KR100737613B1 - Apparatus for projecting color image and optical system for the same - Google Patents

Abstract

The present invention discloses a color image projection apparatus and its illumination optical system, wherein LEDs which generate and emit color light beams of red (R), green (G), and blue (B), respectively, and each color light beam emitted therefrom as uniform light. A rod lens for blending is disposed at each coordinate axis on an arbitrary XY plane coordinate, and a reflection mirror, which is rotated in step units in synchronization with an image realization signal applied to an image generating means such as a DMD, is placed on the origin of the XY plane coordinate. It is arranged to have a configuration that can implement a color image by separately interfering the traveling path of each color light beam to be incident on the road lens. According to such a configuration, by removing the color mixing optical system, which is a light efficiency deterioration factor of the existing illumination optical system, and improving the light efficiency, it is possible to not only improve the brightness and the clarity of the image light, but also to effectively extend the lifespan and downsizing. And its illumination optical system.

Projection device, projector, light source, illumination optical system, rotating mirror

Description

Color image projection apparatus and its illumination optical system {APPARATUS FOR PROJECTING COLOR IMAGE AND OPTICAL SYSTEM FOR THE SAME}

1 and 2 are schematic configuration diagrams showing an illumination optical system of a conventional color image projection apparatus, respectively;

3 is a schematic perspective view showing a color image projection apparatus and an illumination optical system thereof according to the present invention;

4 is a schematic plan view showing a color image projection apparatus and an illumination optical system thereof according to the present invention shown in FIG.

5 to 7 are schematic plan views shown for explaining the operating state of the color image projection apparatus and its illumination optical system according to the present invention.

<Description of Symbols for Main Parts of Drawings>

101, 102, 103 ... LED light source 100 ... lighting optical system

110 ... road lens 111 ... condensing lens

120 Means for changing light path 121 Drive motor

122 ... swivel shaft 123 ... reflective mirror

200 ... Image generation means 300 ... Projection optical system

C ... main controller

The present invention relates to an image projection apparatus such as a projection television set or a projector, and more particularly, to a color image projection apparatus using a light emitting element such as a light emitting diode (LED) or a laser diode (LD) as a light source and an illumination optical system thereof. It is about.

For example, an image such as a projection television set or a projector that displays desired image information by projecting an image generated by an image generating means such as a digital mirror device (DMD) or a liquid crystal display (LCD) onto a screen using a separate light source. In the projection apparatus, an illumination optical system having a light source and an optical lens has a great influence on image quality. In general, a high-pressure discharge lamp such as a mercury lamp, a metal halide lamp, a xenon lamp, or the like is mainly used as a light source used in an illumination optical system of an image projection apparatus.

In recent years, however, light emitting diodes (LEDs), which have been greatly improved in brightness, are used as light sources for simple lighting devices such as flashlights and traffic lights, as well as light sources for automobile lighting devices, as well as for illuminating video projection devices. Attempts have been made to broaden the light source. Such an LED light source has excellent color reproducibility compared to a discharge lamp, and in particular, it is advantageous to realize a mobile image projection device that is easy to carry because it is advantageous for long life and miniaturization.

As shown in FIG. 1, the illumination optical system of the conventional color image projection apparatus using the LED as a light source for miniaturization and long life is shown as red (R), green (G), blue ( B) LEDs 11, 12 and 13 emitting color light beams of color, and color light beams emitted from the LEDs 11, 12 and 13, respectively, are focused and emitted in a state where the divergence angle is reduced. X as a color mixing optical means for selectively reflecting and / or transmitting a plurality of condensing lenses 20 having a funnel-shaped structure and a light beam of a specific polarization component of the light beams respectively emitted from the condensing lenses 20. And a rod lens 40 as a light mixing means for focusing, diverging or reflecting the polarized beams routed by the X-cube prism 30 and mixing them into uniform light. Here, reference numeral 10 in the drawings denotes a substrate for forming the light source package by mounting the LEDs 11, 12, 13 and the condenser lens 20, respectively.

Meanwhile, FIG. 2 illustrates an illumination optical system of another conventional color image projection apparatus, and the color mixing optical means and the light mixing means are respectively a band pass filter 50 and a light tunnel 60. It has a configuration replaced with). Here, the same reference numerals as the reference numerals of the drawings shown above represent the same components.

According to the illumination optical system of the conventional color image projection apparatus having the configuration as described above, since the light beams respectively emitted from the LEDs 11, 12, 13 are unpolarized with a relatively large incident angle, the X-cube prism 30 and the band pass filter (Band pass filter) 50 has a problem that the light efficiency of the illumination is significantly lowered as the loss of light increases due to a decrease in the transmission / reflectance.

Accordingly, the present invention has been made to solve the problems of the illumination optical system of the conventional color image projection apparatus as described above, and an object of the present invention is to suppress the lost light by the exclusion of color mixing optical means to reduce the light efficiency. It is to provide an illumination optical system of a color image projection apparatus further improved.

Another object of the present invention is to provide a color image projection value which is more effective for improving image quality, long life, and miniaturization by improving light efficiency by using an illumination optical system for achieving the above object.

In order to achieve the above object, the illumination optical system of the color image projection apparatus according to the present invention is disposed on different coordinate axes on an arbitrary XY plane coordinate, respectively, and generates and emits color light of different wavelength bands toward the coordinate origin. A first light emitting device, a second light emitting device, and a third light emitting device; An optical lens disposed coaxially with a coordinate axis symmetrical with any one of the first to third light emitting elements so as to transfer the color light beams respectively emitted from the first to third light emitting elements to an image generating means; And optical path changing means disposed on the XY plane coordinate origin to alternately enter the optical lens by interfering with the traveling paths of the color light beams emitted from the first to third light emitting devices, respectively. do.

In order to achieve the above object, the color image projection apparatus according to the present invention enlarges the image generation means for generating the color image light by using the illumination light emitted from the illumination optical system, and the image light generated by the image generation means. A color image projection apparatus including a projection optical system for projecting and displaying an image, wherein the illumination optical system is arranged on different coordinate axes on an arbitrary XY plane coordinate to generate color light of different wavelength bands toward the coordinate origin, respectively. A first light emitting device, a second light emitting device, and a third light emitting device; An optical lens disposed coaxially with a coordinate axis symmetrical with any one of the first to third light emitting elements so as to transfer the color light beams respectively emitted from the first to third light emitting elements to an image generating means; And optical path changing means disposed on the XY plane coordinate origin to alternately enter the optical lens by interfering with the traveling paths of the color light beams emitted from the first to third light emitting devices, respectively. do.

In the color image projection apparatus and illumination optical system according to the present invention having the above-described configuration, the optical path changing means includes: a rotation axis passing through the coordinate origin in a state orthogonal to the XY plane coordinates so as to be rotationally driven by a drive source; And a reflection mirror supported by the rotating shaft and controlled to rotate in steps of predetermined intervals.

According to a feature of the present invention, the reflection mirror is driven in synchronization with the image realization signal applied to the image generating means by rotating the color light beams emitted from the first to third light emitting elements, respectively, in steps of predetermined intervals. And interfering with the path to alternately enter the optical lens.

According to an aspect of the present invention, the first to third light emitting devices may be selected as a light source, LED or LD that generates red light, green light and blue light, respectively. In addition, the optical lens may be selectively adopted, for example, a rod lens or a lighter tunnel made of a rectangular glass rod.

Hereinafter, a color image projection apparatus and an illumination optical system thereof according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 and 4, the color image projection apparatus P according to the present invention includes image generation means 200 such as a DMD or LCD for generating color image light using illumination light emitted from the illumination optical system 100. And a projection optical system 300 for expanding and projecting the image light generated by the image generating means 200 to display it as a color image.

The illumination optical system 100 is a component that characterizes the present invention, and as shown, the LEDs 101 and 102 that generate and emit color light beams of red (R), green (G), and blue (B), respectively, as a light source. (102) and the rod lens 110 for mixing each color light beam emitted therefrom into uniform light is disposed at each coordinate axis on an arbitrary XY plane coordinate, and the LED 101 is located on the XY plane coordinate origin. 102 and 103 and the optical path changing means 120 is disposed in the center of the rod lens 110.

According to another aspect of the present invention, the light source may be a laser diode (LD) for generating and emitting color light beams of red (R), green (G), blue (B), respectively.

According to an embodiment of the present invention, the rod lens 110 is disposed on a coordinate axis symmetrical with the blue (B) LED 103 and a red (R) LED 101 and green color on a coordinate axis orthogonal to the coordinate axis. (G) The LEDs 102 are disposed at symmetrical positions, respectively. The LEDs 101, 102 and 103 are arranged to emit light beams toward the origin of the XY plane coordinates, and the light incident surface of the rod lens 110 and the LEDs 101 and 102. The light exit surfaces of 103 are arranged to lie on the same circumference. This arrangement structure is not a configuration that specifically limits the present invention, of course, it is possible to apply other embodiments modified to various forms of arrangement structure.

The rod lens 110 mixes the color light beams emitted from the LEDs 101, 102, 103 into uniform light by focusing, diverging, or reflecting the light, and then enters the image generating means 200 as illumination light. As the light mixing means, an optical member such as, for example, a cuboid glass rod or a light tunnel may be selectively employed.

The optical path changing means 120 includes a drive motor 121, a rotation axis 122 passing through the coordinate origin in a state orthogonal to the XY coordinate plane so as to be rotationally driven by the drive motor 121, and the rotation axis 122 thereof. And a reflection mirror 123 which is rotated and driven in steps of predetermined intervals.

According to a feature of the present invention, the reflection mirror 123 is incident on the road lens 110 alternately by interfering individually the traveling path of the color light beam emitted from each of the LED (101) (102) (103) According to a control operation of the main controller C, the main controller C is controlled to rotate in synchronization with an image realization signal applied to the image generating means 200 in steps of predetermined intervals.

According to one aspect of the present invention, the reflective mirror 123 is preferably a coating layer having a high reflectance in the visible light is formed on the surface, for example, the galvanometer mirror (Galvanometer Mirror) mainly used in the laser scanning method is effective Can be used.

In the drawing, reference numeral 111 denotes a condenser lens for condensing the color light beams emitted from the LEDs 101, 102 and 103, respectively, and emitting them in a reduced state of divergence angle. As shown, the condensing lens 111 is formed to have a funnel shape or a tapered cylindrical shape whose outer diameter is gradually inclined from the light incidence side to the light outgoing side, so that the light exit face is formed wider than the light incidence plane. Due to such a shape structure, the condensing lens 111 focuses the emitted light emitted from each of the LEDs 101, 102, 103 and enters the rod lens 110 while reducing the divergence angle. By suppressing the light to a minimum it is to function to further improve the light efficiency.

Hereinafter, the operation of the color image projection apparatus P and the illumination optical system 100 according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

That is, when the main controller C applies the image realization signal to the image generating means 200 according to the driving signal of the image projection apparatus, the driving motor 121 may operate the reflection mirror 123 in synchronization with the signal. It will drive the unit step rotation.

For example, while the green light signal is applied to the image generating means 200, as shown in FIG. 5, the reflective surface of the reflective mirror 123 faces the light exit surface of the green (G) LED 102. The step rotation drive is set to be inclined approximately 45 degrees with respect to the XY plane coordinate axis. The green light beam emitted from the green (G) LED 102 is totally reflected by the reflective surface of the reflective mirror 123 set as described above and is incident to focus on the rod lens 110.

While the red light signal is applied to the image generating means 200, the reflective surface of the reflective mirror 123 faces the light exit surface of the red (G) LED 101 as shown in FIG. 6. The step rotation drive is set to be inclined approximately 45 degrees with respect to the XY plane coordinate axis. The red light beam emitted from the red (R) LED 101 is totally reflected by the reflective surface of the reflective mirror 123 set as described above and is incident to focus on the rod lens 110.

In addition, while the blue light signal is applied to the image generating means 200, the reflective mirror 123 is in line with the blue (G) LED 103 and the rod lens 110 as shown in FIG. The step rotational drive is set to be placed on the X axis of the XY plane coordinates in an aligned state. According to the setting attitude of the reflective mirror 123, most of the blue light beams emitted from the blue (R) LED 103 are incident on the rod lens 110 so as to be focused.

Therefore, the reflection mirror 123 is controlled to rotate in steps of predetermined intervals in synchronization with the image implementation signal applied to the image generating means 200 as described above. As a result, optical operations and operations are performed repeatedly such that each of the color light beams emitted from each of the LEDs 101, 102, and 103 alternately causes any one to be incident on the rod lens 110.

On the other hand, the color image signal applied to the image generating means 200 is input with a speech time during which the signal is not applied while the color light beam is changed between each color signal.

Accordingly, by rotating the unit step so that the setting position of the reflection mirror 123 is changed during the conversion time, the light beams corresponding to the applied color image signal are totally reflected to be incident on the rod lens 110. Given.

The rod lens 110 mixes each incident color light beam into uniform light by focusing, diverging, or reflecting the light, and injects the color light beam into the image generating means 200 as illumination light, and the image generating means 140 is incident. Color image light may be generated using the illumination light, and the desired color image may be displayed by expanding and projecting the image light through the projection optical system 300.

Therefore, the image projection apparatus and the illumination optical system according to the present invention, which performs the above-described configuration, optical action and operation, are X-cube prism or bandpass filter which acted as a light efficiency deterioration factor in the illumination optical system of the conventional image projection device. A color image can be realized in a state where the light efficiency is further improved by the configuration excluding the color mixing optical system.

As described above, according to the image projection apparatus and the illumination optical system according to the present invention, by suppressing the loss of light by eliminating the color mixing optical means provided in the existing illumination optical system can further improve the light efficiency, It is possible to obtain an image quality improvement and a long life effect, and in particular, it is more advantageous for miniaturization, so that it can be effectively applied to the manufacture of a small portable image projection apparatus.

The present invention is not limited to the above-described specific preferred 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. .

Claims (12)

A first light emitting device, a second light emitting device, and a third light emitting device, each of which is disposed on different coordinate axes on arbitrary X-Y plane coordinates and generates and emits color light of different wavelengths toward the coordinate origin; An optical lens disposed coaxially on a coordinate axis symmetrical with any one of the first to third light emitting elements so as to transfer the color light beams respectively emitted from the first to third light emitting elements to an image generating means; And optical path changing means disposed on the XY plane coordinate origin to alternately interfere with the traveling paths of the color light beams respectively emitted from the first to third light emitting elements to be incident on the optical lens. Illumination optical system of color image projection apparatus. The method of claim 1, wherein the optical path changing means, A drive source; A rotation axis passing through a coordinate origin in a state orthogonal to the X-Y plane coordinates so as to drive rotation by the drive source; And a reflection mirror supported by the rotating shaft and controlled to rotate in steps of predetermined intervals. The method of claim 2, The reflection mirror is synchronized with an image realization signal applied to the image generating means so as to alternately interfere with the traveling paths of the color light beams emitted from the first to third light emitting elements, respectively, to the image generating means. Illumination optical system of a color image projection apparatus characterized in that it is controlled to drive rotation in units of steps. The method of claim 1, The first to the third light emitting device is an illumination optical system of the color image projection apparatus, characterized in that any one selected from LED and LD for generating and emitting red light, green light and blue light, respectively. The method of claim 1, The optical lens is an illumination optical system of a color image projection apparatus, characterized in that any one selected from a rod lens and a lighter tunnel. The method of claim 1, And a condenser lens on the light exit side of the first, second and third light emitting elements, the condenser lens for incident on the optical lens in a state in which the divergence angle of the outgoing light is reduced. A color image projection apparatus comprising image generation means for generating color image light using illumination light emitted from an illumination optical system, and a projection optical system for magnifying and projecting image light generated by the image generation means to display an image. , The illumination optical system, A first light emitting device, a second light emitting device, and a third light emitting device, each of which is disposed on different coordinate axes on arbitrary X-Y plane coordinates and generates and emits color light of different wavelengths toward the coordinate origin; An optical lens disposed coaxially on a coordinate axis symmetrical with any one of the first to third light emitting elements so as to transfer the color light beams respectively emitted from the first to third light emitting elements to an image generating means; And optical path changing means disposed on the XY plane coordinate origin to alternately interfere with the traveling paths of the color light beams respectively emitted from the first to third light emitting elements to be incident on the optical lens. Color image projection apparatus. The method of claim 7, wherein the light path changing means, A drive source; A rotation axis passing through a coordinate origin in a state orthogonal to the X-Y plane coordinates so as to drive rotation by the drive source; And a reflection mirror supported by the rotating shaft and controlled to rotate in steps of predetermined intervals. The method of claim 8, The reflection mirror is rotated and driven in steps of predetermined intervals in synchronization with an image realization signal applied to the image generating means, and alternately by interfering with the traveling paths of the color light beams emitted from the first to third light emitting devices, respectively. Color image projection apparatus characterized in that the transfer to the image generating means. The method of claim 7, wherein The first to the third light emitting device is a color image projection apparatus, characterized in that any one selected from LED and LD for generating and emitting red light, green light and blue light, respectively. The method of claim 7, wherein The optical lens is a color image projection apparatus characterized in that any one selected from the rod lens and the lighter tunnel. The method of claim 7, wherein And a condenser lens for incident on the optical lens in a state in which the divergence angle of the outgoing light is reduced on the light output side of the first to third light emitting devices.

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