JP3256531B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an office automation (OA) such as a personal computer, a word processor, and an OHP (overhead projector).
The present invention relates to a liquid crystal display device suitably used as a display device for devices, for public use, for electronic watches, and for on-vehicle devices. More specifically, the device has a sealing member and a spacing member exhibiting optical characteristics substantially equivalent to a liquid crystal layer. The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view of a general TN (twisted nematic) liquid crystal display device 21, and FIG. 9 is a plan view of a TN liquid crystal cell 23 shown in FIG. The TN liquid crystal display device 21 includes a TN liquid crystal cell 23 and a TN liquid crystal cell 2.
3 and a pair of polarizing plates 22 and 24 arranged so as to sandwich the same. The TN liquid crystal cell 23 includes a pair of substrate members 23a and 23b, a sealing member 23d for bonding the pair of substrate members 23a and 23b at predetermined intervals, and a liquid crystal interposed between the pair of substrate members 23a and 23b. And a layer 23c. The substrate members 23a and 23b have electrodes and alignment films (not shown) on the surface on the liquid crystal layer 23c side.

[0003] The liquid crystal display device 21 constructed as described above
In Japanese Patent Application Laid-Open No. 55-77
722, JP-A-60-181730, JP-A-62-29
As shown in 5029, an epoxy resin or a photo-curable acrylic resin is used.

[0004]

In the liquid crystal display device 21 as described above, light from the lower side on the plane of FIG. 8 is converted into linearly polarized light by transmitting through the polarizing plate 24.
The linearly polarized light is twisted 90 ° in the liquid crystal layer 23c due to the optical rotation due to the twist of the molecule, and is transmitted in the same direction as the polarization axis of the polarizing plate 22. However, the sealing member 23 realized by an epoxy resin or an acrylic resin
In the part d, since the molecules of the sealing member 23d are isotropic and do not show optical activity, the linearly polarized light is not subjected to the twisting action and has a direction different from the polarization axis of the polarizing plate 22 by 90 °. Remains. Therefore, light does not pass through the portion of the sealing member 23d, and the sealing member 23d is visible. Therefore, if the sealing member 23d is visible, the sealing member 23d
It is necessary to cover and hide d with a cover member so that it cannot be seen. For this reason, the sealing member 23d corresponds to the cover member.
A certain distance must be ensured between this part and the display part which is the active area, and the display part is considerably smaller than the size of the liquid crystal display device. For example, in FIG. 9, a distance of 6.0 mm is provided between the portion of the sealing member 23d indicated by oblique lines and the display portion 23e indicated by two-dot chain lines to deal with the cover member. Further, there is a problem that the sealing member cannot be arranged inside the space to be filled with the liquid crystal, and the shape of the liquid crystal display device is restricted.

An object of the present invention is to provide a liquid crystal display device in which a sealing member and a spacing member are not visible in order to solve the above problems.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a pair of substrate members are disposed on a surface near a peripheral portion of opposing surfaces of the pair of substrate members, and the pair of substrate members are bonded at a predetermined interval. In a liquid crystal display device including a sealing member , and a liquid crystal layer sealed in a space surrounded by the pair of substrate members and the sealing member, the sealing member includes liquid crystal.
The space holding member is provided with liquid crystal added therein and having optical characteristics substantially equivalent to the liquid crystal layer in a space to be filled with the liquid crystal layer. A liquid crystal display device characterized by the above-mentioned.

According to the present invention, in the liquid crystal display device, a space holding member to which liquid crystal is added and which has optical characteristics substantially equivalent to those of the liquid crystal layer is provided inside a space to be filled with the liquid crystal layer. The spacing member has optical properties such as optical rotation, birefringence, dichroism, and polarization that are substantially equivalent to those of the liquid crystal layer. Therefore, light transmitted through the liquid crystal display device exhibits almost the same behavior between the portion of the spacing member and the portion of the liquid crystal layer. (Becomes invisible), so that the spacing member can be arranged at the center of the liquid crystal layer, thereby making it possible to produce a liquid crystal display device having a uniform thickness of the liquid crystal layer.

[0008]

FIG. 1 is a sectional view of a TN liquid crystal display device 1 according to one embodiment of the present invention, and FIG. 2 is a plan view of a TN liquid crystal cell 3 shown in FIG. TN liquid crystal display device 1
Is configured to include a TN liquid crystal cell 3 and a pair of polarizing plates 2 and 4 arranged so as to sandwich the TN liquid crystal cell 3. TN
The liquid crystal cell 3 includes a pair of substrate members 3a and 3b, a sealing member 3d for bonding the pair of substrate members 3a and 3b at predetermined intervals, and a liquid crystal layer interposed between the pair of substrate members 3a and 3b. 3c.

The substrate members 3a and 3b are made of a light-transmitting substrate made of glass, plastic, or the like, a predetermined electrode pattern formed on one surface of the light-transmitting substrate, and an alignment film formed covering the electrode pattern. And are arranged so that the alignment films face each other. The electrode pattern may be any pattern such as a segment type, a simple matrix type, and an active matrix type.

As a liquid crystal material constituting the liquid crystal layer 3c,
A liquid crystal material having a refractive index anisotropy (Δn) of 0.105 and a molecular twist angle (φ) of 90 ° is used. Sealing member 3d
Is used as a material having the same Δn or φ as the liquid crystal material forming the liquid crystal layer 3c.

The sealing member 3d is manufactured as follows. First, several optically active polymer materials having a glass phase below the nematic phase are mixed so that Δn = 0.105, and a chiral molecular structure is formed so as to have the same pitch as the liquid crystal material to be encapsulated. A certain cholesteric liquid crystal is added. This is printed in an arbitrary shape on a film that has been subjected to an orientation (rubbing) process, and an orientation process is performed so that the twist angle is 90 °. Then, the thing fixed by cooling is peeled off from the film. The sealing member 3d manufactured as described above is transferred to the surface of the substrate member using an acrylic optical adhesive, and the pair of substrate members 3a and 3b are bonded by pressing with a certain pressure.

The polymer material may be, for example, a linear liquid crystal polymer such as an optically active polyester, polyimide, or polycarbonate which is in a glassy state below the liquid crystal transition point, or a side chain such as polyacrylate, polymalonate or polysiloxane. A liquid crystal polymer is used. The acrylic optical adhesive is applied to the surface of the sealing member by a flat nozzle, and has a thickness of about 50 nm. Alternatively, the material itself of the sealing member can be provided with adhesiveness without using an adhesive.

FIG. 3 is a plan view showing the positional relationship between the components of the TN liquid crystal display device 1. An arrow 5 is a liquid crystal molecule orientation axis of one substrate member 3a constituting the TN liquid crystal cell 3, an arrow 6 is a liquid crystal molecule orientation axis of the other substrate member 3b constituting the TN liquid crystal cell 3, and an arrow 7 is a polarization axis of the one polarizing plate 2. , Arrow 8 indicates the polarization axis of the other polarizing plate 4, arrow 9 indicates the molecular orientation axis of the sealing member of the substrate member 3a constituting the TN liquid crystal cell 3, and arrow 10
Represents the orientation axis of the sealing member molecule of the other substrate member 3b constituting the TN liquid crystal cell 3, and the angle φ represents the twist angle (twist angle) of the liquid crystal molecule and the sealing member molecule.

In this embodiment, the liquid crystal molecule orientation axis 5 and the sealing member molecule orientation axis 9 of the one substrate member 3a are parallel to the polarization axis 7 of the polarizing plate 2 and the liquid crystal molecule orientation axis of the other substrate member 3b. 6 and the sealing member molecule orientation axis 10 are parallel to the polarization axis 8 of the polarizing plate 4, and φ of the liquid crystal molecules and the sealing member molecules is set to 90 °, so that the TN liquid crystal display in the normally white mode is performed. The device was created.

The above embodiment is a case of a normally white mode in which light is transmitted when no voltage is applied, but a case of a normally black mode in which light is not transmitted when no voltage is applied. The same applies.

According to this embodiment, the light from the lower side on the paper of FIG. 1 becomes linearly polarized light by passing through the other polarizer 4 in the liquid crystal layer 3c, and the optical rotation due to the twist of the molecules of the liquid crystal layer 3c. Twisted by 90 ° for the sake of clarity, while being in the same direction as the polarization axis 7 of the polarizer 2 and transmitting. Also in the sealing member 3d, light from the lower side on the plane of FIG. 1 is converted into linearly polarized light by passing through the polarizing plate 4, and 90% due to optical rotation due to twisting of molecules of the sealing member 3d. °, on the other hand, is in the same direction as the polarization axis 7 of the polarizing plate 2 and is transmitted. Therefore, since light is transmitted through the liquid crystal layer 3c and the sealing member 3d in the same manner, it becomes impossible to distinguish the liquid crystal layer 3c from the sealing member 3d in appearance. It can be extended to the vicinity of the sealing member 3d. For example, as shown in FIG. 2, the distance between the display portion 3e indicated by the two-dot chain line and the sealing member 3d indicated by the diagonal line can be made only about 1.5 to 2.0 mm.

FIG. 4 is a plan view of a TN liquid crystal display device 11 according to another embodiment of the present invention, and FIG.
FIG. 2 is a cross-sectional view of the liquid crystal display device 11. In the plan view shown in FIG. 4, the sealing member 13d functioning as a spacing member is shown with diagonal lines. In the above-described embodiment, the sealing member 3d is disposed on the surface near the peripheral edge of the liquid crystal layer 3c to form the rectangular liquid crystal display device 1. In this embodiment, however, the gap between the opposing surfaces of the circular substrate members 13a and 13b is provided. Sealing member 13
The ring-shaped liquid crystal display device 11 was obtained by arranging d at the periphery and the center of the liquid crystal layer 13c. This liquid crystal display device 11
Is used, for example, on a dial of a timepiece (watch, etc.) using hands 12a (short hands) and 12b (long hands) attached to a shaft 12c, as shown, and displays various information.

According to the present embodiment, since the sealing member 13d is not visible, even if the sealing member 13d is disposed inside the space to be filled with the liquid crystal, there is no uncomfortable feeling, and the sealing member 13d
There is no need to hide the part. Further, since the sealing member 13d exists inside the space to be filled with the liquid crystal, the thickness of the liquid crystal becomes uniform. Therefore, a liquid crystal display device having an arbitrary shape and a uniform liquid crystal thickness can be manufactured.

FIG. 6 is a plan view of a TN liquid crystal display device 14 according to still another embodiment of the present invention. In this embodiment,
In addition to the sealing member 16 shown by oblique lines, a pair of substrate members are attached at a predetermined interval in the vicinity of the periphery of the substrate member,
A liquid crystal display device 1 using one or more (here, three at the left, right and center) spaces inside the space to be filled with the liquid crystal as sealing members 15 indicated by two-dot chain lines as spacing members.
And 4. According to the present embodiment, it is possible to produce a liquid crystal display device having a uniform thickness of the liquid crystal layer by using the sealing member 15 functioning as a spacing member.

FIG. 7 is a plan view of a TN liquid crystal display device 17 according to still another embodiment of the present invention. In this embodiment, the liquid crystal display device 17 is configured such that the sealing member 18 indicated by oblique lines is arranged so as to divide the liquid crystal layer into a plurality of portions other than the vicinity of the periphery of the substrate member. According to this embodiment, a plurality of (here, four) display portions 19a, 19b, 19c, 1
It is possible to create a liquid crystal display device that is used by being divided into 9d.

In the above embodiment, the combination of the TN liquid crystal material and the sealing member made of a liquid crystalline polymer material has been described. However, the material used is not limited to this.
Combination of STN (super twisted nematic) liquid crystal material and optically and birefringent sealing member, combination of polymer dispersed liquid crystal material and light scattering sealing member, GH (guest host) Needless to say, a combination of a liquid crystal material and a sealing member in which dichroic dyes are oriented in a specific direction may be used.

[0022]

As described above, according to the present invention, the thickness of the liquid crystal layer of the liquid crystal display device can be made uniform by disposing the spacing member at the center of the liquid crystal layer.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display device 1 according to one embodiment of the present invention.

FIG. 2 is a plan view of the liquid crystal cell 3 shown in FIG.

FIG. 3 is a plan view showing a positional relationship between components of the liquid crystal display device 1 shown in FIG.

FIG. 4 is a plan view of a liquid crystal display device 11 according to another embodiment of the present invention.

5 is a sectional view of the liquid crystal display device 11 shown in FIG.

FIG. 6 is a plan view of a liquid crystal display device 14 according to still another embodiment of the present invention.

FIG. 7 is a plan view of a liquid crystal display device 17 according to still another embodiment of the present invention.

FIG. 8 is a cross-sectional view of a liquid crystal display device 21 which is a typical conventional example.

9 is a plan view of the liquid crystal cell 23 shown in FIG.

[Description of Signs] 1,11,14,17 Liquid crystal display device 2,4 Polarizer 3 Liquid crystal cell 3a, 3b, 13a, 13b Substrate member 3c, 13c Liquid crystal layer 3d, 13d, 15,16,18 Sealing member 3e , 19a, 19b, 19c, 19d Display portion 5, 6 Liquid crystal molecular alignment axis 7, 8 Polarizing plate polarization axis 9, 10 Sealing member molecular alignment axis 12a, 12b Needle 12c axis

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1339 G02F 1/1347 G02F 1/1333 G09F 9/30

Claims (1)

(57) [Claims] 1. A pair of substrate members, a sealing member arranged on a surface near a peripheral edge of opposing surfaces of the pair of substrate members, and bonding the pair of substrate members at a predetermined interval; In a liquid crystal display device including a liquid crystal layer sealed in a space surrounded by a substrate member and the sealing member, the sealing member is substantially equal to the liquid crystal layer by adding liquid crystal.
A liquid crystal display , wherein a space holding member having liquid crystal added and having optical characteristics substantially equivalent to the liquid crystal layer is provided inside a space to be filled with the liquid crystal layer, apparatus.