KR20030025343A - Projection display device - Google Patents

Abstract

PURPOSE: A projection display device is provided to achieve improved reliability and reduce manufacturing costs by improving the cooling structure to be capable of cooling the image reproducing unit and driving circuit unit at the same time. CONSTITUTION: A projection display device(50) comprises a first optical unit(73) disposed at the optical path formed between a light source(71) and a display element(77); a second optical unit(75) disposed at the optical path formed between the display element and a screen; a driving circuit unit(60) for driving and controlling first and second optical units and the display element; a cooling fan(81) for compulsorily blowing air to the display element; a pair of guide members(83) for guiding the air blown from the cooling fan to the display element and to the first optical unit and the driving circuit unit; and a heat radiation member coupled to the display element, and which absorbs heat generated from the display element and is compulsorily cooled by the cooling fan. The heat radiation member guides the air blown from the cooling fan to the first optical unit and the driving circuit unit.

Description

Projection display device {Projection display device}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display apparatus for enlarging and projecting an image formed by a display element, and more particularly, to a projection display apparatus employing a cooling device for cooling an image reproducing unit.

A typical projection display apparatus includes a main body with a screen formed on the outside, an image reproducing unit embedded in the main body to generate an image projected on the screen, and a driving circuit unit for driving and controlling the image reproducing unit.

The image reproduction unit includes a light source, a display element, a first optical unit disposed on an optical path between the light source and the display element, and a second optical unit disposed on an optical path between the display element and the screen. The apparatus further includes a cooling device for cooling the inside of the main body.

When the display element is driven, driving heat is generated, and when the driving heat is high, the image quality of the projected image is degraded. Therefore, conventionally, the cooling device is concentrated on the display element side.

1 shows, by way of example, one form of a chiller 20 commonly used to cool the display element 13. According to FIG. 1, the cooling device 20 includes at least one heat sink 22, 24 and a heat pipe 23. In order to improve the cooling effect of the display element 13, a thermoelectric element 21 (Peltier element) using the Peltier effect is provided between the display element 13 and the heat sink 22. The thermoelectric element 21 absorbs the driving heat of the display element 13 and then transfers the driving heat to the outer wall of the main body 10 connected through the heat pipe 23 and the heat sink 24. On the other hand, although not shown, in the cooling device 20, the heat pipe 23 may be omitted, and a cooling fan may be provided to forcibly blow external air to the heat sink 22.

2 illustrates a result of measuring a temperature distribution at each point along an optical path of an image reproducing unit (not shown).

As shown, in a typical projection display apparatus, the display element 13 is disposed at a position of about 300 mm based on a light source (not shown). At this time, the first optical unit (not shown) provided between the display element 13 and the light source has a higher temperature than the display element 13. On the other hand, although not shown, the second optical unit (not shown) provided between the display element 13 and the screen (not shown) has a lower temperature distribution than the display element 13.

In the conventional projection display device having the temperature gradient as described above, since the cooling device 20 is concentrated on the display element 13 side and does not properly cool the first optical part side, There is a problem that the cooling effect of the display element is lowered by the driving heat transmitted.

In addition, since the cooling device must be additionally installed to cool the first optical unit, manufacturing cost increases. In addition, in addition to the image reproducing unit, there is a problem that a separate cooling device must be further installed to cool the driving circuit unit generating a lot of heat in the main body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a projection display device having an improved cooling structure to simultaneously cool an image reproducing unit and a driving circuit unit in order to improve product reliability at a low manufacturing cost. .

1 is a cross-sectional view showing a cooling structure of a conventional projection display device.

2 is a view showing a temperature distribution of each point along an optical path of a conventional projection display device.

3 is a perspective view showing the inside of the projection display device according to the present invention;

Figure 4 is an enlarged perspective view of the extraction of the cooling device of FIG.

5 is a side cross-sectional view taken along the line A-A of FIG.

6A-6B show the flow rate distribution of air at each point along the X axis of FIG.

Explanation of symbols on the main parts of the drawings

50: projection display device 60: driving circuit unit

70: image reproduction unit 71: light source

73: first optical portion 75: second optical portion

77 display device 80 cooling device

81: cooling fan 83: guide member

85: heat sink 86: heat sink body

87: heat radiation fins 89: thermoelectric elements

An object of the present invention as described above, the first optical portion disposed on the optical path between the light source and the display element, the second optical portion and each optical portion and the display element disposed on the optical path between the display element and the screen And a driving circuit section for driving and controlling the cooling fan, and a pair of guides for guiding air from the cooling fan to the display element while guiding air from the cooling fan to the display element. It can be achieved by providing a projection display device including a member and a heat dissipation member coupled to the display element to absorb driving heat of the display element and forcibly cooled by the cooling fan.

The heat dissipation member may include a heat sink having a heat dissipation body coupled to the display element and a heat sink having a predetermined length protruding from the heat dissipation body toward the cooling fan, and having a plurality of heat dissipation fins formed in a plate shape. And it is preferable to be disposed in the X direction to send a lot of flow to the drive circuit portion.

The heat dissipation member may further include a thermoelectric element installed between the heat dissipation body and the display element.

The projection display device configured as described above can simultaneously cool the first optical unit and the driving circuit unit together with the display element with one cooling fan, thereby reducing the manufacturing cost and improving the overall reliability of the product.

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

FIG. 3 shows the inside of a projection display device 50 including an image reproducing unit 70 for reproducing an image as one display element 77. According to FIG. 3, the projection display device 50 shows an image reproduction. A main body 51 having the unit 70 and the driving circuit unit 60 therein, and a screen (not shown) provided on the main body 51 so that the image reproduced by the image reproducing unit 70 is projected.

The driving circuit unit 60 is for driving and controlling the projection display apparatus 50 including the image reproducing unit 70, and a predetermined electronic circuit is provided therein.

The image reproducing unit 70 includes a light source 71 and a display element 77, and guides the light emitted from the light source 71 to the display element 77 and at the same time corresponds to the light. A predetermined optical system for projecting the image reproduced at 77) onto the screen is provided.

The optical system includes a first optical unit 73 disposed between the light source 71 and the display element 77, and a second optical unit 75 disposed on an optical path between the display element 77 and the screen. And a plurality of lenses (not shown), reflectors 72, and polarizers (not shown). As the display element 77, various types of liquid crystal elements (LCDs) commonly used are used. Although the image reproducing unit 70 in the present embodiment is described using one display element 77 as an example, the configuration of the image reproducing unit 70 uses three display elements 77. Various configurations may be possible.

Meanwhile, the projection display device 50 configured as described above further includes a cooling device 80 for cooling the inside of the main body 51.

As shown in FIGS. 4 and 5, the cooling device 80 includes a cooling fan 81, a guide member 83, and a heat dissipation member.

The cooling fan 81 is installed on the main body 51 and performs a function of forcibly blowing air from the outside into the main body 51. The air blown into the main body 51 by the cooling fan 81 flows inside the main body 51, and after cooling each of the components, the outside of the main body 51 through an exhaust port (not shown) installed on the main body 51. To be discharged.

The heat dissipation member is for effectively cooling the display element 77 that influences the image quality of the image being reproduced, among the image reproducing units 70, and the heat dissipation member in this embodiment is a display element opposed to the cooling fan 81. A heat sink 85 is coupled to one surface of the 77. Here, the heat sink 85 is installed to face the cooling fan 81 in a state spaced apart by a predetermined distance.

5, the heat dissipation member further includes a thermoelectric element 89 disposed between the heat sink 85 and the display element 77 to improve the cooling effect of the display element 77. . The thermoelectric element 89 cools the display element 77 by using a Peltier effect. That is, when power is applied to the thermoelectric element 89, the thermoelectric element 89 absorbs the driving heat generated by the display element 77 through the contact surface with the display element 77, and the contact surface with the heat sink 85. Through the heat sink 85, the driving heat absorbed by the display element 77 is dissipated. The heat sink 85 which receives the driving heat of the display element 77 is cooled by the outside air blown by the cooling fan 81.

Here, the heat sink 85 includes a plurality of heat sinks 86 protruding from the heat sink body 86 coupled with the display element 77 with the thermoelectric elements 89 interposed therebetween, and a direction in which the cooling fan 81 is installed from the heat sink body 86. It includes a heat radiation fin (87). Here, the heat dissipation fins 87 form a predetermined pattern and protrude from the heat sink body 86, which will be described later.

The guide member 83 is for guiding the external air after blowing from the cooling fan 81 to cool the heat sink 85 to be directed toward the driving circuit unit 60 and the first optical unit 73. . In order to perform such a function, the guide member 83 is installed to isolate the upper and lower portions between the cooling fan 81 and the heat sink 85 so that the external air does not flow to the upper and lower portions of the heat sink 85. It is formed in a plate shape. Here, the guide member 83 is not limited to the present embodiment, and may be modified in various installation positions, directions, and shapes according to the installation positions of the driving circuit unit 60 and the first optical unit 73. . For example, although not shown, if the first optical unit 73 and the driving circuit unit 60 are located at a long distance from the cooling fan 81, the guide member 83 is formed in a duct shape so that external air may be supplied to the first optical unit. It may be guided to the portion 73 and the driving circuit portion (60).

As described above, in order to guide the air sucked by the cooling fan 81 to the first optical unit 73 and the driving circuit unit 60, the heat dissipation fins 87 of the heat sink 85 form a predetermined pattern, It is disposed on the body 86. Each of the heat dissipation fins 87 is formed in a plate shape, and are disposed at predetermined intervals to form an air flow path 88 through which air can flow between the heat dissipation fins 87. At this time, the air passage 88 is preferably formed to guide the air in the same direction as the direction of the air guided by the guide member 83, as shown by the arrow shown in FIG. In order to meet this demand, each of the heat dissipation fins 87 is arranged in parallel with the guide member 83.

The operation of the cooling device 80 of the projection display device 50 configured as described above is as follows.

When the cooling fan 81 is driven, external air is blown from the outside into the main body 51. The blown external air is directed to the heat sink 85 opposite the cooling fan 81, and the display element 77 is cooled as the heat sink 85 is cooled. The cooling effect of the display element 77 is improved by the thermoelectric element 89 further provided between the display element 77 and the heat sink 85.

After cooling the heat sink 85, the air is branched left and right by the air flow path 88 and the plurality of guide members 83 of the heat sink 85 to drive the circuit 60 and the first optical unit 73. Guided to the side. Accordingly, the driving circuit unit 60 and the first optical unit 73 may be cooled simultaneously.

Here, the directional heat sink 85 and the guide member 83 are for guiding the air blown from the cooling fan 81 to the first optical portion 73 and the drive circuit portion 60 without loss of flow rate, Effects of the installation of the directional heat sink 85 and the guide member 83 are as shown in FIGS. 6A and 6B.

FIG. 6A illustrates a result of measuring a change in flow velocity at each selected point while moving in the X-axis direction (see FIG. 3) in the projection display apparatus 50 in which the guide member 83 is mounted according to the present invention. 6B shows the result of measuring the change of the flow velocity in the same manner in the state where the guide member 83 is not installed. Here, each point at which the flow velocity is measured is selected by moving in the right direction of the main body 51 with respect to the left side of the main body 51 shown in FIG. 3. The flow velocity measured at each point was expressed as a positive value of the speed of air directed to the right direction of the main body 51 and a negative value of the air directed to the left direction of the main body 51.

As shown, the display element 77 and the cooling fan 81 are located at a point (0.2 m) at which the air flow rate is 0 kPa, and the right side of the cooling fan 81 flows in the right direction to increase the flow rate. A positive value is displayed. On the left side of the cooling fan 81, since the air flows in the left direction, the flow rate is displayed as a negative value.

At this time, the result after the guide member 83 is installed and the result before the guide member 83 are installed, the position (0.3-0.4m) where the first optical unit 73 is installed and the position where the driving circuit unit 60 is installed ( Comparing from 0 to 0.1 m), it can be seen that the flow velocity at the position within the above range in the state where the guide member 83 is installed is shown to be high on average. Considering that the flow rate of air and the flow rate of the introduced air are proportional to each other, the fins are directed by the heat sink 85 and the guide member 83 in the direction perpendicular to the heat sink 85 having the directivity. It will be appreciated that there is more flow rate reaching the first optical portion 73 and the drive circuit portion 60 side than when the guide member 83 is formed and the guide member 83 is not provided. Referring to these results, the first optical portion 73 and the driving circuit portion 60 without loss of flow rate of the external air introduced from the cooling fan 81 by the heat sink 85 and the guide member 83 having the directionality. ), It can be seen that the cooling efficiency of the first optical unit 73 and the driving circuit unit 60 is improved.

Meanwhile, in addition to the thermoelectric element 89 and the heat sink 85, various types of cooling devices may be further included to increase the cooling effect of the display element 77, and the cooling fan 81 may also be currently used. Of course, all of the various types of cooling fans 81 can be used.

According to the projection display apparatus 50 of the present invention configured as described above, the guide member 83 is further provided, and the structure of the heat dissipation member is changed, whereby the display element 77 and the first cooling fan 81 are formed. 1 The optical unit 73 and the driving circuit unit 60 can be cooled simultaneously.

Accordingly, temperature control of the first optical unit 73 and the driving circuit unit 60 together with the display element 77 can be performed, thereby improving the reliability of the product.

In addition, since only one cooling fan 81 can improve the cooling effect to the maximum, the manufacturing cost of the product is reduced.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. will be.

Claims (3)

A first optical unit disposed on an optical path between the light source and the display element, a second optical unit disposed on an optical path between the display element and the screen, and a drive for driving and controlling the respective optical unit and the display element In the projection display device having a circuit portion, A cooling fan for forcibly blowing air to the display element; A pair of guide members for guiding air from the cooling fan to the display element and simultaneously to the first optical portion and the driving circuit portion; And And a heat dissipation member coupled to the display element to absorb the driving heat of the display element, forcibly cooled by the cooling fan, and guide air of the cooling fan to the first optical unit and the driving circuit unit. A projection display device. The method of claim 1, wherein the heat dissipation member, A heat sink body coupled with the display element; And a heat sink having a plurality of heat dissipation fins protruding from the heat sink body toward the cooling fan at a predetermined length and formed in a plate shape. And the heat dissipation fins are disposed in parallel with the guide member to guide air in a direction parallel to the guide member. The method of claim 2, wherein the heat dissipation member, And a thermoelectric element disposed between the heat sink body and the display element.