DE19655038C2 - Optical storage device - Google Patents

Abstract

An optical storage device for reproducing information from and / or recording information on an optical storage medium by irradiating a light beam on the optical storage medium by a carriage moving in the radial direction of the optical storage medium in a state in which the optical storage medium rotates DOLLAR A characterized in that the optical storage medium comprises: DOLLAR A envelope detection means which, during a search operation of the carriage with respect to the optical storage medium, detects the envelope of a tracking error signal obtained from reflected light of the light beam coming from the optical storage medium, and DOLLAR A is a false lens signal generating means for removing the displacement part of the detected envelope and then outputting a signal having a resultant envelope as a false lens signal equivalent to a lens signal is alent that is used to lock the lens actuator in the center of the carriage, DOLLAR A in which the wrong lens signal is used during a search operation of the carriage for the optical storage medium to lock the lens actuator in the center of the carriage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a optical storage device, or in particular to one optical storage device in which electrical means for the capabilities of sensors that are used in the optical storage device cannot be stowed away if the optical storage device is made thinner.

2. Description of the related art

If spoken of existing storage media are a compact cassette for sound recording, at the magnetic tape is used to record a video cassette draw pictures, and the like known. However are Data recorded on any of these media not freely accessible. Furthermore, the recorded ones Data analog information. Therefore there are such after Share that reproduced data may contain noise nen that the data can be deteriorated if they copied that the data can be deteriorated, if they are stored for a longer period of time, and like.

As for another type of storage medium, is an optical disk for practical use that makes it possible to put a digital signal in which data was converted in a data track record on a disc and use the signal of returned light from a laser beam hitting the Data track was irradiated to read. Examples for the optical disk typical are a compact disk (CD) for recording music, a laser plate (LD) for Recording images, and the like. Further progresses  the development of a digital video disc (DVD) is compactly constructed for recording images. There these types of optical disks, on the other hand, are large capacity, they are included as data storage media the names CD-ROM, LD-ROM and the like have been used.

In recent years there has also been a magneto-opti plate that has been used in practice light, using data on a recording medium of a laser beam and magnetism and the Read data using the laser beam. This one Kind of magneto-optical disk a large storage capacity has acted as an optical storage device in the Form of external storage used for a computer.

As mentioned previously, storage media include Using light an optical disc and a magneto- optical disc. A description is given here under Assumption that the storage media that use light in the are generally regarded as optical disks.

The optical disc that is used for an optical memory The device is used as a storage medium in the spotlight that is in the multimedia systems that are in have emerged in recent years, a key part lung, and is usually stored in a cassette jams to ensure portability. The cassette with optical disk is loaded into an optical disk unit the. Information is then saved using an opti written on the optical disc or by you read.

Currently, the optical disk unit is often used external, via a SCSI interface with a computer connected, used.

The desire has arisen recently, one optical disk unit in a portable personal computer to assemble. Technological development strives with quick steps, a more compact and lightweight  To realize construction. Take one, for example Diskette unit and a hard disk unit, which in the Past as external storage for a personal computer have been used, the trend towards compact construction so much developed that a dis chain unit or a hard disk unit in a gap in a main unit of a personal computer can, which is about 17 mm thick.

To insert the optical disk unit, the means, an optical storage device in the gap with about 17 mm thick for a floppy disk unit or hard disk unit is constructed, the existie optical disk unit can be made thinner.

However, if the optical disk unit is thinner is made so that it is inserted into the approximately 17 mm thick gap can be set for a floppy disk unit or hard plate unit is constructed and on a personal computer is formed, however, because a space within the optical disk unit is vertically limited, a conventional Licher position sensor and a sensor for detecting the Position of an objective lens can be made smaller. Because the size of the position sensor and the sensor for detection The position of an objective lens makes it difficult to get one Carriage on which an optical head is mounted inside position the optical disk unit.

An information record is from USP 5.487.055 nungsgerät known which lens position signals use det. The low-frequency range component of the track sequence error signal is extracted to control the speed tion, and the lens lock is under Using the lens position sensor performed.

From the USP 3,531,222 A there is a zero crossing known signal detection circuit, which for a Use seek control operation of the optical disk device which is the amount of their hysteresis in accordance  with changes in a frequency of the input signal controls. This circuit also uses a lens position onssensor.

SUMMARY OF THE INVENTION

The object of the present invention is to opti cal storage device to provide, even if it is made thinner and dispenses with a position sensor must, an actuator for an objective lens that is on a Trolley is mounted, position it in the middle of the trolley can.

This object is characterized by the features of claim 1 solved.

According to this aspect of the invention, even if the optical disk unit is made thinner and one ago Conventional position sensor must dispense with the position of the Trolley in the laser output setting area for a laser be held on an outer periphery of a diode optical disk medium is defined.

Further advantages and features of the invention emerge from the further claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent from the following Description with reference to the accompanying drawings better understood in which:

Fig. 1A is an oblique view showing a conventional optical disk unit from above;

Fig. 1B is an oblique view showing the conventional optical disk unit from below;

Fig. 1C is a view for explaining an example of the structure of a conventional optical head;

Fig. 2A is an oblique view of the exterior of the front is dung an optical storage apparatus of the present OF INVENTION;

Fig. 2B is an oblique view of the exterior of the back of the optical storage device of the present invention;

Fig. 3 is an exploded oblique view of the front of the optical storage device of the present invention;

Fig. 4 is an exploded oblique view of the back of the optical storage device of the present invention;

Fig. 5 is an explanatory diagram showing the structure of an optical disk;

Fig. 6 is a basic configuration diagram of an optical disk unit;

FIG. 7 is a block circuit diagram showing the configuration of a read LSI circuit in a signal processing unit shown in FIG. 6 in the first embodiment of the present invention;

Fig. 8 is a characteristic graph for explaining the change in the cutting frequency of a filter shown in Fig. 7 according to the present invention;

Figure 9A waves of signals which are obtained in high been imputed average frequency, wherein (1) a shaft of an ID signal showing, (2) a shaft of a primary differential signal shows and (3) a shaft of sectors shows mark signal.

Fig. 9B shows waves of signals obtained with the cut frequency set low, ( 1 ) showing a wave of an ID signal, ( 2 ) showing a wave of a primary differential signal, and ( 3 ) showing a wave of a sector mark signal;

Figures 10A and 10B are flow charts showing a Detekti the position show onssteuerprozedur with respect to a track in the first embodiment of the present invention.

Figure 11 is a timing diagram illustrating the operation described in Figure 10;

Fig. 12 is a schematic view of a main portion of the front of an optical storage device of the second embodiment of the present invention;

Fig. 13 is a schematic view of a main portion of the back of the optical storage device of the second embodiment of the present invention;

. 14A is an enlarged plan view of the top of a lens carriage;

. 14B is an enlarged plan view of the side of the lens carriage;

FIG. 14C is an enlarged plan view of the section through the lens carriage;

FIG. 15A is a diagram showing the relationship between the Laserausgabeeinstellbereich an optical disk Medi killed and the position of the photo sensor for the purpose of Erläu terns of Laserausgabeeinstellbereiches for a laser diode;

Fig. 15B is a waveform diagram showing an output signal of the photo sensor shown in Fig. 15A;

. 16A and 16B are flowcharts Fig describing an example of the current control for a VCM;

Fig. 17 is a flowchart showing an example of the current control for the VCM;

FIG. 18 is a waveform diagram of an respect When the game of the current control for the VCM that executed, when an output of a position sensor is high, and showing a current in said VCM, and a waveform of a photosensor signal;

FIG. 19A is a waveform diagram of a game with respect to In the current control for the VCM that carries out, when the output of the position sensor is low, and shows the current in the VCM and the shaft of Fotosen sorsignals;

FIG. 19B is a waveform diagram of a game with respect to In the current control for the VCM that carries out, when a car collides against an outer stopper, and showing the flow in the VCM and the shaft of the photo sensor signal;

FIG. 20 is an enlarged oblique view of a Linsenbe is tätigers in an optical memory device of the third embodiment of the present invention;

Fig. 21A is a characteristic graph showing a target profile representing the acceleration of the VCM;

Fig. 21B is a characteristic graph showing a target profile representing the speed of the VCM;

Fig. 21C is a characteristic graph showing a target profile representing the position of the VCM;

FIG. 22A is a schematic configuration diagram showing the configuration of an optical storage apparatus of the fourth embodiment of the present invention;

22B shows a schematic configuration diagram showing the configuration of a conventional optical SpeI chervorrichtung.

FIG. 23A is a waveform diagram of a conventional tracking error signal is generated during the search;

FIG. 23B is a waveform diagram of a conventional VCM digkeitscharakteristik the Geschwin shows;

Fig. 23C is a waveform diagram showing a conventional lens position signal;

FIG. 23D is a waveform diagram showing a Spurver folgungsfehlersignal produced according to the present invention during the search;

FIG. 23E is a waveform diagram showing a Linsenpo sitionssignal shows that required by a lens actuator;

Fig. 23F is a waveform diagram showing an incorrect lens signal generated from the tracking error signal shown in Fig. 23D; and

Fig. 23G shows a waveform of a current which flows in the lens actuator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before describing the preferred embodiments, an explanation will be given of the conventional optical disk unit shown in Figs. 1A to 1C.

Fig. 1A is an oblique view showing an optical disk unit, which is a conventional optical storage device from above, in which the optical disk unit is shown without its top cover and circuit board. Fig. 1B is an oblique view showing the conventional optical disk unit from below without its bottom cover. Referring to Fig. 1A and 1B, a base 201 are shown, a carriage 202, a fixed optical unit 203, a lens actuator 204, the magnetic circuits 205, a spindle motor 206, an ejection motor 207, a switch 208, rails 211 and a light emitting diode (LED ) 215 . Main components of an optical disk are mounted on the base 201 . Mounted on the carriage 202 are the lens actuator 204 for moving an objective lens forming a movable optical unit and a mirror (not shown) for changing an optical path, and moves along the rails 211 . The stationary optical unit 203 is composed of a laser diode, a half mirror, a light receiving device and the like, sends a light beam to the movable optical unit and receives reflected light coming from the movable optical unit to reproduce data and servo control information.

Magnetic circuits 205 form voice coil motors for moving carriage 202 along rails 211 . The spindle motor 206 rotates an inserted optical disk medium. The eject motor 207 is incorporated in a mechanism for ejecting the optical disk medium. The switch 208 actuates the ejection motor 207 .

Fig. 1C is a view for explaining an example of the structure of an optical head of a conventional optical disk unit.

On the carriage 202 , as mentioned previously, the lens actuator 204 for moving the objective lens 209 and a mirror 210 for modifying an optical path are mounted, it forms the movable optical unit and moves due to the effects of currents, flowing through coils mounted in holders 214 and magnetic fields formed by the magnetic circuits 205 along the rails 211 .

The stationary optical unit 203 projects a light beam coming from the laser diode 212 onto the mirror 210 to modify the optical path, and thus projects the light beam onto the objective lens 209 . The objective lens 209 is aligned with the optical disc medium 213 due to the operations of the carriage 202 and the lens actuator 204 with a track specified by a higher level unit. The objective lens 209 is focused on the track with which it is aligned, thereby enabling data writing. Furthermore, light reflected from the optical disk medium 213 along a path opposite to the optical path is received by the objective lens 209 and the mirror 210 . Then data and servo control information are reproduced.

As previously mentioned, the objective lens 209 is positioned near a specified track of the optical disk medium 213 by the carriage 202 running along the rails 211 . The optical disk medium 213 and the rails 211 must be strictly parallel to each other to the extent of the parallelism guaranteed by the focus servo control. As shown in FIG. 1B, the LED 215 is attached to the rear of the cart 202 . A position sensor is located in a zone opposite the LED 215 and detects the position of the carriage 202 . A signal sent from the position sensor is used to position the carriage 202 on a specified track of the optical disk medium 213 .

If an optical disk unit is made thinner, however is so that it is inserted into an approximately 17 mm thick gap can be used for a floppy disk unit or hard drives unit is constructed and gebil on a personal computer det, a conventional position sensor or a Sensor for detecting the position of an objective lens stay away because of the space in the optical disk unit is vertically limited. This poses the problem that it will be difficult to position the car.

Below are embodiments of an optical memory device of the present invention. To It begins with the mechanical structure of an optical memory Described device which was made thinner and to which the present invention is applied.  

Figure 2A is an oblique view of the exterior of the front of a thinner 3.5 inch optical disk unit of the present invention. Fig. 2B is an oblique view of the exterior of the back of the optical disk unit shown in Fig. 2A. A front frame 10 has a door 10 b, which is kept closed by a spring, which is not shown. The door 10 b opens when inserting or ejecting a cassette with an optical plate.

The front frame 10 has an eject button 10 a and a hole for manual ejection 10 d. The eject button 10 a is used to instruct ejecting an optical disk cartridge and performing automatic ejection. The manual ejecting hole 10 d is used in the event of a power failure, inspection, or failure to remove an optical disk cartridge to solve a unit by a pin or the like is inserted into this. Furthermore, the front frame 10 has an LED 10 c which lights up to indicate an operating state of the unit.

A drive base 20 on which the front frame 10 is attached is covered with a circuit board 11 with which various IC's and a flexible circuit board are connected, a frame 12 for defining the boundary of the optical disc unit, and a cover 13 . The circuit board 11 is attached to the drive base 20 . The cover 13 is attached by screws 14 a, 14 c, 14 f and 14 h inserted into holes formed in rubber vibration isolators 14 b, 14 d, 14 e and 14 g, as well as in holes in the drive base 20 and the frame 12 are formed. A switch that is gekop pelt with the eject button 10 a is mounted on the circuit board 11 .

The optical disk unit has with the cover 13 and the circuit board 11 , which are placed on the drive base 20 , a height H of about 17 mm. The height h of the front frame 10 with the door 10 d has a relationship of height with respect to the total height H.

Fig. 3 is an exploded view of the optical disk unit shown in Figs. 2A and 2B. Fig. 4 is an exploded view showing the rear side of the optical disk unit of Fig. 3.

. Referring to Figure 3, the optical Plat comprises teneinheit generally seven main parts: a printed circuit board 11, a cassette holder 71 having an opening 71 a, a drive base 20, a lens carriage 30 with a OBJEK tivlinse L, a slide plate 24, a turntable 22 and a cover 13 arranged in this order.

An energy connector and an interface connector are attached to the circuit board 11 . Circuit elements such as a digital signal processor (DSP) for controlling the reproduction, recording and erasing of information relating to an optical disk, an MPU and the like are mounted on one side of the circuit board 11 . The cassette holder 71 is arranged under the circuit board 11 . The circuit board 11 with parts mounted on it is connected to the drive base 20 by screws in a plurality of holes 11 a through a large number of mounting sections 71 of the cassette holder 71 are inserted. Reference numeral 201 denotes a room.

The drive base 20 has openings 20 a to 20 f, which are used to assemble given parts. A stationary optical unit 40 (not shown in FIG. 3) consisting of optical parts for guiding a light beam to a surface of an optical disk or for guiding light reflected from an optical disk to a photodetector gebil det as a united body on the drive base 20 by die casting of aluminum. A cover 40 a is arranged as a dust protection agent on the stationary optical unit 40 .

The lens carriage 30 for holding a lens and for moving it in a radial direction of an optical disk is formed as a united body using a thermally fusible resin or the like, with rinsing in coil sections 32 a and 32 b embedded on both edges of the lens carriage 30 are. A magnet is attached to the back of each of the upper yokes of the lens carriage 30 . Lower yokes of it are used in central openings of the coil sections 32 a and 32 b. In this state, the coil sections 32 a and 32 b are movable with respect to the lower yokes. The ends of the upper and lower yokes are connected by screws, whereby magnetic circuits 33 a and 33 b are realized.

A turntable unit 222 is mounted on a plate 21 . Slide pins 23 a and 23 b are attached to the right and left sides of the plate 21 . The turntable 22 having a diameter of 21 mm extends through the opening 20 a of the drive base 20 toward the cartridge holder 71 out. When an optical disk cartridge is inserted into the cartridge holder 71 , the hub of the optical disk is attracted to and thus held by a magnetic body attached to the front of the turntable 22 . The turntable 22 is connected to a spindle motor for rotating the turntable at a given rotation speed.

An ejection motor 50 , which is used to eject a cassette with an optical disk, is stowed in an ejection motor loading section 55 of the drive base 20 . The ejector motor 50 is connected to the drive base 20 by tightening screws which are not shown and which are inserted through screw holes 50 a and screw holes 55 a.

The slide plate 24 , which slides in a forward and backward direction of the unit when the eject motor 50 is to be ejected, is disposed above the plate 21 with the turntable 22 by the eject motor 50 . If the plate 21 is raised by sliding the slide pins 23 a and 23 b of the plate 21 along the guides 85 of the slide plate 24 , the turntable 22 rises through the opening 20 a. The turntable 22 is then released from the hub of the optical disk, thereby unloading the optical disk cassette.

After the above parts are mounted on the drive base 20 , the frame 12 is attached to the drive base 20 so that the frame 12 can cover the outer periphery of the drive base 20 . The cover, which is formed by pressing a ferromagnetic material, such as. B. stainless steel, is then screwed to the opposite side of the drive base 20 with respect to the cassette holder 71 .

Fig. 5 shows the structure of an optical disk Medi around 1, which is to be inserted into a main body of the optical disk unit through the door 10b of the front frame 10 which has been described in connection with FIG. 2. The optical disc medium 1 is concentrically divided into a plurality of zones from its inner periphery to its outer periphery. In the embodiment, the innermost peripheral part is zone 0 and the outermost peripheral part is zone 9 . Each zone contains a variety of tracks. Each track has an ID division 2 which only reflects a light beam coming from the aforementioned laser diode (also referred to as an embossed division or preformatted division) and an MO recording division 3 which is used to pass data record or reproduce a beam of light (also known as data sharing). The ID division 2 is shown in FIG. 5 with a short black line. When enlarged, the ID division 2 looks like a set of numerous embossed grooves, which are called dimples. A sector mark, a track signal, a section signal, a CRC signal and the like are written in the ID division. A zone number, track number, and the like, indicating a zone, track, and the like, from which data is reproduced smoothly, can be detected by reproducing a signal read from the ID division 2 . The MO record division 3 is an area that lies between ID divisions 2 and is used to record data.

Sections of the optical disk medium 1 having the above structure have substantially the same length. As long as the rotational speed of the optical disk medium 1 is constant, the cycle of ID division in an outermost zone is the fastest.

Fig. 6 is a block configuration diagram showing the basic configuration of the optical disk unit 4 with the aforementioned components. In the optical disk unit 4 , a microprocessor unit (MPU) 42 sends or receives commands or data via an interface 43 to or from a host computer. A read only memory (ROM) 38 in which data is stored on the optical disk medium 1 is connected to the MPU 42 . The rotation of a spindle motor (SPM) 45 for rotating the optical disk medium 1 is controlled by an SPM control unit 36 . Further, an optical pickup 37 for reproducing data can be moved in a radial direction of the optical disk medium 1 by a motor 49 controlled by a coarse motor control unit 48 . The optical pickup 37 irradiates laser light on a data side of the optical disk medium 1 and receives reflected light.

The optical pickup 37 includes a laser diode for irradiating laser light, and, gene a motor which is used to a track of the optical disc medium 1 to verfol. The focus of the laser diode or the tracking is controlled by a Aufnehmersteuereinheit 47th Data reproduced by the optical pickup 37 is processed by a signal processing unit 41 .

The pickup control unit 47 , the SPM control unit 36 and the rough engine control unit 48 are controlled by a plate controller 9 . Signals are sent or received between the disk controller 9 and the signal processing unit 41 . The disk controller 39 sends or receives a command or data to or from the MPU 42 in synchronism with a clock.

Thus, the optical disk unit 4 rotates the optical disk medium 1 at a certain speed using the SPM 45 , moves the optical pickup 37 in the radial direction of the optical disk medium 1 , performs focusing or tracking, and thus reproduces data. In fact, as previously described, the optical pickup 37 includes a stationary optical unit for generating a light beam using a laser diode, and a carriage for projecting the light beam onto a mirror to modify the optical path and thus project the light beam via an objective lens on the optical disk medium 1 . The objective lens on the carriage is aligned with the optical disk unit 1 and focused on the track due to the operation of the lens actuator with a track specified by a higher level unit. Thus, the optical pickup 37 writes data on the optical disk medium 1 . The optical pickup 37 receives light reflected from the optical disc medium 1 via the objective lens and the mirror along a path opposite to the above optical path. The signal processing unit 41 then reproduces data and servo control information. The motor 49 is implemented with voice coil motors for moving the carriage along rails.

The optical disk unit 4 to which the present invention is applied is about 17 mm in thickness. A position sensor and a sensor for detecting the position of an objective lens are not included. The car can therefore not be positioned without taking a suitable measure. If the power supply is switched on, the optical disk unit 4 can not then carry out writing or reading on the optical disk medium 1 if it is uncertain which track of the optical disk medium 1 the optical pickup 37 (carriage) is positioned on.

In an optical storage device according to the first aspect of the present invention, the position of a carriage can be detected using a signal read from the optical disk medium 1 even if it is made thinner and a position sensor and a sensor for detecting the position of an object tiv lens must be dispensed with. The relevant components are described below.

FIG. 7 shows the configuration of a read LSI circuit 160 which is incorporated in the signal processing unit 41 shown in FIG. 6. The read LSI circuit 160 includes two automatic gain control (AGC) circuits 161 and 162 , a multiplexer (MUX) 163 , a filter 164 , a sector mark detection circuit 165 , a logic IC 166 , a synthesizer 167 and a phase locked loop ( PLL) 168 .

The AGC circuit 161 controls the amplification of an ID signal containing a sector mark signal and inputs it to the MUX 163 . The AGC circuit 162 controls the amplification of an MO signal and inputs it to the MUX 163 . The MUX 163 processes a signal sent from an internal ID signal processor or MO signal processor in accordance with an ID / MO switching signal sent from the MPU and sends a resultant signal to the filter 164 . The filter 164 includes an equalizer 641 and two differential circuits 642 and 643 . A signal input to filter 164 is primarily differentiated by differential circuit 642 after it has passed equalizer 641 . A resulting primary differential signal is branched into three sections which are input to the differential circuit 643 , the sector mark detection circuit 165 and the PLL 168 . The primary differential signal input to the differential circuit 643 is further differentiated into a secondary differential signal and then input to the sector mark detection circuit 165 . The sector mark detection circuit 165 detects sector mark pulses in the input primary differential signal and secondary differential signal. The sector mark pulses are sent to the logic IC 166 . An output of the logic IC 166 is input to the synthesizer 167 . A signal sent from the MPU is also input to synthesizer 167 . A synthetic signal provided by synthesizer 167 is then input to a voltage controlled oscillator (VCO) in PLL 168 . The PLL uses the primary differential signal and the signal sent from synthesizer 167 to generate read data and a read clock.

A cut frequency change signal is input from an external MPU to the filter 164 in the read LSI circuit 160 , which has the above components. The filter 164 is a low pass filter in which, as shown in FIG. 8, a normal cutting frequency FC1 and a cutting frequency FC2 used to identify a zone are set. The cutting frequency FC1 is 15.4 MHz, for example, while the cutting frequency FC2 is such a low frequency that it is not normally used for reproducing an MO signal, and is 2 MHz, for example.

FIG. 9A shows signals obtained when the cut frequency set in the filter 164 shown in FIG. 7 is the high frequency FC1, ( 1 ) showing an ID signal, ( 2 ) showing a primary differential signal and ( 3 ) shows a sector mark signal (sector mark pulse). Fig. 9B shows signals that are obtained when the cut-off frequency of the filter 164, the low frequency FC2, wherein (1) an ID signal showing a primary Diffe (2) shows rentialsignal and (3) a sector mark signal (sector mark pulse) shows , In the ID signals shown at ( 1 ) in FIGS. 9A and 9B, a component with a large amplitude is a sector mark signal read by the ID division 2 in FIG. 5. A component with a small amplitude is a signal read from the MO recording division 3 shown in FIG. 5. As can be seen from the comparison between Figs. 9A and 9B, the sector mark signal contains noise and sector mark pulses when the cut frequency is high (FC1). A lot of noise is contained even in the signal read from the MO recording division 3 . In contrast, when the cut frequency is low (FC2), no signal other than sector mark pulses is included in the sector mark signal. Therefore, once the cutting frequency is reduced, a position on the optical disc medium 1 can be predicted by measuring the cycle of the sector mark signal.

In the optical storage device according to the first aspect of the present invention, as mentioned before, the cut frequency of the filter 164 is reduced immediately after the power is turned on. This makes it easier to detect sector mark pulses of a sector mark signal. The cycle of the detected sector pulses is detected, whereby the storage capacity of the optical disk medium 1 , from which data is smoothly reproduced by a carriage and from a track number concerned, is detected.

A procedure of the above detection will be described in connection with the flowcharts of Figs. 10A and 10B.

A routine described in FIGS . 10A and 10B is activated when the optical disk medium 1 is inserted into a main body of the optical disk unit 4 . If the optical disc medium 1 is inserted, the optical disc medium 1 is first driven at step 1,001th At step 1002 , the tracking adjustment is carried out so that a laser beam can be irradiated onto a track of the optical disk medium 1 . At step 1003 , control is given to reduce the cut frequency of filter 164 by changing the cut frequency from the FC1 value to the FC2 value.

After the cut frequency is reduced, a separation of sectors is measured at step 1004 by detecting the cycle of a sector mark signal of an input ID signal. After the sector separation is measured, a sector separation table is consulted at step 1005 . A sector separation table is created in association with a storage capacity of, for example, 128 Mbytes or 230 Mbytes. The table is consulted to see which table contains a value that matches a measured sector separation. Table 1 below is the table stored in the optical disk medium 1 , which has a storage capacity of 128 Mbytes, with zones, standard times, which coincide with a sector, minimum times, which coincide with a sector, and maximum times, with one Sector coincide, are saved.

Table 1

Cycles of zones that represent 128 Mbytes

At step 1006 , it is judged from the table whether or not the optical disk medium 1 can contain 128 Mbytes. If the optical disk medium 1 used may contain, for example, 230 Mbytes, control proceeds to step 1007 . If the optical disk medium is 128 Mbytes, control transfers to step 1017 . The processing of step 1017 to be performed when the optical disk medium 1 is 128 Mbytes is the same as that described below to be performed when the optical disk medium 1 may contain 230 Mbytes. The processing to be executed when the optical Plat may contain tenmedium 1 230 Mbytes, is described as a typical example.

At step 1007 , the cutting frequency is reset to the original value, that is, the cutting frequency is changed from the value FC2 to the value FC1. In this state, a reproduction frequency F, which is assigned to a zone that was derived from a sector separation measurement in step 1004 , is set in step 1008 . At step 1009 , a reproduced signal that is reproduced at frequency F is read. At step 1010 , it is judged whether or not an ID can be recognized at the frequency F. If no ID can be recognized, control transfers to step 1011 . The frequency of raising or lowering the frequency F is calculated. At step 1012 , it is judged whether or not the number of raising or lowering the frequency F is equal to a given number. If the number of raising or lowering the frequency F does not reach the given number, control goes to step 1013 . The frequency F is raised or lowered, and then control returns to step 1009 . The number of raising or lowering the frequency F is determined in accordance with a range from a maximum frequency assigned to each zone in the above table to 2u a minimum frequency assigned to it and a value by which the frequency F is raised or is reduced.

If, at step 1010, an ID cannot be recognized by a given number of raising or lowering the frequency F, it is determined that the storage capacity of the optical disk medium 1 judged at step 1006 is incorrect. Control then passes from step 1012 to step 1017 . The processing to be performed when the storage capacity is 128 Mbytes is carried out.

In contrast, if an ID can be detected by raising or lowering the frequency F at step 1010 , control transfers to step 1014 . A current track position is identified based on the recognized ID information. In this embodiment, the current track position is determined by the identification of step 1014 not finally, but on a trial basis. At step 1015 , the carriage is moved to a control zone of the optical disk medium 1 according to the tentative track. A signal written in the control zone is recognized. At step 1016 , a track on which reproduction is in progress is finally determined.

Fig. 11 is a timing chart showing the above Steue tion, wherein (a) an ID signal showing, (f) a sectors shows pulse signal and displays (g) the operation of the logic IC's 166 of Fig. 7. A rectangular part of (a) is an envelope of an ID signal shown in Fig. 9B ( 1 ) and read from an ID division. (f) shows sector mark pulses of a sector mark signal shown in Fig. 9B ( 3 ). Logic IC 166 drives up a gate signal with the first sector mark pulse of the sector mark signal and keeps the gate signal high while counting down a predetermined count value CV. While the gate signal remains high, logic IC 166 ignores any rising edge of the sector mark signal. Thereafter, the logic IC 166 drives up the gate signal with the first pulse after an undefined period U of the sector mark signal ends, and holds the gate signal at the high level while counting down a predetermined count.

A control program to be executed by the logic IC 166 measures the cycle of sector mark pulses by measuring the interval between rising edges of the gate signal, and then determines a zone number from a zone of the optical disc medium 1 in which the reproduction in Is underway.

Next, an optical storage device of the described second embodiment of the present invention ben.

Fig. 12 is a schematic view of the main portion of the front of the optical disk unit described in connection with Figs. 2A to 4, in which the circuit board 11 , the frame 12 and the cover 13 are removed. FIG. 13 is a schematic view of the main portion of the back of the optical disk unit shown in FIG. 12.

A lens actuator 60 with an objective lens L and magnetic circuits for driving the lens are mounted on the lens carriage 30 . A flexible printed circuit board 39 a for inputting signals containing a signal that is used to drive the lens actuator 60 in a focus direction or tracking direction is attached along the coil section 32 a of the lens carriage 30 using an adhesive. Furthermore, a carriage cover 115 made of a ferromagnetic material, such as. B. rust free steel, arranged so that it can surround the objective lens L. Voice coil motors (VCM) are arranged on both edges of the lens carriage 30 for moving the lens carriage 30 in the radial direction of an optical disk. The VCM's include the coil sections 32 a and 32 b of the lens carriage 30 and the magnetic circuits 33 a and 33 b, which each contain yokes and magnets.

Guide rails 113 a and 113 b to facilitate the movement of loading the lens carriage 30 are attached, being held under pressure by leaf springs 112 a, 112 b and 114 . In other words, the leaf springs 112 a and 112 b act as attachment sides for attaching the guide rail 113 b by urging the guide rail 113 to abut against the walls of the drive base 20 which are opposite to both ends of the guide rail 113 b. The Blattfe the 114 presses the guide rail 113 a to the guide rail 113 b. The guide rails 113 a and 113 b are in engagement with bearings 31 a to 31 c, which are arranged at the limits of the coil sections of the lens carriage 30 .

Incidentally, the state of the lens carriage 30 shown in FIGS. 12 and 13 is a locked state. This can be seen from the fact that a carriage lock 26 abuts the lens carriage 30 . The carriage lock 26 prevents the lens carriage 30 from leaving an initial position in the radial direction of an optical disk.

A projection 22 a is arranged in the middle of the turntable unit 222 , which protrudes through the opening 20 a of the drive base 20 , and is inserted into a central hole in the hub of an optical disk. A flexible circuit board (FPC) 89 is attached to the plate 21 using an adhesive. A sensor 86 for detecting a write enable set on an optical disk cartridge, a sensor 87 for detecting write protection set on an optical disk cartridge, and a cartridge insertion sensor 88 for detecting the insertion of an optical disk cartridge mounted on the FPC 89 .

Incidentally, a cassette with a magneto-optical disc of 3.5 inches with a storage capacity of 128 MByte complies with the ISO / IEC standard 10090, while the one with a storage capacity of 230 MByte complies with the ISO / IEC standard 13963. These types of disk cartridges are already on the market. A cassette with an optical disc is therefore not shown in particular. Furthermore, one end of the FPC 89 is connected to a connector mounted on the FPC 39 for sending a signal that is used to control the movements of the lens carriage 30 and lens actuator 60 . The FPC 39 is laid along a cross side of the drive base 20 and bent to be connected to a connector which is arranged on a circuit board.

A slide plate 24 is arranged under the plate 21 , that is, between the drive base 20 and the plate 21 . If the slide plate 24 moves in a forward and backward movement Y of the unit, the relative positions of dowel pins 29 a to 29 c, which are arranged on the drive base 20 , change with respect to a plurality of grooves 24 a to 24 c, which are formed on the slide plate 24 . The slide plate 24 moves backward in an ejecting instruction, thereby detaching an optical disc cartridge from the optical disc unit. Thereafter, the sliding plate 24 by the elastic force exerted by coil springs 28 a and 28 b, of which one end is connected to the sliding plate 24 and of which the other ends are connected to the mounting pins 29 a and 29 b, moved forward in the optical disk unit and thus quickly returned to the starting position.

The ejection instruction can be issued by depressing an ejection button 10 a, which is arranged on a front frame 10 , or by vigorously inserting a pin or the like into a hole for manual ejection 10 d. In the former case, if the eject button 10 a is never pressed, an ejection motor 50 is driven. When an edge 24 d of the slide plate 24 is pulled, the slide plate 24 moves backward in the optical disk unit. If in the latter case a pin or the like is vigorously inserted into the hole for manual ejection 10 d, the pin abuts against a right wall 10 f of the slide plate 24 . This causes the slide plate 24 to move rearward in the optical disc unit.

A leaf spring 111 is attached to a stationary optical unit 40 which is attached to the rear of the Antriebsba sis 20 . The leaf spring 111 presses an M lens 46 and an S lens 47 against surrounding walls of the Antriebsba sis 20 and so fastens them. A photodetector 52 and a photodetector 53 are stowed in charging sections of the drive base 20 . The photodetector 52 detects a reproduced data signal sent from an optical disc using returned light which is passed through the lens carriage 30 , which serves as a movable optical unit. The photodetector 53 detects a focus servo control signal and tracking servo control signal.

Reference numerals 23 a and 23 b denote slide pins of the plate 21 . 91 denotes an FPC. 91 c and 91 d denote screw holes. 92 denotes a connector.

FIG. 14A is an enlarged plan view showing senwagen the Lin 30 from above. FIG. 14B is an enlarged side view. Fig. 14C is an enlarged sectional view. Referring to FIGS. 14A to 14C bearings 31 a to 31 c, coil sections 32 a and 32 b, a FPC 39 a, a Actuate the gerbasis 61, screw fasteners 61a and 61b, yokes 61 c, 61 d and 63, a Focus coil 65 , tracking coils 66 a and 66 b, wires 67 a and 68 a, connecting plates 67 b, 67 c, 67 d and 69 d, reference trenches 121 a to 121 c, a coil spring 122 a, a screw 122 b, a condenser lens 129 , for receiving or irradiating a light beam from or onto the stationary optical unit 40 , a driver 152 , a lens holder 621 , a wire holder 622 and an objective lens L are shown. An arrow A shows a preload.

In the lens carriage 30, which has the above components, in this embodiment, an intercepting projection 35, the processing in a direction parallel to a direction of movement of the carriage 30 is extended, disposed on an edge of the carriage 30, which is one of a spindle motor for rotating optical disk medium is removed. The intercepting jump 35 is shown in FIGS . 12 and 13.

Furthermore, in this embodiment, a photosensor 7 , which comprises a light-emitting device 5 and a light-sensing device 6 , is arranged transversely over a movement path which the intercepting projection 35 tracks with the movement of the carriage 30 . The photosensor 7 is disposed at a position where light incident on the photosensor 7 is intercepted by the intercepting protrusion 35 only during a period during which the carriage 30 is located in a laser output setting area which is near the outside Scope of the optical disk medium 1 is defined. Therefore, in the optical disk unit according to the second aspect, it is detected whether or not light that is incident on the photo sensor 7 is intercepted by the intercepting projection 35 . Thus, it is detected whether or not the carriage 30 has moved to the laser output setting area defined on the optical disk medium 1 . The laser output setting area is used to set the laser output or the intensity of a laser beam to be irradiated on the optical disc medium 1 , and is normally defined on the outer periphery of the optical disc medium 1 so that data zones of the optical disc medium 1 are not adversely affected.

An amount of light of a laser beam coming from the stationary optical unit 40 in the optical disk unit is set to a certain level. If the amount of light does not reach the level, the optical disk unit will not work. Therefore, it is necessary that the optical disk unit detect an amount of light from a laser beam when the power supply is turned on. If a laser beam is checked in a data zone of the optical disc medium 1 to detect the amount of light of the laser beam, data erasure must be feared. Detection of an amount of light of a laser beam is therefore carried out when the carriage 30 is located in the laser output setting area defined on the outermost periphery of the optical disk medium 1 . The carriage 30, therefore, must be displaced to be in the Laserausgabeeinstellbereich defined on the outer most circumference of the optical disc medium 1 immediately after the power supply of the optical discs is switched medium. 1

FIG. 15A and 15B are diagrams for explaining the La serausgabeeinstellbereichs for a laser diode. FIG. 15A shows the relationship between the Laserausgabeeinstellbereich on an optical disk medium and the position of a photo sensor. FIG. 15B shows an output signal of Fotosen sors.

Referring to Fig. 15A, an optical disk medium 1 is shown. The left side of the drawing is an outer peripheral side, while the right side of it is an inner peripheral side. A given area on the outermost circumference side of the optical disc medium 1, to the output of a laser diode whose light is irradiated by the carriage 30 on the optical disc medium 1 set a Laserausgabeeinstellbereich 1 A, is used. Within the laser output setting area 1 A there is a data zone 1 B which contains a large number of tracks. The carriage 30 is guided by rails, which are not shown and which run along both edges of the carriage 30 , and driven by the VCM 15 to move in the radial direction of the optical disk medium 1 . An outer stopper 15 A is arranged on the side of the outermost circumference of a range of movement of the carriage 30 , and an inner stopper 15 B is arranged on the side of its inner most circumference.

As described above, in the photosensor 7 placed in a main body of the optical disk unit, its incident light or incident light is intercepted by the intercepting protrusion 35 formed on the carriage 30 when the carriage 30 is in the laser output setting area 1 A is arranged for a laser diode, which is defined on the optical disk medium 1 . An output of the photo sensor 7 is input to the MPU 42 . Based on the output of the photo sensor 7 , the MPU 42 causes a current to flow into the VCM 15 through the VCM driver 8 , and thus moves the carriage 30 in the radial direction of the optical disk medium 1 .

FIG. 15B shows a waveform of an output signal of the photo sensor 7. The output of the photo sensor 7 is high when the incident light of the light receiving device will be intercepted by the intercepting projection 35 when the carriage 30 is disposed in the Laserausgabeeinstellbereich 1 A for the laser diode.

Next, in connection with the flowcharts of FIGS. 16A and 16B, a procedure for positioning the carriage 30 in the Laserausgabeeinstellbereich 1 A for the laser diode for the purpose of adjusting the output of the laser diode or the intensity of laser light, the optical from the sta tionary Unit comes after the power is applied to the optical disk unit implemented in the optical disk unit that includes the carriage 30 that has the above components but has no position sensor.

At step 1601 , it is judged whether a position sensor is on or not. In this control procedure, the position sensor designates the photo sensor 7 . The state in which the position sensor 7 is on is a state in which the incident light of the photosensor 7 is intercepted by the intercepting protrusion 35 formed on the carriage 30 . First of all, judging whether the position sensor 7 is turned on or not is aimed at judging at which position on the optical disk medium 1 the carriage 30 is located. If the position sensor is a 7, the carriage 30 has been placed already setting range to a position within the Laserausgabeein 1 A for the laser diode. If the position sensor 7 is off, the carriage is arranged in any other area except the area Laserausgabeeinstell 1 A for the laser diode on the optical Plattenme dium 1 thirtieth A procedure for positioning the carriage 30 in the Laserausgabeeinstellbereich 1 A for the laser diode, depending on whether the carriage 30 is located in the laser output setting range for the laser diode or not, when the power supply of the optical disk unit is turned on will be described below.

(1) When the carriage 30 is placed in the laser output setting area for the laser diode

In this case, it is found at step 1601 that the position sensor 7 is on. Control therefore passes to step 1602 . A current I is applied to the VCM 15 by the VCM driver 8 to move the carriage 30 to the inner periphery side of the optical disk medium 1 . With the application of the current I, the carriage 30 moves toward the inner periphery of the optical disc medium 1 . In step 1603, it is judged whether the position sensor 7 is off or not, i.e., whether the carriage 30 the Laserausgabeeinstellbereich 1 A for the Laserdi ode has left. If the position sensor 7 is off, control transfers to step 1605 . If the position sensor 7 is not turned off, control transfers to step 1604 . At step 1604 , the current I is increased. Control then returns to step 1603 . At step 1603 , it is again judged whether the position sensor 7 is switched off or not.

At step 1605 , to which control passes when it is found at step 1603 that the position sensor 7 is turned off, a current i is applied to the VCM 15 by means of the VCM driver 8 to drive the carriage 30 to the outer periphery of the optical disc medium 1 to i bewe gene. the polarity of the current is opposite to that of the current I. With the application of the current i, the carriage 30 moves toward the outer periphery of the optical disk medium 1 . In step 1606, it is judged whether the posi tion sensor is switched 7 or not, that is, whether the carriage 30 has entered into the Laserausgabeeinstellbereich 1 A for the laser diode. If the position sensor 7 is off, control transfers to step 1607 . The current i is increased. At step 1606 , it is again judged whether the position sensor 7 is turned on or not.

If it is found at step 1606 that the position sensor 7 is turned on, control transfers to step 1608 . The value of current i at that time is reserved as interrupt current Aout. At step 1609 , a current I is applied to the VCM 15 by the VCM driver 8 to move the carriage back to the inner periphery of the optical disk medium 1 . The application of the current I causes the carriage 30 to move toward the inner periphery of the optical disk medium 1 again . At step 1610 , it is judged whether the position sensor 7 is turned off again or not. If it is found at step 1610 that the position sensor 7 is not turned off, control transfers to step 1611 . Current I is increased and control returns to step 1610 . At step 1610 , it is again judged whether the position sensor 7 is turned off or not.

If it is found at step 1610 that the position sensor 7 is turned off, control transfers to step 1612 . The value of the current I at that time is reserved as the uninterrupted current Ain.

As mentioned above, when the power supply of the optical disc medium 1 is turned on, if the car is 30 in the Laserausgabeeinstellbereich 1 A for the laser diode, the carriage 30 temporarily evacuated from the area. The value of the current i that flows when the carriage 30 re-enters the area is stored as the interruption current Aout. The value of the current I which flows when the carriage 30 comes out of the area immediately after entering the area is stored as the non-interrupt current Ain.

(2) When the carriage 30 is located outside the laser output setting range for the laser diode

In this case, it is found at step 1601 that the position sensor 7 is off. Control transfers to step 1613 . A current i is applied to the VCM 15 by the VCM driver 8 to move the carriage 30 to the outer periphery of the optical disk medium 1 . The application of the current i causes the carriage 30 to move toward the outer periphery of the optical disk medium 1 . In step 1614, it is judged whether the position sensor 7 is turned on or not, that is, whether the carriage is in the Laserausgabeeinstellbereich 1 A for the laser diode eingetre th 30th At step 1615 , current i is increased and control returns to step 1614 . At step 1614 , it is again judged whether the position sensor 7 is switched on or not.

If it is found at step 1614 that the position sensor 7 is on, control transfers to step 1616 . A current I is applied to the VCM 15 by the VCM driver 8 to move the carriage 30 to the inner periphery of the optical disk medium 1 . The polarity of the current I is opposite to that of the current i. The application of the current I causes the carriage 30 to move toward the inner periphery of the optical disc medium 1 . At step 1617 it is judged whether the position sensor 7 is off or not, i.e., whether the carriage 30 come out of the Laserausgabeeinstellbereich 1 A for the laser diode. If the position sensor 7 is on, control transfers to step 1618 . The current I is increased. At step 1617 , it is judged whether the position sensor 7 is turned off or not.

If it is found at step 1617 that the position sensor 7 is turned off, control transfers to step 1619 . The value of current I at that time is reserved as interrupt current Ain. At step 1620 , the current i is applied to the VCM 15 by the VCM driver 8 to move the carriage to the outer periphery of the optical disk medium 1 . The application of the current i causes the carriage 30 to move toward the outer periphery of the optical disk medium 1 . At step 1621 , it is judged whether the position sensor 7 is turned on again or not. If the position sensor 7 is not turned on, control transfers to step 1622 . The current i is increased. At step 1621 , it is judged whether the position sensor 7 is turned on or not.

If it is found at step 1621 that the position sensor 7 is turned on, control transfers to step 1623 . The value of current i at that time is reserved as non-interrupt current Aout.

As mentioned above, when the power supply of the optical disc medium 1 is turned on, if the car is 30 outside the Laserausgabeeinstellbereiches 1 A for the laser diode, the carriage 30 temporarily moves gabeeinstellbereich 1 A for the laser diode in the laser equipment. The value of the current I that flows when the carriage 30 comes out of the area is stored as an interruption current Ain. The value of the current i that flows when the carriage 30 enters the area immediately after it comes out of the area is stored as the non-interrupting current Aout.

Thus, after measuring the interrupt current Ain and the non-interrupt current Aout that flow when the carriage 30 is within the laser output setting range for the laser diode and those that flow when the carriage 30 is outside of it, control transfers to step 1624 , Average values of the interruption currents Ain and non-interruption currents Aout are calculated as the holding current values Ahld. At step 1625 , the holding current values Ahld are set in the VCM driver 8 . Using the holding current values Ahld, the carriage 30 can be locked while it is offset to lie in the laser output setting range for the laser diode.

The reason that the values of currents flowing when the carriage 30 moves back and forth are measured and averaged is because a current can be roughly changed in steps and an operation time can be shortened eventually. Another reason is that a current to be changed differs depending on the direction in which the carriage 30 is moved.

The processing described in connection with Figs. 16A and 16B is carried out when the optical disk unit is placed horizontally. On the contrary, if the optical disk unit is tilted, for example, if the optical disk unit is tilted toward the outer periphery of an optical disk medium, if the carriage 30 is arranged on the inner periphery of the optical disk medium, the above processing poses problems. According to the above processing, even if the optical disk unit were inclined, a current would be set that is used to move the carriage 30 toward the outer periphery of an optical disk medium, assuming that the optical disk unit is arranged horizontally , Since the tilt of the optical disk I would act on the integrated current, the carriage 30 could be the optical disc medium are accelerated toward the outer periphery, and discharged 15 A against an external stopper.

In this case, the carriage 30 collides of the pulses resulting from the collision of 15 A with the outer stopper, back to the inner circumference of the optical disc medium due. As a result, the position sensor 7 is turned on and off for a short period of time. This can make it impossible to precisely set a holding current Ahld. In this case, since a precise holding current Ahld cannot be obtained, the carriage 30 cannot be stopped. The carriage 30 holds, while it abuts against the outer stopper 15 A.

To overcome the above problem, a process is added: a difference Adif between the measured break current Ain and non-break current Aout is calculated; and when the difference Adif becomes equal to or less than a certain value, the interruption current Ain and non-interruption current Aout are measured again. This example of control is described using the flowchart of FIG. 17. The processing from step 1601 to step 1623 is identical to the process described in connection with FIGS. 16A and 16B. The description of the processing is omitted.

When step 1612 or 1623 of the processing described in FIGS. 16A and 16B is completed, control proceeds to step 1702 of the processing in FIG. 17. At step 1702 , the difference Adif (absolute value) between the measured interrupt current Ain and the non-interrupt current Aout is measured. At step 1702 , it is judged whether or not the difference Adif is equal to or larger than a given reference value As1. If the As1 value is greater than the Adif value, control returns to step 1601 . The processing from steps 1601 to 1623 is repeated. Conversely, if it is found at step 1702 that the As1 value is equal to or less than the Adif value, control transfers to step 1624 . An average of the interruption current Ain and the non-interruption current Aout is calculated as the holding current Ahld. At step 1625 , the value of the holding current Ahld in the VCM driver 8 is set. With the holding current Ahld, the carriage 30 can be locked while it is offset to lie in the laser output setting area for the laser diode.

The reason that the above processing is carried out is that when the optical disk unit is tilted toward the outer periphery of an optical disk medium since the carriage 30 turns the position sensor 7 on and off for a short period of time, a difference between measured currents becomes smaller than a difference between normally measured currents. Incidentally, since the carriage 30 is arranged at a position where the position sensor 7 is on, the second measurement can be carried out without any problem.

Fig. 18 shows an example of the current control for the VCM described in connection with Figs. 16A and 16B, in which when the power of the optical disk unit is turned on, the output of the position sensor 7 is high. In Fig. 18, a current to be applied to the VCM and the output of the photosensor 7 are recorded with respect to time. In FIG. 18, the time interval (a) coincides with step 1601 to step 1604 , the time (b) coincides with step 1605 , the time interval (c) coincides with step 1606 to 1607 , the time (d) coincides with step 1608 , the time interval (e) coincides with step 1609 to step 1611 and the time (f) coincides with step 1612 .

Fig. 19A shows an example of the current control for the VCM described in connection with Figs. 16A and 16B, in which when the power of the optical disk unit is turned on, the output of the position sensor 7 is low. In Fig. 19A, a current to be applied to the VCM and the output of the photosensor 7 are recorded with respect to time. The time (b) 'coincides with step 1616 , the time interval (c)' coincides with step 1617 to 1618 , the time (d) 'coincides with step 1619 , the time interval (e)' coincides with step 1620 to step 1622 , and the time (f) 'coincides with step 1623 .

Fig. 19B shows an example of the current control for the VCM described in connection with Fig. 17, in which when the power of the optical storage device is turned on, the output of the position sensor 7 is low. In this case, the output of the photo sensor 7 is driven up at the time (b) ". However, since the carriage 30 collides with the outer stopper 15 A and rebounds, the output signal of the photo sensor 7 at the time (d)" is reversed. In this case, the processing described in FIG. 19A can be carried out after the time (f) ".

Next, an optical storage device of the described third embodiment of the present invention ben. In front of the optical storage device, a conventional Licher lens actuator briefly described.

A carriage is placed in an optical disk unit which an objective lens is mounted through a VCM in radial direction of an optical disk medium moves. On Tracking actuator for fine adjustment of the object tiv lens inside the car is locked with the VCM, whereby each track is accessed (search). The conventional Liche car therefore contains a position sensor for detection the position of the car and a lens position sensor for detecting the position of the objective lens on the Dare.

An optical storage device of the present invention However, the invention is without a position sensor and lens position sensor because the optical storage device is made thinner is.

Fig. 20 is an enlarged view of a Linsenbetä tigers 62 mounted on a cart. A movable part of the actuator 62 comprises a lens holder 621 , a focus coil 65 and tracking coils 66 a and 66 b. The lens holder 621 is made of a thermosetting resin or the like, so that an objective lens L can be kept movable in a tracking direction or focus direction. The focus coil 65 is attached to a wall of a central opening of the lens holder 621 using an adhesive. The tracking coils 66 a and 66 b are attached using an adhesive on an upper surface opposite the wall to which the focusing coil 65 is attached.

Furthermore, the two tracking coils 66 a and 66 b, which are adjacent to the left and right portions from one side of the focus coil 65 , are wound in a direction that is substantially perpendicular to the plane of the winding of the focus coil 65 . One end of each of the Spurverfolgungsspu len 66 a and 66 b protrude from the edge of the yoke 63 out, whereby a magnetic circuit is formed on the right and left sides of the yoke. In other words, parts of the tracking coils 66 a and 66 b, of which magnetic fluxes expand vertically, are arranged outside the magnetic circuit so that the tracking coils are not affected by another magnetic flux. Control is thus carried out so as not to cause mechanical vibrations.

The magnetic circuit of the actuator 60 includes a magnet 64 , a yoke 61 c, a yoke 61 d (see FIG. 14C) and a cover yoke 63 . The magnet 64 is arranged on an actuator base 61 so that the magnet 64 of the focus coil 65 is located in the central opening of the lens holder 621 , which forms the movable part of the actuator 62 . The yoke 61 c includes the bent part of the actuator base 61 for receiving a magnetic force from the magnet 64 . The curved part of the yoke 61 d, which is not shown, is opposite the yoke 61 c. The cover yoke 63 is shaped like a letter U to connect the yokes 61 c and 61 d.

The lens actuator 62 further comprises four wires 67 a, 68 a, 69 a and another (one wire is not shown), four attenuators 67 b, 68 b, 69 b and another (one link is not shown), and four connecting plates 67 d, 68 d, 69 d, and another (the one plate is not shown). The four wires 67 a, 68 a, 69 a and another (a wire is not shown) hold the movable part of the actuator 62 . The four connection plates 67 c, 68 c, 69 c and another (a plate is not shown) are connected using an adhesive, their holes are engaged with projections 62 a and 62 b of the lens holder, and hold the ends of the wires on the side of the objective lens. The four terminal plates 67 d, 68 d, 69 d and the other a plate (not shown) are connected to a wire holder which is fes using a Haftstof with an edge of the actuator base 61 engaged. The four attenuators 67 b, 68 b, 69 b and another (one member is not shown) are used to absorb the vibrations of the wires.

One end of an FPC 39 c extends to the wire holder 622 and is soldered to the four connection plates on the wire holder 622 . The four connection plates on the lens holder 621 are soldered to the two lines of each of the focus coil 65 and the tracking coils 66 a and 66 b. The focus coil 65 , the tracking coils 66 a and 66 b and the FPC 39 a are thus connected. Electrical connections are thus achieved without it being necessary to lead thin lines of the coils to the outside. Therefore no interruption is feared. Reliability can thus be improved.

Furthermore, the four wires and the terminal plates, which are arranged on both edges of the wires, are produced by pressure on a leaf spring material or linear spring material using a pair of compression molds (U-shaped), defining a state in which two right and left wires are connected. The two right and left wires are then assembled into the wire holder 622 , being connected together (in the U shape). Then the connection is cut out. The use of the wire assembly thus produced simplifies the handling or handling of small parts and improves the assembly efficiency.

The actuator base 61 is bolted to the lens carriage 30 by mounting sections 61 a and 61 b formed in the bent fragments of the actuator base 61 , with all parts mounted on the actuator 62 .

In the lens actuator 62 having the above components, a VCM plays a key role in moving the objective lens L during rough control or search control. Search control depends on approaching a speed at which fine control moves the objective lens to the closest possible value of 0. In order to control the search speed so that the final speed becomes 0, it is necessary to measure the search speed precisely. The search speed can be measured using a zero-crossing pulse generated when the objective lens L crosses a track. A higher speed can be calculated using the number of pulses sampled during a unit of time. A lower speed can be calculated using a pulse spacing. A signal used to measure speed is a tracking error signal in both cases.

The objective lens L is made by a system whose free is 2, that is, by tracking actuator, moved on a VCM trolley. It can't be gene rell said that "the tracking error signal represents a value that is a function of the position of a VCM is equal. "The tracking error signal contains always a component that the position of a lens inside half of the car indicates (that is, an edition of a Lin senpositionssensors). If the car accelerates very much becomes high during search or the like Speed is prophesied that the Lens due to inertia on the carriage very ver pushes. The tracking error signal therefore poses represents a value that is a function of the combination of the Position of the VCM and the output of the lens position sensor is equal to.  

If the lens position sensor is used, can a lock control of the lens on the cart, a so-called "lens lock servo control", under Ver application of an output signal of the lens position sensor be carried out. In this case it applies that "the tracking error signal represents a value, de 13484 00070 552 001000280000000200012000285911337300040 0002019655038 00004 13365r of a function the position of the VCM is the same. "

In an optical storage device which has neither a position sensor nor a lens position sensor, a lens is locked on a carriage according to the following method (1) or (2):

• 1. The lens will accelerate as that of the car accelerated, causing the appearance of a relative shift is prevented; or
• 2. The carriage is moved so slowly that the lens does not swing.

However, since the acceleration performance is different between an actuator and a VCM, the controller ( 1 ) poses the problem that the actuator and the VCM cannot provide the same acceleration even if the same current is applied to the actuator and the VCM. The controller ( 2 ) poses the problem that as the search time increases, the increase may affect access to a track.

The third embodiment therefore realizes a tax system in which "components in a high frequency band that an increase in the difference in acceleration power compared to that of an actuator, not included will be and a search time will not increase. "In short said the third embodiment carries a structural vibra minimized acceleration trajectory (SMART) control, which minimizes structural vibrations.

The SMART controller is used as a control system, that hardly generates vibrations through a high frequency band to be induced in a control object in an effort to  for example in the field of a magnetic disk unit Secondary resonance of a magnetic head caused by the search control is caused to master. The SMART controller is such that the occurrence of the residual vibration (1 to 2 kHz) a support spring, which is controlled by the fine control of the magnetic head fes (which is a frequency band of several hundred frequencies treated) cannot be fully controlled, even is suppressed during search control. That is, the control to be executed is not aimed at generated To suppress vibrations, but to be a target to present acceleration trajectory that has no vibrations causes.

Since the lens actuator 62 shown in Fig. 20 has no lens position sensor, no lens position signal can be generated. The VCM is therefore controlled according to the SMART control system that minimizes structural vibrations so that when the cart is moved, largely no pulse is applied to the VCM that triggers an abrupt acceleration or deceleration.

Let us consider the VCM as a movement model. The equation of motion is expressed as follows:

md ² x (t) / dt ² = (B1) .i (t)

where x (t) indicates the position of the VCM and i (t) indicates a coil current. If the position and speed of the VCM are used as quantities of a state, the state equation is as follows:

x (t) = Ax (t) + bi (t)

where x (t) indicates the position of the VCM. When rewriting, the equation of state becomes as follows:

Assuming that the environmental conditions for the model are expressed as follows:

a target path is given in the acceleration path control by the function x (t), which minimizes the following performance function:

In other words, the function x (t), which is "a change of a stream that hits the VCM within a seek time is to be used, minimized ", defines an acceleration track that minimizes structural vibrations is effective. That means the SMART control, the struktu Real vibrations can be minimized as the control system be considered, which is discussed below.

• 1. It is assumed that a seek time is T.
• 2. A current profile i (t) is set, the one Defines current that, if possible, does not have a high-frequency contains.

A procedure for solving the above expression according to the Variational calculation is at the core of the present invention not included. The detailed solution procedure will omitted, and only a solution is presented.

If it is assumed that a time t is normalized by a search time T, solutions such as the expressions below are provided, where a (tn) is an acceleration, v (tn) is a speed, x (tn) is a position and tn = t / T is determined. Target drive profiles are shown in Figures 21A through 21C. More specifically, Fig. 21A shows a drive profile at an acceleration, Fig. 21B shows a drive profile at a speed, and FIG. 21C shows a drive profile at a position.

a (tn) = L / T ^2. {120 tn ³ - 180 tn ² + 60 tn}

v / tn) = L / T. {30 tn ⁴ - 60 tn ³ + 30 tn ² }

x (tn) = L. {6 t ³ - 15 tn ⁴ + 10 tn ³ }

Thus, the target drive profiles can be relatively simple polynomials. It is easily possible the polynomials using a digital signal processor (DSP). For example, if a search operation a car is taken will be a target acceleration and target speed based on the position of the Car and a distance that the car will travel during the search operation is moved. A search stream based the results of the calculation are then fed to a VCM.

Finally, an optical disk unit of the fourth embodiment of the present invention will be described. Before the optical disk unit, the lens lock by the conventional lens actuator will be briefly described in connection with Fig. 22B.

FIG. 22B shows the configuration for controlling the conventional lens actuator forth. Referring to Fig. 22B, there are a base 201 , a carriage 202 , a lens actuator 204 , a VCM 205 , an objective lens 209 , an optical disk medium 213 , a position sensor 216 , a lens position sensor 217 , a photo detector 218 , a differential circuit 219 and Phase compensators 220 and 221 are shown.

In an optical disk unit, tracking control is performed with respect to a track row so that the objective lens 209 can irradiate a light spot on an intended track of the optical disk medium 213 . A feedback loop is established to give a final value of 0 on a tracking error signal provided by photodetector 218 . Incidentally, the tracking error signal contains noise resulting from any of the following adverse effects:

• 1. dislocations of a spindle motor and the optical disk medium 213 ,
• 2. an error in the position of a row of tracks a reference position,
• 3. other structural vibrations, or
• 4. Influence of an ID division.

Noise resulting from all of the above adverse effects from the displacements of the spindle motor and optical disk medium 213 has a low frequency and a large amplitude. Noise resulting from the error in the position of a row of tracks, the other structural vibrations and the influence of ID division has a high frequency and a small amplitude. In the optical disk unit, while controlling two mechanisms, a rough movement mechanism and a fine movement mechanism, by assigning different control frequencies to the mechanisms according to the features of the mechanisms, the dual servo control is applied.

In dual servo control, the lens actuator 204 is controlled by the feedback loop that handles the tracking error signal, while the VCM 205 is controlled by a feedback loop that handles the output of the lens position sensor 217 . Alternatively, as shown in Fig. 22B, the speed of the VCM 205 (differential of the output of the position sensor) can be fed back for the purpose of damping.

Due to the above configuration, the carriage 202 follows the movement of the lens 209 . A component with a large amplitude of an error signal, which indicates that a displacement brings an intended track out of the movable range of the lens actuator 204 , can be sent to the VCM 205 in the form of the output of the lens position sensor 217 . Thus, the combination of the lens actuator 204 and the VCM 205 forms a dual servo control system.

FIGS. 23A to 23C show a tracking error signal (denoted by TES), which is generated during the conventional scan, a driving speed of the VCM 205 and an output from a lens position sensor (lens position signal). Depending on the speed of the VCM 205 , the carriage 202 follows the movement of the lens 209 . Lens 209 is locked in the center of carriage 202 during the search.

In contrast, the optical disk unit of the fourth embodiment uses the lens actuator 62 described in connection with FIG. 20, but does not include a position sensor and a lens position sensor. FIG. 22A shows the configuration of the lens actuator 62 of FIG. 20 in the form of a block diagram in the same manner as FIG. 22B, which shows the conventional lens actuator. Referring to Fig. 22A, an optical disc medium 1, a VCM 15, a base 20, a carriage 30, a lens actuator 62, an objective lens L, a photodetector 218, a filter 223, phase compensators 220, 224 and 226, a low pass filter (LPF) 225 , a spring 230 and switches SW1 and SW2 are shown.

Differences of the optical disk unit of the fourth embodiment with respect to a conventional unit in hardware are that the position sensor and the lens position sensor are not included and that the lens actuator 62 is supported on the carriage 30 by the spring 230 . When the lens actuator 62 is supported on the carriage 30 by the spring 230 , there are the following differences from the conventional unit:

• 1. Due to the lack of bearings, there are no problems wanted frictional forces, and
• 2. The actuator 62 is provided with a restoring force (a force proportional to a displacement) so that it is returned to an equilibrium position.

Since the lens actuator 62 is supported by the spring 230 , a generated tracking error signal (TES) denotes an equilibrium position at which the acceleration force of the lens actuator 62 and the spring force are balanced. In other words, due to the use of the spring-loaded actuator, the tracking error signal becomes a signal that contains a component of a lens position sensor output from the beginning.

Figure 23D shows a tracking error signal generated in the present invention when the lens is moved alone with the VCM fixed. FIG. 23E shows a lens signal is generated by the lens actuator 62 having the above components. It can be seen from the two signals that the envelope of the tracking error signal with its bias component removed is used as the waveform of the lens signal. In the present invention, the tracking error signal from the components shown in FIG. 22A is passed through the low pass filter 225 to remove high frequency components. The phase compensator 226 then performs the phase compensation. This leads to an incorrect lens signal shown in Fig. 23F. If the wrong lens signal with its noise removed is used, the lens lens L can be locked by the lens actuator 62 during the search of the carriage 30 even though no lens position sensor is included.

Claims (10)

1. Optical storage device for reproducing information from and / or recording information on an optical storage medium ( 1 ) by irradiating a light beam, which is generated by a stationary optical unit ( 40 ) within a main body, onto the optical storage medium ( 1 ) by a carriage ( 30 ) moving in the radial direction of the optical storage medium ( 1 ) within the main body by a drive mechanism in a state in which the optical storage medium ( 1 ) loaded in the main body is rotated on which carriage ( 30 ) an actuator ( 62 ) for a lens is mounted, which collects the light beam on the optical storage medium ( 1 ), and which optical storage device does not have position sensors for detecting the position of the carriage relative to the main body and for detecting the position of the lens actuator ( 62 ) with respect to the carriage ( 30 ), with:
a Hüllkurvendetektionsmittel that with respect to the optical storage medium (1) detected during a search operation of the carriage (30) the envelope of a Spurverfolgungsfeh lersignals which is obtained from reflected light of the light beam coming from the optical storage medium (1), and
a lens signal generating means ( 225 , 226 ) for removing the displacement part of the detected envelope and then outputting a signal having a resultant envelope as a lens signal equivalent to a lens signal used to operate the lens actuator ( 62 ) in lock the center of the carriage ( 30 )
wherein during a search operation of the carriage ( 30 ) for the optical storage medium ( 1 ), the lens signal is used to lock the lens actuator ( 62 ) in the center of the carriage ( 30 ). 2. An optical storage device according to claim 1, comprising:
cutting frequency changing means ( 1003 , 1007 ) for temporarily adjusting the first and second cutoff or cutting frequencies of filtering means ( 164 ) arranged on a path of a signal reproduced from the optical medium, the second cutoff frequency being lower than that is the first cut-off frequency;
sector separation detection means ( 1004 ) for detecting separation of sectors of the optical storage medium ( 1 ) using an ID signal sent from the filter means ( 164 ) when the second limit frequency is set in the filter ( 164 );
storage means ( 38 ) for storing frequencies and sector separations associated with the positions in the radial direction of the optical storage medium ( 1 ); and
a detection means for detecting the type of the optical storage medium ( 1 ) based on a detected sector separation and data stored in the storage means ( 38 ). 3. An optical storage device according to claim 1 or 2, comprising:
position deriving means ( 1008 ) for deriving a position of a current track from data stored in the storage means ( 38 ) according to a detected sector separation, and means for experimentally setting a reproduction frequency associated with the derived track;
ID detection means ( 1010 ) for judging whether an ID recorded on the derived track of the optical storage medium ( 1 ) can be recognized at an experimentally set reproduction frequency;
reproduction frequency fine adjustment means ( 1011-1013 ) which, when an ID cannot be recognized, increases or decreases the reproduction frequency; and
track position finalizing means ( 1016 ) which, when an ID can be recognized at a tentative reproduction frequency or a fine reproduction frequency, finalizes a position of a current track in association with the reproduction frequency. An optical storage device according to any one of the preceding claims, further comprising track position detection execution means ( 1012 , 1013 ) which judges when the track position detection means ( 1014 ) cannot recognize an ID by performing a given number of times to raise or lower a reproduction frequency, that the type of the optical storage medium ( 1 ) is different and performs a track position detection associated with an optical storage medium ( 1 ) of a different type. 5. Optical storage device according to one of the preceding claims, characterized by
intercepting means ( 35 ) protruding from an edge of the carriage which is distant from a spindle motor ( 45 ) for rotating the optical storage medium ( 1 ) and extending in a direction parallel to a moving direction of the carriage ( 30 );
a photosensor means ( 7 ) which contains a light-emitting device ( 5 ) and a light-receiving device ( 6 ) and is arranged across a movement path of the intercepting means ( 35 ) and the incident light of which is intercepted by the intercepting means ( 35 ) only for a period during which the carriage (30) is arranged in an area (1 a) which is defined of the optical storage medium in the vicinity of an outer circumference; and
a carriage position specifying means (1601), which, when it is detected that the reflected light of the Fotosen sormittels is trapped by the scavenger (35) judges that the carriage has moved to the area (1 A). 6. An optical storage device according to any one of the preceding claims, further comprising:
a carriage initial movement means, when the power supply of the optical memory device (1) is switched on then, the carriage (30) (1 A) of the optical storage medium (1) moves into the area and the carriage at the location of a given number of times back and moved so that the interception and non-interception of incident light of the photosensor means ( 7 ) is repeated by the interception means ( 35 );
interception current detection means ( 1608 , 1623 ) for detecting a drive current in the carriage start moving means at the time when the incident light of the photosensor means ( 7 ) is intercepted by the movement of the interception means ( 35 );
non-intercept current detection means ( 1610 , 1617 ) for detecting drive current in the carriage initially moving means at the time when the photo sensor means ( 7 ) is placed in an non-intercepted state by the movement of the intercept means ( 35 ); and
a holding current calculating means (1624) for loading expected of a holding current, which is restriction means required for the Wagenanfangsbewe to the carriage (30) to keep within a range (1 A), drive current on the basis of an on which, by the Abfangstromdetektionsmittel (1608 1623 ) and a drive current detected by the non-intercept current detection means ( 1610 , 1617 ). 7. An optical storage device according to any one of the preceding claims, characterized by a laser output setting means that applies the holding current to the Wagenanfangsbe wegungsmittel and the carriage within the laser equipment gabeeinstellbereiches (1 A) holds and so executes the Laserausgabeein position. 8. An optical storage device according to any one of the preceding claims, further comprising: a differential current calculation means ( 170 ) for calculating a difference between a drive current detected by the interception current detection means ( 1608 , 1623 ) and a drive current through the non-intercept current detection means ( 1610 , 1617 ) has been detected; and new detection execution means which, when the differential current exceeds a given value, allows the carriage moving means ( 1702 ), the interception current detection means ( 1608 , 1623 ) and the non-interception current detection means ( 1610 , 1617 ) to re-execute the detection. 9. An optical storage device according to one of the preceding claims, comprising:
moderate acceleration means which, when a search operation of the carriage for the optical storage medium ( 1 ) is started, supplies a current to the drive mechanism for the carriage, which is used to smoothly accelerate the carriage ( 30 ); and
a moderate decelerator which, when the carriage ( 30 ) approaches a search target position during a search operation of the carriage ( 30 ) with respect to the optical storage medium ( 1 ), supplies a current to the drive mechanism for the carriage ( 30 ) which is used to slow down the carriage ( 30 ) gently. The optical storage device according to claim 8, wherein during a search operation of the carriage ( 30 ), the moderate accelerating means and the moderate decelerating means calculate a target acceleration and target speed based on a position of the carriage ( 30 ) and a distance by which the carriage ( 30 ) is moved during the search operation and supply a search current to the drive mechanism for the carriage ( 30 ) according to the calculation results.