Reproducing apparatus for a disc

Abstract: A reproducing apparatus for a disc in which data recorded on an optical disc (1) are read out by an optical pickup (7) and reproduced is disclosed. Before start of reproduction, it is determined if the disc (1) loaded into the apparatus is a data disc on which information data such as letter or character data or picture data are recorded, or an audio disc on which audio signals are recorded, and the playback mode is automatically selected as a function of the type of the optical disc (1) loaded into the apparatus. At the start time of the reproducing operation from the disc (1), the type discriminating data recorded on the disc (1) are read out and, as a function of the contents of the type discriminating data, switching is made automatically between the data reproducing operation and the audio signal reproducing operation, while the type of the optical disc (1) is displayed (27) on the display section (51, 54) on the basis of the type discriminating data.

Description: BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a reproducing apparatus for a disc in which optical discs having different information data recorded thereon, such as a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data, are recorded, or an audio disc on which audio signals are recorded may be reproduced selectively. More particularly, it relates to a reproducing apparatus for a disc in which it is determined if the optical disc loaded in the reproducing apparatus is a data disc or an audio disc and in which the reproducing operation may be switched automatically between the data disc reproducing operation and the audio disc reproducing operation depending on the tape of the loaded optical disc. Description of the Prior Art Among the discs on which information data are pre-recorded, there are a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data are recorded, and an audio disc, on which audio signals are recorded. There is proposed a reproducing apparatus for a disc which enables reproduction of an optical disc which may be a data disc or an audio disc. For reproducing a data disc by such reproducing system for a disc, the letter or character data or the picture data recorded on the data disc are read out by an optical pickup and the read-out data are displayed as visual data on the display by way of performing a data reproducing operation. for reproducing an audio disc on which audio signals are recorded, the audio signals recorded on the audio disc are read out an optical pickup and the read-out signal data are outputted as audio signals driving a speaker by means of an audio processing circuit by way of performing an audio signal reproducing operation. In this manner, the reproducing operation for information signals recorded on the optical disc differs as a function of whether the disc is a data disc or an audio disc. Therefore, when reproducing the optical disc with the use of the above mentioned reproducing apparatus for a disc, it is grasped in advance whether the optical disc loaded in the system is the data disc or the audio disc and the operating mode is set as a function of the disc type before proceeding to reproduction. With such reproducing system for a disc, since the reproducing mode is selected as a function of the optical disc to be loaded, that is, as a function of whether the disc is the data disc or the audio disc, should a mistake be made in the selection of the reproducing mode, it becomes impossible to reproduce data from the disc loaded in the system. For example, when the operating mode is set to the audio disc reproducing operation, and the data disc is loaded by mistake, the data signals read from the optical disc are reproduced as though they were musical sound signals, so that, in a majority of cases, only the voice as the noise is reproduced. As a matter of course, the letter or character data recorded on the data disc cannot be displayed as visible data. Conversely, when the operating mode is set to the data disc reproducing operation, and the audio disc is loaded by mistake, the information data such as letter or character data or picture data to be recorded on the data disc or the processing data for these information data cannot be read, so that the operation of reproducing the data read out by the optical pickup cannot be performed. For example, the operation of reproducing the data read out from the optical disc cannot be performed in succession to the data read-out operation. Should the user become aware of the error in loading the disc or in the setting of the operating mode and exchange the disc or the mode setting, it becomes possible to reproduce the desired optical disc. However, should the user not become aware of the error in loading the disc or in the setting of the operating mode, it may occur that the error be mistaken for a trouble in the disc reproducing system. There is also an inconvenience that a laborsome operation is necessitated for exchanging the disc or re-setting the operating node. EP-A-0 270 215 discloses a reproducing apparatus and method for both CD and complex disks capable of displaying a still frame of video information during the reproduction of the audio portion of a complex disk. When reproduction of a disk is first started, it is detected whether the disk is a complex disk or a CD. In the former case, the pickup is immediately shifted to the region where both audio and video information are recorded and reproduction is begun. During the reproduction of this region, a frame of video data is extracted and saved in a memory for reproduction during the playing of the soley audio portion of the disk. Furthermore, EP-A-0 081 958 discloses a tape recorder, including a cathode ray tube for selectively displaying signal parameters relating to the channels of the recorder. It can display information in a variety of different formats or "pages", any one of which may be selected by means of push buttons. In one page, the CRT provides alphanumeric identification of a variety of different signal parameters such as "bias", "input level", "output level", and others. By means of a rotary control, an operator can move a cursor on the screen to any particular one of these parameters, and a further rotary control is then used to select a particular one of the channels, whose identify is the displayed on the screen. By means of a rotary control, the operator can then adjust the value of the selected parameter in the selected channel, and a bar graph on the screen displays the parameter. OBJECT AND SUMMARY OF THE INVENTION It is an object of the present invention to provide a reproducing apparatus for a disc for reading out data recorded on an optical disc by an optical pickup and reproducing the read-out data, in which, before starting the reproduction, it is determined if the loaded disc is the data disc or the audio disc and the reproducing mode is selected automatically as a function of the type of the disc loaded in the apparatus, that is as a function of whether the disc is a disc for letter or character data or a disc for audio signals. It is another object of the present invention to provide a reproducing apparatus for a disc in which, when starting the reproducing operation, the type discriminating data recorded on the disc are read out, the reproducing operation is automatically switched between the data reproducing operation and the audio signal reproducing operation as a function of the type discriminating data, the disc type is displayed on the display section on the basis of the type discrimination data, the optical pickup is moved to a data record start portion on the disc when the type discriminating data indicate that the disc is the data disc, and the total record time as well as the number of airs are displayed on the display section when the type discriminating data indicates that the disc is the audio data, at the same time that the corresponding display is made on the display section. It is a further object of the present invention to provide a reproducing apparatus in which the type discriminating data recorded on the disc are read on starting the disc reproducing operation and switching is made between the first and the second operating sections associated with the reproducing operations for these discs as a function of the contents of the type discriminating data. These objects are achieved by the invention as defined in the appended claims. The above and other objects as well as the advantages of the present invention will become apparent from the following description especially when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block view showing a reproducing apparatus for a disc according to the present invention. Fig. 2 is a diagrammatic view showing the format of a subcoding of an optical disc loaded in the reproducing apparatus for a disc according to the present invention. Fig. 3 is a diagrammatic view showing the format of the Q-channel in the sub-coding of the optical disc. Fig. 4 is a diagrammatic view showing the format of the contents of the data recorded on the optical disc. Fig. 5 is a diagrammatic view showing the format of a point recorded on the optical disc. Fig. 6 is a perspective view of a reproducing apparatus according to the present invention, with the lid opened and with the cartridge holder having been rotated to the disc cartridge inserting and detaching position. Fig. 7 is a side elevational view showing the reproducing apparatus for a disc. Fig. 8 is a plan view of the reproducing apparatus showing the display section and the key operating section with the lid opened. Fig. 9 is a perspective view showing the reproducing apparatus for a disc with a battery box attached thereto. Fig. 10 is a flowchart for illustrating the operation of the reproducing apparatus for a disc according to the present invention. Figs. 11 to 13 illustrate the display states in the display section. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The reproducing apparatus for a disc according to the present invention is adapted for selectively reading out and reproducing a data disc on which information data including letter or character data such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data, are recorded, or an audio disc, on which audio signals are recorded. The reproducing apparatus for a disc is constructed as shown in Fig. 1, and is formed by a reproducing system 2 for reproducing data recorded on an optical disc 1, a voice signal processing system 3 for voice signal processing of the read-out data, and a data processing system 4 for retrieving the read-out data for image display. These systems 2 to 4 are controlled by a central processing unit (CPU) 5 which will be elucidated subsequently. As CPU 5, a CPU manufactured by NEC Corporation under trade name of µPD7008 may preferably be employed. In the reproducing system 2, the CPU 5 is responsive to the input from a keyboard 31 to control a laser light source driving circuit 10, a thread feed motor 11, a biaxial actuator driving circuit 12 and a motor driving circuit 13. As the motor driving circuit 13, a device manufactured by Motorola Inc. under the trade name of MPC1715FU may preferably be employed. The CPU 5 control the motor driving circuit 13 for rotationally driving a spindle motor 6 at, for example, a constant linear velocity (CLV) or at a constant angular velocity (CAV), while simultaneously controlling the thread feed motor 11 actuating an optical pickup 7 comprised of an objective lens 14 constituting a biaxial device, a light source, a photodetector, a cylindrical lens or the like, for roughly shifting the light spot of a laser beam to a predetermined track on the optical disc 1. The CPU also controls the biaxial actuator driving circuit 12 to shift the object lens 14 of the pickup 7 both in the direction along the optical axis of lens for focusing control and in the direction normal to the optical axis to shift the beam spot into register with the predetermined track on the optical disc 1 for tracking control by way of reproducing the data recorded on the optical disc 1. With the optical disc 1, data are recorded on recording tracks formed by spirally or concentrically extending pregrooves or lands delimited between the adjoining pregrooves. On these recording tracks, frame sync signals, timing data, position data and data per se are recorded alternately in the track direction in accordance with, for example, the so-called CD (compact disc) format. More specifically, each frame is constituted by frame sync signals of a pattern of two successive series of 11T transition intervals (out-of-rule pattern) which violates the modulation rule of the so-called eight-to-fourteen modulation (EFM), with T being a channel clock period in the CD format, followed by subcoding data as the timing or position data, including parity data. The subcoding data also include out-of-rule patterns S 0 and S 1 whereby the leading end of a block can be discriminated. The subcoding data are constituted by 98 blocks, inclusive of 2 blocks of the out-of-rule patterns S 0 and S 1 . The format for this subcoding is shown in Fig. 2. Fig. 2 shows a block consisting of 96 bytes, with the patterns S 0 , S 1 of the sync signals placed at the leading end, as described previously. Of these, P 1 to P 96 are used for accessing. The channel P simply indicates by "1" the region between data to be recorded, and is used for rough locating. The channel Q allows for finer control. It is this channel Q which is mainly used for accessing to an arbitrary track. Fig. 3 shows a format for bits Q 1 to Q 96 . In this figure, 4 "control" bits are used for identification of the numbers of audio channels, emphasis and digital data (CD-ROM). Thus the bits 0000 indicate 2-channel audio without preemphasis; the bits 1000 indicate 4-channel audio without preemphasis; the bits 0001 indicate 2-channel indicate 2-channel audio with preemphasis; the bits 1001 indicate 4-channel audio with preemphasis; and the bits 0100 indicate a data track. The 4 channels are currently not in use. The CD-ROM is denoted by bits 01*1, wherein * may be 0 or 1. The CD-ROM means an optical disc on which there are recorded letter or character data, such as Japanese dictionary data, english-Japanese dictionary data or encyclopedia data. In accordance with the above format, a directory called the table of contents or TOC data are recorded in a lead-in region on the inner periphery of the disc. In general, the TOC data are read before reproduction to grasp the position information, the timing information, or the like recorded on the disc, to facilitate accessing to an arbitrary track. The TOC data format is comprised of 72 bit data shown in Fig. 3, which are allotted to musical movement number, point, elapsed time in a musical movement (minutes, seconds and frame numbers), the absolute time of the contents of the point (minutes, seconds and frame numbers). The points and the contents of the points are as shown in Fig. 5. The absolute time at which each musical movement indicated by the numbers with points 00 to 97 (Fig. 5). When POINT is A0, PMIN indicates the number of the first musical movement. PSEC = PFRAME = 0 When POINT is A1, PMIN indicates the number of the last musical movement. PSEC = PFRAME = 0 When POINT is A2, PMIN, PSEC and PFRAME indicate the absolute time when readout is started. These contents are recorded three times each in the lead-in region. The TOC data read out from the lead-in region before reproduction are supplied to error detection-data detection circuit 8 shown in Fig. 1. As the error detection-data detection circuit 8, a device manufactured by Sony Corporation under the trade name of CXA1082BQ is preferably employed. This error detection-data detection circuit 8 also detects a laser output error, a focusing error or a tracking error, in addition to the TOC error, and transmits the laser output error signal to laser light source driving circuit 10, while transmitting the focusing error signal and the tracking error signal to biaxial actuator driving circuit 12. The laser light source driving circuit 10 performs a control operation by the laser output error signal so that the power of the laser light irradiated on the surface of the disc 1 will be constant, whereas the biaxial actuator driving circuit 12 performs a control operation in such a manner that the object lens 14 is driven and displaced responsive to the focusing error signal and the tracking error signal to maintain focusing and tracking in the normal state to provide for accurate data readout. On the other hand, the TOC data reproduced from the optical disc 1 are supplied via error detection-data detection circuit 8 to CD signal processing circuit 15 of the signal processing system 3. As the CD signal processing circuit 15, a device manufactured by Sony Corporation under the trade name of CXD1135Q is preferably employed. The software program or the like is recorded in ROM 22 and RAM 23 and, on the basis of the data read out in accordance with the program, the CPU 5 discriminates the type of the loaded disc to transmit the discrimination data to the CD signal processing circuit 15. The circuit 15 is responsive to the discrimination data supplied thereto to switch the signal processing systems. That is, when the discrimination data that the loaded disc is the audio disc is supplied to the CD signal processing circuit 15, the circuit 15 transmits the voice data signals supplied thereto to D/A converter 16. As this D/A converter, a device manufactured by Sony Corporation under the trade name of CXD1161M. this D/A converter 16 converts the voice data signal supplied thereto into signals, which are supplied to audio reproducing circuit 17 so as to be converted into voice signals, which are transmitted at output terminal 18. As the audio reproducing circuit 17, a device manufactured by Mitsubishi Electric Corporation under the trade name of M51568 is preferably employed. On the other hand, when the discrimination data that the loaded disc is the data disc, that is, the CD-ROM, is supplied to the CD signal processing circuit 15, the circuit 15 transmits character signals or the like supplied thereto to a CD-ROM signal processing circuit 19. As this CD-ROM signal processing circuit 19, a device manufactured by Sanyo Electric Co., Ltd. under the trade name of LC8951, is preferably employed. The character data signals supplied to the CD-ROM signal processing circuit 19 are read out responsive to signals supplied from CPU 5 via random access memory (RAM) 20 functioning as a transient storage memory. As the RAM 20, a device manufactured by Sony Corporation under the trade name of CXK5864 is preferably employed. The ROM 22 and the RAM 23, on which the program or the like is recorded, are connected to data bus 21. As the ROM 22, a device manufactured by NEC Corporation under the trade name of µPD23C100 is preferably employed and, as the RAM 23, a device manufactured by NEC Corporation under the trade name of µPD43256 is preferably employed. The read out signals, such as the character data, are transmitted over data bus 21. A display image is recorded and formed in video RAM 26 by a Kanji pattern or the like read out from Kanji ROM 24 in accordance with the character data signals. The display image in the video RAM 26 is read out by display controller 25 responsive to signals from CPU 5 so as to be displayed in a display section 27 such as a liquid crystal display (LCD) plate. As the Kanji ROM 24, a device manufactured by NEC Corporation under the trade name of µPD23C2000 is preferably employed. As the display controller 25, a device manufactured by Seiko Epson Inc. under the trade name of SED1330 is preferably employed and, as the video RAM 26, a device manufactured by NEC Corporation under the trade name of µPD43256, is preferably employed. If an external interface is connected to a connector 28, a switch 29 is turned on to reset the CPU 5 as soon as the interface is in circuit so that signal processing is performed under the instructions from the interface. The instructions from the interface are processed by an external processing circuit 30 and the processed data are displayed on the display section 27 via data bus 21 as described in the foregoing. With the above described reproducing apparatus 40, the portions of the reproducing apparatus for a disc which are used as a man-machine interface for data processing and display are not in need of strict timing processing and hence may be processed as the main routine, while the remaining operation may be performed by an interrupt routine, so that the signal processing in its entirety may be taken charge of by the sole CPU 5. Also, in consideration that software control is performed between the driving CPU of the present apparatus and the host CPU of a commercially available microcomputer system provided outside the present apparatus, the code system between the command packet and the status is utilized in the bus line system interconnecting these CPU5. When the present apparatus is desired to be controlled from an external host, the main routine on the drive CPU side of the present system is replaced by HALT commands so that the present system may be used by the host CPU only by starting the bus line control routine. The above described reproducing apparatus, provided with the function of an electronic dictionary and audio signal reproduction, is constructed as a unit by the construction shown in Figs. 6, 7 and 8. Referring to Fig. 6, the reproducing apparatus includes a main body 44, in the form of a regular parallelepiped, within which are disposed a reproducing system 2 for reading and reproducing information signals recorded on an optical disc 1, such as a data disc and an audio disc shown in Fig. 1, a CPU 5, a voice signal processing system 3 and a data processing system 4 excluding the display section 27 constituted by a display element such as LCD. As shown in Fig. 6, the main body 44 is of a size that can be placed on the palm of a hand and has a disc loading section 45 on its upper surface into which may be loaded a disc cartridge accommodating an optical disc 1 about 8 cm in diameter. Thus the main body 44 has a width W about equal to 105 mm, a length L about equal to 135 mm and a height H equal to 45 mm. A disc rotating-driving device 47 including a disc table 46 rotationally driven by a spindle motor 6 constituting the reproducing system 2 is provided at the center of the disc loading section 45. An optical pickup 7 is movable mounted for scanning the signal recording area of the optical disc 1 mounted on the disc table 46. The disc rotating-driving device 47 and the optical pickup 7 are supported by a chassis base plate 47 covering the upper surface of the main body 44. On the disc loading section 45, there are provided positioning pins 48, 48 and height setting pins 49, 49 for setting the positions of the disc cartridge loaded in the disc loading section 45 in both the horizontal and vertical positions. On the main body 44, there is mounted a cartridge holder 50 for loading a disc cartridge to the disc loading section 45 by means of the chassis base plate 47. The cartridge holder 50 is supported by the chassis base plate 47 so as to be turned between a raised position laying the disc loading section 45 open to enable the disc cartridge to be introduced into the cartridge holder and a lower position covering the disc loading section 45. On the main body 44, there is also mounted a keyboard cover 51 which is turned to follow the rotation of the cartridge holder 50. That is, the keyboard cover 51 is rotatably supported between cover mounting sections 52, 53. When the cartridge holder 50 is turned to the raised position, the keyboard cover 51 is turned to the raised position, along with the cartridge holder 50, as shown in Fig. 6 and, when the cartridge holder 50 is turned to the lower position covering the disc loading section 45, the keyboard cover 51 is lowered to cover the disc loading section 45, as shown in Fig. 8. On the main body 44, a lid 54 covering the upper surface of the main body 44 and the keyboard cover 51 is rotatably mounted by a supporting shaft 55 mounted on cover mounting sections 52, 53. On the inner surface of the cover 47, that is on the surface of the lid 54 facing the upper surface of the keyboard cover 51 on closure of the main body 44, there is provided a display section 27 for displaying the information read out from the optical disc 1 as the visual information. The distal edge of the lid 54 is formed with a locking piece 57 engaging in a mating locking portion 56 provided in the main body 44 for locking the lid 54 in the closing position. On the forward lateral side of the main body 44, there are provided a playback key 58 for designating the reproduction of the audio disc loaded in the disc reproducing apparatus, a fast feed key 59 for designating the forward fast feed, a reverse feed key 60 for designating the reverse fast feed and a power source switch or for on/off control of the power source of the apparatus. The playback key 58, fast feed key 59 and the reverse feed key 60 constitute a first operating section which comes into operation when the fast feed mode of the audio disc is selected. Meanwhile, on the upper surface of the keyboard cover 51, that is on the surface which is exposed to outside when the disc loading section 45 is covered by the keyboard cover 51, there are arrayed, as shown in Fig. 8, a plurality of alphabet keys 61, a cursor shift key 62 constituting a pointing device, a plurality of selection keys 63, 64 for selecting a selection item displayed on the display section 27 and designated by a cursor actuated by the cursor shift key 62, and a plurality of function selection keys 65. These keys provided on the upper surface of the keyboard cover 51 constitute a second operating section that comes into operation on selection of the playback mode of the data disc. The cursor shift key 62 constituting the positing device is provided with switches, not shown, in register with indices 62a, 62b, 62c and 62d provided on the surface of the key 62. On thrusting the indices 62a to 62d of the cursor shift key 62, the key 62 is turned in the vertical direction and in the left-and-right direction about the center of the key 62. The switches associated with the indices 62a to 62d of the cursor shift key 62 are operated by thrusting these indices 62a to 62d. By selective thrusting of these switches, the cursor displayed on the display section 27 is shifted so that the display information on the display section 27 as indicated by the cursor is variably designated by the cursor. On the back side of the main body 44, there is detachably mounted a rack of a chargeable battery 66 or a dry cell pack, as shown in Fig. 9. The operation of discriminating the loaded optical disc 1 in the reproducing apparatus of the present invention is explained with reference to a flowchart shown in Fig. 10. The reproducing apparatus performs an operation of discriminating the type of the loaded disc on the basis of the software program recorded in the ROM 22 and the RAM 23. The type of the disc in its entirety is determined in accordance with the TOC contents in the lower level of the software and, after accessing, the control field of the Q-channel data of the subcoding is used to generate an error code transmitting the contents of the decision to the upper level. In the upper layer level, the processing system for data processing, music reproduction or an upper level processing system are merged and a limited access demand is made to the lower level. The signal processing systems in the CD signal processing system are switched as a function of the contents of the returned error codes. Referring to Fig. 10, it is determined at step 101 if the disc playback key is turned on. If the result of decision is NO, the step 101 is repeated until the disc playback key is turned on. If the result of decision is YES, the program proceeds to step 102. At step 102, the control fields A0, A1 of the Q channel and the control fields of the track data indicated by A0 are read in response to the access request from the upper level of the software. If the read-out data is 00**, the disc is determined to be a disc for music (Fig. 5). If at least one of the read-out data is 01*1, the disc is determined to be a data disc, such as an encyclopedia or dictionary. The error code, which represents the contents of discrimination, is returned to the upper level of the software. The program then proceeds to step 103. At step 103, it is determined at the upper level if the disc is operatable. If the result of decision is YES, the program proceeds to step 104 where the display "Disc is not inserted" is made on the display section 27, as shown in Fig. 11 and the operation is terminated. If the result is NO, the program proceeds to step 105. At step 105, it is determined in the upper level if the disc discriminated at step 102 is the data disc. If the result of decision is NO, the program proceeds to step 109 where the display "This Disc is an Audio Disc" is made as shown in Fig. 13. If the result is YES, the program proceeds to step 106 where the display such as "this Disc is a Ko-ji-en" is made on the display section 27 as shown in Fig. 12 for displaying the name or title of the loaded disc. Simultaneously, the signal processing system of the CD signal processing circuit 15 is switched to the system for data disc, while an accessing is made to addresses 00', 02" 16 where the contents corresponding to TOC for data disc data are recorded and, after the data of the addresses are read, data retrieving is started. If the result of decision is NO, the program proceeds to step 107. At step 107, it is determined at the upper level if the load disc is the audio disc. If the result is NO, the program proceeds to step 108 where the display "Disc is not Inserted" is made on the display screen as shown in Fig. 11. If the result is YES, the program proceeds to 109 where the display concerning the total time and the number of airs is made besides the display "This Disc is an Audio Disc". Simultaneously, the audio processing of switching the signal processing system of the CD signal processing circuit 15 to the system for musical signals is mode to terminate the operation. From the foregoing it is seen that, by reading out the control fields of the control bits A0 and A1 of the Q channel of the TOC data and the control field of the track data indicated by the control bit A0, it may be discriminated if the loaded optical disc is the music disc or the data disc, and that, by automatically switching the signal processing systems responsive thereto, reproduction suited to the disc type may be made even if the user should have loaded the optical disc without being conscious about the type of the disc. Meanwhile, the above described reproducing apparatus may be usable when the disc loaded therein is of the small memory capacity with, for example, a 20-byte RAM and a 300-byte program, an optical disc conforming to the World Standard Format IS09600, or a music disc. The foregoing description has been made of the operation of the simple type discrimination of the disc type. In case of more intensive discrimination, the total contents of the TOC data are read out, it is sufficient if the total control fields are checked as described previously, the continuous regions are stored in the memory and the error code is produced when the region other than the stored region is designated by the type of access demand. In such case, it is necessary to procure the processing memory capacity of, for example, 600 bytes for RAM and the program of ca. 1.2 kilobytes. In case of performing the simple type processing and intensive processing, the access instructions are first executed, the control fields are checked for each minimum data unit and, if the data are such that cannot be executed by the current processing, the voice processing is muted and the error code reflecting the contents is generated to enable the above operation to be performed without noise generation.

Claims: A reproducing apparatus for a disc for reading out data recorded on an optical disc (1) by an optical pickup (7) for reproduction, comprising control means (3, 4) for reading out type discriminating data on the disc (1) at the time of starting disc data reproduction and automatically switching between a data reproducing operation and an audio signal reproducing operation, wherein said control means (3, 4) generates display (27) control signals indicating the type of the optical disc (1) on the basis of said type discrimination data, characterized in that when the type discrimination data indicate that the disc (1) is the optical data disc, said control means (3, 4) transmit said display control signal before moving said optical pickups (7) to a record start portion of the disc (1) and when said type discriminating data indicate that the disc (1) is an optical disc on which audio signals are recorded, said control means (3, 4) transmit a signal indicating the total recorded time and number of airs in addition to said display control signal. The reproducing apparatus according to claim 1, wherein said control means comprises discriminating means (8, 11, 12) for shifting said optical pickup (7) towards the innermost periphery of the disc (1) at the time of starting the reproduction operation to read out the type discrimination data recorded towards the innermost periphery of the disc (1) by said optical pickup (7) to discriminate the type of the optical disc (1) on the basis of said type discrimination data, and switching means (5, 15) for automatically switching between the data reproducing operation and the audio signal reproducing operation on the basis of the detection output from said discriminating means. A reproducing apparatus according to one of the preceeding claims wherein a display section (51, 54) has its display contents switched by said control means.

Inventors: MIURA YOSHIHIRO, TAKAGI KOJI, MIURA, YOSHIHIRO, TAKAGI, KOJI
Applicants: SONY CORP, SONY CORPORATION
Application year: 1990
Main classification: G11B7
IPC codes: G11B27, G11B7, G11B33, G11B19, G11B20