Patent Application
20060142053
This invention relates generally to lens attachments, and more particularly to a method and system for applying a lens or filter to a camera in a communication product.
Most cameras lenses have a fairly narrow field of view. Most lenses are designed to minimize distortion at the expense of a narrow angle. The narrow angle then typically requires the user to be at a larger distance from an object in order to take a picture of a wide scene. When a user cannot step back to take a wide angle scene (such as in a small room), a wide angle lens can be attached to the front of the camera. Attaching a wide angle lens to a camera is often cumbersome since the attachment lens is a separate attachment which can be misplaced or defective. Cell phones are often used to take pictures in confined environments and no known existing communication device having an integrated camera has a convenient means for providing attachments that can alter the focal length, field of view, lighting, or filtering for the integrated camera.
Embodiments in accordance with the present invention can incorporate a wide angle lens, a macro lens, a telephoto lens, a light shade or light filter into the flip of a communication product such as a cell phone. Such incorporation can obviate the use of a separate lens attachment.
In a first embodiment of the present invention, a camera phone in a flip style housing can include a camera incorporated within a first portion of the flip style housing of the camera phone and a lens incorporated within a second portion of the flip style housing of the camera phone. The camera can align substantially with the lens when the first portion pivots relative to the second portion. The lens can be a converter lens that changes the focal length of the camera from among a wide angle lens, a telephoto lens, and a macro lens, according to the converter lens selected. The lens can alternatively be an attachment that serves as a lens hood or a filter such as an ultraviolet filter. Note, the first portion can be a base of the camera phone and the second portion can be a flip portion of the camera phone. Alternatively, the first portion can be a flip portion of the camera phone while the second portion can be a base of the camera phone. The camera phone can also include at least one display such as a main display on the flip portion or an auxiliary display on an opposing side of the flip portion which enables viewing without the lens when the camera phone is in an open position. Another display or the auxiliary display on the opposing side of the flip portion can enable viewing with the lens when the camera phone is in a closed position. To provide for sufficient tolerance between the camera and the lens, a lens exit pupil can be constructed to be significantly larger than a camera entrance pupil.
In a second embodiment of the present invention, a communication device in a clam shaped housing can include a camera incorporated within a first portion of the clam-shaped housing of the communication device and a lens incorporated within a second portion of the clam-shaped housing of the communication device. The camera and the lens can substantially align when the first portion pivots relative to the second portion. The lens can be an afocal converter lens that changes an effective focal length of a lens of the camera from among a wide angle lens, a telephoto lens, and a macro lens in accordance to the afocal converter lens selected. Note, the first portion can be a base of the communication device and the second portion can be a flip portion of the communication device. Alternatively, the first portion can be a flip portion of the camera phone while the second portion can be a base of the camera phone. The communication device can include at least one display and can also include a keypad on the first portion. In one embodiment, the communication device can have at least one among a main display on a flip portion of the communication device or an auxiliary display on an opposing side of the flip portion to enable viewing without the lens when the communication device is an open position and the auxiliary display on the opposing side of the flip portion can enable viewing with the lens when the communication device is in a closed position.
In a third embodiment, a method of incorporating an attachment lens to a camera in a camera phone in a flip style housing can include the steps of incorporating the camera within a first portion of the flip style housing, incorporating the attachment lens within a second portion of the flip style housing, and selectively aligning the camera with the attachment lens when the first portion pivots relative to the second portion. The attachment lens can be among a wide angle lens, a telephoto lens, a macro lens, and a filter. Note, the camera phone can further include at least one display and the method can further include the step of viewing an image on a main display on a flip portion of the camera phone or on an auxiliary display on an opposing side of the flip portion when the phone is in an open position and viewing another image using the attachment lens on the auxiliary display when the camera phone is in a closed position.
Other embodiments, when configured in accordance with the inventive arrangements disclosed herein, can include a system for performing and a machine readable storage for causing a machine to perform the various processes and methods disclosed herein.
While the specification concludes with claims defining the features of embodiments of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the figures, in which like reference numerals are carried forward.
Most phone cameras are of fixed focal length. An additional lens(es) is required to change the focal length so that a wider field of perspective can be taken. In accordance with an embodiment of the invention, changing the focal length can be achieved by incorporating an additional lens on one of the flip sides of a camera phone having a flip style or clam shaped housing. More specifically, referring to
Operationally, during a regular picture taking mode as shown in
To avoid vignetting over all the field angles of the camera, the aperture of the converter lens 14 can be larger than the primary lens of the camera 12. Note, most wide angle converters are “reverse telephoto”, with a negative lens followed by a positive lens, or combinations thereof where:
Magnification =−F1/F2, where F1 can be the focal length of the positive lens and F2 can be the focal length of the negative lens.
If F1=−F2/2, then M=0.5×
An afocal optical system can be used to provide a robust flip lens design. To provide further proof of concept, an imager placed at the exit pupil of an afocal optical system would maintain a focused spot as an image (or lens) shifts through rays of the same angle. In this regard, afocal systems are somewhat shift invariant.
An aperture is a physical stop in the system. The entrance pupil is the image of the aperture in object space, and the exit pupil is the image of the aperture in image space. The exit pupil of the converter lens 14 can align with the entrance pupil of the camera 12. Vignetting is a clipping of the light bundle due to field angle or misaligned apertures. The camera pupil should be able to shift within the converter pupil through all field angles.
The amplitude and phase of light rays are path dependent through an optical system. These typically degrade away from the center of the optical axis (0,0). Optical path difference plots can show increasing waves of aberration away from the origin and its color dependency. A converter lens 14 should be designed to have slow varying aberrations in the pupil and be color corrected.
If the attachment 14 is a wide angle converter lens, then good imaging can be achieved using an afocal lens that has no focusing power. Angular magnification, of approximately 0.8× to 0.5×, reduces the system focal length, and thus increases field of view. The exit pupil of the converter lens 14 should be coincident with the entrance pupil of the imager of the camera 12. Again, the converter pupil should be larger than the camera pupil to accommodate the expected de-centering tolerance and minimize vignetting. To avoid converter lens aberrations, the lens 14 should be slow varying across the pupil region where shift is expected and should be well color corrected.
Referring to
In light of the foregoing description, it should be recognized that embodiments in accordance with the present invention can be realized in hardware, software, or a combination of hardware and software. In light of the foregoing description, it should also be recognized that embodiments in accordance with the present invention can be realized in numerous configurations contemplated to be within the scope and spirit of the claims. Additionally, the description above is intended by way of example only and is not intended to limit the present invention in any way, except as set forth in the following claims.
