JPH0252242A - Disk defect detecting circuit - Google Patents
Disk defect detecting circuitInfo
- Publication number
- JPH0252242A JPH0252242A JP20286188A JP20286188A JPH0252242A JP H0252242 A JPH0252242 A JP H0252242A JP 20286188 A JP20286188 A JP 20286188A JP 20286188 A JP20286188 A JP 20286188A JP H0252242 A JPH0252242 A JP H0252242A
- Authority
- JP
- Japan
- Prior art keywords
- disk
- limit value
- detection
- circuit
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000007547 defect Effects 0.000 title claims abstract description 38
- 238000001514 detection method Methods 0.000 claims abstract description 76
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 230000007257 malfunction Effects 0.000 abstract 1
- 230000003287 optical effect Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/9506—Optical discs
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Manufacturing Optical Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光ディスク等の光学的ディスクの欠陥を検出す
るディスク欠陥検出回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk defect detection circuit for detecting defects in an optical disk such as an optical disk.
従来、欠陥検出回路は被検物を光ビームで走査してその
反射光量を受光素子で検出し、この検出信号を固定の検
出レベル（」二限値と下限値）と比較することにより被
検物上の欠陥を検出している。Conventionally, defect detection circuits scan an object to be inspected with a light beam, detect the amount of reflected light with a light receiving element, and compare this detection signal with fixed detection levels (two limit values and a lower limit value). Detecting defects on objects.
上記従来の欠陥検出回路では検出レベルが固定している
ので、被検物の反射光量が変動することにより誤検出を
行い、かつディスク上の欠陥を検出する場合にはディス
ク上の番地を示す連続番号や、書き込みがあったことを
示すフラグ等によって構成されるＴ Ｄ （Ｉ ｄｅｎ
ｔｊｆｊｃａｔｉｏｎ）部を欠陥として誤って検出して
しまう。In the conventional defect detection circuit described above, the detection level is fixed, so erroneous detection may occur due to fluctuations in the amount of reflected light from the object to be inspected. T D (I den
tjfjcation) portion is mistakenly detected as a defect.
本発明は上記欠点を除去し、ディスクの反射光量の変動
やディスク」二のＩＤ部による誤検出を行わないディス
ク欠陥検出回路を提供することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk defect detection circuit that eliminates the above-mentioned drawbacks and does not cause erroneous detection due to fluctuations in the amount of reflected light on the disk or the ID section of the disk.
上記目的を達成するために、請求項１の発明はディスク
に光ビームを照射してその反射光量を検出する検出手段
と、この検出手段の検出信号が入力されるローパスフィ
ルタと、このローパスフィルタの出力信号に追従して上
限値及び下限値を発生する検出レベル発生手段と、この
検出レベル発生手段からの上限値及び下限値と前記検出
手段からの検出信号とを比較して前記ディスクの欠陥を
検出する比較手段とを備えたものである。In order to achieve the above object, the invention of claim 1 includes: a detection means for irradiating a light beam onto a disk and detecting the amount of reflected light; a low-pass filter to which a detection signal of the detection means is input; a detection level generating means for generating an upper limit value and a lower limit value following an output signal, and comparing the upper limit value and lower limit value from the detection level generating means with the detection signal from the detecting means to detect a defect in the disk. and comparison means for detection.
請求項２の発明は請求項」の発明において、前記検出手
段の検出信号からディスク上のＩＤ部と他の部分とを区
別するＩＤ判定手段と、このＩＤ判定手段の出力信号に
より前記ディスク」二のＩＤ部以外の部分についてのみ
欠陥検出を行わせる制御手段とを有するものである。The invention according to claim 2 is the invention according to claim 1, further comprising an ID determining means for distinguishing between an ID part and other parts on the disc based on a detection signal of the detecting means, and an output signal of the ID determining means to detect the disc. and a control means for causing defect detection to be performed only in a portion other than the ID section.
請求項３の発明は請求項１の発明において、前記検出手
段の検出信号から前記ディスク上のＩＤ部と他の部分と
を区別するＩＤ判定手段と、このＩＤ判定手段の出力信
号により前記検出レベル発生手段の入力信号を前記ディ
スク」二のＩＤ部に対してホール１−シ又は所定の検出
レベルに固定する検出レベル固定化手段とを有するもの
である。The invention according to claim 3 is the invention according to claim 1, further comprising an ID determining means for distinguishing between an ID section and other parts on the disk from a detection signal of the detecting means, and an output signal of the ID determining means to determine the detection level. The detection level fixing means fixes the input signal of the generating means to a predetermined detection level with respect to the ID section of the disk.
請求項１の発明では検出手段がディスクに光ビームを照
射してその反射光量を検出し、この検出手段の検出信号
がローパスフィルタに入力される。In the first aspect of the invention, the detection means irradiates the disc with a light beam and detects the amount of reflected light, and the detection signal of this detection means is input to the low-pass filter.
検出レベル発生手段はローパスフィルタの出力信号に追
従して上限値及び下限値を発生し、比較手段は検出レベ
ル発生手段からの」二限値及び下限値と検出手段からの
検出信号とを比較してディスクの欠陥を検出する。The detection level generating means generates an upper limit value and a lower limit value by following the output signal of the low-pass filter, and the comparing means compares the two limit values and lower limit value from the detection level generating means with the detection signal from the detecting means. detect disc defects.
また請求項２の発明では請求項１の発明において、ＩＤ
判定手段が検出手段の検出信号からディスク上のＩＤ部
と他の部分とを区別し、制御手段がＩＤ判定手段の出力
信号によりディスク」二のＩＤ部以外の部分についての
み欠陥検出を行わせる。Further, in the invention of claim 2, in the invention of claim 1, ID
The determining means distinguishes between the ID part and other parts on the disk based on the detection signal of the detecting means, and the control means causes defect detection to be performed only on the part other than the ID part of the disk based on the output signal of the ID determining means.
さらに請求項３の発明では請求項１の発明において、Ｉ
Ｄ判定手段が検出手段の検出信号からディスク上のＩＤ
部と他の部分とを区別し、検出レベル固定化手段がＩＤ
判定手段の出力信号により検出レベル発生手段の入力信
号をディスク−にの１０部に対してホールドし又は所定
の検出レベルに固定する。Furthermore, in the invention of claim 3, in the invention of claim 1, I
D judgment means detects the ID on the disk from the detection signal of the detection means.
The detection level fixing means distinguishes between the ID part and other parts.
The input signal of the detection level generating means is held or fixed at a predetermined detection level for 10 copies of the disk based on the output signal of the determining means.
第２図は本発明の一実施例を示す。 FIG. 2 shows an embodiment of the invention.
この実施例は光デイスク上の欠陥を検出する例である。This embodiment is an example of detecting defects on an optical disk.
ピックアップ１２は光ディスク１１に裏面側から半導体
レーザによる光ビームを照射してその反射光を受光素子
で受光することにより反射光量を検出し、光ディスク１
１がモータにより回転駆動されるとともにピックアップ
１２がシーク機構により光ディスク１１の半径方向へ移
動することによりピンクアップ１２の半導体レーザによ
る光ビー１１が光ディスク１１の１−ラック」二を移動
する。制御回路１３はピックアップ１２における」二記
受光素子からの信号により上記光ビームのフォーカシン
グ及び１へランキングを行い、かつＲＦ倍信号言われる
光ディスク１１の反射光量の総和に比例した電圧を出力
する。欠陥検出回路１４は制御回路１３からのＲＦ倍信
号基準信号と比較して光ディスク１１」二の反射光量が
下がる位置と長さを演算する。The pickup 12 irradiates the optical disc 11 with a light beam from a semiconductor laser from the back side and detects the amount of reflected light by receiving the reflected light with a light receiving element.
1 is rotationally driven by a motor, and the pickup 12 is moved in the radial direction of the optical disk 11 by a seek mechanism, so that the optical beam 11 produced by the semiconductor laser of the pink-up 12 moves from 1 to 2 racks on the optical disk 11. The control circuit 13 performs focusing and ranking of the light beam to 1 based on the signal from the second light receiving element in the pickup 12, and outputs a voltage proportional to the sum of the amount of light reflected from the optical disk 11, called an RF multiplication signal. The defect detection circuit 14 compares the RF multiplied signal reference signal from the control circuit 13 and calculates the position and length at which the amount of reflected light on the optical disk 11'2 decreases.
第１図は上記欠陥検出回路１４の構成を示す。FIG. 1 shows the configuration of the defect detection circuit 14 described above.
制御回路１３からの第６図（１）に示すようなＲＦ倍信
号ローパスフィルタ１５により低周波分の全体レベルの
変動が抽出され、上限値発生回路１６がロバスフィルタ
１５の出力信号に追従して」二限値を発生すると同時に
下限値発生回路１７がローパスフィルタ１５の出力信号
に追従して下限値を発生する。The RF multiplied signal from the control circuit 13 as shown in FIG. At the same time as the second limit value is generated, the lower limit value generating circuit 17 follows the output signal of the low pass filter 15 and generates the lower limit value.
そして制御回路１３からのＲＦ倍信号バッファ回路１８
を経てウィンドコンパレータからなる比較回路１９によ
り上限値発生回路１６からの上限値、下限値発生回路１
７からの下限値と比較することにより、光ディスク１１
」二の欠陥を検出する。この比較回路１９の出力信号は
基準パルス発生回路２０からの基準パルスによりアント
ゲ−Ｉ・２１を通過してカウンタ２２によりカランＩ・
される。従来は第７図に示すように」二限値発生回路１
６及び下限値発生回路１７が固定の上限値及び下限値を
発生していたので、比較回路１９の出力信号に被検物の
反射光量の変動による誤差（図示斜線部分）を生した。And RF double signal buffer circuit 18 from control circuit 13
The upper limit value from the upper limit value generation circuit 16 and the lower limit value generation circuit 1
By comparing with the lower limit value from 7, the optical disc 11
” Detect the second defect. The output signal of this comparator circuit 19 is passed through an ant game I.
be done. Conventionally, as shown in FIG. 7, the two-limit value generation circuit 1
6 and the lower limit value generation circuit 17 generate fixed upper and lower limit values, an error (the shaded area in the figure) occurs in the output signal of the comparison circuit 19 due to fluctuations in the amount of reflected light from the test object.
しかし、この実施例では」二限値発生回路１６及び下限
値発生回路１７が第６図（２）のようにローパスフィル
タ１５の出力信号に追従して上限値及び下限値を発生す
るので、比較回路１９の出力信号に光ディスク１１の反
射光量の変動による誤差が生じない。However, in this embodiment, the second limit value generating circuit 16 and the lower limit value generating circuit 17 generate the upper limit value and the lower limit value by following the output signal of the low-pass filter 15 as shown in FIG. No errors occur in the output signal of the circuit 19 due to fluctuations in the amount of light reflected from the optical disc 11.
ところが、一般に光ディスク１１はＩＤ部があり、上記
実施例ではそのＩＤ部により上限値発生回路１６及び下
限値発生回路Ｊ７の上限値及び下限値が第６図（２）の
ように正常な位置につくまでに誤差を生ずるという欠点
がある。However, the optical disc 11 generally has an ID section, and in the above embodiment, the ID section allows the upper limit value and lower limit value of the upper limit value generation circuit 16 and the lower limit value generation circuit J7 to be placed in the normal position as shown in FIG. 6 (2). It has the disadvantage that errors occur before it is applied.
第３図はその欠点を除去した本発明の他の実施例におけ
る欠陥検出回路を示し、第１図と同一部分には同一符号
が付しである。FIG. 3 shows a defect detection circuit according to another embodiment of the present invention in which this drawback has been eliminated, and the same parts as in FIG. 1 are given the same reference numerals.
この実施例は上記実施例において欠陥検出回路１４とし
て第３図に示すものを用いた例であり、１０判定部２３
は制御回路］３がらのＲＴ？倍信号より光ディスク１１
」二におけるＩＤ部をデータ部と区別して検出する。ゲ
ート２４は１０判定部２３から第６図（３）のようにデ
ィスク１１上のＩＤ部で低レベルになってディスク１１
」二のデータ部で高レベルとなる信号が入力されると共
に、基準パルス発生回路２゜からの基準パルス及び比較
回路１９の出力信号が入力され、制御回路Ｉ３からＲＦ
倍信号おけるディスク１１上のデータ部に対応する部分
が出力されていて基準パルス発生回路２０からの基準パ
ルスが入力されたときに比較回路１９の出力信号を通過
させる。This embodiment is an example in which the defect detection circuit shown in FIG. 3 is used as the defect detection circuit 14 in the above embodiment.
is the control circuit] 3-piece RT? Optical disc 11 from double signal
The ID part in ``2'' is detected separately from the data part. As shown in FIG. 6 (3), the gate 24 becomes a low level at the ID section on the disk 11 from the 10 determination section 23 and the disk 11
''A high level signal is input in the second data section, and at the same time, the reference pulse from the reference pulse generation circuit 2° and the output signal of the comparator circuit 19 are input, and the RF signal is input from the control circuit I3.
When a portion of the doubled signal corresponding to the data portion on the disk 11 is output and a reference pulse from the reference pulse generation circuit 20 is input, the output signal of the comparison circuit 19 is passed.
このゲート２４の出力信号はカウンタ２２によりカラン
１〜される。またゲー１〜２４は制御回路１３がらＲＦ
倍信号おけるディスク１１」−のＩＤ部に対応する部分
が出力されているときにはオフとなり、比較回路］９の
出力信号はゲート２４により阻止されてカウンタ２２で
カラン１〜されない。The output signal of this gate 24 is counted by the counter 22 from 1 to 1. In addition, the gates 1 to 24 are connected to the control circuit 13 using RF
When the portion corresponding to the ID part of the disk 11'' in the double signal is being output, it is turned off, and the output signal of the comparator circuit 9 is blocked by the gate 24 and is not counted by the counter 22.
しかし、この実施例ではゲート２４がローパスフィルタ
１５の時定数たけ実際のＩＤ部の長さに相当する時間よ
り長く閉じているので、データ部の欠陥検出を行える長
さが短くなるという欠点がある。However, in this embodiment, since the gate 24 is closed longer than the time corresponding to the actual length of the ID section by the time constant of the low-pass filter 15, there is a drawback that the length over which defects in the data section can be detected is shortened. .
第４図、第５図はその欠点を除去した本発明の他の各実
施例における欠陥検出回路を示し、第３図と同一部分に
は同一符号が付しである。FIGS. 4 and 5 show defect detection circuits in other embodiments of the present invention in which the above drawbacks have been eliminated, and the same parts as in FIG. 3 are given the same reference numerals.
第４図の実施例は上記実施例において欠陥検出回路１４
として第４図に示すものを用いた例であり、ケー１−２
４が閉じている間はローパスフィルタ１５の入力電圧を
固定するものである。アナログスイッチ２５はより判定
部２３の出力信号によりディスク］１」二のＩＤ部でオ
フになって制御回路１３からローパスフィルタ１５への
ＲＦ倍信号阻止し、ディスク１１上のデータ部でオンし
て制御回路１３からローパスフィルタ１５へのＲＦ倍信
号通過させる。アナログスイッチ２６はＩＤ判定部２３
の出力信号がインバータ２７で反転されて入力されるこ
とによりディスク］■」二のＩＤ部でオンになって固定
の基準電圧をロバスフィルタ］５へ入力させ、ディスク
１目二のデ−タ部でオフして固定基準電圧のローパスフ
ィルタ］５への入力を阻止する。したがってゲー１−２
４が開いてから」二限値発生回路１６及び下限値発生回
路１７の」二限値及び下限値が本来の値になるまでの時
間が短くなり、欠陥検出を行えるデータ部の長さが長く
なる。The embodiment of FIG. 4 is the defect detection circuit 14 in the above embodiment.
This is an example using the one shown in Fig. 4, and Case 1-2.
4 is closed, the input voltage of the low-pass filter 15 is fixed. The analog switch 25 is turned off at the ID section of the disk 1 and 2 by the output signal of the determination section 23 to block the RF multiplied signal from the control circuit 13 to the low-pass filter 15, and turned on at the data section of the disk 11. The RF multiplied signal is passed from the control circuit 13 to the low-pass filter 15. The analog switch 26 is the ID determination section 23
The output signal of the disk is inverted by the inverter 27 and inputted, thereby turning on the ID section of the second disk and inputting a fixed reference voltage to the robust filter 5, which inverts the data of the first and second disks. 5 to block input of the fixed reference voltage to the low-pass filter]5. Therefore, game 1-2
The time it takes for the second limit value and lower limit value of the second limit value generation circuit 16 and lower limit value generation circuit 17 to reach their original values after the second limit value generation circuit 16 and lower limit value generation circuit 17 become the original values is shortened, and the length of the data section in which defects can be detected is longer. Become.
第５図の実施例は上記実施例において欠陥検出回路１４
として第５図に示すものを用いた例であり、ゲー１〜２
４が閉している間はその閉じる瞬間のローパスフィルタ
１５の入力電圧を保持するものである。The embodiment of FIG. 5 is a defect detection circuit 14 in the above embodiment.
This is an example using the one shown in Fig. 5 as
4 is closed, the input voltage of the low-pass filter 15 at the moment of closing is held.
ワンパルス発生回路２８はＩＤ判定部２３の出力信号に
よりディスク１］上のＩＤ部の最初でパルスを１つ発生
し、このパルスによりサンプルホール１〜回路２９が制
御回路］３がらのＲＦ倍信号サンプルしてホールｊくす
る。このサンプルホール１−回路２９の出力はアナログ
スイッチ２６によりディスク１１」−の１０部で基準電
圧としてローパスフィルタ１５へ入力される。The one-pulse generation circuit 28 generates one pulse at the beginning of the ID section on the disk 1 based on the output signal of the ID determination section 23, and this pulse causes the sample holes 1 to 29 to generate RF multiplied signal samples from the control circuit 3. and then go to the hall. The output of this sample hole 1-circuit 29 is input to the low-pass filter 15 as a reference voltage at 10 parts of the disk 11'' by an analog switch 26.
以」二のようにｌｈ求項１の発明ではディスクに光ビー
ムを照射してその反射光量を検出する検出手段と、この
検出手段の検出信号が入力されるローパスフィルタと、
このローパスフィルタの出力信号に追従して上限値及び
下限値を発生する検出レベル発生手段と、この検出レベ
ル発生手段からの上限値及び下限値と前記検出手段から
の検出信号とを比較して前記ディスクの欠陥を検出する
比較手段とを備えたので、ディスクの反射光量の変動に
よる誤検出を行わなくなる。As shown in ``2'', the invention of item 1 includes: a detection means for irradiating a light beam onto a disc and detecting the amount of reflected light; a low-pass filter to which a detection signal of the detection means is input;
A detection level generating means generates an upper limit value and a lower limit value by following the output signal of the low-pass filter, and the upper limit value and lower limit value from this detection level generating means are compared with the detection signal from the detecting means, Since the present invention includes a comparison means for detecting defects on the disk, erroneous detection due to fluctuations in the amount of light reflected from the disk is not performed.
また請求項２の発明では請求項１の発明において、前記
検出手段の検出信号からディスク」二のＩＤ部と他の部
分とを区別するＩＤ判定手段と、このＩＤ判定手段の出
力信号により前記ディスク上のＩＤ部以外の部分につい
てのみ欠陥検出を行わせる制御手段とを有するので、デ
ィスク上のＩＤ部による誤検出も行わなくなる。Further, in the invention according to claim 2, in the invention according to claim 1, there is provided an ID determining means for distinguishing between an ID portion of the disk and other portions based on the detection signal of the detecting means, and an output signal of the ID determining means to determine whether the disk is Since the disk drive apparatus includes a control means for detecting defects only in parts other than the ID part on the disk, erroneous detection by the ID part on the disk is also prevented.
さらに請求項３の発明では請求項１の発明において、前
記検出手段の検出信号から前記ディスク上のＩＤ部と他
の部分とを区別するＩＤ判定手段と、このＩＤ判定手段
の出力信号により前記検出レベル発生手段の入力信号を
前記ディスク上のＩＤ部に対してホールドし又は所定の
検出レベルに固定する検出レベル固定化手段とを有する
ので、ディスク上の欠陥検出を行えるデータ部の長さが
長くなる。Further, in the invention according to claim 3, in the invention according to claim 1, there is provided an ID determining means for distinguishing between an ID part and other parts on the disk from a detection signal of the detecting means, and an output signal of the ID determining means for detecting the ID part. and detection level fixing means for holding the input signal of the level generating means for the ID section on the disk or fixing it at a predetermined detection level, the length of the data section that can detect defects on the disk is long. Become.
第１図は本発明の一実施例における欠陥検出回路を示す
ブロック図、第２図は同実施例を示すブロック図、第３
図乃至第５図は本発明の他の各実施例における欠陥検出
回路を示すブロック図、第６図は上記実施例の各信号波
形を示す波形図、第７図は従来の欠陥検出回路における
各信号波形を示す波形図である。FIG. 1 is a block diagram showing a defect detection circuit in one embodiment of the present invention, FIG. 2 is a block diagram showing the same embodiment, and FIG.
5 to 5 are block diagrams showing defect detection circuits in other embodiments of the present invention, FIG. 6 is a waveform diagram showing each signal waveform in the above embodiment, and FIG. 7 is a block diagram showing each signal waveform in the conventional defect detection circuit. FIG. 3 is a waveform diagram showing signal waveforms.
Claims (1)
する検出手段と、この検出手段の検出信号が入力される
ローパスフィルタと、このローパスフィルタの出力信号
に追従して上限値及び下限値を発生する検出レベル発生
手段と、この検出レベル発生手段からの上限値及び下限
値と前記検出手段からの検出信号とを比較して前記ディ
スクの欠陥を検出する比較手段とを備えたディスク欠陥
検出回路。 ２、前記検出手段の検出信号からディスク上のＩＤ部と
他の部分とを区別するＩＤ判定手段と、このＩＤ判定手
段の出力信号により前記ディスク上のＩＤ部以外の部分
についてのみ欠陥検出を行わせる制御手段とを有する請
求項１記載のディスク欠陥検出回路。 ３、前記検出手段の検出信号から前記ディスク上のＩＤ
部と他の部分とを区別するＩＤ判定手段と、このＩＤ判
定手段の出力信号により前記検出レベル発生手段の入力
信号を前記ディスク上のＩＤ部に対してホールドし又は
所定の検出レベルに固定する検出レベル固定化手段とを
有する請求項１記載のディスク欠陥検出回路。[Claims] 1. A detection means for irradiating a light beam onto the disc and detecting the amount of reflected light; a low-pass filter to which the detection signal of the detection means is input; and a low-pass filter that follows the output signal of the low-pass filter. a detection level generating means for generating an upper limit value and a lower limit value; and a comparing means for detecting a defect in the disk by comparing the upper limit value and lower limit value from the detection level generating means with a detection signal from the detecting means. Equipped with a disk defect detection circuit. 2. ID determining means for distinguishing between the ID part and other parts on the disk based on the detection signal of the detecting means, and detecting defects only in the part other than the ID part on the disk using the output signal of the ID determining means. 2. The disk defect detection circuit according to claim 1, further comprising a control means for controlling the disk defect detection circuit. 3. ID on the disk from the detection signal of the detection means
an ID determining means for distinguishing one part from another part, and an output signal of the ID determining means to hold the input signal of the detection level generating means for the ID part on the disk or fix it at a predetermined detection level. 2. The disk defect detection circuit according to claim 1, further comprising detection level fixing means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63202861A JP2774516B2 (en) | 1988-08-15 | 1988-08-15 | Disk defect detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63202861A JP2774516B2 (en) | 1988-08-15 | 1988-08-15 | Disk defect detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0252242A true JPH0252242A (en) | 1990-02-21 |
| JP2774516B2 JP2774516B2 (en) | 1998-07-09 |
Family
ID=16464410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63202861A Expired - Fee Related JP2774516B2 (en) | 1988-08-15 | 1988-08-15 | Disk defect detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2774516B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02166646A (en) * | 1988-12-20 | 1990-06-27 | Csk Corp | Inspection instrument for defect of optical storage medium |
| WO2003102563A1 (en) * | 2002-05-30 | 2003-12-11 | Matsushita Electric Industrial Co., Ltd. | Method for detecting foreign matter on object, device for detecting foreign matter on object, and optical disc apparatus |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60107749A (en) * | 1983-11-15 | 1985-06-13 | Matsushita Electric Ind Co Ltd | Optical disk inspecting device |
-
1988
- 1988-08-15 JP JP63202861A patent/JP2774516B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60107749A (en) * | 1983-11-15 | 1985-06-13 | Matsushita Electric Ind Co Ltd | Optical disk inspecting device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02166646A (en) * | 1988-12-20 | 1990-06-27 | Csk Corp | Inspection instrument for defect of optical storage medium |
| WO2003102563A1 (en) * | 2002-05-30 | 2003-12-11 | Matsushita Electric Industrial Co., Ltd. | Method for detecting foreign matter on object, device for detecting foreign matter on object, and optical disc apparatus |
| US7239588B2 (en) | 2002-05-30 | 2007-07-03 | Matsushita Electric Industrial Co., Ltd. | Method and apparatus for detecting foreign body on object surface, and optical disk apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2774516B2 (en) | 1998-07-09 |
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| LAPS | Cancellation because of no payment of annual fees |