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Image credit: National Instruments Corporation With X4 encoding, both the rising and falling edges of channels A and B are counted. This provides a four-fold increase in resolution, since now, four edges are counted. X4 encoding counts both the rising and falling edges of both channels A and B. So a 1000 PPR encoder that uses X2 encoding has a resolution of 2000 PPR. And with twice the edges counted, the encoder’s resolution is doubled. X2 encoding counts both the rising and falling edges of channel A are counted. X1 encoding counts either the rising or falling edge of channel A.
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And, with quadrature output, any one of three types of encoding can be employed: X1, X2, or X4. With two sets of pulses, the encoder can determine both position and direction, based on which channel is leading and which is trailing. This is why most incremental encoders use quadrature encoding, which produces two sets, or channels, of pulses – A and B – that are out of phase from each other by 90 degrees (hence the term “quadrature”).
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When an incremental encoder outputs just one set of pulses, only position can be determined – not direction. The resolution of a linear encoder can also be specified in terms of microns, which refers to the distance between pulses. These square-wave pulses are very precisely spaced, and the encoder determines its position by counting the number of pulses generated during a movement. For incremental encoders, resolution is typically specified in pulses per revolution (PPR), or, in the case of linear encoders, pulses per inch (PPI) or pulses per millimeter (PPM). It is also recommended to avoid regular use for prolonged periods to further lessen the risk of damage.Resolution is one of the most important indicators of an encoder’s performance. Attaching your iPhone to vehicles with small-volume or electric engines, such as mopeds and scooters, may lead to comparatively lower-amplitude vibrations, but if you do so a vibration dampening mount is recommended to lessen the risk of damage to your iPhone and its OIS and AF systems. It is not recommended to attach your iPhone to motorcycles with high-power or high-volume engines due to the amplitude of the vibration in certain frequency ranges that they generate. High-power or high-volume motorcycle engines generate intense high-amplitude vibrations, which are transmitted through the chassis and handlebars. It is recommended to avoid exposing your iPhone to extended high-amplitude vibrations. However, as is the case with many consumer electronics that include systems like OIS, long-term direct exposure to high-amplitude vibrations within certain frequency ranges may degrade the performance of these systems and lead to reduced image quality for photos and videos. The OIS and closed-loop AF systems in iPhone are designed for durability.
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With closed-loop AF, on-board magnetic sensors measure gravity and vibration effects and determine the lens position so that the compensating motion can be set accurately. 2 Closed-loop AF resists the effects of gravity and vibration to preserve sharp focus in stills, videos, and panoramas. To reduce image motion, and the resulting blur, the lens moves according to the angle of the gyroscope.Īdditionally, some iPhone models have closed-loop autofocus (AF). With OIS, a gyroscope senses that the camera moved. 1 OIS lets you take sharp photos even if you accidentally move the camera. To prevent this, some iPhone models have optical image stabilization (OIS). If you accidentally move a camera when you take a picture, the resulting image can be blurry. These systems work to automatically counteract movement, vibrations, and the effects of gravity to let you focus on taking a great shot. The advanced camera systems in some iPhone models include technology like optical image stabilization and closed-loop autofocus to help you capture great photos even in difficult conditions. The iPhone camera helps you take great photos in any situation-from everyday moments to studio-quality portraits.