FR2575857A1 - Optical information storage apparatus - Google Patents

Abstract

The invention relates to an optical information recording and reproduction apparatus. It includes a processor intended to record, reproduce or erase the information on an optical disc 93, a disc-type detector 81 intended in particular to determine the diameter of the optical disc, and a controller 82 intended to control the processor's process parameters as a function of the output signal from the detector. The latter reads an item of information recorded in advance on the optical disc, which item of information determines the type of this disc. Field of application: information storage on optical discs.

Description

 An optical information storage apparatus capable of supporting different types of recording media.

 Optical data storage means, a recordable optical disk of the type DRAW erasable optical disk type E-DRAW and a read optical disk, type ROM, used only in reproduction mode. In the case of the DRAW recordable type optical disk, the cavities corresponding to the information to be stored are formed on the surface of the disk by a laser beam and the stored information is read from a variation in the amount of reflected light. In the case of the erasable optical disk of the E-DRAW type, the laser beam causes a reversal of flux on the surface of the disk in order to record and erase information, and the recorded information is read by the magnetic effect. Kerr or the like. On the other hand, in the case of the ROM type reading disc, the cavities corresponding to the information are formed in advance and the information signal is read by means of a variation of the amount of light reflected from a laser beam. .

 One of these #disks is chosen depending on the use of the information to be recorded. The ROM type reading disc is used in case the information is determined in advance, mass production is necessary and the disc must be kept for a long time. The recordable disc of type DRAW is used in case the necessary number of discs is weak and the disc must be kept for a long time. The E-DRAW erasable disk is used in case the recorded information may later be erased and the disk is used as a temporary buffer.

 In this way, the disks can be used effectively. Moreover, whatever the different types of discs, their basic constitutions for recording and reproducing information are substantially the same; it is therefore requested to use a common training device.

 However, in this case, depending on the types of disks, there are differences between the reflection factors or the transmission factors of the surfaces of the disks and the differences affecting the reading principle, so that the output level of the signal reproduced in FIG. the signal reading system, in particular the output component of the information signal or the like, changes at least several tens of times.In the case of reproduction of information by the same reproduction system, there are problems such as that an extended dynamic range is required if the smallest reproduced signal is used as a reference, whereas the noise becomes important and the signal level becomes too weak in the case of a weak signal if the strongest signal reproduces is used as a reference, - and other.

 In addition, the differences in reliability and error rate of the reproduced information signals appear as a function of the respective disks.

 Thus, in the case where the same error correction circuit is used for all the disks, if the error correction circuit is designed according to the disk in which the error rate, before correction, is the higher, an over-specification appears for the disk with a low error rate before -correction.

In other words, since the error correction codes increase beyond what is necessary for the information signal, the redundancy also increases beyond what is necessary, which results in poor coding efficiency.

 A number of recording discs of various sizes (diameters), such as 30, 20 and 12 cm or the like, are currently used.

 These disks are used according to their application. The large disk is used in the case of recording information in large quantities. The small recording disk is used in the case where it is requested easy handling of the recording disk and the ease of wearing it.

 Until now, the same recording / reproducing apparatus can use only one recording disk size.

 This is due to the following reasons. In the case of recording predetermined information in the recording disk using light, if the rotational speed of the recording disk is set so as to make the recording rate of the signal constant to record, the linear velocity is proportional to the diameter of the recording disk, so that the length of each unit (bit) of information to be recorded is proportional to the diameter of the recording disk. Therefore, the light energy to be projected onto the unit area of the recording disk is inversely proportional to the diameter of the recording disk and the density of the recording on the disk is also inversely proportional to the diameter thereof.

 Therefore, when the same optical information recording / reproducing apparatus is used with a recording disc of a larger diameter than the recording discs usually used with this apparatus, the density of the light energy on the recording disc decreases, so that it may be difficult to properly record the information.

 As described above, only one recording disk size can be conventionally used in the same recording / reproducing apparatus. Consequently, in the case where several recording discs of different sizes are used, there is a problem the resolution of which requires having several recording / reproducing apparatus corresponding to the sizes of the recording discs.

 The object of the invention is to eliminate the disadvantages indicated above. The object of the invention is in particular to provide an improvement to an optical information recording / reproducing apparatus, and in particular to provide an optical recording / reproducing apparatus for recording, reproducing and steadily erasing information on different types of recording media. Another object of the invention is an optical information recording / reproducing apparatus capable of recording, reproducing and stably erasing information on recording media of different sizes or dimensions, and especially such an apparatus capable of detecting the type of recording medium.

 Another object of the invention is to provide an optical information recording / reproducing apparatus in which the stable recording, reproducing and erasing operations can be performed on several kinds of recording media, by the same device, using a simple principle without any use of any particular device.

 Another object of the invention is to provide a highly efficient apparatus for archiving information that satisfies both the preservation of resources (space saving) and the preservation (storage).

 Another object of the invention is to provide an optical information recording / reproducing apparatus in which the output level of the playback system signal can be stabilized in the case of reproduction on different types of media. recording using the same optical recording / reproducing apparatus, and even in the case of using any type of recording medium.

The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which:
Figure 1 is a perspective view of an optical disk apparatus to which the method according to the invention is applied;
Fig. 2 is a diagram of a circuit of the optical disk apparatus shown in Fig. 1;
Fig. 3 is a diagram showing the voltage values of a direct input terminal and an inverting input terminal of a comparator of the circuit shown in Fig. 2;
Fig. 4 is a diagram showing the identification of a disc;
Fig. 5 is a perspective view of another optical disk apparatus to which the method of the invention is applied;
Fig. 6 is a diagram showing examples of photo-switch connections of the apparatus shown in Fig. 5;
Fig. 7 is a diagram showing the identification of a disk;
Figure 8 is a schematic diagram of one embodiment of the invention;
Fig. 9 is a diagram showing an example of recording media for use in the above embodiment;
Fig. 10 is a flowchart showing the operation of the previous embodiment;
Fig. 11 is a schematic diagram of an embodiment of the optical information recording / reproducing apparatus according to the invention;
Fig. 12 is a plan view of a disk for use in the optical information recording / reproducing apparatus according to the invention;
Fig. 13 is a flowchart showing the disk type discrimination operation;
Fig. 14 is a diagram of a detector and disk sort circuit of an embodiment of the invention;
Fig. 15 is a diagram of a circuit used in one embodiment of the invention;
Fig. 16 is a schematic diagram of a current / voltage conversion circuit;
Fig. 17 is a schematic diagram of an embodiment of an optical information recording / reproducing apparatus according to the invention;
Fig. 18 is a flow chart of the operation of an optical information recording / reproducing apparatus according to the invention;
Fig. 19 is a schematic diagram of an example of an encoder for use in the invention;
Fig. 20 is a schematic diagram of an example of a decoder for use in the invention;
Fig. 21 is a diagram of a signal format used in the invention;
Fig. 22 is a schematic diagram of one embodiment of the invention;
Fig. 23 is a table giving various constants used in the case where the size of a recording disk is changed;
Fig. 24 is a flow chart of the operation of the embodiment shown in Fig. 22;
Fig. 25 is a vertical cross-section of a two-sided disk;
Fig. 26 is a schematic diagram of one embodiment of the invention;
Fig. 27 is a flowchart of two-sided disk type discrimination operations; and
Fig. 28 is a flowchart of the operations performed in the dual-disc recording mode.

 An optical disk apparatus will be described as an embodiment embodying a recording medium identification method according to the invention.

 Fig. 1 is a perspective view of an optical disk apparatus to which the invention is applied.

In FIG. 1, the reference numeral i designates a disc, the reference 2 designates a disc cartridge in which the disc I is inserted, the reference 3 designates guide rails along which the disc cartridge 2 is inserted into an apparatus. 4 is a reflecting stamp stuck on the disc cartridge 2. The reflection factor of the stamp 4 can be modified depending on the type of disc. For example, a reflective stamp having a reflection factor of 0% is pasted on a ROM-type disk. A reflective stamp having a reflection factor of 25% is pasted on a disk of the DRAW type.

A reflective stamp having a reflection factor of 50% is glued to a disk type E-DRAW, A photointerruptor 5 is provided.

 FIG. 2 is a circuit diagram of the optical disk apparatus shown in FIG. 14. In FIG. 2, reference numeral 7 is a light emitting diode, reference 6 is a current limiting resistor, the reference is 10 denotes a control transistor of the light-emitting diode 7, the reference 8 designates a bias resistor, the reference 9 designates a PIN-type photodiode, the reference 11 designates a pre-amplifier intended to amplify the received signal, the references 12 and 14 denote comparators and references 13 and 15 denote variable resistances.

 The operation of this embodiment will be described below with reference to Figures 1 and 2.

 When an input signal is applied to the base of the transistor 10, it is turned on so that a current flows and the light emitting diode 7 emits a constant amount of light. The light emitted by the diode 7 is reflected by the reflecting stamp 7 and received by the photodiode 9. The output signal of the diode 9 is amplified and subjected to a current / voltage conversion in the pre-amplifier 11.

The potentials of the respective inverting input terminals (-) of the comparators 12 and 14 are set at V1 and
V2 by the variable resistors 13 and 15. As shown in Figure 3, the potential V1 has a voltage value between an output value (Va) of the preamplifier 11 in the case where the reflection factor of the reflective stamp is 0 %, and an output value (Vb) of the pre-amplifier II in the case where the reflection factor of the reflecting stamp is 25%.

 The potential V2 has a voltage value between the output value (Vb) and an output value (Vc) of the pre-amplifier II when the reflection factor of the reflecting stamp is 50%. Comparators 12 and 14 compare the voltage values at the inverting input terminals (-) which have been established as mentioned above, to voltage values at the direct input terminals (c) connected to an output of the preamplifier 11. In the case of the ROM type reading disc on which the reflective stamp having a reflection factor of 0% is glued, there exists the relation Va <V1 <V2 Therefore, the two outputs of the comparators 12 and 14 take a low level.In the case of the DRAW recordable disc on which is glued the reflective stamp of a reflection factor of 25%, there is the relationship Vl <Vb <V2, so that the output of the comparator 12 takes a high level and that the output of the comparator 14 takes a low level. In the case of the erasable disk of the E-DRAW type on which is glued the reflective seal having the reflection factor of 50%, there exists the relationship V <V 2 <Vc 1 so that the two outputs of the comparator 12 and 14 take a level above. As mentioned above, three types of output signals are generated as shown in Figure 4, so that three different types of disks can be detected.

 Another method of identification will now be explained.

FIG. 5 is a perspective view of another optical disk apparatus to which the invention is applied and in which the elements assuming the same functions or having the same constitution as those of the elements of FIG. 1 are designated by the same references. digital. In FIG. 5, plates 16a and 16b forming a light shield are attached to the cartridge 2. When the disk is inserted, the optical paths of the photo-switches
Sa and 5b are interrupted by the plates 16a and 16b.

 FIG. 6 shows examples of connection of the light switches in the apparatus shown in FIG. 5. The reference numerals 17a and 17b designate light-emitting diodes; references 18a and 18b designate phototransistors; and references 19 and 20 refer to the output signals produced by the light switches Sa and 5b, respectively.

 Firstly, in the case where the disk 1 housed in the cartridge 2 is of the ROM reading type, unless the plates 16a and 16b forming a light shield are attached to the cartridge 2, the lights emitted by the diodes The light emitters 17a and 17b of the photointerrupters Sa and 5b are not interruptible, but arrive at the photo-transistors 18a and 18b when the cartridge is inserted, so that the two control signals 19 and 20 take a low level.

In the case of a recordable record of the type
DRAW, only the plate 16a is fixed to the cartridge 2 and the plate 16b is not fixed. In this arrangement, when the disk is inserted, the light of the light-emitting diode 17a of the photo-switch Sa is stopped by the plate 16a, so that the phototransistor 18a receives no light and the control signal 19 takes a level above. The control signal takes a low level in the same way as for the ROM type read disk.

In the case of an erasable disk of the type
E-DRAW, the two light-shielding plates 16a and 16b are attached to the cartridge 2 of the disk. By this arrangement, when the cartridge 2 is inserted, the lights of the light-emitting diodes 17a and 17b of the light switches Sa and 5b are stopped and no light reaches the photo-transistors 18a and 18b, so that the two control signals 19 and 20 take a high level. As described above, three types of output signals are generated as shown in Fig. 7 and three different types of disks can be detected.

 The type of disc can be detected by making concave portions instead of the light shielding plates.

 Another method of identification will now be explained.

 Fig. 8 is a schematic diagram showing an embodiment of the invention.

 A recording medium 21 can be loaded from the outside. A spindle motor 22 rotates the recording medium 21. An optical head 23 records data on the medium 21 or reproduces data therefrom. A focusing control and tracking circuit 24 causes automatic focusing and tracking operations to be performed on a light beam.

 A reproduced signal processing circuit 25 amplifies the reproduced signal from the recording medium 21 and demodulates it. A controller 27 adjusts the gains of the control circuit 24 and the processing circuit 25, respectively.

 A laser modulator circuit 26 modulates a laser beam which is used for recording data on the recording medium 21. An output value of the laser beam can be set by the controller 27.

 Fig. 9 is a diagram showing a recording medium for use in the optical information recording / reproducing apparatus.

 Information is recorded in the shaded area of the recording medium 21 and is reproduced from that area. Code information representative of the type of the recording medium 21 is recorded on an inner track 21a of the support 21.

 In the process of forming the pre-group on the recording medium, the identification information is recorded as a cavity on this pre-group by the physical formation of a hole in the holder 21. In recording the identification information of the medium during the production of the recording medium, this identification information can be detected when using the recording medium and the recording / reproduction conditions can be suitably established according to the result of this detection. Thus, the optimal recording and reproduction operations can always be performed depending on the type of recording medium to be used.

In other words, when the recording medium 21 is used, the identification information of the medium recorded on the pre-group is read first in order to be identified, which adjusts each circuit so that it is suitable for this purpose. recording medium.
The operation of the above-described embodiment will now be explained.

 Fig. 10 is a flowchart showing the recording medium type discrimination process performed by the controller 27.

 The controller 27 always checks whether or not the recording medium has been loaded into the apparatus (step S1). If the answer is YES, the spindle motor 22 starts to rotate (step S2) to rotate the spindle 22. support at a predetermined speed. Laser power, servo gain, and signal gain are set at predetermined values P1, As1, and A1 so that the media type identification information 21 recorded on the pregroup can be reproduced (step S3 ). At the same time, the optical head 23 accesses the inner track 21a of the recording / reproducing area (step S4). Type identification information is recorded on track 21a.

 After completion of the access (step SS), the type identification information of the medium 21 is reproduced (step S6) and the reproduced signal is transmitted to the controller 27 via the signal processing circuit 25 reproduced.

 The controller 27 discriminates whether the medium 21 is of the E-DRAW, DRAW or ROM type (steps S7, S8 and S9) based on the code data derived from the reproduced signal). Then the laser power, servo gain and signal gain, which are optimal for the discriminated recording medium, are established (steps S10, S1 and S12). If the recording medium does not correspond to any of these three types (step S13), the process stops.

 Another identification method will be described later.

 In this example, the case in which a discrimination zone comprising a reflector is provided on the disk will be explained.

 Fig. 11 is a diagram of an embodiment of an optical information recording / reproducing apparatus according to the invention. In FIG. 11, the numeral # e 31 designates an optical head, the reference 32 designates a laser source, the reference 33 a collimation lens intended to establish the parallelism of the laser beam coming from the source 32, the reference 34 designates a optical beam splitter for reflecting the light coming from a disk 37 on which it is reflected, the reference 35 designates an objective, and the reference 36 designates an actuator for controlling the lens 35 to allow the laser beam to pass through the lens for focusing and tracking at a predetermined position on the surface of the disc 37. The reference numeral 37 designates an analyzer, the reference 39 designates a condensing lens, the reference 40 designates a device photosensitive and the reference 41 designates a spindle motor for rotating the disc 37 placed on a turntable e 42 by means of a flange 43. During a recording operation, an image information signal is converted into a photo signal by the laser source 32 from the laser modulator 44.

The beam or laser beam passes through the collimating lens 33, the optical deflection divider 34 and the object 35 and is focused on the disk 37 where it is recorded. In a reproduction operation, a laser beam of constant power is produced by the source 32 and projected onto the disk 37 in a manner similar to that of the aforementioned recording method.

The beam or laser beam reflected by the disc 37 passes through the objective lens 35, the deflection optical divider 34, the analyzer 38 and the condenser 39 and arrives at the photosensitive device 40. The amount of reflected light is converted into a light source. electrical signal by the device 40 and is reproduced in the form of image information by a demodulator circuit 45. At the same time, the output signal of the device 40 is also transmitted to a control circuit 46 focusing / tracking and it controls the objective 35 via the actuator 36, in order to assume the functions of focusing control and tracking.In the case of an erasable disk type E-DRAW, for the erase operation, a laser beam of constant power is produced by the laser source and projected onto the disk 37 in a manner similar to that described for the previous recording operation, thus erasing the recorded information r disk 37. The optical head 31 is moved in the radial direction of the disk by means of a feed motor 47. A control circuit 48 of the advance motor 47 controls the position of the optical head 31 as a function of the output signal of a head position sensor 49.

A spindle motor control circuit 50 rotates the motor 41 at a disk type dependent speed, which is indicated by a controller 51 to which a disk type representative signal is transmitted by a disk type detecting circuit 52. . The controller 51 controls the synchronization of the aforementioned circuits.

 Fig. 12 is a plan view of the disk used in the optical information recording / reproducing apparatus according to the invention. The reference numeral designates the disc and the reference numeral 53 designates a discrimination zone consisting of a reflector applied to the surface of the disc. The reflection factor of this reflector can be changed depending on the type of disc.

For example, the reflection factor is set to 0% in the case of a ROM type reading disc, 25 in the case of a DRAW type recordable disc, and 50% in the case of a disc erasable type E-DRAW.

 The discrimination operation will now be described with reference to the operation flowchart, which operation aims to determine the type of disc as shown in FIG. 13.

 First, the disk 37 is placed on the turntable 42 and the power is turned on for the initialization of the apparatus so that the spindle motor 41, the disc 37 being set, begins to rotate ( step 814). The advance motor control circuit 48 then controls the feed motor 47 in accordance with the access instructions from the controller 51 so that the optical axis of the objective 35 of the optical head 31 comes overhead. the discrimination zone 53 (step S15). Then the laser source 32 is turned on (step S16) and the servo loop for the autofocus is closed so that the autofocus execution is executed (step S17). It is now assumed that the reflection factor the reflector stuck to the disk is set to a range within a range for executing the autofocus operation. The beam or laser beam produced by the source 32 passes through the collimating lens 33, the optical deflection divider 34 and the lens 35 and arrives on the reflector 53 of the disk 37. The laser beam reflected by the reflector passes through the beam. 35, the divider 34, the analyzer 38 and the condenser 39 and arrives at the photosensitive device 40. The amount of reflected light is converted into an electrical signal by the device 40. The type of disk is then discriminated by the circuit 52 of disc type detection (step 818). Based on the control signals from the controller 51, the laser modulator 44 and the spindle motor control circuit 50 adjust the laser power and the rotational speed to the optimum values for the disk placed on the platen 42. In the same time, the controller 51 transmits control signals to the control circuit 46 for focusing / tracking and the circuit 45 of the demodulator, thus switching to optimum values (step S19) the automatic focus gain, the automatic tracking gain and the signal gain. Then the optical head 31 is moved and the reproduction begins.

 FIG. 14 is a schematic diagram of a disk type detecting circuit of this embodiment, the circuitry of which the components assuming the same functions or having the same constitution as those of the components shown in FIG. 2 are designated by FIG. the same numerical references. In Fig. 14, the reference numeral 54 designates a bias resistor and the reference 55 is a PIN type photodiode for receiving light reflected from a reflective material.

 Since the identification method is, in practice, substantially the same as that illustrated in FIG. 2, it will not be described again. In the apparatus using a transmission type disk in which information is reproduced by a transmitted light, the similar operation can be performed by the presence of the discrimination zone which is then made of a transparent material whose factor of transmission differs according to the type of disc surface.

 The modification of each of the control parameters by the use of the disk identification method indicated above will now be described.

 Fig. 15 is a diagram of an embodiment of the invention.

 A PIN type photodiode 61 is incorporated in an optical sensor and constitutes a photoelectric conversion device for converting information about a quantity of light that varies as a function of individual information recorded on the disk into current information. A voltage amplifier 62 is an example of the signal reading system and converts the current of the information signal into a voltage. A feedback resistor 63 reduces the gain of the voltage amplifier. A first analog switch 64 is used to establish a connection between an input and an output of the voltage amplifier 62 through a second feedback resistor 67 and this switch is constituted by a field effect transistor. A second analog switch 68 is used to establish a connection between the input and the output of the voltage amplifier 62 through a third feedback resistor 71 and is also constituted by a field effect transistor. The reaction resistors 63, 67 and 71 are mutually equivalent and connected in parallel.

In addition, resistors 66 and 70 and diodes 65 and 69 are provided.

 Further, a control signal 72 of the first analog switch is provided to the first analog switch 64. A control signal 73 of the second analog switch is provided to the second analog switch 68.

 It is now assumed that the disk type is identified in such a way that the two control signals 72 and 73 take a low level when an erasable disk of the E-DRAW type is loaded into the apparatus, the command 72 takes a high level and the control signal 73 takes a low level when a recordable disc of the DRAW type is loaded, and that the two control signals 72 and 73 take a high level in the case of a playback disc ROM type.

 When the disk of type-E-DRAw is loaded, the two control signals 72 and 73 take a low level, so that both analog switches 64 and 68 open and only the resistor 63 of feedback drives.

 When the DRAW type disk is loaded, the control signal 72 takes a high level and the control signal 73 lowers, so that the first analog switch 64 closes to make the second feedback resistor 67 conductive.

However, since the second analog switch 68 opens, the third feedback resistor 71 is not turned on. Therefore, the two reaction resistors 63 and 67 are made conductive and the overall value of the feedback resistance is lower than that which was present in the case where the optical magnetic disk was inserted, so that the gain of the reading system signal is reduced.

 When the ROM type disk is loaded, the two signals 72 and 73 take a high level, so that the two analog switches 64 and 68 are made conductive to also make the second and third feedback resistors 67 and 71 equally conductive.

As a result, the overall value of the feedback resistors decreases and the gain of the signal reading system further decreases.

 Fig. 16 is a schematic diagram illustrating the current-to-voltage conversion operation.

The operational amplifier 74 shown in FIG. 16 corresponds to the voltage amplifier 62 shown in FIG. 15. In FIG. 16, when a current Io is applied, an output voltage Vo appears and is expressed in the same manner. next:
V0 = -A. Io. R / <1 + A) where A is the gain of the operational amplifier 74.

It appears from this expression that when the input current changes, by changing the value of a resistance
R Reaction, one can maintain constant the output voltage of the amplifier.

 In general, the current value of the signal reproduced in the PIN-type photodiode 61 increases successively with, in order, the optical magnetic disk, the optical disk and the ROM disk.

In the previous embodiment, the gain of the signal reading system successively decreases, in order, with the optical magnetic disk, the optical disk and the ROM-type disk. Therefore, in this embodiment, even when using any of the optical, optical, and ROM magnetic discs, the output level of the signal reading system is always at a constant value.

 The foregoing embodiment aims to stabilize the output level of the signal reading system by changing the feedback resistances of the voltage oscillator 62 to convert a current value to a voltage value depending on the type of disk.

On the one hand, in the case where the dynamic range of the voltage amplifier 62 permits, the output voltage is divided by a resistor and the value of the dividing resistor, in this case, can be varied as a function of type of disk. According to this design, the output voltage can be stabilized regardless of the type of disc.

 The case where the speed of rotation of the disc is changed according to the type of disc will now be described.

 Fig. 17 is a diagram of an embodiment of the optical information recording / reproducing apparatus according to the invention. In Fig. 17, an optical head 84 accesses a disk 93 while moving in the radial direction. Reference numeral 85 designates a laser source; reference 86 designates a collimating lens intended to establish the parallelism of the beam or laser beam of the source; 87 denotes an optical splitter for reflecting light from disk 93 by reflection; and numeral 88 designates a lens that can be moved both in the vertical direction indicated by the double arrow A to perform the focus control of the laser beam when the recording, reproducing, and erasing operations are performed on the disc 93, and in the horizontal direction, indicated by the double arrow B, to perform the tracking command of the laser beam. In. In the recording operation, a laser or laser beam is produced by the laser source 85 which is controlled by a laser modulator (not shown) and this laser beam passes through the collimator lens 86, the optical divider 87 and the objective 88 and is projected on the disc 93 so as to perform the recording.

 In the reproducing operation, a constant power laser beam or beam is produced by the laser source 85 and is projected onto the disk 93 in the same manner as in the recording process. The laser beam reflected by the disk 93 goes to through lens 88, optical splitter 87, analyzer 89 and condenser lens 90 and arrives at photosensitive device 91. The amount of reflected light is converted into an electrical signal by device 91.

This electrical signal is transmitted to a signal processor 92 so that it is reproduced. In the erasing operation, a laser beam or beam of constant power is produced by the laser source 85. This laser beam passes through the collimating lens 86, the optical divider 87 and the objective 88 and is projected onto the disc 93 so that the information recorded on it is erased.

 A signal representative of the type of disk is transmitted to a controller 82 by a disk type detector 81. The controller 82 then transmits to a control circuit 83 of the drive motor of the disk a signal representative of the speed of rotation of the disk according to the type of the disk, so as to adjust the speed of rotation of the disk 93. The latter is loaded on a turntable 97 on which it is held by a flange 95 and is rotated by a disk drive motor 96 connected to the control circuit 83.

 Although one of the aforementioned disk type identification methods is used in the disk type detector 81, it is also possible to use another method. For example, it is assumed that the process of Figure 5 is used. In the case of a ROM type reading disc, the two control signals 19 and 20 (FIG. 6) which are transmitted to the controller 82 by the detector 81 take a low level. In the case of a recordable disk of the DRAW type, the signal 19 takes a high level and the signal 20 takes a low level. In the case of the erasable disk of the E-DRAW type, the two signals 19 and 20 take a high level.

As previously described, three types of control signals may be emitted
Fig. 18 is a flowchart illustrating the operation of the optical information recording / reproducing apparatus according to the invention. This operation starts with replacing the disc and turning on the power. First, the disk is loaded (step S20) and it is checked whether the disk has been loaded completely or not (step 21). If the answer is YES, the type of disc is detected by the detector 81 and the control signals 19 and 20 are emitted (step S22-). Then, the control signals 19 and 20 are checked to determine whether the disk is of the ROM type or not (step S23). In the case where the disk is of the ROM type, that is to say when the two signals 19 and 20 are at the low level, a signal representative of a rotational speed R1, corresponding to this disk, is transmitted from the controller 82 to the control circuit 83 of the disk drive motor (step S26).

If the disk is not of the ROM type, a check is made to know whether it is of the DRAW type or not (step S24). In the case of a disk of the DRAW type, namely when the control signal 19 is at a high level and the signal 20 at a low level, a signal representative of a rotation speed R2 corresponding to the disc of FIG. type DRAW, is issued (step S27). If the disk is neither of the ROM type nor of the DRAW type, a check is made to know whether the disk is of the E-DRAW type or not (step S25). In the case of a disk of the E-DRAW type, that is, when the two control signals 19 and 20 are at a high level, a signal indicating a rotational speed R3 corresponding to the E-DRAW-type disk is emitted (step 828). When the disk is not of the type
ROM neither of the DRAW type nor of the E-DRAW type, it is determined that an error has occurred (step S29) and an error indication is displayed, or a similar operation is performed. Practical examples of the rotational speeds used in the reproduction, recording and erasing operations of ROM, DRAW and E-DRAW type disks are given in Table I # below.

TABLE I

<tb><SEP> Reproduction <SEP> Recording <SEP> Erasing
<tb><SEP> Type <SEP> ROM
<tb><SEP> (R1)
<tb><SEP> (rpm) <SEP> 1 <SEP><SEP> 800
<tb> ype <SEP><SEP> DRAW
<tb><SEP> (R2)
<tb><SEP> (rpm) <SEP> 1 <SEP> 200 <SEP> 700
<tb><SEP> T
<tb> Type <SEP> E-DRAW
<tb><SEP> (R3)
<tb><SEP> (trimin) <SEP><SEP> 900 <SEP> 900 <SEP> 700
<tb><SEP> ... <SEP> ~~ <SEP> ~
<tb> Power <SEP> laser
<tb> on <SEP> the <SEP> disk
<tb><SEP> (mW) <SEP> 2.0 <SEP> 7.0 <SEP> 7.0
<Tb>
The control circuit 83 of the disk driving motor varies the rotational speed, for example by controlling the switching of a crystal resonator of a reference clock oscillator, by controlling the switching of a dividing circuit of Frequency, or by performing a similar operation based on a signal from the controller 82.

 The modification of the possibilities of an error correction circuit according to the type of disc will now be described.

 Fig. 19 is a schematic diagram showing encoders of one embodiment of the invention.

 The embodiment of Fig. 19 includes a buffer memory 101 for temporary storage of an information signal; a first encoder circuit 102 for producing a first error correction code; a second encoder circuit 103 for producing a second error correction code; a first switch 104 for switching between the first and second encoder circuits 102 and 103; a second switch 105 for switching between the output of the buffer memory 101 and the output of the first or second encoder circuit 102 or 103; a modulator 106 for modulating the signal from the buffer memory 101 and the signal from the encoder circuit 102 or 103 switched by the switches 104 and 105; and a laser driver 107 for controlling a beam or laser beam (not shown) from the modulated information signal and recording the information on the disk.

 Fig. 20 is a schematic diagram illustrating a decoder of an embodiment of the invention.

 In Fig. 20 there is provided a demodulator 108, a first error correction circuit 109, a second error correction circuit 110, a switch 111 and a buffer 112.

 The operation of this embodiment will now be described. In this case it is assumed that the disk type identification method shown in Figures 5 and 6 is used.

 The explanation will now focus on two disks with different characteristics.

First, in the case of using a disk in which the error rate of the original information is high (for example optical magnetic disk), the control signals 19 and 20 actuate the first switch 104 and switch it to the side a (figure 6).
The data is transmitted from the buffer 101 to the demodulator 106 and the first encoder circuit 102 at a constant bit rate during the period T3 shown in Fig. 21. In this case, the second switch 105 is connected to the d side. At the expiration of the period T3, the switch 105 is connected on the side c and error correction codes P2 and P1 are transmitted to the modulator 106 by the second encoder circuit 103.

Data and error correction codes
P2 and P1 mentioned above are transmitted repeatedly; in other words, the configuration shown at B in Fig. 21 is repeated so that predetermined information is recorded on the disk.

On the other hand, when using a disk whose original information error rate is low (for example an optical disk), the switch 104 is connected to the b side. The data is applied to the modulator 106 and the first encoder circuit 102 during a period T2 and the data can be transmitted to the modulator 106 via the switch 105 without passing through the second encoder circuit 103. At the end of the period T2, the switch 105 is switched to the c side and the error correction data and code P1 is repeatedly applied to the modulator 106 in accordance with a configuration indicated at A in Fig. 21, so that this information is recorded on the disk
In the reproduction operation, in the case where the error rate of the original information is small, the switch 111 is connected on the f side by the control signals 19 and 20 and the signal demodulated by the demodulator 108 is subjected to an error correction by the first error correction circuit 109, according to the format A of FIG. 21.

 On the other hand, when the error rate of an original piece of information is high, the switch 111 is switched on the e side and the error correction, using the second error correction code P2, is also performed first by the first error correction circuit 109. In the next step, the correction is again performed by the second error correction circuit 110 on the basis of the format B of FIG. 21, with respect to the data area, so that the correction is executed in such a way that more complete. The corrected information signal is transmitted to the buffer 112 for the signal output device reproduced in the next step.

 We will now describe the change of the control parameters according to the size or size of the disk.

 Fig. 22 is a schematic diagram of one embodiment of the invention.

 A photo-switch PI3 detects whether a recording disk 130 has been loaded or not. The optical path of this switch is cut in the case of the presence of a recording disk, even of minimum size. Photo-switches PI2 and PI1 detect the size (diameter) of the recording disc 130 and are similar to those used in conventional audio recording and playback apparatus.

 A controller 122 adjusts the power of the laser (light power) and the gain of a focus control and tracking circuit 123 as a function of the disk size detected by the photointerruptors PI1 to PI3.

 The circuit 123 controls the focusing and tracking.

 The light reflected by the recording disk 130 is detected by a photo-sensor 127 and a current corresponding to the reflected light is emitted by the photo-sensor 127. The current is converted into a voltage and the voltage is amplified and demodulated. by a reproduced signal processing circuit 124. On the one hand, signals corresponding to the focus and tracking deviations of the reproduced signal are transmitted to the focusing control and tracking circuit 123.

 A laser modulator circuit 125 varies the power of the laser at the record according to an instruction from the controller 122.

 An optical head 129 focuses a beam or laser beam from a laser source 128 onto the recording disk 130 by means of an objective lens 126. The light reflected by the recording disk 130 is received by the photo sensor 127 .

 The operation of this embodiment will now be described.

 An example of the case in which the speed of rotation of recording discs of different diameters is kept constant will be explained. The apparatus is set for conditions suitable for recording on three types of recording discs having the same sensitivity and different dimensions (for example recording discs of diameters of 30, 20 and 12 cm), respectively.

 These conditions are determined so as to optimize the recording rate, the production of information, the power of the laser and the gain of the focusing and tracking control circuit. Optimization of the recording / reproduction rate is necessary to achieve optimum recording density. Laser power optimization is necessary to establish optimal recording power.

 By detecting the photo signal, on the one hand, the focusing and tracking control is executed.

Therefore, when the laser power changes, the levels of the difference signals for the detection of the state of the focus and the state of the tracking also vary, so that it is necessary to optimize the gain. of the focus control and tracking circuit.

 In addition, for the three sizes of recording discs indicated above, the case in which there is a recording area extending from the position 5 mm to the inside the end (or outer periphery) of the recording disc 130 to the position corresponding to half the radius of the disc 130.

 In Fig. 23, which is a table showing various constants associated with the various sizes of disks, it is assumed that the rotational speed of the recording disk 130 is 900 rpm and that the minimum length of a bit (mfiSele unit d information) is 1 ssm.

 Fig. 24 is a flow chart of the operation of the embodiment illustrated in Fig. 22.

 First, when the power is turned on or when the recording disc 130 is removed from the apparatus, the operation cycle begins.

it is checked whether the recording disk 130 has been loaded or not according to the signal coming from the photointerruptor PI3 provided inside the device
(Step S30). If the disk 130 has been loaded, the signals from phato-interruq ~ urs PI2 and PI1 are introduced (step -S31).

When the two optical paths of photointerruptors PI2 and PI1 are cut, this means that
the loaded recording disk has the maximum diameter (D1) (step S32). In this case, the rate of
registration / reproduction is established at CL1 (step 534)
The laser power is set to P1 (step 535). The
servo gain of the focus control and tracking circuit 123 is set at G1 (step S36).

When the optical path of photo-switch PI2 is cut off and photo-switch PI1 receives light, it is determined that the diameter of the loaded recording disk is D2 (step S33). Therefore, the recording / reproduction rate is set at CL2 (step S37). The power of the laser is set to P2 (step S38). The servo gain of the focus control and tracking circuit 123 is set to
G2 (step S39).

 When the diameter of the recording disk is neither D1 nor D2, it is established that the diameter of the disk is the minimum. Therefore, the recording / reproduction rate is set at CL3 (step S40). The laser power is set to P3 (step S41). The servo gain of the control circuit 123 is set to G3 (step S42).

 The recording / reproduction rates CL1 to CL3 are established by switching a resonator to a reference clock oscillator or by a frequency division ratio or the like in the circuit 124 for processing the reproduced signals and in the circuit 125 of the laser modulator. The power of the laser is dimmed with respect to a reference value of the laser power control. The servo gain is switched by variation on circuit resistances, or the like.

 In the above embodiment, the laser power is constant for recording discs of the same size; however, it may vary depending on the radius of the recording disc used. In this case, a switching is performed on a variable power range of the laser depending on the diameter of the disk.

On the one hand, the servo gain of the processing circuit 124 is also modified in association with the variation of the power of the laser. For this purpose, an automatic gain control or the like is used.

Figure 23 shows examples of numerical values used in this case. Other numerical values other than those indicated may be used.

 So far, two-sided disks have been designed so that both sides are of the same type of disks. For example, two-sided recordable discs (DRAW type disks), two-sided playback discs, used only for reproduction (ROM-type discs), and two-sided erasable discs (discs of the type) are known. type E-DRAW).

 Recently, efforts have been made to reduce the number of documents and the efficient use of office space by implementing an electronic filing apparatus using optical discs.

 The use of two-sided optical disks of the conventional type makes it possible to reduce the number of documents and to use spaces effectively, to a certain extent, because their memory capacities are large.

 However, in the case of the DRAW type recordable disc, after information has been recorded, information can not be rewritten in the same memory position. Therefore, if temporary information is also recorded, the number of recorded discs is believed and there are problems which thwart the efficient use of spaces and the saving of resources.

 In addition, the erasable disk of the E-DRAW type poses a conservation problem. For example, this E-DRAW type disc can not withstand a long retention period of 20 to 30 years and it poses a problem that is unsuitable for long-term preservation given its rewriting property. .

 The reading disk of the ROM type poses as a problem a limitation of its field of use as an information archive disk, because it does not allow the recording of new information.

 The disk encompassing different types of recording media will now be described.

 Fig. 25 is a vertical section of a disk used in the present invention.

 A two-sided disk 131 has a thin superficial photomagnetic film (hereinafter referred to as an EXDRAW recording surface) 132 and a recordable surface (hereinafter referred to as a DRAW surface) 133. The E-DRAW 132 erasable recording surface and the DRAW 133 recordable surfaces are individually formed by the use of well-known technology and can be easily integrated by gluing in the same way as in the conventional two-sided disc.

 Fig. 26 is a schematic diagram of one embodiment of the invention.

 In FIG. 26, an optical head 139 comprises a laser source 140, a collimation lens 141 intended to establish the parallelism of the beam or laser beam of the source 140, an optical splitter 142 and a lens 143.

The latter is designed so that it can be moved by one actuator at a time in the vertical direction as indicated by the double arrow A, to focus the laser beam on the disk 131-, and in the horizontal direction as indicated. by the double arrow B to track the laser beam.

 The optical head 139 also includes a capacitor lens 149, an analyzer 145 which is used only for information reproduction, a photosensitive device 146 and a signal processing circuit 147.

 The autofocus and automatic tracking systems may be a well-known astigmatic system, a three-beam system, or the like, and therefore will not be described in detail. A spindle motor 148 rotates the loaded disk 130 on a platen 150 on which it is held by a flange 151.

 A disk type detector 134 detects the type of disk (ie whether it is a ROM disk, a DRAW disk, an E-DRAW disk, etc.) and delivers to a controller 135 of disc a signal representative of the type of disc. In this case, detector 134 detects the type of disk by the method described below or by a similar method. The controller 135 controls the entire disk apparatus and transmits to a laser modulator circuit 136 a laser power instruction corresponding to the sensed disk type to enable the power of the semiconductor laser 140 to be adjusted.

 A signal from the photosensitive device 146 is processed by the signal processing circuit 147 and, according to this signal, the focusing and tracking operations are controlled by a circuit 144. The gain of the control circuit 144 is switched. depending on the power of the laser.

 In Fig. 25, an optical head unit 153, placed above the disk 131, has substantially the same constitution as the optical head unit 152 shown below the disk 131 in Fig. 25. an independent mechanism is required head access for moving the optical heads 139 and 139 'in the radial direction of the disk 131, respectively. Such a mechanism of access of the heads can be achieved by the independent implementation of well-known linear motors, or similar devices associated with the optical heads 139 and 139 ', or by the integration of the optical heads 139 and 139' in order to The disc type detector 134 is constructed in such a way that marks corresponding to the types of discs on both sides of the two-sided disc 131 can be glued to the cartridge containing the disc. disk 131, or that the disk itself and these marks can be detected optically or mechanically by a sensor.

 The operation of this embodiment will now be described.

 Fig. 27 is a flowchart for identifying the type of two-sided disk.

 First, a check is made to see whether the two-sided disk 131 has been loaded into the disk drive apparatus, or not, this control being performed by a sensor (not shown) (step S43).

After the disk has been loaded, the disk type detector 134 informs of the disc type detection on the upper / lower side of the disk 131 (step S44)
A type signal is received from the disk type detector 134 (step S45). This type signal is also transmitted to a system controller (not shown) (step S46).

The type of disc detected is displayed in a console of the apparatus (not shown) (step S47).

 Fig. 28 is a flowchart illustrating the recording mode on a two-sided disk.

 After the two-sided disk recording mode has been set (step S48 '), the disk controller 135 transmits to the apparatus controller (not shown) a signal representative of the disk type on each of the faces upper and lower of the two-sided disk 131 which is loaded, namely a signal representative of an erasable disk of the E-DRAW type or a recordable disk of the DRAW type. The system controller (not shown) displays the type of disk on a display device located on the operator's console, thereby attracting the attention of the operator. In this case, it is assumed that the upper face of the two-sided disk 131 constitutes an E-DRAW erasable disk and that the lower face constitutes a DRAW recordable disk, to facilitate the explanation.

 A check is then made to determine whether the storage mode designated by the operator is temporary storage or permanent storage (step S48).

For example, if it is now assumed that the operator is doing an image editing job, the operator first chooses the temporary storage mode of the optical disk apparatus. Thus, an order representative of the temporary storage mode is transmitted to the disk controller 135 (steps S49 and S50). The disk controller 135 generates an upper optical head unit wait and access command signal 153 of Fig. 26 (step S51) .The sampled image data to be edited is recorded successively on the upper surface ( Erasable disk E-DRAW) of the two-sided disk 131 (step S52) and this recording operation is repeated until the data is completely stored (step S53).

In other words, the surface of the erasable disk
E-DRAW is used as the working image memory area.

 After the image data corresponding to the edited result has finally been determined, it is permanently recorded. In this case, the storage of the optical disk apparatus is set in the permanent mode by the operator. Thus, a permanent storage mode instruction is transmitted to the disk controller (steps S54 and S55) and the lower optical head unit 152, corresponding to the lower face (DRAW recordable disk) of the two-sided disk 131 of FIG. 26 begins the automatic focusing, automatic tracking, access and the like operations (step S56). The data resulting from the editing, mentioned above, is recorded at a predetermined address of the disk (step S57) and the recording operation is repeated until the data has been completely stored (step S58).

 For the E-DRAW erasable disk used as the working memory area, the erasure of the stored information is requested or this information is erased automatically, as necessary, after the job has been completed.

 In the case where the thin photomagnetic film is used as an erasable disk E-DRAW, it is necessary to adjust to several hundreds or thousands of oersteds the amplitude of the bias magnetic field which is inverted in the direction perpendicular to the surface of the disk during the save or erase operation. This can be achieved by mounting in opposition to electromagnets or permanent magnets well known in the optical head so that the surfaces of the disk pass between them.

 With this structure, the type of disc to be used is automatically selected according to the chosen mode of temporary storage or permanent storage of data, so that the optimal method of use, corresponding to the recording medium r can be established so safe. In addition, since two optical head units correspond to the respective surfaces of the disk, the media changeover time can be saved.

In addition, by implementing only one two-sided disk, the system can be effectively used with a single external memory device.

In the previous embodiment, there is described a two-sided disk constituting the erasable disk type E-DRAW and the recordable disk type
DRAW. However, the same principles can be applied to a two-sided disk constituting an erasable disk of the E-DRAW type and a reading disk of the ROM type.

In other words, in general, the operating system (OS) or manual, format or other similar parameter of the system can be registered preliminary on the ROM disk. In this case, the operator can effectively use the system with a single two-sided disk. In addition, it is the same for a two-sided disc constituting a reading disc of the ROM type and a recordable disc of the DRAW type.

In the case where the erasable disk is used
E-DRAW as a buffer, it is convenient to use it as an electronic mailbox of a Local Area Network (LAN). In general, the electronic mail is automatically recorded once on the erasable E-DRAW disk and the operator then reads it and can save the necessary information by uploading it to the DRAW recordable disk when necessary. .

 It goes without saying that many modifications can be made to the apparatus described and shown without departing from the scope of the invention.

Claims (23)

 An optical information storage apparatus, characterized in that it comprises processing means for performing a recording or reproducing or erasing process on an optical recording medium (37) of information, means for detecting the type of optical information recording medium, and means (51) for controlling the processing parameters used by said processing means in response to an output signal of the type detection means.  2. Apparatus according to claim 1, characterized in that the optical information recording medium comprises a recording medium of the type only used for reproduction (ROM), the recordable type (DRAW) and the erasable type (E -draw).  3. Apparatus according to claim 1, characterized in that the type detection means read an identification information previously recorded on the optical information recording medium, by said processing means, and thus detect the type of said support.  Apparatus according to claim 1, characterized in that the type detection means project an optical beam onto labels (4) having different reflection factors or transmission factors, which labels are affixed in advance on the recording medium by said processing means, and detect the amounts of reflected light or the amounts of light transmitted by said labels and thus the type of said medium.  5. Apparatus according to claim 1, characterized in that the type detection means comprise means for light emission and photo-detection (7, 9) and in that a light is projected by the means of light emission on labels (4) having different reflection factors or transmission factors and affixed in advance to a cartridge (2) in which the recording medium is housed, the quantities of reflected light or the quantities light transmitted by said tags being detected by the photo-detection means to thereby determine the type of medium.  Apparatus according to claim 1, characterized in that the type detection means detect the state of a concave or convex portion formed in a cartridge in which the recording medium is housed, thereby to detect the type of the support.  7. Apparatus according to claim 3, characterized in that the processing means comprise a movable head (23) that they move to a predetermined position when the type of support (21) is detected.  8. Apparatus according to claim 1, characterized in that the control means comprise gain control means for adjusting the gain of a signal reading system forming part of the processing means.  Apparatus according to claim 8, characterized in that the gain control means changes the value of a feedback resistor (R) of the signal reading system.  Apparatus according to claim 8, characterized in that the gain control means changes the value of a dividing resistor for dividing the output electrical power of the signal reading system.  11. Apparatus according to claim 1, characterized in that the processing means comprise error correction means and in that the control means modify a redundancy of said error correction means.  12. Optical information storage apparatus, characterized in that it comprises means (81) for detecting a type of optical recording medium (93) of information, driving means (83, 93) for rotating or moving the recording medium for performing a process of recording or reproducing or erasing information on said recording medium, and control means (82) for adjusting the recording speed of the recording medium. rotating or moving the drive means according to an output signal of said type detecting means.  13. Apparatus according to claim 12, characterized in that it further comprises means (85) for projecting a light beam to record or reproduce the information on said recording medium, the control means modifying the energies of the light beams per unit of time and per unit area depending on the type of recording medium.  14. Apparatus for optical information storage, characterized in that it comprises processing means for performing a recording or reproducing or erasing process on an optical recording medium (131), means ( 134) for detecting the size of the recording medium, and means (135) for controlling the processing parameters used by the processing means in response to an output signal of the size detecting means.  15. Apparatus according to claim 14, characterized in that the control means comprise means for adjusting the amount of light projected onto the recording medium.  Apparatus according to claim 14, characterized in that the processing means comprise a focus control and tracking circuit (144), and that the control means comprises gain control means for controlling the gain of the focus control and tracking circuit.  17. Apparatus according to claim 14, characterized in that the control means regulate the information transfer rate in said processing means.  18. An optical information storage device, characterized in that it comprises first processing means (152) intended to execute a recording or reproduction or erasure processing on a first surface of a support of optical recording (131) of information, and second processing means (153) for performing a recording or reproducing or erasing process on a second surface of the recording medium.  19. Apparatus according to claim 18, characterized in that the first surface is constituted by a recordable medium (DRXW) and the second surface by an erasable medium (E-DRAW).  20; An apparatus according to claim 18, characterized in that it further comprises type identification means for detecting a type of recording medium and control means for setting control parameters of the first and second means of recording. processing in response to an output signal of the type identification means.  Apparatus according to claim 19, characterized in that the second surface is used as a working memory area or as a temporary storage area, and the first area is used for storage of the result of archiving said area.  22. Apparatus according to claim 18, characterized in that the first surface is constituted by a support (rem) used only for reproduction and the second surface is constituted by an erasable support (E-DRAW).  Apparatus according to claim 18, characterized in that the types of supports of the first and second surfaces differ.