Unlock instant, AI-driven research and patent intelligence for your innovation.

Information reproduction apparatus

A technology for information reproduction and information recording, which is applied in beam guiding devices, information storage, recording information storage, etc., and can solve the problems of insufficient S/N ratio and complex light receiving optical system.

Inactive Publication Date: 2006-04-26
HITACHI MEDIA ELECTORONICS CO LTD
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to adapt to this multi-recording method specification, in order to construct an optical disc recording / reproducing device that can be used universally and interchangeably, the light receiving optical system of the optical head becomes complicated, and the loss of light quantity caused by the increase in the number of optical components becomes a problem. , also becomes the cause of insufficient S / N ratio

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Information reproduction apparatus
  • Information reproduction apparatus
  • Information reproduction apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0072] (An additional optical system is installed on the RF signal detection surface)

[0073] use Figure 1~Figure 20 An example of the configuration of an optical information reproducing device equipped with a dedicated RF signal detection surface according to the present invention will be described.

[0074] First, use Figure 5 with Figure 14 A configuration example of the light receiving portion of the optical system of the information reproducing device according to the present invention will be described.

[0075] Figure 5 It is one of the three-spot methods and corresponds to an example in which the detection surface on the light receiving element that detects the TR signal by the differential push-pull method is connected to the nearby photocurrent amplifier. The light irradiated from the laser light source to the information recording medium is modulated in light intensity according to the recorded information, and is reflected by the information recording medium. The ...

Embodiment 2

[0089] (RF signal amplification using AC amplifier)

[0090] use Figure 4 ~ Figure 8 The structure and effect of the case where the AC amplifier is used as the photocurrent amplifier according to the present invention will be described.

[0091] In the prior art, as mentioned above, for DC amplifiers, based on the signal potential at which the amount of light is zero, in order to correctly amplify changes in the amount of DC light, it is generally used Figure 4 (a) With such a differential amplifier, when the amplifier noise is limited, the S / N ratio deteriorates by about 6 dB due to the differential amplification.

[0092] For this, if you use Figure 4 (b) Such an AC amplifier can suppress the generation of amplifier noise to a minimum. Amplifier noise and Figure 4 (a) Compared with the improvement of about 6dB. For the AC amplifier, because it is combined with AC, it will not amplify the change in DC voltage. However, since a circuit for voltage conversion or level shifting ...

Embodiment 3

[0103] (RF synthesis reproduction system 1)

[0104] Next, use figure 1 as well as Figure 8~Figure 16 A configuration example and effect in a case where the RF amplified signal of the AC amplifier according to the present invention and the amplified signal of the DC amplifier of the quarter-divided photodetector are used to obtain a composite RF signal with lower noise will be described.

[0105] figure 1 It is an optical information reproducing device composed of the light receiving part of the optical head and the circuit near the light receiving part (optical head). A diffraction grating is installed in front of the light receiving element chip to split the light beam incident on the light receiver into two or more beams. figure 1 Corresponds to TR signal detection and AF signal detection using the 3-spot method. Will be used later Picture 20 The overall device structure will be described.

[0106] The light irradiated on the light receiving element is divided by the diff...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

Using a multi-wavelength, multi-standard compatible optical disc device, it is desired to construct a light-receiving optical system and a circuit system capable of improving the S / N ratio at low cost. An RF-dedicated light receiving surface is provided, and the S / N ratio is improved by band combining with signals from other light receiving surfaces. In beam splitting, the adjustment accuracy is greatly eased by using a diffraction grating. An AC amplifier can be used as a photocurrent amplifier for RF.

Description

Technical field [0001] The present invention relates to an optical disc device, an optical disc medium, and an optical information storage device that uses light to record / reproduce information on a recording medium. In particular, it relates to solving the problem of the signal quality of the reproduced signal, using a high-density optical disc using blue / blue-violet light or An information reproducing device with multiple light sources with different wavelengths, compatible with multiple methods / standards, and high-speed / high-density recording. Background technique [0002] Increasing the density of information recording on optical recording media represented by optical discs and the speeding up of information reading speed are progressing. Along with this increase in density and speed, there has been a problem of degradation of the detection signal quality represented by the signal-to-noise ratio (S / N ratio). [0003] In recent years, the main reason for the insufficient S / N r...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G11B7/135G02B5/18G11B7/09
CPCG11B7/1275G11B7/131G11B7/1353G11B7/1381G11B2007/0006
Inventor 一色史雄渡边康一岛田坚一黑川贵弘
Owner HITACHI MEDIA ELECTORONICS CO LTD