Projector and lamp unit

A light source for use in an image projection apparatus, comprising:

• a light-emitting portion;
• a held portion that is held by the image projection apparatus when the light source is fitted in a predetermined position in the image projection apparatus;
• and
• data holding means for holding position-related data so as to allow a center of the light-emitting portion to be located at a previously specified position when the light source is fitted in the predetermined position.

A projection-type image display apparatus, comprising:

• a lamp output varying device for varying intensity of light output from a lamp;
• a modulation device for performing modulation on the light output from the lamp in accordance with color components of an image;
• and
• a controller for varying how the modulation device performs modulation in accordance with the intensity of the light output from the lamp so as to keep a white balance of a displayed image substantially constant irrespective of the intensity of the light output from the lamp.

A projector comprising:

• a light source;
• a reflector arranged around the light source;
• an image display device for performing spatial modulation on illumination light emitted from the light source on a basis of an image signal so as to form an optical image;
• and
• a projection optical system for projecting the optical image on a projection screen,
• wherein the light source is interchangeable with a light source of a different type, and
• wherein the projector is further provided with:
• an input section for inputting data in accordance with what type of light source is currently fitted;
• and
• a controller for performing a predetermined operation on a basis of the input data.

A projector for projecting an image by using light from a light source, comprising:

• a holding member for holding the light source;
• input means for inputting data in accordance with what type of light source is currently fitted;
• and
• an adjustment mechanism for adjusting a position of the light source by moving the holding member,
• wherein the adjustment mechanism adjusts the position of the light source on a basis of the input data.