CN101447201A - Optical head collection device - Google Patents
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- CN101447201A CN101447201A CNA2008101783573A CN200810178357A CN101447201A CN 101447201 A CN101447201 A CN 101447201A CN A2008101783573 A CNA2008101783573 A CN A2008101783573A CN 200810178357 A CN200810178357 A CN 200810178357A CN 101447201 A CN101447201 A CN 101447201A
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Abstract
Provided is an optical head collection device, capable of implementing stable action even though a birefringent quantity is variable in the radius direction of an optical recording disc. In the optical head collection device, the direction of a one second wavelength sheet (24) in a polarization face direction of a laser emitted from a lighting element (11) is adjusted to reduce the dependence of returned light component intensity to the birefringent quantity of the optical recording disc (5) in the same polarization face direction. Also, a phase difference of the other optical element is adjusted by a one sixth wavelength sheet equal polarization transformational element (28), to reduce the intensity level of the returned light component in the same polarization face direction.
Description
Technical field
The present invention relates to carry out the reproduction of optical recording medias such as CD, DVD and/or the optical head collection device of record.
Background technology
Be used for the reproduction of optical recordings such as CD, DVD, the optical head collection device of record, have: the light-emitting component of the laser that emerging ray polarized light (for example P polarized light) is formed; The input photo detector; Object lens; On the half-way of light path, form the diffraction element of main beam and beamlet from laser from light-emitting component toward optical recording; Make the mirror that increases of the vertical bending of light path; And at light-emitting component and increase between the mirror, make back light from optical recording towards the light path resolution element of input with photo detector.
In this optical head collection device, exist part back light to arrive light-emitting component, and optical recording have the situation of birefringence because of the diaphragm that forms on the recording layer surface etc. from optical recording.In this case, when the polarization polarization surface direction that comprises in the back light of arrival light-emitting component and the plane of polarization direction quadrature of light-emitting component emitting laser, not producing both sides interferes, but when the polarization polarization surface direction that comprises in the back light of arrival light-emitting component is identical with the plane of polarization direction of light-emitting component emitting laser, produce to interfere, and the S/N ratio that the produces signal variety of issues such as deterioration, fader control is not good enough that reduce, beat.
Therefore, propose the double refraction amount of measuring light indicator,, make the photoelectric crystal elements act, proofread and correct the double refraction amount (refer to Patent Document 1, patent documentation 2) of optical recording according to this measurement result.
Also propose the dichroism of improvement light path resolution element, reduce the arrival amount (refer to Patent Document 3) of back light photo detector.
Patent documentation 1: the spy of Japan opens communique 2004-No. 39018
Patent documentation 2: the spy of Japan opens communique 2004-No. 273089
Patent documentation 3: the spy of Japan opens flat 7-No. 249233 communiques
Yet, in the optical recording, there be the situation of double refraction amount in the radial direction variation of optical recording, under this situation, there is the problem that can not tackle in prior art.
Again, owing to be configured in phase differential, parts, the installation accuracy difference that the optical element itself on the light path has, often laser does not arrive optical recording with the circular polarization state, and to this problem, there is the problem that can not tackle in prior art.
In view of the above problems, problem of the present invention is, even propose double refraction amount also can be realized stable action under the situation of the radial direction variation of optical recording optical head collection device.
Summary of the invention
In order to solve above-mentioned problem, among the present invention, optical head collection device has: the light-emitting component of the laser that the emerging ray polarized light is formed; The input photo detector; With the increase mirror of described light-emitting component emitting laser toward described optical recording reflection; And light path resolution element, this light path resolution element is described light-emitting component and described increasing between the mirror, make back light from described optical recording towards described input photo detector, wherein, the light path from described light-emitting component toward described optical recording, dispose 1/2 wavelength sheet between the mirror at described light-emitting component and described increasing, this 1/2 wavelength sheet is adjusted the plane of polarization direction of described light-emitting component emitting laser, and this 1/2 wavelength sheet is configured to have in arriving the described back light of described light-emitting component with the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording reduces.
The present invention disposes 1/2 wavelength sheet, this 1/2 wavelength sheet is adjusted the plane of polarization direction of light-emitting component emitting laser, and this 1/2 wavelength sheet is configured to have in the described back light that arrives described light-emitting component with the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording reduces.Therefore, even in the birefringence that has owing to optical recording, the part back light arrives light-emitting component through the light path resolution element, and under the birefringence that has of the optical recording situation about changing because of the position on the optical recording, arrive the intensity that has in the back light of light-emitting component with the polarized light component of the same plane of polarization direction of light-emitting component emitting laser also below the certain intensity level.Therefore, can prevent the interference of back light and light-emitting component emitting laser.
Among the present invention, for example from departing from the angle direction that the direction (hereinafter referred is a radial direction) that the reflection position that increases mirror by this is extended toward the radial direction of described optical recording becomes the directions of 45 degree, to the described described light-emitting component emitting laser of mirror incident that increases.
Among the present invention, double refraction amount with described optical recording is an X-axis, when arriving the intensity that has in the described back light of described light-emitting component with the polarized light component of the same plane of polarization direction of described light-emitting component emitting laser and being the Y-axis generating writing pattern, it is the line symmetry of center line that described 1/2 wavelength sheet is configured to the Y-axis that the curve described in this figure forms when described double refraction amount being fixed in the value of regulation, has in the described back light of described light-emitting component and the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording thereby reduce to arrive.For example, is that benchmark is when doing optical design with the double refraction amount of optical recording for ± 0, described 1/2 wavelength sheet is configured to the curve described in this figure, and to form with described double refraction amount be the line symmetry of center line for ± 0 Y-axis, has in the described back light of described light-emitting component and the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording thereby reduce to arrive.
Among the present invention, be preferably in the polarization conversion device of the phase differential that other optical element of configuration compensation produces on the described light path.Do like this on the structure, the intensity level itself that has in the back light that arrives light-emitting component with the polarized light component of the same plane of polarization direction of light-emitting component emitting laser is reduced.
Among the present invention, preferably form described 1/2 wavelength sheet and other optical element that is configured on the described light path with being integrated.Do like this on the structure, compare, 1/2 wavelength sheet can be configured in the direction of regulation with the situation of the described 1/2 wavelength sheet of independent configuration.
Among the present invention, the half-way that is preferably in described light path is equipped with the laser that produces from described light-emitting component and produces the diffraction element of main beam and beamlet, and forms described 1/2 wavelength sheet and described diffraction element with being integrated.Do like this on the structure, compare, 1/2 wavelength sheet can be configured in the direction of regulation with the situation of the described 1/2 wavelength sheet of independent configuration.Especially under the situation of diffraction element, itself also is configured in the direction of regulation, therefore easily 1/2 wavelength sheet is configured in accurately the direction of regulation.
Among the present invention, preferably close and form described 1/2 wavelength sheet, described polarization conversion device and described diffraction element.
In the case, preferably described 1/2 wavelength sheet is configured in position with respect to the more approaching described polarization conversion device of described diffraction element.Do like this on the structure, can diffraction element and 1/2 wavelength sheet be integrated with high precision.
Optical head collection device of the present invention disposes 1/2 wavelength sheet, this 1/2 wavelength sheet is adjusted the plane of polarization direction of light-emitting component emitting laser, and this 1/2 wavelength sheet is configured to have in the described back light that arrives described light-emitting component with the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording reduces.Therefore, even in the birefringence that has owing to optical recording, the part back light arrives light-emitting component through the light path resolution element, and under the birefringence that has of the optical recording situation about changing because of the position on the optical recording, arrive the intensity that has in the back light of light-emitting component with the polarized light component of the same plane of polarization direction of light-emitting component emitting laser also below the certain intensity level.Therefore, can prevent S/N ratio because of back light and the interference signal of the light-emitting component emitting laser variety of issues such as deterioration, fader control is not good enough that reduce, beat.
Description of drawings
Fig. 1 is a summary composition diagram of using the optical system key portion of optical head collection device of the present invention.
Fig. 2 is the key diagram that the composition of using the composite optic element that uses in the optical head collection device of the present invention is shown.
Fig. 3 illustrates in the optical head collection device key diagram of the long axis direction of angle that the line that connects the reflection position that increases on the mirror and light-emitting component forms the radial direction of optical recording and elliptically polarized light to the relation of the angle of disc radial direction formation.
Fig. 4 illustrates the intensity of back light component of angle that the line that connects the reflection position increase on the mirror and light-emitting component in the simulation optical head collection device forms the radial direction of optical recording and same plane of polarization direction to the result's of the dependent relation of the double refraction amount of optical recording curve map.
Fig. 5 angle that to be line that the reflection position that connection increased on the mirror and light-emitting component be shown in the optical head collection device form the radial direction of optical recording is taken as 35 and simulates the intensity of back light component of the angle position of 1/2 wavelength sheet and same plane of polarization direction when spending to the result's of the dependent relation of the double refraction amount of optical recording curve map.
Fig. 6 be when the angle position of simulative optimization 1/2 wavelength sheet in the optical head collection device is shown and the intensity of the back light component of the same plane of polarization direction when utilizing polarization conversion device phase calibration difference to the dependent result's of the double refraction amount of optical recording curve map.
Fig. 7 illustrates the intensity of back light component of the angle position of simulation 1/2 wavelength sheet and polarization conversion device and same plane of polarization direction to the result's of the dependent relation of the double refraction amount of optical recording curve map.
Fig. 8 illustrates the intensity of back light component of the phase differential of simulation 1/2 wavelength sheet and polarization conversion device and same plane of polarization direction to the result's of the dependent relation of the double refraction amount of optical recording curve map.
Label declaration
The 5th, optical recording, the 10th, optical head collection device, the 11st, light-emitting component, the 12nd, input photo detector, the 13rd, increase mirror, the 14th, half-mirror (light path resolution element), the 20th, composite optic element, the 21st, diffraction element, 24 is 1/2 wavelength sheets, the 26th, polarization conversion device.
Embodiment
Below, use the embodiment of optical head collection device of the present invention with reference to description of drawings.
(the optical system basic composition of optical head collection device)
Fig. 1 and Fig. 2 are respectively the summary composition diagrams and the key diagram that the composition of the composite optic element that is used for this optical head collection device is shown of using the optical system key portion of optical head collection device of the present invention.
Among Fig. 1, the optical head collection device 10 of the manner is the reproduction that is used for optical recordings 5 such as CD, DVD, the device of record, has the light-emitting component 11 of the laser of emerging ray polarized light (for example P polarized light) composition; Input photo detector 12; Object lens (not shown); , on the half-way of 5 light path from light-emitting component 11 toward optical recording, form the diffraction element 21 of main beam and beamlet from laser; What make the vertical bending of light path increases mirror 13; And at light-emitting component 11 and increase between the mirror 13, make back light from optical recording 5 towards the half-mirror 14 (light path resolution element) of input with photo detector 12.
Configuration polarization conversion device 26 in light path also, phase differential and polarization conversion device 26 that present embodiment utilizes half-mirror 14 to have, making light-emitting component 11 emitting lasers is circularly polarized light or circularly polarized light in fact, and towards optical recording 5.In the present embodiment,, use 1/6 wavelength sheet as polarization conversion device 26.
Like this in the optical head collection device 10 of Gou Chenging, after light-emitting component 11 emitting lasers penetrate half-mirror 14, reflection on the reflecting surface 130 that increases mirror 13, as circularly polarized light or in fact circularly polarized light arrive optical recording 5 by object.In contrast, from the back light of optical recording after reflection on the reflecting surface 130 that increases mirror 13, reflection on half-mirror 14, and arriving signal detects with photo detector 12.
In the optical head collection device 10 of Gou Chenging, optical recording 5 for example has birefringence because of the diaphragm that is formed on the recording layer surface, and often double refraction amount changes on the radial direction of optical recording 5 like this.That the double refraction amount of this optical recording 5 exists usually is big on the radial direction inboard of optical recording 5, little trend is gone up in the radial direction outside.When using this CD 5, be elliptically polarized light, so the polarized light component that has with the same plane of polarization of the plane of polarization of light-emitting component 11 emitting lasers arrives light-emitting component 11 from the back light of optical recording 5.Its result produce to interfere between light-emitting component 11 emitting lasers and the back light, makes the quality deterioration of light-emitting component 11 emitting lasers, thereby the S/N ratio that the produces signal variety of issues such as deterioration, fader control is not good enough that reduce, beat.
Therefore, the manner is in light path, and 1/2 wavelength sheet 24 of the plane of polarization direction of light-emitting component 11 emitting lasers is adjusted in configuration between light-emitting component 11 and the half-mirror 14.Here, shown in Fig. 2 (a) and (b), 1/2 wavelength sheet 24 and polarization conversion device 26 stacks on diffraction grating 21, are constituted as the composite optic element 20 of one.In the manner, the structure that composite optic element 20 forms is simultaneously pressurizeed to the grating face of diffraction grating 21 state with the substrate 28 of the light transmission of the bonding agent 27 of the bonding agent 25 of bonding agent 23, the 1/2 wavelength sheet 24 of the substrate 22 of the stacked for example light transmission that 0.8 millimeter (mm) is thick, UV hardening printing opacity, UV hardening printing opacity, polarization conversion device 26, UV hardening printing opacity and 0.7 millimeters thick, and one side makes bonding agent 23,25,27 obtain the UV sclerosis.
(detailed descriptions of the layout of relevant optical element etc.)
Fig. 3 illustrates in the optical head collection device key diagram of the long axis direction of angle that the line that connects the reflection position that increases on the mirror and light-emitting component forms the radial direction of optical recording and elliptically polarized light to the relation of the angle of disc radial direction formation.Fig. 4 illustrates the curve map of the intensity (intensity of the back light component of hereinafter referred to as same plane of polarization direction) of the polarized light component that has the plane of polarization identical with the plane of polarization of light-emitting component (LD) emitting laser in angle that the line that connects the reflection position increase on the mirror and light-emitting component in the simulation optical head collection device forms the radial direction of optical recording and the back light to the result of the dependent relation of the double refraction amount of optical recording.Fig. 5 angle that to be line that the reflection position that connection increased on the mirror and light-emitting component be shown in the optical head collection device form the radial direction of optical recording is taken as 35 and simulates the curve map of the intensity of angle position (hereinafter referred is the angle position) and the back light component of same plane of polarization direction around the optical axis of 1/2 wavelength sheet to the result of the dependent relation of the double refraction amount of optical recording when spending.Fig. 6 be when the angle position of simulative optimization 1/2 wavelength sheet in the optical head collection device is shown and the intensity of the back light component of the same plane of polarization direction when utilizing polarization conversion device phase calibration difference to the dependent result's of the double refraction amount of optical recording curve map.Fig. 7 illustrates the intensity of back light component of the angle position of simulation 1/2 wavelength sheet (HWP) and polarization conversion device (QWP) and same plane of polarization direction to the result's of the dependent relation of the double refraction amount of optical recording curve map.Fig. 8 illustrates the intensity of back light component of the phase differential of simulation 1/2 wavelength sheet and polarization conversion device and same plane of polarization direction to the result's of the dependent relation of the double refraction amount of optical recording curve map.Moreover, use Jones vector in the computing during various the simulation.Among Fig. 4～Fig. 8, be that the intensity that has the polarized light component of the plane of polarization direction identical with the light-emitting component emitting laser in X-axis, the back light that arrives light-emitting component 11 is Y-axis all with the double refraction amount of optical recording, generating writing pattern.
In the manner,, utilize the direction of optimizing 1/2 wavelength sheet 24 and adopt polarization conversion device 26, prevent the interference between light-emitting component 11 emitting lasers and the back light according to reason described below.
At first, in the optical head collection device 10, utilize the layout of optical system, the long axis direction of regulation when light-emitting component 11 sees that birefringence because of optical recording 5 becomes the back light of elliptically polarized light.Promptly, as shown in Figure 1, the line (radial direction of optical recording 5) of the reflection position on connecting the center O of optical recording 5 and increasing mirror 13 and the angle θ 1 of line (from light-emitting component 11 toward the incident direction that increases mirror 13, from increasing the reflection direction of the mirror 13) formation that is connected the reflection position that increases on the mirror 13 and light-emitting component 11 toward light-emitting components 11 be changed to 0 spend, 20 spend, 40 when spending, shown in Fig. 3 (a) and (b), (c), the angle that the long axis direction of elliptically polarized light forms disc radial direction is changed to 0 degree, 20 degree, 40 degree respectively.
This angle θ 1 is set at 0 degree, 20 degree, 35 degree, 40 degree, 55 when spending, and the intensity of back light component of simulating same plane of polarization direction then becomes result shown in Figure 4 to the dependence of the double refraction amount of optical recording 5.Here, be set at 30 degree with penetrating the P polarized light behind the half-mirror 14 and the phase differential of S polarized light.Distinguish from Fig. 4, the back light component intensity of same plane of polarization direction changes greatly because of angle θ 1 dependence of the double refraction amount of optical recording 5, at angle θ 1 is 45 when spending, the back light component intensity of same plane of polarization direction is just equal as long as the double refraction amount absolute value equates, positive and negative (±) of being regardless of double refraction amount.That is to say that among Fig. 4, angle θ 1 is 45 when spending, it is the line symmetry of center line that curve becomes with the Y-axis of double refraction amount ± 0.
In contrast, angle θ 1 is 35 when spending, the back light component intensity of same plane of polarization direction is asymmetric when double refraction amount positive and negative (±), the back light component intensity level of same amount of bias direction was little when double refraction amount was negative, but double refraction amount is timing, and the back light component intensity level of same plane of polarization direction is big.So the back light component intensity of same amount of bias direction is big to the dependence of the double refraction amount of optical recording 5.Therefore, the polarized light component with plane of polarization identical with the plane of polarization of light-emitting component 11 emitting lasers incides light-emitting component 11 with high strength.
So, simulation is fixed as 35 degree with described angle θ 1, only with 1/2 wavelength sheet, 24 angle θ 2 from reference position deviation angle ± 0 degree ,-2 degree ,-6 degree ,+6 degree ,+2.5 the back light component intensity of same plane of polarization direction when spending are to the dependence of the double refraction amount of optical recording 5, then become result shown in Figure 5.When setting for this reason condition, increase in the mirror 13, depart from the angle directions of 45 degree, incident light-emitting component 11 emitting lasers from radial direction to optical recording 5.The phase differential that penetrates P polarized light behind the half-mirror 14 and S polarized light also former state is 30 degree.Even under the situation of She Dinging, distinguish from Fig. 5 like this, when changing the angle θ 2 of 1/2 wavelength sheet 24, the back light component intensity of same plane of polarization direction also changes greatly the dependence of the double refraction amount of optical recording 5.Promptly, when changing the angle θ 2 of 1/2 wavelength sheet 24, big and angle θ 2 be under+2.5 situations about spending to the back light component intensity of same plane of polarization direction in positive and negative (±) slope variation of double refraction amount, even angle θ 1 is 35 degree, the back light component intensity of same plane of polarization direction just equates as long as the double refraction amount absolute value equates this intensity, and its intensity level is little, is regardless of double refraction amount positive and negative (±).That is to say, even angle θ 1 is 35 when spending, if optimize the angle θ 2 of 1/2 wavelength sheet 24, then curve also can become with double refraction amount to be the line symmetry of center line for ± 0 Y-axis, can to reduce the dependence of the back light component intensity of same amount of bias direction to the double refraction amount of optical recording 5.Under this condition, do not exist polarized light component to incide the situation of light-emitting component with high strength with amount of bias identical with the amount of bias direction of light-emitting component 11 emitting lasers.
Spend in optical head collection device 10, angle θ 1 being taken as 35 like this, angle θ 2 is taken as 0 the back light component intensity of same plane of polarization direction when spending and is taken as 35 degree to the dependence of the double refraction amount of optical recording 5 with angle θ 1, angle θ 2 is taken as+the back light component intensity of same plane of polarization direction when 2.5 degree are spent to the dependence of the double refraction amount of optical recording 5 respectively as shown in Figure 6 with solid line L1, L2 compares, distinguish thus angle θ 1 is taken as 35 degree, angle θ 2 is taken as+2.5 when spending, can reduce the dependence of the back light component intensity of same plane of polarization direction to the double refraction amount of optical recording 5.
Again, angle θ 2 is taken as+2.5 the degree, angle θ 1 be taken as 35 the degree situations under, when utilizing polarization conversion device 28 to proofread and correct to penetrate the phase differential of P polarized light behind the half-mirror 14 and S polarized light, shown in the solid line L3 of Fig. 6, can reduce the back light component intensity level of same plane of polarization direction.
Moreover, the result who obtains after the angle θ 2 that Fig. 7 (a) illustrates simulation 1/2 wavelength sheet 24 and the dependent relation of back light component intensity to the double refraction amount of optical recording 5 of same plane of polarization direction, Fig. 7 (b) illustrate the result who obtains after the dependent relation of back light component intensity to the double refraction amount of optical recording 5 of the angle position of simulation polarization conversion device 26 and same plane of polarization direction.Distinguish from these figure, the angle position of the angle position ratio polarization inverting element 26 of 1/2 wavelength sheet 24, big to the back light component intensity of same plane of polarization direction to the dependent influence of the double refraction amount of optical recording 5.
Again, Fig. 8 (a) illustrates the result who obtains after the dependent relation of back light component intensity to the double refraction amount of optical recording 5 of phase differential and same plane of polarization direction of simulation 1/2 wavelength sheet 24, and Fig. 8 (b) illustrates the result who obtains after the dependent relation of back light component intensity to the double refraction amount of optical recording 5 of the phase differential of simulating polarization conversion device 26 and same plane of polarization direction.Distinguish from these figure, the phase differential of polarization conversion device 26 is than the phase differential of 1/2 wavelength sheet 24, back light component intensity to same plane of polarization direction is big to the dependent influence of the double refraction amount of optical recording 5, and allows about phase differential skew 15 degree of 1/2 wavelength sheet 24.Therefore, when making the composite optic element 20 with reference to Fig. 2 explanation, even under the situation about changing because of the phase differential of the influence 1/2 wavelength sheet 24 of bonding agent 23,25, also can reduce same by the intensity level of the back light component of film forming direction.
(the main effect of the manner)
As mentioned above, in the optical head collection device 10, exchanging the direction of 1/2 wavelength sheet 24 of the plane of polarization direction of optical element 11 emitting lasers of haircuting adjusts, then can reduce the dependence of the back light component intensity of same plane of polarization direction to the double refraction amount of optical recording 5, even therefore arrive light-emitting component 11 because of optical recording 5 has birefringence part back light, and under the birefringence that has of optical recording 5 situation about changing because of the position on the optical recording, arrive in the back light of light-emitting component 11, have with the polarized light component intensity of the same plane of polarization direction of light-emitting component 11 emitting lasers also can be below the certain intensity level.
Again, utilize polarization inverting elements 28 such as 1/6 wavelength sheet, proofread and correct the phase differential that other optical element has, therefore the intensity level of the back light component of same plane of polarization direction is reduced.
So, according to the manner, even with the interior all sides of optical recording 5 or the double refraction amount of outer circumferential side is that benchmark carries out under the situation of optical design, when the arbitrary position on the optical recording 5 being carried out recording of information or reproducing, also can reduce to arrive the intensity that has the polarized light component of the plane of polarization direction identical in the back light of light-emitting component 11 reliably with light-emitting component 11 emitting lasers.Therefore, can prevent because of S/N ratio that the interference between back light and light-emitting component 11 emitting lasers produces signal variety of issues such as deterioration, power control is not good enough that reduce, beat.
In the manner, 1/2 wavelength sheet 24 and polarization conversion device 28 are constituted composite optic element 20 with diffraction element 21 with being integrated again.Therefore, illustrated as reference Fig. 7 and Fig. 8, even the angle position of 1/2 wavelength sheet 24 requires under the high-precision situation, owing to form 1/2 wavelength sheet 24 with other optical element, the precision highland is configured in the direction of regulation in the time of also can be than independent configuration 1/2 wavelength sheet 24 with being integrated.And, forming 1/2 wavelength sheet 24 with diffraction element 21 with being integrated, diffraction element 21 is adjusted the angle position according to electric signal in the assembling procedure of optical head collection device 10, so diffraction element 21 itself is configured in the direction of regulation accurately.Thereby, the easy direction that 1/2 wavelength sheet 24 is configured in accurately regulation.
In the manner, 1/2 wavelength sheet 24 is configured in respect to diffraction element 21 more near the position of polarization conversion device 28 (polarization conversion device) again.Do like this on the structure, can diffraction element 21 and 1/2 wavelength sheet 24 be integrated with high precision.
(other embodiment)
In the aforesaid way, 1/2 wavelength sheet 24 and polarization conversion device 28 are constituted composite optic element 20 with diffraction element 21 with being integrated, but also can for example on the reflecting surface 130 that increases mirror 13, form polarization conversion device 28 at other position.In the case, in the optical head collection device 10, adjust the direction of 1/2 wavelength sheet 24, make laser be offset the angle incident of 45 degree to the vertical plane that comprises incident direction and reflection direction that erects from the reflecting surface that increases mirror 15 with its plane of polarization from light-emitting component 11 toward optical recording 5.Do like this on the structure, can reduce the dependence of the back light component intensity of same plane of polarization direction to the double refraction amount of optical recording 5, even therefore arrive light-emitting component 11 because of optical recording 5 has birefringence part back light, and under the birefringence that has of optical recording 5 situation about changing because of the position on the optical recording, arriving the polarized light component intensity that has in the back light of light-emitting component 11 with the same plane of polarization direction of light-emitting component 11 emitting lasers also can be below the certain intensity level.
Again, in the described mode, with the double refraction amount of optical recording 5 is that the polarized light component intensity that has the plane of polarization direction identical with light-emitting component 11 emitting lasers in X-axis, the back light that arrives light-emitting component 11 is when being the Y-axis generating writing pattern, the curve that 1/2 wavelength sheet 24 is configured to describe in the figure for be fixed in double refraction amount ± 0 o'clock Y-axis is the line symmetry of center line, but the curve that also 1/2 wavelength sheet 24 can be configured to describe in the figure for be fixed in double refraction amount ± Y-axis during setting beyond 0 is the line symmetry of center line.
Again, can half-mirror 14 and increase between the mirror 13 or increase mirror 13 and optical recording 5 between, the configuration polarization conversion device 28.
Also can be taken as the composition that omits polarization conversion device 28.Again, as the light path resolution element, also available prism or diffraction element are to replace half-mirror 14.Also the present invention can be used for the light-emitting component emitting laser reflected on the light path resolution element and be directed to optical recording and make the transmission and be directed to the optical head collection device of input on the light path resolution element of back light from optical recording with photo detector.
Again, aforesaid way is that light-emitting component 11 is 1 a example, also can use the present invention but be equipped with in the optical head collection device 10 of a plurality of light-emitting components.
Claims (9)
1, a kind of optical head collection device has:
The light-emitting component of the laser that the emerging ray polarized light is formed;
The input photo detector;
With the increase mirror of described light-emitting component emitting laser toward described optical recording reflection; And
Light path resolution element, this light path resolution element be described light-emitting component and described increasing between the mirror, makes back light from described optical recording towards described input photo detector, it is characterized in that,
The light path from described light-emitting component toward described optical recording, dispose 1/2 wavelength sheet between the mirror at described light-emitting component and described increasing, this 1/2 wavelength sheet is adjusted the plane of polarization direction of described light-emitting component emitting laser, and
This 1/2 wavelength sheet is configured to have in arriving the described back light of described light-emitting component with the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording reduces.
2, the optical head collection device described in claim 1 is characterized in that,
Described increasing in the mirror is from departing from the angle direction that the direction that the reflection position that increases mirror by this is extended toward the radial direction of described optical recording becomes the directions of 45 degree, the described light-emitting component emitting laser of incident.
3, the optical head collection device described in claim 1 is characterized in that,
With the double refraction amount of described optical recording is when having intensity with the polarized light component of the same plane of polarization direction of described light-emitting component emitting laser in X-axis, the described back light that arrives described light-emitting component and being the Y-axis generating writing pattern,
It is the line symmetry of center line that described 1/2 wavelength sheet is configured to the Y-axis that the curve described in this figure forms when described double refraction amount being fixed in the value of regulation, has in the described back light of described light-emitting component and the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording thereby reduce to arrive.
4, the optical head collection device described in claim 3 is characterized in that,
Described 1/2 wavelength sheet is configured to the curve described in the described figure, and to form with described double refraction amount be the line symmetry of center line for ± 0 Y-axis, has in the described back light of described light-emitting component and the intensity of the polarized light component of the same plane of polarization direction of the described light-emitting component emitting laser dependence to the double refraction amount of described optical recording thereby reduce to arrive.
5, the optical head collection device described in claim 1 is characterized in that,
On described light path, the polarization conversion device of the phase differential that other optical element of configuration compensation produces.
6, the optical head collection device described in claim 1 is characterized in that,
Form described 1/2 wavelength sheet and other optical element that is configured on the described light path with being integrated.
7, the optical head collection device described in claim 1 is characterized in that,
In the half-way of described light path, be equipped with the diffraction element that produces main beam and beamlet from described light-emitting component emitting laser, and
Form described 1/2 wavelength sheet and described diffraction element with being integrated.
8, the optical head collection device described in claim 5 is characterized in that,
Form described 1/2 wavelength sheet, described polarization conversion device and described diffraction element with being integrated.
9, the optical head collection device described in claim 8 is characterized in that,
Described 1/2 wavelength sheet is configured in position with respect to the more approaching described polarization conversion device of described diffraction element.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007304647A JP2009129514A (en) | 2007-11-26 | 2007-11-26 | Optical head device |
| JP2007304647 | 2007-11-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101447201A true CN101447201A (en) | 2009-06-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008101783573A Pending CN101447201A (en) | 2007-11-26 | 2008-11-26 | Optical head collection device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2009129514A (en) |
| CN (1) | CN101447201A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111936799A (en) * | 2018-04-04 | 2020-11-13 | 株式会社Kelk | Fluid heating device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013242932A (en) * | 2010-09-08 | 2013-12-05 | Sanyo Electric Co Ltd | Optical pickup device |
-
2007
- 2007-11-26 JP JP2007304647A patent/JP2009129514A/en active Pending
-
2008
- 2008-11-26 CN CNA2008101783573A patent/CN101447201A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111936799A (en) * | 2018-04-04 | 2020-11-13 | 株式会社Kelk | Fluid heating device |
| US11985736B2 (en) | 2018-04-04 | 2024-05-14 | Kelk Ltd. | Fluid heating device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009129514A (en) | 2009-06-11 |
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Open date: 20090603 |