JP2001305525A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device where the display picture is simultaneously visible from both surfaces of the single liquid crystal panel. SOLUTION: The liquid crystal display device is provided with a liquid crystal panel 10 comprising a first substrate 4 with a first electrode 2, a second substrate 5 with a second electrode 3 and a liquid crystal layer 1 arranged between the first substrate 4 and the second substrate 5 and a pair of polarizing plates 6, 7 arranged on both surfaces of the liquid crystal panel 10. Furthermore, the device is provided with a first body 8 capable of reflecting or emitting light and arranged on a part of the polarizing plate 6 arranged on the side of the first substrate 4 and a second body 9 capable of reflecting or emitting light and arranged on a position not confronted with the first body 8 on the polarizing plate 7 arranged on the side of the second substrate 5.

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 liquid crystal display device capable of simultaneously displaying images on both surfaces thereof.

[0002]

2. Description of the Related Art Conventional liquid crystal display devices include a reflection type, a transflective type and a transmissive type. One of the surfaces of a liquid crystal panel is a reflection plate or a semi-transmission plate for reflecting external light, or light from one surface. By providing a backlight that emits light, the structure can be viewed from the other surface.

[0003] Today, there is a demand for electronic devices having a liquid crystal display element to be reduced in size and thickness. Considering the case of carrying an electronic device, a display unit necessary for inputting or processing information, and inputting and processing of information for the purpose of merely displaying information are not so focused. There is also a need for an electronic device having two screens, one with no display screen. As such an example,
There is a mobile phone provided with two separate liquid crystal display elements described in JP-A-6-37697.

In the liquid crystal display devices described in JP-A-11-231303 and JP-A-11-287987, one front panel and one rear panel are viewed using one liquid crystal panel. The liquid crystal is driven by selecting one of them.

[0005]

However, when a plurality of liquid crystal panels are provided in an electronic device, the size of the device is increased, and a plurality of driving circuits for driving the liquid crystal panel are required. As a result, there is a problem that the configuration of the device becomes complicated and power consumption and cost increase.

[0006] When one liquid crystal panel is provided in a device and one of the two surfaces is displayed, if an image is displayed on one surface, no image is displayed on the other surface or only an inverted image is obtained. Therefore, both sides could not be used at the same time. Furthermore, in order to make an image visible from both sides of one liquid crystal panel, the configuration of the polarizing plate must be complicated and the polarization direction of light must be adjusted, so that the size of the liquid crystal display element increases. When the two liquid crystal panels are overlapped and driven separately, a liquid crystal display element that can be viewed from both sides can be provided at the same time. However, the thickness of the liquid crystal display element increases, so that the size of the electronic device is reduced. It is not suitable for the purpose of reducing the size and thickness, and furthermore, two circuits for driving the liquid crystal are required, so that the power consumed by the liquid crystal display element increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device which allows a display screen to be viewed simultaneously from both sides of one liquid crystal panel.

[0008]

A first feature of a liquid crystal display device according to the present invention for achieving the above object is to form a first electrode as described in claim 1 of the claims. A liquid crystal panel comprising: a first substrate having a second electrode having a second electrode; and a liquid crystal layer disposed between the first substrate and the second substrate; and a pair of liquid crystal panels provided on both surfaces of the liquid crystal panel. A liquid crystal display element comprising: a first polarizer provided on the first substrate side.
A first object capable of reflecting or emitting light partially provided on a surface opposite to a surface on the substrate side, and a second substrate side of the polarizing plate provided on the second substrate side; And a second object that is provided at a position opposite to the first object and that is opposite to the first object and that can reflect or emit light.

[0009] The second feature of the present invention is that the first substrate having the first electrode, the second substrate having the second electrode, and the first substrate are provided as described in claim 2 of the claims. A liquid crystal display device comprising a liquid crystal panel including a liquid crystal layer disposed between the second substrate and a pair of polarizing plates provided on both surfaces of the liquid crystal panel, wherein the first electrode is Partially made of a first object capable of reflecting light, the position of the second electrode that does not face the first object is a point made of a second object capable of reflecting light.

The third feature configuration further includes a drive circuit for driving a liquid crystal, in addition to the first or second feature, as described in claim 3 of the claims. A first display direction in which the display of the liquid crystal in the first display area defined by the first object can be correctly viewed, and a first display direction in which the display of the liquid crystal in the second display area defined by the second object can be correctly viewed. The two display directions are in a point that the display directions are reversed left and right as viewed from the first display area.

The fourth feature configuration further includes a drive circuit for driving the liquid crystal, in addition to the first or second feature, as described in claim 4 of the claims. A first display direction in which the display of the liquid crystal in the first display area defined by the first object can be correctly viewed, and a first display direction in which the display of the liquid crystal in the second display area defined by the second object can be correctly viewed. The two display directions are points that are upside down as viewed from the first display area.

The operation and effect will be described below. According to the first characteristic configuration of the liquid crystal display device of the present invention, an object capable of reflecting or emitting light is partially provided on one surface of the liquid crystal panel, and is provided on the other surface at a position not opposed to the object. An object capable of reflecting or emitting light is provided. With the above configuration, the display screen can be viewed from one surface of the liquid crystal display element and simultaneously from the other surface. The display can be viewed simultaneously on both sides using one liquid crystal panel, and the thickness of the electronic device having the liquid crystal display element of the present invention can be made equal to the thickness of the conventional single-side display thin device. Further, since one liquid crystal panel is used, only one drive IC for driving liquid crystal is required, which is advantageous in terms of reduction of power consumption, simplification of a drive circuit, reduction of cost, and the like. .

In addition, when the liquid crystal display device of the present invention is mounted on an electronic device having a lid or a folding type, necessary information is displayed even when the electronic device is in a state where the lid is closed or folded. Since one of the liquid crystal display surfaces can always be viewed, there is no need to open the lid to view information or to change the state from a folded state to an extended state. Therefore, if the radio wave condition, remaining battery power, time display, memo, and the like of the electronic device are always displayed on one of the liquid crystal screens, the above information can be obtained even when the electronic device is not in use.

According to the second aspect, in addition to the functions and effects of the first aspect, the number of components in the thickness direction of the liquid crystal display element is reduced, so that the thickness of the liquid crystal display element can be further reduced. Can be planned. Therefore, when the present liquid crystal display element is provided in an electronic device, the size of the device can be further reduced.

According to the third and fourth features, the liquid crystal display element further includes a driving circuit for driving the liquid crystal, and displays the liquid crystal in the first display area defined by the first object. The first display direction in which the display can be correctly viewed and the second display direction in which the display of the liquid crystal in the second display area defined by the second object can be correctly viewed are left and right or up and down when viewed from the first display area. When the electronic device on which the liquid crystal display element of the present invention is arranged is closed or folded right and left or up and down (front and back), the display direction for a viewer of the display screen is before and after folding. This is convenient because it does not change.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device according to the present invention will be described with reference to FIG. The liquid crystal display element 100 includes a first substrate 4 having a first electrode 2 and a second substrate 4 having a second electrode 3.
The liquid crystal panel 10 includes a substrate 5, a liquid crystal layer 1 disposed between the first substrate 4 and the second substrate 5, and a pair of polarizing plates 6 and 7 provided on both surfaces of the liquid crystal panel 10. Of the polarizing plate 6 provided on the first substrate 4 side.
A first object 8 capable of reflecting or emitting light, partially provided on a surface opposite to the surface on the side, and a second substrate 5 side of a polarizing plate 7 provided on the second substrate 5 side And a second object 9 which is provided on a surface opposite to the surface and which is not opposed to the first object 8 and which can reflect or emit light. Here, the second object 9 may be disposed over the entire surface at a position that does not face the first object 8, or may be partially disposed. The second object 9 is the first
When the object 8 is partially arranged at a position where the object 8 does not face, another arbitrary object can be arranged at the remaining position.

Here, as the substrate 4 or 5 having the electrodes 2 or 3, a glass substrate or the like on which a transparent conductive film is deposited is generally used. Objects 8 and 9 are common reflectors,
It is an object capable of reflecting or emitting light, such as a translucent plate or a backlight, and these may be used in combination. Further, the combination of the liquid crystal layer 1 and the polarizing plates 6 and 7 may be arbitrarily set according to the display mode of the liquid crystal and the driving method of the liquid crystal.

In the liquid crystal display device 100 according to the present invention illustrated in FIG. 1, when the objects 8 and 9 are reflectors or semi-transmissive plates, a first display area 11 (hereinafter referred to as an area defined by the area of the first object 8). , "The main display unit 11") or light incident on the second display region 12 (hereinafter, "the sub display unit 12") defined by the region of the second object 9 has a predetermined polarization function. Polarizing plate 7 or 6,
Glass substrate 5 or 4, light transmissive electrode 3 or 2, liquid crystal layer 1, electrode 2 or 3, polarizing plate 4 or 5, polarizing plate 6
Or 7 sequentially passes to the object 8 or 9 made of a reflecting plate or a semi-transmitting plate. The light reflected by the object 8 or 9 follows the reverse path to the above, and the liquid crystal display element 1
Go outside 00 and see the eyes of people. At this time, light is modulated by applying an electric field to the liquid crystal layer 1, and a gray scale between white, halftone, and black is displayed. Here, another optical element such as a retardation plate may be arranged in the optical path of the liquid crystal display element 100 in order to change the polarization state and phase of the light. If the liquid crystal display element 100 has a color filter, color display is also possible.

When the objects 8 and 9 are backlights, the light emitted from the object 8 or 9 for each of the main display unit 11 and the sub display unit 12 is polarized by a polarizing plate 6 or 7 having a predetermined polarization function. , The glass substrate 4 or 5, the light-transmissive electrode 2 or 3, the liquid crystal layer 1, the electrode 3 or 2, the glass substrate 5 or 4, and the polarizing plate 7 or 6, and sequentially out of the liquid crystal display element 100. And get into the eyes of people. At this time, light is modulated by applying an electric field to the liquid crystal layer 1, and a gray scale between white, halftone, and black is displayed. Here, another optical element such as a retardation plate may be arranged in the optical path of the liquid crystal display element 100 in order to change the polarization state and phase of the light. If the liquid crystal display element 100 has a color filter, color display is also possible.

The liquid crystal display element 200 shown in FIG. 2 has a first substrate 4 having a first electrode 2, a second substrate 5 having a second electrode 3, and disposed between the first substrate 4 and the second substrate 5. Liquid crystal panel 10 comprising a liquid crystal layer 1 formed by
And a pair of polarizing plates 6 and 7 provided on both surfaces of the first electrode 2, the first electrode 2 partially includes a first object 8 capable of reflecting light, and a first object of the second electrode 3. A position that does not face 8 is formed of a second object 9 that can reflect light. Here, the second object 9 is the first object 9
It may be arranged over the entire surface not facing the object 8 or may be partially arranged. When the second object 9 is partially arranged at a position where the first object 8 does not oppose, another arbitrary object can be arranged at the remaining position.

In the liquid crystal display device 100 shown in FIG. 1, a reflecting plate or a semi-transmissive plate is provided outside the liquid crystal panel 10, but in the liquid crystal display device 200 shown in FIG. 3 partially comprises a conductive object 8 or 9 respectively, which can reflect light. With such a configuration, the electrodes 2 and 3 which function as a light-transmitting electrode and partially function as a reflecting plate or a semi-transmitting plate are provided.

As described above, the liquid crystal display device according to the present invention has the main display section 11 and the sub display section 12, and the liquid crystal screen can be simultaneously viewed from both sides by using one liquid crystal panel 10. It has a configuration. Next, an example in which an image is displayed on the main display unit 11 and the sub display unit 12 by driving the liquid crystal display element according to the present invention will be described with reference to FIGS.

FIG. 3A shows a state in which a driving circuit 13 having a driving IC 14 is connected to the liquid crystal display element according to the present invention, and the display directions of the main display unit 11 and the sub display unit 12 are reversed left and right. FIG. 3B is a diagram showing a state where the display direction is inverted upside down. The display of the sub-display unit 12 when viewed from the main display unit 11 and the display of the main display unit 11 when viewed from the sub-display unit 12 side are blocked by a reflector, a semi-transmissive plate, or a backlight. Although it is invisible or difficult to see, FIGS. 3A and 3B illustrate what it looks like virtually.

As shown in FIG. 3 (a), when viewed from the main display section 11, characters are normally displayed on the main display section 11, but reversed characters are displayed on the sub-display section 12. This is because, on the assumption that the lid or the like of the electronic device on which the liquid crystal display element is arranged is closed to the left and right, the program for displaying the information is executed.
When it is assumed that the electronic device is closed up and down (front and back), the main display unit 11 and the inverted characters may be displayed on the sub display unit 12 as shown in FIG.
Therefore, regardless of the direction in which the electronic device on which the liquid crystal display element is disposed is closed, the display screen of each display unit can be directed in a correct direction for a viewer.

Further, a driving IC having a partial display function
Is used, only the main display unit 11 is displayed, or only the sub display unit 12 is displayed.
It is easy to switch the display between the main display unit 11 and the sub display unit 12 individually. As described above, if a function of individually switching the display is provided, only one of the display units can be displayed, and the power consumption of an electronic device using the liquid crystal display element according to the present invention can be reduced. it can. Here, as a driving method of the liquid crystal, a general method such as an active matrix method or a passive matrix method can be used.

The liquid crystal display device 100 or 2 according to the present invention
An example of an electronic device 300 provided with 00 will be described with reference to FIG. The electronic device 300 includes the liquid crystal display element 100 or 2
00 is provided with a display device section 13 in which 00 is arranged and an input device section 14 for inputting information. In a normal use state, the input device unit 14 is operated while looking at the main display unit 11. The sub display unit 12 may display information such as radio wave condition, remaining battery power, time display, and memo. If such information is displayed on the sub-display unit 12, the sub-display unit 12 is visible even when the display device unit 13 is closed so as to protect the main display unit 11. , The information such as the remaining battery power, the time display, and the memo can always be confirmed on the sub display unit 12. Further, even if the display of the main display unit 11 is turned off, necessary information can be always obtained by setting so that power is supplied to the sub display unit 12 by the power of the battery. The electronic device 300 is not limited to the structure exemplarily shown in FIG. 4, and other examples include a notebook computer, a portable information device such as an electronic organizer, a remote controller, and the like.

<Another Embodiment> A case has been described where both the first object 8 and the second object 9 are reflectors or transflectors, or both the first object 8 and the second object 9 are backlights. , The first object 8 may be a reflector or a transflector, and the second object 9 may be a backlight,
Or, any combination such as the reverse may be used.

Further, the liquid crystal layer 1 does not need to be uniformly oriented over the entire surface of the liquid crystal panel 10, and portions of the liquid crystal layer 1 corresponding to the main display section 11 and the sub display section 12 are:
They may be in different alignment states. Similarly, the polarizing plates 6 and 7 may have partially different polarizing functions according to the alignment state of the liquid crystal.

If the main display section 11 and the sub-display section are surrounded by a material having a light-blocking function such as a black matrix, light does not leak from each other even if the reflectors or backlights are arranged opposite to each other. Clear indications can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a liquid crystal display device according to the present invention.

FIGS. 3A and 3B show a case where the display on the main display unit and the sub display unit of the liquid crystal display element according to the present invention is (a) horizontally inverted;
(B) is a diagram showing a case where the display is turned upside down.

FIG. 4 is a diagram showing an example of a device provided with the liquid crystal display element according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal layer 2 first electrode 3 second electrode 4 first substrate 5 second substrate 6 polarizing plate 7 polarizing plate 8 first object 9 second object 10 liquid crystal panel 11 main display unit (first display area) 12 sub display unit (Second display area) 13 Driving circuit 14 Driving IC 15 Display unit 16 Input unit 100, 200 Liquid crystal display element 300 Electronic equipment

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H091 FA02Y FA08X FA08Z FA11X FA14X FA14Z FA41Z GA11 LA11 5C094 AA15 AA48 AA56 BA43 DA08 DA12 DA13 EA04 EA05 EA06 EB02 ED11 ED14 ED20 FA01 FA02

Claims (4)

[Claims] A liquid crystal panel comprising: a first substrate having a first electrode; a second substrate having a second electrode; and a liquid crystal layer disposed between the first substrate and the second substrate. What is claimed is: 1. A liquid crystal display device comprising: a pair of polarizing plates provided on both surfaces of a liquid crystal panel, on a surface of the polarizing plate provided on the first substrate side opposite to a surface on the first substrate side. A first object capable of reflecting or emitting light, partially provided on the second substrate side of the polarizing plate provided on the second substrate side, A liquid crystal display device further comprising a second object provided at a position not facing the first object and capable of reflecting or emitting light. 2. A liquid crystal panel comprising: a first substrate having a first electrode; a second substrate having a second electrode; and a liquid crystal layer disposed between the first substrate and the second substrate. A liquid crystal display device comprising: a pair of polarizing plates provided on both sides of a liquid crystal panel, wherein the first electrode is partially made of a first object capable of reflecting light, and the second electrode The liquid crystal display device according to claim 1, wherein the position not facing the first object is a second object capable of reflecting light. 3. A driving circuit for driving the liquid crystal, wherein the driving circuit is provided with a first display direction in which a display of the liquid crystal in a first display area defined by the first object can be correctly viewed, and the driving circuit is defined by the second object. The liquid crystal display element according to claim 1, wherein the second display direction in which the display of the liquid crystal in the second display area is correctly viewed is reversed left and right as viewed from the first display area. 4. A driving circuit for driving a liquid crystal, wherein the driving circuit is provided with a first display direction in which a display of the liquid crystal in a first display area defined by the first object can be correctly viewed and the second object defines the display direction. 3. The liquid crystal display device according to claim 1, wherein the second display direction in which the displayed liquid crystal in the second display area can be correctly viewed is vertically inverted when viewed from the first display area. 4.