CN1323311C - Color-variable pixel unit of optical interferometric display panel - Google Patents

Abstract

A color-changeable pixel unit of an optical interference display panel at least comprises: a first electrode; a second electrode, which is a movable electrode and is approximately parallel to the first electrode; and a plurality of supports located between the first electrode and the second electrode, wherein the deformation restoring force of the second electrode is adjusted by changing the distribution density of the supports, namely the deformation restoring force of the light reflection electrode is improved. When the distance between the supports is shortened or the distribution density is increased, the unit area strain of the light reflection electrode is relatively increased, and the stress generated by the light reflection electrode under the action of external force is increased. Therefore, when the external force disappears, the light reflection electrode can be successfully restored to the original state by the increased stress.

Description

The color-variable pixel unit of light interference type display panel

Technical field

The present invention relates to a kind of light interference type display panel, relate in particular to a kind of color-variable pixel unit of light interference type display panel.

Background technology

Flat-panel screens is owing to have little, the lightweight characteristic of volume, at the Portable display device, and very advantageous in the monitor market of using, little space.Flat-panel screens is now removed LCD (LiquidCrystal Display, LCD), organic electric exciting light-emitting diode (Organic Electro-LuminescentDisplay, OLED) and plasma display (Plasma Display Panel, PDP) or the like outside, a kind of plane display mode of light interference type that utilizes is suggested.

This display is formed by light interference type color-variable pixel unit array, its characteristic has low electric power power consumption, rapid answer (Response Time) and bistable state (Bi-Stable) characteristic in itself, the panel of display will be can be applicable to, particularly in the application of Portable (Portable) product, for example mobile phone (MobilePhone), PDA(Personal Digital Assistant), portable computer (Portable Computer) or the like.

See also the 5th, 835, No. 255 patents of the U.S., this patent has disclosed the adjustment assembly (Arrayof Modulation) of a visible light, is a color-variable pixel unit, is used as the usefulness of flat-panel screens.See also Fig. 1, Fig. 1 is the diagrammatic cross-section of existing color-variable pixel unit.Each color-variable pixel unit 100 comprises twice wall (Wall) 102 and 104, and 102,104 on twice wall is supported bystilt 106 and forms a chamber (Cavity) 108.The distance that the twice wall is 102,104, just the height ofchamber 108 isD.Wall 102 is a smooth incident electrode, has absorptivity, but the absorption portion visible light.104 on wall is a smooth reflecting electrode, utilizes driven can make it produce deformation.

Usually utilize the incident light source of white light as this color-variable pixel unit 100, the light that white light comprises various different wave lengths in the visible light spectrum scope (Wave Length represents with λ) is blended together.When incident light passeswall 102 and when entering in thechamber 108, only has the incident light of coincidence formula 1.1 medium wavelengths restriction to produce constructive interference and the output that is reflected incavity 108, wherein N is a natural number.In other words,

2D＝Nλ₁ (1.1)

When the height D ofchamber 108 satisfies incident light half-wavelength (λ₁During/2) integral multiple, can make this lambda1-wavelength λ₁In thischamber 108, produce constructive interference, and export this wavelength X₁Reflected light.At this moment, observer's eyes are observed along the direction of incidentlight incident wall 102, can see that wavelength is λ₁Reflected light, therefore, color-variable pixel unit 100 is in "open" state.

Fig. 2 is the diagrammatic cross-section of color-variable pixel unit 100 after adding voltage among Fig. 1.Please refer to Fig. 2, under the driving of voltage,wall 104 can produce deformation because of electrostatic attraction, sinks to the direction of wall 102.At this moment, the distance that the twice wall is 102,104, just the height ofchamber 108 is d, and this d can equal zero.

That is to say that the D in the formula 1.1 will replace with d, in the wavelength of all light, the wavelength (λ of coincidence formula 1.1 is only arranged in the incident light₂) can incavity 108, produce constructive interference, the reflection ofprocess wall 104 penetrateswall 102 and exports.In this color-variable pixel unit 100, it is λ thatwall 102 is designed to wavelength₂Light have higher absorptivity, so all light in the incident light are all by filtering, the observer for observing along the direction of incidentlight incident wall 102 will can not see that any light is reflected out.Therefore, this moment color-variable pixel unit 100 is in "off" state.

As mentioned above, under the driving of voltage,wall 104 can produce deformation because of electrostatic attraction, sinks to the direction ofwall 102, makes this color-variable pixel unit 100 switch to "off" state by "open" state.And when color-variable pixel unit 100 will switch to "open" state by "off" state, then must remove earlier in order to drive the voltage ofwall 104 deformation, then, deformation restoring force own paddles one's own canoe, thewall 104 that loses the electrostatic attraction effect can revert to the original state as Fig. 1, makes this color-variable pixel unit 100 present a "open" state.

Wall 104 is a smooth reflecting electrode, is generally a metallic film, and the size of its deformation restoring force is decided by the size of its membrane stress.Its deformation restoring force is big more when the membrane stress of thewall 104 of metallic film is big more, that is to say, it is subjected to the big more wall ofmembrane stress 104 external force and causes the restoring force after the deformation good more, and the situation of virgin state can not take place to return to more.Therefore, the existing method of adjusting the deformation restoring force size ofwall 104 is the composition by the alloy that changeswall 104, utilizes the different membrane stress sizes of different-alloy, adjusts the deformation restoring force ofwall 104.

Yet, when utilizing the bigger metallic film of membrane stress to makewall 104, the time regular meeting because its membrane stress is excessive, and the problem that causes this metallic film in coating process or subsequent manufacturing processes, to peel off.And, also can and then have influence on the performance of its fiduciary level for the adjustment ofwall 104.

In summary, need a kind of color-variable pixel unit, the color-variable pixel unit that can utilize the little metallic film manufacturing of membrane stress to have high deformation restoring force, above-mentioned metallic film peels off and the problem of fiduciary level to improve.

Summary of the invention

At above-mentioned defective, fundamental purpose of the present invention is, a kind of color-variable pixel unit of light interference type display panel is provided, and above-mentioned metallic film peels off and the problem of fiduciary level to improve.

Another object of the present invention is to, a kind of color-variable pixel unit of light interference type display panel is provided, the color-variable pixel unit that can select the metallic film manufacturing of low membrane stress to have high deformation restoring force.

Another purpose of the present invention is, a kind of color-variable pixel unit of light interference type display panel is provided, and adjusts the wherein distribution density of stilt, to improve the wherein unit area deformation quantity of light reflecting electrode.

According to above-mentioned purpose of the present invention, a kind of color-variable pixel unit of light interference type display panel is proposed, comprise at least: one first electrode; One second electrode is a movable electrode, and becomes to be arranged in parallel approximately with this first electrode; And a plurality of stilts, between this first electrode and this second electrode, wherein adjust the deformation restoring force of this second electrode by the distribution density that changes these stilts.

The spacing of the present invention by changing the stilt in the color-variable pixel unit with and the density that distributes, to improve the deformation restoring force of light reflecting electrode wherein.When the hypotelorism of stilt or distribution density improved, the unit area dependent variable of light reflecting electrode also improved relatively, and this time reflecting electrode is subjected to the external force effect and the stress that produces also increases thereupon.Therefore, after external force disappeared, the stress of this increase just can make the light reflecting electrode successfully return to original state.

According to a preferred embodiment of the present invention, stilt is a plurality of support columns, has the gap between support column and another support column, and forms array shape arrangement and cross a zone of action.The scope of the distribution density of this support column is between every square millimeter 225 to every square millimeter 2500.According to another preferred embodiment of the present invention, the preferred range of the distribution density of this support column is between every square millimeter 400 to every square millimeter 2500.

The material of stilt generally can the usability luminescent material in the present invention, for example photoresistance, or the polymeric material of non-sensitization, for example polyester or poly-vinegar or the like.According to another preferred embodiment of the present invention, be applicable in the present invention as the material that forms stilt to comprise positive photoresistance, negative photoresistance, various polymkeric substance, for example, acrylic (Acrylic) resin, epoxy resin or the like.Change the distribution density of the stilt in the variable pixel components, can adjust the deformation restoring force of light reflecting electrode significantly, make variable pixel components of the present invention can utilize the little metallic film of membrane stress to be used as the light reflecting electrode, and avoid prior art in order to reach high deformation restoring force, and the metallic film that is caused when using the big metallic film of membrane stress peels off and the problem of fiduciary level.

In addition, the present invention also can reduce in order to take into account the research and development time and the manufacturing cost of the big and incrust metallic film of membrane stress, uses the present invention and cooperates existing and low-cost metallic film can obtain enough deformation restoring forces and manipulates for color-variable pixel unit.

Brief Description Of Drawings

Below in conjunction with accompanying drawing,, will make technical scheme of the present invention and other beneficial effects apparent by detailed description to preferred embodiment of the present invention.

In the accompanying drawing,

Fig. 1 is the diagrammatic cross-section of existing color-variable pixel unit;

Fig. 2 is the diagrammatic cross-section of color-variable pixel unit after adding voltage among Fig. 1;

Fig. 3 is the vertical view of the color-variable pixel unit of a preferred embodiment of the present invention; And

Fig. 4 A figure to Fig. 4 B is the manufacture method synoptic diagram of the color-variable pixel unit of a preferred embodiment of the present invention.

Embodiment

Hereinafter, will describe the present invention in detail.

The metallic film that has color-variable pixel unit now peels off and the problem of fiduciary level in order to improve, and the present invention proposes a kind of color-variable pixel unit of light interference type display panel.

Feature of the present invention is, comprise at least the spacing that changes the stilt in the color-variable pixel unit with and the density that distributes, to improve the deformation restoring force of light reflecting electrode wherein.When the hypotelorism of stilt or distribution density improved, the unit area dependent variable of light reflecting electrode also improved relatively, and this time reflecting electrode is subjected to the external force effect and the stress that produces also increases thereupon.Therefore, after external force disappeared, the stress of this increase just can make the light reflecting electrode successfully return to original state.So, needn't use the big material of membrane stress to make the light reflecting electrode, by adjusting the distribution density of stilt, can improve the deformation restoring force of light reflecting electrode significantly, the metallic film that can solve existing color-variable pixel unit effectively peels off and the problem of fiduciary level.

Fig. 3 is the vertical view of the color-variable pixel unit of a preferred embodiment of the present invention.As shown in Figure 3, color-variable pixel unit 300 hasseparation structure 302, is positioned at relative both sides.And in this embodiment, the stilt of color-variable pixel unit 300 is a plurality ofsupport columns 306, represents with square in Fig. 3, yet in actual applications, can optionally be designed to arbitraryshape.Separation structure 302 andsupport column 306 are arranged between light incident electrode and the light reflecting electrode (wall 102 of Fig. 1 andwall 104).Have spacing 1 betweensupport column 306 and anothersupport column 306, and form array shape arrangement and cross a zone ofaction 312.

Feature of the present invention be the spacing 1 that changes thestilt 306 in the color-variable pixel unit 300 with and distribution density, to improve the deformation restoring force of light reflecting electrode wherein.

According to one embodiment of the invention, color-variable pixel unit 300 is of a size of 204 μ m * 204 μ m, and 306 one-tenth arrays of support column are arranged in wherein.When the number ofsupport column 306 was 3 * 3, the spacing 1 ofsupport column 306 was about 50 μ m, and the deformation restoring force of this time reflecting electrode is little.Under same condition, when the number ofsupport column 306 was 4 * 4, the spacing 1 ofsupport column 306 was about 40 μ m, and can see the bright dipping reflecting electrode significantly this moment after deformation, the situation that its deformation restoring force increases before.And when the number ofsupport column 306 was 5 * 5, the spacing 1 ofsupport column 306 was about 30 μ m, and the speed of recovering after the deformation of this time reflecting electrode is quicker.Below the above-mentioned condition of arrangement is in table one.

Table one: the comparison of the support column number of color-variable pixel unit.

The number of support column (individual)	The spacing of support column (μ m)	Area size (the μ m in zone 3122)	Unit area density (1/mm2)
				3×3	50	2500	225
4×4	40	1600	400
				5×5	30	900	625

By can finding out in the table one, when the number ofsupport column 306 is many more, its spacing 1 is more little, and the area in thezone 312 that is surrounded is also more little, andsupport column 306 numbers in the unit area are also many more, and promptly its unit area density is big more.According to another preferred embodiment of the present invention, after the elastic limit of consideration light reflecting electrode and the conditions such as aperture opening ratio of variable pixel components, the spacing 1 ofsupport column 306 can be contracted to 20 μ m, the number of thesupport column 306 in its unit area, be its unit area density, can reach every square millimeter of 2500 (2500mm^-2).Light reflecting electrode in the color-variable pixel unit 300 is subjected to 306 supports of maximum support columns in per unit area at this moment, so its deformation restoring force is also best.

It should be noted that in this embodiment stilt is support column independently, yet, the stilt of other type, for example latticed interconnective stilts such as (grid) also can apply among the present invention, is not subjected to the restriction of present embodiment.The invention is characterized in to utilize to change the density that stilt distributed, control its support for the start area of light reflecting electrode, the density of stilt is big more in unit area, and then the deformation restoring force of per unit area is also big more.That is to say, be example with above-mentioned latticed stilt, and when the size of the grid that it comprised was thin more, then the deformation restoring force of per unit area also improved relatively.

Below utilize Fig. 4 A and Fig. 4 B to explain manufacture method of the present invention.Please refer to Fig. 4 A, on a substrate, for example transparency carrier 409, form earlier first electrode 410 and sacrifice layer 411 in regular turn.Sacrifice layer 411 can adopt material transparent, for example dielectric material, or opaque material, and for example metal material, polysilicon or amorphous silicon adopt amorphous silicon as the material that forms sacrifice layer 411 in the present embodiment.

Then, in first electrode 410 and sacrifice layer 411, form opening 412 again and form stilt 406 in it, for example in first electrode 410 and sacrifice layer 411, form opening 412 with a micro image etching procedure to be applicable to.Feature of the present invention is to form opening 412 with a predetermined density, utilizes to change the density that opening 412 is distributed, to adjust the deformation restoring force of color-variable pixel unit.

Then, form a material layer (not expression among Fig. 4 A) to fill up opening 412 at sacrifice layer 411.Material layer is applicable to the usefulness that forms stilt 406, generally can the usability luminescent material, and for example photoresistance, or the polymeric material of non-sensitization, for example polyester or poly-vinegar or the like.If use non-photosensitive material to form material layer, then need a micro image etching procedure on material layer, to define stilt 406.Form material layer with photosensitive material in the present embodiment, therefore only need with a micro-photographing process patterned material layer.

Then, form second electrode 414 on sacrifice layer 411 and stilt 406.At last, please refer to Fig. 4 B, with structure release etch processing procedure (Release Etch Process), for example a plasma etching processing procedure removes the sacrifice layer 411 shown in Fig. 4 A and formation chamber 416 (position of sacrifice layer 411).The height D of chamber 416 is the thickness of sacrifice layer 411.The plasma etching processing procedure to be to contain fluorine-based or the etchant of chloro, for example etchants such as carbon tetrafluoride, boron chloride, Nitrogen trifluoride or sulfur hexafluoride etc. for precursor to produce a plasma etching sacrifice layer 411.

Be applicable in the present invention as the material that forms stilt 406 to comprise positive photoresistance, negative photoresistance, various polymkeric substance, for example, acrylic (Acrylic) resin, epoxy resin or the like.

Change the density of the stilt in the variable pixel components, can adjust the deformation restoring force of light reflecting electrode significantly, make variable pixel components of the present invention can utilize the little metallic film of membrane stress to be used as the light reflecting electrode, and avoid existing in order to reach high deformation restoring force, and the metallic film that is caused when using the big metallic film of membrane stress peels off and the problem of fiduciary level.In addition, the present invention also can reduce in order to take into account the research and development time and the manufacturing cost of the big and incrust metallic film of membrane stress, uses the present invention and cooperates existing and low-cost metallic film can obtain enough deformation restoring forces and manipulates for color-variable pixel unit.

Be understandable that; for the person of ordinary skill of the art; can make other various corresponding changes and distortion according to technical scheme of the present invention and technical conceive, and all these changes and distortion all should belong to the protection domain of accompanying Claim of the present invention.

Claims (9)

Translated fromChinese

1、一种光干涉式显示面板的可变色像素单元，其特征在于，包含：1. A variable color pixel unit of an optical interference display panel, characterized in that it comprises:一第一电极；a first electrode;一第二电极，为一可动电极，并与该第一电极成平行排列；以及a second electrode, being a movable electrode, arranged in parallel with the first electrode; and多个支撑物，位于该第一电极与该第二电极之间，其中通过改变这些支撑物的分布密度调整该第二电极的形变恢复力。A plurality of supports are located between the first electrode and the second electrode, wherein the deformation recovery force of the second electrode is adjusted by changing the distribution density of the supports.2、根据权利要求1所述的可变色像素单元，其特征在于，当这些支撑物为多个支撑柱时，这些支撑柱的分布密度为每单位面积中这些支撑柱的数目。2. The color-changing pixel unit according to claim 1, wherein when the supports are a plurality of support columns, the distribution density of the support columns is the number of the support columns per unit area.3、根据权利要求2所述的可变色像素单元，其特征在于，该分布密度的范围介于每平方毫米225个至每平方毫米2500个之间。3. The color-variable pixel unit according to claim 2, wherein the distribution density ranges from 225 to 2500 per square millimeter.4、根据权利要求2所述的可变色像素单元，其特征在于，该分布密度的范围介于每平方毫米400个至每平方毫米2500个之间。4. The color-variable pixel unit according to claim 2, wherein the distribution density ranges from 400 per square millimeter to 2500 per square millimeter.5、根据权利要求1所述的可变色像素单元，其特征在于，这些支撑物为多个网格状支撑物。5. The color-changing pixel unit according to claim 1, wherein the supports are a plurality of grid-like supports.6、根据权利要求1所述的可变色像素单元，其特征在于，这些支撑物的材料为感光材料或非感光的聚合物材料。6. The color-changing pixel unit according to claim 1, wherein the materials of the supports are photosensitive materials or non-photosensitive polymer materials.7、根据权利要求1所述的可变色像素单元，其特征在于，这些支撑物的材料为光阻。7. The color-changing pixel unit according to claim 1, wherein the material of the supports is photoresist.8、根据权利要求1所述的可变色像素单元，其特征在于，这些支撑物的材料为聚酯或聚醯。8. The color-changing pixel unit according to claim 1, characterized in that the materials of the supports are polyester or polyamide.9、根据权利要求1所述的可变色像素单元，其特征在于，这些支撑物的材料为亚克力树酯或环氧树酯。9. The color-changing pixel unit according to claim 1, characterized in that, the materials of the supports are acrylic resin or epoxy resin.

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