HALF MIRROR, METHOD FOR MANUFACTURING THE SAME AND LIGHTING UNIT USING THE SAME

• US 20170176655A1
• Filed: 12/14/2016
• Published: 06/22/2017
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: KUROKI, Kazushige, SUZUKI, Yoshio
• Granted Patent: US 10,429,554 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/205 by cathodic sputtering
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: C23C 14/5853 Oxidation
• CPC Class Codes: F21S 41/275 Lens surfaces, e.g. coatings or surface structures
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: G02B 27/14 operating by reflection only
• CPC Class Codes: G02B 27/142 Coating structures, e.g. thin films multilayers
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 5/0808 having a single reflecting layer G02B5/0883, G02B5/0891 take precedence

Abstract

A half mirror, a method for manufacturing the half mirror and a lighting unit using the half mirror can include a base material and a half mirror layer formed on the base material. The half mirror layer can include a chrome oxide layer, which is made by only a sputtering method, and can be configured to perform a high thermal resistance. Accordingly, the half mirror cannot crack even under various circumstances such that repeat low/high temperatures. Thus, the disclosed subject matter can provide half mirrors having a high durability such as a thermal resistance and methods for manufacturing such the half mirrors in simple manufacturing processes, and also can provide lighting units using the half mirror having a high durability, which can maintain a stable reflectivity for a long term and which can also maintain a good appearance for a long-term use because the half mirror can prevent cracking therein.

Claims

1. A half mirror, comprising:

a base material having a first surface and a second surface formed in a substantially planar shape and made from a transparent material; and

a half mirror layer having a central line including chrome oxide and formed on at least one of the first surface and the second surface of the base material as a chrome oxide layer, wherein a distributional minimum of a ratio of oxide atomic element to chrome atomic element in a thick direction of the half mirror layer toward the base material is 0.55 or more.

2. The half mirror according to claim 1, wherein a distributional maximum of the ratio of the oxide atomic element to the chrome atomic element in the thick direction of the half mirror layer toward the base material is 0.86 or less.

3. The half mirror according to claim 1, wherein a distributional minimum of oxide composition of the chrome oxide layer in the thick direction of the half mirror layer toward the base material is 35 atomic percent (at %) or more.

4. The half mirror according to claim 1, wherein a distributional maximum of oxide composition of the chrome oxide layer in the thick direction of the half mirror layer toward the base material is 46 at % or less.

5. The half mirror according to claim 1, wherein a ratio of oxide atomic element to chrome atomic element on the central line in the thick direction of the half mirror layer 2 toward the base material is 0.67 or more.

6. The half mirror according to claim 2, wherein the base material includes a polycarbonate resin.

7. A method for manufacturing the half mirror according to claim 1, comprising:

preparing the base material;

forming a chrome layer on the base material by a sputtering method, wherein a pressure of argon gas in a coating chamber of a sputtering equipment is more than 1.5 Pa, and a power is less than 1,500 watts when a direct current (DC) is applied between a positive electrode connecting the base material and a negative electrode connecting a chromium target; and

forming the chrome oxide layer on the base material 3 by injecting oxygen or a gas including the oxygen in the coating chamber of the sputtering equipment.

8. A method for manufacturing the half mirror according to claim 2, comprising:

preparing the base material;

forming a chrome layer on the base material by a sputtering method, wherein a pressure of argon gas in a coating chamber of a sputtering equipment is more than 1.5 Pa, and a power is less than 1,500 watts when DC is applied between a positive electrode connecting the base material and a negative electrode connecting a chromium target; and

forming the chrome oxide layer on the base material by injecting oxygen or a gas including the oxygen in the coating chamber of the sputtering equipment.

9. A method for manufacturing the half mirror according to claim 3, comprising:

preparing the base material;

forming a chrome layer on the base material by a sputtering method, wherein a pressure of argon gas in a coating chamber of a sputtering equipment is more than 1.5 Pa, and a power is less than 1,500 watts when DC is applied between a positive electrode connecting the base material and a negative electrode connecting a chromium target; and

forming the chrome oxide layer on the base material by injecting oxygen or a gas including the oxygen in the coating chamber of the sputtering equipment.

10. A method for manufacturing the half mirror according to claim 4, comprising:

preparing the base material;

forming a chrome layer on the base material by a sputtering method, wherein a pressure of argon gas in a coating chamber of a sputtering equipment is more than 1.5 Pa, and a power is less than 1,500 watts when DC is applied between a positive electrode connecting the base material and a negative electrode connecting a chromium target; and

forming the chrome oxide layer on the base material by injecting oxygen or a gas including the oxygen in the coating chamber of the sputtering equipment.

11. A lighting unit using the half mirror according to claim 1, comprising:

a casing having an opening and an inner surface, and the opening of the casing attached to the half mirror; and

a light source attached to the casing and facing the half mirror.

12. A lighting unit using the half mirror according to claim 2, comprising:

a casing having an opening and an inner surface, and the opening of the casing attached to the half mirror; and

a light source attached to the casing and facing the half mirror.

13. A lighting unit using the half mirror according to claim 3, comprising:

a casing having an opening and an inner surface, and the opening of the casing attached to the half mirror; and

a light source attached to the casing and facing the half mirror.

14. A lighting unit using the half mirror according to claim 4, comprising:

a casing having an opening and an inner surface, and the opening of the casing attached to the half mirror; and

a light source attached to the casing and facing the half mirror.

15. The lighting unit according to claim 11, wherein the inner surface of the casing is a reflective surface.

16. The lighting unit according to claim 12, wherein the inner surface of the casing is a reflective surface.

17. The lighting unit according to claim 13, wherein the inner surface of the casing is a reflective surface.

18. The lighting unit according to claim 14, wherein the inner surface of the casing is a reflective surface.

19. The lighting unit according to claim 11, wherein the light source includes a laser device.

20. The lighting unit according to claim 12, wherein the light source includes a laser device.