TW200307283A - Apparatus and method for measuring prepit waveform for optical recording medium - Google Patents

Abstract

An apparatus and a method for measuring a prepit waveform for an optical recording medium having a recording area on which prepits repeatedly formed between tracks. The apparatus receives reflected light of a laser beam irradiated on the optical recording medium so as to generate a push-pull signal, detects a synchronizing signal component corresponding to a synchronous prepit in the push-pull signal, and every time the synchronizing signal component is detected, extracts a signal component to be measured in the push-pull signal. The apparatus further inhibits the extraction of the signal component to be measured during a period which includes at least a track-jump period when the laser beam is track-jumped and a first predetermined period subsequent to the track-jump period.

Description

200307283 发明, description of the invention (the description of the invention should state: the technical field to which the invention belongs, the prior art, the content, the embodiments, and the drawings are briefly explained) C ^ ^ the technical field ^^ field] | Field of the invention The invention relates to an application An apparatus and method for measuring a preformed 5 pit waveform for an optical recording medium having a recording area on which a preformed pit is repeatedly formed between a track. BACKGROUND OF THE INVENTION Mizuki, optical discs such as CD-R, CD-RW, DVD-R, DVD-RW and 10 DVD-RAM are known as discs capable of writing information. In addition, a product of an information recording device such as a disc recorder is available, which allows a general user to record arbitrary information data on such a disc. FIG. 1 is a diagram schematically showing a region structure of a DVD-RW as a recording disc. 15 As shown in Figure 1, the DVD-RW has a data structure in which a PCA (power correction area), an RMA (record management area), a lead-in area, data, and a lead-out area are arranged on the slave disc From the inner edge side to the outer edge side. PC A is an area for performing a test write at a recording power% of a laser beam. A is an area for writing official information related to record 20. A raised area is formed in a part of the lead-in area. The raised area has a phase recess, which has been formed in advance on the guideway of the disc. Fig. 2 is a diagram showing a part of a recording surface of a recordable disc. 200307283 发明 Description of the invention As shown in FIG. 2, a convex groove 10 and an indentation groove 103 of an information pit Pt on which a information substrate should be formed are formed on a disc substrate 101 at intervals. The channels 102 are shaped so that they are formed spirally or collectively. Furthermore, a plurality of LPPs (pre-pit 5 pits) are formed between the adjacent groove tracks 103. LPPs 104 have been pre-formed on Ground Road 102 to know the recording timing and address when recording information on a disc recorder. Ground track 102, groove track 103, and LPPs 104 are seen from the disc substrate 101 side as land, groove, and pit, respectively. In a disc player for reproducing an optical disc with LPPs, 10 provides an LPP detection circuit. The LPP detection circuit is constructed by a binary circuit. A reflected light beam from an optical disc is received by a pickup, for example, by a two-point optical detector separated in a tangential direction of the road, so that the difference signal of the output signal of each tester is measured. That is, a radial push-pull signal PP. The push-pull signal pp has a waveform as shown in FIG. 3, and an LPP 15 component is a component reflected from the push-pull signal PP. Therefore, by comparing the size of the push-pull signal PP with a critical value, a pre-pit detection signal PPd representing the detection of LPP is generated. The pre-pit detection signal PPD causes a change in the size of the pulse shape as shown in Fig. 4 at each reading position of the pickup corresponding to the Lpp. 20 As shown in Fig. 4, one synchronization pulse PSYNC appears every period τ and exists in the pre-pit price measurement signal 1 >! ≫ 0. Although two pre-data pulses exist at a predetermined interval ± after the synchronization pulse Psync, they do not always exist at every cycle to represent data such as a bit address or the like. As shown in Figure 4, 200307283, which exists at the third position from the synchronous pulse beast. 玖, description of the invention A pulse is a pre-data pulse that contains information on a single address and status for recording? 0. When information is recorded on the optical disc, the address and condition of a writing strategy such as that on the optical disc are detected based on the pre-pit detection signal ppD, and then the information is recorded. 5 For a manufacturer of optical discs including LPPs, it is necessary that the LPPs of the manufactured optical discs meet the standards. In order to identify the disc as a standard optical disc, an AR (Aperture Ratio) measurement is performed. In the eight-measurement. C ^^ 内 内 j 10 Summary of the Invention In view of this, one object of the present invention is to provide a device and method for measuring a pre-pit shape which can accurately measure the waveform of a pre-pit. The narrow area of the convex area of the pit optical recording medium is necessary for calculating an AR value. 15 According to the present invention, there is provided a pre-pitted wave shape measuring device i for an optical recording medium, the optical recording medium having a recording area or on which repeatedly forming a track-related relationship between tracks. Information synchronous pre-pits and information pre-pits, the device includes: a light detection device having a photosensitive surface, which is divided into first and second photosensitive surfaces in the tangential direction 20 of the road, so that the first A first and second photosensitive surface for receiving a reflected light of laser light irradiated onto the recording surface, and used to generate first and first light detection signals corresponding to the photosensitive amounts of the first and second photosensitive surfaces, respectively; subtraction Device for calculating the difference between the first and second light detection signals generated by the light detection device to generate a push-pull message 200307283 200, invention description 10 = capture clothes, which is used to detect a Synchronous m copies of the push-pull signal corresponding to the synchronous pre-concavity, and used to capture each time a sync signal component is detected-the signal component to be measured in the push-pull signal, the signal component is detected from sync to sync. Signal There is a center in time when the time interval between the synchronous pre-pit and the information pre-pit starts at the beginning of the minute; the track jump split is used to form a position on which the laser beam performs: Irradiates into the recording area; and a prohibition control device for: firstly determining during the jump of the jump of the laser beam by the jump jump device and a first predetermined time after the jump jump; During the period, 'the capture device is prohibited from capturing the signal component to be measured. 15 According to the present invention, there is provided a pre-pit wave detection method for an optical recording medium having a recording area on which synchronized pre-pits are repeatedly formed between tracks and an information channel is displayed. Zhibei said the pre-pits, the method includes the following steps: by receiving a photosensitive surface in the tangential direction of the transportation ^ to divide the obtained first and second photosensitive surface to receive-to shoot to the recording surface The reflected light of the above laser beam and the first and first light detections corresponding to the photosensitivities of the first and second photosensitive surfaces are respectively calculated; the difference between the first and second optical debt measurement signals is calculated to generate A push-pull signal; detecting the sync flood component in the push-pull signal corresponding to the synchronous pre-pit; and each time the sync signal component is detected, it is used to capture the signal component to be measured in the push-pull signal, the signal The component has a center at the time when the time interval between the synchronous pre-pit and the information pre-pit starts from the time when the debt is measured to the synchronous signal component; forming a position 'on which a laser beam is formed The track jumps irradiated into the recording area; 20 200307283 玖, the description of the invention includes at least one track jump period during which the laser beam is tracked by the track jump device and a first predetermined period t after the track jump period. During this period, the capture device is prohibited from capturing the signal components to be measured. Brief description of the drawing 5 Figure 1 is a figure showing the layout structure of the area of the DVD-RW; Figure 2 is a figure showing the structure of the recording surface of the DVD-RW;

Figure 3 is a graph showing a waveform of a push-pull signal including a LPP component; Figure 4 is a graph showing a waveform of a pre-pit detection signal; 10 Figure 5 is a waveform showing a pre-pit Figure 6 is a block diagram of a device for measuring a pre-pit wave shape according to an embodiment of the present invention; Figure 7 is a block diagram showing a head amplifier 'a prefab included in the device of Figure 6 Block diagram of pit detection circuit and configuration 15 of an LPP interval detection circuit;

Figure 8 is a block diagram showing the schematic configuration of the oscilloscope in the device shown in Figure 6; Figures 9A to 9C show the waveforms on multiple parts of the lpp interval detection circuit; Fig. 10 is a flowchart showing the area judgment operation performed by the personal computer shown in Fig. 7; Fig. 11 is a flowchart showing the use of the personal computer shown in Fig. 7 Figures 12A to 12D show the device in Figure 7 at the time of orbital jump. Figure 10 200307283 玖, waveforms in various parts of the description of the invention; and Figures 13 A and 13B each display An example of a pre-pit wave shape shown in the wave filter is shown.

Embodiment C] I 5 Detailed Description of the Preferred Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 6 shows a pre-pit wave measuring device according to one of the present invention. In the pre-pit pit waveform measuring device, a read / write head 2 is provided, which can write Bezien to an optical disc (e.g. DVD-RW) 1 / & read information 1 from it as a Review goals. In the read / write head 2, a recording laser beam generating device (not shown) is installed, which is used to record information data to a write-once or rewrite-type optical disc, which has As shown in Figure 2, a recording surface, a reading laser beam generating device (not shown), which is used to read recorded information (including information data) from the optical disc 1; Detector (shown at 20 in Figure 7). It is not always necessary to separately provide a recording laser beam generating device and a reading laser beam generating device, but it is also possible to use a laser beam generating device which generates a laser beam for recording during recording, and When reading, a laser beam is generated for reading. -The captured laser beam generating device emits a reading laser beam onto an optical disc 丨 rotated by a single motor 9, thereby forming an information reading point on a recording surface. As shown in FIG. 7, the 4-spectrum photodetector 20 includes a photoelectric conversion device i, which has a direction perpendicular to the tangent line along the information recording road (Cao Road 103) of the optical disc 1J1 and crosses vertically. The tangent of the recording track 11 200307283 感光, four photosensitive surfaces 20 to 20d divided in the direction of the invention description line. Because of the information reading points of the four photosensitive surfaces 20a to 20d, the photoelectric conversion device receives the reflected light from the optical disc 1 to generate a signal, such as the photosensitive signals Ra to Rd. Converted into a telegraph signal to get 5 of. A motor servo control unit 4 generates a focus error signal, a tracking error signal, and a slider drive signal based on the photosensitive signal and Rd, respectively. The focus error signal is supplied to a focus actuator (not shown) installed in the read / write head 2. The focus actuator adjusts the focus of one of the information reading points based on the focus error signal. The tracking error signal is supplied to a tracking actuator (not shown) installed in the read / write head 2. The tracking driver adjusts the formation position of the information reading point in the radial direction of a disc based on the tracking error signal. A slider driving signal is supplied to a slider 10. The slider 1 〇 moves the read / write head 15 in a radial direction of the disc at a speed according to the slider drive signal. The motor servo control unit 4 is connected to a track jump pulse generating circuit 40. The track jump pulse generating circuit 40 generates a track jump pulse in response to a track jump command from a personal computer 62 which will be described later. In response to the jump pulse of the track, the read / write position of the read / write head 2 on the optical disc 1 20 is moved inward by one motion of the tracking motor servo system of the motor servo control unit 4. The photosensitive signals Ra to Rd are supplied to a head amplifier 25 having adders 21 to 23 and a subtractor 24. The adder 21 adds the photosensitive signals Ra and Rd. The adder 22 adds the photosensitive signal to Rc. That is, the adder 21 will receive the light-sensitive signals Ra and Rd obtained when the light-sensing surfaces 20a and 20d of the photodetector 20 receive reflected light at 4 minutes 12 200307283 (invention description) to generate an added light-sensitive signal Ra + d. The adder 22 will receive the light-sensitive signals Rb and Rc obtained when the light-sensing surfaces 20b and 20c of the 4-point photodetector 20 receive the reflected light to generate an added light-sensitive signal Rb + e. 5 The adder 23 adds the output signals Ra + d and Rb + C of the adders 21 and 22. The output δίΐ s of the addition β 2 3 is a signal which is taken as an RF signal, that is, an * -RF signal is supplied to an information data reproduction circuit 30. The information data reproduction circuit 30 binarizes the master signal, and then sequentially executes a demodulation procedure, an error correction procedure, and a variety of different information decoding procedures, thereby reproducing a record 10 recorded on the optical disc 1 The information information (video data, audio data, computer data) on it and generated. The subtracter 24 subtracts the output signal Ra + d of the adder 21 from the output signal Rb + C of the adder 22. The output signal of the subtractor 24 becomes a flood signal representing the frequency of the orbital swing of 103, and it is supplied to a shaft motor servo 15 device 26 of the shaft motor 9. The shaft motor servo device 26 rotates the shaft motor 9 so that the frequency obtained by the output signal of the subtractor 24 is equal to a frequency corresponding to a predetermined rotation speed. Since the construction of the shaft motor servo device 26 has been disclosed in Japanese Patent Application No. Hei-10-283638, the description thereof is omitted here. 20 Based on the output signals of the adders 21 and 22, a pre-pit detection unit 5 detects a land track (pre-pit track) formed on an optical disc as shown in FIG. 2 1 2 Precast pits (Lpps) on the ground, to detect a precast pit flood number? ? 0 is supplied to a recording processing circuit 7. The recording processing circuit 7 is based on the pre-pit detection signal ppD to identify 13 200307283 玖, invention description The capture / write head 2 is currently performing recording at the current point in time, that is, on the groove track 103- Position, and supplies a control signal to the motor feeding system unit 4 which is used to allow the read / write head 2 to jump from the recording position to a desired recording position. Furthermore, the recording processing circuit 57 performs a desired recording modulation procedure on the information data to be recorded (information data for review), thereby generating a recording modulation data signal and supplying it to read / write Head 2. A recording laser beam generating device installed in the read / write head 2 generates a recording laser beam 'according to the recording and modulating data signals and emits it to the groove track 10 on the optical disc 1. . At this time, the heat 10 is transferred to an area where the laser beam irradiation is recorded on the groove track 103, and an information pit (mark) is formed in the area. Since the construction of one of the 3 recorded processing circuits 7 is also disclosed in Japanese Patent Application No. Hei-10-283638, further explanation is omitted here. As shown in Fig. 7, the pre-pit detection circuit 5 includes an amplifier 31 for amplifying the output signal Ra + d of the adder 21 by 15;-an amplifier 31 for amplifying the output signal Rb + c of the adder 22 Amplifier 32; a subtractor 33 for subtracting the output signal of the amplifier from the output signal of the amplifier 31 and producing a result as a radial push-pull signal (slot swing signal) pp; The output pusher-pull signal pp 20 of the subtractor 3 3 is binarized by a product boundary value TH, and a pre-pit detection signal PPD binarization circuit 34; an AND circuit 50; and a gate pulse generation Circuit 51. The gain G1 of the amplifier 31 and the gain G2 of the amplifier 32 are set to G1 = G2. The push-pull signal PP generated by the subtractor 33 is supplied to a [ρρ interval detection circuit 60 and an oscilloscope 61. One of the binarization circuits 34 outputs a signal 14 200307283 发明, description of the invention is supplied to the personal computer 62. The AND circuit 50 is connected to the gate pulse generating circuit 51 and the digitizing circuit 34 °. The gate pulse generating circuit 5 丨 generates a gate pulse in response to an AR measurement from a personal computer 62 to the raised area of the optical disc 1. period. 5 The AND circuit 50 stops supplying the pre-pit detection signal PPD from the binary circuit 34 to the personal computer 62 while the gate pulse is being generated. As shown in FIG. 7, the LPP interval detection circuit 60 includes a comparator 71, a 1/4 frequency division circuit 72, and a counter 73. The comparator 71 compares the push-pull signal PP with a wobble slice signal Wslice (reference size) to produce a binary wobble signal. The 1/4 frequency division circuit 72 divides the binary wobble signal to 1/4. The counter 73 counts the number of pulses of a clock signal to detect the period of the binary wobble signal. The frequency of the clock signal is sufficiently higher than the frequency of the push-pull signal. The count result of 73 is supplied to the personal computer 62 as an Lpp interval. 15 ^ When performing the AR measurement on the convex area of the optical disc 1, the personal computer 62 generates the above-mentioned track jump instruction to the track jump pulse generating circuit 40. During the AR measurement, a jump instruction is repeatedly generated in synchronization with the rotation of the shaft motor 9 to repeatedly play a track in a raised area of the optical disc. The oscilloscope 61 samples the push-pull signal pp and displays, for example, a portion corresponding to the LPP in the push-pull signal PP. A circle computer (hereinafter, a PC) 62 is connected to the oscilloscope 61. The PC 62 detects the size of the push-pull signal 卯 in the internal memory (such as a sampling memory 93, which will be described later) stored in an oscilloscope 61 and is detected by the LPP interval detection circuit 60. iLpp interval detection value 15 200307283 玖, description of the invention to calculate a delay time, J: Jiang Yu π ^, / ,,; described below. Although one of the specific constructions of pc 62 is not shown here, the complex / includes at least a CPU and an internal memory. The connection between the PC 62 and the leather 61 is based on interface standards such as GPIB, Win SE-T, and RS_232C. The signal (pre-pit detection signal PPD) generated by the 7L circuit 34 is supplied to an error detection circuit (not shown), which depends on the error rate of the supplied signal. 15 For example, the oscilloscope 61 may have a structure shown in FIG. That is, the oscilloscope 61 includes: -A / D converter 91; a control circuit%; sampling memory 93, a display memory 94; a χ driver%; a γ driver 96;-a display panel 97; an operation unit 98; and an interface 99. The A / D converter 91 converts an input analog signal into a digital signal. The control circuit 92 then writes the sampling data of the digital signal obtained by the A / D converter 91 into the sampling memory 93, reads the data to be displayed from the sampling memory 93, and writes it into the display memory 94. And form it. The display memory 94 has a storage position corresponding to each pixel of the display panel 97. The X and Y drivers 95 and 96 drive the display panel 97 based on the data written in the display memory 94, and cause the waveform of the input analog signal to be displayed on the display panel 97. The interface 99 is a circuit for connecting to the PC 62, which is based on interface standards such as GPIB, 10BASE-T, and RS-232C, and transfers the data written in the sampling memory 93 through the control circuit 92 to PC 62. The interface 99 relays a command from the PC 62 to the control circuit 92 ° 16 20 200307283 玖, description of the invention In the pre-pit pit waveform measuring device with the above structure, the push-pull signal pp generated by subtraction 33 has a similar The waveform of the sine waveform (although it is correctly said to be a waveform very similar to the sine waveform, but it is referred to as a sine waveform for ease of explanation), as shown in Figure 9A by the groove track 1 〇3, It oscillates as shown in the second figure in the case of the optical disc 1. As shown in Section 9A, the part corresponding to the LPPs in the push-pull signal PP, that is, most of the LPP components are projected from the sine waveform to the negative end and exceed the critical value. The two] LPp components not shown in Figure 9A correspond to Lpps for synchronization and the third LPP comes from Lpps for synchronization. That is, they have the waveform of the push-pull signal PP in the case where only a period part without 10 second 忡 is read out. In the comparator 7 丨 of the LPP interval detection circuit 60, the push-pull signal pp is compared with the wobble cut signal Wslice, and it becomes a waveform of a binary wobble signal, as shown in FIG. 9B. The binary wobble signal becomes a pulse signal 'If the size of the push-pull signal pp is higher than the size of the wobble-cut signal Wslice, 15 indicates "1", and if the size of the push-pull signal PP is lower than the size of the wobble-cut signal Wshce, then It states "0". The binary wobble signal is divided into 1/4 by the 1/4 divider circuit 72, so that it has a waveform as shown in Figure 9C. The period of the 1/4 divide signal is t Length equal to twice the time from the LPp component for synchronization to the third LPP component of the push-pull signal PP. Because the 20-axis motor 9 uses the motor servo operation performed by the axis motor servo device to convert the optical disc 1 It rotates at a predetermined linear speed, so it is assumed that the period t associated with the optical disc 1 is fixed. The period t of the quarter-divided signal is measured by counting the number of pulses of the clock signal with the counter 73. Counter The count value of 73, that is, the period t is supplied 17 200307283 玖, the invention description is provided to the PC 62. The PC 62 calculates t / 2 by using the count value t of the counter 73, thereby obtaining the LPP component used for synchronization to push and pull Time required for the third LPP component of the signal PP The calculated t / 2 value is used as a delay time is generally supplied to the oscilloscope 61. 5 t during the calculation / operation of the delay time 2, PC 62 detect the push-pull signal

Location of PP's LPP components for synchronization. Each time the LPP component is detected by comparing the push-pull signal PP with the threshold value TH, the position of the LPP component used for synchronization is determined from the generation interval of the LPP component. As the time obtained as an interval between the LPP components, there is a time from the LPP component (10 first LPP component) used for synchronization to the second LPP component, and a time from the second LPP component to the third LPP component, A time from the LPP component used for synchronization to the third LPP component, a time from the second LPP component to the next cycle for the LPP component, a time from the third LPP component to the next cycle for the synchronization The time of the LPP component, and the time from the LPP component used for synchronization to the LPP component used for synchronization in the next 15 cycles. Although the time from the LPP component used for synchronization to the second LPP component and the time from the second LPP component to the third LPP component are equal and the shortest, the other times are long in order, as shown above. However, as compared with the time from the LPP component used for synchronization to the second LPP component, the time from the second LPP component to the third LPP component is 20 minutes, and the time from the LPP component used for synchronization to the third LPP component Time, the time from the second LPP component to the LPP component for synchronization in the next cycle, the time from the third LPP component to the LPP component for synchronization in the next cycle, and the time from the synchronized LPP component to the next cycle The time to synchronize the LPP components is sufficiently long. If no LpP component is detected at the point in time when a predetermined time TA has elapsed since the detection of an LPP component 18 200307283 玖, the description of the invention, the LPP component subsequently created is the LPP component for synchronization. For example, the predetermined time TA is set to be slightly longer than the time t / 2. The PC 62 generates a trigger signal of the oscilloscope 61. The trigger signal is an external 5 synchronization signal, which shows the reference of the time base used in the oscilloscope 61. When the PC 62 generates a trigger signal, as shown in No. 10, the PC 62 first determines whether the convexity of the optical disc 1 is determined. The AR area performs AR measurement (step si). If the AR measurement is performed on the convex area of the optical disc 1, a gate pulse command and a track jump command are generated in synchronization with the 10-force rotation of the pumping motor 9. If an AR measurement is performed on a non-convex region, a gate pulse command and a track jump command are not generated (step S3). If an AR measurement is performed on a non-convex region, a gate pulse and a track jump pulse are not generated. In this way, the pre-pit detection signal PPD outputted from the digitizing circuit 34 is directly supplied to the pC 62 through the AND circuit 52. On the other hand, if an Ar measurement is performed on a convex area of the optical disc, a gate pulse is generated from the gate pulse generating circuit 51 in response to a pulse command from the PC 62. When a gate pulse is generated, the pre-pit detection signal ppD output from the digitizing circuit 34 is stopped by the AND circuit 50, and it is not supplied to the 20 pc 62. The track jump pulse generating circuit generates a track jump pulse in response to a track jump command from the PC 62. By generating a track jump pulse, one of the raised areas in the optical disc 1 is repeatedly played. There is not only one type of optical disc with a raised area that cannot be read at all (for example, a DVD_RW version 丨 .0), but there are others with a package 19 200307283 玖, the description of the invention includes sequentially from the inside of the disc Point out one readable part and one non-readable part of the damaged convex area of the optical disc (for example, a DVD_RW version ⑶. According to DVD-RW version 1.1, 176 control data blocks located in the convex area (Referred to as a control data area) belongs to a readable part, and the subsequent 5 16 motor servo blocks belong to an unreadable part. Furthermore, according to DVD RW version 1.1, it is necessary to prevent copying Information and the like are recorded in readable deep phase pits in the readable portion, in which most discs have no LPP formed between the tracks. In order to prevent the information overwritten in the area from being read, Shallow phase pits are formed in the unreadable portion, similar to the data area 10, in which LPPs are formed between the tracks. Lpps are provided in the unreadable portion, so that an optical beam can be accessed just to access Data area behind unreadable part In this way, when the optical disc includes such a readable portion and an unfeedable wound, an AR measurement should be performed on the unreadable portion in the raised area. In this case, the PC 62 monitoring is performed as described in Section 11 The output signal of the circuit 50 shown in the figure, and whether the pre-pit detection signal PPD as the _Lpp component has been generated (step S11), as shown in Figure 10. If the pre-pit is generated The pit detection signal PPD starts time measurement from this point of time (step S12). It is discriminated whether the measured time has exceeded a predetermined time (step 20S13). If the measured time does not exceed a predetermined time At time TA, the processing routine returns to step S11, and discriminates whether a new pre-pit detection signal PPD has been generated. If it is determined in step s 11 that the pre-pit detection signal PPD has not been generated, then step S13 is performed. If it is judged in step S13 that the measured time has exceeded a predetermined value of 20 200307283 玖, invention description time TA, it is repeatedly discriminated whether a pre-pit detection signal PPD has been generated (step S14). If it is judged in step S14 that Produce prefab The pit detection signal PPD discriminates whether a gate pulse is generated (step S15). As described above, when performing the AR measurement of the raised area, a gate pulse is generated from the gate pulse generating circuit 51 to respond to the signal from the PC 62. Gate pulse command. The gate pulse is generated slightly earlier than the track jump pulse (Figure 12A), as shown in Figure 12B. The time difference between the edge before the gate pulse and the edge before the track jump pulse corresponds to the first LPP Time between the third LPP and 1/2 ⑤ When performing AR measurement of the raised area, repeatedly search (play) the same single track within the raised 10 area. In this way, when performing a track jump, a tracking The error signal has s characteristics as shown in Fig. 12C, so that the reading position of the read / write head 2 to the optical disc 丨 is moved back to one track in a substantially radial direction. After the track jump pulse is generated, a gate pulse is generated until the tracking error signal almost returns to a reference size, that is, until a 15 track jump is completed. In step S15, if it is determined that the gate pulse is generated, the measured time is reset to the initial value (step S16), and the program returns to step su. In step S15, if it is judged that no gate rush is generated, the program returns to step S14. 〇20 In step S14, if it is judged that a “pre-pit ㈣ signal PPD 'is generated, a trigger signal is supplied from the PC 62 to the oscilloscope. 61 (step S17). The pre-coat detection signal corresponds to the composition of the synchronous Lpp. In response to the trigger signal, and only once from the reference time point

The oscilloscope 61 displays the waveform of the pre-pits so that its time point is used as a reference. 21 200307283 玖, the invention explains that the point at the delay time t / 2 is located at the center of the display. The display operation will be described by using the configuration of the oscilloscope 61 shown in FIG. When receiving the trigger signal from the PC 62 through the interface 99, the control circuit 92 sequentially writes the sampling data of the digital signal obtained by the a / D converter 91 into the sampling memory 93 5. It is sufficient to execute the above operation for a set time from the trigger signal and repeat it. The data to be displayed is read out from the sampling memory 93 and written into the display memory 94 and formed. The reading operation is performed in such a manner that the data on the point tc, which has passed only the delay time [/ 2] from the point of time when the supply fl is triggered, is displayed on the center of the display panel 97. That is, at each trigger signal, only the sampled data corresponding to the time width Tc of the time point Tc τΔΔί is repeatedly read and written into the display memory 94. It is assumed that the number of scales of the time base of the display panel 97 is set to 2η (η is an integer), and the unit time per scale is set to 仏. Since each sampled data formed in the display memory 94 is displayed on the display panel 97 by the χ * γ drivers% 15 and 96, the pre-pitted waveform is displayed on the center of the display panel 97. 20

When performing the AR measurement on the raised area of the optical disc 1, the pre-pit detection Λ number PPD is not output from the αν〇 circuit 50 during the gate pulse generation as shown in Section 12B. In this way, during the interpulse period ^, no trigger Λ number is generated, and after the gate pulse generation is stopped, no trigger signal is generated, until the first time the pre-pit detection signal is output from the AND circuit 5 () at least, widely. Until the scheduled time TA. Even if the push-pull signal pp is distorted during one track and jumping period, as shown in Figure 12d, the distorted signal has not been added to the overlapped waveform (pre-pitted waveform) of the push-pull signal PP, and its combination 22 200307283 玖, The invention describes non-display noise such as in overlapping waveforms. Fig. 13A shows an example in which a pre-pit waveform including a pre-pit detection signal PPD during a track jump during an AR measurement of a raised area is displayed on the display panel 97. In the waveform shown in FIG. 13A, when an orbit jump is performed, it is judged that the LPP part of a non-push-pull signal PP is an LPP, thereby triggering at the time of asynchronous [ρρ]. As a result, the component having the magnitude of deviation of the non-push-pull signal PP: Lpp becomes noise in the pre-pit waveform. FIG. 3B shows other examples. As mentioned above, the pre-pit waveforms of the components of the pre-pit detection signal No. 10 PPD that are not included in each track jump period are displayed on the display panel 97. In the waveform shown in Figure 13B, the deviation of the push-pull signal PP caused by the orbital jump did not cause the time trigger of the asynchronous Lpp, and the noise included in the waveform shown in Figure 13A can be removed.讯 components. Therefore, it is possible to obtain 15 preformed pit waveforms from which the noise component on the dominating jump is removed as data. If in PC 62, the AR value for a raised area is automatically calculated based on the pre-pit wave shape, the maximum APmax and minimum APmin without noise components can be obtained, and then the AR value can be calculated correctly . The LPP interval detection circuit 60 is not limited to the above-mentioned configuration. Use Example 20 The j ^ pp interval detection circuit of other configuration as shown in 2001-308868 is possible. The embodiment deals with raised areas, but the present invention can also be applied to a narrow area on an optical recording medium on which a pre-pit wave shape is recorded. Although the above embodiment is described with reference to the raised area, the present invention can be applied not only to the raised area 23 200307283, the invention description, but also to Gan, A1 J, which is one of the pre-pitted waveforms. Narrow area on an optical recording medium. Although the above embodiments are described as an optical disc as an optical recording medium, the present invention can also be applied to other optical media such as an optical card having multiple tracks. As described above, the present invention can eliminate the noise component to measure a pre-pit wave in a narrow area such as a raised region of an optical disc with a pre-pit. [Schematic description] ίο Figure 1 is a display DVD_RW The figure of the layout structure of the area; Figure 2 is a figure showing the structure of the recording surface of DVD_RW; Figure 3 is a figure showing the waveform of a push-pull signal including the LPP component; Figure 4 is a display Figure 5 of the waveform of a pre-pit detection signal; Figure 5 is a figure showing a waveform of a pre-pit; Figure 6 is a block of a device for measuring a waveform of a pre-pit according to an embodiment of the present invention Fig. 7 is a block diagram showing a configuration 20 of a head amplifier included in the device of Fig. 6, a pre-pit detection circuit, and an LPP interval detection circuit; Fig. 8 is a display Block diagram of the sound configuration of the oscilloscope in the device shown in Figure 6; Figures 9A to 9C show the waveforms on multiple parts of the LPP interval detection circuit; 24 200307283 Figure 10 is a flowchart of its The area judgment operation performed by the personal computer shown in FIG. 7 is shown; FIG. 11 is a flowchart showing the operation performed by the personal computer shown in FIG. 7 to generate a trigger signal; Figures 12A to 12D show the waveforms on various parts of the device in Figure 7 at orbital jump times; and

Figures 13 A and 13 B each show an example of one of the pre-pit waveforms shown in the oscilloscope. [Representative symbol table of main components of the drawing] [...] Optical disc 2 ... [Read / write head 4] [...] Motor servo control unit 5. [...] Pre-pit detection circuit 7. [...] Record processing Circuit 9 ... motor 10 ... slider 204 ... spectral detector 23 ... adder 24, 33 ... subtractor 25 ... head amplifier 26 ... shaft motor servo 30 ... information material 31, 32 ... amplifier 34 ... two Yuanhua circuit 40 ... Road skip generation circuit 50 ... AND circuit 5 1 ... Gate pulse generation circuit 60 ... LPP interval detection circuit 61 ... Oscilloscope 62 ... Personal computer 71 ... Comparer 72 ......... 1/4 frequency division circuit 73 ... counter 91 ... A / D converter 92 ... control circuit 93 ... sample memory 94 ... display memory 95 ... X driver 96 ... Y driver

25 200307283 玖, description of the invention 97 ... display panel 98 ... operation unit 99 ... interface 101 ... disc substrate

10 2 ... concave ground track 103 ... convex groove track 104 --- LPP

26

Claims (1)

'Scope of patent application: a pre-pit pit waveform measuring device for an optical recording medium. The optical recording medium has a recording area on which repeatedly formed pre-pits and pits representing track-related information are repeatedly formed between tracks. An information pre-pit, comprising: a light detection device having a photosensitive surface, which is divided into first and second photosensitive surfaces in the tangential direction of the track force, and is used for the first and second photosensitive A surface to receive the reflected light of a laser beam irradiated onto the recording surface, and to generate first and second light detection signals corresponding to the photosensitivities of the first and second photosensitive surfaces, respectively; a subtraction device, which uses Calculate the difference between the first and second light detection signals generated by the light detection device to generate a push-pull signal; the heart-shell extraction device is used to measure the push-pull signal corresponding to the synchronous pre-pit Synchronous signal component, and every time the synchronization signal is detected, it will be used to capture a signal component to be measured in the push-pull signal. The signal component is detected from the synchronous signal component. There is a center at the beginning of time when a time interval between the synchronous pre-pit and the information pre-pit has passed; a track jump device for forming a position on which a laser beam jumps on the track in the recording area Irradiation; and a prohibition control device for prohibiting for a period including at least one orbital jump period in which the laser beam is used for orbital jump with the execution jump dress and a first predetermined period after the operation jump period The operating device captures a signal component to be measured. For example, the device in the scope of patent application No. 1 in which the recording area is a raised area. 3. If the device is the oldest in the scope of the patent application, the capture device does not detect the synchronization corresponding to the push-pull signal within a period starting from the time before the second predetermined period before the _I. The component of the synchronization signal of the pre-coating recess is until the first predetermined period has passed. 10 15 20 4. The device according to item 3 of the scope of patent application, wherein each of the first and second predetermined cycles is longer than the time interval between the synchronous pre-pit and the information pre-pit. 5 · If the scope of patent application is the first! In the device of this item, the execution jump period is a period determined by the 8 characteristics of the -tracking error signal. 6. As described in the patent application No. 1 ^, the device ′, which is a swing orbit, swings at a predetermined frequency, and. The HI extraction device detects the time interval between the synchronous pre-pit and the information pre-pit according to the cycle of the push-pull signal. 7. According to the patent application No. 1 of the scope of clothing, it further includes a display device for displaying the ingredients to be captured by the capturing device. 8. As for the clothing in item 1 of the scope of the patent application, the orbital jumping device makes the position of the laser beam jump early to perform reading repeatedly from the same channel. Track 9. A method for shifting the pit wave shape of an optical recording medium. The optical recording medium has a recording ° 亥 ^ Η Ψ ^ ^ β-i, 5, which repeatedly rises between the tracks to represent a correlation. The synchronous pre-pit and information pre-pit of the track shell Λ include the following steps: 28 200307283 The scope of patent application is that a light-sensitive surface receives a reflected light of a laser beam irradiated onto the recording surface. The surface is divided into first and second light-sensitive surfaces in the tangent direction of the track, and corresponding responses are generated. First and second light-sensitive signals on the first and second light-sensitive surfaces; 5 calculating a difference between the first and second light-detecting signals generated by the light-detecting device to generate a push-pull Signal; Detect the synchronous signal component corresponding to the synchronous pre-pit in the push-pull signal, and each time the synchronous signal component is detected, a signal component in the push-pull signal to be measured is retrieved. The time when the No. 10 component is detected starts to pass a time interval between the synchronous pre-pit and the information pre-pit, and has a center in time; a position is formed on which a laser beam jumps on the track in the recording area Irradiation; and during orbital jumps including at least one 15-track orbital jump using the orbital jumper and after The capturing device during a predetermined period of piece goods must prohibit capturing of the signal component to be measured. 29