JPS6038741A - Optical information recorder - Google Patents

Abstract

PURPOSE:To attain the accurate control for the position of a writing spot by using a control signal only when the laser output light is not recorded after converting said output light into the record light and non-record light. CONSTITUTION:A position controller controls the position of a writing spot 6 in response to the output characteristics C of a laser 1. The input to be supplied to the position controller is selectively switched. The laser output light B is converted into the record light B1 having high light intensity when a record signal A delivered from a record signal generator is set under a state A1. Then the record element is formed at an information medium 5. This reflected light 7 is made incident to a photodetecting element 9 in an unstable state, and the control signal given from the element 9 is not supplied to the position controller. When a record signal A is set at A2, the light B is turned into the non-record light B2. The reflected light 7 of the light B2 is stable and therefore a stable control signal is obtained and supplied to the position controller. Thus the position of the spot 6 is controlled with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information recording device that optically records information on an information medium such as an optical disk or a magneto-optical disk.

It is relatively easy to detect whether the laser output light is focused on an information medium on which information has already been recorded or whether tracking is being performed properly. In other words, when reproducing SYI information, the laser output light irradiated to the information medium has a low light intensity, and this reflected light is stable (decreased), so it is difficult to check whether the focus is on or not, and whether the tracking is proper. It is possible to detect from the reflected light whether or not the recording is being performed. However, the laser output light during recording is
Since the light intensity is high, if detection is performed using the reflected light including the reflected light during recording, this reflected light is very unstable, so accurate detection cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical information recording device that can easily detect a focus control signal and a tracking control signal to accurately adjust the position of a writing spot.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the laser output light B from the laser 1 is incident light 2 and approaches a semi-transparent mirror 8 such as a half mirror, and an objective lens 4KJ:fi, an information medium in which a concentric or spiral groove 17 is formed in advance. 5 and focuses as a writing spot 6.

Then, the incident light 2 is reflected by the information medium 5 and passes through the objective lens 4 as reflected light 7 to the semi-transparent mirror 3.
The light is focused in only one direction by the cylindrical lens 8 and irradiated onto the light receiving element 9. This light receiving element 9
The light receiving surface is divided into four parts, each light receiving surface 9a, 9b, 9.
c and 9d are connected to the signal processing device 1o that generates control signals for tracking control and focus control.
9) A racking control signal is generated by taking the difference between the sum of the outputs of the light receiving surfaces 9a and 9d and the sum of the outputs of the light receiving surfaces 9b and 9c. and light receiving surface 9
A known method is used to generate a focal point control signal by taking the difference between the sum of the outputs of outputs b and 9a. The output of the signal processing device 10 is inputted to a position adjusting device 12 which adjusts the position of the writing spot 6 by changing the position of the objective lens 4 via a switch 11, which in this embodiment is composed of a transistor or the like. are doing. This switch 11
is a recording signal generating device 1 that generates an information signal to be recorded.
The recording signal A (shown in FIG. 3) output from 8 is connected, and when the recording signal A is AI, it is in a non-conducting state.
When A2 is in the conductive state, input of the control signal to the position adjustment device 12 is selected. Further, as shown in FIG. 8, according to the output characteristic C of the laser 1, the laser 1 outputs laser output light B whose light intensity changes between B1 and B2 in accordance with the recording signal A. That is, the recording signal A is A1
When , the laser output light B is the recording light B1 that forms a recording element such as a high reflectance part or a low reflectance part at the bottom of the groove 17 of the information medium 5, and when the recording signal A is A2, the laser output is Although the light B cannot form the recording element, it becomes the non-recording light B2 whose light intensity is such that the light receiving element 9 outputs a detection value necessary for performing tracking control and focus control. . Therefore, when the laser output light B is the recording light B1, the switch 11 is in a non-conducting state.
At the time of non-recording light B2, the switch 11 is in a conductive state.

Next, to explain the operation, the incident light 2 of the laser output light B passes through the semi-transparent mirror 3, the objective lens 4, and irradiates the information medium 5, and the reflected light 7 passes through the objective lens 4, the semi-transparent mirror 8, and A light receiving element 9 is irradiated through a cylindrical lens 8. At this time, as is well known, if the writing spot 6 of the incident light 2 and the information medium 5 are in the proper position, the reflected light 7 is transmitted to the light receiving surface 9a of the light receiving element 9 by the front linear lens 8. 9b, 9c, and 9d are equally irradiated, resulting in a reflected spot (14). However, if the writing spot 6 shifts in the optical axis direction due to vertical vibration of the information medium 5, the writing spot 6 is The reflected light 7 is distributed like reflective spots 15 and 16, and the writing spot 6 is distributed due to the horizontal deflection of the information medium 5.
When the reflection spot (14, 15, 16) deviates in the direction perpendicular to the optical axis and deviates from the groove 17, the amount of light at the reflective spot (14, 15, 16) changes depending on the direction of this deviation, and this change causes the above-mentioned A control signal is generated in the signal processing device 10 as shown in FIG.

Now, when the recording signal A is in the state A2, the laser output light B is the non-recording light B2, and the drilling operation for forming recording elements in the groove 17 of the information medium 5 is not performed, and the reflected light 7 is is stable, a stable and normal control signal is generated by the signal processing device 10, and since the switch 11 is in a conductive state at this time, the control signal can be input to the position adjustment device [12].

Furthermore, when the recording signal A is in the state A1, the laser output light B
is the recording light B1 and writes the recording element on the information medium 5, so this reflected light 7 becomes unstable and reaches the light receiving element 9.
The amount of light irradiated and the irradiation distribution become unstable, and an unstable control signal is generated. At this time, the switch 11
Since it is in a non-conductive state, it is not input to the position adjustment device 12.

In this way, even if only normal control signals are selected with the switch 11 and are intermittently input to the position adjustment device 12, they are intermittently input at a high frequency, and compared to this high frequency, Since the position adjustment of the writing spot 6 performed by the position adjustment device 12 is performed at a sufficiently low frequency, the position of the writing spot 6 can be adjusted accurately.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and as shown in FIG.
A switch 11 may be provided on the input side of the light receiving element 8, or a switch 11 may be provided on the output side of the light receiving element 9, as shown in FIG.

As described above, the present invention combines laser output light with recording light having a light intensity that allows recording, and non-recording light having an intensity that allows a light receiving element to output a detection value necessary for tracking control and focus control. Since the position of the writing spot is adjusted using a control signal only when the laser output light is non-recording light, it is possible to easily and accurately adjust the position of the writing spot.

[Brief explanation of drawings]

Figure 1 is a diagram showing the principle of an optical information recording device, Figure 2 is a diagram showing the main parts of an embodiment of the present invention, and Figure 8 is a diagram showing the output characteristics of the laser and the relationship between the recording signal supplied to the laser and the laser output light. FIGS. 4 and 5 are diagrams showing essential parts of other embodiments of the present invention. 5... Information medium, 6... Writing spot, 9... Light receiving element, lO... Signal processing device, 12... Position adjustment device,
13: Recording signal generator, A: Recording signal, B: Laser output light, Bl: Recording light, B2: Non-recording light. Patent applicant Mansei Kogyo Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. Modulate the laser output light generated from the laser according to the information signal to be recorded, focus the laser output light on a writing spot to write information on the information medium, and irradiate the light receiving element with the reflected light, Based on the detection value of this light receiving element, control signals for tracking control and focus control (4
], in an optical information recording device that adjusts the position of a writing spot, the recording light has a light intensity that can be recorded according to the recording signal output from the recording signal generator, and is necessary for tracking control and focus control. The laser output light is changed to a non-recording light whose light intensity is high enough to obtain a detected value from the light-receiving element, and the laser output light is irradiated onto an information medium having concentric or spiral grooves, and the laser output light is non-recording light. An optical information recording device characterized in that the position of a writing spot is adjusted using control signals for tracking control and focus control only during light.