摘要:
An optical scanning device incorporating a compound objective lens 10 and a radiation detector 31 is described for reading an optical record carrier 1 in which the optical record carrier 1 is provided with a transparent layer 2. The thickness of the transparent layer 2 and the effective radius of the detector 31 are adapted such that the signal-to-noise ratio of the device is significantly improved and/or local heating of an air gap below an air slider is reduced. The optical record carrier is provided with a lubricant to facilitate the use of a slider optical head 40.
摘要:
The present invention discloses an optical device comprising a container enclosing an insulating liquid (A) and an electrically susceptible liquid (B), the insulating liquid (A) and the electrically susceptible liquid (B) being immiscible and being in contact with each other via an interface (14), at least one of the liquids (A; B) being at least partially placed in a light path through the container. The optical device further comprises heating means (2, 12, 20) that preferably are responsive to a temperature sensor (30) for heating the insulating liquid (A) and the electrically susceptible liquid (B). Consequently, an optical device is obtained in which the influence of the temperature dependence of the physical properties of the insulating liquid (A) and the electrically susceptible liquid (B) on the behaviour of the optical device is reduced, thus yielding an optical device with improved optical characteristics at low temperatures.
摘要:
In an image sensor incorporating a variable focus lens of the electrowetting type, means are provided for reducing or substantially eliminating the occurrence of ghost images. A variable focus lens of the above-mentioned type comprises a housing (5) provided with a first fluid (A) and an axially displaced second fluid (B), the two fluids being non-miscible, in contact over a meniscus (14) and having different indices of refraction. First and second electrodes (2,12) are provided and the shape of the meniscus (14) is controllable in dependence on the application of a voltage between the first and second electrodes (2,12). Various methods of reducing or substantially eliminating the occurrence of ghost images are prepared, including the alteration of the optical properties of an inner and/or outer wall of the housing (5), to reduce the reflectivity thereof, provision of means in the image sensor to intercept ghosting and appropriate selection of the material or combination of materials of which the housing (5) is formed.
摘要:
An achromatic electrowetting lens is provided. This is achieved by a particular choice of the parameters n, n2, V, and V2, wherein n is the refractive index and V is the Abbe number. By fulfilling the relations: Formula (I) an achromatization of the electrowetting lens is achieved.
摘要:
An electrowetting device comprises a variable element (28) and a control system (11) for the variable element (28), wherein the control system (11) is adapted to provide an asymmetric voltage waveform to the variable.
摘要:
A variable lens (100; 200; 220; 240; 250; 300; 350) comprises a chamber (125), with an optical axis (90) extending through the chamber (125). The chamber (125) contains a first fluid (130) and a second fluid (140) in contact over a meniscus (150)>extending transverse the optical axis (90). The perimeter of the meniscus (150) is fixedly located on an internal surface (120) of the chamber (125). The fluids (130, 140) are substantially immiscible and have different indices of refraction. A pump (110) is arranged to controllably alter the shape of the meniscus (150) by altering the relative volume of each of the fluids (130, 140) contained within the chamber (125).
摘要:
An electrowetting module (20) comprises a fluid chamber (8) which contains a first fluid (A) and a second fluid (B), which are separated by an interface (14), and means to (16,17) exert a force on at least one of the fluids to change the position and/or shape of the interface. By providing at least one of the fluids with a compound having at least one aromatic, non-fused, residue, the performance of the module can be enhanced. For example the optical power of an electrowetting lens (30) can be increased.
摘要:
The invention relates to an optical disc drive that comprises rotating means, defining a rotating axis for an optical disc, and an optical scanning device, for scanning said optical disc with a light beam. These optical scanning means themselves comprise a first light source, for producing said first light beam, focusing means, provided between the first light source and a focusing point on an information layer on the disc, an optical detector, for receiving a first backward beam reflected from said information layer, and a second light source, for producing a second light beam also transmitted to said focusing means and for measuring tilt from the position, on said optical detector, of a second spot corresponding to a second backward beam obtained after reflection of the second light beam on the information layer. According to the invention, a diffractive structure, provided with diffracting elements for substantially refocusing the returning second beam onto the detector, is provided between said focusing point and said optical detector. This diffractive structure, consisting of a series of ring-shaped prisms, is attached either to one surface of a servo-lens positioned just before said optical detector, or to one surface of an objective lens used as focusing means, or to a separate plate. The diffractive structure may also be approximated by a step-wise structure.
摘要:
A light control element (100) is disclosed having a first chamber (110) encapsulating a first liquid crystal based light absorbing material (112; 114) being switchable from a first orientation in which said material (112; 114) predominantly absorbs light having a first polarization direction to a second orientation in which said material (112; 114) is substantially transparent and that further has a second chamber (120) encapsulating a second liquid crystal based light absorbing material (122; 124) being switchable from a first further orientation in which said material (122; 124) predominantly absorbs light having a polarization direction substantially perpendicular to the first polarization direction to a second further orientation in which said material (122; 124) is substantially transparent. A plurality of electrodes is present for switching the orientations of the first and second light absorbing materials. Consequently, a polarization independent light control element (100) is obtained.
摘要:
An optical scanning device which is compatible with both multi-layer and single layer disc formats, and which alleviates lens design requirements by providing a dual lens system and by making, say, lens OL0 compatible with DVD (as well as layer L0 of the dual layer format) and lens OL1 compatible with CD (as well as layer L1 of the dual layer format). Thus the two lens designs only need to work at two different wavelengths, and the device achieves compatibility with three different optical record carrier formats, but the amount of spherical aberration in respect of each lens part only needs to be matched precisely with respect to two formats in one of a number of known ways.