Apple Reveals Secrets Relating to Manufacturing Processes
On September 20, 2012, the US Patent & Trademark Office published a series of 17 patent applications from Apple. In this report we cover three patent applications relating to various manufacturing processes related to iDevices. In our recent report titled Apple's Leadership and Magic Shine Through we presented a segment covering Sir Jony Ive on the iPhone 5 and the many manufacturing processes associated with it. Jony takes such pride in his work that it shines through in every product. And so it's always fascinating to see new processes being revealed in patent filings. If you happen to appreciate the making of products, like I do, then I think that you'll enjoy this report and the links to each patent. In other IP news, Apple has been granted a registered trademark for VoicePass.
Patent One: Testing an Infrared Proximity Sensor
Apple's patent filing begins with some background. Apple states that a proximity sensor is a sensor that is able to detect the presence of nearby objects without any physical contact. One particular type of proximity sensor emits a beam of electromagnetic radiation in the infrared spectrum, and detects changes in the field or return signal. The object being sensed may be referred to as the proximity sensor's target. To test such a sensor, a target is selected that has sufficient reflection characteristics in the infrared spectrum used by the sensor. The target is then placed at different distances from the sensor, while measuring the output of the sensor. As the target is moved farther away, the output of the sensor drops. Typically, the sensor is tested at several different target distances, and if its output falls outside an expected range for each target distance, then the sensor may be deemed a failing unit.
While the proximity sensor has long had several applications, its relatively recent use in personal mobile communications devices such as cellular phones and smart phones that have a touch sensitive display screen presents a particularly difficult challenge for its high volume manufacture testing.
Smart phones such as the iPhone device by Apple Inc. use a proximity sensor to detect when the user has moved the device to their ear during a call, and on that basis may decide to disable any input from a touch screen to avoid inadvertent touch commands being entered due to contact with the user's cheek. Quality control may call for each specimen of such a smart phone device to be tested prior to sale. Since a relatively large number of such specimens may need to be released to end users over a short time interval, for example every day, a more efficient test methodology for testing the proximity sensor is needed.
New Way to Test Proximity Sensors
Apple's invention relates to enabling the testing of a proximity sensor without requiring a sensor target to be moved relative to the device under test, in order to check the response of the sensor to different target distances. A system for testing an infrared proximity sensor includes an infrared reflector that receives radiation transmitted from the proximity sensor, and an electronically modulated infrared transmissive (EMIRT) device that is positioned between the sensor and the reflector. A tester is coupled to control the EMIRT device for testing the sensor. The tester changes the infrared absorption characteristics of the EMIRT device, while the sensor is operating and the EMIRT device and the reflector remain in their fixed positions.
Output data from the sensor is collected while the sensor is operating (and the infrared absorption characteristics of the device are changing). The collected output data is compared to expected data to determine whether or not the proximity sensor has passed a target object distance test. As an example, the EMIRT device may include an array of liquid crystal elements that are controlled by the tester to achieve variable attenuation of the infrared radiation that is passing through the array. Such a system may be more cost effective and may be faster than a conventional proximity sensor test system in which the test target needs to be automatically moved to different distances.
Patent Credits: Apple's patent application 20120235029 was originally filed in Q1 2011 by the sole inventor Ching Tam.
Patent Two: Method and Apparatus for Producing Magnetic Attachment System
Apple's patent generally relates to magnets and methods and apparatuses for producing a magnetic attachment system. More particularly, the present embodiments describe magnets for use in releasable attachment techniques well suited for portable electronic devices.
Apple's filing states that magnets, which produce a magnetic field, are typically used to attract or repel another object. The magnetic field can produce a force that pulls on ferromagnetic materials, such as iron. The magnetic field produced by a magnet also attracts or repels other magnets.
Magnets can be used as an attachment mechanism for various objects. A common example is a refrigerator magnet that can be used to attach objects, such as paper, to a refrigerator. Magnets can also be used as an attachment means in place of mechanical fasteners in electronic devices, such as portable computing devices. Recent advances in portable computing includes the introduction of hand held electronic devices and computing platforms along the lines of the iPad tablet manufactured by Apple Inc. of Cupertino, Calif.
Patent Excerpts Relating to Apple's Manufacturing process
Typically, a manufacturing process for producing magnets begins with melting Rare Earth elements, such as, for example, neodymium, iron, and boron, to form an alloy. The melted neodymium iron boron (NdFeB) alloy then is then cooled, forming ingots of the alloy. The alloy ingots are then pulverized into small magnetic particles that are about several microns in size. The magnetic particles are then placed in a jig to press them into shape while a magnetic field is applied.
While the magnetic field is applied, the magnetic domains of the particles align with the magnetic field that is applied. The magnetic field can be applied using electromagnetic coils that are typically positioned normal to the surface of the pressing block. Thus, the resulting orientation of the magnetic field axis is generally normal to the surface of the pressed magnet. However, there can be a need to have a magnetic field axis that is at an angle or not normal to the surface of the magnet. There have been attempts to orient the magnetic field axis at an angle to the pressing block, but such attempts have been unsuccessful thus far, usually resulting in a fractured block.
Before the pressed magnet is released from the jig, a demagnetizing pulse is applied to demagnetize the magnet. The pressed particles are then heat treated in a sintering furnace to give the magnet its magnetic properties and to increase its density. The sintering process causes the pressed magnet to no longer have a flat or smooth outer surface and to shrink as the particles fuse together. The shrinking that occurs during the sintering process results in an uneven outer surface that can be unpredictable and often the shape of the magnet will not be to desired dimensions. Because the outer surface is unpredictable, it is also difficult to predict variations of the outer surface of the block relative to the magnetic field axis.
In order to achieve the required measurements of the magnets, the outer surface is then machined so that the surface is flat and to the desired dimensions. It should be noted that, in this conventional process, the machining does not reference the magnetic field axis. Instead, the outer surface of the sintered magnet is referenced. The machining includes grinding the sintered magnet using cutting tools or abrasives. Diamond cutting tools or abrasives can be used for the grinding because the magnet is very hard. Because magnetic material is ground during the machining process, the magnets are made larger during the pressing process so that some of the material can be machined away to achieve the desired dimensions. Alternatively, the magnet can be sliced to achieve the desired dimensions and a flat outer surface. A large block can be further sliced into many blocks of the desired size. The first cut is typically used as a reference for the rest of the machining of the block. Unfortunately, both the machining and slicing processes can result in a large amount of wasted magnetic material that is cut or ground away.
According to an embodiment, the magnetic field axis can be used as a reference for machining the block rather than the outer surface of the block, as in the process described above. In order to use the magnetic field axis as a reference, one must be able to measure the axis, which can be difficult if the block is not magnetized. One of ordinary skill in the art will recognize that there are various known ways to measure the magnetic field axis. For example, one method of measuring the magnetic field axis is to at least partially magnetize the block in order to measure the magnetic field axis, whereas another method of measuring the magnetic field axis is to measure the axis when it is not magnetized.
To know more about Apple's manufacturing process as it relates to the iPad Cover magnets, see Apple's patent application 20120233835 which was filed in Q3 2011 by Cesare Tolentino. Cesare Tolentino interestingly appears to be an independent engineer with many magnet related patents to his credit.
Patent Three: Method and Apparatus for Checking an Acoustic Test Fixture
Apple's patent application 20120234096 which was published today by the US Patent Office relates to a technique for checking or verifying the acoustic capability of a test fixture that is to be used for acoustics testing of a portable media device. Apple was just granted a patent for this invention in June.
Apple Receives Registered Trademarks for VoicePass
Apple filed for the VoicePass trademark on December 17, 2010 and as shown above it has been registered by the US Patent and Trademark Office.
Apple was also granted a registered trademark 4209614 for iChat, though it's a little too late to matter – unless they revive the trademark for something else in the future, thought I highly doubt it.
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