JP2015138125A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having a capacitance type proximity sensor capable of obtaining favorable sensing sensitivity circumferentially.SOLUTION: A liquid crystal display device includes: a liquid crystal display panel 1; a transparent member 2 that covers a display surface of the liquid crystal display panel 1; a backlight 4 that is installed on a counter display surface side of the liquid crystal display panel 1; a frame 3 that has an opening portion 3a for fitting with the liquid crystal display panel 1; and a protection member 5 that is installed on a principal plane side of the backlight 4 on the opposite side to the liquid crystal display panel 1. In the backlight 4, a ground conductor plate 9 is provided on the display surface and the principal surface on the opposite side, and a capacitance type proximity sensor 6 is provided in loop shape apart from the ground conductor plate 9 on the outside thereof in planar view.

Description

  The present invention relates to a liquid crystal display device including a proximity sensor for activating a screen display when a human finger or the like approaches, or switching a still image display to a moving image display.

  Conventionally, in a liquid crystal display device used for, for example, a car navigation system, a tablet terminal, a smartphone, etc., when a human finger approaches the display screen in order to operate a touch panel provided in the liquid crystal display device, the screen display Or a proximity sensor for switching from still image display to moving image display. As this proximity sensor, there are a capacitance type sensor, an inductance type sensor, etc., but a capacitance that can detect the proximity of a human finger, which is an electrostatic conductor, as a change in capacitance without contact. A type sensor is preferably used.

  An example of a liquid crystal display device provided with a conventional proximity sensor is shown in FIG. 4 is an exploded plan view showing the main components of the liquid crystal display device. The liquid crystal display device includes a liquid crystal display panel 21, a transparent member 22 made of a glass plate or the like that covers the display surface of the liquid crystal display panel 21, and the like. A protection member 25 made of a flat plate-like backlight 24 installed on the opposite side of the liquid crystal display panel 21 and a plastic plate installed on the main surface of the backlight 24 opposite to the liquid crystal display panel 21; have. The transparent member 22 is a conductor made of a material such as a metal such as silver, an alloy, or a transparent conductor such as ITO (Indium Tin Oxide) so as to surround the periphery of the liquid crystal display panel 21 on the main surface on the viewer side. A capacitive proximity sensor 26 composed of the line 26b is formed. In FIG. 4, reference numeral 26 a denotes a power supply unit that supplies a pulse current to the capacitive proximity sensor 26, and 23 denotes a frame made of plastic or the like having an opening 23 a for fitting the liquid crystal display panel 21 and fixing the position. is there.

  FIG. 5 is a cross-sectional view of a liquid crystal display device constructed by assembling the main components shown in FIG. As shown in FIG. 5, from the viewer side (the side indicated by the white arrow in FIG. 4), a frame (frame) of the backlight 24 comprising the transparent member 22, the liquid crystal display panel 21, the backlight 24, aluminum, and the like. 28, a frame 23 having an opening 23a for fitting the liquid crystal display panel 21, and a protective member 25 are disposed. The frame body 28 is fitted into the frame 23 and fixed by means such as screwing, and the protection member 25 is fixed to the frame 23 by means such as screwing.

  The capacitive proximity sensor 26 of the liquid crystal display device of FIG. 4 operates, for example, as follows. First, when an external conductor such as a human finger approaches the conductor line 26b, capacitive coupling occurs between the conductor line 26b and the external conductor. At this time, since a new electric capacity is added to the conductor line 26b, the current value (charge amount) reflected from the conductor line 26b to the external control IC, LSI, etc. connected to the power supply portion 26a changes. To do. By detecting the changed current value as a change in voltage value by a control IC, LSI or the like, the proximity of an external conductor can be detected.

  As another conventional example, a pair of X-axis internal electrodes disposed in the detection reference plane so as to form a capacitance between adjacent electrodes and arranged opposite to each other in the X-axis direction belonging to the detection reference plane, and a detection reference plane A plurality of internal electrodes including a pair of Y-axis internal electrodes disposed opposite to each other in the Y-axis direction orthogonal to the X-axis direction, and an outer periphery of the plurality of internal electrodes so as to form a capacitance between adjacent electrodes. A capacitive proximity sensor device having an external electrode disposed has been proposed (see Patent Document 1).

International Publication No. 2011/087034

  However, the liquid crystal display device shown in FIGS. 4 and 5 has the following problems. As shown in the enlarged sectional view of the capacitive proximity sensor 26 in FIG. 6 and its peripheral part (A part in FIG. 5), the capacitive proximity sensor 26 overlaps the ground conductor plate 29 in a plan view, Since the capacitive proximity sensor 26 faces the main surface of the ground conductor plate 29 having a large area, the capacitive proximity sensor 26 and the ground conductor plate 29 are strongly electromagnetically coupled to each other. The electric field component of the mold proximity sensor 26 flows out as a current to an external grounding part (not shown) through the grounding conductor plate 29. As a result, there is a problem that the sensing sensitivity of the capacitive proximity sensor 26 decreases.

  Further, in the capacitive proximity sensor device described in Patent Document 1 (FIG. 12 of Patent Document 1), the sensor internal electrodes 112a to 112d overlap the grounded lower electrode 117 in plan view. It has the above-mentioned problems. In addition, since the external electrodes 113a to 113d are intermittently installed, the sensitivity of sensing may not be good over the entire circumference.

  Therefore, the present invention has been completed in view of the above problems, and is to provide a liquid crystal display device having a capacitive proximity sensor that can obtain good sensing sensitivity over the entire circumference.

  The liquid crystal display device of the present invention fits the liquid crystal display panel, a transparent member that covers the display surface of the liquid crystal display panel, a backlight installed on the side opposite to the display surface of the liquid crystal display panel, and the liquid crystal display panel And a protective member installed on the main surface side of the backlight opposite to the liquid crystal display panel, and the backlight is opposite to the display surface. A grounding conductor plate is provided on the main surface of the capacitor, and a capacitive proximity sensor is provided in a loop shape spaced apart from the grounding conductor plate in a plan view.

  In the liquid crystal display device of the present invention, preferably, the capacitive proximity sensor is provided in a space surrounded by the frame and the protective member.

  In the liquid crystal display device of the present invention, preferably, the frame has a conductor layer formed on the outer surface thereof.

  In the liquid crystal display device of the present invention, preferably, the conductor layer is electrically disconnected from the ground conductor plate.

  The liquid crystal display device of the present invention includes a liquid crystal display panel, a transparent member that covers the display surface of the liquid crystal display panel, a backlight installed on the side opposite to the display surface of the liquid crystal display panel, and a liquid crystal display panel for fitting A frame having an opening, and a protective member installed on the main surface opposite to the liquid crystal display panel of the backlight, and the backlight is grounded on the main surface opposite to the display surface Since the conductive plate is provided, and the capacitive proximity sensor is provided in a loop shape spaced apart from the grounded conductive plate in a plan view, the capacitive proximity sensor has a large area in the plan view. Since it is not opposed to the main surface of the ground conductor plate, electromagnetic coupling between the capacitive proximity sensor and the ground conductor plate can be effectively suppressed. As a result, the electric field component of the capacitive proximity sensor can be satisfactorily suppressed from flowing out as an electric current to the external grounding part through the ground conductor plate, so that the sensing sensitivity of the capacitive proximity sensor is kept high. .

  In the liquid crystal display device according to the present invention, preferably, the capacitive proximity sensor is provided in a space surrounded by the frame and the protective member. Therefore, it is possible to prevent the sensing sensitivity of the capacitive proximity sensor from fluctuating or decreasing.

  In the liquid crystal display device of the present invention, preferably, since the conductor layer is formed on the outer surface of the frame, the capacitive proximity sensor and the conductor layer are electrically capacitively coupled to each other. It functions as a part of the capacitive proximity sensor. That is, it is possible to prevent the capacitive proximity sensor from being electromagnetically coupled to the ground conductor plate or the like inside the liquid crystal display device, and to make the sensing of the capacitive proximity sensor go to the outside. In addition, since a capacitive component is generated between the capacitive proximity sensor and the conductor layer, the capacitive proximity sensor is less susceptible to external electromagnetic interference (EMI).

  In the liquid crystal display device of the present invention, preferably, since the conductor layer is electrically disconnected from the ground conductor plate, the electric field component of the capacitive proximity sensor is externally transmitted through the conductor layer and the ground conductor plate. As a result, it is possible to satisfactorily suppress the flow of current as a current to the grounding portion of the sensor, so that the sensing sensitivity of the capacitive proximity sensor is kept high.

FIG. 1 is a diagram showing an example of an embodiment of a liquid crystal display device according to the present invention, and is a plan view showing exploded main components of the liquid crystal display device. FIG. 2 is a sectional view of a liquid crystal display device constructed by assembling the main components shown in FIG. FIG. 3 is a diagram showing another example of the embodiment of the liquid crystal display device of the present invention, and is a cross-sectional view of the liquid crystal display device in which a conductor layer is formed on the outer surface of the frame. FIG. 4 is a diagram showing an example of a conventional liquid crystal display device, and is a plan view showing the main components of the liquid crystal display device in an exploded manner. FIG. 5 is a cross-sectional view of a liquid crystal display device constructed by assembling the main components shown in FIG. FIG. 6 is an enlarged cross-sectional view of the capacitive proximity sensor and its peripheral part of the liquid crystal display device of FIG.

  Hereinafter, embodiments of a liquid crystal display (LCD) of the present invention will be described with reference to the drawings. However, each drawing referred to below shows a main part for explaining the liquid crystal display device of the present invention among the constituent members in the embodiment of the liquid crystal display device of the present invention. Therefore, the liquid crystal display device according to the present invention can include well-known components such as a circuit board, a wiring conductor, a control IC, and an LSI not shown in the drawing.

  FIG. 1 is a diagram showing an example of an embodiment of a liquid crystal display device according to the present invention, and is a plan view showing exploded main components of the liquid crystal display device. The liquid crystal display device of the present invention is installed on the liquid crystal display panel 1, a transparent member 2 made of a glass substrate, a plastic substrate or the like that covers the display surface of the liquid crystal display panel 1, and the non-display surface side of the liquid crystal display panel 1. A backlight 4 made of an LED (Light Emitting Diode) element or the like, a frame 3 made of plastic or the like having an opening 3a for fitting the liquid crystal display panel 1, and a main body of the backlight 4 opposite to the liquid crystal display panel 1 And a protective member 5 made of plastic or the like installed on the side of the surface. The backlight 4 is provided with a ground conductor plate 9 (shown in FIG. 2) made of a metal such as aluminum or an alloy such as stainless steel on the main surface opposite to the display surface. The capacitive proximity sensor 6 is provided in a loop shape spaced apart from the outside. The loop-shaped capacitive proximity sensor 6 has a shape surrounding the entire periphery of the ground conductor plate 9. In FIG. 1, reference numeral 6a denotes a power feeding unit.

  With this configuration, since the capacitive proximity sensor 6 is not opposed to the main surface of the large-area ground conductor plate 9 in plan view, the capacitive proximity sensor 6 and the ground conductor plate 9 are electromagnetically coupled. Is effectively suppressed. As a result, the electric field component of the capacitive proximity sensor 6 can be satisfactorily suppressed from flowing out as an electric current to the external grounding part through the ground conductor plate 9, so that the sensing sensitivity of the capacitive proximity sensor 6 is high. Maintained. In FIG. 1, reference numeral 8 denotes a frame (frame) made of aluminum or the like for protecting the outer peripheral portion of the backlight 4.

  The capacitive proximity sensor 6 is made of metal such as gold (Au), silver (Ag), copper (Cu), aluminum (Al), chromium (Cr), nickel (Ni), iron (Fe), and the like. It is made of a material such as an alloy containing ITO and a transparent conductor such as ITO. For example, when the capacitive proximity sensor 6 is made of silver, a capacitive paste is applied by applying a silver paste mixed with a predetermined amount of silver particles to a paste containing alcohol, liquid resin, etc., and drying and firing. A sensor 6 can be provided. In addition to this coating / firing method, it can also be provided by a thin film forming method such as a plating method, a vapor deposition method, a CVD (Chemical Vapor Deposition) method, or a sputtering method. Furthermore, the capacitive proximity sensor 6 may be a conductor member or a metal member produced by sheet metal processing.

  It is preferable that the capacitive proximity sensor 6 is located at a position substantially opposite to the end face of the ground conductor plate 9. In this case, since the capacitive proximity sensor 6 is substantially opposed to the end surface of the ground conductor plate 9 having a small area, electromagnetic coupling between the capacitive proximity sensor 6 and the ground conductor plate 9 is further suppressed. The portion substantially opposite to the end surface of the ground conductor plate 9 has an extension axis of the main surface of the ground conductor plate 9 as a central axis, and an angle with the central axis is within a range of 45 degrees or less (a three-dimensional solid with an apex angle of 90 degrees or less). The angle may be within a range, and more preferably within a range of 30 degrees or less (a vertex angle within a solid angle range of 60 degrees or less).

  The distance between the capacitive proximity sensor 6 and the end face of the ground conductor plate 9 is preferably 5 mm or more. In this case, electromagnetic coupling between the capacitive proximity sensor 6 and the ground conductor plate 9 is effectively suppressed.

  In the liquid crystal display device of the present invention, the capacitive proximity sensor 6 is preferably provided in a space surrounded by the frame 3 and the protective member 5. In this case, since the capacitive proximity sensor 6 is less susceptible to external electromagnetic interference (EMI), the sensing sensitivity of the capacitive proximity sensor 6 can be prevented from fluctuating or decreasing. it can.

  In the liquid crystal display device of the present invention, as shown in FIG. 3, the frame 3 preferably has a conductor layer 10 formed on the outer surface thereof by a plating method or the like. In this case, the capacitive proximity sensor 6 and the conductor layer 10 are electrically capacitively coupled, and the conductor layer 10 functions as a part of the capacitive proximity sensor 6. That is, it is possible to suppress the capacitive proximity sensor 6 from being electromagnetically coupled to the ground conductor plate 9 or the like inside the liquid crystal display device, and to make the sensing of the capacitive proximity sensor 6 go to the outside. it can. In addition, since a capacitive component is generated between the capacitive proximity sensor 6 and the conductor layer 10, the capacitive proximity sensor 6 is unlikely to receive electromagnetic interference (EMI) from the outside.

  The conductor layer 10 is made of a metal such as chromium (Cr), nickel (Ni), iron (Fe), gold (Au), silver (Ag), copper (Cu), platinum (Pt), aluminum (Al), and the like. It consists of an alloy containing two or more kinds of metals. Chromium (Cr), nickel (Ni), gold (Au), and platinum (Pt) are preferable in terms of corrosion resistance and scratch resistance. The thickness of the conductor layer 10 is about 0.01 μm to 0.1 μm. The conductor layer 10 can be formed by a thin film forming method such as a plating method, a vapor deposition method, a CVD method, or a sputtering method, or a coating / firing method in which a metal paste containing metal particles such as silver is applied, dried, and fired.

  The portion of the outer surface of the frame 3 where the conductor layer 10 is formed is not particularly limited, but is a portion close to the capacitive proximity sensor 6 on the outer surface of the frame 3, In order for the capacitive proximity sensor 6 to be capacitively coupled satisfactorily, the distance between them is preferably 2 mm or less.

  In the liquid crystal display device of the present invention, it is preferable that the conductor layer 10 is not electrically connected to the ground conductor plate 9. In this case, the electric field component of the capacitive proximity sensor 6 can be satisfactorily suppressed from flowing out as a current to the external grounding part through the conductor layer 10 and the grounding conductor plate 9, so that the sensing of the capacitive proximity sensor 6 can be performed. High sensitivity is maintained. Note that “the conductor layer 10 and the ground conductor plate 9 are not electrically connected” means that they are in contact with each other or are not electrically connected by a wiring conductor or the like.

  Sensing sensitivity of the capacitive proximity sensors 6 and 26 was measured for the liquid crystal display device of the present invention shown in FIGS. 1 and 2 and the conventional liquid crystal display device shown in FIG. As the capacitive proximity sensor 6 in the liquid crystal display device of the present invention, a capacitive wire made of a conductor wire formed by coating a copper wire with a resin insulating material was used, and its wire diameter was 0.5 mm. A capacitance type proximity sensor 26 in a conventional liquid crystal display device was formed by a sputtering method, and its thickness was about 100 nm. The peak value of the pulse voltage input to the capacitive proximity sensors 6 and 26 is 1 V, the pulse width is 1 μs (s: seconds), and the input frequency is 1 MHz. Under this condition, the sensing sensitivity of the liquid crystal display device of the present invention was detected at a position where a human finger was close to the capacitive proximity sensor 6 by 100 mm. On the other hand, the conventional liquid crystal display device detected a finger at a position 20 mm closer to the capacitive proximity sensor 26 under the same conditions as described above.

  The liquid crystal display panel 1 of the present invention has the following configuration, for example. A TFT array side substrate on which a large number of pixel electrode portions including thin film transistor elements are formed and a color filter side substrate on which a color filter and a black matrix are formed are opposed to each other, and the substrates are separated by a predetermined distance. Thus, the substrates are bonded together, and liquid crystal is filled and sealed between the substrates. In general, the color filter side substrate is a common electrode (reference electrode) for forming a vertical electric field to be applied to the liquid crystal with the pixel electrode on the entire main surface facing the TFT element and the pixel electrode. ) Is formed. Further, red (R), green (G), and blue (B) color filters corresponding to the respective pixels are formed on the main surface of the color filter side substrate, and light passing through the respective pixels is transmitted. A black matrix that prevents mutual interference is formed so as to surround the outer periphery of the color filter.

  As the liquid crystal display panel 1, various types such as a TN (Twisted Nematic) type, an IPS (In-Plane Switching) type, and an FFS (Fringe Field Switching) type can be adopted.

  Such a liquid crystal display device is provided with a backlight 4 on the side opposite to the viewer side, through which transmitted light for forming an image on the liquid crystal display panel 1 is incident from the back side of the liquid crystal display panel 1. There are two types of the backlight 4. One method is an edge light method in which an LED (Light Emitting Diode) element as a light emitting element is arranged at the edge of the screen of the liquid crystal display panel 1. In this edge light system, light from LED elements arranged at the edge of the screen of the liquid crystal display panel 1 is guided to the entire screen by the light guide plate and uniformly dispersed. The edge light system can maintain good optical uniformity on a screen of up to about 60 inches and can realize a backlight 4 having a thickness of about 5 to 10 mm.

  The other type is a direct type, in which a large number of LED elements are arranged directly under a liquid crystal pixel, and light from the LED element is directly incident on the pixel. This direct type has no limitation on the screen size of the liquid crystal display panel 1 to which it is applied, and has low power consumption and good heat dissipation. The direct type has a tendency to make the backlight device thicker than the edge light method, but it can be suppressed to a thickness of about 10 mm or less. As a driving method for light emission of the LED element, a driving method for inputting a pulse current to the LED element by a PWM (Pulse Width Modulation) method is generally used.

  The capacitive proximity sensor 6 of the liquid crystal display device of the present invention operates, for example, as follows. First, when an external conductor such as a human finger approaches the capacitive proximity sensor, electrical capacitive coupling occurs between the capacitive proximity sensor 6 and the external conductor. At this time, since a new electric capacitance is added to the capacitive proximity sensor 6, a circuit board (not shown) connected to the capacitive proximity sensor 6 through the capacitive proximity sensor 6. The current value (charge amount) reflected from the capacitive proximity sensor 6 changes to the control IC, LSI, or the like. By detecting the changed current value as a change in voltage value by a control IC, LSI or the like, the proximity of an external conductor can be detected.

  In the liquid crystal display device of the present invention, a ground conductor plate 9 is provided on the main surface of the backlight 4 on the protective substrate 5 side. The ground conductor plate 9 is made of a metal such as aluminum or an alloy such as stainless steel. . Or it consists of insulating plates, such as a plastic plate which has a metal surface comprised by affixing a metal plate, a metal sheet, a metal film, etc. on the main surface. Further, instead of the ground conductor plate 9, a metal layer formed by applying and firing a metal paste containing metal particles such as silver particles, a metal layer formed by forming a metal such as aluminum by a plating method, etc. Can be used as

  In the liquid crystal display device of the present invention, the above-described capacitive proximity sensor 6 can activate a screen display when a human finger or the like approaches the liquid crystal display panel 1 or switch a still image display to a moving image display. it can. In addition, the brightness of the display screen can be increased. Further, when the liquid crystal display device includes a touch panel, the touch panel can be changed from the operation pause state to the operable state.

  When the liquid crystal display device is equipped with a touch panel, the touch panel includes a matrix switch method, a resistive film method, a surface acoustic wave method (ultrasonic method), an infrared method, an electromagnetic induction method, a surface type capacitance method, and a projection type. Various types such as a capacitance type can be adopted. Of these, the surface capacitance type is suitably used for touch panels of 10 inches or more. The capacitance detection unit in the surface type capacitive touch panel is composed of, for example, three layers of a transparent coating layer, a transparent conductive film, and a glass substrate, and the transparent conductive film is an electrode provided on four even portions of the glass substrate. Connected to. A uniform electric field is formed on the surface of the transparent coating layer on the glass substrate by the transparent conductive film. When an electrostatic conductor such as a human finger touches the surface of the capacitance detection unit, a weak current from the drive circuit passes through the electrodes at the four corners, the transparent conductive film, the transparent coating layer, and the finger. Thus, a closed circuit is formed in an equivalent circuit between the surrounding environment such as the ground and the drive circuit. The position of a finger or the like can be determined by calculating the ratio of currents at the electrodes at the four corners by the drive circuit. A surface-type capacitive touch panel can be manufactured at low cost because of its simple structure, and is suitably used for a large touch panel.

  A projected capacitive touch panel can detect multiple points of contact with a finger or the like. For example, a capacitance detection unit in a projected capacitive touch panel has a transparent insulator layer, a transparent electrode layer below it, and a substrate such as a glass substrate on which a drive circuit such as a control IC or control LSI is mounted. Comprising. The transparent electrode layer is formed so as to extend in a predetermined direction, and has a first layer having a mosaic first detection electrode pattern made of ITO or the like, and is orthogonal to the predetermined direction below the first layer. And a second layer having a mosaic-like second detection electrode pattern made of ITO or the like formed so as to extend in the direction in which it is formed. When an electrostatic conductor such as a human finger touches the surface of the capacitance detection unit, by detecting a change in capacitance of about 1 pF in the first and second detection electrode patterns in the vicinity thereof, The position of the contact portion can be detected two-dimensionally with high accuracy. Since the number of electrode terminals connected to the first and second detection electrode patterns is large, the manufacturing cost is increased. Moreover, since the electrical resistance of the first and second detection electrode patterns made of ITO or the like increases as the length increases, the resistance can be reduced by connecting to the metal wiring, and the size can be increased. This projected capacitive touch panel is capable of multipoint detection with a control IC, control LSI, etc. for detecting the position of the contact portion, and has high practicality. Therefore, the projected capacitive touch panel is preferably used for a tablet-type portable terminal or the like. it can.

  In addition, since the projected capacitive touch panel detects a change in capacitance in the first and second detection electrode patterns, an electrostatic conductor such as a human finger is attached to the capacitance detection unit. Even in the case of proximity without directly touching the surface, the position of the proximity portion can be detected two-dimensionally with high accuracy.

  It goes without saying that the liquid crystal display device of the present invention is not limited to the above-described embodiment, and includes appropriate design changes and improvements. For example, in the example of the above embodiment, an example is shown in which a capacitive proximity sensor having a substantially rectangular shape is provided at the peripheral edge of a substantially rectangular frame or the like included in a substantially rectangular liquid crystal display device. However, depending on the shape of the liquid crystal display device, a capacitive proximity sensor having a curved portion, a bent portion, or the like may be provided on the way to the extent that the effects of the present invention are not impaired. Moreover, there may be a plurality of power supply units, and for example, a power supply unit may be provided at the peripheral part of a substantially polygonal frame or the like at the center of each side.

  Although the liquid crystal display device has been described in the above embodiment, the capacitive proximity sensor of the present invention may be applied to other display devices. For example, organic EL (Electro Luminescence) display device, inorganic EL display device, FED (Field Emitting Display) display device, SED (Surface-conduction Electron-emitter Display) display device, GLV (Grating Light Valve) display device, PDP (Plasma) Display devices such as a display device, an electronic paper display device, a DMD (digital micro mirror device) display device, and a piezoelectric ceramic display device can be used.

  The liquid crystal display device of the present invention can be applied to various electronic devices. The electronic devices include a digital display wristwatch, a car route guidance system (car navigation system), a ship route guidance system, an aircraft route guidance system, a smartphone terminal, a mobile phone, a tablet terminal, a personal digital assistant (PDA), a video camera, Digital still camera, electronic notebook, electronic book, electronic dictionary, personal computer, copying machine, terminal device of game machine, television, product display tag, price display tag, industrial programmable display device, car audio, digital audio player, There are facsimiles, printers, automatic teller machines (ATMs), vending machines, and the like.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Transparent member 3 Frame 4 Backlight 5 Protective member 6 Capacitive proximity sensor 6a Feed part 8 Frame 9 Grounding conductor plate

Claims (4)

  A liquid crystal display panel, a transparent member covering the display surface of the liquid crystal display panel, a backlight installed on the side opposite to the display surface of the liquid crystal display panel, and a frame having an opening for fitting the liquid crystal display panel; A protective member installed on the main surface opposite to the liquid crystal display panel of the backlight, and the backlight is connected to the ground conductor plate on the main surface opposite to the display surface. A liquid crystal display device in which a capacitive proximity sensor is provided in a loop and spaced apart from the ground conductor plate in plan view.   The liquid crystal display device according to claim 1, wherein the capacitive proximity sensor is provided in a space surrounded by the frame and the protective member.   The liquid crystal display device according to claim 2, wherein a conductive layer is formed on an outer surface of the frame.   The liquid crystal display device according to claim 3, wherein the conductor layer is electrically disconnected from the ground conductor plate.