KR100230237B1 - Optical pickup for recording and reproducing - Google Patents
Optical pickup for recording and reproducing Download PDFInfo
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- KR100230237B1 KR100230237B1 KR1019940018931A KR19940018931A KR100230237B1 KR 100230237 B1 KR100230237 B1 KR 100230237B1 KR 1019940018931 A KR1019940018931 A KR 1019940018931A KR 19940018931 A KR19940018931 A KR 19940018931A KR 100230237 B1 KR100230237 B1 KR 100230237B1
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1362—Mirrors
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1372—Lenses
- G11B7/1374—Objective lenses
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1395—Beam splitters or combiners
Abstract
광로를 직각으로 바꾸기 위해 사용되는 반사경을 채용한 기록재생용 광픽업이 개시되어 있다. 개시된 반사경은 진동이나 경시변화 등에 대응하여 입사광에 대한 반사광의 광축변화를 방지할 수 있도록 설계된 것으로서, 입사되는 광이 2회반사하도록 두 반사면을 가지며 두 반사면의 사이각이 135도이다. 따라서 일측 반사면의 미소회전에 의한 광축틸트가 타측 반사면의 미소회전에 의하여 상쇄되어, 입사광에 대한 반사광의 광축틸트를 방지한다. 따라서 광픽업의 광축 틸트에 의한 영향을 제거하여 기록재생 및 제어특성을 향상시킬 수 있는 것이다.Disclosed is an optical pickup for recording and reproducing employing a reflector used to change an optical path at a right angle. The disclosed reflector is designed to prevent a change in the optical axis of the reflected light with respect to the incident light in response to vibrations or changes over time, and has two reflecting surfaces so that the incident light is reflected twice, and the angle between the two reflecting surfaces is 135 degrees. Accordingly, the optical axis tilt due to the small rotation of the one reflecting surface is canceled by the small rotation of the other reflecting surface, thereby preventing the optical axis tilt of the reflected light with respect to the incident light. Therefore, the recording reproduction and control characteristics can be improved by removing the influence of the optical axis tilt of the optical pickup.
Description
제1도는 기록재생용 광픽업을 보인 평면도.1 is a plan view showing an optical pickup for recording and reproducing.
제2도는 제1도에 나타난 종래 반사경을 설명하는 측면도.2 is a side view illustrating the conventional reflector shown in FIG.
제3도는 본 발명의 기록재생용 광픽업에 채용된 반사경의 일 실시예를 보인 측면도.3 is a side view showing one embodiment of a reflecting mirror employed in the optical pickup for recording and reproducing of the present invention.
제4도는 본 발명의 기록재생용 광픽업에 채용된 반사경의 다른 실시예를 보인 측면도.4 is a side view showing another embodiment of a reflector employed in the optical pickup for recording and reproducing of the present invention.
제5도는 본 발명의 기록재생용 광픽업에 채용된 반사경의 또 다른 실시예를 보인 측면도.5 is a side view showing another embodiment of the reflector employed in the recording and reproducing optical pickup of the present invention.
제6도는 제4도에 도시된 바와같이 미소회전에 의한 광축틸트를 설명하는 측면도.6 is a side view illustrating an optical axis tilt by micro rotation as shown in FIG.
제7도는 제5도에 도시된 반사경의 미소회전에 의한 광축틸트를 설명하는 측면도.FIG. 7 is a side view illustrating an optical axis tilt caused by the small rotation of the reflector shown in FIG.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
10,20,30 : 반사경 11,21,31 : 일측 반사면10,20,30: reflector 11,21,31: one side reflecting surface
12,22,32 : 타측반사면12,22,32: other side reflector
본 발명은 기록재생용 광픽업에 관한 것으로서, 상세하게는 특히 진동이나 경시변화 등에 대응하여 입사광에 대한 반사광의 광축변화를 방지할 수 있도록 설계된 반사경을 채용한 기록재생용 광픽업에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for recording and reproducing, and more particularly, to an optical pickup for recording and reproducing employing a reflector designed to prevent a change in the optical axis of reflected light with respect to incident light in response to vibrations and changes over time.
기록재생용 광픽업과 같은 광학장치는 종종 각 부품을 경유하는 광축의 틸트현상에 의하여 오동작을 하게 된다. 광축의 틸트현상은 여러 가지 원인이 있겠으나, 예를 들면 광축을 꺽기 위해 놓인 반사경(또는 반사프리즘)이 실질적으로 고정되지 않고 외부 진동 등에 의하여 흔들리거나 경시변화 등에 기여된다. SHG(second harmonic generator) 광원으로 사용하는 고밀도 기록재생용 광픽업의 경우는 광로가 길므로 미소한 광축틸트에도 오동작하는 일이 많다.Optical devices, such as optical pickup for recording and reproduction, often malfunction due to tilting of the optical axis via each component. Tilt phenomenon of the optical axis may have various causes, but for example, the reflector (or reflecting prism) placed to break the optical axis is not substantially fixed, and is shaken by external vibration, or contributes to changes over time. In the case of optical pickup for high density recording and reproduction used as a second harmonic generator (SHG) light source, the optical path is long, so that even a small optical axis tilt often malfunctions.
제1도는 SHG 광원을 사용하는 기록재새용 광픽업을 보인 것이다. 도시된 광픽업에 있어서 광원(1)과 광변조기(3) 사이의 제1반사경(2)과, 빔확대기(4)와 빔스프리터(6) 사이의 제2반사영(5), 그리고 빔스프리터(6)와 대물렌즈(8) 사이의 캐리지(7)상에 설치되는 도시되지 않은 제3반사경이 각각 설치된다. 광원(1)에서 방출되는 광은 제1반사경(2)을 반사한 후 광변조기(3)에 이르러서 소정의 광신호로 변조된다. 변조된 광은 빔확대기(4)에 의하여 평행광으로 된 후 제2반사경(5)을 반사하여 빔스프리터(6)를 향하며, 빔스프리터(6)를 직진한 다음 이송모터의 캐리지(7)에 탑재된 제3반사경을 반사한 후 대물렌즈(8)에 의하여 광디스크(9)에 집속된다. 한편, 광디스(9)에서 반사되는 광은 다시 상기한 대물렌즈(8)와 제3반사경을 경유하여 빔스프리터(6)로 진행하며, 그 빔스프리터(6)에서 반사되어 광검출기(10)에 수광된다. 이와 같은 광픽업에 있어서, 상기한 제1, 제2 및 제3반사경이 외부의 충격 등에 기인하여 제2도와 같이 Δθ만큼 회전하면, 그 반사경에 대한 입사광의 입사각도 Δθ만큼 변화되고 그 반사광의 출사각은 2Δθ만큼 변화된다.1 shows an optical pickup for recording materials using an SHG light source. In the illustrated optical pickup, the first reflector 2 between the light source 1 and the optical modulator 3, the second reflector 5 between the beam expander 4 and the beam splitter 6, and the beam splitter Third reflecting mirrors (not shown) provided on the carriage 7 between the 6 and the objective lens 8 are respectively provided. The light emitted from the light source 1 reflects the first reflector 2 and reaches the optical modulator 3 to be modulated into a predetermined optical signal. The modulated light becomes parallel light by the beam expander 4 and then reflects the second reflector 5 to the beam splitter 6, goes straight through the beam splitter 6, and then onto the carriage 7 of the transfer motor. After reflecting the mounted third reflecting mirror, it is focused on the optical disk 9 by the objective lens 8. On the other hand, the light reflected from the optical device 9 passes back to the beam splitter 6 via the objective lens 8 and the third reflecting mirror, and is reflected by the beam splitter 6 to reflect the photodetector 10. Is received. In such optical pickup, when the first, second and third reflecting mirrors rotate by Δθ as shown in FIG. 2 due to external impact or the like, the incident angle of incident light with respect to the reflecting mirror is changed by Δθ and the reflected light is emitted. The angle is changed by 2Δθ.
이러한 반사경의 회전각도는 미소한 값이지만, 그 반사경으로부터 광디스크까지의 광로가 상당히 길므로 광디스크에서의 영향은 심각해진다. 즉, 대물렌즈에 입사하는 광은 비축으로서 광디스크에 형성되는 광스폿의 수차가 커져 기록재생특성이 저하되며, 또한 그 광디스크로부터 반사되는 반사광도 틸트되어 이를 수광하는 광검출기의 신호가 불안정하고 결국 서로 에러를 유발하는 문제점이 있는 것이다.Although the angle of rotation of such a reflector is a small value, since the optical path from the reflector to the optical disk is considerably long, the influence on the optical disk becomes serious. That is, the light incident on the objective lens is a stockpile, and the aberration of the optical spot formed on the optical disk becomes large, and thus the recording and reproduction characteristics are deteriorated. Also, the reflected light reflected from the optical disk is tilted, so that the signals of the photodetector receiving the optical signal are unstable and eventually become mutually incompatible. There is a problem that causes an error.
본 발명의 목적은 상기한 광축틸트에 의한 제반 문제점을 해결하고자 진동이나 경시변화 등에 의한 미소회전에도 입사광에 대한 반사광의 광축의 위치가 변동되지 않도록 하는 반사경을 채용한 기록재생용 광픽업을 제공하는데 있다.SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup for recording and reproduction employing a reflector such that the position of the optical axis of the reflected light with respect to the incident light does not change even when the micro-rotation due to vibration or aging changes to solve the problems caused by the optical axis tilt. have.
상기한 목적을 달성하기 위한 본 발명은, 광원과; 상기 광원에서 조사된 광빔을 광신호로 변조하는 광변조기와; 광빔의 직경이 확장되도록 상기 광변조기에 의해 변조된 광빔을 확대시키는 빔확대기와; 광의 진행경로를 변환하는 빔스프리터와; 입사광을 광디스크에 집속시키기 위한 대물렌즈와; 상기 광원과 상기 광변조기 사이, 상기 빔확대기와 상기 빔스프리터 사이 및/또는 상기 빔스프리터와 대물렌즈 사이에 배치되어 입사광을 소정 각도로 반사시키는 적어도 하나의 반사경을 포함한 기록재생용 광픽업에 있어서, 상기 반사경은, 입사광에 대한 출사광의 출사각이 변동되지 않도록 입사광을 2회 반사시키기 위한 두 반사면을 가지며, 두 반사면 사이각이 135도 인 것을 특징으로 한다.The present invention for achieving the above object, a light source; An optical modulator for modulating the light beam irradiated from the light source into an optical signal; A beam expander for enlarging the light beam modulated by the light modulator so that the diameter of the light beam is expanded; A beam splitter for converting a traveling path of light; An objective lens for focusing incident light onto an optical disc; An optical pickup for recording and reproduction comprising at least one reflector disposed between the light source and the optical modulator, between the beam expander and the beam splitter, and / or between the beam splitter and the objective lens to reflect incident light at a predetermined angle. The reflector has two reflecting surfaces for reflecting the incident light twice so that the exit angle of the outgoing light with respect to the incident light does not vary, and the angle between the two reflecting surfaces is 135 degrees.
이와 같은 본 발명에 따르면, 진동이나 경시변화에 의한 회전시에, 예를 들면 2개의 반사면을 갖는 반사경에 있어서, 일측 반사면의 미소회전에 의하여 변화하는 광축의 틸트가 타측 반사면의 동일한 미소회전에 의하여 보상됨으로써 최종 반사광의 광축변화는 발생되지 않게 된다.According to the present invention as described above, in the case of a reflector having two reflecting surfaces, for example, when the rotation is caused by vibration or change over time, the tilt of the optical axis that is changed by the minute rotation of one reflecting surface is the same as that of the other reflecting surface. By compensation by rotation, the optical axis change of the final reflected light does not occur.
이러한 본 발명의 바람직한 실시예에 따른 기록재새용 광픽업을 첨부된 도면에 의거하여 상세하게 설명하면 다음과 같다.Referring to the recording pickup optical pickup according to a preferred embodiment of the present invention in detail based on the accompanying drawings as follows.
우선 본 발명에 따른 광픽업은 반사경을 제외하고는 제1도에 개시된 바와 같은 구성을 가진다. 즉, 본 발명에 따른 기록 재생용 광픽업은 광원(1)과, 상기 광원(1)에서 조사된 광빔을 광신호로 변조하는 광변조기(3)와, 광빔의 직경이 확장되로록 상기 광변조기(3)에 의해 변조된 광빔을 확대시키는 빔확대기(4) 및 광의 진행경로를 변환하는 빔스프리터(6)와, 입사광을 광디스크(9)에 집속시키는 대물렌즈(8)를 포함하여 구성된다. 또한, 상기 광원(1)과 상기 광변조기(2) 사이, 상기 빔확대기(4)와 상기 빔스프리터(6) 사이 및/또는 상기 빔스프리터(6)와 대물렌즈(8) 사이에 배치되어 입사광을 소정 각도로 반사키는 적어도 하나의 반사경을 포함한다.First, the optical pickup according to the present invention has the configuration as disclosed in FIG. 1 except for the reflecting mirror. That is, the recording and reproducing optical pickup according to the present invention includes a light source 1, an optical modulator 3 for modulating the light beam irradiated from the light source 1 into an optical signal, and the light beam so that the diameter of the light beam is expanded. And a beam expander 4 for enlarging the light beam modulated by the modulator 3, a beam splitter 6 for converting the traveling path of the light, and an objective lens 8 for focusing the incident light on the optical disk 9. . Further, the incident light is disposed between the light source 1 and the optical modulator 2, between the beam expander 4 and the beam splitter 6, and / or between the beam splitter 6 and the objective lens 8. At a predetermined angle, the reflection key includes at least one reflector.
제3도를 참조하면, 상기한 반사경(10)은 각각 반사면(11, 12)을 가지며, 그 반사면(11, 12)이 사이각 135°를 이루도록 2개의 거울을 일체로 구성한 것이다. 또한, 제4도에 도시된 바와 같이, 반사경(20)은 동일한 형태로서, 사이각 135°를 이루는 2개의 반사면(21, 22)을 가지며 그 2개의 반사면(21, 22)이 동일한 매질(23)에 형성되는 프리즘으로 구성된 것이다. 그리고 제5도에 도시된 바와 같이, 반사경(30)은 역시 프리즘으로서, 2개의 반사면(31, 32)을 가지며 그 2개의 반사면(31, 32)의 사잇각이 45°를 이루도록 구성한 것이다.Referring to FIG. 3, the reflecting mirror 10 has reflecting surfaces 11 and 12, respectively, and integrally constitutes two mirrors such that the reflecting surfaces 11 and 12 form an angle of 135 °. In addition, as shown in FIG. 4, the reflecting mirror 20 has the same shape, and has two reflecting surfaces 21 and 22 having an angle of 135 ° and the two reflecting surfaces 21 and 22 are the same medium. It consists of a prism formed in 23. As shown in FIG. 5, the reflector 30 is also a prism, and has two reflecting surfaces 31 and 32, and the angle between the two reflecting surfaces 31 and 32 is 45 degrees.
상기한 반사경(10, 20, 30)을 일측 반사면(11, 21, 31)으로 입사하는 입사광과 타측 반사면(12, 22, 32)으로부터 출사되는 반사광이 상호 90°를 이루도록 그 위치를 조정하면 된다.Adjust the position so that the incident light incident on the reflecting mirrors 10, 20, 30 to the one reflecting surface 11, 21, 31 and the reflected light emitted from the other reflecting surface 12, 22, 32 are 90 ° to each other. Just do it.
제6도 및 제7도는 각각 제4도 및 제5도에 도시된 반사경(20, 30)이 진동에 의하여 Δθ만큼 회전한 상태를 보인다. 이들 도면에서 그 일측 반사면(21, 31)에 대한 입사광의 입사각은 Δθ만큼 변화되고, 그 일측 반사면(21, 31)에서 반사되는 광의 반사각은 2Δθ만큼 변화된다. 그런데, 좌측 반사면(22, 32)은 그에 입사하는 광의 입사각 틸트량을 상쇄하는 방향으로 θ만큼 회전하게 되므로 그로부터 최종적으로 반사되는 반사광의 광축 틸트량은 상쇄되어 영(零)이 된다. 따라서 입사광에 대한 반사광의 출사각은 90°로 유지되며, 다만 각 반사면에서의 반사중심이 이동하여 광축 쉬프트만이 발생하게 된다. 그러나 광픽업에 있어서, 그 광축 쉬프트의 량은 다음에 설명되는 바와 같이 극소량이며 실질적으로 광픽업의 기록재생 및 제어특성에 거의 영향을 주지 않는다.6 and 7 show the reflectors 20 and 30 shown in FIGS. 4 and 5 rotated by Δθ by vibration. In these figures, the incident angle of incident light with respect to one side of the reflection surfaces 21 and 31 is changed by Δθ, and the angle of reflection of light reflected by the one side of the reflective surfaces 21 and 31 is changed by 2Δθ. However, since the left reflection surfaces 22 and 32 are rotated by θ in a direction to cancel the incident angle tilt amount of the light incident thereon, the optical axis tilt amount of the reflected light finally reflected therefrom is canceled out to be zero. Therefore, the exit angle of the reflected light with respect to the incident light is maintained at 90 degrees, but only the optical axis shift occurs because the center of reflection at each reflecting surface moves. However, in the optical pickup, the amount of optical axis shift is very small as described below, and substantially does not affect the recording reproduction and control characteristics of the optical pickup.
즉, 기록재생용 광픽업에 있어서, 광축 쉬프트의 허용범위는 일반적으로(쉬프트량)/(광빔의 직영)의 비로 나타내어 약 1/10이다. 여기서 광빔의 직경을 4㎜라 하면 허용 광축 쉬프트량은 0.4㎜가 된다. 전술한 135°의 사이각을 갖는 거울 또는 프리즘으로 구성된 반사경(10, 20)에 있어서, 광축 쉬프트량 Δd는 ΔdℓtanΔθ로서, 일측 반사면(11, 21)과 타측 반사면(12, 22) 사이의 광축간 거리를 ℓ=2㎜라 할 때, 허용 광축 쉬프트량 Δd=0.4㎜가 되는 Δθ값은 약 11°가 된다. 한편, 45°의 사잇각을 가즌 반사경(30)의 경우에 허용되는 Δθ값은 약 5.5°가 된다. 그러나 실질적으로 진동 또는 경시변화에 의한 미소회전량은 대략 1°이내이므로 그 광축쉬프트에 의한 영향은 염려되지 않는 것이다.That is, in the recording and reproducing optical pickup, the allowable range of the optical axis shift is generally about 1/10 represented by the ratio of (shift amount) / (directly from the light beam). If the diameter of the light beam is 4 mm, the allowable optical axis shift amount is 0.4 mm. In the reflecting mirrors 10 and 20 composed of a mirror or prism having the aforementioned angle of 135 °, the optical axis shift amount Δd is Δd As ΔtanΔθ, when the distance between the optical axes between the one reflective surfaces 11 and 21 and the other reflective surfaces 12 and 22 is ℓ = 2 mm, the Δθ value that becomes the allowable optical axis shift amount Δd = 0.4 mm is about 11 °. Becomes On the other hand, the value of Δθ that is allowed in the case of the pseudo reflector 30 with a 45 degree angle is about 5.5 °. However, since the microrotation amount due to vibration or change over time is substantially within 1 °, the effect of the optical axis shift is not concerned.
이상에서 설명한 바와 같이, 본 발명에 따른 광픽업은 상기한 구성의 반사경을 채용함으로써 광축 틸트에 의한 영향을 없애 기록재생 및 제어특성을 향상시키는데 매우 효과적이다. 또한, 성능을 향상시키는데 따른 추가적인 재료비의 부담이 없고 또한 그 설치작업이 수월한 바람직한 발명이다.As described above, the optical pickup according to the present invention is very effective in eliminating the influence of the optical axis tilt and improving the recording reproduction and control characteristics by employing the reflecting mirror having the above-described configuration. In addition, it is a preferred invention that there is no burden of additional material cost to improve the performance and the installation work is easy.
Claims (2)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019940018931A KR100230237B1 (en) | 1994-07-30 | 1994-07-30 | Optical pickup for recording and reproducing |
| JP7011315A JPH0862501A (en) | 1994-07-30 | 1995-01-27 | Reflecting mirror |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019940018931A KR100230237B1 (en) | 1994-07-30 | 1994-07-30 | Optical pickup for recording and reproducing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR960005487A KR960005487A (en) | 1996-02-23 |
| KR100230237B1 true KR100230237B1 (en) | 1999-11-15 |
Family
ID=19389566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019940018931A KR100230237B1 (en) | 1994-07-30 | 1994-07-30 | Optical pickup for recording and reproducing |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH0862501A (en) |
| KR (1) | KR100230237B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030023305A (en) * | 2001-09-13 | 2003-03-19 | 엘지전자 주식회사 | Optical pickup |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5622068B2 (en) | 2005-11-15 | 2014-11-12 | 株式会社ニコン | Surface position detection apparatus, exposure apparatus, and device manufacturing method |
| JP5622126B2 (en) * | 2005-11-15 | 2014-11-12 | 株式会社ニコン | Surface position detection apparatus, exposure apparatus, and device manufacturing method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02192043A (en) * | 1989-01-19 | 1990-07-27 | Fujitsu Ltd | Optical information processor |
-
1994
- 1994-07-30 KR KR1019940018931A patent/KR100230237B1/en not_active IP Right Cessation
-
1995
- 1995-01-27 JP JP7011315A patent/JPH0862501A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02192043A (en) * | 1989-01-19 | 1990-07-27 | Fujitsu Ltd | Optical information processor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030023305A (en) * | 2001-09-13 | 2003-03-19 | 엘지전자 주식회사 | Optical pickup |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0862501A (en) | 1996-03-08 |
| KR960005487A (en) | 1996-02-23 |
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