ELECTRONIC DEVICE AND PROJECTORS

An electronic device includes an illumination optical system for outputting light to the projection lens, a blower for cooling a liquid crystal panel mounted on the illumination optical system, a first duct for guiding the air blown out from the blower to the liquid crystal panel, a second duct for guiding the air passing through the liquid crystal panel in the direction opposite to the direction of the air blown out from the blower and a heat sink for removing heat from the air passing through the second duct, and a holding member for holding the blower and guiding the air from which heat has been removed by the heat sink to the air inlet of the blower is provided in a dust-proof case

TECHNICAL FIELD

The present invention relates to electronic device and projectors.

BACKGROUND ART

Main modules constituting a projection type display device for projecting an image include light sources such as lamps, lasers, and LEDs (Light Emitting Diode), illumination optical systems, projection lenses, electronic substrates, and power supplies. Optical electronic components for generating images using an optical modulator such as DMD (Digital Mirror Device) or a liquid crystal panel is mounted on the illumination optical system. In response to an external video signal, an electronic substrate generates a drive signal for driving the optical modulator. Strong light is sent from the light source of the lamp or laser/LED to the illumination optical system and irradiates the light modulator through each optical component. The projection lens enlarges the light emitted from the light modulator and projects it on the screen.

In these processes, the electronic component generates heat due to electrical resistance, the optical component temperature rise due to the absorption of light is generated. Each component must be operated so as not to exceed the allowable temperature to achieve the desired performance. Therefore, a plurality of cooling fans are mounted in the device, the blower from the cooling fan cools each component, to prevent a temperature increase so as not to exceed the allowable temperature. Further, since the life time of the liquid crystal panel is determined according to the temperature, it is necessary to further reduce the temperature.

For example, a pair of fans are respectively arranged on both sides of the projection lens, an apparatus for performing cooling is considered (e.g., see Patent Document 1.).

In the cooling of the display device, it is necessary to prevent the dust from entering the device from the outside together with the cooling air and adhering to the optical components, etc. to cause luminance deterioration. Therefore, generally the optical component is surrounded by a box, the mating portion of the box is sealed with a packing such as a soft metal such as cushion or rubber or copper, and has a structure to prevent the inflow of dust. Strong light is sent into the enclosed box.

PRIOR ART DOCUMENTS

Patent Document

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

In the sealed structure as described above, when attempting to cool the illumination optical system, the gap between the cooling duct and the illumination optical system from the blower to the illumination optical system, and sealing of the gap between the circulation duct and the illumination optical system is required, and the closed structure is needed for all circulation paths. Thus, if the sealing with many sealing portions complicated shapes, increasing the dust entry point causes a deterioration in performance, also, there is a problem that the size of the illumination optical system including the cooling structure is increased.

An object of the present invention is to provide an electronic device and a projector to solve the problems described above.

A Means for Solving the Problem

The electronic device of the present invention,

an illumination optical system that outputs light to a projection lens,

blowers that cool liquid crystal panels mounted on the illumination optical system,

a first duct that guides the air blown out from the blowers to the liquid crystal panels,

a second duct that guides the air passing through the liquid crystal panel in the direction opposite to the direction of the air blown out from the blowers,

a heat sink that removes heat from the air that has passed through the second duct; and

a blower holding member that holds the blowers and guides the air from which head has been removed by the heat sink to the air inlet of the blowers, wherein

the illumination optical system, the plurality of blowers, the first duct, the second duct, the heat sink and the blower holding member are provided in a dust-proof case.

Further, the projector of the present invention,

an illumination optical system that outputs light to a projection lens,

blowers that cool liquid crystal panels mounted on the illumination optical system,

a first duct that guides the air blown out from the blowers to the liquid crystal panels,

a second duct that guides the air passing through the liquid crystal panel in the direction opposite to the direction of the air blown out from the blowers,

a heat sink that removes heat from the air that has passed through the second duct; and

a blower holding member that holds the blowers and guides the air from which head has been removed by the heat sink to the air inlet of the blowers, wherein

the illumination optical system, the plurality of blowers, the first duct, the second duct, the heat sink and the blower holding member are provided in a dust-proof case,

light source, wherein

the electronic device receives the light from the light source and modulates the incident light.

Effect of the Invention

As described above, in the present invention, it is possible to perform efficient cooling in a sealed structure.

EXEMPLARY EMBODIMENT

This will be described below with reference to the accompanying drawings embodiments of the present invention.

First Embodiment

FIG. 1is a diagram illustrating a first embodiment of the electronic device of the present invention. Electronic device100in this embodiment, as shown inFIG. 1, illumination optical system101, liquid crystal panel102, blower103, first duct104, second duct105, heat sink106, and blower holding unit107. Illumination optical system101projects the light. Blower103cools liquid crystal panel102mounted on illumination optical system101. First duct104guides the air blown from blower103to liquid crystal panel102. Second duct105guides the air passing through liquid crystal panel102in the opposite direction to the direction of the air blown out from blower103. Heat sink106removes heat the air passing through second duct105. Blower holding unit107is a blower holding member holds blower103, and guides the air which is removed heat by heat sink106to the air inlet of blower103. Each of these components is housed in dust-proof case108having a sealed structure.

Thus, in dust-proof case108, the air blown out from blower103for cooling liquid crystal panel102is guided to heat sink106using a first duct and a second duct, the air removed heat by heat sink106is circulated to the air inlet of blower103. Thus, it is possible to perform efficient cooling in a sealed structure.

Second Embodiment

FIG. 2is a diagram illustrating a second embodiment of the electronic device of the present invention. Projector111, which is an electronic device in this embodiment, as shown inFIG. 2, has illumination optical system112and light source unit113.

Illumination optical system112for outputting light to projection lens121has a XDP122which is a cross dichroic prism, three liquid crystal panels123-125, mirror126, field lens127, mirror128, relay lens129, mirror130, relay lens131, color filter132, field lens133, color filter134, field lens135, PBS (Polarizing Beam Splitter)136which is a polarizing beam splitter, and integrator137for adjusting the uniformity of illuminance. Light source unit113includes lens138, DM139, lens140, phosphor141, lens142, lens143, and laser144. Each component of illumination optical system112and light source unit113is identical to that of a typical projector.

Light from laser144is output using other components constituting light source unit113. Also, in this embodiment, of the light that passed through integrator137, PBS136and field lens135, blue light is reflected by color filter134, passes through field lens127and is reflected by mirror126. Also, of the light that has passed through integrator137, PBS136and field lens135, green light passes through color filter134and field lens133and is reflected color filter132. Also, of the light that has passed through integrator137, PBS136and field lens135, red light passes through color filter134, field lens133, color filter132and relay lens131, is reflected by mirror130, passes through relay lens129and is reflected by mirror128. Therefore, liquid crystal panel123modulates the blue light. Further, liquid crystal panel124modulates the green light. Further, liquid crystal panel125modulates the red light.

In the arrangement of such a 3LCD, the planar shape of illumination optical system112is a rectangle in the direction in which liquid crystal panel123and liquid crystal panel125face the long side.

Fans203to205, which are blowers, are provided to cool liquid crystal panels123-125, respectively. Fans203to205are arranged side by side along a first direction in which liquid crystal panel123and liquid crystal panel125of liquid crystal panels123to125face each other on a side opposite to the side in which projection lens121of liquid crystal panels123to125is disposed. Incidentally, when the components constituting illumination optical system112are housed in one rectangular parallelepiped that can store their layout (broken line of illumination optical system112shown inFIG. 2) or a housing having a shape corresponding thereto, fans203to205are disposed on the surface side facing the surface on which projection lens121of the housing is disposed. In that case, fans203to205may be disposed within the housing or may be disposed outside the housing.

Further, heat sink211is disposed on a side of fans203to205opposite to the side of illumination optical system112. Heat sink211removes heat from the intake air drawn in by fans203-205. Illumination optical system112, fans203-205, and heat sink211are housed in dust-proof case150that maintains a sealed state. Furthermore, heat sink211is connected to heat sink212,213for heat radiation provided on the outside of dust-proof case150. Heat sink211and heat sink212,213for heat radiation are connected via heat pipe214which passes through the two surfaces of dust-proof case150facing each in a direction perpendicular to the direction of the air blown out from fan203to205. It is needless to say that the sealing is made in that portion on the surface of dust-proof case150which heat pipe214penetrates. By this connection, the heat that heat sink211is absorbed (removals heat) is transferred to heat sink212,213through heat pipe214, and the heat that is transferred to heat sink212,213is released to the outside.

InFIG. 2, a cooling duct for guiding the air blown out from fans203to205to liquid crystal panels123to125, respectively, and a high-temperature air duct for guiding the air passing through liquid crystal panels123to125to heat sink211are not shown. These will be described with reference toFIG. 7to be described later.

FIG. 3is a diagram illustrating an example of the appearance of projector111in this embodiment. As shown inFIG. 3, dust-proof case150is provided inside projector111. Illumination optical system112, fans203to205, and heat sink211are housed in dust-proof case150. Further, dust-proof case150has a structure in which the upper housing and the lower housing are coupled so as to sandwich projection lens121. Further, the coupling portion between the upper housing and the lower housing is coupled using packing at the flat portion, and using cushion material at the convex portion and the concave portion.

FIG. 4is a diagram illustrating an example of the appearance of fan203shown inFIG. 2.FIG. 5is a plan view of fan203shown inFIG. 4viewed from the direction of A. Incidentally, the same applies to fan204,205shown inFIG. 2. As shown inFIGS. 4 and 5, fan203in this embodiment is a blower fan that performs air intake from the side surface of fan203, blowing in a direction perpendicular to the intake direction. That is, fan203is a blower fan in which the direction of the air intake and the direction of the blowing are perpendicular, characterized by a high static pressure. Incidentally, in the example shown inFIG. 5, as an example in which air intake is performed from both sides of fan203, air intake may be performed from only one side.

Incidentally, the rotation of fans203to205is individually controlled, and the rotational speed may be different from each other. This rotational speed may be set in advance based on the operation of the light modulation in liquid crystal panels123to125, may be one that measures the temperature of liquid crystal panels123to125and is controlled based on the measured temperature, or may be one that is controlled based on the use period of liquid crystal panels123to125.

FIG. 6is a plan view illustrating an example of a configuration of a cooling duct for guiding the cooling air blown out from fans203to205shown inFIG. 2to liquid crystal panels123to125. As shown inFIG. 6, the cooling air blown out from fans203to205that suck the air from which heat has been removed by heat sink211passes through the respective spaces provided in cooling duct304and is guided to LCD cooling openings301to303for cooling liquid crystal panels123to125, respectively. InFIG. 6, a high-temperature air duct for guiding the air passing through liquid crystal panels123to125to heat sink211is not shown.

Incidentally, fans203to205are arranged at intervals at which a predetermined intake amount can be secured. Further, a partition plate may be provided between each of fans203to205. Further, when fans203to205perform air intake from both sides, the position of the partition plate may be determined based on the ratio of the air intake capacity from one side to the air intake capacity from the other side. Specifically, for example, when the air intake capacity from the left side surface of fans203to205is larger than the air intake capacity from the right side surface, the distance from the left side surface of fans203to205to the partition plate on the left side may be longer than the distance from the right side surface of fans203to205to the partition plate on the right side.

Also, the positions of the respective air outlets of fans203to205with respect to cooling ducts304, i.e., the distances from the air outlets of fans203to205to the receptacles of cooling ducts304, are preferably equal to each other.

Further, as shown inFIG. 6, since liquid crystal panels123to125are arranged as shown inFIG. 2, LCD cooling openings301to303for cooling liquid crystal panels123to125, respectively, are arranged at different distances from each other from fans203to205, as shown inFIG. 6. That is, as shown inFIG. 6, among fans203to205, the distance from the air outlet of fan204disposed in the center to LCD cooling opening302(liquid crystal panel124) is shorter than the distance from the air outlet of fan203,205to LCD cooling opening301,303(liquid crystal panel123,125) respectively.

FIG. 7is a side view of fan204, cooling duct304and illumination optical system112shown inFIG. 6, viewed from the side direction of projector111. As shown inFIG. 7, cooling duct304is disposed at the bottom of illumination optical system112. Cooling air blown out from fan204cools liquid crystal panel124from LCD cooling opening302through cooling duct304. High-temperature air duct305, that is a second duct, guides the air that passed through liquid crystal panel124, to heat sink211in the direction opposite to the direction of the air blown out from fan204. Heat sink211removes heat from the air that has passed through high-temperature air duct305. Blower holding unit306is a blower holding member houses and holds fan203, and guides the air from which heat has been removed by heat sink211to the air inlet of fan203. Here, high-temperature air duct305is a space surrounded by dust-proof case150and illumination optical system112and blower holding unit306is formed along the top surface of dust-proof case150. Illumination optical system112, cooling duct304, fan204, blower holding unit306and heat sink211are housed in dust-proof case150. Further, heat sink211may be held by blower holding unit306. The height h3of fan204may be of the same height as the height h4of heat sink211.

Further, the height h5from the bottom surface of dust-proof case150to the top surface of illumination optical system112is preferably made to be the same height as the height h6from the bottom surface of dust-proof case150to the top surface of blower holding unit306. Thus, it is possible to sufficiently secure the flow path (height) of high-temperature air duct305, to realize a miniaturization of the circulation cooling system. Further, since the bottom surface of high-temperature air duct305is composed of a top surface of optical engine112and the top surface of blower holding unit306, so the height h5is the same as the height h6, the bottom surface of high-temperature air duct305becomes a flat surface, it is possible to minimize the loss of the flow of high-temperature air.

FIG. 8is a diagram of the arrangement of fans203to205shown inFIG. 2viewed from the side of the illumination optical system112. As shown inFIG. 8, it is preferable that fans203to205have the same height h1of the air outlet. Fans203-205may also have their own heights h2identical to each other.

FIGS. 9 to 11are diagrams illustrating an example of the structure of cooling duct304shown inFIG. 6.FIG. 9is a perspective view of cooling duct304before assembling the upper housing and the lower housing.FIG. 10is a plan view of cooling duct304before assembling the upper housing and the lower housing.FIG. 11is a perspective view of cooling duct304after assembling the upper housing and the lower housing. The upper housing and the lower housing shown inFIG. 9is assembled by fitting the portion of the claw in accordance with a broken line. As shown inFIGS. 9 to 11, in cooling duct304, a space through which the cooling air blown out from each of fans203to205passes is provided separately.

FIG. 12is a diagram illustrating an example of a positional relationship between the fan and the heat sink provided in projector111shown inFIG. 2. As shown inFIG. 12, projector111shown inFIG. 2includes fans215to217outside dust-proof case150in addition to fans203to205provided inside dust-proof case150. Fan215is for cooling heat sink212for heat dissipation and blows cooling air to heat sink212for heat dissipation. Fan216is for cooling heat sink213for heat dissipation and dissipates heat generated from heat sink213for heat dissipation. Fan217is for cooling light source unit113and takes heat generated from light source unit113.

Thus, projector111in this embodiment, in the optical illumination system of 3LCD in which the optical axis direction passing through the integrator and the PBS and the projection direction of the projected image are arranged vertically, a plurality of fans for cooling the three LCDs (liquid crystal panels) respectively comprises a sealed structure having a configuration arranged along the long side of illumination optical system112. Projector111features a compact circulation cooling configuration that circulates air in dust-proof case150with a sealed structure. In projector111, illumination optical system112, fans203-205for cooling liquid crystal panels123-125are provided in the illumination optical system, cooling duct304and heat sink211are disposed in dust-proof case150of the sealed structure. In projector111, cooling duct304is disposed at a bottom portion of illumination optical system112, fans203to205are disposed on a side opposite to the side where projection lens121of illumination optical system112is disposed, and heat sink211is disposed behind fans203to205. Further, in projector111, an illumination optical system to integrator137is disposed in dust-proof case150.

Further, projector111in the present embodiment blows the air blown out from fans203to205through cooling duct304, cools liquid crystal panels123to125and the peripheral optical components, and the air that is blown through high-temperature air duct305formed in dust-proof case150, has heat removed from it in heat sink211and is sucked into fans203to205. At this time, a partition is provided so that the air from which heat has been removed does not mix with liquid crystal panels123to125and the high-temperature air after cooling the peripheral optical components. For example, as shown inFIG. 7, blower holding unit306may cover other than the surface that is in contact with the high-temperature air of heat sink211. Further, a partition is provided in which the intake air of fans203to205in blower holding unit306and the air after heat removal flowing through cooling duct304are not mixed. For example, a partition may be provided to fill the gap between fans203to205and blower holding unit306. As regards dust-proof case150, it is necessary to seal using a packing or the like so that dust does not enter, since the partition of cooling duct304and blower holding unit306is in the dust-proof structure, sealing such as packing is not necessary.

Further, since entire dust-proof case150is a part of the duct, high-temperature air duct305formed by the bottom surface and the top surface and blower holding unit306in dust-proof case150can be miniaturized without overlapping partitions. Further, blower holding unit306has a function of holding fans203to205and a function of insulating the high-temperature air passing through high-temperature air duct305after cooling of liquid crystal panels123to125with the air removed through heat sink211. Further, in the optical illumination system of 3LCD in which the optical axis direction through which the integrator and the PBS pass and the projection direction of the projected image are vertically disposed, fans203to205for cooling the three LCDs (liquid crystal panels) respectively are disposed along the long sides of illumination optical system112, so that a large intake area of fans203to205can be secured, the loss of the intake air is small, the length of the flow passage is short, and the pressure loss is small. Further, the width of cooling duct304can also be secured widely, respectively, and the loss is small. Therefore, because both the intake air efficiency and the cooling duct efficiency are increased, cooling efficiency is improved.

Furthermore, heat sink212,213for heat dissipation on both sides of dust-proof case150are provided. Thus, heat sink211for heat receiving provided in dust-proof case150, performs heat removal of high-temperature air, heat is transferred to heat sink212,213through heat pipe214, heat sink212,213is cooled and heat is discharged outside the device. Heat sink211is connected to heat sink212,213at both ends via heat pipe214, and is also thermally connected. Heat sink212,213, by being connected to both ends of heat sink211, since heat that heat sink211is received is transferred to both sides, the same effect as when the number of pipes doubled is obtained. Since the heat has a property of being transmitted from the higher to the lower, efficiency is lowered when the point is at a temperature lower than the temperature of the point where the high temperature due to the specks of temperature in heat sink211is upstream. By heat sink212,213is connected to both sides of heat sink211, it is possible to prevent a decrease in efficiency caused by specks of temperature.

Further, by providing the parts to integrator137in dust-proof case150, it is possible to cool the parts requiring cooling such as PBS in the same cooling flow and to reduce the number of parts. Further, the alignment of light source unit113and illumination optical system112are facilitated, it is possible to improve the dust-proof performance structural, and the number of components are reduced.

Further, the cooling air blown out from the cooling fan for LCD cools the optical components such as LCD through the cooling duct. Generally, the cooling duct and fan holder are made of an expensive material with vibration isolation to reduce wind noise generated at that time. Cooling fans for LCDs have a great effect on noise values. In this embodiment, fan203to205, cooling duct304, and blower holding unit306are disposed in dust-proof case150, and dust-proof case150shields the noise, thereby reducing the noise value. Further, because dust-proof case150shields the noise, it is possible to adopt an inexpensive material as cooling duct304and blower holding unit306and to reduce component cost.

As described above, the life cycle of liquid crystal panels123to125is extended by increasing the cooling efficiency, and the rotational speed of fans203to205can also be lowered, which makes it possible to reduce the annoying noise value. The structure becomes simple due to blower holding unit306and dust-proof case150having the two roles described above and it is possible to reduce the size of the entire apparatus. Further, by performing the sealing of dust-proof case150, it is not necessary to seal the internal parts. Therefore, by reducing the number of parts, it is possible to realize a reduction in the cost of all components that are used. In addition, manufacturing costs can also be reduced.