TW202416035A - Sensing device - Google Patents

Abstract

A sensing device includes a substrate, a light guide plate, a light emitting diode and a photosensitive element. The light guide plate includes a first portion, a second portion and a turning portion. The first portion is located on the side of the substrate. The first portion has at least one cavity. The second portion is located above the first surface of the substrate. The turning portion connects the first portion and the second portion. The light emitting diode is located in the cavity. The photosensitive element is located in the cavity.

Description

Sensing device

The present invention relates to a sensing device.

Foreign Object Detection (FOD) technology is often used to detect metallic foreign objects. For example, in wireless charging technology, foreign object detection technology can be used to detect metallic objects between the charger and the receiver to prevent metallic objects from affecting the efficiency of charging. However, since current foreign object detection technology can only detect metallic foreign objects, the scope of application of foreign object detection technology is narrow. For example, if you want to use existing foreign object detection technology to detect whether there is an obstruction on the surface of the glass, since the aforementioned obstruction may be objects of various materials (such as leaves, paper, etc.), you need to overcome the problem that current foreign object detection technology cannot detect materials other than metal.

The present invention provides a sensing device that can improve the problem that traditional foreign object detection technology cannot detect materials other than metal.

At least one embodiment of the present invention provides a sensing device. The sensing device includes a substrate, a light guide plate, a light emitting diode and a photosensitive element. The light guide plate includes a first part, a second part and a turning portion. The first part is located on the side of the substrate. The first part has at least one cavity. The second part is located on the first surface of the substrate. The turning portion connects the first part and the second part. The light emitting diode is located in the cavity. The photosensitive element is located in the cavity.

Based on the above, whether there is foreign matter on the first surface of the substrate can be sensed by the change of light.

FIG. 1A, FIG. 1B and FIG. 1C are cross-sectional schematic diagrams of a sensing device 10A in accordance with an embodiment of the present invention in different directions, wherein FIG. 1C corresponds to the position of the line A-A' in FIG. 1A and FIG. 1B, and FIG. 1A and FIG. 1B correspond to the positions of the line B-B' and the line C-C' in FIG. 1B, respectively. Referring to FIG. 1A to FIG. 1C, the sensing device 10A includes a substrate 100, a light guide plate 200, a light emitting diode 420 and a photosensitive element 430. In this embodiment, the sensing device 10A further includes a circuit board 410, a baffle structure 440, a reflective coating 300, a filter layer 310 and a prism structure 320 (or a brightness enhancement film).

In some embodiments, the material of the substrate 100 includes glass, quartz, organic polymer or opaque/reflective material (e.g., conductive material, metal, wafer, ceramic or other applicable material) or other applicable materials. In some embodiments, the substrate 100 is, for example, a cover plate of a display module, but the present invention is not limited thereto. The substrate 100 includes a first surface 102, a second surface 104 and a side surface 106 connecting the first surface 102 and the second surface 104.

The light guide plate 200 includes a first portion 210, a turning portion 220, and a second portion 230. In some embodiments, the material of the light guide plate 200 includes polymethylmethacrylate (PMMA), polycarbonate (PC), or other suitable materials.

The first portion 210 is located on the side surface 106 of the substrate 100 and is substantially parallel to the side surface 106. The first portion 210 has at least one cavity T. The second portion 230 is located on the first surface 102 of the substrate 100 and is substantially parallel to the first surface 102. The turning portion 220 connects the first portion 210 and the second portion 230. In some embodiments, the outer surface 212 of the first portion 210 and the outer surface 232 of the second portion 230 are respectively parallel to the side surface 106 and the first surface 102 of the substrate 100.

In some embodiments, the first portion 210, the turning portion 220, and the second portion 230 are connected in sequence and formed as one piece. In some embodiments, the first portion 210 and the second portion 230 extend along the first direction D1 and the second direction D2, respectively, wherein the first direction D1 is perpendicular to the second direction D2. In some embodiments, the angle θ1 between the outer surface 212 of the first portion 210 and the outer surface 222 of the turning portion 220 is 45 degrees, and the angle θ2 between the outer surface 232 of the second portion 232 and the outer surface 222 of the turning portion 220 is 45 degrees, but the present invention is not limited thereto. In other embodiments, the outer surface 222 of the turning portion 220 is a curved surface.

A plurality of light emitting diodes 420, a plurality of photosensitive elements 430, and a plurality of baffle structures 440 are located on the circuit board 410 and in the cavity T of the light guide plate 200. The light emitting diodes 420 and the photosensitive elements 430 are electrically connected to the circuit board 410. The light emitting diodes 420, the photosensitive elements 430, and the baffle structures 440 are arranged along the third direction D3, wherein the baffle structures 440 divide the cavity T of the light guide plate 200 into a plurality of first accommodating spaces 210a and second accommodating spaces 210b. The first accommodating spaces 210a and the second accommodating spaces 210b are arranged along the third direction D3. For example, the first accommodating spaces 210a and the second accommodating spaces 210b are arranged alternately. The LED 420 and the photosensitive element 430 are respectively located in the first accommodating space 210a and the second accommodating space 210b, and the blocking structure 440 is located between the LED 420 and the photosensitive element 430. In some embodiments, the blocking structure 440 includes a light absorbing material or a reflective material to prevent the adjacent LEDs 420 and photosensitive elements 430 from interfering with each other.

In this embodiment, since the light emitting diode 420 and the light sensing element 430 can share the same circuit board 410 and the same light guide plate 200, the manufacturing cost of the sensing device 10A can be saved.

In this embodiment, the first portion 210 of the light guide plate 200 includes a plurality of first protrusion structures P1 and a plurality of second protrusion structures P2 located in the cavity T. The first protrusion structures P1 and the second protrusion structures P2 overlap the light-emitting diode 420 and the light-sensing element 430, respectively. The barrier structure 440 is located between the first protrusion structures P1 and the second protrusion structures P2. In some embodiments, the width W1 of the first protrusion structure P1 is greater than the width W2 of the second protrusion structure P2.

The reflective coating 300 is located on the turning portion 220. For example, the reflective coating 300 is located on the outer surface 222 of the turning portion 220. In some embodiments, the reflective coating 300 extends from the outer surface 222 of the turning portion 220 to the outer surface 232 of the second portion 230. In some embodiments, the light L1 emitted by the LED 420 enters the light guide plate 200 from the light entrance area 214a of the first protrusion structure P1 of the light guide plate 200, is refracted at the turning portion 220 and enters the second portion 230, and then leaves the light guide plate 200 from the light exit area 234a of the second portion 230.

In addition, external light L2 (for example, light formed after the light L1 is reflected by an object on the first surface 102 of the substrate 100) enters the light guide plate 200 from the light entrance area 234b of the second part 230 of the light guide plate 200, and is refracted into the first part 210 at the turning portion 220, and then leaves the light guide plate 200 from the light exit area 214b of the second protruding structure P2 of the first part 210, and is received by the photosensitive element 430.

In this embodiment, the light is reflected back to the light guide plate 200 by the object on the first surface 102 of the substrate 100, and the light sensing element 430 receives the light and generates a signal. The object on the first surface 102 of the substrate 100 can be identified through the change of the signal. In some embodiments, the bottom of the light sensing element 430 is shielded to reduce the influence of stray light on the light sensing element 430. For example, the bottom of the light sensing element 430 is shielded by the circuit board 410 to reduce the influence of stray light on the light sensing element 430.

In this embodiment, since the light ray L1 and the light ray L2 can travel on the surface of the substrate 100, a thin object can be detected and the energy utilization of the light can be maximized.

In some embodiments, the light emitting area 234a and the light incident area 234b are, for example, different areas on the same surface (eg, the sensing surface S) of the second portion 230. In other words, the light emitting area 234a and the light incident area 234b may be coplanar.

In this embodiment, the light rays L1 and L2 are reflected by the reflective coating 300, but the present invention is not limited thereto. In other embodiments, other reflective structures other than the reflective coating 300 are disposed on the turning portion 220, and the light rays L1 and L2 are reflected by the aforementioned reflective structures.

The filter layer 310 is disposed on the second portion 230 and covers the light exiting area 234a and the light entering area 234b on the sensing surface S. In some embodiments, the LED 420 is an infrared LED, the photosensitive element 430 is an infrared photosensitive element, and the filter layer 310 is a visible light filter layer, wherein the visible light filter layer can be used to prevent visible light from interfering with the photosensitive element 430. In some embodiments, the material of the filter layer 310 includes ink or other suitable materials.

The prism structure 320 is located on the filter layer 310 and is used to improve the collimation degree of the light L1 leaving the light guide plate 200 and the light L2 entering the light guide plate 200 .

FIG. 2A and FIG. 2B are cross-sectional schematic diagrams of a sensing device 10B according to an embodiment of the present invention in different directions, wherein FIG. 2B corresponds to the position of the line A-A' in FIG. 2A, and FIG. 2A corresponds to the position of the line B-B' in FIG. 2B. It must be noted that the embodiments of FIG. 2A and FIG. 2B use the component numbers and partial contents of the embodiments of FIG. 1A to FIG. 1C, wherein the same or similar numbers are used to represent the same or similar components, and the description of the same technical contents is omitted. The description of the omitted parts can refer to the aforementioned embodiments, and will not be repeated here.

The difference between the sensing device 10B in FIGS. 2A and 2B and the sensing device 10A in FIGS. 1A to 1C includes that the first protruding structure P1A in the sensing device 10B includes a lens, and the first protruding structure P1A is, for example, a total internal reflection lens.

2A and 2B , the first portion 210 of the light guide plate 200 includes a plurality of first protrusion structures P1A and a plurality of second protrusion structures P2 located in the cavity T. The first protrusion structure P1A and the second protrusion structure P2 overlap the light emitting diode 420 and the photosensitive element 430, respectively. In some embodiments, the light L1 emitted by the light emitting diode 420 enters the light guide plate 200 from the light entrance area 214a of the first protrusion structure P1A of the light guide plate 200, is refracted at the turning portion 220 to enter the second portion 230, and then leaves the light guide plate 200 from the light exit area 234a of the second portion 230. The first protrusion structure P1A has the function of a lens and can be used to improve the collimation of the light L1 entering the light guide plate 200.

FIG3 is a cross-sectional schematic diagram of a sensing device 10C according to an embodiment of the present invention. It should be noted that the embodiment of FIG3 uses the component numbers and partial contents of the embodiments of FIG2A and FIG2B , wherein the same or similar numbers are used to represent the same or similar components, and the description of the same technical contents is omitted. The description of the omitted parts can be referred to the aforementioned embodiments, and will not be repeated here.

The difference between the sensing device 10C of FIG. 3 and the sensing device 10B of FIG. 2A and FIG. 2B includes that the outer surface 222A of the turning portion 220 of the sensing device 10C is a curved surface.

3 , the outer surface 222A of the turning portion 220 is a curved surface, and the reflective coating 300 is located on the turning portion 220. For example, the reflective coating 300 is located on the outer surface 222A of the turning portion 220. In some embodiments, the reflective coating 300 extends from the outer surface 222A of the turning portion 220 to the outer surface 232 of the second portion 230. The outer surface 222A is a curved surface to improve the degree of light collimation.

FIG. 4A is a schematic cross-sectional view of a sensing device 10D according to an embodiment of the present invention. FIG. 4B is a partially enlarged schematic view of region R of FIG. 4A. FIG. 4C is a schematic cross-sectional view along line A-A’ of FIG. 4B. FIG. 4D is a partial three-dimensional schematic view of a sensing device 10D according to an embodiment of the present invention. It must be noted that the embodiments of FIG. 4A to FIG. 4D use the component numbers and partial contents of the embodiments of FIG. 1A to FIG. 1C, wherein the same or similar numbers are used to represent the same or similar components, and the description of the same technical contents is omitted. For the description of the omitted parts, please refer to the aforementioned embodiments, which will not be elaborated here.

4A to 4D , in this embodiment, the sensing device 10D includes a substrate 100 , a light guide plate 200 , a light emitting diode 420 , a photosensitive element 430 , an outer frame 510 and a decorative element 520 .

Please refer to Figures 4A to 4D, the light guide plate 200, the light emitting diode 420 and the photosensitive element 430 are arranged in the accommodation space 510a of the outer frame 510. In some embodiments, the light guide plate 200 is fixed to the outer frame 510 by a fixing member (not shown), and the aforementioned fixing member is, for example, a clamp, a screw or other suitable components. In some embodiments, the light guide plate 200 is directly fixed to the outer frame 510 by ultrasonic welding. In some embodiments, a reflective coating (not shown) is provided on the light guide plate 200. In some embodiments, a display module (not shown) is provided in the accommodation space 510b of the outer frame 510, and the substrate 100 can serve as a cover plate for the display module. In some embodiments, the accommodating space 510a and the accommodating space 510b are separated from each other, but the present invention is not limited thereto. In other embodiments, the accommodating space 510a and the accommodating space 510b are connected together. The ornament 520 is disposed on the outer frame 510 and is used to cover the frame of the outer frame 510.

In some embodiments, the sensing device 10D is, for example, a head-up display device for a vehicle, and the light guide plate 200, the light-emitting diode 420, and the photosensitive element 430 in the sensing device 10D can be used to sense whether there are foreign objects (such as business cards, credit cards, pens, invoices, etc.) on the surface of the substrate 100. Since the light rays L1 and the light rays L2 can travel on the surface of the substrate 100, thin and light foreign objects (such as paper) can be detected.

In addition, since the light guide plate 200, the light emitting diode 420 and the photosensitive element 430 are directly disposed in the outer frame 510 for accommodating the display module, there is no need to set up an additional camera for foreign object detection. Therefore, in addition to not needing to use high-cost camera image recognition technology, the space required for setting up an additional camera can also be saved.

FIG5 is a cross-sectional schematic diagram of a sensing device 10E according to an embodiment of the present invention. It should be noted that the embodiment of FIG5 uses the component numbers and partial contents of the embodiments of FIG1A to FIG1C, wherein the same or similar numbers are used to represent the same or similar components, and the description of the same technical contents is omitted. The description of the omitted parts can be referred to the aforementioned embodiments, and will not be repeated here.

The difference between the sensing device 10E in FIG. 5 and the sensing device 10A in FIG. 1A to FIG. 1C includes that the sensing device 10E further includes a display module 610 .

5 , the display module 610 is located below the second surface 104 of the substrate 100. The circuit board 410 is located below the display module 610. The electronic components 412a-412f are disposed on the circuit board 410, and the display module 610 is electrically connected to at least one of the electronic components 412a-412f through the circuit board 620. In some embodiments, the electronic components 412a-412f include chips, passive components, or other electronic components.

In some embodiments, the circuit board 410 is, for example, a system circuit board of the display module 610, and the light-emitting diode 420 and the light-sensing element 430 are disposed on the system circuit board. Therefore, the production cost of the sensing device 10E can be saved.

10A, 10B, 10C, 10D, 10E: sensing device 100: substrate 102: first surface 104: second surface 106: side surface 200: light guide plate 210: first part 210a: first storage space 210b: second storage space 212, 222, 232, 222A: outer surface 214a, 234b: light entrance area 214b, 234a: light exit area 220: turning part 230: second part 300: reflective coating 310: filter layer 320: prism structure 410: circuit board 412a~412f: electronic components 420: light-emitting diode 430: photosensitive element 440: baffle structure 510: outer frame 510a, 510b: storage space 520: decoration 610: display module A-A’, B-B’, C-C’: line D1: first direction D2: second direction D3: third direction L1, L2: light P1, P1A: first protrusion structure P2: second protrusion structure R: area S: sensing surface T: cavity W1, W2: width θ1, θ2: angle

Figures 1A, 1B and 1C are schematic cross-sectional views of a sensing device according to an embodiment of the present invention in different directions. Figures 2A and 2B are schematic cross-sectional views of a sensing device according to an embodiment of the present invention in different directions. Figure 3 is a schematic cross-sectional view of a sensing device according to an embodiment of the present invention. Figure 4A is a schematic cross-sectional view of a sensing device according to an embodiment of the present invention. Figure 4B is a partially enlarged schematic view of Figure 4A. Figure 4C is a schematic cross-sectional view along line A-A’ of Figure 4B. Figure 4D is a partial three-dimensional schematic view of a sensing device according to an embodiment of the present invention. Figure 5 is a schematic cross-sectional view of a sensing device according to an embodiment of the present invention.

10A: Sensing device

100: Substrate

102: First page

104: Second side

106: Side

200: Light guide plate

210: Part 1

210a: The first storage space

212,222,232: External surface

214a: Light entry area

234a: Light exit area

220: Turning point

230: Part 2

300:Reflective coating

310: Filter layer

320: Prismatic structure

410: Circuit board

420: LED

A-A’: line

D1: First direction

D2: Second direction

D3: Third direction

L1: Light

S: Sensing surface

T: Cavity

θ1,θ2: angle

Claims (10)

A sensing device comprises: a substrate; a light guide plate comprising: a first portion located on a side of the substrate, wherein the first portion has at least one cavity; and a second portion located on a first surface of the substrate; and a turning portion connecting the first portion and the second portion; a light-emitting diode located in the at least one cavity; and a photosensitive element located in the at least one cavity. The sensing device as described in claim 1 further includes: A reflective coating film located on the turning portion. A sensing device as described in claim 2, wherein the turning portion includes a curved surface. A sensing device as described in claim 2, wherein the reflective coating extends from the turning portion to the second portion. The sensing device as described in claim 1, wherein the first portion includes a first protrusion structure located in the at least one cavity, and the first protrusion structure overlaps the light-emitting diode. A sensing device as described in claim 5, wherein the first portion includes a second protrusion structure overlapping the photosensitive element, wherein the width of the first protrusion structure is greater than the width of the second protrusion structure, and the first protrusion structure includes a lens. The sensing device as described in claim 6 further includes: A baffle structure located between the light-emitting diode and the photosensitive element and between the first protrusion structure and the second protrusion structure. A sensing device as described in claim 7, wherein the baffle structure includes a light-absorbing material or a reflective material. The sensing device as described in claim 1 further includes: a filter layer disposed on the second portion; and a prism structure located on the filter layer. The sensing device as described in claim 9 further comprises: a display module located below the substrate; and a system circuit board located below the display module, and the display module is electrically connected to the system circuit board, wherein the light-emitting diode and the photosensitive element are arranged on the system circuit board.

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