| Patent application number | Description | Published |
|---|
| 20110157702 | DIFFRACTIVE OPTICAL ELEMENT AND OPTICAL DEVICE - In a diffractive optical element, first and second optical members are stacked, and a diffraction grating is formed at an interface between the first and second optical members. In the diffractive optical element, an absorption coefficient α (mm | 06-30-2011 |
| 20110235178 | DIFFRACTIVE OPTICAL ELEMENT AND OPTICAL DEVICE - A diffractive optical element includes first and second optical members which are stacked. A diffraction grating is formed at an interface between the first and second optical members. A plurality of pores are formed in the second optical member. | 09-29-2011 |
| 20110235180 | DIFFRACTIVE OPTICAL ELEMENT AND OPTICAL DEVICE - A diffractive optical element includes a first optical member having a first diffraction grating with a sawtooth cross section; and a second optical member which has a second diffraction grating having a sawtooth cross section and which has a refractive index different from that of the first optical member. In the diffractive optical element, the first and second optical members are stacked so that the first and second diffraction gratings closely contact each other. Arithmetical mean roughness of a diffraction surface of the first diffraction grating is set so as to fall within a predetermined range. | 09-29-2011 |
| 20110261459 | DIFFRACTIVE OPTICAL ELEMENT AND OPTICAL DEVICE - A diffractive optical element includes first and second optical members which are stacked. The first optical member includes a diffraction grating in which a plurality of raised portions each having a vertical surface and a surface inclined to the vertical surface are arranged. The second optical member includes a diffraction grating in which a plurality of recessed portions are arranged, to which the raised portions are fitted. The diffraction grating of the first optical member and the diffraction grating of the second optical member are in close contact with each other. A ridge portion of the raised portion defines a curved surface. A curvature radius R (μm) of the curved surface, a pitch P (mm) of the raised portions, and a refractive index difference Δn | 10-27-2011 |
| 20120182852 | OBJECTIVE LENS, OPTICAL HEAD, OPTICAL DISK APPARATUS, AND INFORMATION PROCESSING APPARATUS - An objective lens, an optical head, an optical disk apparatus and an information processing apparatus which can suppress deterioration of a focal spot caused by a drop in the diffraction efficiency are provided. An inner circumference area ( | 07-19-2012 |
| 20120207008 | Objective Lens Element and Optical Head Device Including the Same - An objective lens element having improved diffraction efficiency at least one of used wavelengths is provided. The objective lens element includes one surface including: a first region including an optical axis; and a second region surrounding the first region. A periodic first diffraction structure is formed on the first region, and a periodic second diffraction structure different from the first diffraction structure is formed on the second region. The objective lens element satisfies the following conditions. | 08-16-2012 |
| 20130223201 | OBJECTIVE LENS AND OPTICAL PICKUP DEVICE - An objective lens capable of converging light of a used wavelength with a satisfactory aberration on a recording medium is provided. An objective lens for converging light of a predetermined wavelength λ on a recording medium satisfies the following condition: |CML|+|CMF|<0.03λ, where CML is an amount of a generated third-order coma aberration per 1 degree of tilt of the objective lens, and CMF is an amount of a generated third-order coma aberration per 1 degree of tilt of off-axis light. | 08-29-2013 |
| 20140098656 | OPTICAL ELEMENT - An optical element has at least one surface divided into a plurality of regions and includes: a first region configured to converge light with a wavelength λ | 04-10-2014 |
| 20140146653 | OBJECTIVE LENS ELEMENT AND OPTICAL HEAD DEVICE INCLUDING THE SAME - An objective lens element having improved diffraction efficiency at at least one of used wavelengths is provided. The objective lens element includes one surface including: a first region including an optical axis; and a second region surrounding the first region. A periodic first diffraction structure is formed on the first region, and a periodic second diffraction structure different from the first diffraction structure is formed on the second region. The objective lens element satisfies the following conditions. | 05-29-2014 |
| 20140254345 | OBJECTIVE LENS, OPTICAL HEAD, OPTICAL DISK DEVICE, AND INFORMATION PROCESSING DEVICE - Assuming that third-order coma aberration per unit angle generated by tilt of BD ( | 09-11-2014 |
| 20140293766 | OPTICAL ELEMENT AND OPTICAL HEAD APPARATUS INCLUDING THE SAME - An optical element having compatibility among two or more wavelengths and having an excellent converging performance for light with each wavelength, and an optical head apparatus using the optical element are provided. An optical element according to the present disclosure has a first region including an optical axis and a second region formed around the outer circumference of the first region. The first region and the second region respectively have a first diffraction structure and a second diffraction structure each cyclically formed on an aspheric surface and having a step-like cross section. In the first region, the number of steps included between top portions of the first diffraction structure is different from the number of steps included between the optical axis and a top portion that is closest to the optical axis in the first diffraction structure. | 10-02-2014 |
