Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium
Reexamination Certificate
2000-01-27
2003-10-28
To, Doris H. (Department: 2655)
Dynamic information storage or retrieval
Specific detail of information handling portion of system
Radiation beam modification of or by storage medium
C369S112070, C369S112140, C369S112270
Reexamination Certificate
active
06639887
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical integrated apparatus or device used in an optical pickup apparatus for optically reproducing information recorded on a record medium, such as a CD (Compact Disc), a LVD (Laser Vision Disc) and the like, or optically recording the information onto the record medium.
2. Description of the Related Art
As disclosed in Japanese Patent Application Laid Open No.Hei-4-89634, as one type of the above-mentioned optical pickup apparatus, there is an apparatus which has a semiconductor laser as a light emitting device on a semiconductor substrate on which a phase film layer, a polarization film layer, a diffraction grating, a light guide path and a first light receiving portion are laminated, and that further has a second light receiving portion at an end of the light guide path.
In this optical pickup apparatus, when the laser light is irradiated from the semiconductor laser to the phase film layer at a predetermined depression angle, the laser light is transmitted through this phase film layer, is reflected on a surface of the polarization film layer, and is collected and projected onto an information surface of an optical disc. Then, the laser lights, which are diffracted and reflected on the information surface of the optical disc, are transmitted through the phase film layer and the polarization film layer, and are inputted to the diffraction grating. Most of the reflected laser lights become the transmitted lights which are transmitted through this diffraction grating and are sent below the substrate. The remainders thereof become the guided lights guided or propagated through the light guide path. The transmitted lights are received by the first light receiving portion. A tracking error signal, an RF (Radio Frequency) signal and the like are generated by this first light receiving portion. Also, the guided lights are received by the second light receiving portion formed at the end of the light guide path. A focus error signal is generated by this second light receiving portion.
According to this optical pickup apparatus, respective constitutional elements are integrated in a process of manufacturing the semiconductor substrate, which enables the whole apparatus to be compact, and also enables the improvement of an effective utilization efficiency of the light quantity.
However, in the above-mentioned conventional optical pickup apparatus, the second light receiving portion for generating the focus error signal has such a special positional relation that it is equipped vertically with respect to the light guide path and the first light receiving portion for generating the RF signal. This results in a problem that a general light receiving device cannot be used for the second light receiving portion.
As a result, in order to manufacture this optical pickup apparatus, it is necessary to newly manufacture the light receiving portion itself as a second light receiving portion. Moreover, the manufacturing process is relatively complex because of the above mentioned special positional relation as for the second light receiving portion. Thus, this also results in a problem of the increase of the manufacturing cost of the optical pickup apparatus.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an optical integrated apparatus for an optical pickup apparatus, which can achieve an integration by using a process of manufacturing a semiconductor substrate to thereby make the whole apparatus compact and improve the utilization efficiency of the light quantity, and can effectively utilize the existing manufacturing apparatus or method to thereby allow its easy manufacture and reduce its manufacturing cost.
The above object of the present invention can be achieved by a first optical integrated apparatus used in an optical pickup apparatus which irradiates a light emitted by a light emitting device to an optical information record medium, on which record information is recorded, and receives a reflection light reflected from the optical information record medium. The first optical integrated apparatus is provided with: a substrate; a light wave coupler for respectively generating a transmitted light and a guided light out of the reflection light; a light guide path for propagating the guided light; a first light receiving portion for receiving the transmitted light; and a second light receiving portion for receiving a radiant light which is generated out of the guided light and is directed toward the substrate due to a phase matching from the light guide path. The light wave coupler, the light guide path, the fist light receiving portion and the second light receiving portion are laminated on the substrate. The first light receiving portion and the second light receiving portion are formed in a same layer on the substrate.
According to the first optical integrated apparatus of the present invention, the light irradiated onto the optical information record medium, which is emitted from the light emitting device, is reflected by the optical information record medium. Then, the reflected light thereof is inputted to the light wave coupler of the optical integrated apparatus. The light wave coupler generates the guided light and the transmitted light out of the reflected light. The transmitted light is received by the first light receiving portion. On the other hand, the guided light is propagated through the light guide path and is irradiated from the light guide path by the phase matching toward the substrate so that the second light receiving portion receives it as the irradiated light. In this manner, the reflected light from the optical information record medium passes through the light wave coupler, the light guide path and the first or second light receiving portion. Since the light wave coupler, the light guide path and the first light receiving portion as well as the second light receiving portion are laminated on the substrate and since the first light receiving portion and the second light receiving portion are in the same layer, the first optical integrated apparatus can be easily manufactured by a planar technique such as a semiconductor manufacturing technique or an IC (Integrated Circuit) manufacturing process, and the manufacturing cost can be reduced. Also, the first optical integrated apparatus can be miniaturized while improving the light effective utilization efficiency.
In one aspect of the first optical integrated apparatus of the present invention, the first light receiving portion generates signals respectively corresponding to the record information and in-plane position information of the emitted light with respect to the optical information record medium, and the second light receiving portion generates a signal corresponding to focal point information of the emitted light on the optical information record medium.
According to this aspect, among the reflected light from the optical information record medium, the transmitted light generated by the light wave coupler is received by the first light receiving portion. The signal to read the record information and the signal to read the in-plane position information can be generated on the basis of the output of the first light receiving portion. On the other hand, among the reflected light from the optical information record medium, the guided light generated by the light wave coupler is propagated through the light guide path and is received by the second light receiving portion as the irradiated light toward the substrate from the light guide path by phase matching. Then, on the basis of the output of the second light receiving portion, the signal to read the focal position information is generated. As mentioned above, since the signal to read the record information and the signal to read the in-plane position information can be generated on the basis of the transmitted light having the enough intensity, those signals can be generated as having good qualities. Further, since the signal to rea
Patel Gautam R.
Pioneer Corporation
To Doris H.
Young & Thompson
LandOfFree
Optical apparatus with laser light receiver and focus error... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical apparatus with laser light receiver and focus error..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical apparatus with laser light receiver and focus error... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3140174