Daewoo Electronics Co., Ltd.

Yang-Oh Choi

Ki-tae Kim

An optical pickup system reproduces an information signal stored on an optical disk including a recording surface. The optical pickup system comprises an objective lens for focusing a light beam, having a P and an S polarizing components, on the recording surface, a first prism provided with an inclined and a side surfaces and a second prism provided with a side surface, wherein the second prism includes a light source for generating the light beam, a first detector and a first and a second 1/4 .lambda. plates, and a first prism includes a second detector and a polarizing film for transmitting only the P-polarizing component of the light beam to the recording surface. In the optical system, the first detector attached at the side surface of the second prism facing the second 1/4 .lambda. plate from outside, for receiving a part of the light beam impinging thereon and reflecting the remaining part of the light beam to the direction of the second 1/4 .lambda. plate, and the second detector fixed at the side surface opposite the first detector with respect to the center of the inclined surface of the first prism, for receiving the remaining part of the light beam.

Optical pickup system incorporated therein a polarizing film and a pair

An optical pickup system reads an information signal stored on a recording surface of an optical disk. The optical pickup system comprises a light source for generating a light beam, an optical detector for detecting the information signal off the optical disk, an objective lens for focusing a portion of the light beam impinged thereonto on the optical disk, and converging the light beam reflected by the optical disk on the optical detector and a knife edge provided with a parallelopiped base, made of a material transparent to the light beam, a first and a reflection layers formed on the parallelopiped base, wherein the second reflection layer reflects the portion of the light beam to the objective lens and the first reflection layer reflects the light beam reflected from the optical disk to the optical detector to thereby allowing the optical pickup system to read the information signals off the optical disk.

Knife edge method for use in an optical pickup system

An optical pickup system for selectively detects an information signal from, e.g., a pair of optical disks loaded on a disk tray, wherein each of the optical disks may have a different thickness. The optical pickup system includes a light source for generating a first and a second light beams having a different wavelength from each other, a first wavelength .lambda..sub.1, and a second wavelength .lambda..sub.2, and a beam splitter provided with a first and a second parts, wherein the first light beam impinging onto the first part is partially reflected to the first optical disk, and the second light beam impinging onto the second part is partially reflected to the second optical disk, thereby allowing the optical pickup system to detect an information signal from the respective optical disks.

Optical pickup system capable of selectively reading a multiple number

Disclosed is an optical pickup apparatus being manufactured with ease and utilizing the intensity of a laser beam effectively. The optical pickup apparatus comprises a polygonal prism having an upper surface, an incline surface, and a bottom surface. A laser beam emitted from laser source is reflected by the incline surface of the prism and is converged on an optical disc. Then, the reflected laser beam reflected by the optical disc is transmitted through the incline surface of the prism and is reflected by a Fresnel lens at the bottom surface of the prism and finally is focused on the photodetector. The optical pickup apparatus records and reproduces information on and from the optical disc and performs as a focusing servo and a tracking servo of the objective lens by utilizing data of the reflected information beam received by the photodetector.

Optical pickup apparatus

Beams generated from first and second laser light sources are reflected by a beam splitter to proceed toward an optical disc. The laser beams focus onto the optical disc via a selective light-transmitting part installed in front of the optical disc and an objective lens. The selective light-transmitting part is formed by an inner circular part for transmitting only the laser beam of first wavelength and a peripheral part for transmitting only the laser beam of second wavelength. The beam having transmitted through the inner circular part forms the larger beam spot on the disc while that having transmitted through the peripheral part forms the smaller beam spot, so that double beam focuses of different sizes can be formed by a single optical pickup device.

Optical pickup device for reproducing discs of two types with different

An optical pickup system reads an information signal stored on a recording surface of an optical disk. The optical pickup system comprises a light source for generating a light beam including a P and an S polarization component with a wavelength .lambda..sub.1, a 1/4.lambda. plate for changing the polarization component of the light beam transmitted therethrough, an optical detector for detecting the information signal off the optical disk, an astigmatic lens for generating an astigmatic aberration when a light beam transmits therethrough and a beam splitter, provided with a base and a phase layer, wherein the phase layer is formed by coating a first and a second material alternatively for reflecting each of the polarized light components into different directions, respectively, and the refractive index of the first material for the P-polarized light component is different from that of the second material for the S-polarized light component, thereby allowing the optical pickup system to read the information signals off the recording surface.

Optical pickup system incorporating therein a beam splitter having a

A beam generated from a laser light source are reflected by a beam splitter to proceed toward an optical disc. The beam focus onto the optical disc via a selective light-transmitting part installed in front of the optical disc and an objective lens. The beam is totally transmitted through an inner circular portion of the selective light-transmitting part and half transmitted through a peripheral portion of the selective light-transmitting part. The beam transmitted through the inner circular portion forms the larger beam spot on the disc while the beam transmitted through the peripheral portion forms the smaller beam spot, so that spherical aberration to be occurred due to change of the thickness of the optical disc is minimized by using the beam with smaller numerical aperture which has transmitted through the inner circular portion of the selective light-transmitting part.

An optical pickup system reads an information signal from stored on a recording surface of an optical disk. The optical pickup system includes a light source for generating a light beam including a P and an S polarization component with a wavelength .lambda..sub.1, a 1/4.lambda. plate for changing the polarization component of the light beam transmitted therethrough, an optical detector for detecting the information signal off the optical disk, and a beam splitter, provided with a first and a second surface, the first surface being capable of reflecting one of the polarization components to the optical disk through the 1/4.lambda. plate and transmitting the light beam reflected from the optical disk changed its polarization component by passing through the 1/4.lambda. plate to the second surface being capable of reflecting the light beam impinging thereon to the detecting means, thereby allowing the optical pickup system to read the information signals off the recording surface.

Compact sized optical pickup system

An optical pickup system for regenerating information stored on an optical disk including a pair of recording surfaces thereon, is provided with a pair of light sources, a detector, an objective lens, a signal detection unit, and a beam splitter having a first and a second recording surface. In this system, when the first light source is used for reproducing an information signal on the first recording surface of the optical disk, the first light beam transmitted through the second surface of the beam splitter is used for detecting the focusing error signal of the first recording surface of the optical disk. When the second light source is used for detecting the focusing error signal of the second recording surface of the optical disk, the second light beam reflected from the second surface of the beam splitter is utilized for reproducing an information signal on the second recording surface with the first light source turned off.

Pickup head having two laser light sources for separately reading an

An optical pickup system reads an information signal from stored on one of a first and a second optical disks alternatively to be loaded on a disk tray, wherein each of the optical disks may have a different thickness. The optical pickup system includes a light source for generating a first and a second light beams having a different wavelength from each other, a first wavelength .lambda..sub.1, and a second wavelength .lambda..sub.2, and an objective lens provided with a first and a second parts, wherein the surface of the first part is coated with a first dielectric film capable of transmitting only the first light beam emitted from the light source, whereas the surface of the second part is coated with a second dielectric film capable of transmitting only the second light beam, but totally reflecting the other light beams impinging thereon, thereby allowing the optical pickup system to detect an information signal from the respective optical disks.

Optical pickup system for selectively reading a multiple number of

An optical pickup system for reading information stored on a first or a second optical disk, each of the optical disks having a different thickness and selectively loaded on a disk tray, is provided with a light source for generating a first or a second light beam depending on the optical disk selectively loaded, each of the first and the second light beams having a different wavelength from each other, .lambda..sub.1, .lambda..sub.2, a knife edge, an optical device including a first and a second parts, an objective lens and a detector. In the above system, if one of the optical disks is selected to be loaded on a disk tray, the light source selects a light beam from the first and the second light beams based on the thickness of the selected optical disk. The knife edge reflects a portion of the selected light beam to the corresponding part of the optical device and the objective lens focuses the portion of the selected light beam transmitted through the selected optical disk, wherein the corresponding part of the optical device is capable of transmitting the selected light beam. The light beam reflected from the selected optical disk is converged on the detector and the corresponding part of the optical device, thereby allowing the optical pickup system to read the information off the selectively loaded optical disk.

Optical pickup system for reading optical disks of different thicknesses

A both-sided optical disc player for recording/reproducing information on a both-sided disc includes a disc deck having a turntable being shaft-supported by a spindle motor to be rotated for driving the disc and an optical pickup slidably connected on the upper portion of the disc deck. A disc tray guides the disc to the turntable for loading the disc onto the disc deck. A clamp apparatus pressively supports the both-sided disc on the turntable. The both-sided disc seated on the turntable is transferred up and down centering about the optical pickup by a transfer apparatus to reproduce respective sides of the both-sided disc. Thus, trembling of the optical pickup is significantly reduced to realize stable recording/playback operations.

Both-sided optical disc player capable of transferring a both-sided disc

Optical pickup apparatus utilizing a polygonal prism

Disclosed is an optical pickup having simplified constitution. A light source for radiating laser beam for reading an optical disc is comprised. A beam splitter for separating the laser beam radiated from the light source into transmitting light and reflecting light and for separating light from the optical disc into transmitting light and reflecting light is provided. Installed is an objective lens for converging light from the beam splitter to form a focus on the optical disc and for forwarding light from the optical disc to the beam splitter. A micro fresnel lens attached on one side of the beam splitter is included. The micro fresnel lens generates astigmatism and converges the incident light from the beam splitter. A photodetector receives light from the micro fresnel lens, reproduces information recorded on the optical disc and detects a focus error. The manufacture of the optical pickup is advantageous and the product has improved quality.

Optical head with a micro fresnel lens integrated on a beam splitter

An integrated optical pickup system for reproducing an information signal stored on a recording surface of an optical disk is comprised of a first optical glass substrate, integrated with a semiconductor laser, a reflection collimating lens, a transmission off axis diffractive object lens and a reflection layer, for impinging a converged light beam onto the optical disk and collimating the converged light beam after being reflected from the recording surface and a second glass substrate, integrated therein with a twin focusing beam splitter and a photo detector, for guiding the collimated light beam from the first glass substrate to the photo detector, thereby allowing the integrated optical pickup system to reproduce the information signal off the recording surface of the optical disk.

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Seoul, South Korea

Yang-Oh Choi