JP3002101U - Rotation state detection device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a rotation state detection device capable of detecting a measurement value indicating the rotation state of a rotating body as an actual state. In a rotation state detecting device for detecting the rotation state of a rotating body (eg, an optical disk) 1 in a non-contact manner, a predetermined light reflection formed by printing on the surface of the rotating body 1 in a radial pattern with respect to a rotation center. A detection means 5 for detecting the patterns 2a and 2b in a non-contact manner, and a signal processing circuit 7 for processing a detection signal of the detection means 5 are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotation state detection device capable of accurately detecting the rotation state of a rotating body. Here, the rotating body is a recording medium such as an optical disk which is an information reproducing apparatus, a magneto-optical disk which is an information recording and reproducing apparatus, or a rotary head drum (cylinder) in a video recording and / or reproducing apparatus.

[0002]

[Prior art]

 Conventionally, information reproducing devices such as compact discs, information recording / reproducing devices such as magneto-optical discs, video tape recorders, record players, etc. rotate at a predetermined rotational speed that is determined in advance. You have to make sure you don't get out of the way. For this reason, there is provided a servo system drive control means for keeping the number of rotations of the disk, which is a rotating body, or the rotary head drum at a predetermined number by a servo mechanism or the like, and making the rotation unevenness within a predetermined value.

The determination as to whether or not the means for responding to the rotation speed and rotation unevenness by the servo mechanism or the like is normally operating has been made as follows. For example, in a compact disc reproducing device or a magneto-optical disc recording / reproducing device, a ring-shaped component obtained by processing a predetermined reflection pattern on the set compact disc or magneto-optical disc is attached to the circumference of the rotating disc, or A part with a light reflection pattern is attached to a part of the disk periphery to detect the number of rotations and uneven rotation, and the servo system is adjusted based on the judgment based on this detection result. I was there. That is, the photodetector placed close to the light reflection pattern detects the light from the light reflection pattern rotating with the disc to detect the rotation speed and the rotation unevenness, and the servo system is adjusted.

[0004]

[Problems to be solved by the device]

 Since the conventional rotation state detection is performed as described above, it is difficult to form the light reflection pattern accurately in a radial pattern with respect to the center of rotation, or a predetermined light reflection pattern is formed on the rotating body. The weight of the rotating body increases due to the mounting of these parts, and the servo system control in a state different from the actual state will be performed, so the actual state of rotation unevenness due to this servo system is not detected. It will be. Furthermore, depending on how the parts are attached, the number of rotations may become unbalanced, and due to variations in the installation accuracy when attaching the parts to the rotating body, measurement errors are likely to occur in the detection result of the rotation state, and in the end, erroneous There was a problem of making adjustments.

The present invention has been made to solve the above-mentioned problems, and as described above, the rotation state is judged by the measured value which is different from the actual value, and the rotation is prevented so as to prevent incorrect adjustment. It is an object of the present invention to provide a rotation state detection device capable of detecting the rotation state of a body by using a measurement value indicating an actual state.

[0006]

[Means for Solving the Problems]

 The rotating state detecting device according to the present invention is a rotating state detecting device for detecting the rotating state of a rotating body in a non-contact manner, wherein a predetermined light formed by printing on the surface of the rotating body in a radial pattern with respect to the center of rotation. The present invention is characterized in that a reflection pattern is provided, and a detection means for detecting the light reflection pattern in a non-contact manner and a signal processing circuit for processing a detection signal of the detection means are provided.

Further, the light reflection pattern is a group of linear light reflection patterns in which a plurality of single linear marks are arranged in the radial direction at regular intervals in the rotation direction. It is a thing.

Further, the rotating body whose rotational state is detected in a non-contact manner is a recording medium such as an optical disk, a readable and rewritable recording medium such as a magneto-optical disk. Further, the rotating body whose rotation state is detected in a non-contact manner is a rotary head drum of a magnetic tape recording and / or reproducing apparatus.

[0009]

[Action]

 The rotation state detecting device according to the present invention emits light to a light reflection pattern printed on a radial surface with respect to the center of rotation of the rotating body, detects the reflected light in a non-contact manner, and detects the number of rotations and uneven rotation of the rotating body. For example, it is possible to accurately detect the rotating state of the rotating body in the actual case. Since there is almost no change in weight and shape due to the light reflection pattern, the rotation speed and rotation unevenness in the actual control state can be detected as described above.

The rotation state detecting device according to the present invention is a single linear light reflection pattern in the radial direction, which is printed on the radial surface with respect to the rotation center of the rotating body and has a constant interval in the rotation direction. To emit light to the light reflection pattern and detect the reflected light to accurately detect the rotating state of the rotating rotating body in the case of the actual control state regarding the number of revolutions of the object and uneven rotation. to enable.

A rotation state detecting device according to the present invention prints a predetermined light reflection pattern on a radial surface with respect to a rotation center of a recording medium such as an optical disk or a magneto-optical disk, and emits light on the printed light reflection pattern. By receiving the reflected light and detecting it in a non-contact manner, it is possible to accurately detect the rotation state of the recording medium such as the optical disc or the magneto-optical disc in the actual servo system control state with respect to the number of rotations and uneven rotation. to enable. Further, a predetermined light reflection pattern is printed on the circumferential surface of the upper surface of the rotary head drum of the magnetic tape recording and / or reproducing apparatus, light is emitted to the printed light reflection pattern, and the reflected light is received and non-reflected. By detecting by contact, it is possible to accurately detect the rotational state in the actual servo system control state regarding the rotational speed and rotational unevenness of the rotary head drum with the magnetic tape loaded and driven.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing the configuration of the rotation state detection device of this embodiment. In the figure, reference numeral 1 is a detection target of the number of rotations and uneven rotation, and in this embodiment is a magneto-optical disk (recording medium). Reference numeral 2a denotes a linear light reflection pattern. The linear light reflection pattern 2a is screen-printed on the periphery of the magneto-optical disk 1 by a conventional printing technique so as to be linear in the radial direction and have a constant interval in the circumferential direction. It consists of various patterns. This linear pattern is printed in a color different from the surface of the magneto-optical disk 1 to be printed so as to be optically distinguishable. Reference numeral 2b is a pattern of a one-rotation display mark indicating that the magneto-optical disk 1 has made one rotation. Reference numeral 3 is a rotary shaft for rotating the magneto-optical disk 1, and 4 is a drive motor for the magneto-optical disk 1. Reference numeral 5 is a reflection type mark detector having a light emitter and a light receiver, 6 is a pattern detection circuit for detecting the linear light reflection pattern 2a, and outputting a signal having a frequency corresponding to the changing cycle of the detected pattern, 7 Is an F-V conversion circuit that generates and outputs a DC voltage according to the input signal frequency.

FIG. 2 is a circuit diagram showing details of the mark detector 5, the pattern detection circuit 6, and the FV conversion circuit 7. In FIG. 2, reference numeral 5a denotes a first linear light reflection pattern 2a for detecting. The mark detector 5b is a second mark detector for detecting the light reflection pattern of the one-turn display mark. 6a is a first pattern detection circuit, and 6b is a second pattern detection circuit.

The first mark detector 5 a includes a reflection type optical sensor 11, a light irradiation amount adjusting resistor 12 on the light emitting side of the reflection type optical sensor 11, and a detection signal level adjusting resistor 13 for adjusting the reflected light amount detection signal level. Is equipped with. The second mark detector 5b includes a reflection type optical sensor 14, a light irradiation amount adjusting resistor 15 on the light emitting side of the reflection type optical sensor 14, and a detection signal level adjusting resistor 16 for adjusting the reflected light amount detection signal level. There is.

The first pattern detection circuit 6 a includes a capacitor 17 that detects the edge of the reflected light amount detection signal, DC level adjustment resistors 18 and 19 that adjust the DC level of the edge detection signal of the reflected light amount detection signal, and a comparator 20. And reference voltage signal generating resistors 21 and 22 applied to the non-inverting input terminal of the comparator 20. The second pattern detection circuit 6b includes a capacitor 23 for detecting the edge of the reflected light amount detection signal, DC level adjustment resistors 24, 25 for adjusting the DC level of the edge detection signal of the reflected light amount detection signal, a comparator 26 and a comparator 26. It is provided with reference voltage signal generating resistors 27 and 28 applied to the non-inverting input terminal.

The FV conversion circuit 7 includes a capacitor 31 that detects the edge of the output signal of the comparator 20, DC level adjusting resistors 32 and 33 that adjust the DC level of the edge detection signal of the reflected light amount detection signal, and F-. A V conversion IC 34 is provided. The relationship between the input signal frequency (indicating the rotation speed of the magneto-optical disk 1) and the output DC voltage of the FV converting IC 34 has a linear characteristic as shown in FIG.

FIG. 4 is a pattern diagram of the linear light reflection pattern 2a and the one-revolution display mark light reflection pattern 2b. In this figure, the linear light reflection pattern 2a and the one-revolution display mark light reflection pattern 2b. Are printed on the surface of the magneto-optical disk 1 so that the lightness and the darkness are reversed. FIG. 5 is an enlarged view of the area R shown in FIG.

Next, the operation will be described. In order to detect the number of rotations of the rotating magneto-optical disk 1, first, the first mark detector 5a and the second mark detector 5b are used to detect the linear shape. The light reflection pattern 2a and the light reflection pattern 2b of the one-turn display mark are optically detected. As a result, pulse signals are output from the first mark detector 5a and the second mark detector 5b, the capacitor 17 causes an edge of the linear light reflection pattern 2a, and the capacitor 23 causes a one-turn display mark. The edge signal of the light reflection pattern 2b is extracted, and the edge signal indicating the edge of the linear light reflection pattern 2a is compared with the reference voltage signal by the comparator 20 to indicate the edge of the light reflection pattern 2b of the one-turn display mark. The edge signal is compared with the reference voltage signal by the comparator 26. In the comparator 26, the edge signal indicating the edge of the light reflection pattern 2b of the one-turn display mark is compared with the reference voltage signal, and the waveform is shaped and output as a pulse signal.

In the comparator 20, the edge signal indicating the edge of the linear light reflection pattern 2 a is compared with the reference voltage signal to perform waveform shaping, and the waveform shaped signal is further extracted by the capacitor 31 to obtain F It is input to the −V conversion IC 34. The F-V conversion IC 34 generates and outputs a DC voltage signal according to the rotation speed of the magneto-optical disk 1 based on the characteristics shown in FIG. In this case, the linear light reflection pattern 2a is accurately printed on the surface of the magneto-optical disk 1 in a radial pattern about the rotation center of the magneto-optical disk 1, and the weight of the linear light reflection pattern 2a is negligible. The influence of the weight of the linear light reflection pattern 2a on the rotation of the servo system drive control of the magneto-optical disk 1 can be almost ignored. That is, the control of the servo system by the weight of the linear light reflection pattern 2a printed on the surface of the magneto-optical disk 1 does not change from the actual state, and the rotation unevenness is almost the actual state. As shown in the figure, the rotation speed and rotation unevenness in the actual state can be detected accurately, so there is no need to make incorrect adjustments.

In the embodiment described above, the linear light reflection pattern or the light reflection pattern of the single rotation display mark is formed by printing on the magneto-optical disk, but the invention is not limited to the magneto-optical disk. Instead, it may be an optical disk or a rotary table of a record player.

Further, a linear light reflection pattern may be formed by printing on a rotating drum of a magnetic tape recording and / or reproducing apparatus. FIG. 6 is a perspective view when a linear light reflection pattern 42a is printed and formed on a rotary head drum 42 which is a rotary body of a magnetic tape recording and / or reproducing apparatus. Here, 43 is a video head and 44 is a magnetic tape.

[0022]

[Effect of device]

 As described above, the present invention has the following effects. (1) A light reflection pattern is printed on the surface of the rotator in a radial pattern with respect to the center of rotation, and the light is reflected by this light reflection pattern and detected by the reflected light in a non-contact manner. Since it is configured to detect the number of rotations and uneven rotation, the addition of the light reflection pattern increases the weight of the rotating body and detects the value of the detected uneven rotation, etc. Therefore, in order to reduce the rotation unevenness, the measured value can be detected with the rotating state of the rotating object being the same as in the actual case, so as to prevent incorrect adjustment processing. . (2) When the rotating body is a recording medium such as an optical disk or magneto-optical disk, the light reflection pattern is directly printed on the cylinder of the optical disk or magneto-optical disk, and the rotating state does not differ from the actual state. Since the measured values such as rotation unevenness can be detected, the parameters of the servo system can be accurately grasped and the correct control system can be corrected. (3) When the rotating body is the rotating head drum of the magnetic tape recording and / or reproducing apparatus, the light reflection pattern is directly printed on the circumference of the upper surface of the rotating head drum, and the rotating state is actually measured. Since it is possible to detect measured values such as rotation unevenness in the same manner as above, it is possible to accurately grasp the parameters of the servo system and correct the correct control system.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a rotation state detecting device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing details of a mark detector, a pattern detection circuit, and an FV conversion circuit of a rotation state detection device according to an embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the input signal frequency of the FV conversion circuit and the DC voltage output.

FIG. 4 is a plan view showing an example of a rotator on which a linear light reflection pattern and a light reflection pattern of a single-point display mark are printed in a rotation state detecting device according to an embodiment of the present invention.

5 is a partially enlarged view of FIG.

FIG. 6 is a perspective view when a linear light reflection pattern is formed by printing on a rotary head drum of a magnetic tape recording and / or reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magneto-optical disk (rotating body) 2a Linear light reflection pattern 2b 1 Light reflection pattern of one rotation display mark 5 Mark detector (detection means) 5a First mark detector 5b Second mark detector 6 Pattern detection circuit 6a 1st pattern detection circuit 6b 2nd pattern detection circuit 7 FV conversion circuit (signal processing circuit) 42 Rotary head drum (rotating body) 42a Linear light reflection pattern

Claims (5)

[Scope of utility model registration request] 1. A rotation state detection device for detecting a rotation state of a rotating body in a non-contact manner, wherein a predetermined light reflection pattern formed by printing on a surface of the rotating body in a radial pattern with respect to a rotation center is provided. Then, the rotation state detecting device is provided with a detecting means for detecting the light reflection pattern in a non-contact manner, and a signal processing circuit for processing a detection signal of the detecting means. 2. The light reflection pattern is a group of linear light reflection patterns formed by arranging a plurality of single linear marks in the radial direction at regular intervals in the rotation direction. The rotation state detecting device according to claim 1. 3. The rotation state detecting device according to claim 1, wherein the rotating body whose rotation state is detected in a non-contact manner is a recording medium such as an optical disk. 4. The rotation state detecting device according to claim 1, wherein the rotating body whose rotation state is detected in a non-contact manner is a readable and rewritable recording medium such as a magneto-optical disk. . 5. The rotating state detecting device according to claim 1, wherein the rotating body whose rotating state is detected in a non-contact manner is a rotating head drum of a magnetic tape recording and / or reproducing apparatus.