Source: http://www.google.fr/patents/US7042625?hl=fr
Timestamp: 2013-05-18 08:21:30
Document Index: 54965837

Matched Legal Cases: ['art 720', 'art 720', 'arts 741', 'arts 741', 'arts 732', 'arts 741', 'arts 741', 'arts 732', 'art 732', 'arts 732', 'arts 741', 'arts 732', 'arts 732', 'arts 732']

Brevet US7042625 - Light modulator having digital micro blaze diffraction grating - Google�BrevetsRecherche Images Maps Play YouTube Actualit�s Gmail Drive Plus » Recherche avanc�e dans les brevets | Historique Web | Connexion Recherche avanc�e dans les brevets BrevetsDisclosed is a light modulator having a digital micro blaze diffraction grating. In the light modulator, a fine protrusion is formed on an edge of a lower surface of a diffraction member so that a reflective surface inclines due to the fine protrusion when the diffraction member is drawn downward....http://www.google.fr/patents/US7042625?utm_source=gb-gplus-shareBrevet US7042625 - Light modulator having digital micro blaze diffraction grating Num�ro de publicationUS7042625 B2Type de publicationOctroi Num�ro de demande11/171,635 Date de publication9 mai 2006 Date de d�p�t29 juin 2005 Date de priorit�8 oct. 2004Autre r�f�rence de publicationUS20060077532 InventeursYoon Joon ChoiSeung Heon HANYoon Shik HongDong Ho Shin Cessionnaire d'origineSamsung Electro-Mechanics Co., Ltd. Classification aux �tats-Unis359/292359/224.1359/573359/298359/291359/569359/295359/318359/566359/571 Classification internationaleG02B26/00 Classification coop�rativeG02B26/0808 Classification europ�enneG02B 26/08DR�f�rencesCitations de brevets (11) R�f�renc� par (5)Liens externesUSPTO Cession USPTO EspacenetLight modulator having digital micro blaze diffraction gratingUS 7042625 B2 R�sum� Disclosed is a light modulator having a digital micro blaze diffraction grating. In the light modulator, a fine protrusion is formed on an edge of a lower surface of a diffraction member so that a reflective surface inclines due to the fine protrusion when the diffraction member is drawn downward.
In the second elongate member 124C, a step profile 150 of the elongate member 124 is substituted by a flat surface 226 inclined at a blaze angle ( ).
SUMMARY OF THE INVENTION Therefore, the present invention has been made keeping in mind the above disadvantages occurring in the prior arts, and an object of the present invention is to provide a light modulator having a blaze diffraction grating, which has high reliability and low residual oscillation.
FIGS. 9A to 9H are sectional views, which are taken along the line C�C′ of FIG. 7B and show the fabrication of the digital micro blaze diffraction grating according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a detailed description will be given of the present invention, with reference to FIGS. 7A to 9H.
Referring to FIGS. 7A to 7E, the light modulator having the digital micro blaze diffraction grating according to the present invention comprises a substrate 710, a first lower electrode 720 a, a second lower electrode 720 b, a lower electrode connection part 720 c, supporting members 730 a, 730 a′, 730 b, 730 b′, and diffraction members 740 a�740 d. The first lower electrode 720 a is attached to an upper side of a first portion of the substrate 710, the second lower electrode 720 b is attached to an upper side of a second portion of the substrate 710, and the lower electrode connection part 720 c electrically connects the first lower electrode 720 a to the second lower electrode 720 b therethrough.
The diffraction members 740 a�740 d include first external parts 741 a�741 d, second external parts 741 a′�741 d′, and central parts 732 a�732 d. Furthermore, first ends of the first external parts 741 a�741 d of the diffraction members 740 a�740 d are attached to the first supporting members 730 a, 730 b, and the second external parts 741 a′�741 d′ are attached to the second supporting members 730 a′, 730 b′. Accordingly, the diffraction members 740 a�740 d are suspended on the substrate 710.
As well, the diffraction members 740 a�740 d are separated from and parallel to each other as shown in FIG. 7B, which illustrates the plane view of the light modulator having the digital micro blaze diffraction grating according to the present invention. They have reflective surfaces capable of reflecting incident light on upper sides thereof.
The central parts 732 a�732 d of the diffraction members 740 a�740 d have protrusions 742 a�742 d formed on lower surfaces thereof so that each protrusion is longitudinally provided on an edge of the lower surface of each central part.
Each of the protrusions 742 a�742 d, which is comprised of an extended hexahedral piece, is attached to a side edge of the lower surface of the central part 732 a �732 d of the diffraction member 740 a�740 d. In this regard, the protrusions 742 a�742 d are not in contact with the substrate 710, but suspended on the substrate. This is apparent in FIG. 7C which illustrates a front view of the light modulator having the digital micro blaze diffraction grating according to the present invention.
From FIG. 7D, which illustrates an exploded perspective view of the light modulator having the digital micro blaze diffraction grating according to the present invention, and FIG. 7E, it can be seen that the protrusions 742 a�742 d are attached to the central parts 732 a�732 d so that each protrusion is longitudinally provided on the edge of each central part.
FIGS. 8A and 8B illustrate diffraction. In FIGS. 8A and 8B, a voltage (Vo) is applied to the diffraction members 740 a, 740 b, but an electric potential is not applied to the diffraction members 740 c, 740 d (V=0 V). FIG. 8A is a sectional view taken along the line A�A′ of FIG. 7B, which shows the movement of the first external parts 741 a�741 d. Referring to FIG. 8A, if the voltage is applied to the lower electrodes 720 a, 720 b and the diffraction members 740 a, 740 b, the diffraction members 740 a, 740 b are drawn downward by an electrostatic force. At this time, the diffraction members 740 a, 740 b incline because of the protrusions 742 a, 742 b. This can be seen from FIG. 8B. In FIG. 8B, when the central parts 732 a, 732 b are drawn downward, the protrusions 742 a, 742 b come into contact with the substrate 710, thus edges of the central parts 732 a, 732 b, on which the protrusions 742 a, 742 b are not formed, come into contact with the substrate 710, thereby inclining the diffraction members 740 a, 740 b. With respect to this, if reflective surfaces of the central parts 732 a, 732 b of the diffraction members 740 a, 740 b incline at an angle of multiples of λ/4 when a wavelength of incident light is λ, diffraction occurs. In FIG. 8B, reference numeral 1 denotes incident light, and reference numeral 3 denotes diffracted light.
F = ɛ ⁢ ⁢ AV o 2 2 ⁢ d 2 Equation ⁢ ⁢ 1 wherein, ∈ is a dielectric constant of air between the lower electrode 720 and the diffraction members 740 a�740 d, A is an area to which the electrostatic force is applied, and d is a distance between the diffraction members 740 a �740 d and the lower electrode 720.
F = ɛ ⁢ ⁢ AV o 2 2 ⁢ d 2 = k ⁡ ( d o - d ) Equation ⁢ ⁢ 2 wherein, do is an initial value of d, that is, the distance when the voltage is not applied. From the above Equation, it can be seen that, when the voltage (Vo) is higher than a value calculated by the following Equation 3, in Equation 2, d is a negative number, which is impossible in practice. Therefore, when the voltage is applied at a level higher than the value calculated by Equation 3, instability occurs between the electrostatic electrodes, thus the diffraction members 740 a, 740 b come into contact with the insulating substrate 710 as shown in FIGS. 8A and 8B. With respect to this, as shown in FIG. 8A, the diffraction members 740 a, 740 b may be designed so as not to come into contact with the lower electrode 720 by appropriately controlling the rigidity thereof.
When light is radiated on the diffraction members 740 a, 740 b, the path difference between light beams reflected-from the diffraction members 740 a and 740 b is �, thus diffracted light 3 is formed. On the other hand, when light is radiated on the diffraction members 740 c, 740 d, only reflected light 2 is formed, without diffraction. As described above, in the light modulator having the micro blaze diffraction grating according to the present invention, the two or more diffraction members, to which the same electric potential is applied, are integrated into one diffraction unit (i.e. a pixel), and a plurality of diffraction units are further integrated, thus it is possible to produce a multichannel light modulator which is capable of generating digital optical signals of diffraction or reflection according to a driving signal.
V o = 4 ⁢ kd o 3 27 ⁢ ɛ ⁢ ⁢ A Equation ⁢ ⁢ 3 FIGS. 9A to 9H are sectional views, which are taken along the line C�C′ of FIG. 7B and show the fabrication of the digital micro blaze diffraction grating according to the present invention.
Citations de brevets Brevet cit� Date de d�p�t Date de publication D�posant TitreUS531136028 avr. 199210 mai 1994The Board Of Trustees Of The Leland Stanford, Junior UniversityMethod and apparatus for modulating a light beamUS603165230 nov. 199829 f�vr. 2000Eastman Kodak CompanyBistable light modulatorUS603805718 d�c. 199814 mars 2000Eastman Kodak CompanyMethod and system for actuating electro-mechanical ribbon elements in accordance to a data streamUS610811730 oct. 199822 ao�t 2000Eastman Kodak CompanyMethod of making magnetically driven light modulatorsUS64078511 ao�t 200018 juin 2002Cheetah Omni, LlcMicromechanical optical switchUS681305928 juin 20022 nov. 2004Silicon Light Machines, Inc.Reduced formation of asperities in contact micro-structuresUS682279731 mai 200223 nov. 2004Silicon Light Machines, Inc.Light modulator structure for producing high-contrast operation using zero-order lightUS682909215 ao�t 20017 d�c. 2004Silicon Light Machines, Inc.Blazed grating light valveUS682925826 juin 20027 d�c. 2004Silicon Light Machines, Inc.Rapidly tunable external cavity laserUS692227328 f�vr. 200326 juil. 2005Silicon Light Machines CorporationPDL mitigation structure for diffractive MEMS and gratingsUS200402465594 avr. 20039 d�c. 2004Taguchi AyumuLight reflection/diffraction device, light reflection/diffraction device array, and image display R�f�renc� par Brevet citant Date de d�p�t Date de publication D�posant TitreUS774222028 mars 200722 juin 2010Qualcomm Mems Technologies, Inc.Microelectromechanical device and method utilizing conducting layers separated by stopsUS779178325 juin 20087 sept. 2010Qualcomm Mems Technologies, Inc.Backlight displaysUS780869529 d�c. 20085 oct. 2010Qualcomm Mems Technologies, Inc.Method and apparatus for low range bit depth enhancement for MEMS display architecturesUS78987252 sept. 20101 mars 2011Qualcomm Mems Technologies, Inc.Apparatuses with enhanced low range bit depthUS79163788 mars 200729 mars 2011Qualcomm Mems Technologies, Inc.Method and apparatus for providing a light absorbing mask in an interferometric modulator displayFaire pivoterImage d'origineAccueil Google - Plan du site - T�l�chargements par lot sur l'USPTO - R�gles de confidentialit� - Conditions d'utilisation - � propos de Google�Brevets - Envoyer des commentairesDonn�es fournies par IFI CLAIMS Patent Services©2012 Google