Patent Application
20080036947
Reference will now be made to the drawings to describe embodiments of the present invention in detail.
Referring to
Also referring to
The bottom protective light guide layer 247 includes a top boundary 262 adjacent to the diffusion layer 246, a light incident surface 261 adjoining the top boundary 262, and a bottom surface 263. The bottom surface 263 includes a plurality of pattern dots 260 thereat. In the illustrated embodiment, the pattern dots 160 are in the form of recesses. The light source 25 is disposed adjacent to the light incident surface 261.
The polarizing layer 245 is made of a polyvinyl alcohol (PVA) film, which has ductility and optical polarity. The top protective layer 243 and the bottom protective light guide layer 247 are made of material with characteristics of high light transparence, water resistance, and mechanical strength; for example, triacetyl cellulose (TAC), or the like. In one embodiment, the light source 25 is an LED, which typically has a thickness (i.e. height) of 0.35 mm. The bottom protective light guide layer 247 has a thickness corresponding to that of the light source 25. That is, the thickness of the bottom protective light guide layer 247 is typically 0.35 mm or a little more than 0.35 mm. With the ongoing progress of light source technology, it is believed that the thickness of the light source 25 may be less than 0.35 mm. Whatever the thickness of the light source 25, the bottom protective light guide layer 247 should be correspondingly thick in order to work well with the light source 25.
A typical method of making the bottom polarizer 24 includes the following steps. Iodine ions are permeated into a PVA film. The PVA film is heated and then stretched, so that the iodine ions are rotated and become oriented in a same direction. This ensures that light beams transmitting through the PVA film can be polarized. Then the diffusion layer 246 is attached on one surface of the PVA film. The top protective layer 243 is coated on the other surface of the PVA film, and the bottom protective light guide layer 247 is coated on the diffusion layer 246, in order to protect the PVA film and prevent the PVA film from shrinking. Finally, the adhesive layer 241 is pasted on the top protective layer 243.
Light beams emitted by the light source 25 enter the bottom protective light guide layer 247 though the light incident surface 261. Most of the light beams are reflected at the pattern dots 260 of the bottom protective light guide layer 247, and then transmit through the top boundary 262 to the diffusion layer 246. Some of the light beams transmit out of the bottom protective light guide layer 247 through the bottom surface 263, and then are reflected back into the bottom protective light guide layer 247 by the reflective plate 27. These light beams then also transmit through the top boundary 262 to the diffusion layer 246. All the light beams transmitting to the diffusion layer 246 eventually illuminate the LC panel 23, which can thereby display images.
In alternative embodiments, the pattern dots 260 at the bottom surface 263 can have other suitable shapes, as long as the pattern dots 260 can provide reflection of light beams with an incident angle larger than a critical angle, and provide refraction of light beams with an incident angle less than the critical angle.
In summary, the bottom polarizer 24 of the LCD device 2 includes the bottom protective light guide layer 247. The bottom protective light guide layer 247 is capable of guiding and converting the light beams emitted from the light source 25 to a substantially planar light source, which eventually illuminates the LC panel 23 for displaying of images. With this configuration, the LCD device 2 does not need an LGP. This means an overall thickness of the LCD device 2 is reduced, so that the LCD device 2 is more compact and occupies less space.
Referring to
Also referring to
The top protective light guide layer 321 includes a bottom boundary 362 adjacent to the polarizing layer 322, a light incident surface 361 adjoining the bottom boundary, and a top surface 363 adjoining the light incident surface 361. The top surface 363 defines a plurality of elongate grooves 360 thereat. Each of the grooves 360 is substantially parallel to the light incident surface 361. All the grooves 360 have the same configuration. In particular, each groove 360 has a generally V-shaped configuration as viewed from a lateral side of the LCD device 3. Each groove 360 is bounded by two face portions of the top surface 363. Ridges of the top surface 363 between the grooves 360 are coplanar. The common plane shared by the ridges is perpendicular to the light incident surface 361. For each groove 360, an absolute value of an angle of a first one of the face portions nearer to the light incident surface 361, relative to a plane parallel to the light incident surface 361, is less than an absolute value of an angle of the other second face portion farther from the light incident surface 361, relative to the same plane parallel to the light incident surface 361. Thus, the first face portion and the second face portion have different sizes.
The grooves 360 can provide reflection of light beams that transmit up thereto when such light beams have an incident angle at the top surface 363 which is greater than a critical angle. These reflected light beams transmit back down in the top protective light guide layer 321. The grooves 360 can also provide separation of light beams with an incident angle less than the critical angle. These light beams are separated into two parts. One part of the light beams are reflected and transmit to other grooves 360. The other part of the light beams are refracted and transmit out from the top surface 363 of the polarizer 32.
Thus in operation of the LCD device 3, light beams emitted by the light source 35 transmit into the top protective light guide layer 321 through the light incident surface 361 and substantially reach the grooves 360. Then some of the light beams are reflected back down in the top protective light guide layer 321 and transmit down through the polarizer 32. Other of the light beams are reflected and transmit to other grooves 360 to be re-utilized. Still other of the light beams are refracted and transmit out from the top surface 363 of the polarizer 32. The light beams transmitting down through the polarizer 32 eventually illuminate the LC panel 33, for displaying of images by the LCD device 3.
In summary, the polarizer 32 has the top protective light guide layer 321. The top protective light guide layer 321 is capable of guiding and converting the light beams emitted from the light source 35 to a substantially planar light source, which eventually illuminates the LC panel 33 for displaying of images. With this configuration, the LCD device 3 does not need an LGP. This means an overall thickness of the LCD device 3 is reduced, so the LCD device 3 is more compact and occupies less space.
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 95129590 | Aug 2006 | TW | national |
