Sharp's New Sensor Detects Gestures, Illuminance, Proximity
Sharp Corp developed a proximity sensor equipped with a function to detect the movements (such as gestures) of an object and illuminance sensor function.
It is the industry's first sensor that can detect gestures, illuminance and proximity, Sharp said. The company will start to ship samples of the sensor, "GP2AP050A00F," June 28, 2013, and begin volume production in September 2013 at a monthly rate of three million units. It is targeted mainly at smartphones and tablet computers.
Sharp is now in business negotiations with other companies. And a smartphone equipped with the new proximity sensor is expected to hit the market within 2013.
With the capability to detect gestures, illuminance and proximity, it becomes possible, for example, (1) to move, switch, enlarge and shrink an image displayed on a smartphone screen by moving a hand near the sensor, (2) to change the brightness and color of the display in accordance with the brightness and color of the environment and (3) to prevent malfunctions by stopping the touch panel function when the user is talking on a smartphone and the user's face (cheek) comes close to the touch panel.
Sharp expects that there is a strong demand for such a function for use in high-value-added smartphones. The company predicts that high-value-added smartphones will account for 15-20% of smartphones in the future and that such a trend toward high added values will be strong among new entrants especially China-based phone makers.
The dimensions of the proximity sensor are 5.6 x 2.1 x 1.25mm (H). Its footprint is larger than that of a package that can detect both illuminance and proximity and is contained in smartphones, etc (4.0 x 2.0 x 1.25mm (H)). But, because their heights are the same, the new sensor can be embedded in a smartphone without difficulty, Sharp said.
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According to Sharp, there is another company's product that contains gesture and proximity detection functions in one package. It is possible to realize the same function as that of the new sensor by combining this product and an illuminance sensor, but, in this case, footprint increases, the company said.
"The new sensor can reduce package area by more than 30%," Sharp said.
Color of light source can be determined with illuminance sensor
The illuminance sensor contained in the new proximity sensor detects brightness by separating surrounding light into red (R), green (G) and blue (B) colors. Therefore, it can be used for determining if it is daytime or evening under sunlight and as well as for distinguishing between, for example, daylight color and incandescent color under artificial light such as of lighting apparatus.
"When an image on a display is seen in a bright outdoor environment, the blue and green colors of the image look darkish to human eyes," Sharp said. "On the other hand, under the light of an incandescent lamp, it is difficult to see red and yellow colors."
"With the new sensor, it is possible to realizes a display that emphasizes the blue and green colors of an image in a bright outdoor environment and the red and yellow colors under the light of a light bulb," the company said.
To detect RGB colors, the illuminance sensing part of the new sensor is made by covering photo diodes with RGB filters. Sharp made use of the technologies developed for its image sensors.
For the detection of gestures and proximity, Sharp used infrared LEDs and light-receiving elements. When the infrared light emitted from the LEDs is reflected on an object and enters the light-receiving elements, the sensor detects the movements (gestures) of the object based on the time variations of the illuminated and non-illuminated areas in the light-receiving elements. Proximity can be determined from the intensity of infrared light received by the light-receiving elements.