Liquid crystal shutter device for a camera

• US 7,450,187 B2
• Filed: 05/24/2006
• Issued: 11/11/2008
• Est. Priority Date: 11/23/2005
• Status: Expired due to Fees

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Sun, Wen-Hsin
• Primary Examiner(s): Font; Frank G
• Assistant Examiner(s): Blevins; Jerry
• Application Number:
  US11/440,389
• Publication Number:
  US 20070115211A1
• Time in Patent Office: 902 Days
• Field of Search: 349/149, 349/2, 345 50- 54, 396/249
• US Class Current: 349/2
• CPC Class Codes: G02F 1/13378 by treatment of the surface, e.g. embossing, rubbing or light irradiation G02F1/133711, G02F1/133734, G02F1/133753 take precedence
• CPC Class Codes: G02F 1/133796 having conducting property
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G02F 2203/48 Variable attenuator
• CPC Class Codes: G03B 9/08 Shutters

Abstract

A liquid crystal shutter (100) and a camera (200) with therein. The liquid crystal shutter (100) includes a power supply (10), a switch (20) and a liquid crystal box (40), all parts are electrically connected and form a control circuit. The liquid crystal box (40) includes a first electric plate (42), a first polarizing filter (424), a second electric plate (44), and a second polarizing filter (444). A predetermined amount of liquid crystal (46) is contained between the first electric plate (42) and the second electric plate (44). The first polarizing filter (424) is formed on a surface of the first electric plate (42). A second polarizing filter (444) is formed on a surface of the second electric plate (44). The axial direction of the second polarizing filter (444) is perpendicular to that of the first polarizing filter (424).

Claims

1. A liquid crystal shutter device for a camera, comprising:

a power supply;

an image recording plate;

a switch having first and second positions, wherein when the switch is in one of its positions, light is allowed to enter the camera through the shutter device to be recorded on the image recording plate, and when the switch is in its other position, light is prevented from entering the camera through the shutter device and being recorded on the image recording plate;

a liquid crystal box connected to the power supply and the switch, the liquid crystal box including;

a first electric plate, including a first transparent base and a first transparent electroplated layer, the first base being coated with the first electroplated layer;

a first polarizing filter formed on a surface of the first electric plate;

a second electric plate parallel to the first electric plate, the second electric plate including a second transparent base and a second transparent electroplated layer, the second base being coated with the second electroplated layer;

a second polarizing filter, the axial direction of the second polarizing filter being perpendicular to that of the first polarizing filter, the second polarizing filter being formed on a surface of the second electric plate; and

a predetermined amount of liquid crystal contained between the first electric plate and the second electric plate;

wherein the power supply, the switch, and the liquid crystal box are electrically connected in series and form a control circuit.

2. The liquid crystal shutter device as claimed in claim 1, wherein the first and second bases are made of glass.

3. The liquid crystal shutter device as claimed in claim 1, wherein the first and second electroplated layers are made of an oxide of indium and tin.

4. The liquid crystal shutter device as claimed in claim 1, wherein the liquid crystal shutter device further comprises a rheostat capable of adjusting the voltage difference between the first electric plate and the second electric plate.

5. The liquid crystal shutter device as claimed in claim 1, wherein the liquid crystal is made of nematic phase material.

6. The liquid crystal shutter device as claimed in claim 5, wherein the liquid crystal is selected from the group consisting of lithium niobate, lithium molybdate, and potassium dihydrogen phosphate.

7. A camera comprising:

a lens module; and

a liquid crystal shutter located in front of the lens module, the liquid crystal shutter including;

a power supply;

a switch;

a liquid crystal box connected to the power supply and the switch, the liquid crystal box including;

a first electric plate having a plurality of first parallel grooves defined therein;

a first polarizing filter formed on a surface of the first electric plate, an extending direction of the first parallel grooves of the first electric plate being the same as an axial direction of the first polarizing filter;

a second electric plate parallel to the first electric plate, the second electric plate having a plurality of second parallel grooves defined therein, an extending direction of the second parallel grooves being perpendicular to that of the first parallel grooves;

a second polarizing filter, the axial direction of the second polarizing filter being perpendicular to that of the first polarizing filter, the second polarizing filter being formed on a surface of the second electric plate; and

a predetermined amount of liquid crystal contained between the first electric plate and the second electric plate;

wherein the power supply, the switch, and the liquid crystal box are electrically connected in series and form a control circuit, and wherein the control circuit further includes a rheostat capable of adjusting the voltage between the first electric plate and the second electric plate.

8. The camera as claimed in claim 7, wherein at least one of the first and second electric plates comprises a base and an electroplated layer, the base being coated with the electroplated layer.

9. The camera as claimed in claim 8, wherein the electroplated layer is made of an oxide of indium and tin.

10. A liquid crystal shutter device for a camera, comprising;

a first transparent electric plate with a plurality of first parallel grooves formed in one surface thereof;

a first transparent polarizing filter formed an opposite surface of the first electric plate, the first polarizing filter having a first optical axis parallel to the first grooves;

a second transparent electric plate spaced from and parallel to the first electric plate, the second electric plate having a plurality of second parallel grooves formed in one surface thereof, the second grooves being substantially perpendicular to the first grooves, the surfaces of the first and second electric plates that form the first and second grooves facing each other;

a second transparent polarizing filter formed on an opposite surface of the second electric plate, the second polarizing filter having a second optical axis parallel to the second grooves;

a predetermined amount of liquid crystal molecules contained between the first electric plate and the second electric plate; and

a switch circuit connected to the first and second electric plates so as to selectively establish an electric field between the first and second electric plates for changing a direction of the liquid crystal molecules, thereby selectively allowing the rays of light to pass through and stopping the rays of light from passing trough the first and second polarizing filters.

11. The liquid crystal shutter device as claimed in claim 10, wherein the liquid crystal shutter device further comprises a rheostat capable of adjusting the voltage difference between the first electric plate and the second electric plate.

12. The liquid crystal shutter device as claimed in claim 10, wherein the liquid crystal is made of nematic phase material.