Source: http://www.google.com/patents/US20050007513?ie=ISO-8859-1&dq=7,117,286
Timestamp: 2016-02-13 07:55:38
Document Index: 649258810

Matched Legal Cases: ['art 65', 'art 65', 'art 65', 'art 65', 'art 65', 'art 65', 'art 65']

Patent US20050007513 - Optical sheet and LCD apparatus using the same - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsThe present invention relates to an optical sheet and an LCD apparatus using the same. An LCD apparatus according to the present invention comprises an LCD panel to display a picture thereon; a lamp unit emitting light; a light guide plate to guide the light from the lamp unit toward the LCD panel evenly;...http://www.google.com/patents/US20050007513?utm_source=gb-gplus-sharePatent US20050007513 - Optical sheet and LCD apparatus using the sameAdvanced Patent SearchPublication numberUS20050007513 A1Publication typeApplicationApplication numberUS 10/792,414Publication dateJan 13, 2005Filing dateMar 3, 2004Priority dateMar 5, 2003Also published asCN1303462C, CN1530713A, US7349039Publication number10792414, 792414, US 2005/0007513 A1, US 2005/007513 A1, US 20050007513 A1, US 20050007513A1, US 2005007513 A1, US 2005007513A1, US-A1-20050007513, US-A1-2005007513, US2005/0007513A1, US2005/007513A1, US20050007513 A1, US20050007513A1, US2005007513 A1, US2005007513A1InventorsJeong-hwan Lee, Byung-Woong Han, Jong-Dae Park, Dong-Hoon Kim, Ming-gyu KimOriginal AssigneeLee Jeong-Hwan, Byung-Woong Han, Jong-Dae Park, Dong-Hoon Kim, Kim Ming-GyuExport CitationBiBTeX, EndNote, RefManPatent Citations (7), Referenced by (24), Classifications (13), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetOptical sheet and LCD apparatus using the same
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0046] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. [0047] As shown in FIG. 2, an optical sheet 60 according to a first embodiment of the present invention comprises a reflective polarizing layer 61 selectively transmitting and reflecting light, and a condensing layer 62 attached to one surface of the reflective polarizing layer 61 and condensing the light. [0048] The reflective polarizing layer 61 selectively transmits and reflects the light. The reflective polarizing layer 61 is formed by layering films which have the same refractive index of an X-axis and are different in a refractive index of a Y-axis; therefore, X-axis vibrating components of the light can be transmitted through the X-axis, but the other components including Y-axis vibrating components are reflected. For example, P-wave components of the light from the lamp unit 130 are transmitted through the reflective polarizing layer 61, and S-wave components thereof are reflected from the reflective polarizing layer 61. [0049] The condensing layer 62 is attached to the one surface of the reflective polarizing layer 61 and condenses the light. The condensing layer 62 is achieved by coating the one surface of the reflective polarizing layer 61 with acrylic resin and then forming a plurality of prism teeth 63 on the acrylic resin, wherein the prism teeth 63 are parallel arranged at intervals of a predetermined pitch. The prism teeth 63 formed on the condensing layer 62 are employed for condensing the incident light toward the reflective polarizing layer 61. In this embodiment, the prism teeth 63 have a triangular cross section. However, the prism teeth may have a polygonal cross section, or an edge of the prism teeth 63 may be rounded off. Further, it is preferable that the pitch between the prism teeth is 20 μm˜100 μm and an inclination angle of the prism tooth is 60�˜70�. [0050] FIG. 3 is a sectional view of an optical sheet according to a second embodiment of the present invention. As shown therein, an optical sheet 60 a according to the second embodiment comprises a reflective polarizing layer 61 selectively transmitting and reflecting light, a condensing layer 62 attached to one surface of the reflective polarizing layer 61 and condensing the light, and a diffusing part 65 provided on the other surface of the reflective polarizing layer 61 and diffusing the light. Here, the reflective polarizing layer 61 and the condensing layer 62 according to the second embodiment are the same as those according to the first embodiment, and repetitive descriptions thereof will be avoided. [0051] The diffusing part 65 is achieved by a plurality of beads (refer to FIG. 3) capable of diffusing the light. However, the diffusing part 65 may be achieved by a prominence and depression pattern. Here, it is preferable that the diffusing part 65 allows the light passed through the reflective polarizing layer 61 to have a haze value of at least 30%. Thus, the optical sheet 60 a can prevent moire and rainbow patterns due to the condensing layer 62 from occurring in the LCD apparatus. [0052] FIG. 4 is a sectional view of an optical sheet according to a third embodiment of the present invention. As shown therein, an optical sheet 60 b according to the third embodiment comprises a reflective polarizing layer 61 selectively transmitting and reflecting light, a condensing layer 62 attached to one surface of the reflective polarizing layer 61 and condensing the light, and a first reinforcing layer 64 a attached to the other surface of the reflective polarizing layer 61 and preventing the optical sheet 60 b from shrinking. Here, the reflective polarizing layer 61 and the condensing layer 62 according to the third embodiment are the same as those according to the first embodiment, and repetitive descriptions thereof will be avoided. [0053] The first reinforcing layer 64 a is achieved by coating the other surface of the reflective polarizing layer 61 with polycarbonate resin. The first reinforcing layer 64 a is employed in preventing the optical sheet 60 b from a shrink due to the condensing layer 62 attached to only one surface of the reflective polarizing layer 61. [0054] FIG. 5 is a sectional view of an optical sheet according to a fourth embodiment of the present invention. As shown therein, an optical sheet 60 c according to the fourth embodiment comprises a reflective polarizing layer 61 selectively transmitting and reflecting light, a first reinforcing layer 64 a attached to one surface of the reflective polarizing layer 61 and preventing the optical sheet 60 c from shrinking, a second reinforcing layer 64 b attached to the other surface of the reflective polarizing layer 61 and preventing the optical sheet 60 c from shrinking, and a condensing layer 62 attached to the second reinforcing layer 64 b and condensing the light. Here, the reflective polarizing layer 61, the condensing layer 62, and the first reinforcing layer 64 a according to the fourth embodiment are the same as those according to the third embodiment, and repetitive descriptions thereof will be avoided. [0055] The second reinforcing layer 64 b is provided between the reflective polarizing layer 61 and the condensing layer 62, so that the whole thickness of the optical sheet 60 c is increased, thereby preventing the optical sheet 60 b from shrinking. Like the first reinforcing layer 64 a, the second reinforcing layer 64 b is made of the polycarbonate resin. [0056] On the other hand, a diffusing part 65 can be provided on an outer surface of the first reinforcing layer 64 a of each optical sheet 60 b and 60 c according to the third and fourth embodiments in order to diffuse the light. That is illustrated in FIG. 6 as an optical sheet 60 d according to a fifth embodiment of the present invention. In the optical sheet 60 d of FIG. 6, a plurality of beads is exemplarily formed as the diffusing part 65 on the outer surface of the first reinforcing layer 64 a. Here, it is preferable that the diffusing part of the optical sheet allows the light passed through the first reinforcing layer 64 a to have a haze value of at least 30%. Thus, the optical sheet 60 d can prevent moire and rainbow patterns due to the condensing layer 62 from occurring in the LCD apparatus. [0057] FIG. 7 is a sectional view of an optical sheet according to a sixth embodiment of the present invention. As shown therein, an optical sheet 60 e according to the sixth embodiment comprises a reflective polarizing layer 61 selectively transmitting and reflecting light, a reinforcing layer 64 c attached to one surface of the reflective polarizing layer 61 and preventing the optical sheet 60 e from shrinking, and a condensing layer 62 attached to the reinforcing layer 64 c and condensing the light. Here, the reflective polarizing layer 61 and the condensing layer 62 according to the sixth embodiment are the same as those according to the first embodiment, and repetitive descriptions thereof will be avoided. [0058] The reinforcing layer 64 c is provided between the reflective polarizing layer 61 and the condensing layer 62, so that the whole thickness of the optical sheet 60 e is increased, thereby preventing the optical sheet 60 e from shrinking. [0059] Further, in the optical sheet 60 e according to the sixth embodiment, a diffusing part 65 is formed on the outer surface of the reflective polarizing layer 61. Therefore, the optical sheet 60 e can prevent moire and rainbow patterns due to the condensing layer 62 from occurring in the LCD apparatus. [0060] Hereinbelow, an LCD apparatus according to a first embodiment of the present invention using the above-described optical sheets will be described with reference to FIG. 8, wherein the optical sheet 60 according to the first embodiment is exemplarily used. [0061] An LCD apparatus according to the first embodiment comprises an LCD panel 10 to display images thereon, a lamp unit 30 emitting light, a light guide plate 20 to guide the light from the lamp unit 30 toward the LCD panel 10 evenly, and a reflector 50 provided behind the light guide plate 20 and reflecting the light arriving at the reflector 60 into the light guide plate 20. Further, the LCD apparatus according to the first embodiment comprises the optical sheet 60; the optical sheet 60 is provided between the LCD panel 10 and the light guide plate 20 and includes the condensing layer 62 condensing the light from the light guide plate 20 on the LCD panel 10, and the reflective polarizing layer 61 attached to the surface of the condensing layer 62 facing the LCD panel 10 and selectively transmitting and reflecting the light condensed by the condensing layer 62. [0062] The LCD panel 10 includes a TFT (thin film transistor) array substrate 12 formed with switching elements and pixel electrodes, a color filter substrate 11, and a liquid crystal (not shown) filled between the TFT array substrate 12 and the color filter substrate 11. An electric signal including image data is transmitted to transistors of the TFT array substrate 12 via a source PCB (printed circuit board) and a gate PCB; the liquid crystal displays the images with the light transmitted through the light guide plate 20 while the electric current passes through the liquid crystal. Further, on the outer surfaces of the color filter substrate 11 and the TFT array substrate 12 are respectively provided polarizing plates 13 to selectively reflect and absorb the light, thereby enhancing the brightness of the LCD apparatus. [0063] The lamp unit 30 is provided in a lateral side of the light guide plate 20 and emits the light toward the light guide plate 20. Here, the lamp unit 30 includes a CCFL (cold cathode fluorescent lamp), an EL (electro luminescence), an LED (light emitting diode), etc. [0064] Further, a lamp reflector 40 is provided in the lateral side of the light guide plate 20, covering the lamp Unit 30. The lamp reflector 40 reflects the light arriving at the lamp reflector 40 into the light guide plate 20, thereby decreasing light loss. [0065] The light guide plate 20 is made of a transparent plastic material such as an acryl, etc., and guides the light from the lamp unit 130 toward the LCD panel 10 uniformly. On the rear surface of the light guide plate 20 is formed a fine pattern such as a dotted pattern, etc. to reflect the light emitted from the lamp unit 30 toward the LCD panel 10. Further, on the rear surface of the light guide plate 20 is formed a plurality of prism teeth (not shown) parallel arranged at intervals of a predetermined pitch. The prism teeth are employed in condensing the light toward the LCD panel 10. [0066] The optical sheet 60 of the first embodiment is provided between the LCD panel 10 and the light guide plate 20. In the optical sheet 60, the reflective polarizing layer 61 faces the LCD panel 10, and the condensing layer 62 faces the light guide plate 20. Further, the prism teeth 63 of the condensing layer 62 and the prism teeth of the light guide plate 20 cross each other. Thus, the light transmitted from the light guide plate 20 toward the LCD panel 10 is condensed by the condensing layer 20, and then the condensed light is partially reflected and partially transmitted by the reflective polarizing layer 61. [0067] The reflective polarizing layer 61 is formed by layering films which have the same refractive index of an X-axis and are different in a refractive index of a Y-axis; therefore, the light can be transmitted through the X-axis of which the refractive index is the same to every film, but cannot be transmitted through the Y-axis of which the refractive index is different according to every film. That is, X-axis vibrating components of the light condensed by the condensing layer 62 pass through the reflective polarizing layer 61, but the other components including Y-axis vibrating components are reflected from the reflective polarizing layer 61. For example, P-wave components, vibrating in parallel with the X-axis, of the light from the light guide plate 20 are transmitted through the reflective polarizing layer 61, and S-wave components, vibrating in parallel with the Y-axis, thereof are reflected from the reflective polarizing film 61. Here, the S-wave components of the light reflected from the reflective polarizing layer 61 are reflected again from the light guide plate 20 or the reflector 50 toward the LCD panel 10. On this way, the reflected S-wave components are changed into the P-wave components and then pass through the reflective polarizing layer 61, thereby minimizing the light loss. Herein, the X-axis, as a transmitting axis, of the reflective polarizing layer 61 is inclined by about 45� degrees relative to a lengthwise direction of the optical sheet 60. [0068] On the other hand, FIG. 9 shows an LCD apparatus according to a second embodiment of the present invention using the above-described optical sheets. Hereinbelow, the LCD apparatus will be described with reference to FIG. 9, wherein the optical sheet 60 according to the first embodiment is exemplarily used, and repetitive descriptions thereof will be avoided as necessary. [0069] The LCD apparatus according to the second embodiment comprises an LCD panel 10 to display images thereon, a lamp unit 30 emitting light, a light guide plate 20 to guide the light from the lamp unit 30 toward the LCD panel 10 evenly, and a reflector 60 provided behind the light guide plate 20 and reflecting the light arriving at the reflector 60 into the light guide plate 20. Further, the LCD apparatus according to the second embodiment comprises the optical sheet 60; the optical sheet 60 is attached to the LCD panel 10 and includes the condensing layer 62 condensing the light from the light guide plate 20, and the reflective polarizing layer 61 selectively transmitting and reflecting the light condensed by the condensing layer 62. [0070] The LCD panel 10 includes a TFT array substrate 12, a color filter substrate 11, and a liquid crystal (now shown) filled between the TFT array substrate 12 and the color filter substrate 11. Further, on the outer surfaces of the color filter substrate 11 and the TFT array substrate 12 are respectively provided polarizing plates 13 to selectively reflect and absorb the light. In this embodiment, the optical sheet 60 is attached to the surface of the polarizing plate 13 provided on the outer surface of the TFT array substrate 12, that is, the optical sheet 60 and the LCD panel 10 are formed as a single body. Further, the transmitting axis of the polarizing plate 13 provided on the surface of the TFT array substrate is preferably aligned with the transmitting axis of the optical sheet 60 in order to decrease light loss and enhance the brightness. For example, if the optical sheet 60 passes the P-wave components therethrough and reflects the S-wave components therefrom, the polarizing plate 13 provided on the surface of the TFT array substrate passes the P-wave components therethrough and absorbs the S-wave components. [0071] In the above-described embodiment, the prism teeth 64 of the condensing layer 62 are formed along the lengthwise direction of the optical sheet 60. However, the prism teeth of the condensing layer may be formed along the transmitting axis direction of the reflective polarizing layer. For example, as shown in FIG. 10, in the case where the transmitting axis “A” of the reflective polarizing layer 61 is inclined by about 45� degrees relative to a lengthwise direction of the optical sheet 60 f, the prism teeth 64 of the condensing layer 62 are inclined by about 45� degrees relative to a lengthwise direction of the optical sheet 60 f. In this LCD apparatus, the transmitting axis of the polarizing plate provided on the rear surface of the TFT array substrate of the LCD panel is aligned with the transmitting axis of the reflective polarizing layer 61, and the prism teeth of the light guide plate may be perpendicular to the prism teeth 63 of the condensing layer 62. Thus, moire and rainbow patterns occurring in the LCD apparatus are decreased. [0072] In the foregoing embodiment, it was described that the optical sheet 60 according to the first embodiment is used in the LCD apparatus according to the present invention. However, the optical sheet according to the second through sixth embodiments may be used in the LCD apparatus according to the present invention. [0073] Preferably, the reinforcing layers of the optical sheets according to the foregoing embodiments are made of a material such as polycarbonate resin, which does not polarize the light, so that the brightness is enhanced and the light loss is decreased. [0074] As described above, there is provided an optical sheet comprising a reflective polarizing layer selectively reflecting and transmitting light, and a condensing layer attached to one surface of the reflective polarizing layer and condensing the light, so that brightness are enhanced, and the optical sheet is prevented from shrinking. Further, there is no need of a base layer made of the PET and used in the conventional prism sheet, so that production cost is decreased. [0075] As described above, the present invention provides an optical sheet and an LCD apparatus using the same, in which a bright-line is decreased, brightness are enhanced, and the optical sheet is prevented from shrinking. [0076] Although a few embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents. 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Philips Lcd Co., Ltd.Prismenlage und Hinterleuchtungseinheit unter Verwendung derselbenEP1942681A1 *Sep 26, 2007Jul 9, 2008Samsung Electronics Co., Ltd.Highly efficient 2D/3D switchable autostereoscopic display deviceEP2075623A2 *Dec 11, 2008Jul 1, 2009Samsung Electronics Co., Ltd.Optical sheet and display device having the sameEP2075623A3 *Dec 11, 2008Apr 28, 2010Samsung Electronics Co., Ltd.Optical sheet and display device having the sameEP2075624A2 *Dec 18, 2008Jul 1, 2009Samsung Electronics Co., Ltd.Optical sheet and display device having the sameEP2075624A3 *Dec 18, 2008Apr 28, 2010Samsung Electronics Co., Ltd.Optical sheet and display device having the same* Cited by examinerClassifications U.S. Classification349/57International ClassificationG02B5/30, F21Y103/00, G02B5/04, G02F1/13357, G02F1/1335, F21V8/00Cooperative ClassificationG02F1/133615, G02B6/0056, G02B6/0053European ClassificationG02F1/1336E, G02B6/00L6O8P, G02B6/00L6O14Legal EventsDateCodeEventDescriptionJan 17, 2008ASAssignmentOwner name: SAMSUNG ELECTRONICS CO., LTD, KOREA, REPUBLIC OFFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LEE, JEONG-HWAN;HAN, BYUNG-WOONG;PARK, JONG-DAE;AND OTHERS;REEL/FRAME:020376/0051Effective date: 20080111Aug 18, 2011FPAYFee paymentYear of fee payment: 4Sep 14, 2012ASAssignmentOwner name: SAMSUNG DISPLAY CO., LTD., KOREA, REPUBLIC OFFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SAMSUNG ELECTRONICS CO., LTD.;REEL/FRAME:028984/0774Effective date: 20120904Sep 16, 2015FPAYFee paymentYear of fee payment: 8RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services