Proximity Sensor And Ambient Light Sensor (Als); Imaging And Video; Multimedia Application Processor - Nokia RM-701 Service Manual

RM-701
System Module

Proximity Sensor and Ambient Light Sensor (ALS)

This phone uses a combined Proximity and Ambient Light Sensor called DiPro (N1100). DiPro (Digital Proximity
Sensor) is connected to RAPU via a single GENIO (INT=GENIO3) and I2C_0 bus. Supply voltage for DiPro ASIC is
VAUX1 (2.8 V). The Infrared LED used with the Proximity Sensor is supplied by VBAT.
The Proximity Sensor is an optical reflective sensor comprising of an IR LED and a photodetector IC. DiPro sets
the IR LED on and at the same time the photodetector measures the reflected radiation.
One of the typical applications of the Proximity Sensor is for using the INT output as an indication to SW of
a phone being present near to human ear while attending a call. In such a case, the human body will act as
a reflector, due to which more IR rays fall on the photodetector. If irradiance is higher than the limit set by
SW, the INT goes from LOW to HIGH. This LOW to HIGH transition is used as an indication to SW of the presence
of a reflector (human body in this case). SW can then switch off the display and deactivate the touch panel.
Similarly, when the user moves the phone away from the ear, INT goes from HIGH to LOW. This is an indication
to SW that there is no reflector nearby and that the display and touch panel should be switched on and the
touch panel activated.
The Ambient Light Sensor detects the level of ambient light and adjusts the display and key brightness to
enable improved display contrast and energy saving. Covering the Ambient Light Sensor results in dimmed
display and key lights.
Figure 69 Proximity sensor and ALS

Imaging and video

Multimedia application processor

Multimedia application processor, BCM2763C, is used as a HW accelerator for imaging and video graphics.
The key features of BCM2763C are:
• 5 MPIx primary camera
• Single LED flash
• TFT DSI display
• NTSC/PAL analog TV-out
MeSSI-16 and CCP2-Tx are the key interfaces between RapuYama and BCM2763C. BCM2763C has in-build 256Mb
stacked SDRAM.
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