JP2003050554A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the discontinuity of images at the fold of a folding liquid crystal display device. SOLUTION: This liquid crystal display device has a filter for refracting the light emitted from the images on both sides near the fold in such a manner that these images are viewed as the virtual images right above the fold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a technique for removing discontinuity of an image at a seam of a screen in a liquid crystal display device in which a screen is divided and made foldable. It is a thing.

[0002]

2. Description of the Related Art Conventionally, in television technology, a method of connecting a plurality of liquid crystal display panels to form one large screen is being developed (for example, Japanese Patent Laid-Open No. 7-56136).

On the other hand, in information equipment such as a personal computer (personal computer), a liquid crystal display device is being developed in which the liquid crystal display screen is foldable so that it is opened to a large screen when it is used and folded to be small when it is not used ( For example, JP-A-7-93125 and JP-A-7-16
0363, JP-A-11-119685).

Recently, portable liquid crystal display devices (PDAs, mobile phones, wristwatches, etc.) have been miniaturized, but miniaturizing the display screen to some extent or more has an upper limit of usability of the equipment.

Such a foldable liquid crystal display device 1 is
As shown in FIGS. 14 and 15, one liquid crystal display panel (panel) 2 divided into two and the other liquid crystal display panel 3 divided into two.
And a connecting portion 4 for mechanically connecting the liquid crystal display panel 2 and the liquid crystal display panel 3, and an operating portion 5 for the user.

When the apparatus having such a structure is not used, the display screen is folded small as shown in FIG. 14 and carried, and when used, the display screen is widened to widen a desired image as shown in FIG. Can be seen.

[0007]

However, as shown in FIG. 15, the conventional folding portable liquid crystal display device has a discontinuous portion of the image at the fold when it is opened. In a small-sized liquid crystal display device, the discontinuous portion of the image occupies a large proportion of the size of the entire screen, so that it is difficult for the user to see the image.

Therefore, the present invention has to be solved in a small portable foldable liquid crystal display device in which, when the display screen is opened, the display is made so that the discontinuous portion of the screen at the fold line is not recognized. Have.

[0009]

In order to solve the above problems, the liquid crystal display device according to the present invention has the following constitution.

(1) A liquid crystal display device in which a display screen is divided and foldable so that images on both sides in the vicinity of a fold are viewed as a virtual image just above the fold on each of the divided display screens. A liquid crystal display device comprising a filter for refracting light emitted from the image. (2) The liquid crystal display device according to (1), wherein the filter includes a prism and / or a lens. (3) The liquid crystal display device according to (1), wherein a large number of fine prisms are formed in a sawtooth shape on the upper surface of the filter. (4) The liquid crystal display device according to (1), wherein the filter is formed by laminating a plurality of prism plates having different refractive indexes. (5) The filter is formed by laminating a plurality of prism plates having different refractive indexes, and the upper surface of the uppermost prism plate and the lower surface of the lowermost prism plate are formed into a fine sawtooth wavefront (1 ) The liquid crystal display device according to [1].

As described above, by providing the foldable display screen with the filter, the light emitted from the images on both sides in the vicinity of the fold of the screen is refracted by the filter and goes to the direction directly above the fold. A virtual image of the images on both sides in the vicinity of the fold is formed, and if the eyes are placed there, it looks as if the seams of the images disappeared, so that the left and right images appear to be continuous.

Further, by constructing the filter with a prism or a lens, the filter function can be produced by the prism or the lens relatively easily and at low cost.

Further, since the filter has a structure in which a plurality of prism plates having different refractive indexes are laminated, the displacement amount between the image and the virtual image is increased, and the area for hiding the joint is increased accordingly.

Further, since the upper surface of the filter is formed with a large number of fine prisms in a sawtooth shape, the visibility of the virtual image is increased and is easy to see.

Further, when the filter is formed by laminating a plurality of prism plates having different refractive indexes, a fine sawtooth wave front is formed on the upper surface of the uppermost prism plate and the lower surface of the lowermost prism plate, and the lowermost prism plate is formed. The sawtooth wave shape formed on the upper part increases the displacement amount of the virtual image and can increase the area for hiding the joint.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a liquid crystal display device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of the foldable liquid crystal display device 1 according to the present invention when it is used (opened), and FIG. 2 is a partially enlarged view of FIG.

The liquid crystal display device 1 includes a liquid crystal display panel (panel) 2 which is divided into two and a liquid crystal display panel 3 which is divided into two.
And a connecting portion 4 for mechanically connecting the liquid crystal display panel 2 and the liquid crystal display panel 3, and an operation portion 5 for the user (see FIG. 1).

The liquid crystal display panel 2 has a structure in which a filter 7 formed of, for example, a prism made of acrylic material is provided on the upper surface side of a display portion 6 made of liquid crystal.
Although not shown, a large number of fine prisms are formed in a sawtooth shape on the upper surface of the filter 7, which will be described later.

The liquid crystal display panel 3 has a structure in which a filter 9 formed of, for example, a prism made of acrylic is provided on the upper surface side of a display unit 8 made of liquid crystal.
Although not shown, many fine prisms are arranged in a sawtooth shape on the upper surface of the filter 9, as will be described later.

The filters 7 and 9 are arranged symmetrically and generate an optical path 11 (see FIG. 2) in which the light rays from the display units 6 and 8 are refracted in the direction of the connecting portion 4.

The connecting portion 4 includes a liquid crystal display panel 2 and a liquid crystal display panel 3.
It has a mechanism for connecting and to be foldable. As shown in FIGS. 1 and 2, in the connecting portion 4, there is a mechanical gap between the liquid crystal display panel 2 and the liquid crystal display panel 3, and this gap becomes a discontinuous portion of the screen. The actual mechanism of the connecting portion 4 is shown in FIG.
~ It mentions later with reference to Drawing 9 and Drawing 10-Drawing 13.

Folding type liquid crystal display device 1 having the above-mentioned structure
Works as follows. As shown in FIG. 2, it is assumed that the eyes 10 of the user are directly above the connecting portion 4. LCD panel 2,
The light emitted from the images of the display units 6 and 8 of the liquid crystal display panel 3 and the filter 7 of the liquid crystal display panel 2 and the liquid crystal display panel 3 near the connecting portion 4.
Due to the presence of the filter 9, the optical path 11 refracted toward the connecting portion 4 is formed between the actual image displayed on the display portions 6 and 8 and the eye 10 as shown in FIG. Therefore, the eyes 10 see the virtual images of the images on both sides in the vicinity of the connecting portion 4. As a result, the eyes 10 can see the continuous image as shown in FIG. 3 as if there is no space that actually exists between the screens of the liquid crystal display panels 2 and 3.

The operation of the filters 7 and 9 described above will be analytically described below. FIG. 4 is an enlarged cross-sectional view of the liquid crystal display panel 2 in the vicinity of the connecting portion 4.
An air layer 12 having a minute width exists between the upper surface of the display unit 6 and the lower surface of the filter 7. The thickness of the air layer 12 is 11, the refractive index is N1 (1.0), and the thickness of the filter 7 is 12,
The refractive index is N2 (for example, 1.49 for acrylic).

On the upper surface of the filter 7, fine prisms are arranged in a sawtooth shape. The angle of inclination of the slope of this sawtooth prism with respect to the horizontal plane is θ3. In addition,
Above the upper surface of the filter 7 is the air layer 12 (refractive index N1).

The optical path 11 through which the light emitted from one point A on the surface of the display unit 6 reaches the position C of the eye 10 has a boundary surface between the lower air layer 12 and the filter 7 and a boundary surface between the filter 7 and the upper air layer 12. Refracts at two points on the surface.

Normal line 1 of light incident on the filter 7 from the point A
Assuming that the incident angle and the exit angle of 6 are θ1 and θ2, respectively, according to Snell's law, N1 · sin θ1 = N2 · sin θ2. Therefore, θ1> θ2.

The light traveling straight inside the filter 7 at the emission angle θ2 collides with the slope of the prism on the upper surface of the filter 7. Here again, according to Snell's law, the following relation holds with respect to the normal line 17. N2 · sin (θ3−θ2) = N1 · sin θ4 Here, θ4 is the emission angle of light from the filter 7 to the air layer 12, and θ4> (θ3−θ2).

Therefore, if the inclination angle θ3 of the prism is equal to the emission angle θ4 of the light, the light exiting the filter 7 advances toward the viewpoint position C, and the eye 10 is moved to the image point A.
You will see the virtual image of.

When l1 · tan θ1 = x1 and l2 · tan θ2 = x2 are set, (x1 + x2) represents the amount of displacement between the image at the point A and the virtual image seen at the point C. The larger this displacement is,
The area where the boundary between the screens of the liquid crystal display panels 2 and 3 can be hidden becomes large. The eye 10 can see a continuous whole image as if there is no boundary between both screens.

FIG. 5 shows another embodiment of the folding type liquid crystal display device according to the present invention. This embodiment is an improvement of the above embodiment in order to further increase the amount of displacement between the image and the virtual image.

The filter 7 in this embodiment has a refractive index N
2 (eg 1.5) and thickness 12 (eg 0.55 mm)
And a lower filter 7a having a refractive index N3 (N3> N2, for example 1.77) and a thickness 13 (for example, 0.5 mm). Both the upper surface of the lower filter 7a and the lower surface of the upper filter 7b are flat surfaces, and both are in close contact with each other.

On the lower surface of the lower filter 7a, a fine prism having an inclination angle θ5 with respect to the horizontal plane is formed in a sawtooth shape. Further, a sawtooth wave is formed on the upper surface of the upper filter 7b by a fine prism having an inclination angle θ8 with respect to the horizontal plane. It should be noted that θ8> θ5.

The optical path 11 connecting the point D on the display unit 6 and the position F of the eye 10 is refracted three times, and the following relational expression is established by Snell's law for each refraction. The light emitted from point D at an angle θ1 with respect to the vertical line is emitted from the air layer 12 to the lower filter 7a.
It hits the slope of the prism. With respect to the normal line 13 to this slope, N1 · sin (θ1 + θ5) = N2 · sin θ6. Here, (θ1 + θ5) is the incident angle with respect to the normal line 13, and θ6 is the outgoing angle.

The light incident on the lower filter 7a hits the boundary between the lower filter 7a and the upper filter 7b. The incident angle with respect to the normal line 14 at this boundary line is (θ6−θ5). Therefore, if the emission angle with respect to the normal line 14 is θ7,
N2 · sin (θ6−θ5) = N3 · sin θ7.

The light that has entered the upper filter 7b at the emission angle θ7 further proceeds straight inside the upper filter 7b and strikes the slope of the prism on the upper surface of the upper filter 7b. Normal to this slope 1
The incident angle for 5 is (θ8−θ7). If the emission angle with respect to the normal 15 is θ9, then N3 · sin (θ8−θ7) = N1 · sin θ9.

When θ9 = θ8, the light is at the position F of the eye 10.
Therefore, the virtual image of the point D is visually recognized by the eye 10.

Here, as shown in FIG. 5, when x1 = l1 · tan θ1, x2 = l2 · tan (θ6−θ5), and x3 = l3 · tan θ7 are expressed, (x1 + x2 + x3) corresponds to the image D and the eye 10. It is the amount of displacement from the virtual image to be seen. Since this displacement amount is larger than the displacement amounts of the above-described embodiments, it is further effective.

Next, the structure of the connecting portion 4 of the folding type liquid crystal display device according to the present invention will be described. There are various conceivable structures of the connecting portion 4, but the structures of the sliding type and simple hinge type connecting portions 4 are shown.

As shown in FIGS. 6 to 9, the liquid crystal display device having the slide type connection structure has one liquid crystal display panel (panel) 2a divided into two and the other liquid crystal display panel 3a divided into two. The liquid crystal display panel 2a and the liquid crystal display panel 3a are provided with a connecting portion 4a which can be slid and rotated, and an operating portion 5a for the user. Here, since the liquid crystal display boards 2a and 3a have the same functions as the liquid crystal display boards 2 and 3 described above, the description thereof will be omitted here.

The connecting portion 4a is provided with a rotary shaft 20 and a cam contact support shaft 21 which are formed to project from the side wall end of the liquid crystal display panel 2a. The structure is provided with a rotating portion 22 that moves and slides. The rotating portion 22 is formed in a substantially circular shape, and has a cam portion 23, a part of which is formed into a concave curved surface, and has a structure in which a long and narrow guide groove 24 is provided at the center. When the liquid crystal display panel 3a is opened by engaging the guide groove 24 with the rotating shaft 20 and sliding the cam portion 23 against the cam contact support shaft 21, the liquid crystal display panel 3a slides while opening and moves upward. , The surface of the display screen becomes flat when it is completely opened.

That is, as shown in FIG. 8, the liquid crystal display panel 3a
When is rotated in the opening direction, the guide groove 24 rotates at the same position along the rotation shaft 20, and the cam contact support shaft 21 contacts the outer periphery of the rotation portion 22. Then, the rotary shaft 20
Since the display screen of the liquid crystal display panel 2a is rotated around the center, the display screen of the liquid crystal display panel 2a opens in a position farther than the display screen of the liquid crystal display panel 3a.

Next, as shown in FIG. 9, when the liquid crystal display panel 3a is completely opened, the guide groove 24 engaged with the rotary shaft 20 is in the longitudinal end direction, that is, the liquid crystal display panel 3a is directed upward. P1
When it moves to, the cam portion 23 comes into contact with the cam abutment shaft 21, so that it is guided along the concave curved surface of the cam portion 23, the liquid crystal display panel 3a approaches the liquid crystal display panel 2a side, and the display surface of the display portion is When they are flush, the faces are connected and the open state is complete. In this way, even when the display screen is divided, it is possible to minimize the gap between the connection parts when the display screen is opened. If this structure is provided with the prism lens (filter) described above, the connection can be reduced. You can see the image without any parts.

Next, regarding the structure of the hinge type connecting portion,
This will be described with reference to FIGS. A liquid crystal display device having a hinge-type connecting portion has one liquid crystal display panel (panel) 2b divided into two and the other liquid crystal display panel 3b divided into two.
The liquid crystal display panel 2b and the liquid crystal display panel 3b can be rotated together with a connecting portion 4b and an operating portion 5b for the user.

The connecting portion 4b has a so-called hinge structure, and is formed so that the connecting portion is located at the upper position of the seam of the panel, and is located at the end of the liquid crystal display panel 2b and at the upper position of the panel. The first engaging portion 25 is provided at the end of the liquid crystal display panel 3b so that the second engaging portion 25 is located at the upper position of the panel.
It has a structure in which the engaging portion 26 is provided. By rotatably assembling the second engaging portion 26 to the first engaging portion 25, the liquid crystal display board 3b has a rotatable structure with respect to the liquid crystal display board 2b. As shown in FIG. 13, the ends are in contact with each other around the connecting portion 4b, and the surface of the panel at that time is flush.

In this way, the connecting portion 4b of the hinge structure is formed.
In this case, the first and second engaging portions 25 and 26 are thickened, but the structure is simple and the area of the joint portion of the panel can be reduced.

[0047]

As described above, the foldable liquid crystal display device according to the present invention is a liquid crystal display device in which the screen is divided and foldable, and images on both sides in the vicinity of the fold are directly above the fold. Since the virtual image of the image in the vicinity of the fold is viewed by providing the filter that refracts the light of the image so that it is viewed as a virtual image, the discontinuous portion of the actual image can be viewed as if it were continuous. Therefore, there is an effect that usability can be improved without impeding the further downsizing of PDAs, mobile phones, wrist watches and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a foldable liquid crystal display device according to the present invention.

FIG. 2 is an explanatory diagram showing an operation principle of the embodiment.

FIG. 3 is an explanatory diagram of a display operation of the same embodiment.

FIG. 4 is an explanatory diagram showing an example of a filter of the folding type liquid crystal display device.

FIG. 5 is an explanatory diagram showing another embodiment of the filter.

FIG. 6 is a plan view schematically showing a liquid crystal display device having a slide type connecting portion.

FIG. 7 is a side view schematically showing a liquid crystal display device having the slide type connection part shown in FIG.

FIG. 8 is an explanatory diagram showing an enlarged view of the slide-type connecting portion shown in FIG.

FIG. 9 is an explanatory diagram showing an enlarged view of the slide-type connecting portion shown in FIG. 6.

FIG. 10 is a plan view schematically showing a liquid crystal display device having a hinge type connecting portion.

11 is a side view schematically showing a liquid crystal display device having the hinge-type connecting portion shown in FIG.

FIG. 12 is an enlarged view of the hinge-type connecting portion shown in FIG.

FIG. 13 is an enlarged view of the hinge type connecting portion shown in FIG.

FIG. 14 is an overall configuration diagram schematically showing a conventional liquid crystal display device.

15 is an overall configuration diagram schematically showing a state in which the liquid crystal display device in FIG. 14 is opened.

[Explanation of symbols]

1: Foldable liquid crystal display device, 2, 2a, 2b: Liquid crystal display panel, 3, 3a, 3b: Liquid crystal display panel 4, 4a, 4b:
Connection parts 5, 5a, 5b: operation part, 6, 8: display part,
7, 9: Filter, 10: Eye, 11: Optical path, 12: Air layer, 13-17: Normal, 20: Rotating shaft, 21: Cam abutment shaft, 22: Rotating shaft, 23: Cam part, 24: guide groove,
25: 1st engaging part, 26: 2nd engaging part.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H089 HA33 HA40 KA16 QA11 TA12                       TA16                 2H091 FA21X FA26X LA11 LA16                       LA30                 5C094 AA01 AA14 BA43 CA19 DA01                       DA08 ED01                 5G435 AA01 BB12 CC09 EE16 EE17                       FF02 FF08 GG03 GG11 LL07                       LL08 LL10

Claims (5)

[Claims] 1. A liquid crystal display device in which a display screen is divided and foldable so that images on both sides in the vicinity of a fold are viewed as a virtual image just above the fold on each of the divided display screens. A liquid crystal display device comprising a filter for refracting light emitted from the image. 2. The liquid crystal display device according to claim 1, wherein the filter includes a prism and / or a lens. 3. The liquid crystal display device according to claim 1, wherein a plurality of fine prisms are formed in a sawtooth shape on the upper surface of the filter. 4. The liquid crystal display device according to claim 1, wherein the filter is formed by laminating a plurality of prism plates having different refractive indexes. 5. The filter is formed by laminating a plurality of prism plates having different refractive indexes, and the upper surface of the uppermost prism plate and the lower surface of the lowermost prism plate are formed into a fine sawtooth wavefront. The liquid crystal display device according to claim 1.