Cooling device and display device

Patent metadata

Field	Value
Publication number	US-11320178-B2
Application number	US-202016831662-A
Country	US
Kind code	B2
Filing date	Mar 26, 2020
Priority date	Mar 29, 2019
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

The cooling device includes an electrocaloric portion including an electrocaloric effect material, a first thermal switch including a first actuator, and a second thermal switch including a second actuator, in which a thickness and a length of the first actuator and the second actuator are changed depending on an electric field to be applied.

First claim

What is claimed is:

1. A cooling device comprising:
a heat source;
a heat sink; and
an actuator provided between the heat source and the heat sink,
wherein the actuator includes a first actuator and a second actuator of each of which a thickness and a length vary depending on an applied electric field,
wherein the cooling device further comprises, between the heat source and the heat sink,
an electrocaloric portion that includes an electrocaloric effect material having exothermic characteristics in an ON state where an electric field is applied, and endothermic characteristics in an OFF state where an electric field is not applied, and a plurality of first electrodes for applying an electric field to the electrocaloric effect material;
a first thermal switch that includes a first low thermal conductive medium, the first actuator having a higher thermal conductivity than that of the first low thermal conductive medium, and a plurality of second electrodes for applying an electric field to the first actuator, and in which a heat transfer amount from the heat source to the electrocaloric effect material in a first state is larger than a heat transfer amount from the heat source to the electrocaloric effect material in a second state; and
a second thermal switch that includes a second low thermal conductive medium, the second actuator having a higher thermal conductivity than that of the second low thermal conductive medium, and a plurality of third electrodes for applying an electric field to the second actuator, and in which a heat transfer amount from the electrocaloric effect material to the heat sink in a third state is larger than a heat transfer amount from the electrocaloric effect material to the heat sink in a fourth state,
wherein in a first period, the electrocaloric portion is in an OFF state, the first thermal switch is in the first state, and the second thermal switch is in the fourth state, and
wherein in a second period, the electrocaloric portion is in an ON state, the first thermal switch is the second state, and the second thermal switch is in the third state.

2. The cooling device according to claim 1 ,
wherein the first thermal switch, the electrocaloric portion, and the second thermal switch are provided between the heat source and the heat sink in this order from the heat source side.

3. The cooling device according to claim 2 ,
wherein the plurality of second electrodes are provided on a surface of the heat source facing the electrocaloric portion.

4. The cooling device according to claim 2 ,
wherein a first high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat source facing the electrocaloric portion, and
wherein the plurality of second electrodes are provided on a surface of the first high thermal conductive layer facing the electrocaloric portion.

5. The cooling device according to claim 4 ,
wherein a second high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat sink facing the electrocaloric portion, and
wherein the plurality of third electrodes are provided on a surface of the second high thermal conductive layer facing the electrocaloric portion.

6. The cooling device according to claim 5 ,
wherein a third high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat source facing the heat sink, and
wherein the plurality of second electrodes are provided on a surface of the third high thermal conductive layer facing the heat sink.

7. The cooling device according to claim 6 ,
wherein a fourth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat sink facing the heat source, and
wherein the plurality of third electrodes are provided on a surface of the fourth high thermal conductive layer facing the heat source.

8. The cooling device according to claim 7 ,
wherein the plurality of second electrodes are configured to include a second upper electrode and a second lower electrode,
wherein a fifth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat source facing the heat sink,
wherein a sixth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat sink facing the heat source,
wherein the second upper electrode is provided on a surface of the fifth high thermal conductive layer facing the heat sink, and
wherein the second lower electrode is provided on a surface of the sixth high thermal conductive layer facing the heat source.

9. The cooling device according to claim 8 ,
wherein the plurality of third electrodes are configured to include a third upper electrode and a third lower electrode,
wherein a third low thermal conductive layer having a thermal conductivity equal to or lower than that of the first actuator and the second actuator is provided on a surface of the heat source facing the heat sink,
wherein a seventh high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided on a surface of the heat sink facing the heat source,
wherein the third upper electrode is provided on a surface of the third low thermal conductive layer facing the heat sink, and
wherein the third lower electrode is provided on a surface of the seventh high thermal conductive layer facing the heat source.

10. The cooling device according to claim 9 ,
wherein an eighth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided between the first thermal switch and the heat sink.

11. The cooling device according to claim 9 ,
wherein a fourth low thermal conductive layer having a thermal conductivity equal to or lower than that of the first actuator and the second actuator is provided between the second thermal switch and the heat source.

12. The cooling device according to claim 10 ,
wherein a ninth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided between the first actuator in the first thermal switch and the electrocaloric effect material in the electrocaloric portion.

13. The cooling device according to claim 12 ,
wherein a tenth high thermal conductive layer having a higher thermal conductivity than that of the first low thermal conductive medium and the second low thermal conductive medium is provided between the second actuator in the second thermal switch and the electrocaloric effect material in the electrocaloric portion.

14. The cooling device according to claim 2 ,
wherein the plurality of third electrodes are provided on a surface of the heat sink facing the electrocaloric portion.

15. The cooling device according to claim 2 ,
wherein the plu

Assignees

• Sharp Kk

Inventors

• Haseba Yasuhiro
• Minoura Kiyoshi

Classifications

• F25B2321/001

  by using electro-caloric effects · CPC title

• H01H37/32

  Thermally-sensitive members · CPC title

• H01H71/14

  Electrothermal mechanisms {(combined with a electro-thermal time delay relay H01H61/002)} · CPC title

• H05K7/20954 Primary

  for display panels · CPC title

• F25B21/00 Primary

  Machines, plants or systems, using electric or magnetic effects · CPC title