Abstract: An illumination controller determines a target brightness setting value from a illuminance value measured by a illumination sensor, determines a brightness correction start time in response to a target brightness setting value and a current brightness setting value and a calculation information that are stored in a memory, calculates an amount of brightness setting change per specified time from the current brightness setting value stored in the memory and the target brightness setting value at a brightness correction start time, and outputs an output brightness setting value in response to the amount of brightness setting change that is calculated. The brightness controller adjusts brightness of the display unit in response to the output brightness setting value output from the illumination controller.

Abstract: An illumination controller determines a target brightness setting value from a illuminance value measured by a illumination sensor, determines a brightness correction start time in response to a target brightness setting value and a current brightness setting value and a calculation information that are stored in a memory, calculates an amount of brightness setting change per specified time from the current brightness setting value stored in the memory and the target brightness setting value at a brightness correction start time, and outputs an output brightness setting value in response to the amount of brightness setting change that is calculated. The brightness controller adjusts brightness of the display unit in response to the output brightness setting value output from the illumination controller.

Abstract: The invention provides a device for effectively decreasing the electric field irradiated from the front surface of a CRT display. This device cancels the leakage field composed of a deflection component and a high voltage ripple component irradiated in the front direction of the CRT by generating an inverse electric field composed of the deflection component and high voltage ripple component. The inverse electric field is obtained by detecting an alternating-current voltage irradiated in the anode portion of the CRT by capacitive coupling a detector to the anode, inverting and amplifying the detected voltage, and applying the inverted voltage to an inverse field generating means installed near the front surface of the CRT.