Abstract: A projection lens includes a first lens group, a second lens group and an aperture stop. The first lens group is disposed between a reduced side and a magnified side. The second lens is disposed between the first lens group and the magnified side. The second lens group has a light incident surface, a reflective surface and a light emitting surface, the light incident surface faces the first lens group, the light emitting surface faces a projection surface, the light incident surface, the light emitting surface and the first lens group are disposed at a single side of the reflective surface, and at least one of the light incident surface, the reflective surface and the light emitting surface is a freeform surface. The aperture stop is disposed between the first lens group and the second lens group. Moreover, a projection apparatus including the projection lens is also provided.

Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: A discharge electrode structure which is a substantially II-shaped sheet unit integrally made from one single blank sheet. The discharge electrode sheet unit includes two conductive sections connected with each other by two bridge sections at two ends. Two sides of each bridge section are formed with screw holes. Each conductive section is formed with a middle transverse bar formed with multiple perpendicular discharge needles at equal intervals. Each discharge needle has a tip. After the discharge electrode is connected with a DC high voltage power supply, free electrons are produced by discharging. The tips of the discharge needles are perpendicularly arranged at equal intervals so that ionic equilibrium can be easily achieved.

Abstract: An electrode panel-drawing device of a static ion discharger, including a box body. A top section of the box body is formed with an opening. A bottom section of the box body is disposed with a connecting seat. The box body is disposed with ventilators, an activating switch and an adjustment button. A motor, a fan and an AC-to-DC circuit board are disposed in the box body. A drawer body is fitted into the opening of the box body. The drawer body is disposed with discharge needles and electrode panels at equal intervals. The positive terminal of the circuit board is connected to the discharge needles, while the negative terminal of the circuit board is connected to the electrode panels. The positive discharge needles ionize the air to eliminate the static electricity. The drawer body can be drawn out of the box body for directly washing the discharge needles and the electrode panels.