JPS62184637A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To detect the dirt on an objective lens by comparing a reference signal and an output signal of a light read sensor when the light irradiated from the objective lens of an optical head is received again by the objective lens after the light is reflected in the reflecting face. CONSTITUTION:The reflecting face 3 is arranged in a movable range of the optical head 1 at a location where the face is not in contact with a disk medium 2. The light irradiated from a light source of the optical head 1 via the objective lens 11 is reflected in the reflecting face 3 and made again incident on the objective lens 11, the change in the luminous quantity is converted into an electrical signal by a light read sensor 12 and detected. Further, an output of the light read sensor 12 and an output of a reference voltage generator 21 are inputted by a comparator 22, from which a comparison signal output A is obtained. The reduction in the luminous quantity by >=-20% is detected by the inversion of the output of the comparison signal output A and the detected point of time is used as a time when the dirt of the objective lens 11 is to be cleaned.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is for optically transmitting information to optical discs and optical discs used for digital audio discs, video disc image files, data files, etc. The present invention relates to an optical information recording and reproducing device for recording and reproducing.

[Conventional technology]

Conventionally, optical information recording and reproducing apparatuses have not been provided with means for detecting dirt on the objective lens of the head.

[Problem that the invention seeks to solve]

Conventional optical information recording and reproducing devices cannot detect dirt on the objective lens of the optical head in advance, and the dirt on the objective lens of the optical head deteriorates information recording and reproducing characteristics, making normal recording and playback impossible. However, it is not possible to detect when the objective lens should be cleaned, and the dirt on the objective lens may prevent normal recording and reproduction of information.

[Means for solving problems]

The optical information recording/reproducing apparatus of the present invention includes an optical head having an optical reading sensor and an objective lens that emits light from a light source to a disk medium, receives light from the disk medium, and sends the light to the optical reading sensor; It is configured to include a reflecting surface that can be placed on the optical axis of the light emitted from the objective lens, and a comparator that compares the output signal of the optical reading sensor with a reference signal.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of an optical recording/reproducing apparatus of the present invention. FIG. 1 shows a state in which the optical head 1 is in positions @a and b. Position #a indicates when the optical head 1 is located below the disk medium 2 and is recording and reproducing information on the disk medium 2 by 5%.

The reflective surface 3 is arranged in a movable range of the optical head 1 at a position where it does not come into contact with the disk medium 2.

Position #b indicates when the optical head l is moved below the reflective surface 3. At this time, it is assumed that the optical head 1 is operating the focus servo similarly to the recording/reproducing state.

Light emitted from a light source (not shown) of the optical head 1 via the objective lens 11 is reflected by the reflective surface 3 and enters the objective lens again, and a change in the amount of light is converted into an electrical signal by the optical reading sensor 12. detected. Further, the output of the optical reading sensor 12 and the output of the reference voltage generator 21 are input to a comparator 22 to obtain a comparison signal output A.

In this embodiment, the output of the reference voltage generator 21 is set to 80% of the output of the optical reading sensor 12 at the time of shipment. The reduction in light intensity due to dirt on the objective lens 11 is -20% or more, which is detected by the output of the comparison signal output being reversed, and this point is determined as the time to clean the dirt on the objective lens 11. There is.

Note that the output of the reference pressure generator 21 is not limited to the above value, and it goes without saying that a part of the disk medium 2 can be used instead of the reflective surface 3.

〔Effect of the invention〕

As explained above, the present invention compares the output signal of the optical reading sensor with the reference signal when the light is emitted from the objective lens of the optical head, reflected by the reflective surface, and then received by the objective lens again. This makes it possible to detect dirt on the objective lens by reducing the amount of light incident on the optical head.
This has the effect of clearly detecting the time to clean the objective lens and preventing the inability to record and reproduce information due to dirt on the objective lens.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention. L: Optical head, 2: Disk medium, 3: Comparator, A: Comparison signal output.

Claims (1)

[Claims] an optical head having an optical reading sensor and an objective lens that emits light from a light source to a disk medium, receives the light from the disk medium, and sends it to the optical reading sensor, and is arranged on the optical axis of the light emitted from the objective lens. An optical information recording and reproducing device characterized in that it comprises a reflective surface and a comparator for comparing the output signal of the optical reading sensor with a reference signal.