Plastic Window; Dust Seal; Lcd Adhesive; Reflector - Nokia NSB-5 Series Technical Documentation Manual

NSB-5
System Module

Figure 21: Mounting of LEDs for backlight (seen from underside)

Plastic Window

The window is mounted on top of the LCD module. It snaps into the light guide in three
places. If a broken window needs to be replaced, it is replaced together with the dust
seal.

Dust Seal

The dust seal is made of foam with adhesive backing on both sides. It keeps dust out of
the LCD module and protects it from excessive pressure on the window, if pressed too
hard. The dust seal is mounted inside the window and placed onto the LCD module. The
window adhesive is high tack. The LCD adhesive is low tack to ease replacement of the
window.

LCD Adhesive

This is a thin strip of foil with adhesive on both sides. It keeps the LCD module in place
and protects it if the phone is dropped.

Reflector

The reflector is adhered to the underside of the light guide to reflect the backlight up to
the viewing area. A thin adhesive border holds it in place and also keeps out dust.

Connector

The connector makes a mechanical connection between light guide and LCD, so the LCD
can be clicked onto the light guide. Also, it makes electrical connection between LCD cell
and PCB. The connector is not attached to the PCB, but the 14-pin connector contains
springs and makes the contact.

Light Guide

The light guide houses and connects the LCD module to the PCB and backlights the dis-
play. Several snap fits locate the window and a board-to-board connector.
Evenly distributed backlighting is controlled by a graduated etched pattern. The pattern
becomes rougher the further it gets from the LEDs. This is on the underside, in the visual
area. The rest of the light guide is polished to minimize light losses in the system.
Page 88
Nokia Mobile Phones Ltd.
PAMS Technical Documentation
Issue 1 03/01