JP2003330384A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hold an image display panel having flexibility by imparting curvature to the panel. <P>SOLUTION: The image display device is provided with a display panel which has flexibility, a casing which is externally mounted with the display panel and has flexibility and a flexible material which holds the display panel and the casing as an integral unit to a desired shape. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly to a flexible image display device.

[0002]

2. Description of the Related Art As a space-saving image display device for displaying image information, a flat panel image display device (FPD, Flat Panel Dielectric) is used.
splay) has rapidly spread in place of the conventional CRT (Cathode Ray Tube).

Most FPDs represented by liquid crystal display devices are equipped with a thin film transistor (TFT) for each pixel in order to display a high-definition image.
Since this TFT is formed using a semiconductor process at 200 ° C. or higher, a glass substrate is usually used from the viewpoint of heat resistance.

A liquid crystal display device uses a liquid crystal display panel in which a glass substrate with a TFT is used on one side and liquid crystal is injected into a cell in which two glass substrates are bonded and sealed, and polarizing plates are provided in front of and behind the substrates. There is. There are a type in which a flat illumination device such as a backlight or a front light is combined on the back or front of the display surface, and a reflection type in which an illumination unit for displaying by external light reflection is not provided. Further, a light-transmitting touch panel may be provided on the front surface of the display screen of the liquid crystal display device as an information input mechanism.

In recent years, attention has been paid to an organic EL display using an organic EL as a light emitting element as an FPD using a TFT.

A polymer film that is lighter and more flexible than a glass substrate may be used as the FPD substrate. Further, there is a method of providing flexibility by forming a TFT on a glass substrate and then physically or chemically etching the glass substrate to reduce the substrate thickness.

As means for adjusting the curvature of a flexible FPD and maintaining it in a curved shape, Japanese Patent Laid-Open No. 10-2687
Reference numeral 90 discloses a mechanism for adjusting and holding a curved surface state by using an adjusting mechanism in which a liquid crystal display panel is attached to a flat backlight. In addition, JP-A-7-140451
Discloses a means for adjusting and holding a curved surface shape by heating and cooling, using a polyurethane polymer having a shape memory function or a shape recovery function as a substrate of a liquid crystal display panel. Further, as means for limiting the radius of curvature, Japanese Patent Laid-Open No. 11-
15397 discloses means for providing a guide roller to limit the folding radius of curvature.

[0008]

The conventional non-flexible FPD is a plate-shaped rigid body, and therefore has the disadvantage that it does not flex naturally like paper and does not fit even if held in the hand. is doing.

On the other hand, when the FPD is flexible, it is necessary to provide a mechanism for limiting the curvature to a certain extent in order to prevent damage to the components.

Generally, not only in the FPD but also in the image display device, when the image is reflected on the display screen when used under a bright place, the display quality is remarkably deteriorated.

On the other hand, as shown in FIG.
If is a plane, the reflected range is the angle 2103. Therefore, for example, the direct incident light from the illumination 2104 above the user 2105's head is reflected by the flat screen 2101.
Then, it is recognized as a reflection at the position of the user 2105 (right in FIG. 23).

[0012]

In order to solve the above-mentioned problems, the present invention provides a flexible display panel, a flexible housing for covering the display panel, a flexible display panel, and the display panel and the display panel. Provided is an image display device including a flexible material that holds a housing in a desired shape.

Here, the flexible member may be provided along a pair of sides of the display panel to hold the display panel and the housing in a state of being bent along the sides. .

Further, the flexible material is 4 of the display panel.
The display panel and the housing may be provided along the side and held in a bent state.

The flexible material is provided along the back surface of the display panel, and can hold the display panel and the housing in a bent state.

The flexible material may be a flexible tube.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The image display device according to the present invention will be described in detail below. However, it goes without saying that the configuration of the present invention is not limited to the embodiments described below, and that various configurations of the respective portions of the configurations described in the embodiments and examples of the invention can be adopted. . (Embodiment 1) In this embodiment, as shown in FIG. 1, the display panel 102 is covered with a housing 103. Here, FIG. 1A is an explanatory plan view of the image display device of the present embodiment, and FIG. 1B is a cross-sectional view taken along the alternate long and short dash line AA in FIG.

In the casing 103, the non-flexible material 101 having no flexibility and the shape of the image display device are changed,
Moreover, a flexible member 104 for fixing is provided. A combination of the non-flexible material 101 and the flexible material 104 is arranged in a frame shape so as to surround the display panel 102, and also serves to protect the side surface of the image display panel.

Here, the flexible member 104 can be flexed by an external force, and further retains the curvature set by the user. Further, it is desirable that the flexible material 104 also has a function of limiting curvature and preventing damage to the internal structure of the display panel 102 and the like. In this way, by appropriately adjusting the flexible material 104, both flexibility and protection of the display screen can be achieved. In addition, flexibility can be imparted to only a part of the housing 103.

The flexible member 104 has a columnar shape or a plate shape, and is arranged on the side surface or the bottom surface of the display panel 102.

The shape and material of the flexible material 104 are a flexible tube, a flexible metal such as copper or lead, a plastic made of polyimide or BCB (benzocyclobutene), a hybrid material in which a plastic material and a metal are laminated. Can be used. In the case of a hybrid material, it is possible to give anisotropy to the bending rigidity by giving anisotropy in the stacking direction. It is also possible to increase the bending rigidity in the direction to increase the rigidity.

Further, as the flexible material 104, Ni-T is used.
By using a metal material having a shape memory property such as an i-based alloy or a Cu-Zn-Al-based alloy for the support material, it is possible to easily restore the original curvature. The use of shape memory alloys not only enables highly accurate restoration, but also has the advantage that the restoration operation is easy because no external force is required. For example, it becomes possible to perform restoration by operating a switch.

The curvature holding force required for the flexible member 104 is determined by the bending rigidity of the panel 102 and the bending rigidity of the flexible member 104 itself. That is, the curved surface is held by setting the curvature holding force larger than the restoring force derived from the bending rigidity of both.

FIG. 2 shows an example of the relationship between the curvature when an external force is applied to set a curved surface and the actually held curvature. Here, the horizontal axis represents the curvature when an external force is applied, and the vertical axis represents the curvature that is retained when the external force is stopped. In the figure, the dotted line extending at 45 degrees is where the curvature when an external force is applied matches the retained curvature, and shows the case where the shape of the image display device does not change even if the external force is removed after the external force is applied. ing. However, in many cases, due to the restoring force of the panel and the support, when the external force is removed, the image display device returns a little when the external force is applied. It is held at a slightly smaller value than.

Here, by considering that the maximum curvature of the support material is smaller than the maximum curvature that can be restored without breaking the panel (maximum allowable curvature of the panel), it is possible to prevent the panel from being broken due to excessive bending. It is important to protect.

The maximum curvature of the support material can be set by using the physical properties of the support material itself, by mechanical design, or by providing a stopper. As an example of the method of utilizing the physical properties, it is considered that the bending rigidity is set to an appropriate value by appropriately selecting the thickness and the material. Also,
As a method using the mechanical design means, a method of using a flexible tube having a desired maximum curvature as a support material can be considered. Furthermore, as an example of the stopper, a method of utilizing the maximum curvature of the housing as an indirect stopper mechanism is conceivable.

It is preferable to use liquid crystal or organic EL for the display panel 102 in terms of flatness and thinning.

When the image display panel 102 is a liquid crystal,
It is desirable to have a flexible flat illumination device. A planar lighting device having flexibility includes, for example, a light source and a light guide plate, and a fluorescent tube or an LED on the end surface of the light guide plate.
There is a side light type in which a light source is arranged and which imparts flexibility to a light guide plate. Alternatively, a direct type in which an EL light emitting surface is provided on the entire surface using a plastic substrate can be used.

Further, a flexible light-transmitting touch panel may be provided on the image display panel. The flexibility of the touch panel can be realized by using a plastic substrate.

By the way, due to the bending operation for the entire image display device, a displacement distortion occurs between the laminated components.
Therefore, it is desirable to provide a mechanism capable of absorbing strain. For example, the flexible material 104 and the display panel 102
The display panel 10 is not fixed on all four sides.
It is advisable to provide a guide mechanism in which one side or two vertices 2 are fixed and the extra side is free, and the strain generated by the bending operation is displaced along the guide. On this occasion,
Needless to say, it is desirable to centrally arrange non-flexible components (circuit board, fluorescent tube, etc.) on the fixed side and keep the periphery of the fixed part inflexible in terms of rigidity, positional accuracy, and component connection reliability. There is also no.

With such a shape, it is possible to improve the bending rigidity of the end portion where stress is easily concentrated and is easily damaged, and the display screen is made concave while limiting bending in the lateral direction of the screen. It becomes possible to adjust. By limiting bending in the screen short-side direction, it is possible to arrange a member that does not have flexibility in the screen short-side direction, such as a fluorescent tube, and there is a risk of peeling of the joint due to repeated bending Flexible tape (FPC) By arranging the joint portion between the image display panel and the image display panel at the short end portion in a concentrated manner, the joint reliability can be improved.
Needless to say, the same argument holds when the arrangement of the flexible support member is set in the lateral direction and the relationship between the longitudinal direction and the lateral direction of the screen is changed.

Further, although not shown, by disposing the flexible material 104 having flexibility on four sides, it is possible to cope with twisting and bending in a diagonal direction.

Further, the present embodiment will be described in detail with reference to FIGS. FIG. 3 is a plan view of the image display device of the present embodiment, and FIG. 4 is a side view.

Here, a flexible transmissive liquid crystal display panel 201 and a flat illumination device 202 are used to form a flexible image display device. Further, an example in which the flexible tube 302 having a predetermined bending strength is used as the flexible material 104 will be described.

FIG. 5 is a view showing the structure of the flexible tube 302. Here, FIG. 5 (a) is a side view of a tubular flexible tube.
4 is a partial cross-sectional view in which 4 is cut away. Also, FIG.
FIG. 5B is a sectional view of FIG. 5A and shows a cutaway portion of the partial sectional view. Although a partial cross-sectional view is used for the sake of description, the substance is a tube shape.

The flexible tube 302 has a structure in which a plurality of convex rings 1501 are connected. Usually, the flexible tube has a circular cross-sectional structure, but it is more preferable that the flexible tube has an elliptical shape in which the thickness direction d of the panel is shortened. With such a structure, the thickness of the image display device can be taken into consideration. Further, since it is possible to reduce the maximum radius of curvature in the thickness direction (front side of the paper surface of FIG. 3) and simultaneously set the maximum radius of curvature in the parallel direction of the panel surface (left and right direction of the paper surface of FIG. 3).
It is possible to limit the amount of deformation in the in-plane direction, which is undesirable in terms of strength of the image display device, to a small amount. By setting the maximum radius of curvature of the flexible tube 302 to be equal to or larger than the possible radius of curvature of the liquid crystal display panel, the liquid crystal display panel 2 due to excessive bending
01 can be prevented from being damaged.

In this way, as shown in FIG. 6, it is possible to set and maintain the curvature by using the flexible tube 302, and the non-flexible material 101 is bent at its short side end. Absent. Therefore, the short-side end is protected.

FIG. 7 is a sectional view of the transmissive liquid crystal display panel 201 and the sidelight type backlight 202.

In the flexible transmissive liquid crystal display panel 201, a liquid crystal layer 405 is provided between a flexible lower substrate 401 and a flexible upper substrate 402. Seal thickness is 40
3, adjusted by the spacer 404. Further, as in a normal liquid crystal panel, polarizing plates 412 are attached to the top and bottom of the substrate. A flexible tape 410 is joined from an end surface of the lower substrate 401 on which the TFT element 409 and the pixel electrode 408 are formed via a terminal 411, and an image signal and a control signal are supplied from the outside of the panel. For simplicity of illustration, the orientation film, the transparent conductive film formed on the upper substrate, the color filter, etc. are omitted. Here, in order to enable a normal TFT formation process and a liquid crystal injection process while imparting flexibility to the substrates 401 and 402, after performing these processes using a normal glass substrate 406,
The thickness of the substrate is reduced to about 0.1 mm by etching,
The film substrate 407 is attached to maintain the strength. Further, by omitting the film substrate 407 and directly attaching the polarizing plate 412 to the glass substrate 406, further thinning is possible.

The light source unit 601 consisting of the reflector 607 and the fluorescent tube 602 is inflexible in the major axis direction (direction perpendicular to the paper surface). A non-flexible member is used in this direction.

On the other hand, the light guide plate reflector 604, the prism sheet 605, and the scattering sheet 606 usually have flexibility. Therefore, by replacing the light guide plate 603 with a flexible optical material, the backlight is provided with flexibility. It becomes possible to do.

FIG. 8 is a diagram showing a method of fixing the liquid crystal display panel 201 and the backlight 202.

Between the upper casing 203 and the lower casing 103, a frame body 1604 formed by combining a non-flexible material and a flexible material, a backlight 202, and a liquid crystal display panel 201 are sequentially laminated. A bellows 1603 is formed in the center of the housing, and has a structure that absorbs expansion and contraction due to bending.

The drive circuit board 1601 of the non-flexible liquid crystal display panel and the light source unit 601 including the fluorescent tube of the backlight are aligned in one direction and fixed to the casing of the non-flexible portion. Although not shown in the figure for simplification, the main circuit boards other than the drive circuit board are arranged on the drive circuit board (light source) side and at the opposite end, avoiding the central portion where bending occurs.

A guide 1602 is provided on the side of the frame body 1604 opposite to the side on which the liquid crystal display panel 201 is fixed, and the backlight and the liquid crystal display panel slide along the guide when a displacement occurs due to bending. ing.

FIG. 9 is a sectional view schematically showing the relationship between the fixed position of the liquid crystal display panel 201 and the backlight 202 and the displacement strain due to bending. One end face 801 is fixed and the other side 80 is absorbed to absorb the displacement strain 803 due to bending.
Leave 2 open. By disposing the light source, the joint of the liquid crystal panel and the flexible tape (wiring pad of the liquid crystal panel), and the like on the fixed end face 801, distortion due to bending is avoided, and the luminance change of the backlight and the reliability of the joint are improved. Can be secured.

FIG. 10 is a diagram schematically showing the relationship between the light source section and the fixed position from the top of the device.

When making one direction of the screen inflexible, the fixing region 801 is provided in the entire side direction. (Embodiment 2) FIG. 11 shows a flexible tube 302.
Is used on the four sides of the image display device.

In this embodiment, bending and curvature can be set not only in the longitudinal direction of the screen but also in the lateral direction.

The non-flexible material 101 is arranged at the four corners and protects the display panel 02 from bending stress without being bent. FIG. 11A is a plan view of the image display device of this embodiment, and FIG. 11B is an explanatory view seen from the side.

FIG. 12 is a sectional view of the structures of a flexible transmissive liquid crystal display panel 201 and a flat lighting device (backlight) 202 used in this embodiment.

The backlight 202 has a structure in which the EL light emitting layer 413 is sealed with the film substrates 414 and 415, whereby flexibility can be imparted. EL light emitting layer 41
3, a transparent electrode 417 is provided on the upper film substrate 414 and a reflective electrode 418 is provided on the lower film substrate.
Are formed. Since the film substrates 414 and 415 have flexibility, it is possible to realize a backlight that can be bent in any direction.

In the case of being flexible in all directions, FIG.
As shown in, one corner is set as a fixed region 801. (Third Embodiment) Next, a third embodiment will be described.

FIG. 14A is a plan view of a sidelight type backlight having flexibility also in the long axis direction of the light source.
FIG. 14B is a sectional view.

In order to give flexibility to the longitudinal direction of the light source,
The light source unit 601 is configured by an LED light source 701 and a flexible light guide plate 702. Further, the reflector is omitted and the reflective coating surface 703 is provided between the upper and lower reflective surfaces of the flexible light guide plate 702 and the LEDs.

By using such a backlight in combination with a flexible liquid crystal display panel, it becomes possible to cope with the panel configuration in which the four sides shown in FIG. 11 are flexible.

In the above example, the combination of the flexible transmissive liquid crystal display panel and the backlight has been described.
It is also possible to use a semi-transmissive liquid crystal display panel capable of both transmissive display and reflective display by providing a reflective surface on a part of the pixel electrode of the liquid crystal display panel. (Embodiment 4) A fourth embodiment will be described with reference to FIG.

The present embodiment is characterized in that a flexible light-transmitting touch panel 1003 is provided in addition to a flexible reflective liquid crystal display panel 1001 and a front light 1002 as a flexible flat lighting device. To do.

FIG. 16 shows a reflection type liquid crystal display panel 100.
1 is a diagram illustrating the arrangement of a front light 1002, a front light 1002, and a touch panel 1003.

The reflective liquid crystal display panel has a pixel electrode 110.
Reference numeral 1 is a reflective electrode, which has a structure for reflecting light incident from the upper surface.

The polarizing plate 412 has a one-sheet type polarizing plate structure which also serves as an incident polarizer and an analyzer.

The front light 1002 includes a light guide plate 1102.
The total reflection and transmission are controlled by the triangular prism shape provided on the upper part of the panel, the liquid crystal panel 1001 is illuminated from the upper part, and the reflected light forming the display image is transmitted.

By using a flexible optical material for the light guide plate 1102, it is possible to bend the sheet in the horizontal direction. The touch panel 1003 also has flexibility by using a flexible film material for the substrate 1103.

The voids provided by the rib spacer 1104 are electrically contacted by the writing pressure of the stylus pen 1105 to change the resistance distribution of the transparent conductive film (not shown) of the substrate 1003, and the normal point is that coordinates can be detected. It is similar to the touch panel. In the image display device provided with the touch panel, the stylus pen can be housed in the image display device body when not in use.

FIG. 17 shows an example in which the stylus pen 1105 is stored. Here, a housing hole 1201 is formed in the housing 103.
It is also possible to save space by making the hole in the flexible tube a storage place for the stylus pen. If necessary, the stylus pen may have an elliptical shape according to the cross-sectional shape of the flexible tube in FIG. 5 (b). (Fifth Embodiment) Next, a fifth embodiment will be described.

FIG. 18 is a schematic sectional view for explaining this embodiment. The present embodiment is characterized in that a flexible plate-shaped flexible member 101 is provided immediately below the display panel 102. The flexible material 101 is preferably a material having a small elastic force that retains its shape when the image display device is bent, and it is necessary that the shape retention force is sufficiently stronger than the bending restoring force of the display panel 102. . The material of the flexible material 101 may be a single material or a composite material in which different materials are combined. With such a structure, the radius of curvature set by the user can be maintained for a long time.

Further, this embodiment will be described in detail with reference to FIG.

The upper casing 203 is provided with a bellows 1603. The display panel 201 is arranged below this.
Here, as the display panel 203, the liquid crystal display panel described in the above embodiments can be used. Below this, the flat plate-shaped flexible material 101 is arranged. Furthermore, bellows 1
It is covered by a lower housing 103 having 603.

Here, as the flat flexible member 101, N
An i-Ti-based shape memory alloy is used.

A heater 1701 is provided on the flexible material 101. The heater 1701 may be provided on the surface of the flexible material 101 or may be embedded.

With this structure, heat is generated by energization, and it is possible to restore the curvature of the image display device to a predetermined state without applying external force.

However, although not shown here, it is necessary to take care so that the heat of the heater 1701 does not deteriorate the liquid crystal display panel 203. Needless to say, it is necessary to ensure safety so as not to heat the battery (not shown). (Sixth Embodiment) The sixth embodiment will be described with reference to FIG.

In this embodiment, an organic EL display panel 1501 having a TFT in each pixel is used as the flexible display panel 201. The upper and lower substrates 401 and 402 are the TFT formation process and the organic EL as in the above-mentioned liquid crystal display panel.
After the formation process of the layer 1502 is completed, the glass substrate 406 is polished by etching to a thickness (about 0.1 mm or less) having flexibility, and a plastic substrate 407 is attached to the composite substrate. Light emitted from the organic EL layer is extracted in the upward direction of FIG. 20 through the transparent electrode 1503.

The present embodiment is characterized in that a flexible polymer battery 1505 is sealed in a flexible material 1504 having flexibility. By adopting this structure, the flexible support member 1504 can serve as both protection of the battery and isolation from other components, and it is possible to reduce the number of components and save space.

In the present embodiment, the flexible material 1504
Uses a composite material in order to make the flexural rigidity anisotropic. This structure is enlarged and shown in FIG. 21 (a) is a plan view and FIG. 21 (b) is a sectional view.

In this embodiment, the Cu plates 1402 are arranged in a rectangular shape between the BCB substrates 1401 made of a flexible material. Further, the bending rigidity can be adjusted by changing the thickness of the Cu plate 402. Flexibility and rigidity can be optimized by reducing the thickness of the plate arranged in the direction in which bending is allowed (lateral direction in the drawing) and increasing the thickness in the orthogonal direction.

[0077]

As shown in FIG. 22, if the screen 2101 is flat, the reflected range is the angle 2103. However, if the screen can be bent to a concave surface, the reflected range is 2102. Therefore, for example, user 2
The direct incident light from the illumination 2104 above 105 is:
By adjusting the concave shape, it is possible to adjust the arrangement so that the reflection is not visually recognized.

As described above, according to the embodiment of the present invention, it becomes possible for the user to set and hold the curvature of the image display device so as to fit the hand. Further, since the support material limits the range of curvature setting, it is possible to prevent damage to the components. Furthermore, by setting and holding the curvature to the user's preference, it is possible to minimize the reflection and improve the visibility according to the usage environment. These can be adjusted without changing the effective thickness of the image display device, and the advantage of the thinness of the image display device is not diminished.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a curvature that is set and a curvature that is held.

FIG. 3 is a plan view illustrating the first embodiment.

FIG. 4 is an explanatory diagram when the image display device is viewed from the side in the first embodiment.

FIG. 5 is a diagram illustrating the function of a flexible tube.

FIG. 6 is a diagram illustrating flexibility of the first embodiment.

FIG. 7 is a cross-sectional view of a transmissive liquid crystal display panel and a sidelight type backlight.

FIG. 8 is a diagram illustrating a configuration according to a second embodiment.

FIG. 9 is a schematic diagram showing a relationship between a fixing position of a liquid crystal display panel and a backlight and a displacement strain due to bending.

FIG. 10 is a top view showing the relationship between the position of the light source and the fixed portion in the first embodiment.

FIG. 11 is a plan view illustrating a second embodiment.

FIG. 12 is a cross-sectional view illustrating a third embodiment.

FIG. 13 is a top view showing the relationship between the position of a light source and a fixed portion in the second embodiment.

FIG. 14 is a diagram for explaining the third embodiment.

FIG. 15 is a diagram illustrating a fourth embodiment.

FIG. 16 is a diagram illustrating a fourth embodiment.

FIG. 17 is a diagram for explaining the fourth embodiment.

FIG. 18 is a diagram for explaining the fifth embodiment.

FIG. 19 is a diagram for explaining the fifth embodiment.

FIG. 20 is a diagram for explaining the sixth embodiment.

FIG. 21 is a diagram illustrating a sixth embodiment.

FIG. 22 is a diagram for explaining effects of the embodiment.

FIG. 23 is a diagram illustrating a conventional technique.

[Explanation of symbols]

101 Non-flexible material 102 display panel 103 housing 104 Flexible material 302 Flexible tube 1105 stylus pen

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiko Akiyama             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F term (reference) 5C094 AA11 AA36 AA47 BA27 BA43                       DA05 DA06 FA02 FB02 HA08                       HA10

Claims (5)

[Claims] 1. A flexible display panel, a flexible casing for covering the display panel, a flexible casing, and a flexible material for integrally holding the display panel and the casing in a desired shape. An image display device comprising: 2. The flexible material is provided along a pair of sides of the display panel, and holds the display panel and the housing in a state of being bent along the sides. 1. The image display device according to 1. 3. The image display device according to claim 1, wherein the flexible material is provided along four sides of the display panel and holds the display panel and the housing in a bent state. . 4. The image display device according to claim 1, wherein the flexible member is provided along a back surface of the display panel and holds the display panel and the housing in a bent state. 5. The image display device according to claim 1, wherein the flexible material is a flexible tube.