JP2016045260A - Image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which: various discharge lamps are used as a light source of a projection type display device; the temperature of an upper part of a lamp becomes higher than that of a lower part during lighting, a cooling structure to reduce a difference in temperature between the upper part and lower part of the lamp is required in order to extend the life of the lamp; however, since the position of the upper part of the lamp is changed accompanying the installation state of the projection type display device, an appropriate temperature of the lamp cannot be satisfied with a single cooling structure depending on a projection state and the life of the lamp is reduced.SOLUTION: A duct including a plurality of air channels is rotated according to an installation state of a projection type display device and sends a cooling air always in a direction parallel to an installation surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a lamp that is a light source of an image projection apparatus such as a liquid crystal projector, and more particularly to a method for cooling the lamp.

  In recent years, demand for image projection apparatuses typified by liquid crystal projectors is rapidly expanding. As demand grows, there are various uses such as presentations, home theaters, and planetariums. In these applications, in addition to stationary installation and ceiling installation, upward installation and downward installation are one anticipated demand.

  Further, a lamp is used as a light source of the liquid crystal projector, and this lamp has a lifetime similar to an incandescent lamp used as a normal light source. One factor in lamp life is the temperature difference between the lamp bulb and the lamp bulb. During lighting, the upper part of the lamp bulb is hotter than the lower part of the lamp bulb, and a cooling structure that narrows the temperature difference between the upper part of the lamp bulb and the lower part of the lamp bulb is necessary to extend the life of the lamp.

  However, since the position above the lamp changes with the installation state of the projection display device, the single cooling structure does not satisfy the appropriate temperature of the lamp depending on the projection state, and the lamp life is shortened.

  As a method for solving the above-described problems, configurations as disclosed in the patent documents described below have been proposed. The image projection apparatus described in Patent Document 1 uses a posture sensor to control the rotation direction of the fan so that the exhaust direction is always directed from the heaven to the ground according to the posture. In addition, the image projection apparatus described in Patent Document 2 uses two or more light sources, turns on only the light source whose emission direction of irradiation light is horizontal, and adjusts the direction with a half mirror according to the installation state. The light is guided to the optical path.

JP 2010-266569 A JP 2009-229576 A

  As shown in Patent Document 1, in the configuration in which the rotation direction of the fan is always controlled in the direction in which the exhaust direction is directed from the top to the ground according to the posture by using the posture sensor, However, cooling air can always be blown from the upper part of the lamp bulb to the lower part of the lamp bulb, but in upward installation or downward installation, cooling air is blown in parallel to the installation surface. The temperature difference will change.

  As shown in Patent Document 2, by using two or more light sources, only the light source in which the emission direction of irradiation light is horizontal is turned on according to the installation state, and the direction is adjusted by a half mirror, and light is transmitted to a common optical path. In the configuration that guides the light, it is necessary to change the traveling direction of the light by the half mirror, and there is a concern that the illuminance decreases.

  Accordingly, an object of the present invention is particularly related to cooling of the lamp, and is provided with a mechanism for always cooling the lamp in the horizontal direction with respect to the installation surface regardless of the posture, thereby extending the life of the lamp.

Therefore, in order to achieve the above problem, the configuration of the image projection apparatus of the present invention is
A lamp as a light source; a lamp housing provided in an exterior for fixing the lamp; an intake port for sucking a cooling medium for cooling the lamp; and a cooling medium for cooling the lamp In a projection display apparatus using a light emitted from the lamp, the lamp cooling duct has two paths, and an exhaust port for exhausting and a lamp cooling duct for guiding a cooling medium for cooling the lamp in a predetermined direction. The above-described intake air passage, the lamp cooling duct has two or more exhaust air passages, and the lamp cooling duct has a mechanism that rotates about the optical axis of the lamp. It passes through the air passage.

  The outer shape of the lamp cooling duct is a circle centered on the optical axis of the lamp.

  Further, the lamp housing portion has four openings each having a phase difference of 90 degrees.

  Further, the opening of the lamp housing part has a mechanism for closing two places that are 180 degrees out of phase when the lamp cooling duct is attached.

  According to the present invention, it is possible to blow the lamp cooling air in a direction parallel to the installation surface with respect to the installation surface, the ceiling installation, the upward installation, the downward installation, and the orientation of the temperature balance above and below the lamp bulb. It can be made constant regardless.

  Furthermore, according to the present invention, it is possible to perform effective lamp cooling at low cost without requiring additional components such as a posture sensor and a half mirror.

  Furthermore, according to the present invention, since the exhaust port described above is only required in one place, the degree of design freedom is not impaired.

The top view of the image projector in Embodiment 1 of this invention 1 is an optical configuration diagram of an image projection apparatus according to Embodiment 1 of the present invention. 1 is a cooling configuration diagram of an image projection apparatus according to Embodiment 1 of the present invention. Detailed view of natural convection of the lamp Detailed view of cooling air and natural convection inside the lamp by horizontal cooling on the installation surface Detailed view of cooling air and natural convection inside the lamp by vertical cooling with respect to the installation surface Lamp unit cooling configuration perspective view in Embodiment 1 of the present invention Lamp unit cooling configuration sectional view at the time of stationary installation in Embodiment 1 of the present invention Lamp unit cooling structure sectional view at the time of upward installation in Embodiment 1 of the present invention Lamp unit assembly drawing at the time of stationary installation in Embodiment 1 of the present invention (before assembly) Lamp unit assembly drawing (after assembly) at the time of stationary installation in Embodiment 1 of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  An image projection apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

(overall structure)
In FIG. 1, α is an illumination optical system that receives light from the lamp 1. β is a color separation / synthesis optical system including a liquid crystal panel for three colors of R, G, and B on which light emitted from the illumination optical system is incident. A lamp 1 is a light source. A lamp cooling unit 2 includes a lamp 1 and a lamp holder 50 described later and a lamp bulb cooling duct described later. Reference numeral 3 denotes a projection lens unit for projecting an image on a screen (projected surface) (not shown) by receiving light emitted from the color separation / synthesis optical system β. Reference numeral 4 denotes an optical box that houses a lamp unit 19, an illumination optical system α, and a color separation / synthesis optical system β, which will be described later, and to which the projection lens unit 3 is fixed.

  5 is a ballast unit. The ballast unit 5 includes a power source (not shown) and a ballast power source that is electrically connected to the power source and controls lighting of the lamp 1. Reference numeral 6 denotes a power source, which is incorporated in an exterior cabinet 13 described later and is electrically connected to the power source / ballast unit 5 to supply power to the housing.

  An optical cooling fan 7a cools a later-described reflective liquid crystal display element 48G for G of the color separation / synthesis optical system β by air sucked from outside air inlet 17 which will be described later provided in the exterior cabinet 13. Reference numeral 7b denotes air that has taken in outside air from an air inlet 17 (to be described later) provided in the exterior cabinet 13, and an R reflective liquid crystal display element 48R (to be described later) and a reflective liquid crystal display element 48R (to be described later) of the color separation / combination optical system β. To cool the optical cooling fan.

  Reference numeral 8 denotes an RGB duct for smoothly sending outside air flowing in from the air inlet 17 to the color separation / synthesis system β using the optical cooling fans 7a and 7b. Reference numeral 9 denotes a lamp cooling fan for sending the blowing air to the lamp cooling unit 1 to cool the lamp 1. Reference numeral 10 denotes a lamp duct for holding the lamp cooling fan 9 and sending cooling air to the lamp 1. Reference numeral 11 denotes an electric exhaust fan that exhausts air exhausted from an optical cooling duct 15 described later to the outside of the housing and exhausts air around an RGB substrate 18 described later.

  Reference numeral 12a denotes a lamp cooling fan A that sucks outside air from an inlet 17 to be described later and cools the periphery of the lamp 1. Reference numeral 12b denotes a lamp exhaust fan B which is blown from the lamp cooling fan 9 and exhausts the heated air from an exhaust lid which describes the air. 13 is an exterior cabinet for storing the optical box 6 and the like. An optical cooling fan 14 cools the polarization conversion element by blowing air in the housing to the polarization conversion element described later. Reference numeral 15 denotes an optical cooling duct for holding the optical cooling fan 14 and sending cooling air to the polarization conversion element.

  Reference numeral 16 denotes an exhaust lid, which has an exhaust port for exhausting air in the housing and is configured to be opened and closed from the exterior cabinet. Reference numeral 17 denotes an air inlet including an air filter (not shown) that suppresses dust from entering the housing when inhaling outside air. Reference numeral 18 denotes an RGB substrate for controlling the color separation / synthesis optical system.

(Optical configuration)
Next, a projection equipped with a reflective liquid crystal display element (an image forming element such as a reflective liquid crystal panel) constituted by the light source lamp 1, the illumination optical system α, the color separation / synthesis optical system β, and the projection lens unit 5 described above. The optical configuration of the type image display apparatus will be described with reference to FIG.

  In FIG. 2, 31 is a lamp bulb that emits white light in a continuous spectrum. Reference numeral 32 denotes a reflector that condenses light from the lamp bulb 31 in a predetermined direction, and the light source lamp 1 is formed by the lamp bulb 31 and the reflector 32. Reference numeral 32 denotes an explosion-proof convex lens having a function of condensing light from the light source lamp 1 as described above. 33a is a fly-eye lens A, and 33b is a fly-eye lens B, which is a light beam splitting unit that splits light from the light source lamp 1 into a plurality of light beams.

  Reference numeral 34 denotes an ultraviolet absorption filter, which is a color selective filter for removing light (ultraviolet rays) on the short wavelength side from the light from the light source lamp 1. Reference numeral 35 denotes a polarization conversion element having a polarization conversion function for converting non-directional light (unpolarized light) from the lamp 1 into predetermined polarized light. Reference numeral 36 denotes a total reflection mirror for converting the optical axis. 37a is a condenser lens A, 37b is a condenser lens B, and a condenser means for illuminating a plurality of light beams divided by the fly-eye lens A33a and the fly-eye lens B33b on a reflective display element. The illumination optical system α is configured as described above.

  A dichroic mirror 38 reflects light in the blue (B) and red (R) wavelength regions and transmits light in the green (G) wavelength region. A trimming filter 39 is a means for limiting the wavelength range used by the light in the R band in order to increase the color purity of R. 40 is a wire grid polarizing plate and is a reflection type polarization selection means. Reference numeral 41 denotes a wavelength-selective phase plate that converts the polarization direction of light in a predetermined wavelength range by color selection. Reference numeral 42 denotes a first polarization beam splitter having a polarization separation surface. 43 is a second polarization beam splitter having a polarization separation surface. Reference numeral 44 denotes a combining prism that acts on the blue (B) and green (G) dichroic, and acts on the red (R) in the same manner as the polarizing beam splitter.

  45 is a blue polarizing plate which is blue (B) polarization selection means. 46 is a green polarizing plate which is a green (G) polarization selection means. 47R, 47G, and 47B are an R quarter-wave plate, a G quarter-wave plate, and a B quarter-wave plate, respectively. Reference numerals 48R, 48G, and 48B denote a reflective liquid crystal display element for R, a reflective liquid crystal display element for G, and a reflective liquid crystal display element for B that reflect incident light and modulate the image, respectively. The color separation / synthesis optical system β is constituted by the reflective liquid crystal display elements of the respective colors 48R, 48G, and 48B from the dichroic mirrors 38 described above.

(Cooling configuration)
Next, a cooling configuration in the image projection apparatus of the present embodiment will be described with reference to FIG. As described above, the image projection apparatus includes four cooling fans and two exhaust fans. A flow path constituted by a total of six cooling and exhaust fans is indicated by arrows in FIG. The details of the air path will be described below with the solid arrows in FIG. 3 as intake air and the broken arrows as exhaust gas.

  Regarding the cooling of the optical element, the outside air flows from the air inlet 17 by the rotation of the optical cooling fan 7a and the optical cooling fan 7b. The air flowing out of the optical cooling fan 7a cools the G reflective liquid crystal display element 48G and the color select 41. The air flowing out of the optical cooling fan 7b cools the R-use reflective liquid crystal display element 48R and the B-use reflective liquid crystal display element 48B. The air that has cooled each reflective liquid crystal display element is sucked into the optical cooling fan C14. The air flowing out from the optical cooling fan C14 cools the polarization conversion element 35. The air that has cooled the polarization conversion element 35 is exhausted out of the housing by the electric exhaust fan 11. The electric exhaust fan also plays a role of cooling the heat generated from the RGB substrate 18 by intake air and exhausting it outside the housing.

  Next, with respect to the cooling of the lamp, the outside air flows from the intake port 17 by driving the lamp cooling fan 9 and the lamp exhaust fan 12. The air flowing out from the lamp cooling fan 9 cools the lamp arc tube 31 and is exhausted from the exhaust lid 16 to the outside of the housing. The air flowing out from the lamp exhaust fan 12 exhausts the air around the lamp 1 through the lamp exhaust air passage 2b from the exhaust lid 16 to the outside of the casing. The intake and exhaust of the lamp exhaust fan also plays a role of exhausting heat generated from the ballast unit 5 and the power source 6 to the outside of the housing.

  Note that each cooling fan and exhaust fan are driven for a certain period of time after the lamp is extinguished, and have a function of reducing the temperature of the lamp and discharging the air in the housing.

(Lamp cooling)
Next, the details of the wind direction when the lamp bulb is cooled will be described with reference to FIGS. In FIG. 4, the upper side with respect to the paper surface shows the lamp bulb above, and the lower side shows the lamp bulb below. A solid line arrow indicates natural convection when the lamp within the reflector 32 emits light. When the lamp emits light, upward airflow is generated from the lower part of the lamp bulb to the upper part of the lamp bulb, and is distributed to the left and right at the top of the reflector and descends.

  FIG. 5 shows a case where the lamp bulb is cooled in parallel to the installation surface. The cooling air that has blown perpendicularly to the natural convection and has reached the updraft cools the lamp bulb, and the cooling air that has reached the downdraft cools the lamp bulb below.

  FIG. 6 shows a case where the lamp bulb is cooled perpendicular to the installation surface. The natural convection is blown from the opposite direction, and the cooling air does not reach the upper part of the lamp bulb, but the air descends and cools only the lower part of the lamp bulb. Therefore, the temperature above the lamp bulb is high, the temperature below the lamp bulb is low, and the temperature difference between the lamp bulb and the lamp bulb is large.

  Next, the lamp cooling according to the present invention will be described with reference to FIGS. FIG. 7 is a perspective view when the lamp cooling unit 2 is installed and installed. The cooling air sent from the lamp cooling fan passes through the lamp duct 10, passes through the lamp bulb cooling duct 52, the cooling air flows into the reflector 32, cools the lamp bulb 31, and is cooled by the lamp exhaust fan A12a. It passes through the cooling duct 52 and is exhausted out of the housing.

  FIG. 8 is a detailed view when the lamp cooling unit 2 is installed stationary. The cooling air shown by the solid line flows parallel to the installation surface with respect to the lamp bulb, with the lower surface of the paper as the installation surface.

  FIG. 9 is a detailed view when the lamp cooling unit 2 is installed upward. The lamp bulb cooling duct 52 is rotated 45 degrees counterclockwise with respect to the stationary installation of FIG. The cooling air shown by the solid line flows parallel to the installation surface with respect to the lamp bulb, with the lower surface of the paper as the installation surface.

  FIG. 10 is a detailed view of the lamp bulb cooling duct 52 before installation at the time of installation. The lamp holder opening / closing part 51 attached to the lamp holder 50 includes a spring member, and has a structure that does not block the opening of the lamp holder 50 as shown in FIG. 10 before the lamp bulb cooling duct 52 is assembled.

  FIG. 11 is a detailed view after the lamp bulb cooling duct 52 is assembled at the time of installation. When assembled, the lamp bulb cooling duct protrusion 52a pushes the lamp holder opening / closing part 52a, so that the two lamp holder opening / closing parts 52a that are symmetrical by 180 degrees block the opening of the lamp holder 50. This prevents the exhaust air from leaking and staying from above or below the lamp.

1 lamp, 2 lamp cooling unit, 3 projection lens unit, 4 optical box,
5 Ballast unit, 6 Power supply, 7a Optical cooling fan A, 7b Optical cooling fan B,
8 RGB ducts, 9 lamp cooling fans, 10 lamp ducts,
11 Power supply exhaust fan, 12a Lamp exhaust fan A, 12b Lamp exhaust fan B,
13 exterior cabinet, 14 optical cooling fan C, 15 optical cooling duct,
16 Exhaust lid, 17 Inlet, 18 RGB board, 30 Explosion-proof convex glass,
31 lamp bulb (light source), 32 reflector, 33a fly eye A,
33b fly eye B, 34 ultraviolet absorption filter, 35 polarization conversion element,
36 Total reflection mirror, 37a Condenser lens A, 37b Condenser lens B,
38 Dichroic mirror, 39 Trimming filter,
40 wire grid polarizer, 41 color select,
42 a first polarizing beam splitter, 43 a second polarizing beam splitter,
44 synthetic prism, 45 polarizing plate for blue, 46 polarizing plate for green,
1/4 wavelength plate for 47R R, 1/4 wavelength plate for 47G G, 1/4 wavelength plate for 47BB,
48RR reflective liquid crystal display element, 48GG reflective liquid crystal display element,
48B reflective liquid crystal display element for B, 50 lamp holder,
51 Lamp holder opening / closing part, 52 Lamp bulb cooling duct,
52a Lamp bulb cooling duct protrusion, α illumination optical system, β color separation / synthesis optical system

Claims (5)

A lamp as a light source;
A lamp housing provided in the exterior for fixing the lamp;
An air inlet for sucking a cooling medium for cooling the lamp;
An exhaust port for exhausting a cooling medium for cooling the lamp;
A lamp cooling duct for guiding a cooling medium for cooling the lamp in a predetermined direction;
In a projection display device using light emitted from the lamp,
The lamp cooling duct has two or more intake air paths,
The lamp cooling duct has two or more exhaust air paths,
A projection type display device comprising:   2. The projection display device according to claim 1, wherein the lamp cooling duct has a mechanism for rotating about the optical axis of the lamp.   2. The projection display device according to claim 1, wherein an outer shape of the lamp cooling duct is a circle centered on an optical axis of the lamp.   The projection display device according to claim 1, wherein the lamp housing portion has four openings each having a phase difference of 90 degrees.   2. The projection type display device according to claim 1, wherein the opening of the lamp housing portion has a mechanism for closing two opposing portions when the lamp cooling duct is attached.