摘要:
A laser light beam generated from a light source is divided by a diffraction grating into a plurality of light beams, i.e., a single main beam to be used for recording information and plural auxiliary beams distributed on two imaginary straight lines crossing each other. One of the straight lines extends parallel to tracks of a recording medium. The resultant divided beams are converged to be irradiated onto a recording medium, and reflected components, from the recording medium, of the beams are received by corresponding light receiving elements. Thus, the main and auxiliary beams distributed on one of the two imaginary straight lines are used to perform focusing and tracking. Further, one of the two auxiliary beams distributed on the other straight line are used to determine whether a track where information is to be recorded is a blank area or not, and the other of the auxiliary beams is used to verify whether the information has been recorded correctly.
摘要:
In an optical information recording and reproducing apparatus, information is recorded or reproduced by moving a recording medium relative to an optical head. In order to execute information recording onto the medium in the course of the relative movement involving acceleration and deceleration, the generation timing and intensity of a light beam to be generated in correspondence with the information to be recorded are controlled in response to a varying speed of the relative movement so that data pits to be formed in the recording medium can be standardized in pitch and size irrespective of the relative movement speed. Also, in order to permit information reproduction from the medium in the course of the relative movement involving acceleration and deceleration, reproduction timing of data read by the optical head is set in synchronism with variation in the relative movement speed so that the data can be reproduced at proper timing irrespective of the relative movement speed. With such arrangements, there can be achieved a highly increased information recording/reproduction speed, extended information recording area, reduced size and cost of the apparatus, and reduced power consumption in the apparatus.
摘要:
A position detector detects a relative position of an optical head to a recording medium, and on the basis of the thus-detected relative position, a position detection signal is generated in response to movement of a light beam over a predetermined distance. Then, in response to the position detection signal, a comparison is made between the number of track crossing counted for the predetermined movement distance on the basis of reception of reflection of the light beam, and a predetermined reference value for the predetermined movement distance. Then, track crossing count compensation data is generated which corresponds to a difference between the counted number of track crossing and the reference value, and the counted number of track crossing is corrected by use of such compensation data.
摘要:
Controlled release pharmaceutical beads are provided having a multi-layered core and a multi-layered periphery. The core contains at least (A) an inner portion having a suitable organic acid and (B) a sustainably-acid-releasing coating thereover. The periphery contains at least (A) an inner portion having a mixture of at least (i) a pharmaceutical compound and (ii) a surface-active agent, and (B) a sustainably-drug-releasing exterior coating.
摘要:
An optical head for reading and/or writing information from and in an optical recording medium having an improved sensor structure for focusing and tracking error detections. A light beam is separated into a 0th-order diffraction light beam and .+-.1st-order diffraction light beams, and these light beams are impinged upon a recording track of the optical recording medium. The light beams reflected from the optical recording medium is separated into two different directions, and the tracking and focusing error detections are carried out with multi-segment optical sensors which are connected in a complementary manner. As a result, the influence of the tracking error on the focusing error detection is eliminated, and the linearity of the focusing error detection is improved.
摘要:
The present invention relates to an optical head for recording and playing back optical information, the optical head comprising an illumination system which shines three beams of light comprising 0-dimensional diffraction light, +1-dimensional diffraction light, and -1-dimensional diffraction light onto an optical information recording medium, and a photoreceiver system which receives three beams of reflected light from the recording medium; the photoreceiver system being provided with an edge mirror whereby, of the three beams of reflected light from the recording medium, approximately one half of the 0-dimensional diffraction light and all of the +1-dimensional diffraction light is received by a first photoreceiver diode, without being affected by the edge mirror, and the remaining approximately one half of the 0-dimensional diffraction light and all of the -1-dimensional diffraction light is reflected by the edge mirror and is received by a second photoreceiver diode; wherein a focusing control signal, a tracking control signal, and an information signal are obtained from an output from the first photoreceiver diode or the second photoreceiver diode, or from combined outputs from the first photoreceiver diode and the second photoreceiver diode.
摘要:
This device is an arrangement for detecting a signal for effecting a focus control of an optical head with respect to an optical information recording medium by making use of a reflected light beam from the optical information recording medium. On an optical path for a reflected light beam reflected from the recording surface of the optical recording medium, a photodetector is provided. This photodetector is composed of a plurality of elements arranged symmetrically in the transverse cross section of the light beam. Thus, an output of the outside element and an output of the inside element of the plural elements arranged in the transverse cross section of the light beam are used to detect a focus error, thus to utilize the signal detected for the focus control.
摘要:
A controlled release dosage form which consists essentially of a core containing a medicament; an inner coating layer composed of ethylcellulose and a hydrophobic substance; and an outer coating layer containing a medicament are disclosed. Said dosage form shows rapid increase in blood concentration of the medicament and at the same time maintains the high level of the blood concentration over a prolonged period time.
摘要:
A drying and fixing device for a recording paper comprises a heat drum and a feeding means cooperated thereto in order to dry and fix the recording paper having developed toner image by contacting the paper to the heat drum. The feeding means comprises feed rollers arranged at the forward direction, viewed in the direction of progress of the recording papers, in conact with the heat drum and feed rollers arranged to the heat drum with a certain distance at the backward direction, viewed in the direction of progress of the recording paper.