JP5082981B2 - projector - Google Patents

Description

  The present invention relates to a projector provided with a heat generating component, and more particularly to measures against heat of the projector.

  2. Description of the Related Art Conventionally, a projector as a projection display device that enlarges and projects an image of a video source onto a screen via an optical system is known as one of display devices in an electronic apparatus.

  Since the projector has a heat generating component such as a light source, if the heat of the heat generating component is transmitted to the optical member on the optical path, the mounting accuracy and thermal characteristics of the optical member may be affected and the optical characteristics may be deteriorated. There is.

As a technique related to the heat countermeasure of the projector, for example, there is a technique in which a heat radiating body such as a heat sink is attached to a reflective liquid crystal panel which is a light modulation means to dissipate heat (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 14-098937

  As a heat generating component of the projector, there are a light source, a power supply unit, and the like in addition to the light modulation means. Generally, these heat generation amounts are larger than those of the light modulation means. The temperature difference between multiple heat-generating components may cause thermal expansion of the optical member and non-uniformity in the mounting accuracy of the optical member, resulting in distortion of the optical path and changes in the characteristics of the optical system, leading to deterioration of the projected image. There is.

  In recent years, there has been a trend toward miniaturization of projectors, and accordingly, thermal countermeasures for projectors have become more important.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a projector capable of suppressing a temperature difference between a plurality of heat generating components.
Another object of the present invention is to provide a projector suitable for miniaturization.

In order to achieve the above object, a projector according to the present invention includes a plurality of heat generating components, a heat radiating member, and a heat transfer member that thermally connects the plurality of heat generating components and the heat radiating member. The heat generating component is characterized in that a thermal distance on the heat transfer member to the heat dissipating member is short in descending order of heat generation amount.
That is, in the projector of the present invention, the heat generating component having a large heat generation amount has a short thermal distance on the heat transfer member to the heat dissipating member, and the heat generating component having a small heat generation amount is on the heat transfer member to the heat dissipating member. The thermal distance of is long.
The “thermal distance” is a distance of heat transfer between the heat-generating component and the heat radiating body, and can be measured along the heat flow direction on the heat transfer member.

Here, FIG. 1 is a figure for demonstrating the thermal resistance of a heat-transfer member.
The thermal conductivity of the heat transfer member is λ (W / (m ° C.)), the temperature difference between both sides of the heat transfer member (temperature difference in the direction of heat flow) is ΔT (° C.), and the heat transfer area of the heat transfer member is A ( m ² ) When the length of the heat transfer member (the distance measured along the heat flow direction) is L (m), the amount of heat Q (W) passing through the heat transfer member is expressed by the following equation (1). .
Q = λ × A × ΔT / L (1)
The thermal resistance R when the heat transfer member passes 1 W of heat is expressed by the following equation (2).
R = ΔT / Q = L / (λ × A) (2)

  That is, the thermal resistance of the heat transfer member changes in proportion to the length (thermal distance) from the heat generating component to the heat radiating body. That is, the longer the thermal distance, the greater the thermal resistance, and the shorter, the smaller the thermal resistance.

In the projector according to the present invention, since the thermal distance from the heat generating component to the radiator is short in descending order of the heat generation amount of the plurality of heat generating components, the heat generating component having a large heat generation amount has a small thermal resistance when radiating heat and Small heat-generating parts have a large thermal resistance during heat dissipation. Therefore, more heat is radiated from the heat-generating component having a large heat generation amount, and heat radiation from the heat-generating component having a smaller heat generation amount is suppressed. Therefore, the temperature difference between the plurality of heat generating components is suppressed.
Further, since the thermal distance on the heat transfer member (the length of the heat transfer member) is determined based on the heat generation amount of each heat generating component, the shape of the heat transfer member is optimized, and as a result, It becomes possible to keep the volume of the heat transfer member small.
For these reasons, in the projector according to the present invention, it is possible to suppress a temperature difference among a plurality of heat generating components and to reduce the size of the apparatus.

In the projector described above, examples of the plurality of heat generating components include a light source, a power supply circuit, and a light modulation unit (light valve).
In this case, since the light source is an LED light source including a light emitting diode (LED), it is easier to reduce the size of the apparatus.

In the projector, the plurality of heat generating components may be arranged on one side of the heat radiating body, and the heat radiating member may have a larger surface area as it is closer to the plurality of heat generating components.
That is, in this case, in the heat radiating body, the surface area is larger as it is closer to the plurality of heat generating components, and the surface area is smaller as it is farther away.
According to this configuration, since the surface area of the heat dissipator close to the heat-generating component is formed large, the heat dissipating efficiency can be improved, and the heat dissipator volume can be kept small.

In the projector described above, when the heat radiator has a plurality of fins, the plurality of fins are preferably arranged such that gaps between the plurality of fins extend in a vertical direction.
According to this configuration, since the gap between the plurality of fins extends in the vertical direction, the air that is warmed by the radiator is likely to rise. Is planned.

In the projector described above, the heat emissivity of the radiator is preferably 0.5 or more.
When the thermal emissivity (steaming rate) of the radiator is 0.5 or more, heat is radiated well from the radiator into the air, and the heat dissipation efficiency of the radiator is improved.

The projector may include a housing that covers the plurality of heat generating components, and the plurality of heat generating components and the housing may be thermally connected.
According to this configuration, the heat of the plurality of heat generating components is also radiated from the housing. Therefore, the thermal load on the radiator is reduced, the volume of the radiator can be reduced, and the apparatus can be miniaturized.

In this case, the housing has a plurality of side surfaces arranged in the horizontal direction and an upper bottom surface arranged in the vertical direction, and the upper surface is larger than a total surface area of the plurality of side surfaces. It is preferable that the total surface area of the bottom surface exceeds twice.
In general, the surface arranged upward in the vertical direction has higher heat radiation efficiency (about twice) than the surface arranged in the horizontal direction because warmed air is easily separated from the surface.
According to said structure, since the area of the upper surface with high heat dissipation efficiency becomes large enough, the heat dissipation efficiency from a housing | casing is high.

Moreover, it is preferable that the heat absorption rate of the inner surface of the housing is 0.5 or more.
When the heat absorption rate of the inner surface of the housing is 0.5 or more, the heat inside the housing is well absorbed by the housing, and the heat is dissipated outside the housing. Therefore, the temperature rise inside the housing is suppressed, and the thermal load on the radiator is reduced.

The thermal emissivity of the outer surface of the housing is preferably 0.5 or more.
When the thermal emissivity of the outer surface of the housing is 0.5 or more, heat is radiated well from the housing to the outside air, and the heat dissipation efficiency from the housing is increased.

Moreover, it is preferable that the housing is provided with an intake hole and an exhaust hole disposed above the intake hole.
According to this configuration, due to the convective heat transfer of air, the air flowing in from the intake hole passes through the inside of the casing and takes the heat of the heat generating component, and the air is discharged from the exhaust hole. At this time, since the exhaust holes are arranged above the intake holes, the air easily flows through the housing, for example, warmed air is likely to rise. Therefore, heat exchange is effectively performed between the air and the heat generating component. Thereby, in this structure, the temperature rise of a several heat-emitting component is suppressed and degradation of a projection image is suppressed.

The exhaust hole is preferably provided on the upper surface of the housing.
According to this configuration, the exhaust hole is provided on the upper surface of the casing, so that the air in the casing is surely discharged from the exhaust hole even when the projector is arranged obliquely during use.
Note that the upper surface of the casing refers to a surface arranged upward in the vertical direction when the projector is used. When the surface of the case that is placed upwards in the vertical direction may change depending on the usage method, such as when the projector is turned upside down between desktop installation (floor installation) and hanging installation (ceiling installation) In addition, it is preferable to provide exhaust holes on all the surfaces that may be arranged upward during use.

The opening area of the exhaust hole is preferably larger than the opening area of the intake hole.
According to this configuration, air is easily discharged from the housing including the thermal expansion of air, and heat exchange is effectively performed between the air and the heat-generating component.

The plurality of heat generating components are preferably arranged between the intake hole and the exhaust hole in the vertical direction.
According to this configuration, since the plurality of heat generating components are arranged in the middle of the air flow from the intake hole to the exhaust hole, heat exchange is effectively performed between the air and the heat generating component.

Further, it is preferable that the air passage through which the air passes is bent in the intake hole and the exhaust hole.
According to this configuration, since the flow paths of the intake holes and the exhaust holes are bent, entry of foreign matter into the inside of the housing is prevented.

In addition, the projector of the present invention includes a heat generating component, a heat radiating member, and a heat transfer member that thermally connects the heat generating component and the heat radiating member, and the heat radiating member has a surface area closer to the heat generating component. It is characterized by being formed large.
According to this projector, since the surface area of the heat dissipator close to the heat-generating component is formed, the heat dissipating efficiency can be improved, and the heat dissipator volume can be kept small. Therefore, the apparatus can be reduced in size.

[First Embodiment]
An embodiment of a projector according to the present invention will be described below with reference to the drawings.
Here, as a first embodiment, three liquid crystal devices (in this example) corresponding to three colors R (red), G (green), and B (blue) are used as spatial light modulation means (light valves). A three-plate reflective liquid crystal projector provided with a reflective liquid crystal panel will be described.
The present invention can also be applied to a one-plate liquid crystal projector or a projector using another spatial light modulation device (for example, DMD; Digital Mirror Device) as a light valve.

FIG. 2 is a diagram schematically showing a schematic overall configuration of the liquid crystal projector 10.
In FIG. 2, a projector 10 includes a light source (lamp) 11, a condensing lens 12, dichroic mirrors 13 and 14, a reflecting mirror 15, a relay lens 16, beam splitters 17, 18, and 19, liquid crystal light valves 20, 21, 22, It includes a cross dichroic prism 23, a projection system 24, and the like. Here, among the three light valves 20, 21, 22, the light valve 20 corresponds to light of R (red), 21 corresponds to light of G (green), and 22 corresponds to light of B (blue).

  In this example, a halogen lamp is used as the light source 11. In addition, a high pressure mercury lamp, a metal halide lamp, or the like may be used as the light source. The light from the light source 11 is collected by the condenser lens 12 and enters the dichroic mirror 13.

  The dichroic mirror 13 transmits red light (R) out of light from the light source 11 and reflects green light (G) and blue light (B). The dichroic mirror 14 transmits blue light (B) and reflects green light (G) among the reflected light of the dichroic mirror 13.

  The red light (R) that has passed through the dichroic mirror 13 is reflected by the reflecting mirror 15 and enters the light valve 20 via the relay lens 16 and the beam splitter 17. On the other hand, of the light reflected by the dichroic mirror 13, green light (G) is reflected by the dichroic mirror 14 and enters the light valve 21 through the beam splitter 18. The blue light (B) passes through the dichroic mirror 14 and enters the light valve 22 via the beam splitter 19.

  The light valves 20, 21 and 22 include, for example, a thin film transistor (TFT) as a switching element and a reflective liquid crystal cell, and are supplied from the light source 11 based on image information (or video information) from the outside. Modulate light. The light reflected by the light valves 20, 21, 22 enters the cross dichroic prism 23 through the beam splitters 17, 18, 19, respectively.

  The prism 23 has a structure in which four right-angle prisms are bonded together, and the whole is formed in a substantially cubic shape. The prism 23 includes a dielectric multilayer film 23a that reflects red light (R) and a dielectric multilayer film 23b that reflects blue light (B), and transmits green light (G) from the light valve 21. The red light (R) from the light valve 20 and the blue light (B) from the light valve 22 are bent to combine these three colors of light to form a color image.

  The projection system 24 includes an enlarged projection optical system, and projects the light emitted from the prism 23 onto a screen (not shown). By this projection, an enlarged color image is displayed on the screen.

FIG. 3 is a plan view schematically showing the state of the arrangement of the constituent members in the projector 10.
In FIG. 3, the above-described constituent members are mounted on a base plate 30. The base plate 30 is also equipped with a power supply circuit 31 and a light valve drive circuit (liquid crystal drive circuit). The liquid crystal driving circuit is mounted on the surface of the base plate 30 opposite to the mounting surface of other components, and is not shown.

  The power supply circuit 31 includes a transistor 31 a (FET transistor), and the transistor 31 a generates the largest amount of heat in the power supply circuit 31. Similarly, the light source 11 (lamp) and the light valves 20, 21, and 22 generate a relatively large amount of heat when the projector 10 is used.

  The projector 10 of this example thermally connects the heat generating component 32 and the heat sink 32 as a heat radiator that radiates heat from these heat generating components (the light source 11, the light valves 20, 21, 22, and the transistor 31a). And a heat transfer member 33.

  As the heat sink 32, for example, one having a plurality of plate-like fins is used. Note that the heat sink is not limited to a form having a plurality of plate-like fins, but may have another form. Moreover, it may replace with a heat sink and you may use another thermal radiation means (for example, cooling fin). Since the heat sink does not have a drive mechanism, there is an advantage that it is easy to reduce the size.

  As the heat transfer member 33, a good heat conductor is preferably used. For example, in addition to an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof, copper, brass, gold, iron (and steel), Various metals such as nickel and alloys thereof are used.

Here, the heat generation amount of each heat generating component is light source 11: 50W, red light valve 20: 1W, green light valve 21: 2W, blue light valve 22: 3W, and transistor 31a: 69W.
The plurality of heat generating components (light source 11, light valves 20, 21, 22, and transistor 31a) have a thermal distance on the heat transfer member 33 to the heat sink 32 in descending order of the heat generation amount. It is getting shorter.

  That is, among the plurality of heat generating components, the heat generation amount of the transistor 31a (62W) and the heat generation amount of the light source 11 (50W) are particularly large, and the heat generation amount between them is as follows: transistor 31a> light source 11. Yes. Therefore, the thermal distance to the heat sink 32 is light source 11> transistor 31a.

  Of the plurality of heat generating components, the light valves 20, 21, and 22 generate a smaller amount of heat than the other heat generating components (light source 11, transistor 31a), and the blue light valve 22 (B) generates heat. Amount> heat generation amount (G) of the green light valve 21> heat generation amount (R) of the red light valve 20 (B> G> R). Therefore, the light bulbs 20, 21, and 22 have a longer thermal distance to the heat sink 32 than the light source 11 and the transistor 31a, and the thermal distance is such that the red light bulb 20 (R)> green. Light valve 21 (G)> Blue light valve 22 (B) (R> G> B).

  With this configuration, in the projector 10 of this example, more heat is radiated from the heat generating components (light source 11 and transistor 31a) having a larger heat generation amount, and the heat generating components (light valves 20, 21, 22) having a smaller heat generation amount than that. ) Is suppressed. Therefore, the temperature difference between the plurality of heat generating components is suppressed.

  Further, in the projector 10 of this example, since the thermal distance (the length of the heat transfer member 33) on the heat transfer member 33 is determined based on the heat generation amount of each heat generating component, the shape of the heat transfer member 33 is determined. As a result, the volume of the heat transfer member 33 can be kept small. Therefore, the projector 10 can be downsized.

Example 1
Next, the effect of the heat countermeasure technique was examined for the projector 10 of the first embodiment shown in FIG. 3 (Example 1, Comparative Example 1).
Here, a forward converter type switching regulator circuit (input: commercial power supply 100V, output: DC12V × 12A) was used as the power supply circuit. The FET transistor in the power circuit generated the most heat, and the amount of heat generated was 62W.
The lamp (light source) is a halogen lamp 12V-50W (USHIO JCR12V-50WG / 32) and the heat sink is Alpha UB60-25B (thermal resistance 1.3 ° C / W when air volume is 0.5m / sec) ) Was used.

The design of the heat transfer member that thermally connects the transistor and heat sink, the lamp and heat sink, the reflective liquid crystal panel (light valve) and the heat sink in the power supply circuit will be described below.
In the following description, the unit of dimensions in the drawings is “mm”.

The heat value of the transistor is 62 W, the heat value of the halogen lamp is 50 W, and the heat value of the reflective liquid crystal panel is 3 W for blue (B), 2 W for green (G), and 1 W for red (R).
Therefore, the heat sink dissipates 118W. Therefore, the temperature difference between the heat sink and the atmosphere is
118 (W) x 1.3 (° C / W) / 6 = 25.6 (° C) (3)
It becomes.

The operation compensation upper limit environmental temperature of this projector is 35 ° C. The component with the lowest upper limit temperature is a reflective liquid crystal panel, and its temperature is 65 ° C.
Therefore, the allowable temperature difference generated at both ends of the heat transfer member is expressed by the following equation (4) from equation (3).
ΔT = 65−25.6−35 = 4.4 (℃)… (4)

(Heat transfer member E: Red reflective liquid crystal panel to heat sink)
From FIG. 3, the longest distance between the red reflective liquid crystal panel and the end of the heat sink is expressed by the following equation (5).
L = 0.093 + 0.196 + 0.36 = 0.649 (m) (5)
Therefore, assuming that formulas (4), (5), Q = 1 (W), and aluminum material are used, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 6) is obtained.
A = LQ / (λΔT) = 0.649 × 1 / (206 × 4.4) = 0.000716 (m ² ) (6)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000716 / 0.06 × 1000 = 11.9 (mm)… (7)
It is.

(Heat transfer member D: green reflective liquid crystal panel to heat sink)
Similarly, if L = 0.056 + 0.145 + 0.36 = 0.561 (m), Q = 2 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following formula (8) is obtained.
A = 0.00124 (m ² )… (8)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.00124 / 0.06 × 1000 = 20.6 (mm)… (9)
It is. In addition, since the total heat quantity of the red and green reflective liquid crystal panels passes through the heat transfer member C, the thickness is 32.5 mm, which is a combination of the equations (7) and (9).

(Heat transfer member A: lamp to heat sink)
Similarly, when L = 0.31 (m), Q = 50 (W), ΔT = 4.4 (° C.), and λ = 206 (W / (m ° C.)) are substituted from FIG. can get.
A = 0.0171 (m ² )… (10)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0171 / 0.06 × 1000 = 285 (mm)… (11)
It is.

(Heat transfer member B: Blue reflective liquid crystal panel to heat sink)
Similarly, if L = 0.09 + 0.267 = 0.357 (m), Q = 3 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. Equation (12) is obtained.
A = 0.00118 (m ² )… (12)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.00124 / 0.06 × 1000 = 19.7 (mm)… (13)
It is.

(Heat transfer member A: transistor to heat sink)
Similarly, when substituting L = 0.18 (m), Q = 62 (W), ΔT = 4.4 (° C.), and λ = 206 (W / (m ° C.)) from FIG. can get.
A = 0.0123 (m ² )… (14)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0171 / 0.06 × 1000 = 205.2 (mm)… (15)
It is. In addition, since the heat transfer member A passes through the total amount of heat of the red, green, and blue reflective liquid crystal panels, the lamp, and the transistor, the thickness is expressed by the equations (7), (9), (11), (13), It will be 542.4mm which added (15).

(Comparative Example 1)
FIG. 4 shows the arrangement of the components of the projector of the comparative example.
The projector shown in FIG. 4 includes a power supply circuit, a lamp, a reflection type liquid crystal panel (light valve), and a heat sink similar to the projector shown in FIG. The position is changed to a position close to the reflective liquid crystal bulb (the lower position in FIG. 4).
Hereinafter, the design of the heat transfer member in this configuration will be described.

(Heat transfer member AA: transistor to heat sink)
From FIG. 4, the longest distance between the transistor and the end of the heat sink is
L = 0.18 + 0.36 = 0.54 (m) (16)
It is. Therefore, assuming that formulas (4), (16), Q = 62 (W), and aluminum material are used, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 17) is obtained.
A = LQ / (λΔT) = 0.54 × 62 / (206 × 4.4) = 0.0369 (m ² ) (17)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0369 / 0.06 × 1000 = 616 (mm)… (18)
It is.

(Heat transfer member AB: Blue reflective liquid crystal panel to heat sink)
Similarly, if L = 0.093 + 0.36 = 0.453 (m), Q = 3 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. Equation (19) is obtained.
A = 0.00150 (m ² )… (19)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0015 / 0.06 × 1000 = 25 (mm)… (20)
It is. In addition, since the total heat quantity of the transistor and the blue reflective liquid crystal panel passes through the heat transfer member AC, the thickness is 641 mm, which is a combination of the equations (18) and (20).

(Heat transfer member AD: lamp to heat sink)
Similarly, if L = 0.05 + 0.36 = 0.365 (m), Q = 50 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG.
A = 0.0201 (m ² )… (21)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0201 / 0.06 × 1000 = 336 (mm)… (22)
It is. Since the heat transfer member AD passes through the total amount of heat of the transistor, the blue reflective liquid crystal panel, and the lamp, the thickness is 977 mm, which is a combination of the equations (18), (20), and (22).

(Heat transfer member AG: Red reflective liquid crystal panel to heat sink)
Similarly, if L = 0.093 + 0.36 = 0.453 (m), Q = 1 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. Equation (23) is obtained.
A = 0.00050 (m ² )… (23)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.00050 / 0.06 × 1000 = 8.3 (mm) (24)
It is.

(Heat transfer member AF: Green reflective liquid crystal panel to heat sink)
Similarly, if L = 0.056 + 0.303 = 0.359 (m), Q = 2 (W), ΔT = 4.4 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. Equation (25) is obtained.
A = 0.000792 (m ² )… (25)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000792 / 0.06 × 1000 = 13.2 (mm)… (26)
It is. Note that the heat transfer member AE passes through the total amount of heat of the transistor, the blue, green, and red reflective liquid crystal panels and the lamp, and thus the thickness is expressed by the equations (18), (20), (22), (24), (26 ) Is 998.5mm.

  As is clear from Example 1 and Comparative Example 1 above, the size of the base plate is set to Comparative Example 1 by setting the distance between the transistor and the heat sink <the distance between the lamp and the heat sink according to the amount of heat generated by the transistor> the amount of heat generated by the lamp. In Example 1, it was 1345 (mm) × 1359 (mm), whereas in Example 1, the size could be reduced to 750.3 (mm) × 392.5 (mm).

[Second Embodiment]
Next, a second embodiment of the projector according to the present invention will be described.
FIG. 5 is a diagram showing a projector 40 according to the second embodiment. Components having the same functions as those of the first embodiment shown in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

As in the first embodiment, the projector 40 has three reflective liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate reflection type liquid crystal projector provided with a panel.
Further, unlike the first embodiment, the projector 40 has a power supply circuit (power supply unit) separately from the main body.

  That is, as shown in FIG. 6, a power supply unit 41 (AC adapter), which is one of the heat generating components, is arranged outside the projector body.

  Returning to FIG. 5, the light source 11 (lamp), the light valves 20, 21, and 22, and the liquid crystal driving circuit, which are heat generating components, are mounted on the base plate 42. Note that the liquid crystal drive circuit is mounted on the surface of the base plate 42 opposite to the mounting surface of the other components, and is not shown.

The light source 11 and the light valves 20, 21, and 22 are each thermally connected to a heat sink 44 that is a heat radiator via a heat transfer member 43.
As the heat sink 44, for example, one having a plurality of plate-like fins is used.
Further, as the heat transfer member 43, a good heat conductor is preferably used, and for example, an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof is used.

Here, the heat generation amount of each heat generating component is the light source 11: 50W, the red light valve 20: 1W, the green light valve 21: 2W, and the blue light valve 22: 3W.
The plurality of heat generating components (light source 11, light bulbs 20, 21, 22) have a shorter thermal distance on the heat transfer member 43 to the heat sink 44 in descending order of the amount of heat generated. Yes.

  That is, since the heat generation amount is light source 11> light bulbs 20, 21, 22, the thermal distance to the heat sink 44 is light bulbs 20, 21, 22> light source 11.

  In the light valves 20, 21, and 22, the amount of heat generated is as follows: blue light valve 22 (B)> green light valve 21 (G)> red light valve 20 (R), (B> G> R) Therefore, the thermal distance to the heat sink 44 is: red light valve 20 (R)> green light valve 21 (G)> blue light valve 22 (B) (R> G> B) ing.

  With this configuration, in the projector 40 of this example, since the power supply unit, which is one of the heat generating components, is arranged outside the projector main body, the heat generation and noise of the power supply unit (power supply circuit) are caused by the liquid crystal drive circuit of the main body. And the influence on the optical system can be prevented.

  Further, in the projector 40 of this example, more heat is radiated from the heat-generating component (light source 11) having a larger heat generation amount, and heat is radiated from the heat-generating components (light valves 20, 21, 22) having a smaller heat generation amount. It is suppressed. Therefore, the temperature difference between the plurality of heat generating components is suppressed.

  In the projector 40 of this example, since the thermal distance (the length of the heat transfer member 43) on the heat transfer member 43 is determined based on the heat generation amount of each heat generating component, the shape of the heat transfer member 43 is determined. As a result, the volume of the heat transfer member 43 can be kept small. Therefore, the projector 40 can be downsized.

(Example 2)
Next, the effect of the heat countermeasure technique was examined for the projector 40 of the second embodiment shown in FIG. 5 (Example 2 and Comparative Example 2).
Here, halogen lamp 12V-50W (JCR12V-50WG / 32 made by Ushio Electric Co., Ltd.) is used, and heat sink is UB60-25B made by Alpha Co., Ltd. (heat resistance 1.3 ° C / W when air volume is 0.5m / sec) ) Was used.
Hereinafter, the design of the heat transfer member that thermally connects the lamp and the heat sink, the reflective liquid crystal panel (light valve), and the heat sink will be described.
In the following description, the unit of dimensions in the drawings is “mm”.

The amount of heat generated by the halogen lamp is 50 W, and the reflective LCD panel is 3 W for blue, 2 W for green, and 1 W for red.
Therefore, the heat sink dissipates 56W. Therefore, the temperature difference between the heat sink and the atmosphere is
56 (W) x 1.3 (° C / W) /3=24.2 (° C)… (27)
It becomes.
The operation compensation upper limit environmental temperature of this projector is 35 ° C. The component with the lowest upper limit temperature is a reflective liquid crystal panel, and its temperature is 65 ° C.
Therefore, the allowable temperature difference generated at both ends of the heat transfer member is expressed by the following equation (28) from the equation (27).
ΔT = 65−24.2−35 = 5.8 (℃)… (28)

(Heat transfer member D: Heat transfer member of red reflective liquid crystal panel and heat sink)
From FIG. 5, the maximum distance between the lamp and heat sink end is
L = 0.093 + 0.196 + 0.18 = 0.469 (m) (29)
It is. Therefore, assuming that formulas (28), (29), Q = 1 (W), and aluminum material are used, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 30) is obtained.
A = LQ / (λΔT) = 0.469 × 1 / (206 × 5.8) = 0.000393 (m ² ) (30)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000393 / 0.06 × 1000 = 6.5 (mm) (31)
It is.

(Heat transfer member C: green reflective liquid crystal panel to heat sink)
Similarly, when L = 0.056 + 0.145 + 0.18 = 0.382 (m), Q = 2 (W), ΔT = 5.8 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following equation (32) is obtained.
A = 0.000638 (m ² ) (32)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000638 / 0.06 × 1000 = 10.6 (mm)… (33)
It is. Since the total heat quantity of the red and green reflective liquid crystal panels passes through the heat transfer member E, the thickness is 17.1 mm, which is a combination of the equations (31) and (33).

(Heat transfer member B: Blue reflective liquid crystal panel to heat sink)
Similarly, if L = 0.09 + 0.093 = 0.183 (m), Q = 3 (W), ΔT = 5.8 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. Equation (34) is obtained.
A = 0.000459 (m ² ) (34)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000459 / 0.06 × 1000 = 7.7 (mm) (35)
It is.

(Heat transfer member A: lamp to heat sink)
Similarly, when L = 0.18−0.05 = 0.13 (m), Q = 50 (W), ΔT = 5.8 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. (36) is obtained.
A = 0.00544 (m ² )… (36)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.00544 / 0.06 × 1000 = 90.7 (mm)… (37)
It is. In addition, since the heat transfer member A passes the total amount of heat of the red, green and blue reflective liquid crystal panels in addition to the amount of heat of the lamp, the thickness can be expressed by the equations (31), (33), (35) and (37). The total is 115.5mm.

(Comparative Example 2)
FIG. 7 shows the arrangement of the components of the projector of the comparative example.
The projector shown in FIG. 7 includes a lamp, a reflective liquid crystal panel (light valve), and a heat sink similar to the projector shown in FIG. 5. The projector shown in FIG. 5 has a red reflective liquid crystal panel (R). And the blue reflective liquid crystal panel (B) are replaced with each other, and the heat sink is disposed away from the lamp (light source) on the back side of the blue reflective liquid crystal panel (B) (right side in FIG. 7). Is.
Hereinafter, the design of the heat transfer member in this configuration will be described.

(Heat transfer member F: Red reflective liquid crystal panel to heat sink)
From FIG. 7, the maximum distance between the lamp and heat sink end is
L = 0.09 + 0.093 + 0.196 + 0.93 = 0.472 (m) (38)
It is. Therefore, assuming that formulas (28), (38), Q = 1 (W), and aluminum material are used, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 39) is obtained.
A = LQ / (λΔT) = 0.472 × 1 / (206 × 5.8) = 0.000395 (m ² ) (39)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000395 / 0.06 × 1000 = 6.6 (mm) (40)
It is.

(Heat transfer member G: Heat transfer member of lamp and heat sink)
Similarly, when L = 0.05 + 0.196 + 0.093 = 0.339 (m), Q = 50 (W), ΔT = 5.8 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following formula (41) is obtained.
A = 0.0142 (m ² )… (41)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.0142 / 0.06 × 1000 = 236 (mm)… (42)
It is. In addition, since the heat transfer member G passes the total heat quantity of the red reflective liquid crystal panel in addition to the heat quantity of the lamp, the thickness is 243 mm including the expressions (40) and (42).

(Heat transfer member H: Green reflective liquid crystal panel to heat sink)
Similarly, when L = 0.056 + 0.04 + 0.093 = 0.189 (m), Q = 2 (W), ΔT = 5.8 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following formula (43) is obtained.
A = 0.000316 (m ² ) (43)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000316 / 0.06 × 1000 = 5.3 (mm)… (44)
It is. In addition, since the heat transfer member I passes through the total amount of heat of the green reflective liquid crystal panel in addition to the amount of heat of the red reflective liquid crystal panel and lamp, the thicknesses of the formulas (40), (42), and (44) are combined. 248mm.

(Heat transfer member J: Blue reflective liquid crystal panel to heat sink)
Similarly, when substituting L = 0.18 (m), Q = 3 (W), ΔT = 5.8 (° C.), and λ = 206 (W / (m ° C.)) from FIG. 7, the following equation (45) is obtained. can get.
A = 0.000452 (m ² ) (45)
Since the height of the heat sink is 60mm, the thickness required for the heat transfer member is
0.000452 / 0.06 × 1000 = 7.5 (mm) (46)
It is. In addition, since the heat transfer member J passes the total heat quantity of the red and green reflective liquid crystal panels in addition to the heat quantity of the lamp, the thicknesses are combined with the formulas (40), (42), (44) and (46). It becomes 255.4mm.

  As is clear from the above Example 2 and Comparative Example 2, the lamp calorific value> blue, red and green reflective liquid crystal panel according to the following: The distance between the lamp and the heat sink <blue, red and green reflective liquid crystal panel By using the distance between the heat sink and the heat sink, the size of the base plate is 694.4 (mm) x 473 (mm) in Comparative Example 2, whereas it is small as 311.5 (mm) x 231.5 (mm) in Example 2. I was able to.

[Third Embodiment]
Next, a third embodiment of the projector according to the present invention will be described.
FIG. 8 is a diagram showing a projector 50 according to the third embodiment, and this projector 50 is a modification of the projector 40 according to the second embodiment shown in FIG. Components having the same functions as those in the second embodiment shown in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

As in the second embodiment, the projector 50 has three reflective liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate reflection type liquid crystal projector provided with a panel.
Further, unlike the second embodiment, the projector 50 includes a plurality of heat generating components (light source 11, light valves 20, 21, and 22) and a housing 51 that are thermally connected.

The casing 51 is disposed so as to cover each component mounted on the base plate 42, and is thermally connected to the heat transfer member 43. That is, the base plate 42 and the heat sink 52 are thermally connected with a part of the casing 51 interposed therebetween.
Moreover, the housing | casing 51 is arrange | positioned so that the heat sink 52 may be covered, and has the metal-mesh part 52a in which the opening for allowing air to pass was formed.
In the housing 51, there are a support member for each component, rib stands for securing the strength of the housing 51, partitioning, routing electrical wiring, etc. (all not shown).
The projection system 24 is held in the lens barrel 53.

  As the material of the casing 51, a good heat conductor is preferably used. For example, in addition to an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof, copper, brass, gold, iron (and steel), nickel Various metals and alloys thereof are used.

  With this configuration, in the projector 50 of this example, the heat of the plurality of heat generating components (the light source 11, the light valves 20, 21, and 22) is transmitted to the housing 51 through the heat transfer member 43, and the heat is transmitted to the housing 51. Radiates heat from the outside. Since the heat of the plurality of heat generating components is also dissipated from the casing 51, the thermal load on the heat sink 52 is reduced, the volume of the heat sink 52 can be reduced, and the apparatus can be downsized.

In the projector 50 described above, the casing 51 has twice the total surface area of the upper bottom surface arranged in the vertical direction as compared to the total surface area of the plurality of side surfaces arranged in the horizontal direction. Is preferably exceeded.
According to this configuration, since the area of the upper surface with high heat dissipation efficiency is sufficiently large, the heat dissipation efficiency from the housing 51 is increased. Therefore, the volume of the heat sink 52 can be reduced, and the apparatus can be downsized.

(Example 3)
Next, the effect of the heat countermeasure technique was examined for the projector 50 of the third embodiment shown in FIG. 8 (Example 3 and Comparative Example 3).
Here, the casing was made of aluminum having a thickness of 1.5 mm. In the range of ABE-ABF in the figure, a heat conduction path is formed with the casing → heat transfer member → each heat generating component and is thermally connected.
Further, since the heat sink is at a high temperature, the heat sink is surrounded by a metal mesh so as not to be directly touched by the user and to ensure a sufficient air flow rate.
In addition, each heat generating component was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured for the heat sink protrusion length LA at different levels.

The temperature rise reached saturation 45 minutes after turning on the power. The temperature at that time is shown in Example 3 and Experimental Examples 1 and 2 in the table of FIG.
The measurement environment temperature is 35 ° C., and the component with the lowest upper limit temperature is the reflective liquid crystal panel, and the temperature is 65 ° C.

Here, the upper base area of the housing in Example 3 and Experimental Examples 1 and 2 is expressed by the following equation (47) in consideration of the fact that the contribution rate to the heat dissipation of the wire mesh part is negligible. .
0.4 × 0.525 = 0.21 (m ² )… (47)
The side area that contributes to heat dissipation, excluding the range that is thermally connected to the ABD-ABA heat sink in the figure,
((0.4 + 0.525) × 2−0.18) × 0.06 = 0.10 (m ² )… (48)
It is. From Equations (47) and (48), the relationship of (upper bottom area)> (side area) × 2 of the housing contributing to heat dissipation is established.

Heat transfer engineering / Ichimatsu Yashita / Hanafusa / Fifth edition of 1993, page 167, or page 168, 6.2 table shows a simple formula for the natural convection heat transfer coefficient of objects in the air.
(A) Heat transfer coefficient of vertical flat plate = 1.42 (Δt / L) ^0.25
(B) Heat transfer coefficient of horizontal flat plate (heated upward surface) = 1.32 (Δt / L) ^0.25 ,
(Δt is the temperature difference between the flat plate and the atmosphere, L is the representative length, for example, the length of one side if square.)
It is shown that.

That is, if a flat plate of the same size is used, the heat radiation from both sides of the vertically standing flat plate and the heat radiation from the top surface of the horizontal flat plate are substantially equal.
Here, considering the fact that the side of the housing contributes to heat dissipation is the surface facing the outside air, the top surface of the flat plate is horizontal twice as much as the heat dissipation from one side of the vertical plate It is almost equal to the heat dissipation from.
Therefore, by increasing the area of the upper base more than twice the side area of the casing that contributes to heat dissipation, the heat dissipation efficiency from the casing can be further increased.

(Comparative Example 3)
FIG. 10 shows the arrangement of the constituent members of the projector of the comparative example.
The projector shown in FIG. 10 has substantially the same configuration as the projector shown in FIG. 8, and a plurality of heat generating components (lamp (light source), reflective liquid crystal panel (light valve)) and the housing are thermally connected. Has been.
Further, the projector shown in FIG. 10 has a casing whose height is doubled (height 120) as compared with the projector shown in FIG.
Although not shown in the figure, in the space on the back side of the base plate, there are a support member for each component, a rib stand for ensuring the strength of the casing, a partition, a routing electrical wiring, and the like.
The casing is made of aluminum with a thickness of 1.5 mm. Within the range of ACE-ACF in the figure, a heat conduction path is formed with the casing → heat transfer member → each heat generating component and is thermally connected.
Since the heat sink is hot, it is surrounded by a metal mesh so that the user cannot touch it directly and to secure a sufficient air flow.

At this time, the volume of the casing excluding the wire mesh portion is expressed by the following equation (49).
0.35 × 0.3 × 0.12 = 0.0126 (m3)… (49)
The volume of the casing excluding the wire mesh part in FIG.
0.4 × 0.525 × 0.06 = 0.0126 (m3)… (50)
The size of the housing that contributes to heat dissipation is almost the same in Example 3 and Comparative Example 3.
Further, the upper base area of the housing of FIG. 8 is expressed by the following equation (51) in consideration of the fact that the contribution ratio of the wire mesh portion to the heat dissipation is negligible.
0.35 × 0.3 = 0.105 (m ² ) (51)
At this time, the side area contributing to heat dissipation is excluding the area thermally connected to the ACD-ACA heat sink in the figure (the heat sink height is 60 mm and the housing height is 120 mm). (Considering (mm))
(0.35 + 0.3) × 2 × 0.12-0.18 × 0.06 = 0.145 (m ² )… (52)
It is. From equations (51) and (52), the relationship of (upper bottom area) <(side area) × 2 of the housing contributing to heat dissipation is established.

Each heat generating component was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured for the heat sink protrusion length LB at different levels.
The temperature rise reached saturation 45 minutes after turning on the power. The temperature at that time is shown in Comparative Example 3 and Experimental Examples 3 and 4 in the table of FIG.

  As is apparent from the evaluation results of Example 3 and Comparative Example 3 shown in the table of FIG. 9, the housing and the heat-generating component are thermally connected, and the size (volume) of the housing is not changed. It was found that by setting (upper bottom area)> (side area) × 2, the heat dissipation efficiency from the casing is increased, and the protruding length of the heat sink can be reduced.

[Fourth Embodiment]
Next, a fourth embodiment of the projector according to the present invention will be described.
FIG. 11 is a diagram schematically showing a schematic overall configuration of a projector 110 according to the fourth embodiment.
Here, as a fourth embodiment, three liquid crystal devices corresponding to three colors of R (red), G (green), and B (blue) are used as light modulation means (light valves) (in this example, transmission). A three-plate transmissive liquid crystal projector provided with a liquid crystal panel) will be described.
In FIG. 11, a projector 110 includes light sources 111, 112, 113, liquid crystal light valves 114, 115, 116 that modulate each light from the light sources 111, 112, 113, a cross dichroic prism 117 that synthesizes each modulated light, And a projection system 118 for enlarging and projecting the light emitted from the prism 117 onto a screen (not shown). Here, the light source 111 emits light of R (red), 112 emits light of G (green), 113 emits light of B (blue), the light valve 114 emits light of R, 115 of G, and 116 of light of B. It corresponds to each.

  As the light sources 111, 112, and 113, LED light sources (LED lamps) including LEDs (light emitting diodes, organic electroluminescent elements) as light emitting elements are used. The LED light source is advantageous in reducing the size of the apparatus.

  The light valves 114, 115, 116 include, for example, a thin film transistor (TFT) as a switching element and a transmissive liquid crystal cell, and light sources 111, 112 based on image information (or video information) from the outside. , 113 are modulated.

  The prism 117 has a structure in which four right-angle prisms are bonded together, and the whole is formed in a substantially cubic shape. The prism 117 includes a dielectric multilayer film 117a that reflects red light (R) and a dielectric multilayer film 117b that reflects blue light (B), and transmits the green light (G) from the light valve 115. Further, the red light (R) from the light valve 114 and the blue light (B) from the light valve 116 are bent to combine these three colors of light to form a color image.

  The projection system 118 includes an enlarged projection optical system, and projects the light emitted from the prism 117 onto a screen (not shown). By this projection, an enlarged color image is displayed on the screen.

FIG. 12 is a plan view schematically showing how the constituent members are arranged in the projector 110.
In FIG. 12, each component described above is mounted on a base plate 120. The base plate 120 is also mounted with a light valve driving circuit (liquid crystal driving circuit), but is mounted on the surface opposite to the mounting surface of other components, and is not shown.
Similarly to the projector shown in FIG. 6, a power supply unit (AC adapter), which is one of the heat generating components, is disposed outside the projector main body. Thus, in the projector 110, the influence of the heat generation and noise of the power supply unit (power supply circuit) on the liquid crystal drive circuit and the optical system of the main body is prevented.

  In this projector 110, in particular, the amount of heat generated by the light sources 111, 112, and 113 (LED lamps) is relatively large, and these heat generating components (the light sources 111, 112, and 113) serve as heat radiators via the heat transfer member 131. The heat sink 125 is thermally connected.

  As the heat sink 125, for example, one having a plurality of plate-like fins is used. Note that the heat sink is not limited to a form having a plurality of plate-like fins, but may have another form. Moreover, it may replace with a heat sink and you may use another thermal radiation means (for example, cooling fin). Since the heat sink does not have a drive mechanism, there is an advantage that it is easy to reduce the size.

  As the heat transfer member 131, a good heat conductor is preferably used. For example, in addition to an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof, copper, brass, gold, iron (and steel), Various metals such as nickel and alloys thereof are used.

Here, the calorific values (power consumption here) of the light sources 111, 112, and 113 are as follows: red light source 111 (R): 1.6W, green light source 112 (G): 6.1W, blue light source 113 ( B): 2.3 W.
The plurality of heat generating components (light sources 111, 112, 113) have a shorter thermal distance on the heat transfer member 131 to the heat sink 125 in descending order of the heat generation amount.

  That is, in the light sources 111, 112, and 113, the amount of heat generation is green light source 112> blue light source 113> red light source 111 (G> B> R). Therefore, the thermal distance to the heat sink 125 is red light source 111> blue light source 113> green light source 112 (R> B> G).

  With this configuration, in the projector 110 of this example, more heat is radiated from the heat-generating component (light source 112) having a larger amount of heat generation, and heat radiation from the heat-generating components (light sources 111 and 113) having a smaller heat generation amount is suppressed. Is done. Therefore, the temperature difference between the plurality of heat generating components is suppressed.

  Further, in the projector 110 of this example, since the thermal distance (the length of the heat transfer member 131) on the heat transfer member 131 is determined based on the heat generation amount of each heat generating component, the shape of the heat transfer member 131 is determined. As a result, the volume of the heat transfer member 131 can be kept small. Therefore, the projector 110 can be downsized.

  Here, as described above, the heat sink 125 has a plurality of plate-like fins. In this case, as shown to Fig.13 (a), it is preferable to distribute | arrange so that the clearance gap between several fins may extend in a perpendicular direction.

  That is, the heat sink 125 shown in FIG. 13A has a configuration in which a plurality of plate-like fins (fins 125b) are erected on the base 125a. The plurality of fins 125b are arranged in a row so that the heat transfer surfaces (heat dissipation surfaces) face each other, and the row direction is a horizontal direction. By arranging the plurality of fins 125b in the horizontal direction, the gaps between the heat transfer surfaces of the plurality of fins 125b extend in the vertical direction.

  In the heat sink 125 shown in FIG. 13A, since the gaps between the heat transfer surfaces of the plurality of fins 125b extend in the vertical direction, the air heated by the fins 125b is likely to rise. Air can easily flow between the two, improving the heat dissipation efficiency.

  On the other hand, for example, in the heat sink shown in FIG. 13B, since the gaps between the heat transfer surfaces of the plurality of fins extend in the horizontal direction, the air warmed by the fins is blocked by the fins. It is hard to rise and tends to cause a decrease in heat dissipation efficiency.

In addition, it is preferable that the heat emissivity of the heat sink 125 shown in FIG.12 and FIG.13 (a) is 0.5 or more, and it is more preferable that it is 0.9 or more. For example, by applying black paint to the heat transfer surface, the heat emissivity of the heat transfer surface can be set to 0.95.
When the heat emissivity of the heat sink 125 is 0.5 or more, heat is radiated well from the heat sink 125 into the air, and the heat dissipation efficiency of the heat sink 125 is improved. Therefore, the heat sink 125 can be downsized.

Example 4
Next, the effects of the heat countermeasure technology were examined for the projector 110 of the fourth embodiment shown in FIG. 12 (Examples 4, 5, and 6, Comparative Examples 4, 5, and 6).
Here, an LED lamp (Luxeon series manufactured by LumiLeds) was used as the lamp (light source). Power consumption is 1.6W red, 6.1W green, and 2.3W blue. One UB35-10B manufactured by Alpha Co., Ltd. (thermal resistance 5 ° C./W when air volume is 0.5 m / sec) was used as the heat sink.

Hereinafter, the design of the heat transfer member that thermally connects the LED lamp and the heat sink will be described.
In the following description, the unit of dimensions in the drawings is “mm”.

The total amount of heat generated by the LED lamp is 10W.
Therefore, the heat sink dissipates 10W. Therefore, the temperature difference between the heat sink and the atmosphere is
10 (W) x 5 (℃ / W) = 50 (℃) (53)
It becomes.
The operation compensation upper limit environmental temperature of this projector is 35 ° C. The upper limit temperature of the PN junction of the LED element is 90 ° C.
Therefore, the allowable temperature difference generated at both ends of the heat transfer member is expressed by the following equation (54) from the equation (53).
ΔT = 90−50−35 = 5 (℃)… (54)

(Heat transfer member AA: Red LED lamp to heat sink)
From FIG. 12, the longest distance between the lamp and heat sink end is
L = 0.025 + 0.048 + 0.0175 = 0.0905 (m) (55)
It is. Therefore, assuming that formulas (54), (55), and Q = 1.6 (W), aluminum material is adopted, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 56) is obtained.
A = LQ / (λΔT) = 0.0905 × 1.6 / (206 × 5) = 0.00014 (m ² ) (56)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.00014 / 0.035 × 1000 = 4.0 (mm) (57)
It is.

(Heat transfer member AB: Blue LED lamp-Heat sink)
Similarly, when L = 0.025 + 0.048 + 0.0175 = 0.0905 (m), Q = 2.3 (W), ΔT = 5 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following formula (58) is obtained.
A = 0.000202 (m ² ) (58)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.000202 / 0.035 × 1000 = 5.7 (mm)… (59)
It is.

(Heat transfer member AC: Green LED lamp-Heat sink)
Similarly, when L = 0.0175 (m), Q = 6.1 (W), ΔT = 5 (° C.), and λ = 206 (W / (m ° C.)) are substituted from FIG. can get.
A = 0.000104 (m ² )… (60)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.000104 / 0.035 × 1000 = 3.0 (mm)… (61)
It is. In addition, since the total heat quantity of each color LED lamp passes through the heat transfer member AC, the thickness becomes 12.7 mm which is a combination of the equations (57), (59), and (61).

(Comparative Example 4)
FIG. 14 shows the arrangement of the components of the projector of the comparative example.
The projector shown in FIG. 14 includes a light source (LED lamp), a transmissive liquid crystal panel (light valve), and a heat sink similar to the projector shown in FIG. R) and the arrangement position of the green LED lamp (G) are interchanged.
Hereinafter, the design of the heat transfer member in this configuration will be described.

(Heat transfer member AD: green LED lamp ~ heat sink)
From FIG. 14, the maximum distance between the lamp and heat sink end is
L = 0.025 + 0.048 + 0.0175 = 0.0905 (m) (62)
It is. Therefore, assuming that formulas (54), (62), and Q = 6.1 (W), aluminum material is adopted, substituting λ = 206 (W / (m ° C)) into formula (2), the following formula ( 63) is obtained.
A = LQ / (λΔT) = 0.0905 × 6.1 / (206 × 5) = 0.000536 (m ² ) (63)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.000536 / 0.035 × 1000 = 15.3 (mm)… (64)
It is.

(Heat transfer member AE: Blue LED lamp-Heat sink)
Similarly, when L = 0.025 + 0.048 + 0.0175 = 0.0905 (m), Q = 2.3 (W), ΔT = 5 (° C.), λ = 206 (W / (m ° C.)) are substituted from FIG. The following formula (65) is obtained.
A = 0.000202 (m ² )… (65)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.000202 / 0.035 × 1000 = 5.7 (mm)… (66)
It is.

(Heat transfer member AF: Red LED lamp to heat sink)
Similarly, when L = 0.0175 (m), Q = 1.6 (W), ΔT = 5 (° C.), and λ = 206 (W / (m ° C.)) are substituted from FIG. can get.
A = 0.0000271 (m ² ) (67)
The height of the heat sink is 35mm, so the thickness required for the heat transfer member is
0.0000271 / 0.035 × 1000 = 0.8 (mm)… (68)
It is. In addition, since the total heat quantity of each color LED lamp passes through the heat transfer member AF, the thickness is 21.8 mm including the formulas (64), (66), and (68).

  As is clear from Example 4 and Comparative Example 4 above, the heat generation amount of the green LED lamp> the heat generation amount of the blue LED lamp> the heat generation amount of the red LED lamp (G> B> R). <The distance between the blue LED lamp and the heat sink <the distance between the red LED lamp and the heat sink (R> B> G) In the comparative example 4, the size of the base plate is 117.0 (mm) × 171.8 (mm) On the other hand, in Example 4, the size could be reduced to 105.7 (mm) × 162.7 (mm).

(Example 5, Comparative Example 5)
Next, with respect to the projector 110 of the fourth embodiment shown in FIG. 12, the heat radiation effect due to the feature of the heat sink was examined (Example 5, Comparative Example 5).
As the heat sink, the Alpha UB series is used, and the heat transfer surfaces of the fins are arranged in the vertical direction as shown in FIG. 13 (a) (Example 5) and as shown in FIG. 13 (b). The heat radiation characteristics were evaluated with respect to the configuration (Comparative Example 5) in which the heat transfer surfaces of the fins were arranged in the horizontal direction.

In both Example 5 and Comparative Example 5, the temperature increase reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in the table of FIG.
In Comparative Example 5, the LED lamp of the projector was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured by attaching heat sinks having the same fin structure and dimensions and different bottom areas (Comparative Example). 5a, 5b, 5c).

  As is apparent from the evaluation results of Example 5 and Comparative Example 5 (Comparative Examples 5a, 5b, and 5c) shown in the table of FIG. 15, the heat sink is attached in the vertical direction (the heat transfer surface of the fin is in the vertical direction). Thus, it was found that the heat dissipation efficiency of the heat sink is high, and the bottom area of the heat sink (the area of the base to which the fins are attached, which is proportional to the overall size) can be reduced.

(Example 6, Comparative Example 6)
Next, for the projector 110 of the fourth embodiment shown in FIG. 12, the heat radiation effect by the heat emissivity of the surface of the heat sink was examined (Example 6, Comparative Example 6).
As a heat sink, a UB series manufactured by Alpha Co., Ltd. was used, and when the fin was black coated, the thermal emissivity was ε black = 0.95 (Example 6).
When heat sinks with the same structure and dimensions were used and the fins were not painted black, the thermal emissivity was ε aluminum = 0.06.
The method of measuring the thermal emissivity is to apply black body tape (emissivity ε = 0.93) to the heat sink and change the emissivity parameter of the measurement object of the radiation thermometer to indicate the same temperature as the black body tape. This was done by reading the value of.

In both Example 6 and Comparative Example 6, the temperature increase reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in the table of FIG.
In Comparative Example 6, the projector's LED lamp was replaced with a resistor with the same calorific value, and the temperature of the resistor was measured by attaching a heat sink without black paint with the same fin structure and dimensions but different bottom area. (Comparative Examples 6a, 6b, 6c).

  As is apparent from the evaluation results of Example 6 and Comparative Example 6 (Comparative Examples 6a, 6b, 6c) shown in the table of FIG. 16, the heat sink is given a black paint (thermal emissivity of 0.5 or more). It was found that the heat dissipation efficiency of the heat sink was high and the bottom area of the heat sink (proportional to the overall size) could be reduced.

[Fifth Embodiment]
Next, a fifth embodiment of the projector according to the invention will be described.
FIG. 17 is a diagram showing a projector 150 according to the fifth embodiment, and this projector 150 is a modification of the projector 110 according to the fourth embodiment shown in FIGS. 11 and 12 above. . In addition, the component which has the same function as the 4th Example shown in FIG.11 and FIG.12 attaches | subjects the same code | symbol, The description is abbreviate | omitted or simplified.

Similar to the fourth embodiment, the projector 150 has three transmissive liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate transmissive liquid crystal projector provided with a panel.
Similarly to the fourth embodiment, the projector 150 includes light sources (LED lamps) 111, 112, and 113, and light valves (transmission type liquid crystal panels) 114, corresponding to the R, G, and B lights. 115 and 116, and the light sources 111, 112, and 113 are thermally connected to a heat sink 151 as a radiator through a heat transfer member 131.
Note that a power supply unit (AC adapter), which is one of the heat generating components, is arranged outside the projector body.
Also, unlike the fourth embodiment, the projector 150 has a larger surface area as the heat sink 151 is closer to the light sources 111, 112, and 113.

  That is, each of the light sources 111, 112, and 113 is disposed on one heat absorbing surface (base surface) side of the heat sink 151, and is thermally connected to the one heat absorbing surface via the heat transfer member 131. . Further, the heat sink 151 has the largest shape in the longitudinal section direction (direction orthogonal to the paper surface of FIG. 17) in the vicinity of the one heat absorbing surface, and the sectional shape is made smaller as the distance from the one heat absorbing surface increases.

  More specifically, the heat sink 151 has a cross-sectional shape shown in FIG. 17 (a cross-section in a direction parallel to the paper surface of FIG. 17) having a base on one heat absorbing surface (base surface), and a predetermined distance from the base. It is formed in a triangular shape having a vertex at a height (in a direction away from the heat transfer member 131). In this example, the apex of the triangle is provided on a line passing through the arrangement position of the green light source 112 (G) and perpendicular to the base of the triangle. As a result, the heat sink 151 has a larger surface area as it is closer to the light sources 111, 112, and 113 (strictly, the green light source 112) that is a heat-generating component, and a smaller surface area as it is farther away.

  In the heat sink 151, since the heat amount passing through the portion closer to the heat generating component (light source 111, 112, 113) is larger, the heat radiation efficiency is improved by forming the surface area of the portion larger. Further, in the heat sink 151, since the amount of heat passing therethrough is relatively small in a portion away from the heat generating component (light source 111, 112, 113), the shape of the heat sink 151 is optimized by forming a small surface area. Therefore, the volume can be kept small. Thereby, in the projector 150 of this example, the apparatus can be reduced in size.

  In the projector 150 described above, the surface area of the heat sink for each portion is changed by changing the overall shape of the heat sink, but the present invention is not limited to this. That is, for each portion, the surface area of the heat sink may be changed by changing the arrangement density of the plurality of fins or changing the shape of the fins.

(Example 7)
Next, the effect of the heat countermeasure technique was examined for the projector 150 of the fifth embodiment shown in FIG. 17 (Example 7 and Comparative Example 7).
Three heat sinks, UB35-10B manufactured by α, were processed and used.
In the following description, the unit of dimensions in the drawings is “mm”.

Point P1-1, point P1-2, point P1-3 shown in FIG. 17: light emitting part (heat generating part) of heat-generating component (green, red, blue LED lamp), point P2-1: maximum heat-generating component (green LED lamp) The portion of the heat sink closest to), points P3-1 and P3-2: A thermocouple was attached to the portion of the heat sink farthest from the largest heat generating component (green LED lamp), and the temperature was measured (Example 7).
The upper limit temperature of each LED lamp is 90 ° C, and if it exceeds this temperature, it will be damaged or its life will be shortened, so a resistor of 23.6Ω (0.51A at 12V, ie 6.1W heat generation) (Nikko Corp. Metal film resistor RNP-5 type with heat sink connection structure) was used as a heat generating component instead of a green LED lamp.
Similarly, a 90Ω resistor (0.13A at 12V, ie 1.6W heat generation) is replaced with a red LED lamp, and a 62.6Ω resistor (0.19A at 12V, ie 2.3W heat generation) is replaced with a blue LED lamp. Used as.
In addition, the unit was placed in a 1 m square transparent acrylic resin box so that the influence of wind from the outside was removed and the atmosphere would be natural convection. The ambient temperature was kept at 35 ° C using a constant temperature room.

  The temperature rise reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in the table of FIG. As an experiment, data when the level of the protrusion length H1 of the heat sink shown in FIG. Furthermore, the area of the bottom surface of the heat sink is also shown. This bottom area is proportional to the total surface area of fins of the heat sink (area of heat transfer surface / heat dissipation surface).

(Comparative Example 7)
FIG. 19 shows the arrangement of the components of the projector of the comparative example.
The projector shown in FIG. 19 has the same configuration as the projector shown in FIG. In this projector, the surface area of the heat sink is constant regardless of the distance from the heat generating component (LED lamp). That is, the cross-sectional shape in the longitudinal cross-sectional direction (direction orthogonal to the paper surface of FIG. 19) in the vicinity of one heat absorbing surface shown in FIG. 19 is the same as the cross-sectional shape in a position away from the one heat absorbing surface.
UB35-10B manufactured by α Co. was used as the heat sink.

A resistor is installed in place of the LED lamp as a heat-generating component, and points P4-1, P4-2, and P4-3 shown in Fig. 19: Light-emitting part (heat-generating part) of heat-generating parts (green, red, and blue LED lamps) , Point P5-1: heatsink part closest to the largest heat generating component (green LED lamp), point P6-1, point P6-2: thermocouple attached to the heatsink part farthest from the largest heat generating component (green LED lamp) Baking temperature was measured. The measuring method is the same as in Example 7.
The temperature rise reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in Comparative Example 7 in the table of FIG.

  As is clear from the evaluation results of Example 7 and Comparative Example 7 shown in the table of FIG. 18, the heat sink heat dissipation efficiency is increased by forming the surface area closer to the heat generating component (maximum heat generating component). As a result, it was found that the bottom area of the heat sink (the overall surface area of the heat sink, that is, proportional to the overall size) can be reduced.

[Sixth Embodiment]
Next, a sixth embodiment of the projector according to the present invention will be described.
FIG. 20 is a diagram showing a projector 160 according to the sixth embodiment, and this projector 160 is a modification of the projector 110 according to the fourth embodiment shown in FIGS. 11 and 12 above. . In addition, the component which has the same function as the 4th Example shown in FIG.11 and FIG.12 attaches | subjects the same code | symbol, The description is abbreviate | omitted or simplified.

Similar to the fourth embodiment, the projector 160 has three transmissive liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate transmissive liquid crystal projector provided with a panel.
Similarly to the fourth embodiment, the projector 160 includes light sources (LED lamps) 111, 112, and 113 and light valves (transmission type liquid crystal panels) 114, corresponding to the R, G, and B lights. 115 and 116, and the light sources 111, 112, and 113 are thermally connected to a heat sink 161 as a heat radiator via a heat transfer member 131.
Note that a power supply unit (AC adapter), which is one of the heat generating components, is arranged outside the projector body.
Further, unlike the fourth embodiment, the projector 160 includes a light source 111, 112, 113, which is a heat generating component, and a housing 162 that are thermally connected.

The casing 162 is disposed so as to cover each component mounted on the base plate 120, and is thermally connected to the heat transfer member 131. That is, the base plate 120 and the heat sink 161 are thermally connected with a part of the casing 162 interposed therebetween.
The casing 162 includes a wire mesh portion 162a that is disposed so as to cover the heat sink 161 and that has an opening for allowing air to pass therethrough.
In the housing 162, there are a support member for each component, a rib stand for securing the strength of the housing 162, a partition, a routing electrical wiring, and the like (all not shown).
Further, the projection system 118 is held in the lens barrel 163.

  As the material of the housing 162, a good heat conductor is preferably used. For example, in addition to an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof, copper, brass, gold, iron (and steel), nickel Various metals and alloys thereof are used.

  With this configuration, in the projector 160 of this example, the heat of the plurality of heat generating components (light sources 111, 112, 113) is transmitted to the housing 162 via the heat transfer member 131, and the heat is radiated from the housing 162 to the outside. Is done. Since the heat of the plurality of heat generating components is also radiated from the housing 162, the thermal load on the heat sink 161 is reduced, the volume of the heat sink 161 can be reduced, and the apparatus can be downsized.

  In the projector 160 described above, it is preferable that the heat absorption rate of the inner surface of the housing 162 is 0.5 or more. For example, by applying black coating to the inner surface of the housing 162, the heat absorption rate can be set to 0.95.

  When the heat absorption rate of the inner surface of the housing 162 is 0.5 or more, the heat inside the housing 162 is well absorbed by the housing 162, and the heat is radiated to the outside of the housing 162. Therefore, the temperature rise inside the housing 162 is suppressed, and the thermal load on the heat sink 161 is reduced.

  In the projector 160 described above, the thermal emissivity of the outer surface of the housing 162 is preferably 0.5 or more. For example, by applying black coating to the outer surface of the housing 162, the thermal emissivity can be set to 0.95.

When the thermal emissivity of the outer surface of the housing 162 is 0.5 or more, heat is radiated well from the housing 162 to the outside air, and the heat dissipation efficiency from the housing 162 is increased.
Further, by improving the heat dissipation efficiency from the housing 162, the volume of the heat sink 161 can be further reduced, and the apparatus can be downsized.

(Example 8)
Next, the effect of the heat countermeasure technique was examined for the projector 160 of the sixth embodiment shown in FIG. 20 (Examples 8, 9, 10 and Comparative Examples 8, 9, 10).
Here, the casing was made of aluminum having a thickness of 1.5 mm. Within the range of AAA-AAB in the figure, a heat conduction path is formed with the housing → heat transfer member → each LED lamp and is thermally connected.
Further, since the heat sink is at a high temperature, the heat sink is surrounded by a metal mesh so as not to be directly touched by the user and to ensure a sufficient air flow rate.
Moreover, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured for lamps having different levels of the heat sink protrusion length L.

  The temperature rise reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in Example 8 and Experimental Examples 1 and 2 in FIG.

(Comparative Example 8)
FIG. 22 shows the arrangement of the constituent members of the projector of the comparative example.
Although the projector shown in FIG. 22 has substantially the same configuration as the projector shown in FIG. 20, a plurality of heat generating components (LED lamps (light sources)) and the housing are not thermally connected.
Here, each LED lamp was replaced with a resistor having the same calorific value, and the heat sink protrusion length was L = 10.

  The temperature rise of the resistor reached saturation 30 minutes after power-on. The temperature at that time is shown in Comparative Example 8 in FIG.

  As is apparent from the evaluation results of Example 8 and Comparative Example 8 shown in the table of FIG. 21, the protruding length of the heat sink can be reduced by thermally connecting the casing and the heat generating component (each LED lamp). I understood it.

(Example 9, Comparative Example 9)
Next, for the projector 110 of the fourth embodiment shown in FIG. 20, the effect of heat absorption on the inner surface of the casing was examined (Example 9, Comparative Example 9).
Here, black coating (heat absorption rate α = 0.95) was applied to the inner surface of the projector casing shown in FIG.
Moreover, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured for lamps having different levels of the heat sink protrusion length L.
In addition, a thermocouple was attached to the housing surface, and the temperature of the housing surface was also measured. The measurement points are points P7-1, P7-2, P7-3, and point P8 shown in FIG.
Point P7-1 is directly above the red LED, P7-2 is directly above the green LED, and P7-3 is directly above the blue LED. The point P8 is located above the lenses and far from the heat generating component.

The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The temperature at that time is shown in Example 9 and Experimental Examples 1 and 2 in the table of FIG.
In the table of FIG. 24, measurement data in the case of the projector shown in FIG. 20 when the inside of the housing is an aluminum surface, that is, metallic luster (α = 0.055) is also shown as a comparative example (comparative example 9). Note that Comparative Example 9 shown in the table of FIG. 24 has substantially the same conditions as Comparative Example 8 shown in the table of FIG.
Further, the heat sink protrusion length “L = 0” in the table of FIG. 24 indicates that the heat sink is not attached (therefore, there is no metal mesh part of the housing). However, as shown in FIG. 20, the heat transfer member and the casing are thermally connected to the casing in the range of AAA-AAB.

As is apparent from the evaluation results of Example 9 and Comparative Example 9 shown in the table of FIG. 24, the amount of radiant heat absorbed from the heat-generating component can be increased by applying black coating to the inner surface of the housing. . As a result, it was found that the protruding length of the heat sink can be reduced because the temperature of the casing rises and the amount of heat released to the atmosphere increases.
In addition, it was confirmed from the evaluation result by the present Example 9 that it can be used even if the heat sink is removed.

(Example 10, Comparative Example 10)
Next, with respect to the projector 110 of the fourth embodiment shown in FIG. 20, the effect of heat radiation on the outer surface of the casing was examined (Example 10 and Comparative Example 10).
In the tenth embodiment, the projector 110 shown in FIG. 20 with the heat sink removed is used.
In addition, the inner and outer surfaces of the casing were black-coated (heat absorption rate α = 0.95, thermal emissivity ε = 0.95).
Each LED lamp was replaced with a resistor with the same calorific value, and the temperature was measured.
Furthermore, a thermocouple was attached to the housing surface, and the temperature of the housing surface was also measured. The measurement points are points P7-1, P7-2, P7-3, and point P8 shown in FIG. 23 (however, in this example, there is no heat sink and casing wire net part).
Point P7-1 is directly above the red LED, P7-2 is directly above the green LED, and P7-3 is directly above the blue LED. The point P8 is located above the lenses and far from the heat generating component.

The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The temperature at that time is shown in the embodiment of FIG.
In the table of FIG. 25, data is shown as a comparative example (Comparative Example 10) in which only the inner surface of the housing is painted black and the outer surface is aluminum metallic luster (ε = 0.055).
Note that Comparative Example 10 shown in the table of FIG. 25 has substantially the same conditions as Example 9 shown in the table of FIG.

As is apparent from the evaluation results of Example 10 and Comparative Example 10 shown in the table of FIG. 25, the amount of heat released from the housing to the atmosphere increases by applying black coating to the outer surface of the housing. It was found that the body temperature can be reduced and the temperature rise of each LED (substitute resistor) can be reduced.
Here, the upper limit temperature of each LED is 90 ° C. On the other hand, the LED is a semiconductor element whose luminance decreases and the wavelength shifts to the longer wavelength side as the temperature becomes higher.
Therefore, even if the heat dissipation state is designed so as not to exceed the LED upper limit temperature, the brightness of the projected image will decrease or the color balance will change until the LEDs reach the saturation temperature after the projector power is turned on. There were times when it shifted.
Therefore, the tenth embodiment has the advantage that the projector size is the same as that of the comparative example 10, but the projection image quality degradation after power-on is small.

[Seventh Embodiment]
Next, a seventh embodiment of the projector of the present invention will be described.
26 and 27 are diagrams showing a projector 170 according to the seventh embodiment, and this projector 170 is a modification of the projector 160 according to the sixth embodiment shown in FIG. . Components having the same functions as those of the fourth embodiment shown in FIGS. 11 and 12 and the sixth embodiment shown in FIG. 20 are denoted by the same reference numerals, and the description thereof is omitted or simplified. Turn into.

Similar to the sixth embodiment, the projector 170 has three transmissive liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate transmissive liquid crystal projector provided with a panel.
Similarly to the sixth embodiment, the projector 170 includes light sources (LED lamps) 111, 112, 113 corresponding to the R, G, and B lights, and the light sources 111, 112, 113, which are heat generating components. 113 and the housing 171 are thermally connected.
In addition, the code | symbol 172 shown in FIG. 27 is a drive circuit (liquid crystal drive circuit) of a light valve.

Further, unlike the sixth embodiment, the projector 170 has a configuration in which a heat sink as a heat radiator is removed.
That is, in this example, the housing 171 is a heat radiator, and the light sources 111, 112, 113 and the housing 171 are thermally connected via the heat transfer member 131. Accordingly, the metal mesh part of the housing in the sixth embodiment is omitted. As the material of the housing 171, a good heat conductor is preferably used. For example, in addition to an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof, copper, brass, gold, iron (and steel), nickel Various metals and alloys thereof are used.
Further, both the inner surface and the outer surface of the housing 171 are painted black, and the heat absorption rate and the heat emissivity of the inner surface and the outer surface of the housing 171 are about 0.95.

  Further, the housing 171 is provided with intake and exhaust openings (intake holes 173 and exhaust holes 174). In this example, the intake hole 173 and the exhaust hole 174 are formed on the side surface of the housing 171, and the exhaust hole 174 is disposed above the intake hole 173.

More specifically, the air intake hole 173 is formed on the side surface of the housing 171 disposed on the back side of the green light source 112 and is disposed below the base plate 175.
The exhaust hole 174 is formed on the side surface of the housing 171 facing the side surface on which the intake hole 173 is formed, and is disposed above the base plate 175.
With respect to the base plate 175, the air intake holes 173 are disposed below and the air exhaust holes 174 are disposed above, so that the light sources 111, 112, and 113, which are heat-generating components mounted on the base plate 175, have the air intake holes 173 in the vertical direction. And the exhaust hole 174, that is, above the intake hole 173 and below the exhaust hole 174.
In this example, the exhaust hole 174 is formed to have a larger opening area than the intake hole 173.

  The base plate 175 is provided with an opening (vent hole 176) in the vicinity of the light sources 111, 112, and 113. The vent hole 176 is preferably formed so that the opening area is as large as possible within the range of restrictions such as device arrangement and structure.

  With this configuration, in the projector 170 of this example, the air that flows in from the air intake hole 173 passes through the inside of the housing 171 through the vent hole 176, and takes the heat of the light sources 111, 112, and 113, which are heat generating components, and the air It is discharged from the exhaust hole 174. At this time, since the exhaust hole 174 is arranged above the intake hole 173, the air easily flows through the housing 171, such as warmed air is likely to rise. Therefore, heat exchange is effectively performed between the air and the heat generating components (light sources 111, 112, 113). Therefore, in this projector 170, the temperature rise of the heat generating component is suppressed, and the deterioration of the projected image is suppressed.

  In addition, since the opening area of the exhaust hole 174 is larger than the opening area of the intake hole 173, air is easily discharged from the housing 171 including the thermal expansion of air, and air and heat-generating components (light sources 111 and 112). , 113) is effectively exchanged heat.

  Furthermore, according to this configuration, since the heat generating components (light sources 111, 112, 113) are arranged between the intake hole 173 and the exhaust hole 174 in the vertical direction, these heat generating components are exhausted from the intake hole 173. It is arranged in the middle of the air flow up to the hole 174. Therefore, heat exchange is more effectively performed between the air and the heat generating component.

Here, FIG. 28 and FIG. 29 are views showing an example of the form of the intake hole 173 and the exhaust hole 174 of the housing 171, FIG. 28 is a perspective view, and FIG. 29 is a cross-sectional view.
28 and 29, the intake hole 173 and the exhaust hole 174 are formed by bending a part 171a toward the inside or the outside of the casing 171 after being cut into a part of the casing 171. .

As a result, the intake hole 173 and the exhaust hole 174 are substantially in a state where the flow path through which the air passes is bent, as shown in FIG. In this case, the opening area per one of the intake hole 173 and the exhaust hole 174 is given by approximately Loa × (2 × Lob + Loc).
In FIG. 29, reference numeral 171b denotes a shielding portion 171b disposed substantially parallel to the outer surface of the casing 171 in the bent portion 171a, and reference numeral 171c denotes an angle with respect to the outer surface of the casing 171 in the bent portion 171a. It is a flange part 171c arranged vertically.

  According to this configuration, since the flow paths of the intake holes 173 and the exhaust holes 174 of the housing 171 are bent, entry of foreign matter into the housing 171 is prevented. When the bent portion 171a is arranged inside the housing 171, the formation of protrusions on the outer surface of the housing 171 is avoided, and there is little possibility that a problem such as an electrical wiring being caught on the housing occurs. Become.

30, 31, and 32 are views showing examples of arrangement of the intake holes 173 and the exhaust holes 174 having the shapes shown in FIGS. 28 and 29, (a) is a perspective view, and (b) is a cross-sectional view. It is.
Further, in any of FIGS. 30A, 31A, and 32A, the front side of the paper is the inside of the housing, and the back side of the paper is the outside of the housing.

In the example shown in FIG. 30, the shielding part 171b of the bent part 171a is arranged extending in the vertical direction, and the flange part 171c is arranged on the lower side in the vertical direction with respect to the shielding part 171b.
In this case, in the opening part (intake hole 173, exhaust hole 174) of the casing 171, there is a vertically upward channel in the direction from the outside to the inside of the casing 171, and a vertically downward channel in the direction from the inside to the outside. It is formed.

In the example shown in FIG. 31, the shielding part 171b of the bent part 171a is arranged extending in the vertical direction, and the flange part 171c is arranged on the upper side in the vertical direction with respect to the shielding part 171b.
In this case, the opening part (intake hole 173, exhaust hole 174) of the casing 171 has a vertically downward channel in the direction from the outside to the inside of the casing 171 and a vertically upward channel in the direction from the inside to the outside. It is formed.

In the example shown in FIG. 32, the shielding portion 171b of the bent portion 171a is arranged extending in the horizontal direction, and the flange portion 171c is arranged facing the horizontal direction.
In this case, in the flow path in the opening portion (the intake hole 173 and the exhaust hole 174) of the housing 171, there is no portion that becomes a resistance in the vertical direction.

  Which of the states shown in FIGS. 30 to 32 is set for the intake hole 173 and the exhaust hole 174 is preferably determined based on the air flow direction. For example, by setting the intake hole 173 to the state shown in FIG. 30 or FIG. 32 and the exhaust hole 174 to the state shown in FIG. 31 or FIG. 32, the influence of the flange 171c on the rising air flow is avoided. The increase in resistance in the intake hole 173 and the exhaust hole 174 is suppressed.

(Example 11)
Next, with respect to the projector 170 of the seventh embodiment shown in FIGS. 26 and 27, the effects of the intake and exhaust holes of the casing were examined (Example 11, Comparative Example 11 (11a to 11e)).
In Example 11, the intake holes and exhaust holes formed in the housing are as follows.
(1) Two or more ventilation holes are provided in the housing, one is located above (exhaust hole) and the other is located below (intake hole). (2) The opening area of the exhaust hole is larger than the intake hole (opening (The area is the total opening area of the holes through which air passes.) (3) Heat generation in the area surrounding the vertical position of the intake hole—the vertical position of the exhaust hole and the horizontal position of the intake hole—the horizontal position of the exhaust hole Parts (each LED lamp) are arranged.

As shown in FIG. 27, the projector is installed such that the lens barrel (lens barrel) is tilted upward and the image is projected (projected) obliquely upward with respect to the projector (desktop installation / floor installation) (implementation). Example 11).
At this time, as shown by arrows in FIG. 27, the air flow is as follows: (1) Room temperature air enters the housing through the intake holes; (2) Air passes through the vent holes opened in the base plate. Reach the LED lamp, (3) each LED lamp, the air warmed by heat dissipation from the heat transfer member, etc. rises, (4) the warmed air rises along the inner wall of the upper surface of the housing, (5) exhaust hole The air was discharged out of the housing via

Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The measurement result of the temperature at that time is shown in Example 11 in the table of FIG. In the table of FIG. 33, the opening areas of the intake holes and the exhaust holes are also shown.

(Comparative Example 11a)
About the form which does not provide a ventilation hole (intake hole, exhaust hole) in a housing | casing, temperature was measured like Example 11 (comparative example 11a). The measurement results are shown in Comparative Example 11a in the table of FIG.

(Comparative Example 11b)
About the form which provided only the inlet hole in the housing | casing and did not provide an exhaust hole, temperature was measured like Example 11 (comparative example 11b). The measurement results are shown in Comparative Example 11b in the table of FIG. When only the intake holes are provided, the passage of the rising wind is difficult to form, so that warmed air tends to stay. As a result, the cooling effect is small and the temperature drop of the heat generating component is small.

(Comparative Example 11c)
About the form which provided only the exhaust hole in the housing | casing and did not provide an intake hole, temperature was measured like Example 11 (comparative example 11c). The measurement results are shown in Comparative Example 11c in the table of FIG. When only the exhaust hole is provided, since the passage of the wind is difficult to form, the cooling effect is small, so the temperature drop of the heat generating component is small.

(Comparative Example 11d)
An intake hole and an exhaust hole were provided in the housing, and the temperature was measured in the same manner as in Example 11 (Comparative Example 11d) for an embodiment in which the intake hole opening area> the exhaust hole opening area. The measurement results are shown in Comparative Example 11d in the table of FIG. If the opening area of the intake hole is larger than the opening area of the exhaust hole, as the warmed air tries to expand and the pressure increases, the air pressure in the vicinity of the exhaust hole increases and tries to push back the flow of air flowing in from the intake hole. As a result, the flow rate of the air flow inside the housing is reduced. Therefore, the cooling efficiency is reduced, and the temperature drop of the heat generating component is reduced.

(Comparative Example 11e)
As shown in FIG. 34, the temperature was measured in the same manner as in Example 11 with respect to an embodiment in which both the intake holes and the exhaust holes were provided above the heat generating component (Comparative Example 11e). The temperature at that time is shown in Comparative Example 11e in the table of FIG. In this embodiment, the heat generating component (each LED lamp) is located outside the area surrounded by the intake hole vertical position−exhaust hole vertical position and the intake hole horizontal position−exhaust hole horizontal position.
Therefore, as shown by the arrows in FIG. 34, the flow of the air heated by each LED lamp rises and the flow of the room temperature air drawn downward from the intake holes interferes with each other. The flow rate decreases.
That is, since the heat-generating component is not arranged in the range of the wind path where the heated air from the intake hole to the exhaust hole continues to rise, the flow rate of the air flow inside the housing is reduced.
As a result, the cooling efficiency is reduced and the temperature drop of the heat generating component is reduced.

  As is apparent from the evaluation results of Example 11 and Comparative Example 11 (11a to 11e) shown in the table of FIG. 33, air is generated by arranging heat-generating components between the intake holes and the exhaust holes in the vertical direction. It was found that heat exchange was effectively performed between the heat generating component and the temperature increase of the heat generating component.

(Example 12)
Next, regarding the projector 170 of the seventh embodiment shown in FIGS. 26 and 27, the effects of the shape and arrangement of the intake and exhaust holes of the housing shown in FIGS. 28 to 32 were examined (Example 12). (12a, 12b), Comparative Example 12).

Example 12a
In the housing, the intake holes were formed in the state shown in FIG. 30, and the exhaust holes were formed in the state shown in FIG. 31 (Example 12a).
Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The temperature measurement results at that time are shown in the table of FIG.

(Example 12b)
Both the intake hole and the exhaust hole were formed in the casing in the state shown in FIG. 32 (Example 12b). The temperature was measured in the same manner as in Example 12a. The measurement results are shown in Example 12b in the table of FIG.

(Comparative Example 12)
The intake holes are formed in the state shown in FIG. 31 and the exhaust holes are formed in the state shown in FIG. 31 (Comparative Example 12). The temperature was measured in the same manner as in Example 12a. The measurement results are shown in Comparative Example 12 in the table of FIG.

As is apparent from the evaluation results of Examples 12a and 12b and Comparative Example 12 shown in the table of FIG. 35, bent ventilation holes are provided on the side of the housing, the intake holes are directed inward from the outside, and the exhaust holes are inward. By setting the outward direction from the upper side, the eaves portion does not hinder the flow in which the air heated in the casing rises. Alternatively, it is possible to prevent the upward airflow from being disturbed by providing the eaves portion along the vertical direction.
As a result, entry of foreign matter can be prevented and cooling efficiency does not decrease.

[Eighth Embodiment]
Next, an eighth embodiment of the projector of the present invention will be described.
FIG. 36 is a diagram showing a projector 180 according to the eighth embodiment, and this projector 180 is a modification of the projector 170 according to the seventh embodiment shown in FIGS. 26 and 27. . Components having the same functions as those of the seventh embodiment shown in FIGS. 26 and 27 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

Similar to the seventh embodiment, the projector 180 has three transmissive liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate transmissive liquid crystal projector provided with a panel.
Similarly to the seventh embodiment, the projector 180 includes light sources (LED lamps) 111, 112, and 113 corresponding to the R, G, and B lights, and these light sources 111 and 112 that are heat generating components. 113 and the housing 181 are thermally connected.
Further, in the projector 180, the casing 181 is a heat radiator, the casing 181 is made of a good heat conductor such as aluminum, and the light sources 111, 112, 113 and the casing 181 provide the heat transfer member 131. Is connected thermally through.
Moreover, black coating is given to both the inner surface and the outer surface of the housing | casing 181, and the heat absorption rate and heat emissivity of the inner surface and the outer surface of the housing | casing 181 are about 0.95.
Further, the casing 181 is formed with intake and exhaust openings (intake holes 183 and exhaust holes 184), and the exhaust holes 184 are arranged above the intake holes 183.
The projector 180 of this example is different from the seventh embodiment in that an exhaust hole 184 is formed on the upper surface of the housing 181.

In other words, the exhaust hole 184 is formed on a surface that is arranged upward in the vertical direction when the projector 180 is used, and in this example, is formed in a substantially central portion of the upper surface.
As in the seventh embodiment, the intake hole 183 is formed on the side surface of the housing 181 and is disposed below the base plate 175 on which the light sources 111, 112, and 113, which are heat generating components, are mounted. ing.

FIG. 38 shows a form example of the exhaust hole 184.
30 to 32, the exhaust hole 184 is cut into a part of the casing 181 and then a part thereof (the bent part 181a) is placed inside or outside the casing 181. It is formed by bending toward the inside (in this example). In the example shown in FIG. 38, the shielding portion 181b of the bent portion 181a is arranged extending in the horizontal direction, and the flange portion 181c is arranged facing the horizontal direction.
Note that the intake hole 183 has, for example, the same form as in FIG.

  With this configuration, in the projector 180 of the present example, the exhaust hole 184 is provided on the upper surface of the casing 181, so that the air in the casing 181 is exhausted even when the projector is arranged obliquely during use. It is reliably discharged from 184. 36 shows a state where the projector 180 is installed so that the projection direction is obliquely downward (ceiling installation / suspended installation), and FIG. 37 shows that the projector 180 is installed so that the projection direction is obliquely upward. Indicates the status (desktop installation / floor installation).

  Therefore, in the projector 180 of this example, heat exchange is effectively performed between the air and the heat generating components (light sources 111, 112, 113) without being greatly affected by the posture at the time of projection. Temperature rise is suppressed, and deterioration of the projected image is suppressed.

(Example 13)
Next, the effect of the exhaust holes was examined for the projector 180 of the eighth embodiment shown in FIGS. 36 and 37 (Example 13 (13a, 13b), Comparative Example 13 (13a, 13b)).

(Example 13a)
As shown in FIG. 36, the projector is installed such that the lens tube (lens barrel) is tilted downward and an image is projected (projected) obliquely downward with respect to the projector (ceiling installation / hanging installation). Example 13a).
At this time, as shown by the arrows in FIG. 36, the air flow is as follows: (1) Room temperature air enters the housing through the intake holes; (2) Air passes through the vent holes opened in the base plate. Reaches the LED lamp, (3) the warmed air by heat radiation from each LED lamp, heat transfer member, etc. rises, (4) the warmed air slightly falls along the inner wall of the upper surface of the housing, (5) the housing The air was discharged out of the housing through the exhaust hole on the upper surface of the body.

Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The measurement result of the temperature at that time is shown in Example 13a in the table of FIG. Note that the projection direction of the projector (the attitude of the projector) is also shown in the table of FIG.

As shown in the table of FIG. 39, in Example 13a, the saturation temperature of the heat-generating component (substitute resistance of each LED) is slightly higher than in Example 11 shown in FIG.
This is because the flow rate of the air flow inside the housing is slightly reduced due to the influence of the air flow explanation (4) above, resulting in a decrease in cooling efficiency (heat exchange efficiency) and a decrease in the temperature of the heat generating component. This is because it has become smaller.

(Example 13b)
Next, as shown in FIG. 37, the projector was installed such that the lens barrel (lens barrel) is tilted upward and an image is projected (projected) obliquely upward with respect to the projector (desktop installation / floor installation) ( Example 13b).
At this time, as shown by the arrows in FIG. 37, (6) room temperature air enters the inside of the housing through the intake holes, and (7) air passes through the vent holes opened in the base plate. Reaches the LED lamp, (8) each LED lamp, the air heated by heat dissipation from the heat transfer member rises, (9) the warmed air rises along the inner wall of the upper surface of the housing, (10) the housing Air was discharged out of the casing through the exhaust hole on the top surface.

Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The measurement result of the temperature at that time is shown in Example 13b in the table of FIG.

In Example 13b, the above-described “Description (4)” state of the air flow in Example 13a was changed to the “Description (9)” state, so that the flow rate of the air flow inside the housing increased. .
Therefore, in Example 13b, as shown in the table of FIG. 39, the saturation temperature of the heat-generating component (replacement resistance of each LED) was the same as that of Example 11 shown in FIG.
That is, in Example 13b, the cooling efficiency (heat exchange efficiency) and the temperature drop of the heat-generating component (substitute resistance of each LED) were the same as those in Example 11.

(Comparative Examples 13a and 13b)
Next, as shown in FIG. 40, the projector according to the seventh embodiment shown in FIGS. 26 and 27 is tilted downward and the image is displayed obliquely downward with respect to the projector. It installed so that it might project (projection) (ceiling installation and hanging installation) (comparative example 13a). Note that the attitude of the projector is the same as that in Example 13a.
At this time, as shown by the arrows in FIG. 40, the air flow is as follows: (11) Room temperature air enters the housing through the intake holes; (12) Air passes through the vent holes opened in the base plate. Reaches the LED lamp, (13) each LED lamp, the air heated by heat dissipation from the heat transfer member, etc. rises, (14) the warmed air is located along the inner wall of the upper surface of the housing (15) Air is discharged to the outside through the exhaust holes on the side of the housing.

Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The measurement result of the temperature at that time is shown in Comparative Example 13a in the table of FIG.
A case where the projector of Comparative Example 13a is installed upward (that is, the same conditions as in Example 11 above) is shown in Comparative Example 13b of the table of FIG.

When the projector is installed face down, the temperature of the heat generating component (substitute resistor of each LED) of Comparative Example 13a is higher than that of Example 13a.
This is because the above-described wind flow “Explanation (14)” has to be warmed down for a longer distance than “Explanation (4)”. That is, the flow rate of the air flow inside the housing is smaller in “Description (14)” than in “Description (4)”. As a result, the cooling efficiency is decreased, and the temperature drop of the heat generating component is smaller in “Description (14)” than in “Description (4)”.

As is apparent from the evaluation results of Examples 13a and 13b and Comparative Examples 13a and 13b shown in the table of FIG. 39, the temperature of the heat generating component (substitute resistance of each LED) is
Example 13b (Upward) = Comparative Example 13b (Upward) <Example 13a (Downward) <Comparative Example 13a (Downward)
Therefore, it has been found that by providing the exhaust hole on the upper surface of the housing, it is possible to reduce the fluctuation of the heat dissipation efficiency of the heat-generating component when the orientation of the projector is changed.
For example, even when the projector is hung from the ceiling, it is possible to reduce the temperature rise of the heat-generating component, thereby reducing the brightness and color balance.

[Ninth Embodiment]
Next, a ninth embodiment of the projector of the present invention will be described.
41 and 42 are diagrams showing a projector 190 according to the ninth embodiment, and this projector 190 is a modification of the projector 190 according to the eighth embodiment shown in FIG. . Components having the same functions as those of the eighth embodiment shown in FIG. 36 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

As in the eighth embodiment, the projector 190 has three transmissive liquid crystals corresponding to three colors of R (red), G (green), and B (blue) as light modulation means (light valves). A three-plate transmissive liquid crystal projector provided with a panel.
Similarly to the ninth embodiment, the projector 190 includes light sources (LED lamps) 111, 112, and 113 corresponding to R, G, and B lights, and these light sources 111 and 112 that are heat-generating components. , 113 and a housing 191 made of a good heat conductor such as aluminum are thermally connected.
Moreover, black coating is given to both the inner surface and the outer surface of the housing | casing 181, and the heat absorption rate and heat emissivity of the inner surface and the outer surface of the housing | casing 181 are about 0.95.
The projector 190 of this example is different from the eighth embodiment in that a plurality of exhaust holes 194, 195, 196 are formed on the upper surface of the casing 191, and at least one of them is substantially true of the light sources 111, 112, 113. It is a point located above.

In this example, the exhaust holes 194, 195, 196 are arranged on the top surface of the housing 191 so that the exhaust hole 194 is located almost directly above the light source 111, the exhaust hole 195 is located almost directly above the light source 112, and the exhaust hole 196 is located directly above the light source 113. Is formed.
As in the eighth embodiment, the air intake hole 193 is formed on the side surface of the housing 191 and is arranged below the base plate 175 on which the light sources 111, 112, and 113, which are heat generating components, are mounted. ing.

  With this configuration, in the projector 190 of this example, the exhaust holes 194, 195, 196 are provided almost directly above the heat generating components (the light sources 111, 112, 113). Even if it exists, the air in the housing | casing 181 is discharged | emitted from the exhaust hole 184 more reliably. 42 shows a state where the projector 190 is installed so that the projection direction is obliquely downward (ceiling installation / suspended installation), and FIG. 43 shows that the projector 190 is installed so that the projection direction is obliquely upward. Indicates the status (desktop installation / floor installation).

  In the projector 190, heat exchange between the air and the heat generating components (light sources 111, 112, and 113) is more reliably performed without being greatly affected by the posture at the time of projection, thereby suppressing the temperature rise of the heat generating components. Thus, the deterioration of the projected image is more reliably suppressed.

(Examples 13c and 13d)
Next, the effect of the exhaust holes on the projector 190 of the ninth embodiment shown in FIGS. 41 to 43 was examined (Examples 13c and 13d).
As shown in Fig. 42, the projector with an exhaust hole directly above the heat generating component (each LED lamp) tilts the lens barrel (lens barrel) downward and projects an image obliquely downward with respect to the projector. (Projection) (ceiling installation / hanging installation) (Example 13c).
Similarly, as shown in FIG. 43, the projector with the exhaust hole provided directly above the heat generating component (each LED lamp) is tilted upward with the lens barrel (lens barrel) tilted upwardly with respect to the projector. (Projection) (desktop installation / floor installation) (Example 13d).

  At this time, in Example 13c and Example 13d, as shown by the arrows in FIG. 42 or FIG. 43, the air flow is (16) room temperature air enters the inside of the housing through the intake holes. Air passes through the vents in the base plate and reaches each LED lamp. (18) The air warmed by heat dissipation from each LED lamp, heat transfer member, etc. rises. (19) The updraft is unimpeded. It reached the exhaust hole on the upper surface of the housing and was discharged through the exhaust hole.

Next, each LED lamp was replaced with a resistor having the same calorific value, and the temperature of the resistor was measured.
The temperature rise reached saturation 30 minutes after power-on at an ambient temperature of 35 ° C. The temperature at that time is shown in Example 13c and Example 13d in the table of FIG.

  As is clear from the evaluation results of Examples 13c and 13d, and Examples 13a and 13b and Comparative Examples 13a and 13b described above, shown in the table of FIG. It was found that the effect on the heat dissipation efficiency of the heat-generating component due to the orientation of the projector in use can be eliminated by providing it directly above.

(Example 14, comparative example 14)
Next, the quality of the projected image was examined for the projector 190 of the ninth embodiment shown in FIGS. 41 to 43 (Example 14). The intake holes have the form shown in FIG. 30 and the exhaust holes have the form shown in FIG.
Further, the image quality of the projector 190 of the ninth embodiment was examined in the same manner for the form in which (a) the casing was not black-painted and (b) the intake and exhaust holes were omitted (comparative example) 14).
The saturation temperature of each LED lamp in Example 14 was 74 ° C., and the saturation temperature of each LED lamp in Comparative Example 14 was 90 ° C.
However, since this data is for an environmental temperature of 35 ° C., it is necessary for the subject to comfortably judge the image quality, so the image quality was evaluated at room temperature of 20-25 ° C.
The image quality evaluation method is as follows.

(Image quality evaluation method)
(A) About 50 men and women from 18 to 60 years of age were selected as subjects and their sex was randomly selected.
(B) There are four types of evaluated projected images: still images composed of characters and graphs, landscape still images, animated moving images, and live-action moving images.
(C) The room brightness is 30 lux (brightness of the moon), 70 lux (lighting standards for miscellaneous work under the Labor Standards Act), 150 lux (normal work), 300 lux (precision work), 1000 lux (precision) 5 standard of work recommended standards).
(D) Have a five-step evaluation until the color balance is not visible or clearly out of color, and average the average of 5 to 4 (symbol ○). Slightly poor (symbol Δ), less than 3 was determined to be defective (symbol ×).

(Image quality evaluation results)
The image quality evaluation results are shown in the table of FIG.
As is apparent from the table shown in FIG. 44, it was found that Example 14 can project a live-action moving image well at an indoor brightness of 30 lux to 1000 lux.
In addition, it was found that Comparative Example 14 can be used up to a live-action moving image when the room brightness is 30 lux. Also, up to 150 lux in the room, it was possible to use up to still images, although there was some image quality degradation. It is sufficient for at least a character still image, that is, a business presentation.
In other words, by promoting heat exchange between air and heat-generating parts, and reducing the temperature rise of the heat-generating parts (each LED lamp), the decrease in brightness and color balance are reduced. It was also found that images with a more natural shape can be projected with high image quality.

[Tenth embodiment]
Next, a tenth embodiment of the projector according to the present invention will be described.
45 and 46 are diagrams showing a projector 200 according to a tenth embodiment. This projector 200 has a single-plate transmission type that includes one transmission type liquid crystal panel as a light modulation means (light valve). It is a liquid crystal projector.
The projector 200 includes a light source 201, a horn type reflector 202, a light valve (transmission type liquid crystal panel) 203, a projection system 204, and the like.

  As the light source 201, an LED light source (LED lamp) including an LED (light emitting diode, organic electroluminescent element) as a light emitting element is used.

  Light from the light source 201 passes through the reflector 202 and enters the light valve 203. The light valve 203 includes, for example, a thin film transistor (TFT) as a switching element and a transmissive liquid crystal cell, and modulates light from the light source 201 based on image information (or video information) from the outside. The projection system 204 includes an enlarged projection optical system, and projects the light emitted from the light valve 203 onto a screen (not shown). By this projection, an enlarged image is displayed on the screen. In addition, an LED lamp that emits white light is used as the light source 201, and a color filter in which micro filters of red (R), green (G), and blue (B) are arranged is installed in the light valve 203 (liquid crystal panel). A color image can be obtained.

The projector 200 also includes a heat sink 210 for radiating heat from the light source 201 that is a heat generating component, and a heat transfer member 211 that thermally connects the light source 201 and the heat sink 210.
The power supply circuit (power supply unit) is arranged separately from the main body.

  As the heat transfer member 211, a good heat conductor is preferably used. In this example, an aluminum material (thermal conductivity: 206 W / (mK)) or an alloy thereof is used. In addition, as the heat transfer member, various metals such as copper, brass, gold, iron (and steel), nickel, and alloys thereof may be used. The heat transfer member 211 is also mounted with a light valve drive circuit (liquid crystal drive circuit), but is not shown.

  In this example, the heat sink 210 is provided with a plurality of plate-like fins. Note that the heat sink is not limited to a form having a plurality of plate-like fins, but may have another form. Moreover, it may replace with a heat sink and you may use another thermal radiation means (for example, cooling fin). Since the heat sink does not have a drive mechanism, there is an advantage that it is easy to reduce the size.

Further, the heat sink 210 has a larger surface area in a portion closer to the light source 201 which is a heat generating component.
That is, in this example, the direction away from the light source 201 and the axial direction of the reflector 202 coincide with each other, and the heat sink 210 has a larger surface area closer to the light source 201 along the axial direction of the reflector 202 and a farther part. The surface area is reduced.

  In the heat sink 210, since the amount of heat passing through the portion closer to the heat generating component (light source 201) is larger, the heat radiation efficiency is improved by forming a larger surface area of the portion. Further, in the heat sink 210, the amount of heat passing therethrough is relatively small in a portion away from the heat generating component (light source 201), so that the surface area of the portion is formed small, so that the shape is optimized and the volume is increased. It can be kept small. Thereby, in the projector 200 of this example, the size of the apparatus can be reduced.

  In the projector 200 described above, the surface area of the heat sink for each portion is changed by changing the overall shape of the heat sink, but the present invention is not limited to this. That is, for each portion, the surface area of the heat sink may be changed by changing the arrangement density of the plurality of fins or changing the shape of the fins.

(Example 15)
Next, the effect of the heat countermeasure technique was examined for the projector 200 of the tenth embodiment shown in FIGS. 45 and 46 (Example 15).
In the following description, the unit of dimensions in the drawings is “mm”.

As the LED lamp, Luxeon series manufactured by LumiLeds, AB07-White (white), and power consumption 5 W were used. As the heat sink, UB35-25B manufactured by α Co. was used.
45 and 46, point P1: a light emitting part (heat generating part) of a heat generating component (LED lamp), point P2: a point closest to the heat generating part of the heat sink, point P3: a thermoelectric point farthest from the heat generating part of the heat sink A pair was attached and the temperature was measured.
The upper limit temperature of the LED lamp is 90 ° C, and if it exceeds this temperature, it will be damaged or its life will be shortened, so a resistor of 28.8Ω (0.42A at 12V, that is, 5W heat) (Nikon Corp. power metal) Film resistance RNP-5 type with heat sink connection structure) was used as a heat generating component instead of a lamp.
In addition, the unit was placed in a 1 m square transparent acrylic resin box so that the influence of wind from the outside was removed and the atmosphere would be natural convection. The ambient temperature was kept at 35 ° C using a constant temperature room.
The temperature rise reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in Example 15 in the table of FIG. The table in FIG. 47 also shows the area of the bottom surface on which the heat sink blades (fins) are arranged. This bottom area is proportional to the total surface area of fins of the heat sink (area of heat transfer surface / heat dissipation surface).

(Comparative Example 15)
FIG. 48 shows a projector as a comparative example.
The projector shown in FIG. 48 (Comparative Example 15) has a constant heat sink surface area regardless of the distance from the heat-generating component (light source (LED lamp)) as compared to the projector shown in FIGS. 45 and 46 (Example 15). It is a thing. Other configurations are the same as those of the projector shown in FIGS.
In addition, the surface area of the whole heat sink is the same between Example 15 and Comparative Example 15.
The same LED lamp as in Example 15 was used.

A resistor is installed in place of the LED lamp as a heat generating component. Point P4: Light emitting part (heat generating part) of the heat generating component (LED lamp), point P5: Closest to the heat generating part of the heat sink, point P6: Heat sink A thermocouple was attached to the place farthest from the heat generating part, and the temperature was measured. The measurement method is the same as in Example 15.
The temperature rise reached saturation 30 minutes after the power was turned on. The temperature at that time is shown in Comparative Example 15a in the table of FIG.
In addition, from the table of FIG. 47, the temperature of the heat generating point P4 has exceeded the upper limit of 90 ° C., so increasing the length of L1 increases the heat sink bottom area (proportional to the surface area) to increase the temperature. Was measured. The measurement results are shown in Comparative Examples 15b and 15c in the table of FIG.

  As is clear from the evaluation results of Example 15 and Comparative Example 15 shown in the table of FIG. 47, the heat sink heat sink efficiency is improved by forming a larger surface area closer to the heat-generating component. As a result, it was found that the bottom area of the heat sink (proportional to the overall surface area of the heat sink, that is, proportional to the overall size) can be reduced, and the projector main unit can be reduced in size.

  The preferred embodiments according to the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

The figure for demonstrating the thermal resistance of a heat-transfer member. FIG. 2 is a diagram schematically illustrating a schematic overall configuration of the projector according to the first embodiment. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector of FIG. FIG. 5 is a configuration diagram of a projector according to Comparative Example 1. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 2nd Embodiment. The layout of a power supply unit. FIG. 6 is a configuration diagram of a projector according to Comparative Example 2. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 3rd Embodiment. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and the heat sink protrusion length. FIG. 10 is a configuration diagram of a projector according to Comparative Example 3. The figure which shows typically the schematic whole structure of the projector which concerns on 4th Embodiment. It is a top view which shows typically the mode of arrangement | positioning of each structural member in the projector 110 of FIG. The figure which shows the arrangement | positioning state of a heat sink. The state of arrangement | positioning of each component of the projector which concerns on the comparative example 4 is shown. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and the bottom area (surface area) of a heat sink. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and the bottom area (surface area) of a heat sink. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 5th Embodiment. The figure which shows the result of having measured the temperature of the projector. FIG. 10 is a configuration diagram of a projector according to Comparative Example 7. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 6th Embodiment. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and the heat sink protrusion length. FIG. 10 is a configuration diagram of a projector according to Comparative Example 8. The figure which shows the measurement location of temperature. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and a housing | casing, and heat sink protrusion length. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and a housing | casing, and heat sink protrusion length. The top view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 7th Embodiment. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 7th Embodiment. The perspective view which shows an example of the form of an inlet hole and an exhaust hole. Sectional drawing which shows an example of the form of an inlet hole and an exhaust hole. The figure which shows the example of arrangement | positioning of an intake hole and an exhaust hole. The figure which shows the example of arrangement | positioning of an intake hole and an exhaust hole. The figure which shows the example of arrangement | positioning of an intake hole and an exhaust hole. The figure which shows the result of having investigated the relationship between the temperature of a heat-emitting component and the opening area of the inlet hole and exhaust hole of a housing | casing. The block diagram of the projector which concerns on the comparative example 11e. The figure which shows the result of having measured the temperature of the heat-emitting component. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 8th Embodiment. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 8th Embodiment. The figure which shows the example of a form of an exhaust hole. The figure which shows the result of having measured the temperature of the heat-emitting component. The block diagram of the projector which concerns on the comparative example 13a. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 9th Embodiment. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 9th Embodiment. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 9th Embodiment. The figure which shows the evaluation result of an image quality. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 10th Embodiment. The side view which shows typically the mode of arrangement | positioning of each structural member in the projector which concerns on 10th Embodiment. The figure which shows the result of having measured the temperature of the heat sink. FIG. 18 is a configuration diagram of a projector according to Comparative Example 15.

Explanation of symbols

  10, 40, 50, 110, 150, 160, 170, 180, 190, 200 ... projector, 11 ... light source (halogen lamp, heat generating component), 20, 21, 22 ... light valve (reflective liquid crystal panel, heat generating component) 31a ... transistor (heat generating component), 32, 44, 52, 125, 151, 161, 210 ... heat sink (heat radiator), 33, 43, 131, 211 ... heat transfer member, 41 ... power supply unit (heat generating component), 51, 162, 171, 181, 191 ... casing, 111, 112, 113, 201 ... light source (LED lamp, heat generating component), 114, 115, 116, 203 ... light valve (transmission type liquid crystal panel), 127, 173 , 183, 193 ... intake holes, 128, 174, 184, 194 ... exhaust holes.

Claims (8)

A plurality of heat generating components;
A radiator,
A heat transfer member that thermally connects the plurality of heat generating components and the heat dissipating member;
A housing that covers the plurality of heat generating components,
The plurality of heat generating components have a shorter thermal distance on the heat transfer member up to the heat radiator in descending order of heat generation,
The plurality of heat generating components and the housing are thermally connected,
The housing is provided with an intake hole and an exhaust hole disposed above the intake hole,
The intake hole and the exhaust hole are
A plurality of openings provided on one surface of the housing;
A plurality of members respectively disposed in the plurality of openings, a shielding portion disposed in parallel with one surface of the casing provided with the openings, and a flange portion disposed obliquely or perpendicularly to the one surface And the plurality of members each having
Possess a plurality of bent flow path formed along the shield portion and the overhanging portion of the plurality of members, and
The heat transfer member is made of a metal or alloy having a predetermined thermal conductivity, to have a shape that is designed with a predetermined thermal conductivity so as to suppress the volume of the heat transfer member, characterized in that Projector. Each of the intake hole and the exhaust hole is provided on a side surface of the housing,
The projector according to claim 1, wherein the plurality of members are arranged inside or outside the casing. The plurality of members are arranged inside the housing,
In the intake hole, the shielding portion extends in the vertical direction, and the flange portion is disposed below the vertical direction with respect to the shielding portion,
3. The exhaust port according to claim 2, wherein the shielding portion extends in the vertical direction and the flange portion is disposed on the upper side in the vertical direction with respect to the shielding portion. projector. The plurality of members are arranged inside the housing,
In each of the intake hole and the exhaust hole, the shielding part extends in the horizontal direction, and the flange part is arranged in the horizontal direction with respect to the shielding part. The projector according to claim 2.   The projector according to claim 1, wherein the exhaust hole is provided on an upper surface of the casing.   The plurality of members are each formed by cutting a part of the casing and then bending the part toward the inside or the outside of the casing. The projector according to claim 5.   7. The total opening area of the plurality of openings in the exhaust hole is larger than the total opening area of the plurality of openings in the intake hole. 8. Projector. Wherein the plurality of heat generating components, claim vertically with respect disposed between the intake hole and the exhaust hole, and disposed between said air intake hole in the horizontal direction and the exhaust hole, characterized in Rukoto 1 The projector according to claim 7.

Images