inlet in the height direction,
The rear projection apparatus according to claim 11, further comprising a reflecting member that guides light emitted from the light source to the optical unit.

Images