JP3705138B2 - LCD projection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal projection apparatus that enlarges and projects an image of a liquid crystal panel, and more particularly to a liquid crystal projection apparatus that has a cooling mechanism for projecting using two lamps.
[0002]
[Prior art]
Conventionally, an apparatus for enlarging and projecting an image of a liquid crystal panel using a light source such as a metal halide or an ultrahigh pressure mercury lamp has been put on the market. In this case, light emitted from a light source is condensed on a liquid crystal panel via a mirror or the like, and is projected onto a screen through a projection lens. Recently, high-luminance lamps have emerged so that projected images can be seen on a large screen even in a bright room, and lamps have also been increased in output and point light sources to improve the light utilization rate of optical systems. In general, an optical system using these lamps is often configured as shown in FIG. The main configuration of the three-plate type liquid crystal projector optical system is that the light from the lamp (light source) 120 is separated into red, green, and blue using a plurality of mirrors 122 and is incident on the liquid crystal panel (unit) 126 to obtain an X prism 128. In this method, the image is synthesized and is enlarged and projected by the projection lens 127.
[0003]
The liquid crystal panel unit is provided with three front and rear incident side polarizing plates and three outgoing side polarizing plates. By controlling the potential on and off of each pixel, the light quantity control of all white, all black, and halftone is performed. Color synthesis is performed for each pixel. Projectors with an optical system that uses two or more lamps have also appeared as projectors that pursue even greater brightness. As a basic configuration of the projection optical system showing these two-lamp illuminations, for example, there are configurations of Japanese Patent Laid-Open Nos. H5-29322 and H5-49569 shown in FIGS. In general, the arc tube 20 is aligned and fixed in the vicinity of the focal point of the ellipsoidal or paraboloidal reflecting mirror 121, and the light flux from the arc tube has a field lens 123 and a condensing system component 124 having an integrator function for uniformly illuminating the screen. Then, the liquid crystal panel 126 is illuminated, color-combined by the cross prism 128, and then enlarged and projected onto the screen by the projection lens 127.
[0004]
In the case of the two-lamp combination shown in FIG. 7, the illumination structure is the same as that of the one-lamp type by combining the lamp lights with a mirror 128 that combines them. An outline of a general cooling structure with two lamps will be described. In many cases, the lamp is forcibly cooled by a plurality of fans 130 from the rear of the lamp in order to keep the upper portion of the arc tube 120 at about 950 ° C. or lower and the seal portion at 350 ° C. or lower. In general, in many cases, one lamp is cooled by one fan and immediately exhausted outside.
[0005]
[Problems to be solved by the invention]
As described above, in the case of the two lighting system, a cooling structure using one fan for each lamp from the rear is generally adopted, and it is intended to make the lamp cooling with two lamps and the cooling structure of the entire set compact. The internal temperature increased, and the fan was generally provided near the exhaust port to cool the lamp, which caused a problem of noise reduction. Therefore, the authors have proposed a cooling structure of a two-lamp system in Japanese Patent Application Laid-Open No. H11-008775 (FIGS. 9 and 10), but in this system, there is a space for using general-purpose inexpensive parts such as an axial fan. In addition, since the fan sound is immediately at the exhaust port, the fan sound leaked greatly to the outside, and it was difficult to reduce the noise only by reducing the rotational speed of the fan. Therefore, there has been a demand for a structure in which the number of rotations of the fan is suppressed, heat is not stored inside the set, and sound is silenced inside the main body.
[0006]
The present invention solves the above problems, and in a lamp cooling structure of a liquid crystal projector having a plurality of, for example, two-lamp optical systems, the lamp exhaust heat has a constant ventilation path, and the ventilation path from the heat source is an optical component, circuit board It is an object of the present invention to provide a quiet liquid crystal projection apparatus in which heat from a heat source is efficiently exhausted to the outside at a constant distance from the fan, and the fan rotation sound is hard to hear. In order to keep quiet, exhaust is provided on the front of the projector, so that fluctuations (hot flame phenomenon) due to hot air generated on the screen are likely to occur when projected. An object is to provide a projection apparatus.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a liquid crystal projection apparatus according to the present invention includes two lamps each having an arc tube fixed in the vicinity of a focal position of a reflecting mirror having a concave reflecting surface, a temperature increase of the lamp, and a temperature increase inside the main body. Two cooling means for holding the light, reflecting means for reflecting light from the two lamps in a predetermined direction, collimating means for making the light substantially parallel light by the reflecting means, and making the two lamps red, blue and green Color separating means for separating; a liquid crystal panel that modulates each of the red, blue, and green light; a combining optical means that combines light modulated on the liquid crystal panel; a projection lens that projects the combined light; and the lamp; An optical case for holding the cooling means, the collimating means, the liquid crystal panel, the color separating means, the combining optical means, the projection lens, etc., and holding the optical case at the upper part, A base member provided with two air passages for guiding each hot air coming out of the two lamps to the lower part by the rejection means and flowing independently along the two predetermined guide grooves on the projection lens side; and the optical case, It is characterized by comprising a main body case containing the cooling means and the base member. In addition, the air passage for exhausting air from the discharge port of the cooling means to the outside of the main body case and the louvers for determining the air direction are provided on the left and right in the same direction as the projection lens, and the louvers are inclined obliquely forward and away from the projection lens. It was characterized by the configuration. Further, the left and right discharge ports are provided at substantially the same height as the projection lens.
[0008]
With these configurations, in the lamp cooling structure of a liquid crystal projector having a two-lamp optical system, the lamp exhaust heat has a constant ventilation path, and the ventilation path from the heat source is separated from the optical components and the circuit board and from the heat source. By using a structure that efficiently exhausts the heat to the outside at a certain distance from the fan, a quiet liquid crystal projection device that is difficult to hear fan rotation sound can be provided. In addition, by providing exhaust on the front of the projector for quietness, fluctuations (hot flame phenomenon) due to hot air generated on the screen when projected are likely to occur, but since exhaust air is guided to the left and right, it can be suppressed.
[0009]
Even when the above two lamps are used, a high-efficiency and noise-free liquid crystal projection apparatus in which the optical unit and the circuit system do not increase in temperature is obtained.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention, there are two lamps in which an arc tube is fixed in the vicinity of the focal position of a reflecting mirror having a concave reflecting surface, and two cooling means for suppressing the temperature rise of the lamp and the temperature inside the main body. Reflecting means for reflecting light from the two lamps in a predetermined direction; collimating means for making the light substantially parallel light by the reflecting means; and color separation means for separating the two lamps into red, blue and green, A liquid crystal panel that modulates each of the red, blue, and green light, a combining optical unit that combines the modulated light on the liquid crystal panel, a projection lens that projects the combined light, the lamp, the cooling unit, and the collimating unit An optical case for holding the liquid crystal panel, the color separating means, the combining optical means, the projection lens, etc., and holding the optical case at the top, and the cooling means A base member provided with two air passages for guiding each hot air coming out to the lower part and flowing independently along two predetermined guide grooves on the projection lens side, the optical case, the cooling means, and the base member A liquid crystal with a cooling structure that provides a constant ventilation path for the exhaust heat of the lamp, and smoothly exhausts the heat from the heat source without increasing the temperature of the optical components and circuit components, because it is composed of the enclosed main body case. A projection device can be obtained.
[0011]
In the second aspect of the invention, the air passage for exhausting air from the discharge port of the cooling means to the outside of the main body case and the louvers for determining the air direction are provided on the left and right in the same direction as the projection lens. Since the projector is tilted in a diagonally forward direction away from the main body, it is possible to obtain a quiet two-lamp liquid crystal projection device in which a fan rotation sound is difficult to hear because the exhaust port is reversed in a general way of viewing images from the rear.
[0012]
In the third aspect of the invention, since the left and right discharge ports are provided at substantially the same height as the projection lens, the exhaust air is guided to the left and right, and the heated wind rises so that air convection occurs in front of the projection lens. It becomes difficult to eliminate the air fluctuation (hot flame phenomenon) in front of the lens due to front exhaust.
[0013]
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0014]
(Embodiment)
FIG. 1 is an external perspective view showing the entire liquid crystal projection apparatus according to an embodiment of the present invention, and FIG. 2 is an external perspective view of the exhaust port of FIG. FIG. 3 is a perspective view showing the basic structure of the present invention in FIG. 1, with the exterior parts, the optical unit, etc. removed, showing the base member, the lamp, and the exhaust port. FIG. 4 is a base member as seen from the back side of FIG. It is a perspective view which shows a cooling means, a ventilation path, and an exhaust port. FIG. 5 is a perspective view similar to FIG. 4 but showing a structure for guiding the wind further left and right at the exhaust port of FIG. Although parts not directly related to the present invention are also described in FIGS. 1 to 5, the description thereof is omitted here. FIG. 6 is a plan view showing a two-lamp optical unit used in the present invention, and is a plan view modeling lamp exhaust and cooling means.
[0015]
As shown in FIG. 6, the layout of the two lamps according to the present invention is such that lamps A and B, in which the arc tube 40 is aligned and fixed in the vicinity of the first focal position of the elliptical reflecting mirror 41 and sealed by the front glass 42. Yes, the two-lamp combination is reflected 90 degrees on the left side of the figure by the two-lamp combination prism 35, is made almost parallel light by the collimator lens 5, enters each cell of the lens array A7, and is divided into a large number of minute light beams. It converges on each corresponding cell of B8. The lens array A7 and the lens array B8 may have the same shape.
[0016]
In the lens array B8, the light emitter images of the lamps 1 and 2 are formed on the left and right of each cell. Thereafter, the mirrors 28, the field lens 32, the liquid crystal panel 126, the combining prism 30, and the projection lens 31, which are color separation systems, are almost the same as the conventional projector optical system. In the model diagram of the lamp cooling means, the fans 50 and 51 are opposed to the left and right lamps, respectively, and heat generated from the lamps is guided to the projection lens side (front side of the main body) by the air passages 52 and 53. (As will be described later, in the embodiment, the ventilation passages 52 and 53 are formed on the back of the main base, and this is hereinafter referred to as front exhaust). The fans 50 and 51 are generally inexpensive axial flow type fans, which are the main body. It is contained in the case 14. Next, the configuration will be described in detail with reference to FIGS.
[0017]
As shown in FIG. 1, in the external appearance of the present embodiment, the projection lens side has left and right exhaust ports 56, 57 on the front surface of the lower case 54, and the upper case 55 is attached to the lower case 54 to form the appearance of the main body case. Further, as shown in FIG. 2, the left guide 58 and the right guide 59 are directed away from the projection lens in order to diffuse the wind to the left and right at the exhaust ports 56 and 57.
[0018]
Description of other components is omitted. In FIG. 3, the lower case 54, the upper case 55 and the optical unit are removed from FIG. 1, but the upper and lower cases and the optical unit and the fan are all attached to the main base 60 made of aluminum die casting. When the left and right lamp units 61 and 62 are shining, the heat source is guided to the lower side of the main base through the wind tubes 63 and 64 integrated with the main base 60 by the fan. 4 and 5 are views showing the main base from the lower side (opposite side). The heat flow guided by the fans 50 and 51 is guided to the front side of the main body by the ventilation passages 52 and 53, and the exhaust port. 56 and 57 are discharged to the outside.
[0019]
When the lower case and the upper case are tightened, this ventilation path is sealed, and heat is discharged without being accumulated inside the main body, so that the temperature rise of the main body can be suppressed. If the left guide 58 and the right guide 59 are further provided at the exhaust ports 56 and 57, the exhaust is further divided into left and right, so that it is possible to eliminate the hot flame phenomenon that easily occurs in front of the lens. Furthermore, if the exhaust port formed by the left guide 58 and the right guide 59 is brought to a position substantially the same as this lens, the main body can be mounted upside down and used in a stationary state. Since the exhaust air with high temperature flows upward, the hot flame phenomenon that occurs in front of the lens can be eliminated.
[0020]
【The invention's effect】
As described above, according to the present invention, the lamp cooling structure of the liquid crystal projector using two lamps has a constant ventilation path for the lamp exhaust heat, and the ventilation path from the heat source is separated from the optical component and the circuit board. In addition, by adopting a structure in which heat from the heat source is released from the fan to the exhaust port and efficiently exhausted to the outside, it is possible to provide a quiet liquid crystal projection device in which the fan rotation sound is difficult to hear.
[0021]
In addition, by tilting the louver forward and aligning the direction of the centrifugal fan, when using the main unit, it can be used without worrying about the noise coming out from the front to see from the side or rear of the main unit. Can be quiet. A liquid crystal projection apparatus having a cooling structure that smoothly exhausts heat from the heat source can be obtained.
[0022]
In addition, because the louver that determines the direction of the wind is tilted obliquely forward away from the projection lens, the left and right discharge ports are provided at approximately the same height as the projection lens, so the exhaust air is guided to the left and right and the heated wind rises As a result, air convection is less likely to occur in front of the projection lens, and fluctuations in the air in front of the lens (hot flame phenomenon) due to front exhaust can be eliminated.
[Brief description of the drawings]
FIG. 1 is a diagram showing a liquid crystal projection device in an embodiment of the present invention. FIG. 2 is a diagram showing a liquid crystal projection device provided with guides on the left and right in FIG. 1. FIG. FIG. 4 is a perspective view showing a base member, a cooling means, a ventilation path, and an exhaust port when FIG. 3 is viewed from the back side. FIG. 5 is a structure for guiding wind to the left and right in FIG. FIG. 6 is a plan view showing a two-lamp optical unit, and is a plan view modeling a lamp exhaust and cooling means. FIG. 7 is a plan view showing a conventional two-lamp optical layout. FIG. 9 is a plan view showing a cooling structure of the main body using the two-lamp optical system proposed by the authors. FIG. 10 is a two-lamp optical layout conventionally proposed by the authors. FIG. 11 is a plan view showing Plan view showing one-lamp optical layout
1, 2 Lamp 7 First lens array 8 Second lens array 28 Mirrors 50, 51 Fan 52, 53 Ventilation path 54 Lower case 55 Upper case 56, 57 Exhaust port 58 Left guide 59 Right guide 60 Main base 61, 62 Lamp unit

Claims (3)

Two lamps each having an arc tube fixed in the vicinity of the focal position of a reflecting mirror having a concave reflecting surface, two cooling means for suppressing the temperature rise of the lamp and the temperature inside the main body, and light from the plurality of lamps Reflecting means for reflecting in a predetermined direction, collimating means for making the light substantially parallel light by the reflecting means, color separating means for separating the two lamps into red, blue and green, and modulating each of the red, blue and green light A liquid crystal panel; a combining optical unit that combines the modulated light to the liquid crystal panel; a projection lens that projects the combined light; the lamp; the cooling unit; the collimating unit; the liquid crystal panel; An optical case for holding the combining optical means, the projection lens, etc., and holding the optical case at the upper part, and guiding each hot air from the two lamps to the lower part by the cooling means. A liquid crystal projection comprising a base member provided with two air paths independently flowing along two predetermined guide grooves on the projection lens side, a main body case containing the optical case, the cooling means, and the base member apparatus. The air passage for exhausting air from the discharge port of the cooling means to the outside of the main body case and the louvers for determining the wind direction are provided on the left and right in the same direction as the projection lens, and the louvers are inclined obliquely forward and away from the projection lens. The liquid crystal projection apparatus according to claim 1. The liquid crystal projection apparatus according to claim 1, wherein the left and right discharge ports are provided at substantially the same height as the projection lens.

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