 Polarization independent wavelength tunable filter based on birefringence compensation |
| It is an object of the present invention to provide a tunable, polarization independent wavelength ... |
|
| Wavelength division multiplexer and demultiplexer |
| This invention is based on the observation that many filters have the characteristic property that ... |
|
| Tunable filtering device for optical communications |
| To solve the above problems, it is an objective of the present invention to provide a tunable ... |
|
| Wavelength selection switches for optical application |
| This invention is based on the observation that, by making use of filters that selectively passes ... |
|
| All-optical holographic code division multiple access switch |
| These shortcomings and other limitations and deficiencies are obviated in accordance with the ... |
|
| Method and apparatus for displaying three-dimensional images |
| What is claimed is: 1. A method for producing a three-dimensional image, comprising the steps of: ... |
|
| Lens array and method of making same |
| FIG. 4 is a flowchart illustrating a method 400 in accordance with an embodiment of the present ... |
|
| Optical signal processor, method of its control, method of its designing, and method of its production |
| The present invention has been accomplished in the light of the conventional technologies discussed ... |
|
| Method and system for equalizing PMD using incremental delay switching |
| OF THE PREFERRED EMBODIMENTS The present invention is a PMD compensator based upon delay elements ... |
|
|
Optical head and optical data recording and reproducing apparatus having the same
| Details |
Inventors: Hayashi, Hideki; Mizuno, Sadao; Ito, Noboru; Urairi, Kenichiro; Komma, Yoshiaki;
Assignee: Matsushita Electric Industrial Co., Ltd. (Kadoma, JP)
Primary Examiner: Huber; P. W.
Assistant Examiner:
Attorney, Agent or Firm: Renner, Otto, Boisselle & Sklar, P.L.L.
An optical head for reproducing data from first and second optical disks which are different from each other in at least one of a base material thickness and an available wavelength, includes: a first light source for emitting a first light beam, the first light beam being used for reproducing data from the first optical disk: an optical system designed to converge the first light beam onto the first optical disk in accordance with a base material thickness and an available wavelength of the first optical disk: and a second light source for emitting a second light beam, the second light beam being used for reproducing data from the second optical disk, wherein an optical path length between the second light source and the optical system is different from an optical path length between the first light source and the optical system, and wherein the optical system converges the second light beam onto the second optical disk. |
|
DETAILED DESCRIPTION According to one aspect of the invention, the optical head for reproducing data from first and second optical disks which are different from each other in at least one of a base material thickness and an available wavelength, includes: a first light source for emitting a first light beam, the first light beam being used for reproducing data from the first optical disk; an optical system designed to converge the first light beam onto the first optical disk in accordance with a base material thickness and an available wavelength of the first optical disk; and a second light source for emitting a second light beam, the second light beam being used for reproducing data from the second optical disk, wherein an optical path length between the second light source and the optical system is different from en optical path length between the first light source and the optical system, and wherein the optical system converges the second light beam onto the second optical disk.
According to another aspect of the invention, the optical data recording and reproducing apparatus includes an optical head for reproducing data from first and second optical disks which are different from each other in at least one of a base material thickness and an available wavelength, disk discriminating means for discriminating between the first and second optical disks, and drive means for driving the optical head based on a result of the discrimination obtained by the disk discriminating means, the optical head including: a first light source for emitting a first light beam, the first light beam being used for reproducing data from the first optical disk; an optical system designed to converge the first light beam onto the first optical disk in accordance with a base material thickness and an available wavelength of the first optical disk; and a second light source for emitting a second light beam, the second light beam being used for reproducing data from the second optical disk, wherein an optical path length between the second light source end the optical system is different from an optical path length between the first light source and the optical system, end the optical system is determined so that the second light beam is converged onto the second optical disk
|
| Related patents |
|
|
Device for optically scanning a recording medium by focusing the best focus or the paraxial focus to the information layer
It is an object of the invention to provide a device for optically scanning a record carrier, which has a simple construction and an improved utilisation of the optical ...
|
|
|
Objective lens for recording and reproducing for use in an optical information recording medium
An object of the invention is to make it possible that recording and reproducing by means of optical disks having different substrate thicknesses are conducted in a ...
|
|
|
Optical pickup used with both DVD and CD
The present invention has been made to solve above-mentioned problems and it is an object of the invention to provide an optical pickup of a compatible type which can be ...
|
|
|
Correction elements to lower light intensity around an optical axis of an optical head with a plurality of focal points
An object of the present invention is to provide a light head apparatus which can read information more stably by decreasing disadvantages of higher optical intensity at ...
|
|
|
Objective lens for optical pick-up head of optical disk drive
It is therefore the principle object of the present invention to provide an objective lens for optical pick-up head of optical disk drive devices capable of simplifying ...
|
|
|
Optical head
For solving the problem of the prior art, an optical head of the present invention comprises, light source, luminous flux splitting means for splitting radiation ...
|
|
|
Compound objective lens having two focal points
A first object of the present invention is to provide, with due consideration to the drawbacks of such a conventional objective lens having a focal point, a compound ...
|
|
|
Optical pickup device for reproducing discs of two types with different densities by double beam focuses of different sizes
Therefore, it is an object of the present invention to provide an optical pickup device capable of reproducing discs of two kinds having different densities by forming ...
|
|
|
Multiple focus lens, an optical head apparatus and an optical information recording-reproducing apparatus
In order to solve these and other problems, this invention aims to provide a multiple focus lens designed to substantially standardize the conditions for correction of ...
|
|
|
Polarizing plate and liquid-crystal display containing the same
What is claimed is: 1. A polarizing plate comprising: a protective film, 5 to 150 μm thick, composed of cyclic-olefin-based resin having an anchor coat agent ...
|
|
|
Optical Systems 
