CN1719525A - Optical read/write system - Google Patents

Abstract

An optical reading/writing system includes a first optical transceiver unit, a second optical transceiver unit, a third optical transceiver unit, a prism group, a reflective prism, a collimator lens and an objective lens. The prism group has a first prism located in the common optical path of the first and second incident light beams, a second prism located in the optical path of the third incident light beam and a second prism located in the common optical path of the first, second and third incident light beams Prism. The reflective prism has a light incident surface and a light exit surface. The light incident surface is adjacent to the light exit surface and forms a certain angle. The light signal perpendicular to the light incident surface of the reflective prism is reflected between the surfaces of the reflective prism and can be perpendicular to the The light-emitting surface of the reflective prism emits light. The collimating lens and the objective lens have optical parameters corresponding to the first wavelength, and are located in an optical path shared by the first, second and third incident light beams.

Description

Optical read/write system

【Technical field】

The invention relates to an optical disc recording/reproducing system, in particular to an optical reading/writing system for compatible optical discs of different specifications.

【Background technique】

The optical read/write system used in the recording/reproducing device mainly utilizes a series of optical components to focus the laser light of a specific wavelength emitted by the laser into a spot and focus it on the optical disc to realize the read/write operation on the optical disc. With the continuous evolution of optical disc specifications from CD, DVD to HD-DVD, the information tracks of optical discs are made more dense, which requires the smaller the light spot for reading/writing information on optical discs. The size of the spot is related to the wavelength of the laser and the numerical aperture (NA) of the objective lens. The size of the spot is proportional to the wavelength of the laser and inversely proportional to the numerical aperture (NA) of the objective lens. In this way, the evolution of optical disc specifications to high density leads to the continuous reduction of the wavelength of the laser light and the continuous increase of the numerical aperture (NA) of the objective lens. The changes of wavelength and numerical aperture (NA) with disc specifications are shown in the table below: Disc Specifications cd DVD HD-DVD wavelength 780nm 650nm 405nm Numerical aperture (NA) 0.45 0.6 0.65 or 0.8

Due to the different optical parameters of different optical disc specifications, the compatibility problem of each specification becomes prominent. To read/write information on an optical disc of a specific specification, it is necessary to use an optical component that meets the specification of the optical disc, otherwise, it will cause the possibility of misreading/writing. However, it is obviously unwise to design a corresponding optical read/write system for each specification in order to realize the read/write operation to multiple specifications of optical discs in a set of optical read/write devices. The excessive volume of the device makes the optical system complicated and increases the cost. In existing optical read/write devices, such as hybrid HD-DVD and DVD optical read/write devices, it has a HD-DVD laser and a DVD laser, respectively emitting blue light with a wavelength of about 405nm and red light with a wavelength of 650nm, and After entering the respective diffraction components, they pass through optical components such as a shared dichroic prism, collimating lens, reflector, and objective lens, and then converge to the optical disc for reading/writing information. This kind of optical read/write device can reduce its volume to a certain extent by sharing part of the optical components. However, the spatial distance between the laser and the collimator lens is just an important factor affecting the volume of the optical read/write device. Although the number of optical components in the existing optical read/write device has been reduced, the distance between the laser and the collimator lens has not been shortened. The spatial distance between them, therefore, its reduction in the size of the optical read/write device is limited.

【Content of invention】

The technical problem to be solved by the present invention is to provide an optical reading/writing system used in recording/reproducing devices of different optical disc specifications, which can reduce the volume of the optical reading/writing device.

The invention provides an optical reading/writing system, which includes a first optical transceiver unit, a second optical transceiver unit, a third optical transceiver unit, a prism group, a reflective prism, a collimating lens and an objective lens. The first optical transceiver unit has a first light source for emitting a first incident light beam with a first wavelength. The second optical transceiver unit has a second light source for emitting a second incident light beam with a second wavelength, and the second wavelength is greater than the first wavelength. The third optical transceiver unit has a third light source for emitting a third incident light beam with a third wavelength, and the third wavelength is greater than the second wavelength. The prism group has a first prism located in the common optical path of the first and second incident light beams, a second prism located in the optical path of the third incident light beam and a second prism located in the common optical path of the first, second and third incident light beams Prism. The first prism has a first light incident surface, and the first light incident surface has a first light incident area for the first incident light beam to pass through and a second light incident area for the second incident light beam to pass through, and the second light incident area The area is an aspheric structure surface, the first prism is used to transmit the first and second incident light beams, and output them to the third prism, the second prism is used to transmit the third incident light beam, and output it to the third prism, the second prism is used to transmit the third incident light beam, and output it to the third prism, The second prism also has an aspherical end surface. The third prism is used to output the first, second and third incident light beams from different optical paths from the same position. The reflective prism has a light incident surface and a light exit surface, and the light incident surface is adjacent to the light exit surface at a certain angle, and the optical signal perpendicular to the light incident surface of the reflective prism is reflected between the surfaces of the reflective prism. emerge from the light-emitting surface of the reflective prism. The collimating lens has an optical parameter corresponding to the first wavelength, and is located in an optical path shared by the first, second and third incident light beams. The objective lens also has optical parameters corresponding to the first wavelength, and is located in the optical path shared by the first, second and third incident light beams.

Compared with the prior art, the optical read/write system of the present invention uses three optical transceiver units and a prism group with an aspheric surface structure to effectively eliminate aberrations, and then realize CD, DVD, HD-DVD and other various specification discs. Reading and writing of information for better effect. The optical paths of the first, second, and third incident light beams share part of the optical components, thus reducing the number of optical components required by the optical read/write system. The spatial distance between the first, second and third optical transceiver units and the collimating lens, and the application of the reflective prism can omit the reflector, thereby effectively reducing the volume of the device using the optical read/write system.

【Description of drawings】

FIG. 1 is a schematic diagram of an optical read/write system according to a first embodiment of the present invention.

FIG. 2 is a top view of the prism group in FIG. 1 .

FIG. 3 is a front view of the reflective prism in FIG. 1 .

FIG. 4 is a plan view of the wavelength selective sheet of FIG. 1 .

FIG. 5 is a cross-sectional view of the wavelength selection sheet taken along line V-V in FIG. 4 .

FIG. 6 is a schematic diagram of an optical read/write system according to a second embodiment of the present invention.

FIG. 7 is a front view of the reflective prism in FIG. 6 .

【Detailed ways】

Please refer to FIG. 1 , which is a schematic diagram of an optical read/write system 100 according to a first embodiment of the present invention. The optical reading/writing system 100 of the present invention is suitable for recording/reproducing devices of different optical disc specifications. This embodiment takes an optical reading/writing system suitable for HD-DVD recording/reproducing devices as an example. Optical read/write system 100 comprises a first optical transceiver unit 11, a second optical transceiver unit 12, a third optical transceiver unit 13, a first diffraction assembly 21, a second diffraction assembly 22, a third Diffraction component 23 , a prism group 3 , a reflective prism 4 , a collimator lens 5 , a wavelength selection plate 6 and an objective lens 7 . Among them, the first optical transceiver unit 11, the second optical transceiver unit 12, the third optical transceiver unit 13, the first diffraction component 21, the second diffraction component 22, the third diffraction component 23, and the prism group 3 can be integrated and packaged .

The first, second and third optical transceiver units 11, 12 and 13 are arranged in parallel and juxtaposed. The first optical transceiver unit 11 has a first light source 11a and a first detector 11b. The first light source 11a emits a first incident beam having a first wavelength. The first detector 11b detects the first reflected beam returning from the optical disc. The second optical transceiver unit 12 includes a second light source 12a and a second detector 12b. The second light source 12a emits a second incident light beam having a second wavelength. The second detector 12b detects the second reflected light beam returning from the optical disc. The third optical transceiver unit 13 includes a third light source 13a and a third detector 13b. The third light source 13a emits a third incident beam having a third wavelength. The third detector 13b detects the third reflected light beam returning from the optical disc. In this embodiment, the first, second and third wavelengths are blue light with a wavelength of 405nm for readable/writable HD-DVD discs, red light with a wavelength of 650nm for readable/writable DVD discs and 780nm Near-infrared light that can read/write CD format discs.

The first diffraction component 21, the second diffraction component 22 and the third diffraction component 23 are respectively facing the first, second and third light sources 11a of the first, second and third transceiver units 11, 12 and 13 , 12a, 13a settings.

Please refer to FIG. 2 , which is a top view of the prism group 3 of the optical read/write system 100 of the present invention. The prism group 3 includes a first prism 31 , a second prism 32 , and a third prism 33 , and the first and second prisms 31 and 32 are located on the same side of the third prism 33 . The first, second and third prisms 31 , 32 and 33 are all approximately quadrangular prism structures. The first prism 31 has a first light incident surface 310 and a first light exit surface 311, the first light incident surface 310 is divided into first and second light incident areas 310a, 310b, wherein the second light incident area 310b is an aspherical structure , can correct redundant spherical aberration of DVD optical path. One end of the first prism 31 has a first reflective surface 312 at an angle of 45 degrees with the first incident surface 310, and the other end has a first light path conversion interface 313 parallel to the first reflective surface 312, which is aimed at different The wavelength of incident light has different reflection or transmission functions. The second prism 32 has a second light incident surface 320 and a second light exit surface 321. The second light incident surface 320 is an aspherical structure, which can correct redundant spherical aberration of the CD optical path. The third light incident surface 330 of the third prism 33 is parallel to the third light exit surface 331, one end of the third prism 33 has a third reflective surface 332 at an angle of 45 degrees with the third light incident surface 330, and the other end has a third reflection surface 332 with the third light incident surface 330. The third reflective surface 332 is parallel to the second light path conversion interface 333 , which has different reflective or transmissive functions for incident light of different wavelengths.

Please refer to FIG. 3 , which is a top view of the reflective prism 4 of the optical read/write system of the present invention. The reflecting prism 4 and the collimating lens 5 have a combined surface (the fourth light-emitting surface 42 described below). The reflective prism 4 is a pentagonal prism structure, and its five sides connected successively form a fourth light incident surface 40, a fourth light exit surface 42, a fourth reflective surface 44, a fourth side surface 46 and a fifth reflective surface 48, wherein The fourth light-incident surface 40 and the fourth light-exit surface 42 (that is, the above-mentioned joint surface) are arranged perpendicular to each other. The included angles between the surfaces 44, the fourth reflective surface 44, the fourth side surface 46, the fourth side surface 46, the fifth reflective surface 48, and the fourth incident surface 40 and the fifth reflective surface 48 are all 112.5 degrees. The optical signal that satisfies the requirement of being vertically incident on the fourth light-incident surface 40 can be emitted perpendicular to the fourth light-emitting surface 42 after being reflected by the surfaces of the reflective prism 4, so that the transmission direction of the incident light beam is changed after passing through the reflective prism 4 90 degrees.

Please refer to Figure 4 and Figure 5 together. The wavelength selection sheet 6 is located between the objective lens 7 and the collimator lens 5. The wavelength selection sheet 6 has three regions from the inside to the outside, namely the inner circle region A, the middle ring region B and the outer ring region C. The inner circle region A can allow the shortest The light beams of the first wavelength, the shorter second wavelength, and the longer third wavelength pass through, the middle ring area B can allow the light beams of the shortest first wavelength and the shortest second wavelength to pass through, and the outer ring area C only allows the shortest first wavelength. wavelengths of light beams pass through.

Please refer to FIG. 1 again. When reading/writing an HD-DVD disc, the first incident light beam emitted by the first light source 11a of the first transceiver unit 11 passes through the first diffraction component 21 and passes through the first incident beam of the first prism 31. The first light incident region 310 a of the light surface 310 is incident to the first light path conversion interface 313 . Since the first light path conversion interface 313 is designed to transmit the first incident light beam with the shortest first wavelength and reflect the second incident light beam with the longer second wavelength, the first incident light beam passes through the first light path conversion interface 313 transmitted, and then emitted from the first light-emitting surface 311. The first incident light beam emitted from the first light emitting surface 311 enters the second light path conversion interface 333 from the third light incident surface 330 of the third prism 33 . Since the second optical path conversion interface 333 is designed to transmit the first incident light beam of the shortest first wavelength and the second incident light beam of the shorter second wavelength, and reflect the third incident light beam of the longer third wavelength, , the first incident light beam is transmitted through the second light path conversion interface 333 , and then emerges from the third light output surface 331 .

The first incident beam emitted from the third light-emitting surface 331 of the third prism 33 is reflected after being incident on the fourth reflective surface 44 coated with a reflective film through the fourth incident surface 40 of the reflective prism 4, and the first incident light beam after reflection The light beam is reflected again on the fifth reflective surface 48 coated with reflective film. The second-reflected first incident light beam enters the fourth light-emitting surface 42 , and then converges for the first time through the collimator lens 5 (designed for the first incident light beam with the shortest first wavelength) before exiting to the wavelength selection plate 6 .

The first incident light beam is converged for the first time and exits to the wavelength selection plate 6 . The wavelength selection sheet 6 has an inner circle area A, a middle ring area B and an outer ring area C. Since the inner circle area A and the middle ring area B can allow light beams with the shortest first wavelength and a shorter second wavelength to pass through, the outer ring area C Only light beams of the shortest first wavelength are allowed to pass. Therefore, the first incident light beam passes through all regions of the wavelength selective plate 6 and is converged into a light spot by the objective lens 7 for reading/writing information on an HD-DVD disc (not shown). The first reflected light beam reflected from the surface of the optical disk returns through the objective lens 7, and its returning light path is substantially the same as the incident light path. The difference is that the first reflected light beam is refracted by the first diffraction component 21 after passing through the first diffraction component 21, and the refracted first reflected light beam is projected onto the first detector 11b on the first transceiver unit 11. A detector 11b converts the optical signal into an electrical signal and outputs it to related circuits.

The optical parameters of various optical components included in the optical paths of the first incident light beam and the first reflected light beam are designed according to the HD-DVD standard. Simultaneously, reflective prism 4 shortens the spatial distance between transceiver unit 11 and collimating lens 5 under the condition that the total optical path of guaranteeing the light path is constant, and utilizes reflective prism 4 to replace reflective surface mirror, these improvements effectively reduce the use of The volume of the device of the optical read/write system 100 .

When reading/writing a DVD disc, the second incident light beam emitted by the second light source 12a of the second transceiver unit 12 passes through the second diffraction component 22 and passes through the second light incident area of the first light incident surface 310 of the first prism 31 310b is incident on the first reflective surface 312 and converged by the second incident region 310b having an aspheric structure for the first time. The first reflective surface 312 reflects the second incident light beam to the first light path conversion interface 313 . Since the first optical path conversion interface 313 is designed to transmit the first incident light beam with the shortest first wavelength and reflect the second incident light beam with a longer second wavelength, the second incident light beam is transmitted by the first optical path conversion interface 313 After reflection, it emits from the first light-emitting surface 311 . At the same time, since the first reflective surface 312 and the first optical path conversion interface 313 are parallel to each other, the outgoing direction of the second incident light beam emitted from the first light exit surface 311 is the same as the direction of the second incident light beam incident from the second light incident area 310b. The direction of incidence is the same. The emitted second incident light beam enters the second light path conversion interface 333 from the third light incident surface 330 of the third prism 33 . Since the second optical path conversion interface 333 is designed to transmit the first incident light beam of the shortest first wavelength and the second incident light beam of the shorter second wavelength, and reflect the third incident light beam of the longer third wavelength, , the second incident light beam is transmitted through the second light path conversion interface 333 , and then emerges from the third light output surface 331 .

The second incident light beam emitted from the third prism 33 is reflected after being incident on the fourth reflective surface 44 coated with a reflective film through the fourth incident surface 40 of the reflective prism 4, and the second incident light beam after reflection is reflected on the fifth reflective surface. 48 was reflected again. The second incident light beam reflected twice enters the fourth light exit surface 42 , and then converges for the second time through the collimator lens 5 (designed for the first incident light beam with the first wavelength) before exiting to the wavelength selection plate 6 .

The second incident light beam is converged for the second time and then exits to the wavelength selection plate 6 . The wavelength selection sheet 6 has an inner circle area A, a middle ring area B and an outer ring area C. Since the inner circle area A and the middle ring area B can allow light beams with the shortest first wavelength and a shorter second wavelength to pass through, the outer ring area C Only light beams of the shortest first wavelength are allowed to pass. Therefore, the second incident light beam can only pass through the inner circle area A and the middle ring area B, while the outer peripheral part of the second incident light beam is blocked by the outer circle area C and cannot pass through. The second incident light beam passing through the inner circle area A and the middle ring area B satisfies the numerical aperture of the DVD standard, and is converged by the objective lens 7 for the third time into a light spot for reading/writing information on the DVD disc (not shown). The second reflected light beam reflected from the surface of the optical disk returns through the objective lens 7, and its returning light path is substantially the same as the incident light path. The difference is that the second reflected light beam is refracted by the second diffraction component 22 after passing through the second diffraction component 22, and the refracted second reflected light beam is projected onto the second detector 12b on the second transceiver unit 12. The second detector 12b converts the optical signal into an electrical signal and outputs it to a related circuit.

Although the optical parameters of the shared part of the optical components in the optical path of the second incident light beam and the first incident light beam are all designed with reference to the HD-DVD standard, the second incident light beam passes through the second incident light beam of the first light incident surface of the first prism 31 The light zone 310b, the collimating lens 5, and the objective lens 7 are converged three times, and the wavelength selection plate 6 is used to make the second incident light beam meet the numerical aperture of the DVD specification, so that the mismatch between the collimating lens and the objective lens in the existing optical system can be effectively eliminated. aberrations caused. Simultaneously, utilize reflective prism 4 to shorten the spatial distance between transceiver unit 12 and collimating lens 5 under the condition that the total optical path of the optical path is guaranteed to be constant, and utilize reflective prism 4 to replace reflective surface mirror, these improvements effectively reduce The volume of the device using the optical read/write system 100 .

When reading/writing a CD disc, the third incident light beam emitted by the third light source 13a of the third transceiver unit 13 passes through the third diffraction component 23 and then enters from the second light incident surface 320 of the second prism 32, and is transmitted by a non- The second light incident surface 320 of the spherical structure converges for the first time. The third incident light beam after the first convergence is incident from the third light incident surface 330 of the third prism 33 , and is reflected to the second light path conversion interface 333 on the third reflective surface 332 of the third prism 33 . The second optical path conversion interface 333 has selectivity, which transmits the first incident light beam with the shortest first wavelength and the second incident light beam with the shorter second wavelength, and transmits the third incident light beam with the third wavelength with the longer wavelength. Incident beam reflections. At the same time, since the third reflection surface 332 is parallel to the second light path conversion interface 333, the third reflected light beam emerges from the third light exit surface 331 after being reflected twice, and the direction of exit is the same as that incident from the third light incident surface 330. The same direction.

The third incident light beam converged by the second prism 32 for the first time and emerges from the third prism 33 passes through the reflective prism 4 in the same optical path as the first incident light beam, and is converged by the collimating lens 5 of the reflective prism 4 for the second time. Since the optical parameters of the collimator lens 5 are designed for the first incident light beam with the shortest wavelength (first wavelength), it can only converge the third incident light beam into an approximately parallel light beam for the second time. The approximately parallel third incident light beam is reflected by the reflective prism 4 to change the direction of the optical path and then enters the wavelength selection sheet 6. Because the inner circle area A of the wavelength selection sheet 6 has the shortest wavelength (first wavelength) and shorter wavelength (second wavelength) Incident light beams with a longer wavelength (third wavelength) can both pass through, incident light beams with the first and second wavelengths in the middle ring area B can pass through, and the outer ring area C only allows incident light with the shortest first wavelength to pass through. Therefore, the third incident light beam can only pass through the inner circle area A, while the outer peripheral part of the third incident light beam is blocked by the middle ring area B and the outer ring area C and cannot pass through. The third incident light beam passing through the inner circle area A satisfies the smaller numerical aperture of the CD specification, and it is incident on the objective lens 7 and converged by the objective lens 7 to form a light spot for the third time to read/write information on the CD disc. The third reflected light beam reflected from the surface of the CD disc returns through the objective lens 7, and its returning light path is substantially the same as the incident light path. The difference is that the third reflected light beam is refracted by the third diffraction component 23 after passing through the third diffraction component 23, and the refracted third reflected light beam is projected onto the third detector 13b on the third transceiver unit 13. The three detectors 13b convert optical signals into electrical signals and output them to related circuits.

Although the optical parameters of the shared part of the optical components in the optical path of the third incident light beam and the first incident light beam are designed with reference to the HD-DVD specification, the third incident light beam passes through the collimating lens 5 of the second prism 32, the reflective prism 4 and The objective lens 7 converges three times, and the wavelength selective plate 6 is used to make the third incident light beam meet the numerical aperture of the CD specification, thus effectively eliminating the aberration caused by the mismatch between the collimating lens and the objective lens in the existing optical system. Simultaneously, utilize reflective prism 4 to shorten the spatial distance between transceiver unit 13 and collimator lens 5 under the condition that the total optical path of the optical path is guaranteed to be constant, and utilize reflective prism 4 to replace reflective surface mirror, these improvements effectively reduce The volume of the device using the optical read/write system 100 .

Please refer to FIG. 6 , which is a schematic diagram of an optical reading/writing system 100' according to a second embodiment of the present invention. The optical read/write system 100' includes a first optical transceiver unit 11, a second optical transceiver unit 12, a third optical transceiver unit 13, a first diffraction component 21, a second diffraction component 22, a first Three diffraction components 23 , a prism group 3 , a reflective prism 4 ′, a wavelength selection plate 6 and an objective lens 7 .

Please refer to FIG. 7 together, which is a front view of the reflective prism 4' of the optical read/write system 100' in FIG. 6 . The optical components in the optical read/write system 100' are basically the same as the corresponding optical components of the optical read/write system 100 shown in FIG. A triangular prism, which has a fourth light incident surface 40', a fourth light exit surface 42', and a fourth reflection surface 44' connected in sequence, wherein the fourth light incident surface 40' and the fourth light exit surface 42' are perpendicular to each other set up. An angle of 45 degrees is formed between the fourth light emitting surface 42' and the fourth reflecting surface 44', and between the fourth light incident surface 40' and the fourth reflecting surface 44'. The optical signal vertically incident on the fourth light incident surface 40' can be emitted perpendicular to the fourth light exit surface 42' after being reflected by the fourth reflective surface 44', so that the incident light beam passes through the reflective prism 4', and the transmission direction Turn 90 degrees.

Claims (10)

1. An optical read/write system, comprising a first optical transceiver unit, a second optical transceiver unit, a prism group, a reflective prism, a collimator lens, and an objective lens, the first optical transceiver unit has a a first light source for emitting a first incident light beam of a first wavelength; the second optical transceiver unit has a second light source for emitting a second incident light beam of a second wavelength, and the second wavelength is greater than the first wavelength; the prism The group has a first prism located in the common optical path of the first and second incident light beams, a second prism located in the optical path of the third incident light beam and a prism located in the common optical path of the first, second and third incident light beams and will The three incident light beams are output from the third prism at the same position, and the second prism has an end face of an aspheric structure; Angle, the optical signal perpendicular to the light incident surface is reflected between the surfaces of the reflective prism, and then exits perpendicular to the light exit surface; the collimator lens has optical parameters corresponding to the first wavelength, and is located at the first and second , in the optical path shared by the third incident light beam; the objective lens also has optical parameters corresponding to the first wavelength, and is located in the optical path shared by the first, second, and third incident light beams, characterized in that: the optical read/write The system also includes a third optical transceiver unit, the third optical transceiver unit has a third light source for emitting a third incident beam of a third wavelength, the third wavelength is greater than the second wavelength; the first prism has a first A light incident surface, the first light incident surface has a first light incident area for the first incident light beam to pass through and a second light incident area for the second incident light beam to pass through, the second light incident area is an aspheric structured surface . 2 . The optical reading/writing system according to claim 1 , wherein the reflecting prism and the collimating lens are an integral component, and the collimating lens is located on the light-emitting surface of the reflecting prism. 3. The optical reading/writing system according to claim 1, wherein the angle formed by the light-incident surface and the light-emitting surface of the reflective prism is 90 degrees. 4. The optical reading/writing system according to claim 3, wherein the light-incident surface and the light-emitting surface of the reflective prism are two adjacent surfaces. 5. The optical reading/writing system according to claim 1, wherein the reflective prism is a pentagonal prism structure. 6 . The optical reading/writing system according to claim 5 , wherein the included angles between the sides of the pentagonal prism are 112.5 degrees except that the light-incident surface and the light-exit surface are 90 degrees. 7. The optical reading/writing system according to claim 1, characterized in that: the reflective prism is a triangular prism structure, and the included angle between the sides of the triangular prism is 90 degrees except for the light-incident surface and the light-exit surface, and the remaining angles are Both are 45 degrees. 8. The optical reading/writing system according to claim 1, wherein the first, second and third prisms of the prism group are independent of each other, and the first and second prisms are located on the same side of the third prism. 9. The optical read/write system according to claim 1, characterized in that: the first prism also has a first reflective surface and a first optical path conversion interface, and the first light incident surface is at a 45° angle to the first reflective surface degree included angle, the first reflective surface is parallel to the first optical path conversion interface, and the first optical path conversion interface has different reflection or transmission functions for incident light of different wavelengths. 10. The optical reading/writing system according to claim 1, wherein the third prism has a third light incident surface, a third light exit surface, a third reflective surface, and a second light path conversion interface, and the third light incident surface The third light-emitting surface is parallel to the third light-emitting surface, the third light-incident surface forms an angle of 45 degrees with the third reflecting surface, and the third reflecting surface is parallel to the second optical path conversion interface, and the second optical path conversion interface is for incident light of different wavelengths With different reflective or transmissive functions.

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