CN1841530A - Optical reading device and its optical reading head - Google Patents

Abstract

The invention relates to an optical reading device and an optical reading head thereof, wherein the optical reading head is used for reading an optical information storage medium, the optical information storage medium comprises a penetrating type recording layer, the optical reading head comprises a light source, a first polarization element, a first objective lens, a second objective lens and an image detection unit, the light source emits a light beam, the first polarization element polarizes the light beam into linearly polarized light, the first objective lens focuses the linearly polarized light on the penetrating type recording layer and penetrates through the optical information storage medium to form penetrating light, and the image detection unit receives the penetrating light passing through the second objective lens and converts the penetrating light into an electric signal corresponding to a data signal.

Description

Optical reading device and its optical reading head

technical field

The invention relates to an optical reading head, in particular to an optical reading device capable of reading a penetrating optical information storage medium and its optical reading head.

Background technique

With the advent of the information and multimedia era, consumers' demand for storage media capacity has increased rapidly. Among them, because the optical information storage medium can store a large amount of data, and has the characteristics of portability and long-term storage of data, it is quite popular to use the optical information storage medium to access data.

Today's common optical information storage media include compact disc (CD, Compact Disc) and digital audio-visual disc (DVD, Digital Versatile Disc). Both structures include a recording layer and a reflective layer. The recording layer uses recording grooves to record data. , when an optical reading device reads data, the optical reading device emits a laser beam focused on the recording layer, and the reflective layer of the optical information storage medium provides an image detection that reflects the laser light and returns it to the optical reading device Components (photodetector) to convert laser light into electrical signals that can be identified and processed to complete data reading.

Based on the above, the existing known optical information storage media uses laser light to irradiate the recording groove of the recording layer, and the laser light is reflected by different degrees to convert it into a well-known 0, 1 signal. However, the above-mentioned For the mechanism of obtaining the information of the optical information storage medium by reflecting the laser light, since the reflected laser light needs to pass through the multi-layer structure of the optical information storage medium on the way to the image detection element, the laser light passing through the multi-layer medium will be absorbed and then The weakening of the reading signal affects the interpretation of the data. Therefore, in order to ensure a better reading signal, it is improved by increasing the power of the emitting laser. However, this will reduce the optical reading of the emitting laser under long-term use. Therefore, the optical information storage media industry is committed to developing optical information storage media that can obtain information without using the mechanism of laser reflection. For example, the material of the recording layer of the optical information storage medium can be changed. , to use, for example, a penetrating reading method to modulate the laser light to achieve the purpose of obtaining 0 and 1 signals.

However, in response to the research and development of the above-mentioned transmissive optical information storage medium that does not need to use the mechanism of laser reflection to obtain information, the corresponding optical reading device and the optical reading head therein also need to be produced accordingly.

It can be seen that the above-mentioned existing optical reading device and its optical reading head obviously still have inconveniences and defects in structure and use, and need to be further improved urgently. In order to solve the problems existing in the optical reading device and its optical reading head, the relevant manufacturers have tried their best to find a solution, but for a long time, no suitable design has been developed, and the general product has no suitable structure. Being able to solve the above-mentioned problems is obviously a problem that relevant industry players are eager to solve.

In view of the defects in the above-mentioned existing optical reading device and its optical reading head, the present inventor actively researches and innovates based on years of rich practical experience and professional knowledge engaged in the design and manufacture of such products, and in cooperation with the application of academic theories. It is hoped to create an optical reading device and its optical reading head with a new structure, which can improve the general existing optical reading device and its optical reading head, making it more practical. Through continuous research, design, and after repeated trial samples and improvements, the present invention with practical value is finally created.

Contents of the invention

The object of the present invention is to provide an optical reading device capable of reading a transmissive optical information storage medium and an optical reading head thereof.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. An optical pickup head proposed according to the present invention is used to read an optical information storage medium, the optical information storage medium includes a transmissive recording layer, the optical pickup head includes: a light source, which emits A light beam; a first polarizing element, which polarizes the light beam into a linearly polarized light; a first objective lens, which focuses the linearly polarized light on the transmissive recording layer, and passes through the light The information storage medium forms a penetrating light; a second objective lens; and an image detection unit, which receives the penetrating light passing through the second objective lens and converts the penetrating light into an electrical signal corresponding to a data signal. Signal.

The purpose of the present invention and its technical problems can also be further realized by adopting the following technical measures.

The aforementioned optical pickup head further includes: a collimating lens disposed between the light source and the first polarizing element.

The aforementioned optical pickup head, wherein the image detection unit includes a second polarizing element and a detecting element, the second polarizing element is arranged on the transmitted light path and before the detecting element .

The aforementioned optical pickup head further includes a third objective lens disposed between the second polarizing element and the detecting element.

In the aforementioned optical pickup head, the numerical aperture of the first objective lens is about 0.60.

In the aforementioned optical pickup head, the numerical aperture of the first objective lens is about 0.40 to 0.50.

The purpose of the present invention and the solution to its technical problems are also achieved by the following technical solutions. An optical reading device proposed according to the present invention is used to read an optical information storage medium, the optical information storage medium includes a transmissive recording layer, and the optical reading device includes: an optical reading head , which includes a light source, a first polarizing element, a first objective lens, a second objective lens and an image detection unit, wherein the light source emits a light beam, and the first polarizing element polarizes the light beam It is a linearly polarized light, the first objective lens focuses the linearly polarized light on the transmissive recording layer, and passes through the optical information storage medium to form a transmitted light, and the image detection unit receives and passes through the second The penetrating light of the objective lens, and converting the penetrating light into an electrical signal corresponding to the data signal; a control unit, which changes the relative position of the optical pickup head and the optical information storage medium; and a signal processing The unit is used to process the electrical signal sent by the optical pickup head to obtain the information of the optical information storage medium.

The purpose of the present invention and its technical problems can also be further realized by adopting the following technical measures.

The aforementioned optical reading device further includes a collimating lens disposed between the light source and the first polarizing element.

The aforementioned optical reading device, wherein the image detection unit includes a second polarizing element and a detecting element, the second polarizing element is arranged on the transmitted light path and before the detecting element .

The aforementioned optical reading device further includes a third objective lens disposed between the second polarizing element and the detecting element.

In the aforementioned optical reading device, the numerical aperture of the first objective lens is about 0.60.

In the aforementioned optical reading device, the numerical aperture of the first objective lens is about 0.40 to 0.50.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. It can be seen from the above technical solutions that the optical reading device and its optical reading head of the present invention have at least the following advantages:

According to the optical reading device and its optical reading head in a preferred embodiment of the present invention, the optical reading head uses a first polarizing element located on one side of the optical information storage medium to polarize the light beam emitted by the light source into linear Polarized light, when the linearly polarized light passes through the optical information storage medium with light-modulating substances, different read signals are generated by modulating (for example: rotating) the linearly polarized light through the light-modulating substances, and then by The image detection element located on the other side of the optical information storage medium converts the read signal with information into an electrical signal that can be recognized and processed. This optical read head is applied to an optical read device, and the control unit is used for information reading. The position control of the pickup and the signal processing unit process the signal sent by the optical pickup head to complete the reading of the data. With this invention, the problem of the weakening of the read signal when reading the reflective optical information storage medium in the prior art can be effectively improved and obtained. A better read signal and, in turn, can increase the lifetime of the optical read head.

In summary, the optical reading device and its optical reading head of the special structure of the present invention have the above-mentioned many advantages and practical value, and no similar structural design has been published or used in similar devices and products. It is indeed an innovation, and it has great improvements in both the structure and function of the device and the product, and has made great progress in technology, and has produced easy-to-use and practical effects, and is better than the existing optical reading device. And its optical reading head has multiple enhanced effects, so it is more suitable for practical use, and has wide application value in the industry. It is a novel, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are specifically cited below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram showing an optical pickup head according to a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram showing an optical pickup head according to another preferred embodiment of the present invention.

FIG. 3 is a schematic diagram showing an optical reading device according to a preferred embodiment of the present invention.

1: Optical reading device 10: Optical reading head

11: Light source 12: The first polarizing element

13: The first objective lens 14: Image detection unit

141: Second polarization element 142: Detection element

15: Second objective lens 16: Collimating lens

17: Third objective lens 20: Storage medium

201: Penetrating recording layer 30: Control unit

301: Motor 302: Driving element

40: Signal processing unit

Detailed ways

In order to further explain the technical means and effects that the present invention adopts to achieve the intended purpose of the invention, below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation methods, Structure, characteristic and effect thereof are as follows in detail.

The optical pickup device and its optical pickup head according to preferred embodiments of the present invention will be described below with reference to related drawings, wherein the same elements will be described with the same reference symbols.

Please refer to shown in Fig. 1, the optical pick-up head 10 according to the preferred embodiment of the present invention comprises a light source 11, a first polarization element 12, a first objective lens 13, a second objective lens 15 and an image detection unit 14 , for reading an optical information storage medium 20 , especially an optical information storage medium 20 including a transmissive recording layer 201 .

The light source 11 emits a light beam as the incident light beam. In this embodiment, the light source 11 can be a laser light emitting diode (Laser Diode). The wavelength of the light beam can be selected according to actual needs such as 780nm or 650nm to read the optical information storage medium 20.

The first polarizing element 12 can be, for example, a polarizer, which is used to polarize the light beam into linearly polarized light, that is, to fix the light to vibrate on a plane.

The first objective lens 13 is arranged on one side of the optical information storage medium 20 and is located on the path of the linearly polarized light, for focusing the linearly polarized light on the transmissive recording layer 201 of the optical information storage medium 20, for example, The transmissive recording layer 201 may include a light-modulating substance such as an optically active substance to rotate the vibration plane of light, and the track of information recorded by the transmissive recording layer 201 is different in depth, causing the light focused on it to be The angle of rotation also differs from the mechanism to produce a distinguishable read signal. Wherein, the numerical aperture (Numerical Aperture) of the first objective lens 13 can be about 0.60 or between about 0.40 to 0.50 to determine the size of the read light spot, so depending on actual needs, for example, when the read optical information is stored The first objective lens 13 with a numerical aperture of 0.60 can be selected when the medium 20 is a DVD groove specification, and the first objective lens 13 with a numerical aperture of 0.40 to 0.50 can be selected when the optical information storage medium 20 to be read is a CD groove specification , this is just an example, and of course, the first objective lens 13 with different numerical apertures can also be selected according to the groove specifications of different optical information storage media 20 .

As shown in FIG. 1 , the linearly polarized light used for reading information is transmitted through the optical information storage medium 20 to form a transmitted light, which is focused by the second objective lens 15 positioned on the other side of the optical information storage medium 20 and detected by the image detector. Out unit 14 receives.

The image detection unit 14 includes a second polarizing element 141 and a detecting element 142. The second polarizing element 141 is arranged on a path of a penetrating light passing through the optical information storage medium 20 and is located at the detecting element. Before 142, the second polarizing element 141 receives the transmitted light with the data signal, and separates the intensity of a certain vector of the light wave, and then converts it into an identifiable process and corresponding The electric signal in the data signal is used to obtain the recording data of the optical information storage medium 20 .

Also, referring to FIG. 2, the optical pickup head 10 according to a preferred embodiment of the present invention further includes a collimator lens 16 (Collimator lens) disposed between the light source 11 and the first polarizing element 12, in order to The light beam emitted by the light source 11 is parallel processed into a parallel light beam.

Based on the above, the optical pickup head 10 of the preferred embodiment of the present invention may further include a third objective lens 17 disposed between the second polarizing element 141 and the detecting element 142 in the image detecting unit 14 .

In addition, please refer to FIG. 3, an optical reading device 1 according to a preferred embodiment of the present invention includes an optical reading head 10, a control unit 30 and a signal processing unit 40. This optical reading device 1 is an application When reading an optical information storage medium 20 , especially an optical information storage medium 20 including a transmissive recording layer 201 .

The structure of the optical pickup head 10 is applied as described above, so it is not repeated here.

The control unit 30 is used to change the relative position of the optical pickup head 10 and the optical information storage medium 20. The control unit 30 may include a motor 301 and a drive element 302. The motor 301 is used to rotate the optical information storage medium 20, and the drive element 302 is used to move the optical pick-up head 10 to control the position of focusing and tracking.

The signal processing unit 40 may include a circuit board for processing the electrical signal transmitted from the optical pickup head 10 to obtain the information of the optical information storage medium 20 .

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the structure and technical content disclosed above to make some changes or modifications to equivalent embodiments with equivalent changes, but if they do not depart from the technical solution of the present invention, Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

Claims (12)

1. An optical pickup head, which is used to read an optical information storage medium, the optical information storage medium includes a transmissive recording layer, characterized in that the optical pickup head includes: a light source emitting a beam of light; a first polarizing element, which polarizes the light beam into linearly polarized light; A first objective lens, which focuses the linearly polarized light on the transmissive recording layer, and passes through the optical information storage medium to form a transmitted light; a second objective lens; and An image detection unit receives the penetrating light passing through the second objective lens, and converts the penetrating light into an electrical signal corresponding to the data signal. 2. The optical pickup head according to claim 1, further comprising: A collimating lens is arranged between the light source and the first polarizing element. 3. The optical pickup head according to claim 1, wherein the image detection unit comprises a second polarizing element and a detecting element, the second polarizing element is arranged on the penetrating on the light path and before the detection element. 4. The optical pickup head according to claim 3, further comprising: A third objective lens is arranged between the second polarization element and the detection element. 5. The optical pickup head according to claim 1, wherein the numerical aperture of said first objective lens is about 0.60. 6. The optical pickup head according to claim 1, wherein the numerical aperture of said first objective lens is about 0.40 to 0.50. 7. An optical reading device, which is used to read an optical information storage medium, the optical information storage medium includes a transmissive recording layer, characterized in that the optical reading device includes: An optical reading head, which includes a light source, a first polarizing element, a first objective lens, a second objective lens and an image detection unit, wherein the light source emits a light beam, and the first polarizing element is to The light beam is polarized into a linearly polarized light, the first objective lens focuses the linearly polarized light on the transmissive recording layer, and passes through the optical information storage medium to form a transmitted light, and the image detection unit is receiving the transmitted light passing through the second objective lens, and converting the transmitted light into an electrical signal corresponding to a data signal; a control unit, which changes the relative position of the optical pickup head and the optical information storage medium; and A signal processing unit is used to process the electrical signal sent by the optical pickup head to obtain the information of the optical information storage medium. 8. The optical reading device according to claim 7, further comprising: A collimating lens is arranged between the light source and the first polarizing element. 9. The optical reading device according to claim 7, wherein the image detection unit comprises a second polarizing element and a detecting element, and the second polarizing element is arranged on the penetrating on the light path and before the detection element. 10. The optical reading device according to claim 9, further comprising a third objective lens disposed between the second polarizing element and the detecting element. 11. The optical pickup device according to claim 7, wherein the numerical aperture of said first objective lens is about 0.60. 12. The optical pickup device according to claim 7, wherein the numerical aperture of said first objective lens is about 0.40 to 0.50.

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