The invention relates to an optical proximity sensor that prevents a vertical-cavity surface-emitting laser thereof from interfering with a proximity sensor thereof and that maximizes a detection angle of ambient lights for the device.
Smart mobile devices such as smartphones usually have an ambient light sensor (ALS) for ambient light detection to adjust brightness of the touchscreen for energy-saving; such devices also have a proximity sensor (PS) and a light emitter for proximity detection to automatically close the touchscreen in case of inadvertent operations when a user's face is close to the touchscreen during a phone call. The ALS and PS are both applications of light detection and therefore can be integrated into one package with the light emitter for less space for installation, less manufacturing materials, and for combined arrangement for circuits. The ALS and PS are usually disposed at a side a display panel of a smart mobile device, and ALS detects an angle wider than PS does. However, when the ALS and PS are closely disposed and encapsulated within a package, the detection angle of ALS will be restricted by the detection angle of PS.
As shown in
A PS structure 31 of iPhone 7 Plus is illustrated in
The PS structure 31 is installed on an iPhone 7 Plus 30 corresponding to the opening 33 under a glass layer 34. However, when the light emitting device 317 emits lights at an angle θa2, a first optical noise is produced by lights emitted to an object O and reflected by a first surface 341 of the glass layer 34 at a first reflection angle θn1 and a second optical noise is produced by lights emitted to the object O and reflected by a second surface 342 of the glass layer 34 at a second reflection angle θn2. In other words, there are still interferences with operation of detection.
Another PS structure 41 is shown in
On the other hand, both iPhone 6 Plus and 7 Plus has an ALS structure 42 installed thereon as presented in
Although structures with separate PS and ALS detect better, they cost higher prime costs as well. Also, such structures require two openings on the device for corresponding explosion for detection. Therefore, it is desirable to integrate PS and ALS structures while keeps the same effectiveness of detection.
It is a primary objective of the present invention to provide a complex optical proximity sensor with a self-integrated barrier that includes an ambient lights detection chip as an independent ambient lights sensor (ALS) and a proximity sensor structure composed of a vertical-cavity surface-emitting laser (VCSEL) and a proximity sensor (PS). The ALS being the barrier prevents the VCSEL from interfering with the PS and maximizes a detection angle of ambient lights.
In order to achieve the objectives above, the complex optical proximity sensor to be installed in a mobile device under an opening hole comprises a substrate; an application-specific integrated circuit (ASIC) chip coupled to the substrate and connected to a proximity sensor thereon; a vertical-cavity surface-emitting laser coupled to the substrate in linear alignment with the proximity sensor, said vertical-cavity surface-emitting laser emitting laser beam with a first wavelength and a first energy received by the proximity sensor; an ambient lights detection chip manufactured separately and then coupled to the application-specific integrated circuit chip, said ambient lights detection chip receiving lights with a second wavelength and a second energy, wherein the ambient lights detection chip stands a pre-determined height independently on the application-specific integrated circuit chip and is disposed between the vertical-cavity surface-emitting laser and the proximity sensor in linear alignment, forming a self-integrated barrier in-between the vertical-cavity surface-emitting laser and the proximity sensor; and a package body encapsulating the application-specific integrated circuit chip, proximity sensor, vertical-cavity surface-emitting laser, and ambient lights detection chip on the substrate, said package body including an oblong hole in a middle section at a top thereof to expose the ambient lights detection chip.
Advantageously, the first wavelength is 940 nm and the second wavelength is 550 nm; the package body is a cap.
In addition, the package body may include a transparent package filling up the oblong hole and covering the application-specific integrated circuit chip, proximity sensor, vertical-cavity surface-emitting laser, and ambient lights detection chip within the package body; the transparent package may be a lens.
Furthermore, the ambient lights detection chip detects ambient lights, RGB lights, or UV lights. The substrate is either a ceramic substrate or a PCB for the application-specific integrated circuit chip and the vertical-cavity surface emitting laser to be connected by coupling, and the application-specific integrated circuit chip has a plurality of first connect points coupled to a plurality of corresponding second connect points on the ambient lights detection chip. The substrate may further include a plurality of bond pads arranged under a bottom thereof to be coupled to the application-specific integrated circuit chip and the vertical-cavity surface emitting laser, making the complex optical proximity sensor a surface-mount device.
Also, the proximity sensor is connected to the application-specific integrated circuit chip either by coupling or installation.
The oblong hole has a length and a width arranged less than a diameter of the opening hole and the ambient lights detection chip is exposed at a center of the oblong hole as the self-integrated barrier, displaying a symmetric detection angle about the ambient lights detection chip.
As stated above, the ambient light detection chip stands independently on the ASIC chip with a pre-determined height to form a self-integrated barrier between the VCSEL and the PS for prevention from interferences with the PS and for maximizing a detection angle for ambient lights. In addition, the VCSEL and the ambient lights detection chip are set to receive lights with different wavelength and different energies to further ensure prevention from interferences with the PS.
Referring to
The substrate 51 is a ceramic substrate or a PCB. The ASIC chip 52 is coupled to the substrate 51 via an electric wire and has a proximity sensor 521 connected thereto. In this embodiment, the proximity sensor 521 is either coupled to or installed on the ASIC chip 52.
The vertical-cavity surface-emitting laser (VCSEL) 53 is coupled to the substrate 51 via an electric wire in linear alignment with the proximity sensor 521. The VCSEL 53 emits laser beam with a first wavelength and a first energy received by the proximity sensor 521. The laser beam is invisible to human eyes and can be divided into short-wavelength infrared ranging 850 nm-950 nm and long-wavelength infrared ranging 1300 nm-1550 nm. In another embodiment, the VCSEL 53 is coupled to the ASIC chip 52 and operates the same.
The ambient light detection chip 54 is separately manufactured and then coupled to the ASIC chip 52. The ambient light detection chip 54 stands a pre-determined height independently on the ASIC chip 52 and is disposed between the VCSEL 53 and the proximity sensor 521 in linear alignment along an X-axis X as shown in
Furthermore, the ASIC chip 52 s detection chip includes a plurality of first connect points 522 coupled to a plurality of corresponding second connect points 541 on the ambient lights detection chip 54 for electric connection. Besides, the substrate 51 has electric wires therein for the ASIC chip 52 and the VCSEL 53 to be connected by coupling. With reference to
The package body 55 encapsulates the ASIC chip 52, proximity sensor 521, VCSEL 53, and ambient lights detection chip 54 on the substrate 51. The package body 55 further includes an oblong hole 551 in a middle section at a top thereof to expose the ambient lights detection chip 54 as shown in
In
The chart below further illustrates comparisons of ALS and PS structures between the present invention, iPhone 4, iPhone 6 Plus, and iPhone 7 Plus.
From the chart above we can learn that whether the ALS structure and the PS structure interferes with each other is an important factor in smartphones, considering the development in a later structure B and C installed on iPhone 6 Plus and 7 Plus. Even with higher prime costs, such structure is still used to replace previous structure A installed on iPhone 4. On the other hand, the present invention has ALS and PS structures integrated into a complex structure module without extra arrangement of a barrier to achieve a small volume of the complex optical proximity sensor 50, consuming less space required for installation and less prime costs for manufactures. Meanwhile, structures of the present invention also prevents from interferences with ALS and PS structures during operation and provides a comparatively wider angle for detection with the design of having one circular opening hole 61 on the smartphone 60 and having the ALS structure disposed right under the opening hole 61.
Number | Date | Country | Kind |
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106112059 | Apr 2017 | TW | national |