Apple patents panel-type acoustic system for portable devices, woven displays
Apple on Tuesday was granted a pair of patents for maximizing space in portable devices, one covering a panel acoustic system that provides high quality sound in thin enclosures and another detailing woven displays for Apple Watch.
As awarded by the U.S. Patent and Trademark Office, Apple's U.S. Patent No. 9,525,943 for a "Mechanically actuated panel acoustic system" details an audio solution that creates sound through the direct vibration of sub-panels in a substantially flat arrangement.
In basic terms, traditional dynamic speaker systems incorporate large diaphragms, usually conical in shape, that include an attached voice coil wire. The voice coil is positioned in a frame adjacent to a large permanent magnet.
When electrical current is applied to the voice coil, it creates a magnetic field that interacts with the permanent magnet to push and pull the attached diaphragm. This oscillating action, interpreted by onboard audio signal conversion components, creates waves of pressure in the air surrounding the diaphragm, thereby creating sound.
Micro speakers like those deployed in Apple's own products operate in much the same way, but on a smaller scale. Voice coils integrated with panel-like diaphragms and small permanent magnets comprise a largely self-contained system, though Apple has been looking for ways to maximize volume and minimize distortion with increasingly large back volumes.
Turning to Apple's patent, the panel-style speaker theme is taken to a new level. As described, the system is actually a large panel divided into smaller sub-panels designed to act as individual diaphragms. These panels sit above a back air volume, or cell, while voice coil motors and embedded permanent magnets provide the movement needed to generate sound.
Importantly, the panel speaker's backing frame divides and defines the sub-panels, giving each a different resonant frequency. The backing frames are supported by mid-plates connected to the front panel to reduce errant vibrations.
Since the individual sub-panels have dedicated voice coils, an onboard audio converter can send appropriate signals to distinct assemblies, thus allowing for highly accurate acoustics.
Alternative embodiments allow for designs that mount the actuator magnet to the back panel while the mid-plate holds the active voice coil. Other examples do away with the mid-plate altogether, instead securing the magnet directly to the front panel or abutting structure. A separate embodiment calls for sub-panels of the front panel to operate as diaphragms, rather than a division of the back panel.
In theory, Apple's sub-panel mechanism can be configured to reproduce high-definition sound in a relatively shallow displacement installation, suitable for thin devices like iPad and MacBook.
Interestingly, the design is somewhat similar to the speaker layout introduced with Apple's 12.9-inch iPad Pro. The iPad, however, currently employs four "self-balancing" micro speaker drivers that feed carbon fiber-capped resonance chambers, that is the carbon fiber elements are not themselves diaphragms.
Whether Apple plans to incorporate its panel speaker technology in a future product is unknown, though the company has a penchant for decreasing device footprints with each successive generation. A true panel-type speaker mechanism could go a long way in maximizing internal space, for example by nixing bulky micro drivers.
Apple's panel speaker patent was first filed for in November 2014 and credits Matthew A. Donarski, Daniel K. Boothe, Justin D. Crosby and Mitchell R. Lerner as its inventors.
A second patent grant, No. 9,521,885 for a "Woven display," details a method by which light-transmissive materials are interwoven into conventional textiles. When connected to LEDs or another light source, these light pipe fibers can render computer generated imagery, useful for secondary displays on wearable devices like Apple Watch.
As AppleInsider noted when the patent surfaced as an application last December, Apple's invention lays down light transmissive fibers like glass, polymers and nylon alongside opaque fibers to form a precise pattern. Advanced machining techniques and tools, for example three-dimensional knitting equipment, makes the design of such complex spatial designs a possibility.
Alternatively, light-transmissive sections of the hybrid woven band might be obscured or otherwise made opaque during the finishing process by applying a light-blocking substance.
Connecting the light fiber leads to a light source on the host device yields a workable, albeit low resolution, display capable of presenting users with readable information. Depending on the stitch, the woven band might display multicolor symbols or even alphanumeric characters to convey system alerts or simple notifications.
Apple's woven display patent was first filed for in May 2014 and credits Douglas J. Weber and Teodor Dabov as its inventors.
As awarded by the U.S. Patent and Trademark Office, Apple's U.S. Patent No. 9,525,943 for a "Mechanically actuated panel acoustic system" details an audio solution that creates sound through the direct vibration of sub-panels in a substantially flat arrangement.
In basic terms, traditional dynamic speaker systems incorporate large diaphragms, usually conical in shape, that include an attached voice coil wire. The voice coil is positioned in a frame adjacent to a large permanent magnet.
When electrical current is applied to the voice coil, it creates a magnetic field that interacts with the permanent magnet to push and pull the attached diaphragm. This oscillating action, interpreted by onboard audio signal conversion components, creates waves of pressure in the air surrounding the diaphragm, thereby creating sound.
Micro speakers like those deployed in Apple's own products operate in much the same way, but on a smaller scale. Voice coils integrated with panel-like diaphragms and small permanent magnets comprise a largely self-contained system, though Apple has been looking for ways to maximize volume and minimize distortion with increasingly large back volumes.
Turning to Apple's patent, the panel-style speaker theme is taken to a new level. As described, the system is actually a large panel divided into smaller sub-panels designed to act as individual diaphragms. These panels sit above a back air volume, or cell, while voice coil motors and embedded permanent magnets provide the movement needed to generate sound.
Importantly, the panel speaker's backing frame divides and defines the sub-panels, giving each a different resonant frequency. The backing frames are supported by mid-plates connected to the front panel to reduce errant vibrations.
Since the individual sub-panels have dedicated voice coils, an onboard audio converter can send appropriate signals to distinct assemblies, thus allowing for highly accurate acoustics.
Alternative embodiments allow for designs that mount the actuator magnet to the back panel while the mid-plate holds the active voice coil. Other examples do away with the mid-plate altogether, instead securing the magnet directly to the front panel or abutting structure. A separate embodiment calls for sub-panels of the front panel to operate as diaphragms, rather than a division of the back panel.
In theory, Apple's sub-panel mechanism can be configured to reproduce high-definition sound in a relatively shallow displacement installation, suitable for thin devices like iPad and MacBook.
Interestingly, the design is somewhat similar to the speaker layout introduced with Apple's 12.9-inch iPad Pro. The iPad, however, currently employs four "self-balancing" micro speaker drivers that feed carbon fiber-capped resonance chambers, that is the carbon fiber elements are not themselves diaphragms.
Whether Apple plans to incorporate its panel speaker technology in a future product is unknown, though the company has a penchant for decreasing device footprints with each successive generation. A true panel-type speaker mechanism could go a long way in maximizing internal space, for example by nixing bulky micro drivers.
Apple's panel speaker patent was first filed for in November 2014 and credits Matthew A. Donarski, Daniel K. Boothe, Justin D. Crosby and Mitchell R. Lerner as its inventors.
A second patent grant, No. 9,521,885 for a "Woven display," details a method by which light-transmissive materials are interwoven into conventional textiles. When connected to LEDs or another light source, these light pipe fibers can render computer generated imagery, useful for secondary displays on wearable devices like Apple Watch.
As AppleInsider noted when the patent surfaced as an application last December, Apple's invention lays down light transmissive fibers like glass, polymers and nylon alongside opaque fibers to form a precise pattern. Advanced machining techniques and tools, for example three-dimensional knitting equipment, makes the design of such complex spatial designs a possibility.
Alternatively, light-transmissive sections of the hybrid woven band might be obscured or otherwise made opaque during the finishing process by applying a light-blocking substance.
Connecting the light fiber leads to a light source on the host device yields a workable, albeit low resolution, display capable of presenting users with readable information. Depending on the stitch, the woven band might display multicolor symbols or even alphanumeric characters to convey system alerts or simple notifications.
Apple's woven display patent was first filed for in May 2014 and credits Douglas J. Weber and Teodor Dabov as its inventors.
Comments
that were briefly popular in the...seventies? eighties?
Or perhaps they still are. I'm neither an audiophile, nor an engineer - electrical, acoustical, or otherwise,
so if I've said something unspeakably ignorant about speaker technology, please school me!
There are a few big problems with electrostatic speakers for this application. Perhaps most importantly, electrostatics need extremely high voltages to work. Some electrostatic headphones have been made which "only" used 800v. Larger panels typically use 3kv or more. The current is very low, so overall power consumption isn't bad, but getting voltages that high involves big transformers. The other limitation is electrostatics typically involve two "stators" with the membrane between them. The stators have to be far enough apart (and far enough from the membrane) to prevent arcing from the high voltages involved.
This patent seems much better suited to orthodynamic drivers (also called "planar magnetic"). Where traditional dynamic drivers have a voice coil as discussed here, orthodynamic drivers flatten the voice coil out into a plane. They typically use very unusual wire patterns, and the wires do not overlap. They also require a complicated layout of magnets to act against.
A major advantage of electrostatic speakers over ordinary dynamic speakers (with a voice coil) is that they apply the motive force very evenly across the surface area of the driver. Orthodynamic drivers try to do the same thing, but with electromagnetic forces instead of electrostatic. Electrostatics are frequently called "massless drivers" because the membrane has about as much mass as an inch of air. Orthodynamics are heavier, so they don't respond quite as quickly, but they're still fast enough for audio frequencies and they don't require the high voltages or the same thickness as electrostatics.
I did think power would be an issue, so I suppose the separation issue is irrelevant
unless your iPhone comes with something the size of a car battery or more!
This would seem to run counter to current trends...
Do an image search for orthodynamic or planar magnetic headphone drivers some time. They look really neat.