JPS6260129A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To secure the correct recording operation even at a low or high temperature by increasing or decreasing the recording power of a laser in accordance with the change of characteristics of a recording medium that is caused by the temperature change. CONSTITUTION:When the recording signal is amplified, the gain of an amplifier is controlled by the temperature and corrected by a share equivalent to the change of the recording characteristics of a magnetic disk due to the temperature of a recording medium. Then a laser is modulated by the recording signal underwent the correction of temperature. Thus a recording current IR is increased or decreased for correction of the difference of sensitivity of the recording medium due to the temperature change. Thus, it is possible to perform the uniform recording to the medium by correcting the change of characteristics due to the temperature and humidity change.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an optical recording/reproducing device that controls the recording power of a laser according to temperature.

2. Description of the Related Art In recent years, optical recording and reproducing devices have improved their recording capacity and speed of retrieval, and because they perform recording and reproducing without contacting the optical recording disk, which is the recording medium, there is no deterioration, and the disk can be used semi-permanently. Because of its ease of use, it is attracting a lot of attention as a means of recording and reproducing video signals and text information.

For example, an apparatus has been put into practical use that uses a laser beam to narrow down the laser beam and irradiate it onto the recording surface of an optical recording disk, thereby changing the recording medium with the heat generated and performing recording.

An example of the above-mentioned conventional optical recording/reproducing device will be described below with reference to the drawings.

FIG. 3 shows a recording block of a conventional optical recording/reproducing device. In FIG. 3, 11 is a recording signal generator, and 12 is a recording signal amplifier that amplifies the recording signal of the recording signal generator 11.

13 is a laser modulation circuit that modulates a laser according to the recording signal amplified by the recording signal amplifier 12 and drives the semiconductor laser 14.

Regarding the optical recording/reproducing device configured as above,
The operation will be explained below.

First, a recording signal to be recorded is amplified by a recording signal amplifier. This amplified signal modulates the laser to control and drive the laser's recording power.

FIG. 2 shows the current output characteristics of a semiconductor laser and its driving method. The recording power of the semiconductor laser is determined by modulating the forward current with the input signal, centering on the recording current IR, to obtain output powers pA and pB.

Generate PC. Recording is performed on an optical recording disk based on this difference in output power.

Problems to be Solved by the Invention However, with the above configuration, there are no problems with regard to changes in recording characteristics due to temperature of the recording medium of an optical recording disk.
Since this is not taken into consideration, there is a problem in that it is not recorded correctly at low or high temperatures.

In view of the above-mentioned problems, the present invention provides an optical recording and reproducing apparatus that is capable of recording correctly even at low or high temperatures, that is, increasing or decreasing the laser recording power by the change in the characteristics of the recording medium due to temperature. This is what we provide.

Means for Solving the Problems In order to solve the above problems, the optical recording and reproducing apparatus of the present invention includes a sensor means for detecting at least one medium that changes the recording sensitivity of an optical recording disk, and a sensor means for detecting at least one medium that changes the recording sensitivity of the optical recording disk. a circuit that outputs a signal proportional or inversely proportional to a change; an adjustment circuit that adjusts the output; a recording signal amplifier that can control the gain of a recording signal by the adjustment circuit; The configuration includes a laser modulation circuit that applies modulation to the laser beam.

Function: With the above-described configuration, the present invention senses the temperature or humidity of a recording medium, such as an optical recording disk, using a sensor means such as a temperature sensor or a humidity sensor, obtains an output proportional or inversely proportional to the detected temperature, and adjusts the output. The circuit controls the gain of the recording signal amplifier and corrects the recording signal by the amount of change in recording characteristics of the recording medium due to temperature or humidity. This ensures accurate recording at all times even if the temperature or humidity changes.

EXAMPLE Hereinafter, an optical recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an optical recording/reproducing apparatus according to an embodiment of the present invention. In Fig. 1, 1 is a temperature sensor;
The temperature of the optical recording disk, that is, the temperature of the recording medium is sensed. 2 is a proportional circuit that outputs a signal proportional to temperature, 3V
i is an adjustment circuit that adjusts its output. 4 is a recording signal generator that generates a recording signal; 5 is a recording signal amplifier that can control the gain of the output signal according to the output from the adjustment circuit 3; and 6 is a generator that responds to the recording signal amplified by the recording signal amplifier 5. This is a laser modulation circuit that modulates the laser and drives the semiconductor laser 7.

Regarding the optical recording/reproducing device configured as above,
The operation will be explained below using FIG. 2.

First, FIG. 2 shows the current output characteristics and driving method of a semiconductor laser. When the recording signal is amplified by the recording signal amplifier 5, its gain is controlled by temperature, and correction is made by the change in recording characteristics due to the temperature of the recording medium of the optical recording disk. The amplified recording signal, which has been corrected for temperature, modulates the laser and controls the recording power of the semiconductor laser. That is, the recording power of the semiconductor laser is adjusted to compensate for differences in the sensitivity of the recording medium due to temperature by increasing or decreasing the recording current IR that drives the semiconductor laser using a recording signal that has undergone temperature correction.

As described above, according to this embodiment, the temperature sensor, the circuit 2 that outputs a signal proportional to the temperature sensor, and the adjustment circuit 3 that adjusts the output are connected to the recording signal amplifier 6 that amplifies the recording signal, and By controlling the gain of the recording signal amplifier 5, correction is made to the recording signal modulated by the laser modulation circuit 6, and the difference in sensitivity due to the temperature of the recording medium of the optical recording disk is corrected on the recording signal side. It can have uniform recording characteristics even at high temperatures.

In the embodiment, the temperature sensor 1 shown in FIG. 1 may be any sensor as long as it senses something that changes the recording sensitivity of the recording medium. A sensor that simultaneously detects humidity may also be used.

Moreover, the proportional circuit 2 may be an inversely proportional circuit that outputs a signal that is inversely proportional to the temperature.

Effects of the Invention As described above, the present invention includes a sensor means, a circuit that outputs a signal that is proportional or inversely proportional to a change in the medium, an adjustment circuit that adjusts the output, and a gain that can be controlled by the adjustment circuit. By providing a recording signal amplifier and a laser modulation circuit, corrections can be made in response to changes in recording characteristics due to changes in the recording medium, such as temperature and humidity.
Recording can be performed uniformly from low to high temperatures or from low to high humidity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing the current output characteristics and driving method of a semiconductor laser of the optical recording/reproducing apparatus, and FIG.
The figure is a block diagram of a conventional optical recording/reproducing device. 1...Temperature sensor, 2...Proportional circuit,
3... Adjustment circuit, 4... Recording signal generator, 5... Recording signal amplifier, 6... Laser modulation circuit, 7...・Semiconductor laser. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] A sensor means for detecting at least one medium that causes a change in the recording sensitivity of an optical recording disk, a circuit that outputs a signal proportional or inversely proportional to the change in the medium, an adjustment circuit that adjusts the output, and the adjustment circuit. a recording signal amplifier whose gain can be controlled by; modulating a laser according to the recording signal amplified by the recording signal amplifier;
An optical recording/reproducing device characterized by comprising a laser modulation circuit that drives a semiconductor laser.