KR20100049299A - Projection system and surface light source conversion device - Google Patents

Abstract

The projection system of the present invention includes: a white light emitter; A light tunnel placed in front of the white light emitter exiting side; A color wheel placed on the exit side of the light tunnel; A display element for mounting an image signal on the light transmitted through the color wheel; And a projection lens for projecting light emitted from the display element onto a screen. According to the present invention, the passage of the light is simplified, thereby reducing the possibility of failure in the optical path, and the optical path is simplified, which makes the manufacturing convenient, the number of parts is reduced, the manufacturing cost is reduced, and the cost of the projection system is low, but the durability This can be improved and contribute to the increase in the image quality and luminance of the projection system.

Description

Projection system and surface light source conversion device

The present invention relates to a projection system and a surface light source device.

A projection system is a device that loads an image signal onto light projected by a light emitting device and projects an image from a front or rear surface of a screen to view an image. These devices are provided with a light emitting device, for example, a surface light source device for converting light generated from a point light source such as a lamp or light emitting diode into a surface light source. The surface light source device is a device for providing an equivalent luminance to the entire area of the image given to 3: 4 or 16: 9.

As a representative example of a surface light source device and a projection system using the same, there is a publication No. 10-2006-0022588 filed by the present applicant. In the prior art, a technique is disclosed in which surface light is sourced by passing light generated from a light emitting diode by passing through a light tunnel the reflected and focused light using an ellipsoid mirror or a collimator. However, according to the related art, a separate space for installing an ellipsoid mirror or a collimator is required in the projection system, and a lot of space is required, and the number of parts thereof increases. In addition, since there is a lot of light leaking from the ellipsoid mirror or the collimator there is a problem that the utilization efficiency of the light itself is not high.

In view of the above problems, the present invention proposes a surface light source device and a projection system capable of miniaturizing and simplifying the structure, thereby achieving simplification of the optical path, convenience of design, reduction of manufacturing cost, and reduction of the number of parts. .

The projection system according to the present invention comprises: a white light emitter; A light tunnel placed in front of the white light emitter exiting side; A color wheel placed on the exit side of the light tunnel; A display element for mounting an image signal on the light transmitted through the color wheel; And a projection lens for projecting light emitted from the display element onto a screen. According to another aspect of the present invention, a projection system includes: at least two light emitters; A light tunnel placed in front of the exit side of each of the at least two light emitters; A prism placed on an exit side of the light tunnel to emit light in a single direction; A display element for mounting an image signal on the light passing through the prism; And a projection lens for projecting light emitted from the display element onto a screen. According to yet another aspect, a projection system of the present invention comprises: a light emitter; A light tunnel which is placed in front of the light emitter emitting side and directly receives the light emitted from the light emitter without reflection or condensing action between the light emitter; A display element for mounting an image signal on a surface light source passing through the light tunnel; And a projection lens for projecting light emitted from the display element onto a screen.

In each of the above-mentioned inventions, it is preferable that the area of the incident side of the light tunnel is larger than that of the exit side.

The surface light source device according to the present invention, the light emitting body; And a light tunnel in which the incidence side immediately lies on the emission side of the light emitter. Here, it is preferable that the incident area of the light tunnel is larger than that of the exit side.

According to the present invention, the passage of light is simplified, thereby reducing the possibility of failure in the optical path, and the optical path is simplified, which makes the manufacturing convenient, the number of parts is reduced, the manufacturing cost is reduced, the manufacturing process is easy, and the use efficiency of the light is reduced. This has a growing advantage.

Although the present invention may include various embodiments, the present invention is not limited to the following specific embodiments, and may include various embodiments and modifications according to various operation methods of the projection system.

<First Embodiment>

1 is a diagram for explaining a projection system according to a first embodiment.

Referring to Fig. 1, the projection system of the present embodiment is a light tunnel placed in front of the light emitting device 1 and the light emitting side of the light emitting device 1 in front of the light emitting device 1 so as to make the light emitted from the light emitting device 1 surface light. (2), a color wheel (3) placed on the exit side of the light tunnel (4), and a surface light emitted from the light tunnel (2) by being placed behind the color wheel (3). Condensing condensing lens 5, the digital micro mirror device (DMD) 6 for reflecting the surface light focused at the condensing lens 5 corresponding to the pixel, and the light reflected from the DMD 6 to the screen A projection lens 7 for projecting is included.

Between the condensing lens 5 and the DMD 6, other components for focusing light and adjusting the length of an optical path, such as a relay lens and a reflecting mirror, may be further placed.

Here, in the surface light source device which makes a point light source into a surface light source in a projection system, it corresponds to the light tunnel 2 which lies in front of the light emitting body 1 and the exit side of the light emitting body 1 on the light path. Subsequent parts on the optical path may be used in various ways depending on the specific type of projection system. For example, various modifications such as using a field lens on the incident side of the DMD 6, using a reflector on the incident side of the DMD 6, or using a prism may be possible. As such, when the surface light source device is provided with a light emitter and a light tunnel, an ellipsoid mirror or a collimator for focusing light, which has been conventionally provided, is not required. Therefore, by simplifying the light passage path, it is possible to reduce the possibility that a failure occurs in the projection system while passing through the light path, thereby reducing the manufacturing cost and manufacturing cost.

Each structure mentioned above is demonstrated in more detail.

The light emitting device 1 may be a light emitting diode (LED) or a small size lamp mounted on a predetermined mounting mechanism. The light emitting device 1 is a white light source, and is separated into three colors of red green blue inside the projection system. Preferably a white light emitting diode is used.

The light tunnel 2 is provided with a plurality of reflective surfaces therein, so that the non-uniform light source by the point light source incident into the light tunnel is diffusely reflected to become a surface light source to the exit side. . This light emitting device 1 may vary depending on the characteristics of the light emitting device. However, since the light emitting device 1 is a point light source in most cases, it is essential to a projection system.

Preferably, the light tunnel is provided with an incident side larger than an emission side. This is because the light emitted from the light emitting device 1 is diffused in multiple directions due to the diffusivity of the light. Therefore, in order for the diffused light to flow into the inside of the light tunnel 2 with little loss, it is preferable that the entrance side of the light tunnel 2 is wide. In the case where the light exiting side of the light tunnel 2 is provided large, there is a high possibility that the light emitted from the light tunnel 2 expands more broadly than when the light exiting side is provided small. In this case, a larger problem arises in the design of the optical path, such as the design of the condensing lens, on the output side of the light tunnel. Therefore, the output side of the light tunnel 2 should be as narrow as possible. As such, the light tunnel having a smaller size at the exit side than the entrance side may be referred to as a light funnel. The light funnel is proposed to be connected in a straight line on the incidence side and the exit side, but this is due to the material used in the manufacture of the light funnel is glass, etc., if there is no problem due to such a material in the form of a straight line It will not be limited to.

The color wheel 3 is an article to which a floodlight plate having a plurality of colors is radially attached. The color wheel 3 is rotated at high speed by the motor 4 in synchronization with the DMD 6 in a constant sequence corresponding to the color. Therefore, only the color corresponding to the current operating state of the DMD 6 passes through the color wheel 3 and blocks the remaining light. For example, when the DMD 6 is in a red on / off reflection state, the red floodlight plate is aligned with the exit side of the light tunnel 2 in the color wheel 3.

In the projection system as described above, the white light emitted from the light emitter 1 is totally incident without leaking to the incidence side of the light tunnel 2 to the outside. Then, in the light tunnel 2, after the surface light is sourced to make the luminance of the image uniform, the white light is changed to the time-divided red-green-blue tricolor by the color wheel 3.

Thereafter, after passing through the required optical path with a predetermined length, the image signal is time-divided while passing through the DMD 6 synchronized with the color wheel 3, and then projected through the projection lens 7. The projected light forms an image in front of or behind the screen for viewing by the viewer.

The projection system according to the present embodiment adopts a structure in which the light tunnel 2 is directly placed on the emission side of the light emitter 1, so that a component for focusing light emitted from the light emitter 1 is not required separately. This is because the output side of the light tunnel 2 can receive the light emitted from the light emitter 1 into the light tunnel 2 almost entirely without leakage. This may be achieved by various reasons such as reducing the size of the light emitter 1 itself, reducing the emission angle of the light emitter, and increasing the incident area of the light tunnel 2. Of course, it is natural that the incident side size is larger than the exit side size of the light tunnel 2.

According to the present embodiment, since the light tunnel 2 is placed in front of the light emitting body 1 directly in front of the emission side, a structure for focusing light emitted from the light emitting body 1 is not required. Therefore, the overall size of the projection system is reduced, and the space for placing other members forming the optical path can be secured widely, and the light tunnel can be used to increase the efficiency of the surface light source, more specifically, the uniformity of luminance in the entire image area. Even in the case where the length of is increased, a space for additionally lengthening the light tunnel can be secured. In addition, it is possible to eliminate the light leakage due to the light leakage due to the medium of the collimator required on the emission side of the conventional light emitting body, the decrease in the reflection efficiency due to the diffuse reflection, and the decrease in the reflection efficiency caused by the reflector. Of course, the image quality of the projection system is improved and the brightness is also easily expected.

&Lt; Embodiment 2 >

The second embodiment is characterized by providing a surface light source device and a projection system that do not require a color wheel. In addition, each configuration and each operation described in the first embodiment will be applied to the second embodiment as it is unless otherwise described. In addition, the advantages of the surface light source device and the projection system according to the first embodiment also apply to the case of the second embodiment unless otherwise specified.

2 is a diagram for explaining a projection system according to a second embodiment.

Referring to FIG. 2, the first, second and third light emitters 11, 12 and 13 which emit light of three colors of red cyan, respectively, and the point light sources of the light emitters 11, 12 and 13, respectively. The first, second and third light tunnels 21, 22 and 23 for converting the emitted light into a surface light source and the outgoing light which is the surface light source emitted from the light tunnels 21, 22 and 23; Prisms 30 for combining, a condensing lens 40 for condensing the light emitted from the prism 30, and a DMD 50 for reflecting an image signal on light emitted through the condensing lens 40. And a projection lens 60 for projecting the light reflected from the DMD 50 onto the screen. The prism 30 is called an x-prism so that light incident through three incident lights is emitted to one emission surface through a sheet whose reflection state is changed according to the wavelength of light on the inner contact surface of each glass body constituting the prism. do.

Even in the second embodiment, various components such as a relay lens and a reflecting mirror may be further disposed between the condensing lens 40 and the DMD 50.

The operation of the second embodiment will be described.

The light emitters 11, 12 and 13 may emit light instantaneously. Therefore, when the DMD 50 is in the red on / off reflection state, only the light emitting body emitting red color among the light emitting members 11, 12 and 13 emits light and is emitted through the prism 30. Of course, when the DMD 50 is in the green on / off reflection state, only the green light emitter is emitted, and when the DMD 50 is in the blue on / off emission state, only the blue light emits light and is emitted through the prism 30. As such, the DMD 50 and the light emitters 11, 12, and 13 are reflected while being synchronized with each other, so that the image of the red-green-blue tricolor is imaged on the screen in a time-division manner. It is recognized as a synthesized state, and thereby an image can be viewed.

In the present embodiment, unlike the first embodiment, since the color wheel is not required, power consumption and noise generated by the motor generated inside the projection system can be reduced. In addition, the synchronization between the color wheel and the DMD is not necessary, so that an advantage of not requiring precise control as compared with the first embodiment can be obtained.

In the case of the second embodiment, three light emitters and light tunnels corresponding to the respective light emitters are used, but as another modification, two or more light emitters may be installed at a time on a mount supporting the light emitters. In this case, the prism may be provided accordingly, and the area on the incidence side of the light tunnel may be disposed a little wider.

As another variant, in the case of emitting light of two wavelength bands, for example, red-blue two colors from a single light emitter, the same effect can be obtained by selectively transmitting the light emitted from one light emitter. will be. In this case, for example, a color wheel or the like may be further used as the light sorting means for selectively transmitting each light emitted from the two wavelength bands.

The idea of the present invention may be similarly applied to a projection system using a three-panel display element using an LCD and the like and a projection system using a transmissive display element.

According to the present invention, the passage of the light is simplified, thereby reducing the possibility of failure in the optical path, and the optical path is simplified, which makes the manufacturing convenient, the number of parts is reduced, the manufacturing cost is reduced, and the cost of the projection system is low, but the durability This can be improved and contribute to the increase in the image quality and luminance of the projection system.

1 is a structural diagram of a projection system according to a first embodiment;

2 is a structural diagram of a projection system according to a second embodiment;

Claims (6)

White emitters; A light tunnel placed in front of the white light emitter exiting side; A color wheel placed on the exit side of the light tunnel; A display element for mounting an image signal on the light transmitted through the color wheel; And And a projection lens for projecting the light emitted from the display element onto a screen. At least two emitters; A light tunnel placed in front of the exit side of each of the at least two light emitters; A prism placed on an exit side of the light tunnel to emit light in a single direction; A display element for mounting an image signal on the light passing through the prism; And And a projection lens for projecting the light emitted from the display element onto a screen. illuminant; A light tunnel which is placed in front of the light emitting body emitting side and directly receives the light emitted from the light emitting body without reflection or condensing action between the light emitting body and the light emitting body; A display element for mounting an image signal on a surface light source passing through the light tunnel; And And a projection lens for projecting the light emitted from the display element onto a screen. The method according to any one of claims 1 to 3, And the light tunnel has a larger area on the incident side than an area on the exit side. illuminant; And And a light tunnel in which the incidence side of the light emitter is directly placed on the emission side of the light emitter. The method of claim 5, And said light tunnel has a surface light source device having an incident side larger than that of the exit side.

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