TWI696007B - Optical sensing protective shell - Google Patents

Abstract

The invention provides a protective casing for optical sensing, which comprises an upper casing, a lower casing and a light guide plate, the three of which can cover a smart device, the upper and lower casings are buckled and combined with each other, and the light guide plate is arranged on the upper casing The upper part is provided with a fingerprint sensing area which can be pressed by fingers, and a first reflecting part and a second reflecting part are respectively arranged on both sides of the light guide plate; a light source, a signal amplifier and a photosensitive element are arranged on the lower case The optical signal provided by the light source is introduced into the light guide plate through the first reflection part, and transmitted through the internal total reflection effect in the light guide plate, and then exported to the photosensitive element through the second reflection part and the signal amplifier. The photosensitive element processes the optical signal into a fingerprint image Send to smart device. A smart device that does not originally have a fingerprint detection function can be equipped with a full-screen fingerprint sensing function after being installed with the optical sensing protective case of the present invention, and is easy to maintain, so the present invention is both practical and beautiful.

Description

Optical sensing protective shell

The invention relates to a protective shell, in particular to an optical sensing protective shell.

With the evolution of technology, more and more confidential information and personal data are stored in smart devices, and how to protect information from outflow is a very important security issue, including how to prevent the passwords of smartphones and computers from being cracked. In addition to digital passwords and graphic passwords, biometrics is currently prevalent, including fingerprints, irises, facial images, etc. Among them, fingerprint recognition uses unique fingerprint information on human fingers for identification, due to its security and convenience The advantages are widely used.

Almost all modern smartphones have added fingerprint recognition function, which can provide fingerprint encryption and fingerprint unlocking. However, all current smartphones are designed with a fingerprint sensing area on the phone case, for example, the Home button is also the fingerprint sensing area. , But this area is too small, only one fingerprint can be sensed at a time. If the photosensitive element inside the fingerprint sensing area is damaged, it is necessary to send the entire mobile phone for repair, which is time-consuming and expensive, so if the fingerprint detection function can be used Adding to the outside of the smart device, it is easy to maintain and provides a large-scale fingerprint detection area, which will be a major improvement.

Therefore, the present invention proposes a protective case for optical sensing to effectively solve the above problems. The specific architecture and implementation will be described in detail as follows:

The main purpose of the present invention is to provide a protective casing for optical sensing, which is provided with a light source, a light guide plate and a photosensitive element on the upper and lower casings of the protective casing, and a smart device is installed between the upper and lower casings It can provide a smart device with a full-screen fingerprint detection function, not limited to the specific fingerprint recognition area of the smart device itself.

Another object of the present invention is to provide a protective casing for optical sensing. The upper and lower casings are easy to assemble. When the photosensitive element or the light source is damaged, the lower casing can be directly disassembled for replacement without repairing the smart device, which can save The time and cost required for maintenance.

To achieve the above object, the present invention provides an optical sensing protective case, which includes an upper case and a lower case. The smart device can be installed between the upper and lower cases. The upper and lower cases are interlocked with each other. A light guide plate, which is transparent and is provided on the upper case, a fingerprint sensing area for finger pressing on the light guide plate, and a first reflection on each side of the light guide plate Part and a second reflection part; a light source, provided on the lower casing, provides at least one optical signal, the optical signal is introduced into the light guide plate through the first reflection part, and passes the internal total reflection effect in the light guide plate Transmission, and then exported through the second reflection part; a signal amplifier, located on the lower case, below the second reflection part, receiving the optical signal derived from the second reflection part, and amplifying the optical signal and exporting And a photosensitive element, which is provided on the lower case and connected with the signal of the smart device, receives the optical signal derived from the signal amplifier, processes the optical signal into a fingerprint image and transmits it to the smart device.

According to an embodiment of the present invention, an upper surface of the light guide plate is covered by the upper casing, and a region where the upper surface is not covered is the fingerprint sensing area.

According to an embodiment of the invention, the light guide plate is disposed above a display screen of the smart device.

According to an embodiment of the present invention, the lower edge of the upper casing is provided with at least a first connection portion, and the upper edge of the lower casing is provided with at least a second connection portion, the first connection portion is connected to the second The upper part and the lower case are joined together.

According to an embodiment of the present invention, the photosensitive element is connected to a slot of the smart device through a signal line to transmit the optical signal to the smart device.

According to an embodiment of the invention, the light source is a collimated light source or a non-collimated light source. The collimated light source is a laser, a vertical resonant cavity surface laser (VCSEL), or a combination of a non-collimated light source and a secondary optical element.

As mentioned above, the secondary optical element is selected from a parabolic surface condenser, a compound parabolic condenser (CPC), a lens, a lens, a Fresnel lens, and a combination thereof.

According to an embodiment of the invention, the wavelength of the optical signal is between 380 and 1400 nanometers (nm).

According to an embodiment of the invention, the first reflecting portion, the second reflecting portion and the light guide plate are integrally formed.

According to an embodiment of the present invention, the first reflecting portion and the second reflecting portion are independent reflecting elements outside the light guide plate.

According to an embodiment of the present invention, a coating film is formed on the surface of the light guide plate, the coating film can penetrate a visible light, and the light in the remaining wavelength band is reflected.

According to an embodiment of the present invention, a lens, a Prism film, an angular filter, a polarizing beam splitter prism (PBS), and a beam splitter are further included between the photosensitive element and the signal amplifier BS) or a combination thereof.

According to an embodiment of the present invention, the angle filter is a vertical or tilt type grating filter.

According to an embodiment of the invention, the grating filter is a single-layer structure composed of a plurality of first material films spaced apart, or a single-layer structure composed of a plurality of first material films spaced apart from a plurality of second material films.

According to an embodiment of the present invention, the fingerprint sensing area further includes an activation area, and the finger is pressed in the activation area to activate the display screen of the smart device, which can prevent the user from accidentally touching but immediately unlocking the smart device When the situation occurs, the division of the activated area and the non-activated area can be determined by the screen touch function.

According to an embodiment of the present invention, the smart device may be a smart phone, a tablet computer, or a notebook computer.

The invention provides an optical sensing protective case, which is applied in a smart device. By optically sensing the position pressed by a finger and converting it into a fingerprint image, a smart device that does not have a fingerprint sensing function is provided with a fingerprint sensing function.

Please refer to Figures 1 and 2 at the same time, which are respectively a perspective view and an exploded view of an embodiment of the optical sensing protective case of the present invention equipped with a smart device, as shown in the figure, the optical sensing protective case 10 of the present invention Including an upper casing 12 and a lower casing 14, the smart device 30 can be installed between the upper casing 12 and the lower casing 14, the lower edge of the upper casing 12 is interlocked with the upper edge of the lower casing 14 Then, the upper casing 12 and the lower casing 14 can be combined into one body; a light guide plate 16 is provided on the upper casing 12 and is transparent, which is close to the display screen of the smart device 30 relative to the smart device 30 One side, so you can see the image displayed on the display screen through the transparent light guide plate 16, the fingerprint guide area is provided with a fingerprint sensing area for finger pressing, and a first Reflecting portion 162 and a second reflecting portion 164; a light source 18, a signal amplifier 19 and a photosensitive element 20 are provided on the lower casing 14, which are respectively disposed at the two ends of the lower casing 14 and can be front and rear ends or left and right At both ends, the light source 18 provides at least one optical signal. The optical signal is introduced into the light guide plate 16 through the first reflection portion 162, and transmitted through the total internal reflection (TIR) effect in the light guide plate 16, and then through the second The reflection part 164 is exported to the signal amplifier 19. The signal amplifier 19 is disposed on the lower case 14 and below the second reflection part 164. It can be in the form of a mirror to amplify the waveform of the optical signal to improve the signal definition The photosensitive element 20 and the smart device 30 are connected in a wired or wireless manner. After receiving the optical signal derived from the signal amplifier 19, the photosensitive element 20 processes the optical signal into a fingerprint image and sends it to the smart device 30. This smart device 30 can be a smartphone, tablet or laptop.

In the embodiment of the present invention, the light source 18 is a collimated light source or a non-collimated light source. The collimated light source is a laser, a vertical resonant cavity surface laser (VCSEL), or a combination of a non-collimated light source and a secondary optical element. Wherein, the secondary optical element is selected from parabolic surface (Parabolic surface) condenser, compound parabolic condenser (CPC), lens, prism, Fresnel lens (Fresnel lens) and combinations thereof. The photosensitive element 20 may be a charge-coupled device (CCD) or a complementary metal oxide semiconductor active pixel sensor (CMOS Active pixel sensor).

Please refer to FIG. 3, which is a cross-sectional view of an embodiment of the optical sensing protective case of the present invention when a smart device is installed. In this embodiment, the upper surface of the light guide plate 16 is covered by the upper casing 12, and the area on the upper surface that is not covered by the upper casing 12 is the fingerprint sensing area, which can be pressed by the user with a finger. In the embodiment of the present invention, the first reflecting portion 162, the second reflecting portion 164 and the light guide plate 16 are integrally formed, or may be provided separately. The first reflecting portion 162 and the second reflecting portion 164 are independent of the guide The reflective elements outside the light plate 16, such as mirrors. In this embodiment, the photosensitive element 20 is connected to a slot 32 of the smart device 30 via a signal line 34 to transmit the signal to the smart device 30.

The lower edge of the upper casing 12 is provided with at least one first connection portion 122, and the upper edge of the lower casing 14 is provided with at least one second connection portion 142. The first connection portion 122 is buckled with the second connection portion 142, The upper and lower casings 12, 14 are joined together. In particular, the first connecting portion 122 can be a full circle around the lower edge of the upper casing 12, or it can be arranged only on the left, right, top, bottom, or any position. Similarly, the second connecting portion 142 may be a full circle around the upper edge of the lower housing 14, or may be provided only on the left, right, top, or under any position corresponding to the first connecting portion 122, so that the first connecting portion 122 and the first connecting portion 122 The two connecting portions 142 can be engaged with each other.

It can be clearly seen from FIG. 3 that the light source 18 is disposed below the first reflecting portion 162 and upwardly projects the optical signal into the first reflecting portion 162; the first reflecting portion 162 reflects the optical signal in a total reflection manner It is transmitted to the second reflection part 164 in the light guide plate 16. The signal amplifier 19 is directly under the second reflection part 164. The optical signal is reflected to the photosensitive element 20 through the second reflection part 164 and the signal amplifier 19. Transmission path. When the user presses the surface of the light guide plate 16 with his finger, it will cause the destruction of the total reflection of the optical signal in the light guide plate 16, and the photosensitive element 20 can detect the waveform change of the optical signal and process it as a fingerprint image to achieve the fingerprint The purpose of detection.

Among them, the wavelength of the optical signal is between 380 to 1400 nanometers (nm), and in practical applications, it can be divided into the visible light section (380 to 780 nm) and the near infrared section (780 to 1400 nm).

A coating is formed on the surface of the light guide plate 16, the coating can penetrate a visible light, and the light in the remaining wave band is reflected, so the user can see the screen display, but the optical signal is still transmitted in the light guide plate 16 by total reflection .

In addition, since the optical sensing protective case of the present invention provides full-screen fingerprint detection, the entire light guide plate 16 can be a fingerprint sensing area for detecting a user's fingerprint. Therefore, in order to avoid the user simply holding the smart device in hand There is no need to use it, but the situation occurs when the finger is pressed on the light guide plate 16 to unlock and open the display screen. Therefore, in one embodiment of the present invention, a startup area can be set on the light guide plate 16 (not shown) ), the position and area of the activation area can be determined by the screen touch function, and the display screen will only be turned on when the finger is pressed in the activation area. , Such as the middle area.

FIG. 4A and FIG. 4B are schematic diagrams of embodiments of different fastening methods of the upper and lower shells in the optical sensing protective shell of the present invention. In FIG. 4A, the first connection part 122 of the upper case 12 and the second connection part 142 of the lower case 14 are barbed and can be fastened to each other; in FIG. 4B, the second connection part of the lower case 14 142 is concave, and the first connection portion 122 of the upper housing 12 is convex. The first connection portion 122 can be inserted into the second connection portion 142 and buckled. However, these two embodiments are not limited by the present invention, and other fastening methods as long as the upper and lower housings 12, 14 can be combined together, should be included in the present invention.

In the embodiment of the present invention, a light-transmitting element, such as a lens, Prism film, angular filter, polarizing beam splitter prism (PBS), is further included between the photosensitive element 20 and the signal amplifier 19 Beamsplitter (BS) or a combination thereof, FIG. 5A is a schematic diagram of an embodiment in which a lens 22 is provided on the photosensitive element 20, and FIG. 5B is a schematic diagram of an embodiment in which a thin film 24 is provided on the photosensitive element 20, FIG. 5C FIG. 5D is a schematic diagram of an embodiment in which a combination of a thin film 24 and an angle filter 26 is disposed on the photosensitive element 20.

Among them, the angle filter 26 shown in FIG. 5C is a vertical type grating filter, but it may also be a tilt type grating filter (not shown). In addition, the grating filter may be a single-layer structure composed of a plurality of first material films spaced apart, or a single-layer structure composed of a plurality of first material films spaced apart from a plurality of second material films. If the light source is a non-collimated light source, the optical signal without collimation is transmitted in the light guide plate, and then a high-order angle filter is arranged on the photosensitive element, which can also achieve the purpose of fingerprint imaging.

In summary, the protective casing for optical sensing provided by the present invention is to arrange the light guide plate on the upper casing of the protective casing, and the light source and the photosensitive element are arranged on both ends of the lower casing of the protective casing. After the body is combined, the smart device is installed between the upper and lower shells. The transparent light guide plate allows the user to still see the screen display on the smart device, but at the same time, the light guide plate provides a full-screen fingerprint Detection function, the user’s finger presses any position exposed on the light guide plate to allow the photosensitive element to obtain the optical signal and convert it into a fingerprint image. In this way, the fingerprint detection function or the full-screen fingerprint recognition is not available After the functional smart device is installed with the optical sensing protective shell of the present invention, it can directly have the function of full-screen fingerprint detection. In addition, if the light source or the photosensitive element is damaged, the lower case can be directly replaced without disassembling and repairing the smart device, which greatly saves maintenance costs.

The above are only preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes or modifications based on the features and spirit described in the application scope of the present invention should be included in the patent application scope of the present invention.

10‧‧‧Protection case for optical sensing 12‧‧‧Upper case 122‧‧‧First connection part 14‧‧‧Lower case 142‧‧‧Second connection part 16‧‧‧‧Light guide plate 162‧‧‧ First reflection part 164‧‧‧ Second reflection part 18‧‧‧Light source 19‧‧‧Signal amplifier 20‧‧‧Photosensitive element 22‧‧‧Lens 24‧‧‧Leng film 26‧‧‧Angle filter 30‧ ‧‧Smart device 32‧‧‧Slot 34‧‧‧Signal cable

FIG. 1 is a perspective view of an embodiment of the optical sensing protective case of the present invention when a smart device is installed. Figure 2 is an exploded view of the embodiment of Figure 1. FIG. 3 is a cross-sectional view of an embodiment of the optical sensing protective case of the present invention when a smart device is installed. FIG. 4A and FIG. 4B are schematic diagrams of embodiments of different fastening methods of the upper and lower shells in the optical sensing protective shell of the present invention. FIG. 5A is a schematic diagram of an embodiment of a lens disposed on a photosensitive element in a protective case for optical sensing of the present invention. FIG. 5B is a schematic diagram of an embodiment in which a thin film of thin films is disposed on a photosensitive element in a protective case for optical sensing of the present invention. FIG. 5C is a schematic diagram of an embodiment in which an angle filter is disposed on the photosensitive element in the optical sensing protective case of the present invention. FIG. 5D is a schematic diagram of an embodiment in which a thin film and an angle filter are disposed on a photosensitive element in a protective case for optical sensing of the present invention.

10‧‧‧ Optical sensing protective shell

12‧‧‧Upper case

122‧‧‧First connection

14‧‧‧Lower case

142‧‧‧Second connection

16‧‧‧Light guide plate

162‧‧‧First Reflection Department

164‧‧‧Second Reflection Department

18‧‧‧Light source

19‧‧‧Signal amplifier

20‧‧‧Photosensitive element

30‧‧‧Smart device

32‧‧‧slot

34‧‧‧Signal line

Claims (18)

An optical sensing protective case, which is applied to a smart device, includes: an upper case and a lower case, the smart device can be installed between the upper and lower cases, and the upper and lower cases are Combined with each other; a light guide plate, which is transparent, is provided on the upper case, the light guide plate is provided with a fingerprint sensing area which can be pressed by fingers, and two sides of the light guide plate are respectively provided with a first A reflecting part and a second reflecting part; a light source, provided on the lower casing, provides at least one optical signal, the optical signal is introduced into the light guide plate through the first reflecting part, and passes through the inner light guide plate in the light guide plate The reflection effect is transmitted, and then derived through the second reflection part; a signal amplifier, located on the lower case and below the second reflection part, receives the optical signal derived from the second reflection part and amplifies the optical signal After the export; and a photosensitive element, which is provided on the lower case and connected with the signal of the smart device, receives the optical signal derived from the signal amplifier, processes the optical signal into a fingerprint image and transmits it to the smart device. The protective cover for optical sensing according to claim 1, wherein an upper surface of the light guide plate is covered by the upper housing, and a region where the upper surface is not covered is the fingerprint sensing area. The optical sensing protective case according to claim 1, wherein the light guide plate is disposed above a display screen of the smart device. The optical sensing protective case according to claim 1, wherein the lower edge of the upper casing is provided with at least a first connection portion, and the upper edge of the lower casing is provided with at least a second connection portion, the first The connecting portion is buckled with the second connecting portion to join the upper and lower housings together. The protective casing for optical sensing according to claim 1, wherein the photosensitive element is connected to a slot of the smart device through a signal line to transmit the optical signal to the smart device. The optical sensing protective case according to claim 1, wherein the light source is a collimated light source or a non-collimated light source. The protective casing for optical sensing according to claim 6, wherein the collimated light source is a laser, a vertical resonant cavity surface laser (VCSEL), or a combination of a non-collimated light source and a secondary optical element. The protective casing for optical sensing according to claim 7, wherein the secondary optical element is selected from a parabolic surface condenser, a compound parabolic condenser (CPC), a lens, a lens, a Fresnel lens And combinations. The optical sensing protective case as described in claim 1, wherein the wavelength of the optical signal is between 380 and 1400 nanometers (nm). The optical sensing protective case according to claim 1, wherein the first reflection part, the second reflection part and the light guide plate are integrally formed. The optical sensing protective case as claimed in claim 1, wherein the first reflection part and the second reflection part are independent reflection elements outside the light guide plate. The protective cover for optical sensing according to claim 1, wherein a coating film is formed on the surface of the light guide plate, the coating film can penetrate a visible light, and the light in the remaining wavelength band is reflected. The protective casing for optical sensing according to claim 1, wherein a lens, a Prism film, an angular filter, and a polarization beam splitter are further included between the photosensitive element and the signal amplifier Prism (PBS), beam splitter (BS) or a combination thereof. The protective casing for optical sensing according to claim 13, wherein the angle filter is a vertical type or a tilt type grating filter. The protective casing for optical sensing as claimed in claim 14, wherein the grating filter is a single-layer structure composed of a plurality of first material films spaced apart. The protective casing for optical sensing according to claim 14, wherein the grating filter is a single-layer structure composed of a plurality of first material films and a plurality of second material films spaced apart. The optical sensing protective case according to claim 1, wherein the fingerprint sensing area further includes an activation area, the finger is pressed in the activation area to activate the display screen of the smart device, and the position of the activation area and The size of the area can be determined by the screen touch function. The optical sensing protective case according to claim 1, wherein the smart device may be a smart phone, a tablet computer or a notebook computer.

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