Apple Invents Water Detecting Pressure Sensors & Advances Smartglasses with Adjustable Optical Layers
Today the US Patent & Trademark Office published patent applications from Apple that relate to water detecting pressure sensors and adjustable optic layers that could be used in future smartglasses.
Apple uses many kinds of pressure sensors in their iDevices such as the iPhone and Apple Watch that could enable health and fitness features. Pressure sensors can also be used to measure pressure in a gas or liquid and measure elevation, motion and more. Keeping water away from these sensors are important for the health of Apple's mobile devices.
In Apple's patent background they note that the micro-electro-mechanical system (MEMS) type pressure sensors used in smart phones or smart watches are generally capacitive-type pressure sensors. Pressure sensors using interim gel have been widely used in the microelectronic devices, but the gel can be susceptible to environmental contaminations and water occlusion. There is a need for pressure sensors that can detect presence of a water droplet on the gel.
Water Detecting Pressure Sensors
Apple's patent relates generally to sensor technology, and more particularly, to a water detecting pressure sensor. More specifically, Apple's patent covers a water detecting miniature pressure-sensing device (e.g., having dimensions in the order of a few millimeters).
The pressure-sensing device includes one or more electrodes for detecting a water droplet and, in some implementations, includes one or more heating elements for causing the water droplet to evaporate.
The disclosed water detecting pressure-sensing device includes a metal housing, a pressure sensor, a protection medium and one or more electrodes. The pressure sensor can be a capacitive or a piezo-resistive pressure sensor. The metal housing includes a cavity and the pressure sensor is disposed on a die inside the cavity.
The pressure sensor can generate a signal in response to a pressure variation. The protection medium at least partially fills the cavity and covers the die. The electrodes can be disposed on the die to detect presence of a water droplet on the protection medium.
In one or more implementations, the electrodes are four corner electrodes and are made of an electrically conductive material that is resistive to environmental chemicals. The four corner electrodes are coupled to form a joint capacitance or four different capacitances with the metal housing.
Apple's patent FIGS. 1A through 1C below are diagrams illustrating different views of an example water detecting pressure-sensing device. The three examples of 100A, 100B and 100C can be a miniature gel-filled pressure-sensing device that can detect a water droplet 150 on the gel.
Apple's patent application 20190383688 that was published today by the U.S. Patent Office was filed back in Q2 2018. Considering that this is a patent application, the timing of such a product to market is unknown at this time.
Electronic Devices Having Electrically Adjustable Optical Layers
Last month patently Apple posted a patent report titled "Head Mounted Display with Infrared Transparent One-Way Mirror." It was a foundational patent for this type of work on optical layers.
The report noted that "Apple's invention covered glasses or a headset that may include an infrared-transparent one-way mirror. The infrared-transparent one-way mirror may be formed by a layer of material that is supported by head-mounted support structure or other support structure. The optical components may operate through the layer of material while being hidden from view by the reflective appearance of the infrared-transparent one way mirror."
Today Apple is advancing their work on optical layers with an invention that adds the ability for a user in the future to electrically adjust the optical layers of a pair of smartglasses (or other devices) to varying degrees so as to lighten or darken the face of the device, glasses or frame of a head-mounted display device so that components like a camera are hidden from the public's view.
Apple's patent FIG. 1 below is a schematic diagram of an illustrative electronic device with optical components and electrically adjustable optical layers.
In respect to figure 2 above, Apple's headset shown as device #10 above may have one or more electrically adjustable optical devices such as electrically adjustable optical layer #8. Layer #8 may be adjusted to operate in different modes.
For example, in different modes of operation, layer #8 may exhibit different light transmission values (e.g., a high transmission value of at least 80% or at least 90% or a low transmission value of less than 40%, less than 20%, or less than 10%), different colors (e.g., non-neutral colors such as blue, red, green, blue-black, etc.), different neutral colors (white, black, gray, etc.), different reflectivities (e.g., a low reflectivity of less than 40%, less than 20%, or less than 10% or a high reflectively of more than 60%, more than 80%, or more than 90%), different light absorption values (and/or different light absorption spectral shapes), different amounts of haze, and/or other properties that vary the appearance and/or light transmission, absorption, reflection, color, and/or haze of layer 8.
Electrically adjustable optical layer #8 may be formed from a liquid crystal device such as a guest host liquid crystal device, a liquid crystal device with polarizers, or a cholesteric liquid crystal device, an electrochromic device, a suspended particle device, an electrophoretic device, an electrowetting device, an adjustable color filter, and/or other adjustable devices that exhibit adjustable optical properties such as haze, color, light reflection, light absorption, and/or light transmission.
For more details on this, review patent 20190384062 here.