Motion sensors that detect the movement of people and objects are among Epson's sensing solution technologies. Gyroscopic sensors ("gyro sensors") are one type of motion sensing device. They are capable of sensing movements that are difficult for humans to detect, such as rotation and changes in orientation. The crystal elements in Epson's gyro sensors are made of high-quality quartz crystal grown by Epson and have a double-T structure. They are low noise and offer exceptional sensitivity, temperature characteristics, vibration resistance, and impact resistance.
Gyro sensors, also known as angular velocity sensors, can detect changes in rotation angle per unit of time. This makes it possible to detect quantities such as the direction of rotation, rotation angle, and vibration. Gyro sensors are found in smartphones, digital cameras, game consoles, car navigation systems, robots, industrial equipment, and wherever else features such as vibration detection, camera shake correction, and attitude control are needed.
Gyro sensors are classified according to how they detect rotation. There are vibration gyro sensors, mechanical gyro sensors, and optical gyro sensors, to name a few. Element material and structural differences can cause the accuracy with which angular velocity is measured to differ significantly. The element in a gyro sensor may be made of materials such as quartz, ceramic, or silicon. By modifying and designing the element material and element structure, manufacturers seek to create sensors that are very small and accurate and that feature good device sensitivity, temperature characteristics, impact resistance, stability, and noise characteristics.
Epson manufactures tiny, lightweight vibration gyro sensors that have a thin profile and a crystal unit with a double-T structure. They are produced using a combination of Epson's advanced manufacturing technology for growing high-quality quartz material and Epson's unique microelectro-mechanical system (MEMS) processing technology.
Epson's vibration gyro sensors sense angular velocity from the Coriolis force applied to a vibrating quartz crystal element. Structurally, our gyro sensors consist of a stator, vibrating drive arms on either side of the stator, and a pair of sensing arms that run vertically. Normally, the drive arms vibrate in a certain fixed direction. When the gyro sensor rotates and this rotational motion is applied to the crystal element, the Coriolis force acts on the drive arms, vibration is generated in the vertical direction, the stator bends, and the sensing arms move. The motion of the two sensing arms produces a potential difference from which angular velocity is sensed. The angular velocity is converted to an electrical signal and output.
Epson's gyro sensors are made using our own high-quality synthetic quartz crystal material and have high temperature stability. They also offer exceptional sensitivity and low noise, since even minute forces can be converted into electricity due to the piezoelectric nature of quartz. In addition, our sensors have little vibration that is not needed for sensing and a high signal-to-noise ratio because, with the adoption of the double-T vibrating element, the balance of drive vibration is adjusted for each individual unit. Our gyro sensors are also resistant to vibration and impacts because the arms are highly symmetrical and supported in the center (of gravity), which does not vibrate due to its structure.
Epson will continue to provide various types of gyro sensors that can be used for a wide range of applications, such as camera shake correction, robot vacuum cleaners, and electronic stability control.