Recording/reproducing apparatus including an optical pickup having an objective lens compatible with a plurality of optical disk formats

A recording and or reproducing apparatus compatible with at least two substrates having respectively different thicknesses and information recording surfaces which store information, the recording and/or reproducing device comprising:

• an objective lens comprising
• an inner area, an annular lens area and an outer area centered at a vertex, the annular lens area having a ring shape and dividing the inner area from the outer area,
• wherein the inner area, the annular lens area and the outer area have aspherical surface shapes so as to focus light transmitted through the inner area and the outer area into a single light spot by which the information is read from the information recording surface of a first one of the at least two substrates which has a first thickness and to scatter the light transmitted through the annular lens area formed between the inner area and the outer area so that the scattered light is not focused on the information recording surface of the first substrate, when the first substrate is to be used, and so as to focus the light transmitted through the inner area and the annular lens area into the single light spot by which the information is read from the information recording surface of a second one of the at least two substrates which has a second thickness greater than the first thickness and to scatter the light transmitted through the outer lens area so that the scattered light is not focused on the information recording surface of the second substrate, when the second substrate is to be used;
• and
• a processing unit which processes an information signal to control the light transmitted to the objective lens, and to process the light passed through the objective lens.

A recording and/or reproducing apparatus device in an optical device and compatible with disks having different thicknesses, the recording and/or reproducing apparatus comprising:

• an optical pickup device comprising:
• a light source to emit a light,
• an objective lens, facing one of the disks which is placed in the optical device, having a light passing region divided into inner, annular lens and outer regions respectively corresponding to a near axis area, an intermediate axis area and a far axis area of incident light, wherein curvatures of the inner and outer regions are optimized for the one disk if the one disk has a first thickness, a curvature of the annular region is optimized for the one disk if the one disk has a second thickness greater than the first thickness, and the curvature of the inner region sufficiently focuses light together with the light passing through the annular region so as to read data on the one disk if the one disk has the second thickness,
• a photo detector for detecting the light reflected from the one disk, and
• a separation unit to separate the incident light transmitted from said light source from the reflected light reflected by the one disk;
• and
• a processing unit to process an information signal to control the incident light generated by said light source to process the detected light from said light detector.

A recording and/or reproducing apparatus device in an optical device and compatible with disks having different thicknesses, the recording and/or reproducing apparatus comprising:

• an optical pickup device comprising:
• a light source to emit a light,
• an objective lens, facing one of the disks which is placed in the optical device, having a light passing region divided into inner, annular lens and outer regions respectively corresponding to a near axis area, an intermediate axis area and a far axis area of incident light, wherein curvatures of the inner and outer regions are optimized for the one disk if the one disk has a first thickness and a curvature of the annular region is optimized for the one disk if the one disk has a second thickness greater than the first thickness,
• a photo detector for detecting the light reflected from the one disk, and
• a separation unit to separate the incident light transmitted from said light source from the reflected light reflected by the one disk;
• and
• a processing unit to process an information signal to control the incident light generated by said light source to process the detected light from said light detector,
• wherein the inner region has a numerical aperture value NA according to the following equation:
• 0.8 λ/NA˜spot size;
• wherein λ is a wavelength of the light emitted from the light source and the spot size is a size of a spot that the light passing through the objective lens forms on the one disc.

A recording and/or reproducing apparatus device in an optical device and compatible with disks having different thicknesses, the recording and/or reproducing apparatus comprising:

• an optical pickup device comprising:
• a light source to emit a light,
• an objective lens, facing one of the disks which is placed in the optical device, having a light passing region divided into inner, annular lens and outer regions respectively corresponding to a near axis area, an intermediate axis area and a far axis area of incident light, wherein curvatures of the inner and outer regions are optimized for the one disk if the one disk has a first thickness and a curvature of the annular region is optimized for the one disk if the one disk has a second thickness greater than the first thickness,
• a photo detector for detecting the light reflected from the one disk, and
• a separation unit to separate the incident light transmitted from said light source from the reflected light reflected by the one disk;
• and
• a processing unit to process an information signal to control the incident light generated by said light source to process the detected light from said light detector,
• wherein the annular lens region has an aspherical surface shape by which the annular lens region corrects optical aberration of the light from the light source passing therethrough at a position of a focal point of the inner region.

A recording and/or reproducing apparatus device in an optical device and compatible with disks having different thicknesses, the recording and/or reproducing apparatus comprising:

• an optical pickup device comprising:
• a light source to emit a light,
• an objective lens, facing one of the disks which is placed in the optical device, having a light passing region divided into inner, annular lens and outer regions respectively corresponding to a near axis area, an intermediate axis area and a far axis area of incident light, wherein curvatures of the inner and outer regions are optimized for the one disk if the one disk has a first thickness and a curvature of the annular region is optimized for the one disk if the one disk has a second thickness greater than the first thickness,
• a photo detector for detecting the light reflected from the one disk, and
• a separation unit to separate the incident light transmitted from said light source from the reflected light reflected by the one disk;
• and
• a processing unit to process an information signal to control the incident light generated by said light source to process the detected light from said light detector,
• wherein:
• a surface of the annular lens region forms a step difference with a surface of one of the inner and outer regions,
• the surface of the annular lens region forms the step difference with the surface of the inner region,
• the step difference is a value such that a light path difference between the light passing through the inner region and the light passing through the annular lens region is an integer multiple of a wavelength of the light emitted from the light source.

A recording and/or reproducing apparatus compatible with different types of optical memory media, the recording and/or reproducing apparatus comprising:

• an objective lens having a plurality of portions having different optical characteristics, wherein one of said plurality of lens portions focuses said light onto one of said optical memory media independent of the type of said one optical memory medium;
• wherein said plurality of lens portions include
• a first portion to focus a light emitted from a light source onto said one optical memory medium independent of a thickness of said one optical memory medium,
• a second portion to focus said light emitted from the light source onto said one optical memory medium if said optical memory medium has a first predetermined thickness,
• a third portion to focus said light emitted from said light source onto said one optical memory medium if said optical memory medium has a second predetermined thickness which is different from said first predetermined thickness, and
• a surface of the second portion forms a step difference with a surface of one of the first and third portions;
• and
• a processing unit to process an information signal to control the light emitted from the light source, and to process the light passed through said objective lens.