JP2017167203A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device which can increase the detection performance of an infrared detection sensor and can improve the appearance.SOLUTION: The display device includes: a display panel having a display surface; an infrared detection sensor having an infrared light emitter 6a and an infrared light emitter 6b on at least one end of the display panel; a transparent member 1 over the display surface and the infrared detection sensor; a first light shielding layer 9a located on a side of the transparent member 1 adjacent to the infrared detection sensor; and a second light shielding layer 9b located on a side of the first light shielding layer 9a adjacent to the infrared detection sensor, the second light shielding layer 9b exhibiting a smaller visible light transmittance than the first light shielding layer 9a and having an infrared passage window 9b1 for receiving passage of infrared radiation from the infrared detection sensor.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a display device.

  2. Description of the Related Art Conventionally, in a liquid crystal display (LCD) used for, for example, a car navigation system, a tablet terminal, and a smartphone, a human finger is close to the display screen in order to operate a touch panel provided on the LCD. Sometimes, a proximity sensor for driving the display such as starting the screen display, displaying a hidden display unit such as an icon or a touch button on the display surface, or switching the still image display to the moving image display may be provided. .

  As this proximity sensor, an infrared detection sensor is known, and conventionally, a display device including the infrared detection sensor is known (Patent Document 1). The display device of Patent Document 1 includes a display panel in which infrared detection sensors are provided at both ends, a transparent member that covers the display panel and the infrared detection sensor, a frame that has an opening for fitting the display panel, and a display panel And a protective member provided on the side opposite to the display surface.

  Patent Document 1 describes that a portion of the transparent member that covers the infrared detection sensor is provided with a light shielding layer that transmits infrared rays but does not transmit visible light so that the inside is not visually recognized.

JP-A-2015-179054

  In the display device of Patent Document 1, a portion of the transparent member that covers the infrared detection sensor is provided with a light-shielding layer that transmits infrared rays but does not allow visible light to pass through, so that the inside is not visually recognized. Increasing the transmittance of the light source improves the detection performance of the infrared detection sensor, but also reduces the light shielding performance of the light shielding layer, making the infrared detection sensor easier to visually recognize from the outside and causing the appearance to deteriorate.

  The present invention provides a display device capable of improving the detection performance of an infrared detection sensor and improving the appearance.

  The display device of the present invention includes a display panel having a display surface, an infrared detection sensor provided at at least one end of the display panel, a transparent member covering the display surface and the infrared detection sensor, and the transparent member. A first light-shielding layer disposed on the infrared detection sensor side, and a second light-shielding layer having a visible light transmittance lower than that of the first light-shielding layer and provided on the infrared detection sensor side of the first light-shielding layer. The second light-shielding layer has an infrared passage window through which infrared rays of the infrared detection sensor pass.

  In the display device of the present invention, the detection performance of the infrared detection sensor can be improved.

The embodiment of the liquid crystal display device as a display device is shown, and is a plan view showing the main components of the liquid crystal display device in an exploded manner. FIG. 2 shows a liquid crystal display device constructed by assembling the main components shown in FIG. 1, wherein (a) is a longitudinal sectional view and (b) is a plan view. (A) is the top view which looked at the transparent member from the display panel side (viewed from the 3A-3A line of (b)), (b) is explanatory drawing which shows an infrared detection sensor and its vicinity, (c) These are explanatory drawings which show the state where the thickness of the 2nd light shielding layer is gradually thinning toward the infrared passage window 9b1. In order to explain the effect of the present embodiment, (a) is an explanatory diagram when there is no second light-shielding layer, and (b) is an explanatory diagram when there is a second light-shielding layer. Another embodiment of the display device is shown, and is an explanatory view showing a relationship between a display region and a light shielding layer. FIG. 4 shows still another embodiment of the display device, where (a) is an explanatory diagram for explaining the formation position of the second light shielding layer on the first light shielding layer, and (b) is a view of the transparent member from the display panel side. FIG. FIG. 32 is a diagram illustrating still another embodiment of the display device, and is an explanatory diagram illustrating a relationship between an infrared transmission region and a display panel arrangement position.

  Hereinafter, embodiments of a display device will be described with reference to the drawings. However, each figure referred below shows the main part for demonstrating a display apparatus. Therefore, the display device may include well-known components such as a circuit board, a wiring conductor, a control IC, and an LSI that are not shown in the drawing.

  As shown in FIGS. 1 and 2, a liquid crystal display device (LCD) as a display device includes a transparent member 1 made of a glass plate, a liquid crystal display panel 2 having a display surface 2a covered with the transparent member 1, and a liquid crystal display. A frame 3 made of plastic or the like having an opening 3a for fitting the panel 2, a flat backlight 4 installed on the side opposite to the display surface 2a of the liquid crystal display panel 2, and a liquid crystal display panel of the backlight 4 2 and a protective member 5 made of plastic or the like installed on the opposite side.

  As shown in FIG. 2, infrared detection sensors 6 that detect a detection target 9 such as a human finger close to the display surface 2 a are provided at both left and right ends of the liquid crystal display panel 2.

  The infrared detection sensor 6 includes two infrared light emitting elements 6a and one infrared light receiving element 6b. The infrared light emitting element 6a and the infrared light receiving element 6b are normal to the center h of the display surface 2a. It is installed tilted to face the direction. The center of the display surface 2a is not limited to the exact center of the display surface 2a, but is a center line extending in the vertical direction of the display surface 2a, and detects infrared rays toward the vertical surface of the display surface 2a including the center line. The sensor 6 may be tilted. With this configuration, it is possible to satisfactorily detect the detected body 9 such as a human hand close to the display surface 2a (transparent member 1) of the liquid crystal display panel 2.

The infrared detection sensor 6 is installed on a protruding member 8 attached to the end of the surface opposite to the display surface 2a of the liquid crystal display panel 2 by means such as bonding with an adhesive or screwing. . The overhang member 8 is attached to the non-display surface 2b of the liquid crystal display panel 2 by a double-sided adhesive tape such as a transparent adhesive or a highly transparent adhesive transfer tape (OCA). The overhang member 8 is made of a material such as plastic, a metal such as aluminum (Al), copper (Cu), stainless steel, brass (Cu—Zn alloy) or an alloy, or a ceramic such as alumina ceramic. The projecting member 8 has, for example, a portion projecting from the non-display surface 2b of the liquid crystal display panel 2 inclined toward the center of the display surface 2a, and the infrared detection sensor 6 is installed at the site. Yes. In FIG. 2, reference numeral 7 denotes a conductor plate made of aluminum (Al) or the like provided on the main surface of the backlight 4 on the side opposite to the liquid crystal display panel 2.

  A partition wall 11 is provided between the infrared light emitting element 6a and the infrared light receiving element 6b as shown in FIGS. 2 (b) and 3 (b). In this case, it is possible to prevent the infrared light emitted from the infrared light emitting element 6a from being directly received by the infrared light receiving element 6b. The partition 11 is made of a material such as plastic, metal (alloy) such as aluminum (Al), copper (Cu), stainless steel, brass (Cu-Zn alloy), or ceramic such as alumina ceramic. The partition wall 11 is provided on a substrate such as a circuit board on which the infrared light emitting element 6a and the infrared light receiving element 6b are mounted by means such as adhesion and screwing. Note that the substrate may include known electronic components such as a wiring conductor, a control IC, and an LSI. This substrate is disposed on the overhang member 8.

  Of the infrared rays radiated from the infrared light emitting element 6a, the component emitted at a low angle in the direction of the infrared light receiving element 6b is shielded by the partition wall 11 as shown in FIG. Direct reception is effectively suppressed. FIG. 3B is a cross-sectional view taken along line 3B-3B in FIG.

  The infrared detection sensor 6 is covered with the transparent member 1, but a light shielding layer 9 is provided at a portion of the transparent member 1 that covers the infrared detection sensor 6.

  As shown in FIG. 3, the light shielding layer 9 has a first light shielding layer 9a disposed on the infrared detection sensor 6 side of the transparent member 1, and a visible light transmittance lower than that of the first light shielding layer 9a. And a second light shielding layer 9b provided on the light shielding layer 9a on the infrared detection sensor 6 side. 3A is a plan view seen from the line 3A-3A in FIG. 3B, and shows the back surface side of the transparent member 1. FIG.

  In FIG. 3, the light shielding layer 9 is annularly provided on the outer peripheral portion of the transparent member 1, and the display portion 2 a of the liquid crystal display panel 2 is located in the light shielding layer 9. Moreover, the 1st light shielding layer 9a is cyclically | annularly provided in the outer peripheral part of the transparent member 1, and the 2nd light shielding layer 9b is provided on the 1st light shielding layer 9a except for the opening part 9b1.

  The second light shielding layer 9b is provided with three openings through which the infrared light emitting element 6a and the infrared light receiving element 6b of the infrared detection sensor 6 pass, and these openings serve as infrared passage windows 9b1. Yes.

  That is, the infrared detection sensor 6 includes two infrared light emitting elements 6a and an infrared light receiving element 6b disposed between the two infrared light emitting elements 6a with a predetermined interval therebetween. The two light shielding layers 9b have infrared passage windows 9b1 in the infrared radiation direction from the two infrared light emitting elements 6a to the outside and the infrared light receiving direction to the infrared light receiving element 6b, respectively.

  The first light shielding layer 9a that hardly allows visible light to pass through is exposed in the infrared passage window 9b1. As described above, since the first light shielding layer 9a easily transmits infrared light, infrared light is emitted between the infrared light emitting element 6a and the infrared light receiving element 6b and the outside of the transparent member 1 through the infrared passage window 9b1. Light reception can be performed satisfactorily. The partition 11 described above extends from between the infrared light emitting element 6a and the infrared light receiving element 6b toward the respective infrared passage windows 6b1.

The second light shielding layer 9b is made of a material having a low visible light transmittance. Infrared rays may be passed. The second light-shielding layer 9b is preferably of a color that efficiently absorbs visible light such as black, black-brown, dark brown, dark blue, and dark purple. For example, GLS-HF97 black manufactured by Teikoku Ink. The first light shielding layer 9a allows infrared rays to pass more easily than the second light shielding layer 9b, and is, for example, IRX-001 Victoria manufactured by Teikoku Ink. The first light shielding layer 9a and the second light shielding layer 9b can be formed by a screen printing method. In addition, in the site | part corresponding to the display area of the display surface 2a of the transparent member 1, the light shielding layer is not formed in order to let visible light pass.

  The part of the transparent member covering the infrared detection sensor is usually provided with a light shielding layer that allows infrared light but not visible light so that the inside is not visually recognized. While the detection performance of the infrared detection sensor can be improved, the light shielding performance of the light shielding layer is lowered, the infrared detection sensor is easily visible from the outside, and the appearance tends to deteriorate.

  In the present embodiment, the infrared rays from the infrared detection sensor pass through the infrared passage window 9b1 of the second light shielding layer 9b and pass through the first light shielding layer 9a having a high infrared transmittance (visible light transmittance) to the outside. Radiation or infrared rays from the outside pass through the first light shielding layer 9a having a high infrared transmittance, pass through the infrared passage window 9b1 of the second light shielding layer 9b, and are detected by the infrared light receiving element 6b. Thus, the detection performance of the infrared detection sensor 6 can be improved.

  In addition, by providing the infrared light passing window 9b1 of the second light shielding layer 9b at the portion where the infrared detection sensor 6 receives and emits light, the first light shielding layer 9a and the second light shielding layer 9b emit visible light other than the infrared light passing window 9b1. The light can be shielded efficiently, the inside other than the display unit 2a can be hardly seen from the outside, and the appearance can be improved.

  Furthermore, the first light shielding layer 9a having a high visible light transmittance from the outside, and the second light shielding layer 9b having a visible light transmittance lower than that of the first light shielding layer 9a are provided on the detection sensor 6 side of the first light shielding layer 9a. The presence of the infrared passage window 9b1 of the second light-shielding layer 9b is hardly visible from the outside, and the appearance can be improved.

  In addition, as shown in FIG. 4A, when one light shielding layer 9 is formed, the infrared rays that have passed through the light shielding layer 9 are reflected by the interface between the light shielding layer 9 and the transparent member 1. In the present embodiment, the second light-shielding layer 9b having a low transmittance is disposed on the infrared light source side, so that the light-shielding layer 9 is disposed as shown in FIG. 4B. In (9a), stray light can be reduced and malfunctions can be reduced.

  Further, as shown in FIG. 2, it is desirable that the position of the overhang member 8 is adjusted to be a shielding plate so that the light from the backlight 4 is not irradiated to the infrared passage window 9b1. Thereby, the presence of the infrared passage window 9b1 of the second light-shielding layer 9b is further less visible from the outside, and the appearance can be improved.

  Furthermore, in FIG.3 (c), the thickness of the 2nd light shielding layer 9b is gradually thin toward the infrared rays passage window 9b1. That is, the thickness of the second light shielding layer 9b other than the vicinity of the infrared transmission window 9b1 is substantially constant, but the thickness of the second light shielding layer 9b near the infrared transmission window 9b1 is gradually reduced toward the infrared transmission window 9b1. . In such a display device, since the visible light transmission amount gradually increases toward the infrared passage window 9b1, the presence of the infrared passage window 9b1 can be made difficult to be visually recognized from the outside.

Main members of the display device will be described. The infrared light emitting element 6a in the LCD of the present embodiment emits infrared light having a light wavelength of about 700 to 1000 nm, more specifically, infrared light having a light wavelength of about 850 to 950 nm. The infrared detection sensor, for example, activates screen display when a human finger or the like approaches the display surface 2a of the liquid crystal display panel 2 at a distance of about several tens of centimeters or less. It is used as a start switch for driving a display such as displaying a hidden display unit or the like, or switching a still image display to a moving image display.

  The LCD of this embodiment is manufactured as follows. An array side substrate composed of a glass substrate or the like on which a number of pixel electrode portions including thin film transistor (TFT) elements are formed and a color filter side substrate composed of a glass substrate or the like on which a color filter and a black matrix are formed are mutually connected. The substrates are bonded to each other at a predetermined interval, 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. In the case of an IPS (In-Plane Switching) type LCD, the common electrode is formed in the same plane as the pixel electrode in the pixel electrode portion of the array side substrate, thereby generating a horizontal electric field. In the case of an FFS (Fringe Field Switching) type LCD, the common electrode is formed on the pixel electrode portion of the array side substrate with an insulating layer sandwiched above or below the pixel electrode, thereby generating an edge field (Fringe Field). It will be generated.

  In addition, 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 mutually passes. A black matrix that prevents interference with the color filter is formed so as to surround the outer periphery of the color filter.

  When the LCD of this embodiment is a transmissive LCD, transmitted light for forming an image on the liquid crystal display panel 2 is incident on the side opposite to the viewer side from the side opposite to the display surface 2b of the liquid crystal display panel 2. A backlight 4 is provided. Further, when the LCD according to the present embodiment is a reflective LCD, the backlight 4 may not be provided. 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 2. 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 2 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 backlight 4 is fitted in a metal frame 24a made of aluminum or the like. The metal frame 4a is fitted into the frame 3 and fixed by means such as screwing, and the protection member 5 is fixed to the frame 3 by means such as screwing.

  FIG. 5 shows another embodiment of the display device. In this embodiment, the first light shielding layer 9a and the second light shielding layer 9b provided in the transparent member 1 have openings at the same position. The opening includes the display area G of the display panel 12, and the first light shielding layer 9 a and the second light shielding layer 9 b are located outside the display area G.

In other words, each of the first light shielding layer 9a and the second light shielding layer 9b has an opening,
When viewed in plan, the display region G of the display panel 12 is located inside the portion where the openings of the first light shielding layer 9a and the second light shielding layer 9b overlap.

  In such an embodiment, even if a dimensional deviation or assembling deviation of each member occurs, the display area 12a is not obstructed by the light shielding layer 9, and the display as intended can be performed over the entire display area G. it can.

  In FIG. 5 and the subsequent drawings, the display panel and the backlight are described as one display panel 12 for simplification of the drawing.

  FIG. 6 shows still another embodiment of the display device. In this embodiment, the second light shielding layer 9b is formed inside the edge of the first light shielding layer 9a.

  That is, the first light shielding layer 9a is formed in an annular shape on the transparent member 1, and has an outer peripheral edge 9a1 and an inner peripheral edge 9a2, and the second light shielding layer 9b is formed by the outer peripheral edge 9a1 of the first light shielding layer 9a and It is located inward by L from the inner peripheral edge 9a2. 6B shows the back side of the transparent member 1, and the alternate long and short dash line in FIG. 6B shows the display area 12a.

  In such a form of FIG. 6, even if variation occurs in the coating process of the second light shielding layer 9b, the edge of the second light shielding layer 9b that is more easily visible from the outside than the first light shielding layer 9a is the first light shielding layer 9a. Since it does not protrude from the surface, a display device that does not impair the appearance quality can be manufactured.

  FIG. 7 shows still another embodiment of the display device. In this embodiment, the display panel 12 is arranged at a position that does not block the infrared rays that pass through the infrared passage window 9b1.

  That is, within the angle formed by the two infrared light emitting elements 6a and the infrared radiation direction from the infrared light emitting elements 6a to the outside, and the angle formed by the infrared light receiving element 6b and the infrared light receiving direction to the infrared light receiving element 6b, the display is performed. Panel 12 is not located. As a result, infrared rays are not blocked by the display panel 12, and the detected object 9 such as a human hand close to the display surface 2a of the liquid crystal display panel 2 can be satisfactorily caused by the infrared light emitting element 6a and the infrared light receiving element 6b. Can be detected.

  The display device is not limited to the above embodiment, and may include appropriate design changes and improvements.

The display device is not limited to a liquid crystal display device (LCD), but is an organic EL (Electro Luminescence) device, an inorganic EL device, an FED (Field Emitting Display), or an SED.
(Surface-conduction Electron-emitter Display), GLV (Grating Light Valve) device, PDP (Plasma Display) device, electronic paper display device, DMD (Digital micro Mirror Device), piezoelectric ceramic display, etc. .

  The display device can be applied to various electronic devices. The electronic devices include automobile route guidance system (car navigation system), ship route guidance system, aircraft route guidance system, smartphone terminal, mobile phone, tablet terminal, personal digital assistant (PDA), video camera, digital still camera, electronic Notebook, electronic book, electronic dictionary, personal computer, copier, game device terminal, television, product display tag, price display tag, industrial programmable display, car audio, digital audio player, facsimile, printer, cash There are automatic teller machines (ATMs), vending machines, head-up displays, digital display watches, and the like.

  In the above embodiment, the infrared detection sensors are provided at both ends of the display panel. However, the infrared detection sensors may be provided at least at one end.

  Moreover, although the form which provided the 1st light shielding layer 9a and the 2nd light shielding layer 9b in the back surface of the transparent member 1 was demonstrated, if it is the back surface of the transparent member 1, you may provide away from the transparent member 1. FIG.

  Furthermore, it is needless to say that a third light shielding layer other than the first light shielding layer 9a and the second light shielding layer 9b may be provided.

  Furthermore, although the annular first light shielding layer 9a is provided on the outer periphery of the transparent member 1 and the annular second light shielding layer 9b is provided on the first light shielding layer 9a, the second light shielding layer 9b is transparent. The first light shielding layer 9a may be interposed only in the infrared light passing window 9b1 of the second light shielding layer 9b and the vicinity thereof.

DESCRIPTION OF SYMBOLS 1 Transparent member 2, 12 Liquid crystal display panel 2a, 12a Display surface 3 Frame 4 Backlight 6 Infrared detection sensor 6a Infrared light emitting element 6b Infrared light receiving element 9 Light shielding layer 9a First light shielding layer 9b Second light shielding layer 9b1 Infrared passage window 11 Partition G Display area

Claims (6)

A display panel having a display surface; an infrared detection sensor provided at at least one end of the display panel;
A transparent member covering the display surface and the infrared detection sensor;
A first light shielding layer disposed on the infrared detection sensor side of the transparent member;
A visible light transmittance lower than that of the first light shielding layer, and a second light shielding layer provided on the infrared detection sensor side of the first light shielding layer, and
The display device, wherein the second light shielding layer has an infrared passage window through which infrared rays of the infrared detection sensor pass.   The display device according to claim 1, wherein a thickness of the second light shielding layer is gradually reduced toward the infrared passage window.   The infrared detection sensor includes an infrared light emitting element and an infrared light receiving element at a predetermined interval, and the second light shielding layer includes an infrared radiation direction from the infrared light emitting element to the outside and an infrared ray to the infrared light receiving element. The display device according to claim 1, wherein each of the infrared passage windows is provided in a light receiving direction.   2. The first light-shielding layer and the second light-shielding layer of the transparent member have an opening at the same position, and the opening includes a display area of the display panel. The display apparatus in any one of thru | or 3.   5. The display device according to claim 1, wherein the second light shielding layer is disposed on an inner side than an edge of the first light shielding layer.   The display device according to claim 1, wherein the display panel is disposed at a position that does not block infrared rays that pass through the infrared passage window.

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