Patent Application
20070019132
This application claims priority from Korean Patent Application No. 10-2004-118010 filed on Dec. 31, 2004, the disclosure of which is incorporated herein by reference in its entirety.
1. Technical Field
The present disclosure relates to a microlens substrate array, a method of manufacturing the same, and a three-dimensional (3D) display apparatus including a microlens substrate, and more particularly, to a microlens substrate array that can be fabricated on glass using an alignment key formed on a substrate, a method of manufacturing the same, and a 3D display apparatus including a microlens substrate.
2. Discussion of the Related Art
A three-dimensional display produces different images for a viewer's left and right eyes, thereby providing a sense of depth and a stereoscopic effect. Displaying a stereoscopic image allows the viewer to recognize the 3D arrangement of objects.
An autostereoscopic device is commonly used as a direct-view display in which an observer can see a 3D image without special instruments such as, for example, stereo glasses. The autostereoscopic device in which a lenticular lens sheet or a barrier sheet is mounted on a display panel produces a stereo image by separating the left-eye and right-eye images produced on the display panel so that the left eye sees only the left eye image and the right eye sees only the right eye image.
A conventional 3D display apparatus includes a display panel producing R, G, and B image signals, a microlens substrate with a lenticular sheet that is mounted on the display panel and converts R, G, and B image signals into 3D images, and a switching panel that is mounted on the microlens substrate and converts a 2D image to a 3D image or vice versa.
The conventional 3D display apparatus in which the microlens substrate with the lenticular sheet is disposed on the display panel uses a polarization-conversion technique. 3D displays are classified into portrait-type (PT) and landscape type (LT) displays depending on the arrangement of a color filter and lenticular lenses on a lenticular lens sheet.
When long sides of the RGB subpixels in a single pixel extend along a longitudinal direction of a liquid crystal panel, a PT display is configured such that lenticular lenses of a lenticular sheet are arranged in parallel along the longitudinal direction of the subpixels, i.e., in the vertical direction of a screen. An LT display is configured such that lenticular lenses are aligned on a lenticular lens substrate in parallel along the transverse direction of the subpixels, i.e., in the horizontal direction of the screen.
The PT display commonly uses a structure in which two subpixels correspond to one lenticular lens so that three primary colors generated by six adjacent subpixels, i.e., left-eye and right-eye data signals, reach the left and right eyes, respectively.
A conventional method of manufacturing the microlens substrate having the above-mentioned configuration in the conventional 3D display includes applying a resin on a lower substrate, placing the resin into a mold for a lenticular lens array to form the shape of a lenticular lens, thereby completing a microlens sheet cell by cell, cutting the microlens sheet into individual cells, and mounting an upper substrate on each individual cell.
High-volume production of the microlens substrate is difficult with the conventional method, which fabricates the microlens sheet cell by cell due to a mold size limitation.
Embodiments of the present invention provide a microlens substrate array with excellent reproducibility that can be fabricated on glass for high-volume production, a three-dimensional (3D) display apparatus including a microlens substrate, and a method of manufacturing the microlens substrate.
According to an embodiment of the present invention, a microlens substrate array includes an upper transparent substrate and a lower transparent substrate facing the upper transparent substrate, and a microlens sheet of a photosensitive resin formed between the upper and lower substrates, the microlens sheet including a plurality of lenticular lens arrays corresponding to a plurality of cells arranged on a surface of the microlens sheet and planar surfaces formed along edges of each of the plurality of cells.
According to an embodiment of the present invention, a microlens substrate array includes an upper transparent substrate and a lower transparent substrate facing the upper transparent substrate, a microlens sheet made of a photosensitive resin, including a plurality of lenticular lens arrays that are formed on the lower substrate between the upper and lower substrates and correspond to a plurality of cells and exposing the lower substrate along edges of each of the plurality of cells, and a seal line directly contacting the exposed lower substrate and the upper substrate and combining the upper substrate with the lower substrate.
According to an embodiment of the present invention, a three-dimensional display apparatus includes a display panel producing an image, and a microlens substrate including an upper transparent substrate that is disposed on of the display panel and transmits the image, a lower transparent substrate facing the upper transparent substrate, and a microlens sheet of a photosensitive resin that is formed between the upper and lower substrates and includes a lenticular lens array and planar surfaces formed along edges of the lenticular lens array.
According to an embodiment of the present invention, a three-dimensional display apparatus includes a display panel producing an image, and a microlens substrate including an upper transparent substrate that is disposed on the display panel and transmits the image, a lower transparent substrate facing the upper transparent substrate, a microlens sheet made of a photosensitive resin, which includes a lenticular lens array, that is formed on the lower substrate between the upper and lower substrates, and exposes the lower substrate along edges of the lenticular lens array, and a seal line directly contacting the exposed lower substrate and the upper substrate and combining the upper substrate with the lower substrate.
According to an embodiment of the present invention, a method of manufacturing a microlens substrate includes forming a microlens sheet of a photosensitive resin including a lenticular lens array on a lower substrate, exposing the microlens sheet to light through a mask dividing the lenticular lens array into a plurality of portions respectively corresponding to a plurality of cells and defining a boundary between each of the plurality of cells, planarizing a portion of the microlens sheet corresponding to the boundary, and forming a seal line on the planarized boundary to combine the lower substrate with a corresponding upper substrate.
According to an embodiment of the present invention, a method of manufacturing a microlens substrate includes forming a microlens sheet of a photosensitive resin including a lenticular lens array on a lower substrate, exposing the microlens sheet to light through a mask dividing the lenticular lens array into a plurality of portions respectively corresponding to a plurality of cells and defining a boundary between each of the plurality of cells, removing a portion of the microlens sheet corresponding to the boundary to expose the lower substrate, and forming a seal line on the boundary formed on the exposed lower substrate to combine the lower substrate with a corresponding upper substrate.
Preferred embodiments of the present disclosure can be understood in more detail from the following description taken in conjunction with the accompanying drawings in which:
Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Referring to
The display panel 25 may be, for example, a liquid crystal display (LCD), a plasma display panel (PDP), a field emission device (FED), or an organic electro-luminescence display (OELD), which can produce red, green, and blue colors. The 3D display apparatus 100 is hereinafter described as using an LCD.
The display panel 25 controls transmittance of light passing through a liquid crystal layer 15 depending on the magnitude of an applied voltage, thereby displaying images such as, for example, a variety of characters, numbers, and icons. The display panel 25 produces a common RGB image when displaying a common 2D image. When displaying a 3D image, adjacent subpixels in the display panel 25 generate images containing parallax.
The display panel 25 includes a thin film transistor (TFT) substrate 10, a color filter substrate 20 facing the TFT substrate 10, and a liquid crystal layer 15 positioned between the TFT substrate 10 and the color filter substrate 20.
While not shown in
The switching device is formed at an intersection between a gate line and a data line and includes an output terminal connected to terminals of the storage capacitor and the liquid crystal capacitor. The other terminal of the storage capacitor may be connected to a reference electrode (separate wire type) or to a previous gate line (previous gate type).
The color filter substrate 20 is disposed on the TFT substrate 10 and includes red, green, and blue color filters that correspond to subpixels and display corresponding colors. The reference electrode is formed on the color filter using a transparent conducting material such as indium tin oxide (ITO) or indium zinc oxide (IZO).
The liquid crystal layer 15 having dielectric anisotropy is filled between the TFT substrate 10 and the color filter substrate 20. The liquid crystal layer 15 with a thickness of about 5 μm has a twisted nematic (TN) alignment structure. The alignment direction of liquid crystals in the liquid crystal layer 15 is altered by an externally applied voltage to control the transmittance of light passing through the liquid crystal layer 15.
When the display panel 25 is an LCD, the display panel 25 may further include a backlight unit (not shown) with a light source located behind the LCD. Light emitted from the backlight unit to the display panel 25 is transmitted into the color filter substrate 20 through the liquid crystal layer 15. The amount of light transmitted is adjusted according to the alignment direction of liquid crystals in the liquid crystal layer 15.
The light transmitted through the display panel 25 passes through the microlens substrate 30 disposed on the display panel 25. The microlens substrate 30 includes an upper transparent substrate 37, a lower transparent substrate 31, and a microlens sheet 32 interposed between the upper and lower transparent substrates 37 and 31. The microlens substrate 30 directs three primary colors generated by subpixels, corresponding to left-eye and right-eye data signals, to an appropriate eye.
Referring to
A pitch of the lenticular lens array 33 is set to have a constant relationship with a horizontal pitch of subpixels along the transverse direction of the display panel 25. While the 3D display apparatus 100 is configured such that one lenticular lens corresponds to two subpixels, the lenticular lens may correspond to three or more subpixels depending on the number of perspectives.
While the 3D display apparatus 100 is a landscape type display, a portrait type display apparatus 100′ of
Seal lines 35 are formed on the planar surface 34 of the microlens sheet 32 and combine the upper substrate 37 with the lower substrate 31. The seal lines 35 make a gap between the upper and lower substrates 37 and 31 to inject liquid crystals and prevent the injected liquid crystals from escaping out of the gap. The seal lines 35 are formed by, for example, patterning a thermosetting epoxy resin in a desired shape.
The height of the seal lines 35 is about several micrometers, and a peak-to-valley height of the lenticular lens array 33 is about several tens of micrometers. Since the height of the seal lines 35 is less than the peak-to-valley height, adequate bonding between the upper and lower substrates 37 and 31 cannot be achieved if the lenticular lens array 33 is formed on the planar surface where the seal lines 35 are formed. Thus, the microlens sheet 32 is designed such that the lenticular lens array 33 is disposed at the center and the seal lines 35 are placed on the planar surface 34 formed along the edges of the lenticular lens array 33, thereby achieving reliable bonding between the upper and lower substrates 37 and 31.
A liquid crystal layer 36 is formed in the gap between the upper and lower substrates 37 and 31.
The switching panel 40 is disposed on the display panel 25 and spaced apart from the display panel 25, and enables the display apparatus 100 to selectively display a 2D or 3D image in response to a switching signal.
For example, the switching panel 40 transmits all of the light from the TFT substrate 10 when displaying a 2D image and includes a structure corresponding to pixel information on the TFT substrate 10. For example, when the 3D image is displayed, the switching panel 40 comprises an effective image display region that can transmit light and a selective blocking region surrounding the effective image display region. The selective blocking region controls whether to block light in response to the switching signal.
The switching panel 40 may comprise a liquid crystal panel that can turn light on or off according to the switching signal. For example, the switching panel 40 may be a super twisted nematic (STN) liquid crystal panel or a twisted nematic (TN) liquid crystal panel.
The upper substrate 37 combines with the lower substrate 31 to cover a top surface of the lower substrate 31, with the microlens sheet 32 interposed therebetween.
The microlens sheet 32 comprises a photosensitive resin and includes the plurality of lenticular lens arrays 33 corresponding to the plurality of cells 50 arranged on the surface of the microlens sheet 32. Planar surfaces 34 are formed along edges of each of the plurality of cells 50. A seal line (not shown) is disposed on the planar surface 34 to achieve adequate bonding between the upper and lower substrates 37 and 31 without being affected by irregularities. of the lenticular lens array 33.
In this way, the plurality of cells 50 is defined on the microlens sheet 32 in the microlens substrate array 250. Thus, the microlens substrate array 250 can be cut into individual cells 50 and divided into a plurality of microlens substrates 30.
A method of manufacturing a microlens substrate according to an embodiment of the present invention will now be described with reference to
Referring to
The mold film 300 may be, for example, a roll-type film. The roll-type mold film 300 is easy to carry and can be arranged on bulk glass at uniform intervals. Before positioning the mold film 300 and the lower substrate 31, an alignment key (not shown) may be formed on one surface of the lower substrate 31 facing the microlens sheet 32. The alignment key is used to position upper and lower substrates when a plurality of microlens substrates are formed simultaneously on bulk glass.
Referring to
Subsequently, as shown in
Referring to
Then, as shown in
Referring to
Subsequently, as shown in
As described above, when the plurality of microlens substrates 30 are fabricated simultaneously using bulk glass, the alignment keys are formed on the upper and lower substrates 37 and 31 for accurate positioning. The alignment keys may be used to achieve bonding between the upper and lower substrates 37 and 31 or to position the lower substrate 31 during the exposure shown in
A 3D display apparatus according to an embodiment of the present invention and a method of manufacturing a microlens substrate array according to an embodiment of the present invention will now be described with reference to
Referring to
While the microlens sheet 532 is described to have the concave lenticular lens array 33, it may use a convex lenticular lens array to achieve the same effect.
Seal lines 35 are formed on the boundaries 534 located at the edges of the microlens sheet 532 and function to combine the upper substrate 37 with the lower substrate 31. The height of the seal lines 35 is greater than the thickness of the microlens sheet 532. For example, the seal lines 35 have a height of about several ten micrometers to about several hundred micrometers.
Referring to
The upper substrate 37 combines with the lower substrate 31 to cover a top surface of the lower substrate 31, with the portions of the microlens sheet 532 interposed therebetween.
The microlens sheet 532 comprises a photosensitive resin and includes the plurality of lenticular lens arrays 33 corresponding to the plurality of cells 50 arranged on the surface of the lower transparent substrate 31. The lower transparent substrate 31 is exposed along a boundary 534 of each cell 50. A seal line (not shown) is formed on each boundary 534 to achieve adequate bonding between the upper and lower substrates 37 and 31.
The plurality of cells 50 are defined on the microlens sheets 532 in the microlens substrate array 650. Thus, the microlens substrate array 650 can be cut into individual cells 50 and divided into a plurality of microlens substrates 530.
The method of manufacturing a microlens substrate 530 according to an embodiment of the present invention will now be described with reference to
Then, the microlens sheet 532 thermally pressed onto the lower substrate 31 is baked at about 200° C. to about 250° C. The lenticular lens array 33 is formed at the portions A of the microlens sheet 532 irradiated with the light 340 during the exposure. The remaining portions C of the microlens sheet 532 not irradiated with the light 340 are removed to expose the lower substrate 31.
Referring to
Subsequently, as shown in
As described earlier, when the plurality of microlens substrates 530 are fabricated simultaneously using bulk glass, the alignment keys are formed on the upper and lower substrates 37 and 31 for precise positioning. The alignment keys may be used to achieve bonding between the upper and lower substrates 37 and 31 or to position the lower substrate 31 during the exposure shown in
A microlens substrate array comprising a plurality of cells precisely aligned on bulk glass can be fabricated using the alignment keys.
As described above, embodiments of the present invention provide a microlens substrate array that can be fabricated on bulk glass to allow high-volume production, and with an alignment key formed on a substrate to provide excellent reproducibility and thus increase manufacturing yield, a method of manufacturing the same, and a 3D display apparatus including a microlens substrate.
Although preferred embodiments have been described with reference to the accompanying drawings, it is to be understood that the present invention is not limited to these precise embodiments but various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the present invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2004-0118010 | Dec 2004 | KR | national |
