摘要:
An optical disk has a lead-in region provided at the inner circumference side and a user region provided at the outer circumference side. Pit string 3 of pits of different depths is formed in the lead in region. Light beam reflected from the pit string is detected by detector and TPP and RF signals are output by differential amplifier and addition amplifier. A ternary signal is restored from pits based on the TPP and RF signals. Information is recorded by pits of the same depth in the user region. Recording information in the depth direction in the lead-in region increases the recording capacity thereof. The information recorded in the depth direction in the lead-in region cannot be transferred to a user region of another optical disk.
摘要:
An optical disk has a lead-in region provided at the inner circumference side and a user region provided at the outer circumference side. Pit string 3 of pits of different depths is formed in the lead-in region. Light beam reflected from the pit string is detected by detector and TPP and RF signals are output by differential amplifier and addition amplifier. A ternary signal is restored from pits based on the TPP and RF signals. Information is recorded by pits of the same depth in the user region. Recording information in the depth direction in the lead-in region increases the recording capacity thereof. The information recorded in the depth direction in the lead-in region cannot be transferred to a user region of another optical disk.
摘要:
An optical disk has a lead-in region provided at the inner circumference side and a user region provided at the outer circumference side. Pit string 3 of pits of different depths-is-formed-in-the-lead-in-region. Light beam reflected from the pit string is detected by detector and TPP and RF signals are output by differential amplifier and addition amplifier. A ternary signal is restored from pits based on the TPP and RF signals. Information is recorded by pits of the same depth in the user region. Recording information in the depth direction in the lead-in region increases the recording capacity thereof The information recorded in the depth direction in the lead-in region cannot be transferred to a user region of another optical disk.
摘要:
An optical device to control the output power of a laser on recording and reproduction without expensive high-speed circuits is provided. The optical disk device of the present invention comprises monitor portion for monitoring the power of laser light, averaged light quantity calculating portion for calculating the averaged light quantity of the power of the laser light, memory portion for memorizing the averaged light quantity, error quantity calculated portion for calculating the difference between the output signals of the averaged light quantity calculating portion and the memory portion, and laser power control portion for controlling the power of the laser light in response to the output signal from the error quantity calculating portion.
摘要:
On an optical disc including a substrate on which pits having at least two different depths are formed, main information is recorded by the shape of the pits and additional information is recorded by the depth of the pit. It is possible to reverse polarity of a tangential push-pull signal dependent on the depth of the pit, and therefore it becomes possible to record information utilizing the depth of the pit. This improves recording density of the optical disc. Further, when information of the optical disc is to be copied, the information recorded by the depth of the pit cannot be copied. Therefore, unauthorized reproduction can be prevented.
摘要:
An optical recording medium capable of obtaining a large reproduced signal from the recoded mark, a large reproduced signal of a pre-pit and a large tracking signal both in an area of the grooves and an area of the pre-pits, which provides a sufficient time allowance for switching tracking to that suitable for the area of the grooves or to that suitable for the area of the pre-pits. An optical recording medium comprising a substrate whereon tracks each comprising at least of writable grooves and pre-pits deeper than or equal to the grooves are formed and areas of a relatively shallow pits are each provided between an area of the deep pits and an area of the grooves. The depth Dg of the grooves, the depth Dsp of the shallow pits and the depth Ddp of the deep pits satisfy the following conditions: Dg
摘要:
On an optical disk, a string of a plurality of pits having two different depths is formed. Quantity of light reflected from the pit string is detected by a photoreceptor element, and based on the detected quantity of reflected light, a pit depth detecting unit detects depth of each pit. Based on the detected quantity of reflected light, a servo signal generating unit generates a tracking servo signal. An output control unit supplies the generated tracking servo signal when a pit of such depth that is to be reproduced is tracked, and holds and supplies an immediately preceding tracking servo signal when a pit of different depth is being tracked, based on the result of detection by the pit depth detecting unit.
摘要:
On an optical disc including a substrate on which pits having at least two different depths are formed, main information is recorded by the shape of the pits and additional information is recorded by the depth of the pit. It is possible to reverse polarity of a tangential push-pull signal dependent on the depth of the pit, and therefore it becomes possible to record information utilizing the depth of the pit. This improves recording density of the optical disc. Further, when information of the optical disc is to be copied, the information recorded by the depth of the pit cannot be copied. Therefore, unauthorized reproduction can be prevented.
摘要:
An electronic device is provided which includes a base, a through-electrode that passes through the base and from which an insulating material on an end face thereof is removed by polishing, a circuit pattern that is formed on an end face of the through-electrode, an electronic component that is disposed via an internal wiring formed on the circuit pattern, an electrode pattern that is formed on the surface of the base opposite to the surface on which the electronic component is disposed and that is connected to the other end face of the through-electrode, an external electrode that is formed on the electrode pattern, and a cap that is bonded to the base so as to protect the electronic component on the base.
摘要:
An air filter assembly has a fan, pre-filter, a main filter, and a control circuit which generates various signals to the user as to when the pre-filter and the main filter should be replaced. The control circuit detects when the pre-filter should be replaced from two conditions: a first pre-filter replacement condition based decreased air flow, and a second pre-filter replacement condition based on cumulative operating time. The control circuit detects when the main filter should be replaced based on a formula containing a number of the occurrences of the first pre-filter replacement condition and a number of occurrences of the second pre-filter replacement condition. The control circuit also detects a main filter replacement condition based on cumulative operating time of main filter. The main filter can have a fuse that is blown when the main filter should be replaced.