JPS586531A - Recorder or reproducer - Google Patents

Abstract

PURPOSE:To lead a head to a suitable position accurately, by shifting the head from a detached position to a closing position with an interval detecting signal obtained from an interval detector and stopping the head based on the proximity detection output obtained from a proximity detection circuit. CONSTITUTION:A disc 1 is loaded on a turn table 3, a head 5 is led on the disc 1 with a radial shifter 15. When a proximity operation switch 29 is turned on and a focus detecting circuit and a proximity detection circuit 31 are operative, then switch elements (a) and (b) of a forward rotation controlling switch circuit 26 are turned on, a motor for a vertical shifter 16 is rotated forward and the head 5 lifts down to the disc 1. A photodetector 10 detects an interval to be narrowed between a condensor lens 8 and the disc 1, a focus control is started, the circuit 26 are turned off with a detection signal of the circuit 31 and the lifting down of the head 5 is stopped.

Description

[Detailed description of the invention]

The present invention provides an improved head displacement method.

['4ji] This relates to a recording or reproducing device. When loading and unloading a disc in an optical disc recording or reproducing apparatus, it is desirable that the optical head be spaced apart from the disc in order to facilitate the loading and unloading of the disc. In order to meet this kind of demand, the public FM354-279
No. 24, No. 5 proposes a method in which the movement of the head is linked to the lid and a position detection switch is provided to bring the optical head closer to the disk during recording and reproduction. However, in this method, the head position is determined by the accuracy of the position detection switch, so the one position detection switch etc. must be arranged with high precision. Furthermore, if the position detection switch is fixedly arranged, it becomes impossible to change the head position depending on the size of the disk. Although we have just described a disk recording or reproducing device that uses an optical head, similar problems arise in devices that use electric or magnetic heads. Therefore, one object of the present invention is to be able to relatively easily and accurately guide a head to a vertically approaching position of a stylized recording medium, and to obtain an appropriate head position regardless of the thickness of the recording medium. The purpose of this invention is to provide a recording or reproducing device that is capable of recording or reproducing information. To achieve the above object, the present invention provides a head for recording or reproducing signals on a serpentine recording medium. A rotating device for rotating the recording medium Y; a feeding mechanism for relatively causing the recording medium to be fed in the radial direction between the recording medium and the head; and 1, for example, the head of the embodiment ( 5) condenser lens (8) and disk (11)
an interval detecting device for detecting an opposing interval between the head or a movable opposing portion located in front of the head and the recording medium, such as an opposing interval between the recording medium; a spacing control device that controls the facing spacing between the head or the opposing portion and the recording medium to an optimum spacing in response to a spacing detection signal sent from the recording medium; a head vertical displacement device for displacing the head to the approach position f; and an approach position detected based on a detection output obtained from the distance detection device indicating that the head has been displaced at the approach position f by the displacement device. a detection circuit, and the displacement device V operates to move the head from the separation position toward the approach position in response to a recording or playback start preparation operation, and the approach position obtained from the approach position detection circuit; The present invention relates to a recording or reproducing apparatus comprising a displacement control circuit that stops the movement of the head by the displacement device based on a detection output. Since the approaching position of the recording medium is detected, the configuration of the device can be simplified and the head can be accurately stopped at the approaching position.Furthermore, since the head is kept at the separated position when loading and unloading the recording medium, the recording It becomes easier to attach and detach the medium, and the head is less likely to be damaged.Also, since the facing distance between the recording medium and the head becomes a predetermined value, a continuous head position V can be obtained regardless of changes in the thickness of the recording medium. Hereinafter, a disk recording device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In FIG. 41, a disk (1
), a disk rotating device consisting of a disk motor (21) and a turn tape # (31) is provided. (5) is an optical head for recording information signals on the disk (II). It consists of a beam generator (6), a beam splitter (7), a condensing lens for focus control (8), a moving coil (9) that drives this lens (8J), and a two-part type for detecting the distance. The beam generation source (6) includes a laser beam and an optical modulator, and generates a recording beam αυ modulated by a signal, and makes the recording beam obliquely incident on the disk (1). Generates focus detection beam a for detecting focus state !1 with reflected light. Beam splitter (7)
The recording beam ttu and the focus detection beam directed toward the disc 1 are passed through. The reflected light a1 of the focus detection beam az is reflected by the photodetector -
The beam is reflected in the direction of , and the outgoing beam and the returning beam are separated in the Y direction. A distance control device consisting of a condensing lens (82) and a moving coil (9) coupled to the condensing lens (82) is
A known voice coil focus control method drives the moving coil (9) and the condensing lens 183 in response to a focus control signal, that is, an interval detection signal, and controls the opposing relationship between the condensing lens (8) and the disk (1). It is a device. 2
The split type detector a consists of a first photodetector element A and a second photodetector element B, and when in just focus, the center of the spot of the reflected light Q3 is on the dividing line between the two elements A and B. A known focus detector is arranged to coincide. The optical head (5) is supported by the base a41 and the feeding mechanism a.
The head (5) is configured to be fed in the radial direction of the disk (11) by the vertical displacement device ae, and is configured to be displaced in the vertical direction of the disk (11) by the vertical displacement device ae. A device for detecting the distance between the lens (87 as an opposing part) and the disk (υ) is the source of the focus detection beam a. A split photodetector aG detects the reflected light Q3 of the beam az.
, an amplifier α'II Nishiki for amplifying the outputs of the 2nd photodetection elements A and B, an error amplification amplifier a and 1 phase for obtaining the error output of the 2nd photodetection signal. Compensation circuit (
), a gain adjustment resistor I2, and a Jl dynamic intensifier circuit (4). Focus detection beam ([3 is disk (
13, so the condenser lens (8)
When the distance between the disk (II) and the disk (II changes), the optical path of the reflected light Q3 changes, and the position of the spot on the photodetector ae changes.If the center of the spot coincides with the dividing line of the photodetector aυ, For example, the output of the first photodetecting element A and the output of the second photodetecting element B become equal, and a signal indicating just focus is output from error amplifier 0.On the other hand, when just focus is not achieved, In this case, a difference occurs between the outputs of the first and #!2 photodetector probes A and B, and a control signal for correcting this is obtained. Moving coil 191 is supplied through 21.
In response to the ft focus control signal, the condenser lens (8) is displaced so as to achieve just focus. The vertical displacement device Qe supported by the base 41041K includes a motor and a vertical feed mechanism and displaces the head (5) between a disk vertically away position and a recordable disk vertically close position; It responds to the output of the displacement control circuit. The displacement control circuit (to) is connected to the motor electric DC power supply (c),
A forward rotation control switch circuit (to) and a reverse rotation control switch circuit (■) are provided between this power supply (to) and the motor of the displacement device α, and a flip-flop (to) that controls the switch circuit (to). include. An approach operation switch 4 is connected to the set input terminal of the flip-flop (to). Therefore, when this switch (to) is turned on, the seventh Q
Two switch elements a and b of the switch circuit (to) at the output
both turn on. The two switch elements a%b of the reversal control switch circuit (2) are turned on by the set output of the flip-flop (30m) in response to the separation operation switch (7), and supply voltage of polarity for reversing the motor. 6υ is an approach position detection circuit, which includes a branch circuit 021 provided in the output line of an amplifier Ql that amplifies the output of the photodetection probe B of $1!2, and an amplifier provided in this branch circuit country. It consists of a detection level adjustment resistor (to) and a Schmitt trigger circuit (7). The Schmitt trigger circuit (to) is an IC-configured circuit that includes an operational amplifier 07) and resistors R8 to R6, and when the input voltage becomes higher than the level of the circuit, it generates a high level output and the input voltage increases. This voltage comparator circuit has hysteresis in the threshold value which generates a low level output when the voltage falls below the jtE20 level which is lower than the first level. The output of this Schmitt trigger circuit (to) is used as the input for the reset terminal of the flip-flop@1, and the focus control start switch (to)
It is also used to control the The mechanism for moving the head (5) by the vertical displacement device (leK) is as shown in No. 2a!0 and 51!3m.
) is connected to the sliding body (to) through the guide member - dovetail groove μQ
By moving along the line, a separated position and an approach position can be obtained. Furthermore, in detail, a member μ2 having a screw hole I is fixed to the sliding body (to), a feed screw link of this screw hole θ11K is screwed, and the screw is connected to the motor through the gear (44) (c). It is rotated by Since the member (6) and the sliding body (to) are non-rotatably engaged with the guide member, when one screw island is rotated nine times in the forward direction by the motor, the sliding body moves forward and the screw When the (goods) rotates in the opposite direction, the space between the sliding bodies moves backward. In addition, as shown in Figure 813 in A')#H40O<[(47
) is arranged L, and by pressing this plate (4η) against the side wall between the sliding bodies with the pressure screw (9), a preload of 5 to withstand circular vibration and external vibration is applied to the sliding body @, and the sliding body (to) is Since it is braked, it is possible to accurately control the position of the head (5).Next, a method of recording a signal on the disc tit using this recording device will be described. Radial feed mechanism O5K before installation
The head (5) is thus moved to the left 11 in FIG. 1 and moved by the vertical displacement device to a vertically spaced position away from the disk (1). Therefore, the diskill
It can be easily attached to the turntable (3). Once the disk 113 has been installed, turn on the power switch. As a result, the disk motor 121 rotates, and the feeding mechanism (151) guides the head 11+ onto the disk.Next, the recording start preparation operation switch (not shown) is operated.
Turn on the approach control switch @t. At the same time, the focus detection circuit and the approach position detection circuit 6υ are made operable. In this recording start preparation state, 1 is the head (5).
but! Since it is located at a position separated in the li direction, the reflected light Ql of the focus detection beam az protrudes from the optical system or enters the second photodetecting element AK'' on one side. The detection output of the reflected light a is not obtained from B. Therefore, the output of the Schmitt trigger circuit is kept at a low level, and the output of the Schmitt trigger circuit is kept at a low level.
is reset by turning on the switch (to), switch elements a and b of the forward rotation control switch circuit (c) are turned on,
The motor of the vertical displacement device aυ rotates in the forward direction, and the head (5) descends toward the disk (II. Head 15
When the temperature is gradually lowered to 1', the distance between the condenser lens (8) and the disk 11) becomes narrower, and the spot of 1 reflected light moves downward from the top of the photodetector a. After passing through the photodetecting element At, it hits the second photodetecting element B and becomes 5. As a result, the input voltage of the Schmitt trigger circuit (to) crosses to the jil level, resulting in a high level output state. This allows the focus servo circuit control start switch (
) is on.9. When focus control is started, the flip-flop (to) is reset and the normal rotation control switch circuit (to) is turned off. Therefore, the vertical displacement motor is stopped. The motor is connected to an electric braking circuit (not shown) for stop control, which causes the motor to suddenly stop and suppress the overshoot of the head (5) to 10 μm or less. When the focus servo starts, the first reflected light Ql is projected near the center of the photodetector αQ, and the output from the detection element B of @2 is always obtained, so the output of the Schmitt trigger circuit (to) is at a high level. is maintained. Furthermore, the Schmitt trigger circuit (to) has hysteresis, so the input signal! Even if it falls below the level [, high level output continues to be generated as long as it is above the second level. After the head (5) has been guided to the approach position, actuation of a recording switch (not shown) starts the projection and radial movement 9 of the recording beam aD. - When recording is finished and the disc (1) is removed. Operate the separation operation switch (to), turn on the reverse control switch circuit with the output of the flip and flop (SOa), and move the head (5) away from the disk (II) by reversing the motor. Since a detection switch (not shown) is provided, the head (5) stops rising when the detection switch is activated.As is clear from the above, the method of this embodiment has the following advantages. 0) By turning on the switch (support), the head (51) automatically moves to the disk vertical approach position and starts recording SV. Therefore, it is possible to start recording extremely easily. (b) When installing and removing the disk tl+, it is separated from the head (51), so it is easy to install and remove it, and there is less risk of damaging the optical head (5). Since this is done by using the second photodetection probe Bi of α, the configuration of the device is simplified. Since the head (5) is lowered to the approach position based on the reference, the optimum head position can be obtained regardless of the thickness of the disk (tl). (e) A focus control start switch (c) is provided, and the Schmitt trigger Since this is turned on by the approaching position detection signal of the circuit circle, there is no operation state that would cause the lens (8) to approach the disk 11) near the end of the descent of the head (5), and the desired approach can be achieved. The head (5) can be stably guided to the desired position. (f) Since the slider (to) in the vertical displacement mechanism of the head (5) is braked by applying pressure by the plate (47) and the press screw, it is possible to stop at the desired approaching position relatively accurately. It is possible. (g) Except for attaching and detaching the disk il+, use the head (5)
Since it is possible to automatically and remotely control the disks 111, etc., it is possible to provide an apparatus that is excellent in terms of workability and safety in consideration of damage to the disk 111 and the like. Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and can be further modified.6 For example, without projecting the focus detection beam α4 obliquely onto the disk +11, input vertically, and its reflected light a3
It is also applicable to a method of detecting the 7-occurrence state by a change in the spot on the detector. In such a method, a plurality of photodetecting elements are arranged concentrically to detect the focus state, and an approach position is detected by the output of one of the photodetecting elements. Further, in place of the Schmitt trigger circuit (G), another level detection circuit may be provided to detect the approaching position. Instead of a flip-flop (inhibit), a switch circuit (inhibit) for an AND gate, etc. may be controlled to turn on/off. Furthermore, the power supply line leading to the motor may be turned off by the output of the Schmitt trigger circuit. It is also applicable to playback devices. Further, the recording start preparation operation and the recording start operation are the same operation, and in response to the operation, a vertical displacement is generated, and when an approaching position is detected by the Schmitt trigger circuit (g). In response to this, recording Y may be automatically started. Alternatively, recording may be started after a certain delay time from the above operation. Alternatively, the start of rotation of the motor (2) may be synchronized with the start of recording.

[Brief explanation of drawings]

#! FIG. 1 is a block diagram of a recording apparatus according to an embodiment of the present invention, FIG. M2 is a sectional view showing the fi [displacement mechanism] of the head, and FIG. 3 is a sectional view taken along the line m--m in FIG. In the symbols used in the drawings, (11 is the disk, (2J is the disk motor, (5) is the optical head, Q (I is the two-split photodetector, (121 is the focus detection beam) , α9 is the feeding mechanism, αe is the vertical displacement device, (
) is a displacement control circuit, C1υ is an approach position detection circuit, and m is a Schmitt trigger circuit. Agent Noriji Takano

Claims (1)

[Claims] +11 A head for recording or reproducing signals on a zigzag recording medium. a rotation device for rotating the recording medium; a feeding mechanism for relatively causing the feeding of the recording medium in the natural direction between the recording medium and the head; the head or a movable opposing part built in the head; and the recording medium. and a distance detection device that detects the facing distance between the two. an interval control device that controls a facing interval between the head or the opposing portion and the recording medium to an optimum interval in response to an interval detection signal obtained from the interval detecting device; a head vertical displacement device for displacing the head between a vertically separated position and a vertically approaching position where recording or reproduction is possible; an approach position detection circuit that detects displacement at a position based on a detection output obtained from the interval detection signal; Driving the displacement device to move the head from the separation position toward the approach position in response to a recording or playback start preparation operation, and based on the approach position detection output obtained from the approach position detection circuit. A recording or reproducing device comprising: a displacement control circuit for stopping movement of the head by the displacement device. (21) The interval detection device is configured to diagonally touch the recording medium by 7t.
- Project a control beam and separate the reflected light of the beam.
Just focus is determined when the spot center of the reflected light and the split armpit of the split photodetector have a certain positional relationship, and the approach position detection circuit A patent that detects the approach position in response to an output of one detection element of the split photodetector that receives the reflected light later when moving from the separation position to the approach position. A recording or reproducing device according to claim 1.