KR20230124348A - Foldable Display of Preventing Folding Deformation - Google Patents

Abstract

The foldable display includes a display panel, a protection panel that forms and combines a fluid pocket on the front of the display panel, a sealing member that seals the fluid pocket by combining the display panel and the flexible protection panel along the edge, and a flexible display panel and a flexible display panel in the folding area. A fluid pump coupled to the rear surface of the display panel to selectively inject or discharge fluid into or out of the fluid pocket, and a driving member that drives the fluid pump.

Description

Foldable display that blocks folding deformation {Foldable Display of Preventing Folding Deformation}

The present invention relates to a foldable display, and more particularly, to a foldable display capable of preventing deformation of a folding part.

Recently, a foldable display using a flexible display panel is in the limelight. The foldable display is convenient to carry when folded and can realize a large screen when unfolded (Unfolding or Release), so it is suitable for mobile devices such as mobile phones, ultra-mobile PCs, e-books, and e-newspapers. It is also widely applied to televisions and monitors.

1A illustrates a folded state of a foldable display according to the prior art.

As shown in FIG. 1A , a conventional foldable display 10 usually has a structure in which a flexible display panel 11, a point/adhesive layer 12, and a flexible protection panel 13 are stacked. When the conventional foldable display 10 having such a structure is folded, deformation may occur due to stress of the point/adhesive layer 12 in the folding region. If stress is accumulated while folding and releasing are repeated, the restoring force of the point/adhesive layer 12 may rapidly drop in the folding region.

1B illustrates a release state of a foldable display according to the prior art.

As shown in FIG. 1B, when the restoring force of the point/adhesive layer 12 decreases in the folding region due to repetition of folding and release, deformation may occur in the point/adhesive layer 12 in the folding region. The deformation of the point/adhesive layer 12 affects the flexible display panel 11 and the flexible protection panel 13, so that the flexible display panel 11 and the flexible protection panel 13 are also deformed, for example, wrinkles, bends, etc. can cause Such deformation of the folding area may reduce the visibility and product value of the foldable display, and further deteriorate the restoring force of the point/adhesive layer 12 to lose the foldable function.

[Prior literature]

1. Korean Patent Publication No. 10-2020-0033001 (foldable electronic device including integral adhesive layer and adhesive prevention unit)

2. Korean Patent Publication No. 10-2021-0044337 (display device)

The present invention is intended to solve the problems of the prior art, and provides a foldable display capable of fundamentally blocking deformation (wrinkles, bends, etc.) of the folding area caused by deformation of the point/adhesive layer in the folding area even when folding/release is repeated. want to provide

The foldable display of the present invention to achieve this object may include a flexible display panel, a flexible protection panel, a sealing member, a fluid pump, a driving member, and the like.

The flexible display panel may be an OLED display panel or the like.

The flexible protection panel may be combined while forming a fluid pocket on the front surface of the flexible display panel.

The sealing member may be coupled along edges of the flexible display panel and the flexible protection panel to seal the fluid pocket.

The fluid pump may be coupled to the flexible display panel and the rear surface of the flexible display panel in the folding area to selectively inject or discharge fluid into the fluid pocket.

The driving member may drive the fluid pump.

In the foldable display of the present invention, the fluid pump may include a fluid guide, a pump cylinder, and a pump gear.

The fluid guide may pass through the flexible display panel and communicate with the fluid pocket and the outside of the rear surface of the flexible display panel.

The pump cylinder may include a plurality of teeth spaced apart from each other in the longitudinal direction on an outer surface of the fluid guide to seal the interior of the fluid guide.

The pump gear may be coupled to the pump cylinder outside the rear surface of the flexible display panel to move the pump cylinder.

In the foldable display of the present invention, the driving member may include a driving body, a driving gear, and the like.

The driving body may pivot around the folding area.

In the folding area, one side of the driving gear is coupled to the driving body and the other side is coupled to the pump gear, so that the pump gear can be axially rotated according to the axial rotation of the driving body.

In the foldable display of the present invention, the fluid pump may inject fluid into the fluid pocket when folded and discharge fluid from the fluid pocket when released.

In the foldable display of the present invention, the fluid may be air.

In the foldable display of the present invention, the fluid may be a liquid having a refractive index of 1.0 to 1.7.

In the foldable display of the present invention, the fluid may be a liquid having a refractive index of 1.4 to 1.6.

The foldable display of the present invention having such a configuration does not use a point/adhesive layer to couple the flexible display panel and the flexible protection panel, and forms a fluid pocket between the flexible display panel and the flexible protection panel to selectively fold/release the foldable display. By injecting and discharging fluid into the fluid pocket, it is possible to fundamentally block the deformation (wrinkle, bend, etc.) of the folding area of the foldable display caused by the point/adhesive layer.

In addition, the foldable display of the present invention can reduce the stress or pressure applied to the flexible display panel or the flexible protection panel to almost zero by inserting air, fluid, etc. into the fluid pocket between the flexible display panel and the flexible protection panel. Therefore, the folding performance and durability of the foldable display can be greatly improved.

1A illustrates a folded state of a foldable display according to the prior art.
1B illustrates a release state of a foldable display according to the prior art.
2a and 2b are cross-sectional and perspective views illustrating a folded state of a foldable display according to the present invention.
3a and 3b are cross-sectional and perspective views illustrating a release state of a foldable display according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2a and 2b are cross-sectional and perspective views illustrating a folded state of a foldable display according to the present invention.

As shown in FIGS. 2A and 2B, the foldable display of the present invention includes a flexible display panel 110, a sealing member 120, a flexible protection panel 130, a fluid pump 140, a driving member 150, and the like. can be configured.

The flexible display panel 110 generates an image, and may be an LCD display panel or an OLED display panel.

The flexible display panel 110 may include a pixel electrode, a pixel defining layer, a display layer, a counter electrode, an encapsulation layer, and the like.

The pixel electrode causes the display layer to emit light by applying a voltage or current to the display layer, and may be electrically connected to the drain electrode of the thin film transistor TFT.

The pixel defining layer may define a pixel area by exposing a pixel electrode.

The display layer emits color and may include, for example, a liquid crystal layer or an organic light emitting layer.

The opposite electrode may be disposed on the pixel defining layer and the display layer. The counter electrode may serve as, for example, a common electrode or a cathode of an image display device.

The encapsulation layer protects components of the lower display panel and may be stacked on the opposite electrode.

In addition, the flexible display panel 110 may include a spacer or the like.

The sealing member 120 is coupled along the edge of the flexible display panel 110 and the flexible protection panel 130 to form and seal the fluid pocket A, for example, an adhesive or adhesive film composed of an epoxy resin composition can be used. The epoxy resin composition may include an acrylic resin containing an epoxy group, an inorganic filler, a curing agent, and the like.

The sealing member 120 may bond an adhesive film having an empty central region between the flexible display panel 110 and the flexible protection panel 130 through thermal curing or photo curing.

The flexible protection panel 130 protects the flexible display panel 110, and a window film in the form of a film coupled to the front of the flexible display panel 110 may be used. The window film may be, for example, a film in which a hard coating layer is laminated on a base layer.

The substrate layer may use a transparent polymer film so that it can be applied to a flexible display, for example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl Cellulose, polyester, polystyrene, polyamide, polyetherimide, polyacrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, poly Vinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate and the like can be used.

The hard coating layer may include a fluorine-based polymerizable compound, a non-fluorene-based polymerizable compound, a thiophene-based antistatic agent, a photoinitiator, a solvent, and the like. The hard coating composition may be formed through a curing process such as UV curing after being applied to the base layer.

The fluid pump 140 selectively injects or discharges fluid into the fluid pocket A, and can be coupled to the flexible display panel 110 and its rear in a folding area.

The fluid pump 140 may be composed of a fluid guide 141, a pump cylinder 142, a pump gear 143, and the like.

The fluid guide 141 guides the movement of fluid, and may be configured in a form in which the fluid pocket A communicates with the outside of the rear surface of the flexible display panel 110 .

The fluid guide 141 may have a shape penetrating the flexible display panel 110, for example, a tube such as a cylinder or a square cylinder. The tube-shaped fluid guide 141 may be inserted into and fixed to a through hole formed in the flexible display panel 110, that is, a guide coupling hole H.

The pump cylinder 142 is to forcibly move the fluid, and can be inserted into the fluid guide 141 to slide along the longitudinal direction.

The pump cylinder 142 may be configured in a shape such as a cylinder or a square column corresponding to the inner shape of the fluid guide 141, and its outer surface is in close contact with the inner surface of the fluid guide 141 to lengthen the fluid guide 141. direction can be closed.

The pump cylinder 142 may have a plurality of longitudinally spaced teeth on its outer surface for longitudinal movement. The teeth may linearly move the pump cylinder 142 according to the axial rotation of the pump gear 143 by being coupled to the pump gear 143 to be described later.

The pump gear 143 linearly moves the pump cylinder 142 in the longitudinal direction within the fluid guide 141, and may be configured in the form of a gear having a plurality of teeth along the outer surface.

One side of the pump gear 143 is geared to the driving gear 152 of the driving member 150 and the other side is geared to the pump cylinder 142 so that the axial rotation of the driving gear 152 is linear to the pump cylinder 142. It can be delivered by moving.

As shown in FIGS. 2A and 2B, the fluid pump 140 transfers the fluid inside the fluid guide 141 to the inside of the fluid pocket A while the pump cylinder 142 moves in the direction of the fluid pocket A during folding. can be injected with

The fluid injected by the fluid pump 140 may be air or liquid. When the fluid is a liquid, in order to block or minimize image quality distortion due to the refraction phenomenon, a material having a refractive index similar to that of the material constituting the external air, the flexible display panel 110, the flexible protection panel 130, etc. It is preferred to use a fluid. Since the refractive index of external air is 1.0 and the refractive index of transparent materials constituting the flexible display panel 110 or the flexible protection panel 130, for example, transparent glass and transparent plastic, is usually 1.4 to 1.6, the present invention has a refractive index of It is preferable to use a liquid of 1.0 to 1.7, and more preferably, a fluid of 1.4 to 1.6 close to the refractive index of transparent glass or transparent plastic constituting the flexible display panel 110 or the flexible protection panel 130 may be used.

The driving member 150 drives the fluid pump 140, and may include a driving body 151, a driving gear 152, a driving cover 153, and the like.

The driving body 151 supports the rear of the flexible display panel 110 while having a folding area in the folding area, and can be composed of two driving panels that pivot around the folding area. The driving panel may be configured in a plate shape.

The driving gear 152 is coupled to the pump gear 143 to rotate the pump gear 143, and may be provided at an end of the folding region of the driving body 151.

The drive gear 152 may have a plurality of teeth on the outer surface to be coupled to the pump gear 143, in this case, when the drive body 151 rotates around the folding area, the drive gear 152 rotates the shaft. And, at this time, the toothed pump gear 143 may also rotate axially. Through the process of transmitting such rotational force, the fluid pump 140 is operated by folding of the drive body 151, that is, shaft rotation.

The drive cover 153 covers a space separated from the drive body 151 in the folding area, and may be in the form of a bellows that can be freely contracted.

It may be desirable to position the inner surface of the driving cover 153 rearward than the maximum protruding height when the pump cylinder 142 moves backward to the maximum so as not to hinder the rearward movement of the pump cylinder 142 .

As shown in FIGS. 2A and 2B , the foldable display of the present invention having such a configuration is at the end of the driving body 151 during the folding process of changing the driving body 151 from a release position, that is, a flat position to a folding position. The provided driving gear 152 may pivot in a counterclockwise direction (refer to FIG. 2A ) in the folding area. At this time, the pump gear 143 teeth-coupled to the driving gear 152 rotates in the opposite direction to the driving gear 152, that is, in a clockwise direction (refer to FIG. 2A).

When the pump gear 143 rotates clockwise, the pump cylinder 142 coupled with teeth to the pump gear 143 moves upward (refer to FIG. 2A) while reducing the internal space of the fluid guide 141. there is. At this time, the fluid inside the fluid pocket (A) may move to the fluid pocket (A) and increase the fluid inside the fluid pocket (A).

During the folding process, the space between the flexible display panel 110 and the flexible protection panel 130 further widens in the folding area, and at this time, most of the fluid fills the fluid pocket A in the folding area, thereby protecting the flexible display panel 110 and the flexible protection panel 130. The flexible protection panel 130 may be supported.

As such, in the folding process, almost no stress is generated in the fluid, and as a result, the fluid does not affect the flexible display panel 110 and the flexible protection panel 130 by stress or pressure. Since the force that deforms the 110 or the flexible protective panel 130 does not act, deformation in the folding area, which has been a problem in the prior art, such as wrinkles and bends, may not be caused.

3a and 3b are cross-sectional and perspective views illustrating a release state of a foldable display according to the present invention.

As shown in FIGS. 3A and 3B, in the release process, that is, when the driving body 151 is unfolded from the folding position to the release position, that is, the flat position, the driving gear 152 provided at the end of the folding region of the driving body 151 It can rotate in a clockwise direction (refer to FIG. 3A). At this time, the pump gear 143 teeth-coupled to the driving gear 152 may pivot in the opposite direction to the driving gear 152, that is, in a counterclockwise direction (refer to FIG. 3A).

When the pump gear 143 rotates counterclockwise, the pump cylinder 142 coupled with teeth to the pump gear 143 moves downward (see FIG. 3A) to form a space inside the fluid guide 141. do. At this time, the fluid inside the fluid pocket (A) moves to the inner space of the fluid guide 141, and as a result, the fluid inside the fluid pocket (A), especially the fluid in the folding area, is reduced and the flexible display panel 110 and The space between the flexible protective panels 130 may be narrowed and closely adhered to each other.

Even during this release process, since no stress is generated in the fluid and the fluid does not exert stress or pressure on the flexible display panel 110 and the flexible protection panel 130, the flexible display panel 110 or the flexible Deformation (wrinkles, bends, etc.) may not be caused to the protection panel 130 .

In the above description, the in-folding form has been described as an example, but the foldable display blocking the folding deformation of the present invention is not limited to this form, and out-folding, Z-folding ) and the like, it can be applied to all folding shapes having a folding (or bending) region on at least one surface.

In the above, the present invention has been described as examples, which are for illustrating the present invention. Those skilled in the art will be able to change or modify these embodiments in other forms. However, since the scope of the present invention is defined by the claims below, such variations or modifications may be construed as being included in the scope of the present invention.

10: foldable display 11,110: flexible display panel
12: point / adhesive layer 120: sealing member
13,130: flexible protection panel 140: fluid pump
141: fluid guide 142: pump cylinder
143: pump gear 150: driving member
151: drive body 152: drive gear
153: driving cover A: fluid pocket
H: guide coupling hole

Claims (7)

flexible display panel;
a flexible protection panel coupled to the front surface of the flexible display panel while forming a fluid pocket;
a sealing member coupled along edges of the flexible display panel and the flexible protection panel to seal the fluid pocket;
a fluid pump coupled to the flexible display panel and a rear surface of the flexible display panel in a folding area to selectively inject or discharge fluid into the fluid pocket;
A foldable display that blocks folding deformation, including a driving member that drives the fluid pump. The method of claim 1, wherein the fluid pump
a fluid guide passing through the flexible display panel and communicating the fluid pocket with the outside of the rear surface of the flexible display panel;
A pump cylinder having a plurality of teeth formed spaced apart along the longitudinal direction on an outer surface and moving sealantly inside the fluid guide;
A foldable display that blocks folding deformation, including a pump gear coupled to the pump cylinder from the outside of the rear surface of the flexible display panel to linearly move the pump cylinder in the fluid guide. The method of claim 1, wherein the driving member
A driving body that rotates around the folding area as a boundary;
A foldable display that blocks folding deformation, including a driving gear in a folding area, one side of which is coupled to the driving body and the other side is coupled to the pump gear to pivot the pump gear according to the rotation of the driving body. The method of any one of claims 1 to 3, wherein the fluid pump
A foldable display blocking deformation of folding, in which fluid is injected into the fluid pocket when folded, and fluid is discharged from the fluid pocket when released. 5. The method of claim 4, wherein the fluid is
A foldable display that blocks air and folding deformation. 5. The method of claim 4, wherein the fluid is
A liquid with a refractive index of 1.0 to 1.7, a foldable display that blocks folding deformation. 7. The method of claim 6, wherein the fluid is
A liquid with a refractive index of 1.4 to 1.6, a foldable display that blocks folding deformation.

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