The engineers disassembled a new Play Station Portable "PSP-2000" and an old model "PSP-1000" (See related article 1, See related article 2). And they turned their eyes from the printed-circuit boards to the LCD panels of the PSP-2000 and PSP-1000.
We realized that, in the PSP-2000, there is no metal part in the front of the LCD. This part was probably omitted to reduce the weight. The LCD panel of the PSP-2000 is 2.5 mm thick and weighs 26 g. The LCD panel of the PSP-1000 is 4.0 mm thick and weights 49 g. So, the LCD panel of the PSP-2000 is 1.5 mm thinner and 23 g lighter than that of the PSP-1000.
The thickness of 2.5 mm "is not significantly thinner than the LCD panels used in recent mobile-phones," one of the engineers said.
The LCD panels mounted in the PSP-1000 (left) and PSP-2000 (right). The cover in the front of the LCD panel is omitted in the PSP-2000. Also, the PSP-2000's flexible substrate is smaller.
The LCD panel of the PSP-2000 (right) is 2.5 mm thick, 1.5 mm thinner than that of the PSP-1000 (left).
We found a difference between the two models when we removed a metal cover in the front of the PSP-1000's LCD. In the PSP-1000, four driver ICs are embedded on the glass terminal port of the LCD panel. On the other hand, in the PSP-2000, no driver IC is mounted on the glass. It seems that LCD driver circuits, such as a gate driver and source driver, are formed on the glass substrate.
The LCD panels of the PSP-1000 (left) and PSP-2000 (right) with their front covers removed. Driver ICs are formed on the glass of the PSP-2000's LCD panel. The flexible substrate in the PSP-2000 is small. On the glass substrate of the PSP-1000's LCD panel, driver ICs are embedded.
Furthermore, we dismantled the backlight parts of the LCDs. The thicknesses of the glasses for the PSP-1000 and PSP-2000 are 1.4 mm and 0.6 mm, respectively. Seemingly, the LCD panel was thinned mainly by reducing the thickness of the glass.
The glass of the PSP-1000's LCD panel (left) is 1.4 mm thick, and that of the PSP-2000's LCD panel (right) is 0.6 mm thick.