JVC 250 service manual Optical Section, Igniter Assembly, Arc Lamp Module, Optical Path

Chapter 2---System Description

Igniter Assembly

The Igniter Assembly provides the high voltage pulse that lights the Arc Lamp and acts as a link from the Arc Lamp Power Supply to the Arc Lamp after the Arc Lamp has been lit.

!Igniter - The Igniter actually performs three functions. It is a step-up transformer that supplies the high voltage pulse to light the Arc Lamp. It also supplies the spark gap for the high voltage pulse. Once the Arc Lamp is lit, the Igniter acts as a link between the Arc Lamp Power Supply and the Arc Lamp for steady state operation.

!Laser Power Supply - The Laser Power Supply provides the voltage for the spark gap. The spark gap produces a high voltage pulse in the Igniter that lights the Arc Lamp.

2.3Optical Section

The optical section of the Model 250 consists of the Arc Lamp Module, the Optical Path, the ILA® , the CRTs, the Relay Lenses and the Projection Lens.

Arc Lamp Module

The Arc Lamp Module supplies high intensity light for the Model 250. Its output is rated at 2 kW. The Arc Lamp has an expected 50% lifetime (half of initial light output) of 1000 hours.

Optical Path

The Optical Path consists of all the optical components that transmit, filter, separate, bend, or straighten the Arc Lamp light. The Optical Path also includes Polarizing Prisms, Prepolarizing Prisms, Steering Prisms and the 4P Combining Prism that control the image path inside the Prism Assembly.

!Cold Mirrors (3) - The Cold Mirrors remove infrared light rays, which contain most of the heat, from the white light coming from the Arc Lamp. There are three Cold Mirrors, the first one is located in front of the Arc Lamp, and the other two are located after the Light Pipe.

CAUTION! The term "cold mirror" is used because the mirror passes infrared light and its reflection contains only "cold' light that does not transmit appreciable heat. As a result of the absorption of infrared heat radiation, "cold" mirrors get very hot.

!Light Pipe - The Light Pipe acts as an Integrator to spread out the beam of light creating a uniform distribution of light across the face of the ILA® . This will result in a more uniform image on the screen

Model 250 Service Manual 2-3