KR20060041420A - Drum-type reflective collarwheel and display apparatus using thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color wheel and a display device using the same, and in particular, an optical filter is arranged along a cylindrical shape, and a drum type reflective color wheel reflecting the light while the optical filter is rotated by the rotation of a motor and a display using the same. Relates to a device.

Color Wheel, Drum Type, Reflective, Display Unit

Description

Drum type reflective collarwheel and display apparatus using the same             

1A and 1B are views showing the configuration of a conventional plate-shaped color wheel.

2 is a view showing the configuration of a conventional funnel-type color wheel.

3A and 3B show the configuration of a conventional cylindrical color wheel.

4 is a perspective view of the color filter of FIGS. 3A and 3B.

5 is a perspective view and a cross-sectional view of a drum-type reflective color wheel according to an embodiment of the present invention.

6 is a view for explaining a process of obtaining the reflected light of the drum-type reflective color wheel according to an embodiment of the present invention.

7 is a block diagram of a display device using a drum-type reflective color wheel according to an embodiment of the present invention.

8 is a view for explaining an optical path of the illumination lens system of FIG.

9 is an exemplary view of the diffractive optical modulator of FIG. 7.

10 is a view for explaining a diffraction angle of the diffractive optical modulator of FIG.

FIG. 11 is a view for explaining diffracted light of the diffractive light modulator of FIG. 7. FIG.                 

12A to 12E are diagrams for describing the color screening filter of FIG. 7.

<Explanation of symbols for the main parts of the drawings>

100: motor 110: optical filter

120: light filter attachment portion 200: light source

210: light collecting unit 220: lighting lens system

230: drum type reflective color wheel 240: diffraction type optical modulator

250: Fourier filter 260: projection system

270 screen

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color wheel and a display device using the same, and in particular, an optical filter is arranged along a cylindrical shape, and a drum type reflective color wheel reflecting the light while the optical filter is rotated by the rotation of a motor and a display using the same. Relates to a device.

In general, optical signal processing has advantages of high speed, parallel processing capability, and large-capacity information processing, unlike conventional digital information processing, which cannot process a large amount of data and real-time processing, and design a binary phase filter using spatial light modulation theory. Research on fabrication, optical logic gates, optical amplifiers, image processing techniques, optical devices, optical modulators, etc.

The dual spatial optical modulator is used in the fields of optical memory, optical display, printer, optical interconnection, hologram, and the like, and research on the development of a display device using the same is underway.

Image display systems based on spatial light modulators are an alternative to image display systems based on cathode ray tubes. The spatial light modulator provides high resolution without the bulk of the CRT system.

One method of providing color images in a spatial light modulator display system is called 'sequential color'. All pixels of the picture frame are addressed sequentially in different colors. For example, each pixel has a value of red, green, and blue.

Next, during each frame period, the pixels of the frame are optionally addressed with their red, green and blue data. In this type of system, one type of sequential color filter is synchronized to the data as a color wheel with three parts of the same color, so that when the data for each color is displayed by the spatial light modulator, Light incident on the modulator is filtered by the color wheel.

1 is a view showing the configuration of a conventional plate-shaped color wheel, referring to the conventional plate-shaped color wheel 10 is a color filter 6 for transmitting only a light beam of a wavelength corresponding to each color of the white light beam and And a coupler (Coupler) 4 to which the color filter 6 is attached, and a motor 2 attached to the coupler 4 to generate rotational force.                         

The plate-shaped color wheel 10 sequentially separates the color of the light beam by rotating the coupler 4 and the color filters 6R, 6G, and 6B attached thereto in response to the rotational speed of the motor 2. .

2 is a view showing the configuration of a conventional funnel-type color wheel, referring to the drawing, the conventional funnel-type color wheel 10 'is a funnel body configured to be a funnel so that the foil member 9 is attached, the body portion And a color filter (7) for attaching only a light beam of a wavelength corresponding to each color among the white light beams, and a motor (2) for generating rotational force in the body part.

The funnel-type color wheel 10 'sequentially separates the color of the light beam by rotating the fuselage and the color filter 7 attached to the funnel in response to the rotational speed of the motor 2.

3 is a view showing the configuration of a conventional cylindrical color wheel, the conventional cylindrical color wheel is a cylindrical color filter 36 for transmitting only a light beam of a wavelength corresponding to each color of the white light beam, and the color filter A coupler 34 to which the 36 is attached is provided, and a motor 32 attached to the coupler 34 to generate a rotational force. In the cylindrical color filter 36, R, G, and B color filters are configured in a cylindrical shape as shown in FIG.

On the other hand, when the display device is implemented using the plate, funnel, or cylindrical color wheel as described above, a portion of the device may have a region through which light is not transmitted or reflected, resulting in a disconnection portion of the image projected on the screen. There is a problem.

In addition, when the display device is implemented using the funnel-shaped or cylindrical color wheel as described above, there is a problem in that light loss occurs because a part of the device and a corresponding part reflect or absorb color.

Accordingly, an object of the present invention is to provide a drum-type reflective color wheel and a display device using the same, which are devised to solve the above problems and can minimize light loss.

The present invention for achieving the above object is a cylindrical type of sequentially coated with a film that reflects only the light of the desired color on the surface and transmits the rest so as to selectively reflect only the light of the desired color in the multiple beams incident from the outside Filter unit; A driving unit for rotating the filter unit; And a mounting part for mounting the filter part to the driving part.

In addition, the present invention, the light source for generating a multi-beam; An illumination lens system which emits light by changing the light emitted from the light source into linear parallel light; In order to selectively reflect only light of a desired color among multiple incident lights in a cylindrical shape, a film that reflects only light of a desired color on the surface is sequentially coated. When multiple beams are incident from the illumination lens system, only light of a desired color is sequentially rotated. Color wheel system that reflects; A diffraction type optical modulator for modulating the reflected light emitted from the color wheel system to produce diffracted light having a plurality of diffraction coefficients; A Fourier filter system for passing diffracted light of a desired order in diffracted light having a plurality of diffraction coefficients emitted from the optical modulator; And a projection system for projecting the diffracted light of the desired order filtered by the Fourier filter system onto the screen.

Now, a drum type reflective color wheel and a display device using the same according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 5.

5 is a view showing a drum-type reflective color wheel according to an embodiment of the present invention.

Referring to the drawings, the drum-type reflective color wheel according to an embodiment of the present invention includes a motor 100, the optical filter unit 110, the optical filter attachment portion 120.

The optical filter unit 110 includes a R optical filter 110R that reflects red and transmits other colors, a G optical filter 110G that reflects green and transmits other colors, and a blue light reflects and transmits other colors. The B light filter 110B is sequentially arranged along a cylindrical shape, and is attached to and fixed to the light filter attachment part 120.

The optical filter unit 110 is rotated by the motor 100 to reflect the light and other light is transmitted. A reflector is further provided at the center of the optical filter unit 110 to allow the transmitted light to be incident to a point far from the reflected light, thereby preventing interference between the lights.

The R optical filter 110R, the G optical filter 110G, and the B optical filter 110B may be implemented using, for example, a color screening filter. A material that transmits blue is coated, and a material that transmits red and blue is coated in the G light filter 110G area, and a material that transmits red and blue is coated. A blue and red and green color is reflected in the B light filter 110B area. The permeable material is coated.

6 is a view for explaining the reflection and transmission of the incident light incident on the drum-type reflective color wheel according to an embodiment of the present invention.

Referring to the drawings, incident light incident on the drum-type reflective color wheel according to an embodiment of the present invention is parallel light, for example, linear light as shown in the cross section, and includes light of various wavelengths.

When linear parallel light 1 including light of various wavelengths, for example, red, blue, and green, is incident on the R optical filter 110R as shown in the drawing, red is reflected to reflect the reflected light 2. And the remaining blue and green are transmitted to form the transmitted light (3).

At this time, the optical filter 110 is rotated by the motor 100 and while the R optical filter 110R is located on the optical path, the red light is reflected by the R optical filter 110R to form the reflected light 2. Next, when the G optical filter 110G is positioned on the optical path, the incident light is reflected and green light of the incident light is reflected to form the reflected light 2, and the rest is transmitted. Subsequently, the optical filter 110 rotates, and this time, when the B optical filter 110B is positioned on the optical path, blue light of the incident light is reflected to form the reflected light 2, and the rest is transmitted.

7 is a block diagram of a display device using a drum-type reflective color wheel according to an embodiment of the present invention.

Referring to the drawings, the display device using a drum-type reflective color wheel according to an embodiment of the present invention, a light source system 200, a light collecting unit 210, an illumination lens system 220, a drum-type reflective color wheel 230 And a diffraction type optical modulator 240, a Fourier filter system 250, a projection system 260, and a screen 270.

The light source system 200 includes a plurality of light sources 201a to 201c, and the light collecting unit 210 includes one mirror 211a and a plurality of color-specific mirrors 211b and 211c.

The plurality of light sources 201a to 201c include, for example, a red light source 201a, a green light source 201b, and a blue light source 201c. The light sources 201a to 201c used herein may be light sources manufactured using semiconductors such as light emitting diodes (LEDs) and laser diodes (LDs). Such semiconductor light sources have many properties suitable for use in color display devices compared to other light sources.

The reflection mirror 211a of the condenser 210 reflects the red light emitted from the red light source 201a toward the illumination lens system 220, and the dividing mirror indicated by reference numeral 211b is the red light incident from the reflection mirror 211a. The light is emitted through the green light source 201b and reflected by the illumination lens system 220.

In addition, the dichroic mirror denoted by reference numeral 211c transmits the red light and the green light incident from the dichroic mirror 211b at the front end and reflects the red light incident from the red light source 201a toward the illumination lens system 220.

As described above, blue light, green light, and red light are collected by one reflection mirror 211a and a plurality of color-mirror mirrors 211b and 211c to form a multi-beam to form a single illumination system.

Next, the illumination lens system 220 converts the condensed multiple beams into linear parallel light and enters the optical modulator 240 through the drum-type reflective color wheel 230.                     

An example of a cross-sectional view of light used here is shown in Fig. 8A. Referring to Fig. 8A, the cross section of the light is circular, and the intensity profile of the light is shown in Fig. 8B. Gaussian distribution.

The illumination lens system 220 changes the incident light into linear parallel light having an elliptical cross section. The illumination lens system 220 includes a cylinder lens 221 and a collimator lens 222.

That is, the illumination lens system 220 converts the collected multiple beams into linear light in the horizontal direction with respect to the optical path direction and enters the diffractive light modulator 240 through the drum-type reflective color wheel 230.

Here, the cylinder lens 221 applies balanced light as shown in FIG. 8C to horizontally incident incident light to a corresponding diffractive light modulator 240 positioned horizontally in the optical path direction. The light is converted into linear light in the horizontal direction and incident on the drum-type reflective color wheel 230 through the corresponding collimator lens 222.

As shown in FIG. 8, the collimator lens 222 includes a concave lens 222a and a convex lens 222b.

The concave lens 222a extends the linear light incident from the cylinder lens 221 up and down as shown in FIG. 8D to enter the convex lens 222b. The convex lens 222b emits incident light incident from the concave lens 222a by changing parallel light as shown in FIG. 8E. 8A is a perspective view of an optical system including a light source, a cylinder lens, and a collimator lens, FIG. 8B is a plan view, FIG. 8C is a side cross-sectional view, and FIG. It is also.                     

On the other hand, the drum-type reflective color wheel 230 as described above, when multiple linear parallel light is incident from the illumination lens system 220 reflects the light of each wavelength sequentially in the order of the optical filters arranged to diffraction light It enters the modulator 240 and transmits other light. At this time, the reflection time of each wavelength depends on the width of the optical filter in the drum type color wheel (230). If the width of the optical filter is large, it reflects light of each wavelength for a long time and transmits other light.

When the linear parallel light of a single wavelength is incident from the drum-type reflective color wheel 230, the diffractive light modulator 240 performs light modulation on the linear parallel light of the corresponding wavelength during incident time to form diffracted light and form diffraction light. Light is incident on the Fourier filter system 250.

At this time, the diffraction angle of the diffracted light formed by the diffraction light modulator 240 is proportional to the wavelength, and the diffraction light modulator 240 usable here is capable of various types of diffraction light modulators. An open hole based diffractive light modulator is shown.

Referring to the drawings, the open hole-based diffractive light modulator is composed of a silicon substrate 901, an insulating layer 902, a lower micromirror 903, and a plurality of elements 910a to 910n. Here, although the insulating layer and the lower micromirror are configured as separate layers, if the insulating layer has a property of reflecting light, the insulating layer itself can function as the lower micromirror.

The silicon substrate 901 includes depressions to provide air space to the elements 910a to 910n, an insulating layer 902 is stacked, and a lower micro mirror 903 is deposited on the upper portion, and the depressions The lower surfaces of the elements 910a to 910n are attached to both sides that deviate. As the material constituting the silicon substrate 901a, a single material such as Si, Al ₂ O ₃ , ZrO ₂ , Quartz, SiO _2, or the like is used. It can also form using.

The lower micromirror 903 is deposited on the silicon substrate 901 and reflects and diffracts incident light. As a material used for the lower micromirror 903, metal (Al, Pt, Cr, Ag, etc.) may be used.

The elements (typically described only with reference to 910a but the same are the same) have a ribbon shape and the lower surfaces of both ends are recessed of the silicon substrate 901 so that the center portion is spaced apart from the depression of the silicon substrate 901. The lower support part 911a which is attached to the both side area | regions which are out of a part is provided.

Piezoelectric layers 920a and 920a 'are provided on both side surfaces of the lower support 911a, and the driving force of the element 910a is provided by contraction and expansion of the provided piezoelectric layers 920a and 920a'.

The materials constituting the lower support 911a include Si oxide (for example, SiO _2, etc.), Si nitride series (for example, Si ₃ N _4, etc.), ceramic substrates (Si, ZrO ₂ , Al ₂ O _3, etc.), Si Carbides and the like. The lower support 911a may be omitted as necessary.

The left and right piezoelectric layers 920a and 920a 'are stacked on the lower electrode layers 921a and 921a' for providing the piezoelectric voltage and the lower electrode layers 921a and 921a ', and contract and expand when voltage is applied to both surfaces. The upper electrode layers 923a, which are stacked on the piezoelectric material layers 922a and 922a 'that generate vertical driving force, and provide piezoelectric voltages to the piezoelectric material layers 922a and 922a'. 923a '). When voltage is applied to the upper electrode layers 923a and 923a 'and the lower electrode layers 921a and 921a', the piezoelectric material layers 922a and 922a 'contract and expand to generate vertical movement of the lower support 911a.

Pt, Ta / Pt, Ni, Au, Al, RuO2, etc. may be used as electrode materials of the electrodes 921a, 921a ', 923a, and 923a', and are deposited by a sputter or evaporation method in a range of 0.01-3 μm. do.

On the other hand, the upper micro mirror 930a is deposited on the central portion of the lower support 911a and has a plurality of open holes 931a1 to 931a3. Here, the shape of the open holes 931a1 to 931a3 is preferably rectangular, but any closed curve such as round or elliptical may be used. If the lower supporter is formed of a light reflective material, it is not necessary to deposit the upper micromirror separately, and the lower supporter may function as the upper micromirror.

The open holes 931a1 to 931a3 allow incident light incident on the element 910a to penetrate the incident light to the lower micromirror 903 corresponding to the portion where the open holes 931a1 to 931a3 are formed. The mirror 903 and the upper micromirror 930a allow the pixels to be formed.

That is, for example, the (i) portion of the upper micro mirror 930a and the (i) portion of the lower micro mirror 903 in which the open holes 931a1 to 931a3 are formed may form one pixel.

At this time, incident light incident through the portion where the open holes 931a1 to 931a3 of the upper micromirror 930a are formed may be incident on a corresponding portion of the lower micromirror 903, and the upper micromirror 930a and the lower micromirror may be incident. The maximum diffracted light is generated when the interval of 903 becomes an odd multiple of lambda / 4. In addition, the open-hole diffraction light modulator usable in the present invention is disclosed in Korean Application No. P2004-030159.

On the other hand, as described above, the diffractive light modulator 240 diffracts each linear light incident from the illumination lens system 220 to form diffracted light, and then enters the diffracted light into the Fourier filter system 250.

In this case, the reflection angle of the formed diffracted light is shown in FIG. 10. Referring to the drawings, it can be seen that the incident angle and the reflection angle are the same. That is, when the incident angle enters θ ° to the diffractive optical modulator 240, the reflection angle becomes θ °. In the present invention, the incident angle uses 90 ° and the reflection angle becomes 90 °. The diffracted light formed by the diffractive light modulator 240 is shown in FIG. 11, where zero-order and ± first-order diffraction light are formed in the periodic direction of the grating, and the periodic direction of the grating is a horizontal line of linear parallel light. If it is the same as the direction, diffracted light as shown in Fig. 11 is formed.

The Fourier filter system 250 preferably includes a Fourier lens 251 and a color filter 252, and the Fourier lens 251 separates the incident diffracted light by orders, and the color filter 252 is a desired method. Only the order of diffracted light is transmitted.

In this case, the dichroic filter 252 used at this time, which is available, is well described in FIGS. 12A to 12E. That is, the Fourier lens 251 serves to separate the diffracted light incident from the optical modulator 240 for each order, and separates the 0th order and the ± 1th order.                     

The color filter 252 receives the multiple diffraction beams from the various light sources formed by diffraction by the diffractive light modulator 240 through the Fourier lens 251, and then selects a predetermined diffraction coefficient among the multiple diffraction beams. More specifically, only the multiple diffraction beams having a predetermined diffraction coefficient are selectively transmitted among the multiple diffraction beams having the 0th, + 1st and -1st diffraction coefficients, and are emitted to the projection system 260 described later. .

In this case, a plan view and a front view of the dichroic filter 252 used are shown in FIG. 12A. As shown in FIG. 12A, in the case of the zero-order diffraction slit, the zero-order diffraction beam of three colors of blue, green, and red is applied to the B region. The material to pass through is coated, and the part that does not overlap the area B in the G area is coated with the material that passes the zero-order diffraction beam of two colors, Green and Red, and the area that does not overlap the area B and the G area in the R area. Is coded for a material that only passes Red. The other areas are coated with a material that does not pass all three materials, blue, green, and red.

In addition, in the case of ± 1st slit, it is shown in FIG. 12B. In the region where R does not overlap with the G region, the red color is coated with a material that transmits, and in the region where R and G overlap, the material that transmits Red and Green Coated with a material that transmits green color in the G area, which does not overlap with the R or B area, and coated with a material that transmits Green and Blue in the area that overlaps the B area in the G area, In the area B, which does not overlap the area G, it is coated with a material to transmit only blue color.

In addition, in the case of ± 1st slit, it is shown in FIG. 12C. In the R region, the region not overlapping with the G region is coated with a material transmitting red color, and the region overlapping with R and G transmits Red and Green. Coated with a material that transmits red, green, and blue in areas where R, G, and B overlap, and where G is an area that overlaps R, an area that overlaps R, B, and G It consists of an area overlapping with.

The B region is composed of a region overlapping the G region and the R region, a region overlapping the G region, and a region transmitting only blue.

As described above, when the color filtering filter 252 is used, filtering is possible for a plurality of wavelengths by using one slit to enable separation of orders. This slit spacing can be determined by the following (Equation 1).

D = λ / Λ * f (λ)

Where D is the slit spacing, λ is the wavelength of the light source, Λ is the diffraction grating period, and f (λ) is the lens focal length of the Fourier lens 252 that varies with wavelength. Thus, in the case of the 0th order slit and the ± 1st order slit, the transmission and reflection patterns are shown in opposite directions.

On the other hand, the color-coded slits 252 may use a high reflectivity mirror method or a high transmittance transmission method. In the high transmittance method, as shown in FIG. 12D, two types of medium having a high refractive index and a low medium are λ / 4. Multi-coating alternately to have an optical thickness has a high transmittance, and in the high reflectance method, as shown in FIG. 12E, two types of medium having a high refractive index and a low medium are alternately made to have an optical thickness of λ / 4. However, in the middle, the optical thickness of the medium having high refractive index is λ / 2, and both ends have high transmittance when they are symmetrically by using a medium having low refractive index, and the medium used for high refractive index is TiO ₂ , ZnO, Ta _2. O ₅ , SrTiO ₃ , HfO ₂ , CeO ₂ , ZnS, etc., mainly ZnS is used, the refractive index is about 2.3 ~ 2.4.

Materials used as low refractive index media include SiO ₂ , MgF ₂ , NaF, LiF, CaF ₂ , AlF ₃ , Cryolite {AlF ₃ (NaF) ₃ }, and MgF ₂ is mainly used.

Meanwhile, the projection system 260 includes a scanner 261 and a projection lens 262, and projects the incident diffracted light onto the screen 270. That is, the projection system 260 focuses a diffraction beam having a predetermined diffraction coefficient incident through the Fourier filter system 250 on the screen 270 to form a spot.

According to the present invention as described above, when the desired wavelength is selected in the multiple beams incident on the color wheel, there is an effect of preventing light loss due to the small amount of empty space required between the planes.

In addition, according to the present invention, unlike the conventional funnel-shaped, cylindrical type by using the reflected light beam of the desired wavelength in the multiple beams incident on the color wheel does not require an overlapping portion has the effect of minimizing light loss have.

Herein, the present invention described above has been described with reference to preferred embodiments, but those skilled in the art will variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. And can be changed.

Claims (5)

A cylindrical filter portion sequentially coated with a film that reflects only light of a desired color on the surface and transmits the rest so as to selectively reflect only light of a desired color among multiple beams incident from the outside; A driving unit for rotating the filter unit; And A drum-type reflective color wheel comprising a mounting portion for mounting the filter portion in the drive unit. The method of claim 1, And a reflector reflecting the light transmitted through the center of the filter part to a point spaced apart from the path of the reflected light. A light source system for generating multiple beams; An illumination lens system which emits light by changing the light emitted from the light source into linear parallel light; In order to selectively reflect only light of a desired color among multiple incident lights in a cylindrical shape, a film that reflects only light of a desired color on the surface is sequentially coated. When multiple beams are incident from the illumination lens system, only light of a desired color is sequentially rotated. Color wheel system that reflects; A diffraction type optical modulator for modulating the reflected light emitted from the color wheel system to produce diffracted light having a plurality of diffraction coefficients; A Fourier filter system for passing diffracted light of a desired order in diffracted light having a plurality of diffraction coefficients emitted from the optical modulator; And And a projection system for projecting a diffracted light of a desired order filtered by the Fourier filter system onto a screen. The method of claim 3, wherein The color wheel system, A cylindrical filter portion sequentially coated with a film that reflects only light of a desired color on the surface and transmits the rest so as to selectively reflect only light of a desired color among multiple beams incident from the outside; A driving unit for rotating the filter unit; And Display device using a drum-type reflective color wheel comprising a mounting portion for mounting the filter portion in the drive unit. The method according to claim 3 or 4, The Fourier filter system, A Fourier lens for separating the diffracted light for each order from diffracted light having a plurality of diffraction coefficients incident from the diffractive optical modulator; And A display device using a drum-type reflective color wheel comprising a color discrimination filter for filtering the diffracted light incident from the Fourier lens.

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