Electronic apparatus estimating ambient temperature and control method thereof
An electronic apparatus comprises a first thermometer and a second thermometer arranged such that a change over time of a difference between a first measurement obtained by the first thermometer and a second measurement obtained by the second thermometer satisfies a specific condition. The electronic apparatus executes control for restricting a function of the electronic apparatus in response to a temperature of a housing of the electronic apparatus exceeding a threshold. The electronic apparatus estimates an ambient temperature based on the first measurement, the second measurement, and the specific condition and sets the threshold based on the estimated ambient temperature.
1 . An electronic apparatus comprising:
a first thermometer;
a second thermometer,
wherein the first thermometer and the second thermometer are arranged such that a change over time of a difference between a first measurement obtained by the first thermometer and a second measurement obtained by the second thermometer satisfies a specific condition;
a CPU;
a memory that stores a program for, when the program is executed by the CPU, causing the electronic apparatus to function as:
a control unit that executes control for restricting a function of the electronic apparatus in response to a temperature of a housing of the electronic apparatus exceeding a threshold,
wherein the control unit estimates an ambient temperature based on the first measurement, the second measurement, and the specific condition and sets the threshold based on the estimated ambient temperature, and
wherein the control unit sets a second value obtained by adding a predetermined value to the estimated ambient temperature as the threshold.
2 . The electronic apparatus according to claim 1 , further comprising:
a third thermometer provided at or near a surface of the housing of the electronic apparatus,
wherein the control unit executes the control for the restricting in response to a third measurement obtained by the third thermometer exceeding the threshold.
3 . The electronic apparatus according to claim 1 , wherein the first thermometer and the second thermometer are arranged such that the second measurement is greater than the first measurement.
4 . The electronic apparatus according to claim 1 , wherein the change over time is a change over time of a difference between the first measurement and the second measurement from a point in time when power of the electronic apparatus is switched from on to off.
5 . The electronic apparatus according to claim 1 , wherein the specific condition is (i) a difference between the first measurement and the second measurement and (ii) a difference between an ambient temperature and the first measurement being proportional.
6 . The electronic apparatus according to claim 5 , wherein the control unit obtains the estimated ambient temperature by subtracting a first value from one of the first measurement or the second measurement, the first value being obtained by multiplying a difference between the first measurement and the second measurement by a predetermined coefficient.
7 . The electronic apparatus according to claim 1 , wherein in a case where a difference between the first measurement and the second measurement is less than a predetermined first constant, the control unit sets the threshold using the first measurement as the estimated ambient temperature.
8 . The electronic apparatus according to claim 1 , wherein in a case where a difference between the first measurement and the second measurement is greater than a predetermined second constant, the control unit sets the threshold using a most recently estimated ambient temperature as the estimated ambient temperature.
9 . The electronic apparatus according to claim 1 , further comprising:
a component that is a heat source;
a fourth thermometer provided at or near the component,
wherein the control unit executes second control for restricting a function of the electronic apparatus in response to a fourth measurement obtained by the fourth thermometer exceeding a second threshold.
10 . The electronic apparatus according to claim 1 , wherein the control unit stores information of the estimated ambient temperature in the memory in response to a power off instruction.
11 . The electronic apparatus according to claim 1 , further comprising:
a fifth thermometer for the CPU;
wherein the control unit executes control for restricting a function of the electronic apparatus in response to a fifth measurement obtained by the fifth thermometer exceeding a third threshold.
12 . The electronic apparatus according to claim 1 , wherein the electronic apparatus is a portable apparatus.
13 . A method of controlling an electronic apparatus, wherein the electronic apparatus comprises:
a first thermometer; and
a second thermometer;
wherein the first thermometer and the second thermometer are arranged such that a change over time of a difference between a first measurement obtained by the first thermometer and a second measurement obtained by the second thermometer satisfies a specific condition;
the method comprising:
executing control for restricting a function of the electronic apparatus in response to a temperature of a housing of the electronic apparatus exceeding a threshold,
wherein the executing control includes
estimating an ambient temperature based on the first measurement, the second measurement, and the specific condition,
setting the threshold based on the estimated ambient temperature,
wherein the setting sets a second value obtained by adding a predetermined value to the estimated ambient temperature as the threshold.
14 . The electronic apparatus according to claim 9 , wherein the component Of the heat source is an image sensor.