Patent ID: 11867573
Assignee: JAPAN DISPLAY INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 12:
13. A head up display comprising:
a display panel configured to display an image; and
a temperature detection device arranged so as to overlap with a display surface of the display panel, wherein
the temperature detection device includes:
a detection part in which a first resistor element and a second resistor element having different relations between temperature variation and variation in an electric resistance value are provided;
a switch provided capable of performing a switching operation so as to be coupled to one of a first circuit including wiring to which the first resistor element is coupled and a second circuit including wiring to which the second resistor element is coupled;
a power supply circuit configured to apply a voltage to the one circuit coupled to the power supply circuit through the switch to generate an electric signal in the one circuit; and
a controller configured to detect a temperature of the detection part based on a strength of the electric signal output from the one circuit, and

the controller is configured to periodically cause the switch to perform the switching operation,
variation in the electric signal occurs in the first circuit based on temperature variation of equal to or lower than 1° C. when a detection temperature range of the detection part is a first temperature range,
variation in the electric signal occurs in the second circuit based on temperature variation of equal to or lower than 1° C. when the detection temperature range of the detection part is a second temperature range,
the first temperature range does not overlap with the second temperature range, and
the controller detects a temperature in a third temperature range not overlapping with the first temperature range and the second temperature range, based on both of the electric signal generated in the first circuit and the electric signal generated in the second circuit.