TWI457885B - Display apparatus - Google Patents

Description

Display device

The present invention relates to a display device, and more particularly to a display device that can switch between different display modes, such as stereoscopic and planar display modes.

The current stereoscopic display technology can be roughly divided into an auto-stereoscopic view that can be directly viewed by a viewer, and a stereoscopic view that needs to be worn with special design glasses. Either display technology uses the characteristics of light (such as polarization direction, direction of travel, etc.) to control the images received by the viewer's left and right eyes. According to the visual characteristics of the human eye, when the images viewed by the left and right eyes respectively have different parallaxes, the human brain observes the interpretation of the two images as a stereoscopic image.

In order to provide the display device with both the flat display function and the stereoscopic display function, a switchable panel is generally installed in front of the display panel for the display screen to control the characteristics of the displayed light by the switchable panel. Basically, the switchable panel includes two substrates, a liquid crystal layer between the two substrates, and at least one electrode layer that controls the liquid crystal layer, which utilizes the optical characteristics of the liquid crystal layer to control the characteristics of the displayed light. A polymer can be used as the material of the substrate in consideration of the slimness and low cost of the exterior. However, substrates made of polymeric materials are generally flexible, and after the switchable panels are assembled, such substrates are likely to bend due to an imbalance between external pressure and internal pressure. The curved substrate in turn causes the thickness of the liquid crystal layer to change, and thus the effect that the switchable panel can provide is greatly discounted.

The present invention provides a display device having a switchable panel having light and thin characteristics and having good quality.

The invention provides a display device comprising a display panel and a switchable panel. The display panel has a display surface, and the switchable panel is located in front of the display surface. The switchable panel includes a first flexible substrate, a second flexible substrate, a first electrode layer, a second electrode layer, a plurality of spacers, and an optical medium. The first flexible substrate is opposed to the second flexible substrate. The first electrode layer is disposed on the first flexible substrate and located between the first flexible substrate and the second flexible substrate. The second electrode layer is disposed on the second flexible substrate and located between the first flexible substrate and the second flexible substrate. The spacer is disposed between the first flexible substrate and the second flexible substrate, wherein the adjacent two spacers are separated by a separation distance and the separation distance is 20 micrometers to 200 micrometers. The optical medium is disposed between the first electrode layer and the second electrode layer, and the optical medium is filled between the spacers.

In one embodiment of the invention, the separation distance is no greater than 150 microns.

In an embodiment of the invention, the switchable panel includes an active area, and the ratio of the total area of the cross-section of the spacer to the active area of the first flexible substrate and the second flexible substrate is 0.05% to 5%.

In an embodiment of the invention, the first flexible substrate and the second flexible substrate have a Young's modulus of 2 GPa to 3 GPa.

In an embodiment of the invention, the first flexible substrate and the second flexible substrate have a thickness of 20 micrometers to 200 micrometers.

In an embodiment of the invention, each of the spacers has a height of from 3 micrometers to 5 micrometers.

In an embodiment of the invention, each of the spacers is substantially a columnar spacer. In addition, each of the spacers is substantially parallel to a cross-sectional area of the first flexible substrate or the second flexible substrate. Alternatively, a cross-sectional area of each of the spacers parallel to the first flexible substrate or the second flexible substrate is substantially changed from the first flexible substrate to the second flexible substrate. In one embodiment, the cross-sectional width of each spacer parallel to the first flexible substrate or the second flexible substrate is, for example, 5 micrometers to 25 micrometers.

In one embodiment of the present invention, one end of each of the spacers is substantially fixed to one of the first flexible substrate and the second flexible substrate, and the other end substantially abuts against the first flexible substrate. The other one with the second flexible substrate.

In an embodiment of the invention, the material of the spacer includes a photoresist material.

In an embodiment of the invention, the distance between the first flexible substrate and the second flexible substrate is substantially uniform.

In an embodiment of the invention, the spacer is configured to maintain a substantially uniform gap thickness between the first flexible substrate and the second flexible substrate.

In an embodiment of the invention, the material of the first flexible substrate and the second flexible substrate comprises polycarbonate (Polycarbonate, PC), polyethylene terephthalate (PET), and poly Polyimide (PI), Polyethersulfone (PES), Cyclic Olefin Copolymer (COC), Cyclo Olefin Polymer (COP), or a combination thereof.

Based on the above, the display device of the present invention is provided with a switchable panel to enable both display mode and stereo display mode. The switchable panel uses a flexible substrate and a plurality of spacers are disposed between the two flexible substrates to support the two flexible substrates. The arrangement position of these spacers can be effectively designed to avoid the phenomenon that the flexible substrate is bent due to the force imbalance. Therefore, the optical medium in the switchable panel has a substantially uniform thickness to maintain good quality, and the display device of the present invention utilizes such a good switchable panel to achieve a desired display effect.

The above described features and advantages of the present invention will be more apparent from the following description.

FIG. 1 is a schematic side view of a display device according to an embodiment of the invention. Referring to FIG. 1 , the display device 10 includes a display panel 100 and a switchable panel 200 . The display panel 100 has a display surface 100A, and the switchable panel 200 is located in front of the display surface 100A. Specifically, the switchable panel 200 can be adhered to the front of the display surface 100A of the display panel 100 by an optical adhesive 300. However, the switchable panel 200 and the display panel 100 can also be assembled in other manners. This is limited to this.

The display panel 100 includes, for example, a first substrate 110, a second substrate 120, and a display medium 130 disposed between the first casing 110 and the second substrate 120. The display panel 100 herein refers to a member for displaying a screen, and the display of the screen can be performed separately. For example, the display panel 100 may be a liquid crystal display panel, an organic electroluminescent display panel, a plasma display panel, or other panels that are known to display a picture.

In addition, the switchable panel 200 is a switchable panel having different optical characteristics to control the display light of the display panel 100, thereby achieving the effect of a flat display or a stereoscopic display. In detail, the switchable display panel 200 can be selectively provided with two modes, one of which is a non-stereo mode and the other of which is a stereo mode. When the switchable panel 200 is in the non-stereo mode, the switchable panel 200 can directly pass the display light of the display panel 100 without a change in characteristics. At this time, the image seen by the user is the screen displayed on the display panel 100. When the switchable panel 200 is in the stereo mode, the switchable panel 200 can change the display light of the display panel 100. At this time, the image seen by the user will be different from the screen displayed by the display panel 100.

For example, when the switchable panel 200 is in the stereo mode, the switchable panel 200 can change the emission direction of the display light of the display panel 100 or only allow the display light of a specific polarization state to pass. In this way, the left eye and the right eye of the user can receive different screen information by wearing polarized glasses or directly watching, and the user can feel the stereo image when the screen information received by the two eyes has parallax. . Therefore, in the embodiment, the switchable panel 200 provides the function of controlling the display panel 100. Light is shown to allow the display device 10 to selectively perform a stereoscopic display mode or a flat display mode.

Since the display device 10 is composed of at least two panels (the display panel 100 and the switchable panel 200), such a design necessarily increases the volume and weight of the display device 10. Therefore, the switchable panel 200 of the present embodiment is selected to be made of a member having a thin and light characteristic. 2 is a cross-sectional view of a switchable panel according to an embodiment of the invention. Referring to FIG. 2 , the switchable panel 200 includes a first flexible substrate 210 , a second flexible substrate 220 , a first electrode layer 230 , a second electrode layer 240 , a plurality of spacers 250 , and a spacer Optical medium 260.

The first flexible substrate 210 faces the second flexible substrate 220. The first electrode layer 230 is disposed on the first flexible substrate 210 and located between the first flexible substrate 210 and the second flexible substrate 220 . The second electrode layer 240 is disposed on the second flexible substrate 220 and located between the first flexible substrate 210 and the second flexible substrate 220 . The spacer 250 is disposed between the first flexible substrate 210 and the second flexible substrate 220. The optical medium 260 is disposed between the first electrode layer 230 and the second electrode layer 240 , and the optical medium 260 is filled between the spacers 250 . In addition, the first flexible substrate 210 and the second flexible substrate 220 may be assembled by a frame glue 270, and the optical medium 260 may be sealed to the first flexible substrate 210 and the second flexible substrate. 220 and the space surrounded by the frame glue 270.

The first electrode layer 230 and the second electrode layer 240 are used to provide a driving electric field to drive the optical medium 260 to provide corresponding optical characteristics. For example, the optical medium 260 employed in the switchable display panel 200 is, for example, a liquid crystal material. The driving electric field provided by the first electrode layer 230 and the second electrode layer 240 can change the optical axis direction provided by the optical medium 260 such that the optical medium 260 allows only light of a particular polarization direction to pass or allows all of the light to pass. Alternatively, the driving electric field provided by the first electrode layer 230 and the second electrode layer 240 may change the refractive index of the optical medium 260 such that the light is deflected after passing through the switchable panel 200 to travel toward a specific display direction or complete the light. Directly through the switchable panel 200 without deflection.

As can be seen from FIG. 2, the switchable panel 200 substantially seals an optical medium 260 such as a liquid crystal material between the first flexible substrate 210 and the second flexible substrate 220 to provide a specific liquid crystal material. Optical properties. In particular, optical medium 260 is substantially in a space that is in a vacuum. In addition, the materials of the first flexible substrate 210 and the second flexible substrate 220 may include polycarbonate (Polycarbonate, PC), polyethylene terephthalate (PET), and polyimide (Polyimide). , PI), Polyethersulfone (PES), Cyclic Olefin Copolymer (COC), Cyclo Olefin Polymer (COP), combinations thereof or other polymeric materials.

These materials have characteristics of light weight and thin thickness compared to the glass substrate used in the related art. Therefore, when the switchable panel 200 is applied to the display device 10, the overall weight can be effectively reduced and the overall volume can be reduced. In an embodiment, the first flexible substrate 210 and the second flexible substrate 220 have a thickness of 20 micrometers to 200 micrometers. In contrast to the glass substrates used in the related art, which are generally larger than 200 micrometers, the design of this embodiment is much thinner.

However, since the substrate made of the above polymer material is flexible, the Young's modulus of the first flexible substrate 210 and the second flexible substrate 220 of the present embodiment is, for example, 2 GPa to 3 GPa. The switchable panel 200 is likely to be in a situation where the internal and external pressures are inconsistent under the influence of external pressure such as atmospheric pressure. At this time, the first flexible substrate 210 and the second flexible substrate 220 are likely to exhibit a curved state, which causes the optical medium 260 to exhibit thickness unevenness.

In general, in the display device 10 , the display image of the display panel 100 needs to have a stereoscopic display effect by the function of the switchable panel 200 , and the switchable panel 200 is located in front of the display panel 100 . Therefore, the optical characteristics provided by the switchable panel 200 affect the display effect of the display device 10. The unevenness in thickness of the optical medium 260 described above will adversely affect the display quality of the display device 10. Therefore, in order to provide the desired optical characteristics, the present embodiment needs to maintain the first flexible substrate 210 and the second flexible substrate 220 in a flat (substantially non-bending) state to avoid uneven thickness of the optical medium 260. phenomenon. Therefore, this embodiment proposes to arrange the spacers 250 in a specific layout manner.

Specifically, the spacers 250 of the present embodiment are disposed such that the adjacent two spacers 250 are separated by a separation distance d, and the separation distance d is 20 micrometers to 200 micrometers, or even less than 150 micrometers, wherein the separation distance d is Refers to the minimum distance between adjacent two spacers 250 near each other. At such an installation density, the distance G between the first flexible substrate 210 and the second flexible substrate 220 remains substantially uniform. That is, the spacers 250 are used to maintain the distance G between the first flexible substrate 210 and the second flexible substrate 220 to be substantially a uniform gap thickness. As such, the optical medium 260 has a substantially uniform thickness to provide desirable optical characteristics.

In addition, it is to be noted that separating the spacers 250 by an appropriate separation distance d also contributes to improving the manufacturing yield of the switchable panel 200. In particular, the optical medium 260 is generally a material having a certain fluidity (such as a flowable liquid crystal material). During the fabrication process of filling the optical medium 260 between the first flexible substrate 210 and the second flexible substrate 220, the spacers 250 tend to block the flow of the optical medium 260. Once the spacing distance d of the spacers 250 is insufficient, the optical medium 260 may not be sufficiently filled between the spacers 250 to cause a defect in the switchable panel 200. Therefore, the present embodiment allows the separation distance d to be 20 micrometers to 200 micrometers, or even less than 150 micrometers, to allow the optical medium 260 to flow between the spacers 250 and effectively maintain the first flexible substrate 210 and the second flexible layer. The distance G between the substrates 220.

In general, as can be seen from FIG. 2, the area enclosed by the sealant 270 is the set area of the optical medium 260. The optical medium 260 is present in this area to provide a specific optical effect, and thus the area enclosed by the sealant 270 may be referred to as the active area of the switchable panel 200. FIG. 3 illustrates a layout of a spacer in a active area in a switchable panel according to an embodiment of the invention. Referring to FIG. 3 , the active area A shown here refers to the area enclosed by the sealant 270 in the switchable panel 200 of FIG. 2 , that is, the presence of the optical medium 260 affects the display effect of the display device 10 . region.

Here, regarding the spacers 250 arranged in an array in the active area A, the separation distance d1 between the adjacent two spacers 250 in the Y direction may be different from the interval between the adjacent two spacers 250 in the X direction. The separation distance is d2. However, the separation distance d1 and the separation distance d2 are both set in the range of 20 micrometers to 200 micrometers, or even less than 150 micrometers. It is worth mentioning that although FIG. 3 illustrates that the spacers 250 are regularly arranged in an array, in other embodiments, the arrangement of the spacers 250 may exhibit an irregular pattern.

In addition, referring to FIG. 2 and FIG. 3 , the spacer 250 is substantially a columnar structure and is supported between the first flexible substrate 210 and the second flexible substrate 220 . The height 250H of each of the spacers 250 may be from 3 micrometers to 5 micrometers. However, the height 250H of the spacers 250 may be adjusted according to the desired optical effect and the material of the optical medium 260. The invention is not limited thereto.

Generally, the material of the spacer 250 may be a photoresist material, which can be formed into a specific shape by a lithography process. Therefore, the change of the shape of the spacer 250 does not complicate the process, and can be variously designed. Adjusted for demand. The spacer 250 can be formed on one of the first flexible substrate 210 and the second flexible substrate 220, and then the first flexible substrate 210 and the second flexible substrate 220 are sealed by the frame. The 270 sets are stacked together such that the columnar spacers 250 are supported between the first flexible substrate 210 and the second flexible substrate 220. In other words, one end of each spacer 250 is substantially fixed to one of the first flexible substrate 210 and the second flexible substrate 220 and the other end is substantially detachably abuttable against the first flexible substrate 210 and The other of the second flexible substrate 220.

As can be seen from FIG. 2, the area occupied by the spacer 250 itself cannot be filled with the optical medium 260. Therefore, in order to provide the switchable panel 200 with the desired optical characteristics, the cross-sectional width 250W of each spacer 250 parallel to the first flexible substrate 210 or the second flexible substrate 220 may be 5 micrometers to 25 micrometers. In addition, from the top view of FIG. 3, the area ratio of the total area of the cross section 250A of the spacer 250 parallel to one of the first flexible substrate 210 and the second flexible substrate 220 to the active area A may be 0.05%. To 5%. Layout of the spacers 250 in this manner maintains the distance G between the first flexible substrate 210 and the second flexible substrate 220 illustrated in FIG. 2 at a substantially fixed gap thickness. In addition, such a layout also maintains proper fluidity during filling of the optical medium 260 between the first flexible substrate 210 and the second flexible substrate 220 to avoid incomplete filling of the optical medium 260.

Each spacer 250 is illustrated in FIG. 2 as a structure having a uniform cross-sectional width of 250 W, and is depicted in the upper view of FIG. 3 as a structure having a circular cross-section 250A. However, this embodiment is not limited thereto. For example, Figures 4A-4D illustrate the design of various spacers. In one embodiment, as shown in FIG. 4A, a cross-sectional area of the spacer 252 parallel to the first flexible substrate or the second flexible substrate is substantially flexible from the first flexible substrate to the second flexible substrate. The substrate is gradually changed. That is, the spacer 252 has an island shape. As can be seen from FIG. 4B, a cross-sectional area of the spacer 254 parallel to the first flexible substrate or the second flexible substrate can be substantially rectangular. Additionally, according to Figure 4C, the spacers 256 may optionally have a graded width under a rectangular cross-sectional area design. Furthermore, as can be seen from FIG. 4D, the cross-sectional area of the spacer 258 can be irregular, such as a gourd shape or other shape. In general, in the switch panel 200 of FIG. 2 , each of the spacers 250 may have any of the appearances illustrated in FIG. 4A to FIG. 4D , and the shapes of the plurality of spacers 250 may be different or the same.

In summary, the present invention utilizes the distribution of spacers to maintain the distance between the two flexible substrates while leaving the flow of optical media between the substrates between the spacers without excessive limitations. Therefore, the switchable panel can be provided with light and thin characteristics, and the optical medium of the switchable panel can have a substantially uniform thickness. Even if the flexible substrate is subjected to different internal and external pressures, the optical characteristic portion provided by the optical medium of the switchable panel may be affected. In this way, the display device including the switchable panel can have an ideal display effect in addition to the display functions of the plane and the stereo.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧ display device

100‧‧‧ display panel

100A‧‧‧ display surface

110‧‧‧First substrate

120‧‧‧second substrate

130‧‧‧Display media

200‧‧‧Switchable panel

210‧‧‧First flexible substrate

220‧‧‧Second flexible substrate

230‧‧‧First electrode layer

240‧‧‧Second electrode layer

250, 252, 254, 256, 258‧‧ ‧ spacers

250A‧‧‧ area

250H‧‧‧ Height

250W‧‧‧section width

260‧‧‧Optical media

270‧‧‧Box glue

300‧‧‧Optical adhesive

A‧‧‧active area

d, d1, d2, G‧‧‧ distance

X, Y‧‧ direction

FIG. 1 is a schematic side view of a display device according to an embodiment of the invention.

2 is a cross-sectional view of a switchable panel in accordance with an embodiment of the present invention.

FIG. 3 illustrates a layout of a spacer in a active area in a switchable panel according to an embodiment of the invention.

4A-4D illustrate the design of various spacers.

250. . . Interstitial

250A. . . area

250W. . . Section width

A. . . Active zone

D1, d2. . . distance

Claims (14)

A display device includes: a display panel having a display surface; and a switchable panel located in front of the display surface and the switchable panel includes an active area, wherein the switchable panel includes: a first a flexible substrate; a second flexible substrate facing the first flexible substrate; a first electrode layer disposed on the first flexible substrate and located on the first flexible substrate and the first flexible substrate Between the two flexible substrates; a second electrode layer disposed on the second flexible substrate and located between the first flexible substrate and the second flexible substrate; a plurality of spacers, Between the first flexible substrate and the second flexible substrate, two adjacent spacers are separated by a separation distance, the separation distance is 20 micrometers to 200 micrometers, and the spacers are parallel to the The ratio of the total area of the cross section of the first flexible substrate and the second flexible substrate to the active area is 0.05% to 5%; and an optical medium disposed on the first electrode layer and the first Between the two electrode layers, and filled between the spacers. The display device of claim 1, wherein the separation distance is no more than 150 micrometers. The display device according to claim 1, wherein the first flexible substrate and the second flexible substrate have a Young's modulus of 2 GPa to 3 GPa. The display device of claim 1, wherein the display device The thickness of the first flexible substrate and the second flexible substrate is from 20 micrometers to 200 micrometers. The display device of claim 1, wherein each of the spacers has a height of from 3 micrometers to 5 micrometers. The display device of claim 1, wherein each of the spacers is substantially a column spacer. The display device of claim 6, wherein each of the spacers is substantially parallel to a cross-sectional area of the first flexible substrate or the second flexible substrate. The display device of claim 6, wherein each of the spacers has a cross-sectional width of 5 micrometers to 25 micrometers parallel to the first flexible substrate or the second flexible substrate. The display device of claim 1, wherein one end of each of the spacers is substantially fixed to one of the first flexible substrate and the second flexible substrate, and the other end substantially abuts The other of the first flexible substrate and the second flexible substrate. The display device of claim 1, wherein the material of the spacers comprises a photoresist material. The display device of claim 1, wherein the distance between the first flexible substrate and the second flexible substrate is substantially uniform. The display device of claim 1, wherein the spacers are used to maintain a substantially uniform gap thickness between the first flexible substrate and the second flexible substrate. The display device of claim 1, wherein the material of the first flexible substrate and the second flexible substrate comprises polycarbonate (Polycarbonate, PC), polyethylene terephthalate (Polyethylene) Terephthalate, PET), Polyimide (PI), Polyethersulfone (PES), Cyclic Olefin Copolymer (COC), Cyclo Olefin Polymer (COP) or combination. A display device comprising: a display panel having a display surface; and a switchable panel located in front of the display surface, wherein the switchable panel comprises: a first flexible substrate; a second flexible The substrate is opposite to the first flexible substrate; a first electrode layer is disposed on the first flexible substrate and located between the first flexible substrate and the second flexible substrate; a second electrode layer disposed on the second flexible substrate between the first flexible substrate and the second flexible substrate; a plurality of spacers disposed on the first flexible substrate and the Between the second flexible substrates, two adjacent spacers are separated by a separation distance of 20 micrometers to 200 micrometers; and an optical medium is disposed on the first electrode layer and the second electrode layer Between and between the spacers, wherein a cross-sectional area of each of the spacers parallel to the first flexible substrate or the second flexible substrate is substantially by the first flexible The substrate to the second flexible substrate is gradually changed.