1. Technical Field
The disclosure relates to cameras and, more particularly, to a camera with an electroactive telescopic shutter module.
2. Description of the Related Art
Conventional cameras mainly apply an electronic shutter or a mechanical shutter. Both the electronic shutter and the mechanical shutter need a complex drive structure and multiple components to control the response time of the shutter. Therefore, when the camera takes a photograph, the complex components of the shutter generate friction, which makes noises and slows the response speed, thereby affecting the quality of image forming of the camera.
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the camera with an electroactive telescopic shutter module. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The image sensor 20 is received in the second receiving hole 112. A transparent board 21 is positioned on the image sensor 20. The transparent board 21 is utilized for protecting the image sensor 20 from dust and dirt.
The electroactive telescopic unit 34 further includes a first electroactive polymer layer 341, two compliant electrode layers 342, and two second electroactive polymer layers 343. The first electroactive polymer layer 341 is connected with the second electroactive polymer layer 343 via the compliant electrode layer 342. The first electroactive polymer layer 341 has a top surface 3411 and a bottom surface 3412. One of the two compliant electrode layers 342 is positioned on the surface 3411 and the other is positioned on the opposite surface 3412. Each compliant electrode layer 342 has a surface 3421 far from the first electroactive polymer layer 341. The second electroactive polymer layer 343 is positioned on the surface 3421 of the compliant electrode layer 342.
A thickness of the first electroactive polymer layer 341 along the optical axis of the lens module 10 is greater than that of the second electroactive polymer layer 343. The thickness of the first electroactive polymer layer 341 is in the range from 0.2 to 0.8 mm. The thickness of the second electroactive polymer layer 343 is in the range from 0.02 to 0.15 mm. A thickness of the compliant electrode layer 342 along the optical axis of the lens module 10 is in the range from 10 to 200 μm.
When the shutter module 30 is in the open state, the center of the electroactive telescopic unit 34 has a through hole 305 along the direction perpendicularly to the optic axis of the lens module 10 through the first electroactive polymer layer 341, the two compliant electrode layers 342, and the second electroactive polymer layers 343. A central axis of the through hole 305 and the optical axis of the lens module 10 are coaxial. The two compliant electrode layers 342 are connected with an electronic circuit (not shown). The electronic circuit provides voltages between the two compliant electrode layers 342 to control the first electroactive polymer layer 341 and the second electroactive polymer layers 343 to contract or expand.
The electroactive telescopic unit 34 is contractible or expandable along the direction perpendicularly to the optical axis of the lens module 10 in response to a change in a voltage applied between the two compliant electrode layers 342, thus changing the diameter of the through hole 305 and controlling the amount of the light passing through the through hole 305. For example, when the voltage between the two compliant electrode layers 342 is in the range from 4 to 7V, the electroactive telescopic unit 34 will contract or expand along the direction perpendicularly to the optical axis of the lens module 10, the diameter of the through hole 305 is changed, and the amount of the light passing through the through hole 305 is adjusted. Therefore, when the voltage between the two compliant electrode layers 342 is equal to 7V, a response time of the electroactive telescopic unit 34 is between several milliseconds and several microseconds, in other words, a response speed of the electroactive telescopic unit 34 is fast.
In this embodiment, the electroactive telescopic unit 34 is a cube. As shown in
The first electroactive polymer layer 341 can be made of silicone, polyurethane elastomer or acrylic elastomer, etc. The second electroactive polymer layer 343 can be also made of silicone, polyurethane elastomer or acrylic elastomer, etc. The compliant electrode layer 342 is positioned on the surface 3411 or the opposite surface 3412 by means of a rotating painting or printing method using carbon colloid, gold colloid, silver colloid or copper colloid, etc, a spray painting method using graphite, a splash plating method using platinum, or an adhesive method using high elasticity carbon nanotubes film. The second electroactive polymer layer 343 is positioned on the surface 3421 by means of a paper coating or adhesive method.
As shown in
It is understood that the disclosure may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the disclosure is not to be limited to the details given herein.
Number | Date | Country | Kind |
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200910304571.3 | Jul 2009 | CN | national |