CN101907801B - Flat panel display based on tunable optical filter - Google Patents

Abstract

A flat panel display based on an adjustable optical filter in the field of flat panel display, comprising: a backlight module, a variable optical modulation device, a display optimization device and a protective case, wherein: the variable optical modulation device includes: reflection/transmission Mirror, transparent substrate and several adjustable filters, the adjustable filter includes three filter sub-units, each filter sub-unit includes: upper reflector, lower reflector, upper electrode, lower electrode and voltage sensitive material film. In the present invention, the adjustable filter can adjust the central wavelength of the pass band and the stop band according to the requirement of display, so as to achieve the purpose of modulating the color and light intensity of the backlight. Due to the introduction of multiplexing and replacement of the polarizer and color filter structure in the traditional TFT-LCD structure, the energy utilization rate is improved, the integration of panel devices can be greatly improved, and the thickness and cost of the panel can be reduced.

Description

Flat panel display based on tunable optical filter

technical field

The invention relates to a device in the technical field of image display, in particular to a flat panel display based on an adjustable optical filter.

Background technique

Flat panel display is a kind of display technology compared with the huge body of traditional picture tube display. big pillar. In the ten years after entering the 21st century, liquid crystal display technology has developed rapidly, and it has completely surpassed traditional display products based on cathode ray tubes (CRT) in the two major application fields of monitors and televisions. Among the current flat panel display products, liquid crystal displays occupy an absolute dominant position. In liquid crystal display (LCD) technology, the most mature is thin film transistor display technology (TFT-LCD).

The principle of thin film transistor liquid crystal display (TFT-LCD) is to use liquid crystals to change the polarization state of incident light to control the passage of light. A traditional TFT-LCD panel is mainly composed of two parts: a backlight module and a liquid crystal panel. The function of the backlight module is to provide sufficient intensity and evenly distributed light to the liquid crystal panel, and its composition includes a light source, a light guide plate, a reflector plate, an optical diffusion film, and a prism anti-reflection film. The main function of the liquid crystal panel is to control the light intensity of different colors of light. Its structure includes two front and rear orthogonal polarizers, a glass substrate, a TFT circuit layer, a liquid crystal alignment layer, a liquid crystal layer, a color filter, etc. The principle is through The TFT circuit applies a voltage signal on the liquid crystal layer to control the polarization state of the linearly polarized light emitted from the front polarizer, thereby controlling the amount of light emitted from the rear polarizer. Absorptive color filters can realize the intensity control of different colors of light.

After searching the existing literature, it is found that the Chinese application number is: 200510118113.2, and the name is: array substrate, color filter substrate, liquid crystal display and display device. This technology uses color filters to modulate the color of the backlight to make different The color pixels only display one of the three colors of red, green, and blue; two polarizing layers are used to modulate the light intensity of the backlight, so that different color pixels produce different gray scales. Since each pixel is composed of three color pixels of red, green, and blue, and the size of the pixel is extremely small, the human eye will perform additive color mixing on it when observing it, and then produce the required color. However, this technology has some obvious deficiencies in energy utilization: one is that the traditional absorbing polarizer that produces linearly polarized light will cause nearly 1/2 of the light absorption loss due to the use of the polarization state of light to modulate the light intensity; the other is that Since an absorbing color filter is used to filter out other colors and pass through a specific color, it will cause 2/3 of the light to be absorbed and lost. Therefore, the maximum theoretical light energy utilization efficiency of this technology does not exceed 16.67%. If factors such as material absorption and interface reflection are considered, the actual light energy utilization efficiency generally does not exceed 10%, which will cause great waste of energy.

Contents of the invention

The object of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide a flat panel display based on an adjustable optical filter. The invention has the functions of light intensity modulation and color modulation at the same time, can eliminate the loss caused by polarizers and color filters in traditional TFT-LCDs, and can greatly improve the integration of panel devices, simplify the display structure, and reduce the size of the panel. thickness and reduce costs.

The present invention is achieved through the following technical solutions:

The invention comprises: a backlight module, a variable optical modulation device, a display optimization device and a protective case, wherein: the backlight module is arranged at the bottom of the protective case, the variable optical modulation device is arranged in parallel on the upper part of the backlight module, and the display optimization device Parallel to the upper part of the variable optical modulation device, the distance between the bottom of the variable optical modulation device and the top of the backlight module is L ₁ , and the distance between the bottom of the display optimization device and the top of the variable optical modulation device is L ₂ .

The value range of L ₁ is: 0<L ₁ ≤1mm.

The value range of L ₂ is: 0<L ₂ ≤1mm.

The protective shell is an open rectangular parallelepiped protective shell.

The backlight module provides a variable optical modulation device with a narrow light divergence angle, and the spectrum of its outgoing light is required to cover the visible light range, and its spectrum has a peak distribution near the red, green and blue wavelengths. The backlight of the device The mode is direct type or side incidence type.

When the backlight module adopts a direct backlight, it includes: a bottom reflector, four side reflectors, a light source array, a first diffusion film and a prism film, wherein: the bottom reflector is arranged at the bottom of the protective case, and the side reflector It is fixed on the side of the protective case and connected vertically to the bottom reflector. The light source array is arranged on the bottom reflector. The first diffusion film is arranged on the light source array and connected to the tops of the four side reflectors respectively. The prism film is arranged on the first on the diffusion membrane.

When the backlight module adopts a side-incidence backlight, it includes: a bottom reflector, a side reflector, a side light source, five light source reflectors, a light guide plate, a first diffusion film and a prism film, wherein: the bottom reflector is arranged on At the bottom of the protective case, the light guide plate is set on the bottom reflector, the side reflector is fixed on the side of the protective case where the light source cannot be coupled and is vertically connected to the bottom reflector, the side light source is close to one side of the light guide plate, and the first diffusion film Set on the light guide plate, the prism film is set on the first diffusion film, the first diffusion film and the prism film completely cover the light guide plate, five light source reflection plates are set around the side light source and form a cuboid with only one opening surface .

The variable optical modulation device includes: reflection/transmission mirror, transparent substrate and several adjustable filters, wherein: the reflection/transmission mirror is placed in parallel on the upper part of the backlight module and the distance from the top of the backlight module is L ₁ , The transparent base is arranged on the reflection/transmission mirror, the adjustable filter is placed on the transparent base in parallel and the distance from the top of the transparent base is L ₃ , and the adjustable filters are horizontally connected in turn.

The reflection/transmission mirror is a multi-layer film structure.

The value range of L ₃ is between several micrometers and several millimeters.

The transparent substrate is glass, indium tin oxide coated glass, plastic or acrylic material.

The adjustable filter includes three filtering subunits, each filtering subunit includes: an upper reflector, a lower reflector, an upper electrode, a lower electrode and a voltage-sensitive material film, wherein: the lower electrode, the lower reflector, The voltage-sensitive material film, the upper reflector, and the upper electrode are placed close to each other in order from bottom to top, and the lower electrode is arranged on the transparent substrate with a distance of L ₃ from the top of the transparent substrate.

The upper electrode and the lower electrode are indium tin oxide, gold, silver or aluminum.

The upper reflector and the lower reflector are metal mirrors, dielectric mirrors or distributed Bragg mirrors with a height ranging from 10nm to 500nm.

The voltage-sensitive material thin film is high polymer containing fluorine or piezoelectric ceramics.

The display optimization device includes: a second diffusion film and an anti-reflection film, wherein: the second diffusion film is placed in parallel on the variable optical modulation device and the distance from the top of the variable optical modulation device is L ₂ , and the anti-reflection film placed on the second diffuser membrane.

Compared with the prior art, the beneficial effect of the present invention is that by directly modulating the color and light intensity of the backlight, the polarization loss in the traditional TFT-LCD light intensity modulation and the color filter in the color modulation are completely eliminated. loss, and realize the recycling of reflected light, the maximum theoretical energy utilization efficiency of the present invention is 50%, according to the current existing technology, the actual utilization efficiency is about 33%, compared with the existing TFT-LCD display, the energy efficiency is improved to more than 3 times.

Description of drawings

Fig. 1 is the device structure schematic diagram of embodiment 1;

Among them: 1 is the protective shell, 2 is the bottom reflector, 3 is the side reflector, 4 is the light source array, 5 is the first diffusion film, 6 is the prism film, 7 is the reflection/transmission mirror, 8 is the transparent substrate, 9 is The lower reflector, 10 is the lower electrode, 11 is the voltage sensitive material thin film, 12 is the upper electrode, 13 is the upper reflector, 14 is the second diffusion film, and 15 is the anti-reflection film.

Fig. 2 is the schematic diagram that transmission spectrum changes with light source wavelength or voltage in embodiment 1;

Among them: (a) is a schematic diagram of the change of the transmission spectrum when the wavelength of the light source is changed; (b) is a schematic diagram of the change of the transmission spectrum when the voltage is changed.

Fig. 3 is the device structure schematic diagram of embodiment 2;

Among them: 1 is the protective shell, 2 is the bottom reflector, 3 is the side reflector, 5 is the first diffusion film, 6 is the prism film, 7 is the reflective/transmissive mirror, 8 is the transparent substrate, 9 is the lower reflector, 10 11 is the lower electrode, 11 is the voltage-sensitive material film, 12 is the upper electrode, 13 is the upper reflector, 14 is the second diffusion film, 15 is the anti-reflection film, 16 is the side light source, 17 is the light source reflection plate, 18 is the light guide plate .

Detailed ways

The device of the present invention is further described below in conjunction with the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following Example.

Example 1

As shown in Figure 1, this embodiment includes: a backlight module, a variable optical modulation device, a display optimization device and a protective case 1, wherein: the backlight module is arranged at the bottom of the protective case 1, and the variable optical modulation device is arranged in parallel The upper part of the backlight module, the display optimization device is arranged in parallel on the upper part of the variable optical modulation device, the distance between the bottom of the variable optical modulation device and the top of the backlight module is 0.8mm, the bottom of the display optimization device and the variable optical modulation device The top distance is 0.8mm.

The protective case 1 is an open rectangular parallelepiped protective case.

The backlight module provides the variable optical modulation device with a narrow light divergence angle, and the spectrum of the emitted light is required to cover the visible light range, and its spectrum has a peak distribution around the red, green and blue wavelengths. In this embodiment The backlight module adopts a direct backlight, including: a bottom reflector 2, four side reflectors 3, a light source array 4, a first diffusion film 5 and a prism film 6, wherein: the bottom reflector 2 is arranged at the bottom of the protective case 1, The side reflector 3 is fixed on the side of the protective case 1 and is vertically connected to the bottom reflector 2, the light source array 4 is arranged on the bottom reflector 2, and the first diffusion film 5 is arranged on the light source array 4 and connected to the four side reflectors respectively. The tops of 3 are connected, and the prism film 6 is arranged on the first diffusion film 5 .

The variable optical modulation device is used to realize a variable optical bandpass filter, and its passband position is set near the wavelengths of red, green and blue. By moving the passband position of the variable optical filter, not only can the light of a specific color be filtered out from the light source, but also because the light emitted by the backlight module has a peak distribution near the red, green and blue wavelengths (that is, at different wavelengths have different light intensities), so that the size of the light intensity of a specific color can be controlled. The device includes: reflection/transmission mirror 7, transparent substrate 8 and 1200*800 adjustable filters, wherein: reflection/transmission mirror 7 is placed in parallel on the upper part of the backlight module and the distance from the top of the backlight module is 0.8mm, The transparent substrate 8 is arranged on the reflective/transmissive mirror 7, the tunable filter is placed on the transparent substrate 8 in parallel and the distance from the top of the transparent substrate 8 is 6 microns, and the tunable filters are respectively connected horizontally in sequence.

The transparent substrate 8 in this embodiment is glass.

The tunable filter includes three filtering subunits, and each filtering subunit includes: an upper reflector 13, a lower reflector 9, an upper electrode 12, a lower electrode 10 and a voltage sensitive material film 11, wherein: the lower electrode 10. The lower reflector 9, the voltage-sensitive material film 11, the upper reflector 13, and the upper electrode 12 are placed close to each other in order from bottom to top. The lower electrode 10 is arranged on the transparent substrate 8 and the distance from the top of the transparent substrate 8 is 6 microns.

In this embodiment, a silver mirror with a height of 20nm realizes the functions of the upper electrode 12 and the upper reflector 13 at the same time, and another silver mirror with a height of 20nm realizes the functions of the lower electrode 10 and the lower reflector 9 simultaneously, and the voltage sensitive material film 11 It is a fluorine-containing high polymer.

In this embodiment, the thickness of the voltage-sensitive material film 11 in the first filtering subunit is 330nm (corresponding to filtering red light), and the thickness of the voltage-sensitive material film 11 in the second filtering subunit is 290nm (corresponding to filtering green light), The voltage-sensitive material thin film 11 in the third filtering subunit has a thickness of 240 nm (corresponding to filtering blue light).

In this embodiment, two silver mirrors with a height of 20nm and the voltage-sensitive material film 11 form a Fabry-Perot cavity together, and the central wavelength λ of the transmission spectrum of the Fabry-Perot cavity satisfies:

$\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Z\&pi;nl</span>}}{\mathrm{<span\; class="notranslate">\; m\&pi;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&phi;</span>}}<span\; class="notranslate">\; ,</span>$

Wherein: n is the refractive index of the voltage sensitive material thin film 11, l is the thickness of the voltage sensitive material thin film 11, m is the interference series, φ is the phase mutation after reflection, and Z is a positive integer.

The display optimization device includes: a second diffusion film 14 and an anti-reflection film 15, wherein: the second diffusion film 14 is placed in parallel on the variable optical modulation device and the distance from the top of the variable optical modulation device is 0.8 mm, The anti-reflection film 15 is provided on the second diffusion film 14 .

The working process of this embodiment: Since each tunable filter has three kinds of voltage-sensitive material films 11 with different reference heights, it can transmit red, green and blue light respectively and reflect light of other wavelengths at the same time. After voltage-driving the voltage-sensitive material thin film 11 of each height, the height or refractive index of the voltage-sensitive material thin film 11 will change, thereby changing the central wavelength of the transmission spectrum. As shown in Figure 2(a), if the selected light source has a distribution similar to mountain peaks in the spectrum of red, green and blue, that is, the center is high and the sides are low, when the transmission spectrum of the adjustable filter is near a certain color light, it can be selected A colored light shines through. And when the voltage applied to both ends of the voltage-sensitive material changes, the transmission spectrum will move accordingly, as shown in Figure 2(b), and the transmission amount can also be controlled to achieve the function of modulating the light intensity.

The specific advantage of this embodiment: Compared with the traditional method of polarization modulation of light intensity, this embodiment uses an optical filter to directly modulate the light intensity. Eliminates the 50% energy loss that occurs when polarizing a light source when polarization modulation is applied. At the same time, compared with the traditional color selection method of the absorption color filter, this embodiment uses the optical filter to directly select the color, and reflects the unnecessary color components out of the modulation module and through the reflection/transmission mirror It is reused. Eliminates 67% of the energy lost by color filters when color filters are applied.

In this embodiment, under the condition of meeting the requirement of normal display, the energy utilization efficiency of the entire display reaches 33.4%, which is 3-4 times that of the thin film transistor liquid crystal display.

Example 2

As shown in Figure 3, the difference between this embodiment and Embodiment 1 is that when the backlight module adopts the side-incidence type backlight, it includes: a bottom reflector 2, a side reflector 3, a side light source 16, and five light source reflectors. Plate 17, light guide plate 18, first diffusion film 5 and prism film 6, wherein: the bottom reflector 2 is arranged on the bottom of the protective case 1, the light guide plate 18 is arranged on the bottom reflector 2, and the side reflector 3 is fixed on the light source coupling The side of the protective case 1 is not visible and is vertically connected to the bottom reflector 2, the side light source 16 is close to one side of the light guide plate 18, the first diffusion film 5 is arranged on the light guide plate 18, and the prism film 6 is arranged on the first diffusion film. 5, the first diffuser film 5 and the prism film 6 completely cover the light guide plate 18, and five light source reflection plates 17 are arranged around the side light source 16 and form a cuboid with only one open surface.

In this embodiment, the transparent substrate 8 is acrylic.

In this embodiment, the upper electrode 12 and the lower electrode 10 are all silver with a height of 1 micron, the upper reflector 13 and the lower reflector 9 are all silver with a height of 40nm, and the voltage sensitive material film 11 is piezoelectric ceramics, wherein: the first The thickness of the voltage-sensitive material thin film 11 in a filtering subunit is 4620nm (corresponding to filter red), the thickness of the voltage-sensitive material thin film 11 in the second filtering subunit is 4060nm (for filtering green), and the thickness of the third filtering subunit The thickness of the voltage sensitive material thin film 11 is 3360nm (corresponding to filter blue color).

In this embodiment, the upper reflector 13 , the lower reflector 9 and the voltage-sensitive material film 11 together form a Fabry-Perot cavity, and its working principle is the same as that of the first embodiment.

Compared with Embodiment 1, the thickness of the entire display is greatly reduced in this embodiment due to the use of the side light source 16 .

Claims (10)

1. flat-panel monitor based on tunable optical filter comprises: backlight module, variable optical modulating device, display optimization device and containment vessel, it is characterized in that, and backlight module is arranged on the bottom of containment vessel; The variable optical modulating device, be also display panel, and the top that is set in parallel in backlight module can be directly used in the image demonstration after to backlight the modulation; The display optimization device is set in parallel in the top of variable optical modulating device only for the light travel direction to from the outgoing of variable optical modulating device or the correction of angle as servicing unit; The distance at the bottom of variable optical modulating device and the top of backlight module is L ₁, the distance at the top of the bottom of display optimization device and variable optical modulating device is L ₂

Described variable optical modulating device comprises: reflection/transmission mirror, transparent substrates and some tunable optical filters, wherein: the reflection/transmission mirror is parallel to be placed on the top of backlight module and to be L with the distance at backlight module top ₁, transparent substrates is arranged on the reflection/transmission mirror, and parallel being placed on transparent substrates and with the distance at transparent substrates top of tunable optical filter is L ₃, between tunable optical filter, level is connected successively;

Described L<sub TranNum="148">1</sub>Span be: 0<L<sub TranNum="149">1</sub>≤ 1mm;

Described L<sub TranNum="151">2</sub>Span be: 0<L<sub TranNum="152">2</sub>≤ 1mm;

Described L ₃Span be between several microns to several millimeters;

In this display, the spectrum of backlight module emergent light has the peak shape and distributes near the redgreenblue wavelength, and the frequency spectrum of tunable optical filter has transmission peaks at visible light wave range, the centre wavelength wavelength of the centre wavelength at its spectral transmission peak and emergent light spectrum is complementary, therefore, during the work of this display, the centre wavelength at the projection peak by mobile tunable optical filter is controlled the light intensity magnitude of particular color; The tunable optical filter structure had due to this display is array format, therefore, " pixel " in the direct corresponding classic flat-plate display structure of each tunable optical filter, can independently directly modulate the light intensity and the color that show as single " pixel " on panel.

2. the flat-panel monitor based on tunable optical filter according to claim 1, is characterized in that, the mode backlight of described backlight module is straight-down negative or side incident-type.

3. the flat-panel monitor based on tunable optical filter according to claim 1 and 2, it is characterized in that, described backlight module adopts direct-type backlight, comprise: bottom reflecting plate, four offside reflection plates, array of source, the first diffusion barrier and prism film, wherein: bottom reflecting plate is arranged at the bottom of containment vessel, the offside reflection plate is fixed on the side of containment vessel and is connected with bottom reflecting plate is vertical, array of source is arranged on bottom reflecting plate, the first diffusion barrier is arranged on array of source and with the top of four offside reflection plates, is connected respectively, prism film is arranged on the first diffusion barrier.

4. the flat-panel monitor based on tunable optical filter according to claim 1 and 2, it is characterized in that, described backlight module adopts the side incident-type backlight, comprise: bottom reflecting plate, the offside reflection plate, the side light source, five light source reflecting plates, light guide plate, the first diffusion barrier and prism film, wherein: bottom reflecting plate is arranged on the bottom of containment vessel, light guide plate is arranged on bottom reflecting plate, the offside reflection plate be fixed on light source coupling less than containment vessel side and with bottom reflecting plate is vertical, be connected, the side light source is close to a side of light guide plate, the first diffusion barrier is arranged on light guide plate, prism film is arranged on the first diffusion barrier, the first diffusion barrier and prism film cover light guide plate fully, five light source reflecting plates be arranged on the side light source around and form a rectangular parallelepiped that an opening surface is only arranged.

5. the flat-panel monitor based on tunable optical filter according to claim 1, is characterized in that, described transparent substrates is glass, indium oxide coating glass, plastics or acryl material.

6. the flat-panel monitor based on tunable optical filter according to claim 1, it is characterized in that, described tunable optical filter comprises three filtering subelements, each filtering subelement comprises: upper reflector, lower catoptron, top electrode, bottom electrode and voltage sensitive material film, wherein: bottom electrode, lower catoptron, voltage sensitive material film, upper reflector, top electrode are close to placement according to order from the bottom up, and bottom electrode is arranged on transparent substrates and with the distance at transparent substrates top and is L ₃.

7. the flat-panel monitor based on tunable optical filter according to claim 6, is characterized in that, described top electrode and bottom electrode are tin indium oxide, gold, silver or aluminium.

8. the flat-panel monitor based on tunable optical filter according to claim 6, is characterized in that, described upper reflector and lower catoptron are that altitude range is speculum, dielectric mirror or the distributed Bragg mirror of 10nm-500 μ m.

9. the flat-panel monitor based on tunable optical filter according to claim 6, is characterized in that, fluorine-containing high polymer or the piezoelectric ceramics of described voltage sensitive material film.

10. the flat-panel monitor based on tunable optical filter according to claim 1, it is characterized in that, described display optimization device comprises: the second diffusion barrier and anti-reflection film, wherein: the second diffusion barrier is parallel to be placed on the variable optical modulating device and to be L with the distance at the top of variable optical modulating device ₂, anti-reflection film is arranged on the second diffusion barrier.

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