Abstract: Concerning a lamp unit which is used as a light source of an image reading apparatus, there is provided a lamp unit which reduces a change over time in the quantity of light. The lamp unit is provided with a hollow cylindrical gas-filled tube in which a gas is filled; a pair of electrodes which are secured to an outer peripheral surface of the gas-filled tube and extend in the longitudinal direction of the gas-filled tube in a mutually opposing state; an electrically insulating cladding tube surrounding the electrodes and the gas-filled tube; and a heat-accumulating member provided in contact with an outer peripheral surface of the cladding tube and extending in the longitudinal direction of the cladding tube.

Abstract: A data correction subsystem for a color image processing system having a color image reading device and a color image printing device. A chart file is transmitted to the printing device so that the printing device produces a sample chart. Calibration data is calculated from read sample data so that the read sample data can be corrected to corresponding data in the chart file. The read sample data is obtained by causing the reading device to read the sample chart. Printing data to be transmitted to the printing device is corrected using the calibration data.