PAW3603DH-NF Datasheet, PDF (3/32 Pages) Pixart Imaging Inc. – LOW POWER WIRELESS LASER MOUSE SENSOR

PixArt Imaging Inc.
PAW3603DH-NF
2. Block Diagram and Operation
CMOS Laser Mouse Sensor
Figure 3. Block Diagram
In the traditional optical mouse, it uses LED as a light source. The light illuminates on the working surface and
generates the bright and dark shadow that shows the micro-texture of the surface. The imaging sensor in the
optical mouse chip captures sequential this micro-texture images of the working surface. Based on the captured
images, the optical chip can determine the speed and direction when the optical mouse is moving. Thus, for the
more rough surface, the more obvious shadow image will be generated and much easier to determine the
movement and direction.
The PAW3603DH-NF is a CMOS laser mouse sensor with DSP integration chip that serves as a non-
mechanical motion estimation engine for implementing a computer mouse. It is based on new laser speckle
navigation technology. In the laser mouse, it uses laser diode (LD), specially uses VCSEL (Vertical Cavity
Surface Emitting Laser) as light source, where laser is one kind of coherent light. When this light illuminates on
the working surface, the surface will reflect and diffuse the incident light and generates speckle pattern. The
imaging sensor in the laser mouse chip detects the speckle pattern that generated from the working surface and
determines the movement and direction. Since the speckle pattern can be generated on the most of the surface if
this surface is not perfect smooth or transparent, the laser mouse can adapt on more surfaces as compared with
traditional LED-based optical mouse. The sensor is in a 20-pin optical package. The output format is two-
channel quadrature (X and Y direction), which emulates encoder phototransistors. The current X and Y
information are also available in registers accessed via a serial port. The word "mouse sensor," instead of
PAW3603DH-NF, is used in the document.
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PixArt Imaging Inc.
E-mail: [e-mail]
V1.0, Aug. 2007