JP6176169B2 - Diffraction grating holder - Google Patents

Description

  The present invention relates to a diffraction grating holder that holds a diffraction grating in an optical pickup.

Patent Documents 1 to 3 relating to an optical pickup device that holds a diffraction grating (grating) and mounting a diffraction grating used therefor are known.
Patent Document 1 relates to an optical pickup device and a diffraction grating mounting method used therefor. In FIGS. 3 and 4 and paragraphs 0028 to 0031 of the same document, “the adjustment tool 110 is inserted into the groove 109 a of the diffraction grating holder 109 and the adjustment tool 110 is moved in the direction of arrow A to adjust the diffraction grating 102. There is disclosure.

Patent Document 2 relates to an optical pickup device. In FIGS. 3 and 5 and paragraphs 0063 to 0064 of the document, “the projection 20 of the second holder 17 is moved in the X direction by a position adjusting jig (not shown) to move the diffraction grating holder 14. , "Adjust the diffraction grating".
Patent Document 3 relates to an optical pickup device. 5 and 6 and paragraphs 0046 to 0048 of the same document disclose that “the first and second diffraction gratings 30 and 40 are adjusted by moving the adjustment pieces 33 and 43 to the holders 32 and 42”.

JP 2011-86320 A JP 2011-70771 A JP 2005-285166 A

When adjusting the angle of the diffraction grating, the position of the diffraction grating holder is finely adjusted with an adjustment tool. In the conventional technology described above, adjustment of the position of the diffraction grating holder requires accuracy, but there is a limit to the accuracy at the portion where the adjustment tool is brought into contact with the diffraction grating holder.
The present invention provides a diffraction grating holder capable of finely moving the diffraction grating holder with high accuracy.

  The present invention is a diffraction grating holder for holding a diffraction grating in an optical pickup, wherein a holder main body portion formed in a substantially frame shape with a sheet metal and a part of the holder main body portion are folded back so that the sheet metals overlap on one side. A configuration in which an overlapping part formed on the overlapping side and each sheet metal overlapping with the overlapping side are formed with a crossing part where the substantially linear edges of each cutting part intersect with each other while forming the cutting part so as to overlap each other. It is as.

  In the present invention configured as described above, the holder main body portion is formed of a sheet metal in a substantially frame shape, and a part of this holder main body portion is folded back to form overlapping sides so that the metal plates overlap on one side. Yes. In each sheet metal that overlaps at the overlapping side, cut portions are formed so as to overlap each other, and the cut portions substantially overlap. However, substantially straight edge portions are formed in the respective cut portions, and the substantially straight edge portions intersect with each other to form an intersection portion.

  When the edges cross each other, an acute-angled portion is formed like a heel blade. If an attempt is made to form this with only a valley cut in one side of a sheet metal, a slight R will be formed at the bottom of the valley. Then, a sharp adjustment tool is brought into contact with the valley bottom and finely moved to adjust. However, even if the adjustment tool side is sharp, if there is R in the valley bottom, it may slip slightly on the valley bottom.

On the other hand, at the intersection where the substantially linear edges intersect each other, there is no room for R to intersect at the portion corresponding to the bottom of the valley like a spear blade. Therefore, even if it makes a sharp adjustment tool contact, it does not slip.
It should be noted that the substantially straight edge portion does not need to be exactly a straight line, and may be a shape that deviates from the straight line, such as gently drawing an arc.
In another aspect of the present invention, the cut portions overlapping each other are each formed in a substantially valley shape and are superposed so that the valley bottoms are displaced.

In the present invention configured as described above, it is necessary that the two hypotenuses intersect at the deepest portion in order to form a generally valley shape. When two roughly valley-shaped shapes are overlapped and the valley bottom is shifted, the edge forming one valley shape and the edge forming the other valley shape intersect. Since the edges of each other are generally linear, there is no limit to R at the intersection.
In another aspect of the present invention, the cut portions that overlap each other have at least edges that intersect each other, and the edges cross each other to form the intersecting portions.

  In the present invention configured as described above, the cut portions that overlap each other only need to have edges with angles that intersect each other. In the simplest case, it is conceivable that the valley bottoms are overlapped with each other, but even if one is a square recess and the other is a semicircular cutout, if there are edges that cross each other, Infinite R does not occur.

In another aspect of the present invention, when the cut portion is formed on the top side of the main body, the overlapping side is formed so that the top sides overlap by folding back the side of the main body. .
In order to reduce the number of parts, it is advantageous to form the overlapping sides by folding the sheet metal.
In the present invention configured as described above, the side edges of the main body are folded so that the top edges overlap each other.

In another aspect of the present invention, when the cut portion is formed on the top side of the main body portion, the overlapping side is formed so as to overlap the top side by folding the bottom side of the main body portion toward the top side. As a configuration.
In the present invention configured as described above, the bottom side of the main body is folded back to the top side so as to overlap the top side.

  According to the present invention, since the straight edges are crossed, there is no room for R to be generated at the crossing, and it is prevented from slipping when a sharp adjustment tool is brought into contact with it. A diffraction grating holder can be provided.

It is a perspective view which shows schematic structure of an optical pick-up. It is a front view of the diffraction grating holder of the present invention. It is a partial enlarged front view of the diffraction grating holder of the present invention. It is a front view of the diffraction grating holder concerning a 2nd example. It is the elements on larger scale of the diffraction grating holder concerning a 2nd example. It is a perspective view of the diffraction grating holder which shows vertical folding. It is a perspective view of the diffraction grating holder which shows horizontal folding. It is a side view which shows the relationship between the width | variety of an adjustment tool, and the width | variety of the return of a diffraction grating holder. It is a front view of the diffraction grating holder before improvement. It is a partial enlarged front view of the diffraction grating holder before improvement.

(First Example)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an optical pickup using the diffraction grating holder of the present invention will be described.
FIG. 1 is a perspective view showing a schematic configuration of the optical pickup.
The light emitting element 11 includes a laser diode corresponding to DVD and CD, and faces the diffraction grating 12. For convenience of explanation, the laser diode is hereinafter referred to as a DVD. The laser light emitted from the light emitting element 11 passes through the diffraction grating 12 and is incident on the half mirror 13, and its path is bent 90 degrees in the horizontal plane and enters the polarizing beam splitter 14. A collimator lens 15 is interposed on the optical path that has passed straight through the polarizing beam splitter 14, and a DVD-side launch mirror 16 is disposed further ahead. Therefore, the laser light is bent 90 degrees vertically, The light passes through the wave plate 17 and the objective lens 18 and is irradiated to a predetermined position of the DVD optical disk. The reflected light from the DVD optical disk travels in the reverse path to the objective lens 18 and the wave plate 17, the launch mirror 16, the collimator lens 15, and the polarization beam splitter 14, and enters the half mirror 13. A part of the half mirror 13 is bent toward the light emitting element 11, but the rest passes straight through the half mirror 13 and enters the light receiving element 20 through the hologram 19.

  Further, in correspondence with the Blu-ray Disc (BD), a light emitting element 21 is also provided. When laser light emitted from the light emitting element 21 enters the polarization beam splitter 14, its path is bent 90 degrees in a horizontal plane, Follow the same path as the DVD laser beam. A collimator lens 15 is interposed on the optical path of the laser light emitted from the polarization beam splitter 14, and further enters the launch mirror 16 on the DVD side. However, the laser beam of the Blu-ray disc passes through the launch mirror 16 on the DVD side, is bent 90 degrees vertically by the launch mirror 22 for the Blu-ray disc, and passes through the wave plate 23 and the objective lens 24. Irradiated to a predetermined position of the optical disc of the Blu-ray disc. The reflected light from the optical disk of the Blu-ray disc travels in the reverse path to the objective lens 24, the wave plate 23, the launch mirror 22, the collimator lens 15, and the polarization beam splitter 14, and enters the half mirror 13. A part of the half mirror 13 is bent toward the light emitting element 11, but the rest passes straight through the half mirror 13 and enters the light receiving element 20 through the hologram 19. A front monitor 25 for adjusting the optical axis is arranged on the extension of the optical path from the half mirror 13 to the launch mirrors 16 and 22.

FIG. 2 shows the diffraction grating holder of the present invention in a front view, and FIG. 3 shows the diffraction grating holder of the present invention in a partially enlarged front view.
The diffraction grating 12 is configured by supporting a diffraction grating element (not shown) with a diffraction grating holder 31. Although a diffraction grating element is arranged and penetrated on the path of the laser beam of the DVD, it is necessary to adjust the relative angular relationship between the laser beam and the diffraction grating. As an example, the rotation angle position of the diffraction grating element may be adjusted relatively around the axis of the diffraction grating element with the path of the laser beam as the axis of rotation. However, the rotation center of the diffraction grating element does not necessarily need to be the optical axis center of the laser beam. In other words, it is necessary to adjust the relative angle between the laser beam and the diffraction grating element in a range where the optical axis of the laser beam does not protrude from the effective diameter of the diffraction grating element. For such adjustment, the diffraction grating holder 31 is formed in a substantially frame shape (corresponding to the holder main body) with a substantially rectangular plate material (sheet metal), and a support protrusion whose tip is formed in a mountain shape from the lower side (bottom side). 32 and a contact recess (cut portion) 33 formed in a substantially valley shape is formed on the upper side (top side). The adjustment bit 41 having a sharp tip from above is brought into contact with the contact recess 33.

Here, the diffraction grating holder before improvement will be described.
FIG. 9 shows the diffraction grating holder before improvement in a front view, and FIG. 10 shows the diffraction grating holder before improvement in a partially enlarged front view.
Also in the diffraction grating holder 91 before improvement, a support protrusion 92 is formed on the lower side (bottom side), and a contact concave portion 93 formed in a valley shape is formed on the upper side (top side).

The diffraction grating holder 91 is formed by folding (hemming bending) a single flat plate material on the lower side, and the folded both ends substantially overlap to form the top side. In this sense, the top side is an overlapping side formed so that a part of the holder main body part is folded and the sheet metals are overlapped on one side.
Here, the plate material on the side folded from the lower side to the top side is referred to as a folded plate 91b, and the plate material on the other side is referred to as a substrate 91a. On the top side of the diffraction grating holder 91, a first recess 91c cut out in a valley shape is formed on the substrate 91a side, and a second recess 91d cut out in a valley shape is also formed on the folded plate 91b side. Is formed. Thus, it can be said that the board | substrate 91a and the folding | turning board 91b have formed the notch part (1st recessed part 91c and 2nd recessed part 91d) so that it may mutually overlap.

  Here, the first concave portion 91c and the second concave portion 91d are formed by two oblique sides 91c1 and 91c1 and oblique sides 91d1 and 91d1, respectively, but the second concave portion 91d on the folded plate 91b side is formed. Is located deeper than the first recess 91c on the substrate side, and the hypotenuses 91c1 and 91c1 and the hypotenuses 91d1 and 91d1 do not intersect. In other words, the first recess 91c on the substrate 91a side is a shallower recess than the second recess 91d on the folded plate 91b side.

In this case, as shown in FIG. 10, when the adjustment bit 41 is pressed toward the valley bottoms of the first recess 91c and the second recess 91d, the tip of the adjustment bit 41 is the bottom of the shallow first recess 91c. Pressed against.
Although the V-shaped valley bottom is formed by using a mold, it is inevitable that a minute R is generated due to its accuracy. The adjustment bit 41 presses the tip against the bottom of the valley and moves the diffraction grating holder 91 in the width direction, thereby turning the support projection 92 on the lower side as a fulcrum to adjust the angle. Although the tip of the adjustment bit 41 is sharpened in order to adjust with high precision, even if the tip is sharpened, it is pushed and R is generated at the bottom of the valley.

  In other words, when the diffraction grating is adjusted in this manner, the adjustment bit is brought into contact with a part (diffraction grating holder: diffraction grating spring) holding the diffraction grating (diffraction grating element) at a position away from a fulcrum, Although the rotation of the diffraction grating spring is adjusted, the shape of the portion where the adjustment bit of the diffraction grating spring contacts is V-shaped, and since the bottom of V has a minute R on the mold, the adjustment bit is displaced, It cannot be adjusted linearly.

Reference is now made to the geometry of the present invention of FIGS.
As shown in the figure, on the top side of the substrate 31a and the folded plate 31b (formed by hemming from the bottom side to the top side), the substrate 31a side is cut into a roughly valley shape as before the improvement. A cut-out first recess 31c is formed, and a second recess 31d cut out in a substantially valley shape is also formed on the folded plate 31b side. However, unlike the one before the improvement, the second recess 31d on the folded plate 31b side and the first recess 31c on the substrate side have substantially the same depth to the valley bottom, and the positions of the valley bottoms are in the width direction. It is formed so as to overlap. That is, for the first recess 31c, the left side is called the hypotenuse 31c1L and the right side is called the hypotenuse 31c1R, and for the second recess 31d, the left side is called the hypotenuse 31d1L and the right side is the hypotenuse When referred to as 31d1R, as shown in an enlarged view in FIG. 3, the right oblique side 31d1R of the second recess 31d and the left oblique side 31c1L of the first recess 31c intersect each other. Since the edges of the straight hypotenuses intersect each other, there is no room for the slight R generated by a mold or the like at the intersecting portion.

For this reason, when the adjustment bit 41 having a sharp tip is brought into contact with the intersection of the hypotenuse 31d1R and the hypotenuse 31c1L, there is no room for shifting in the width direction. Accordingly, accuracy is improved and linear adjustment is possible.
In this embodiment, the top side corresponds to the overlapping side, the first recess 31c and the second recess 31d correspond to the cut portion, and the hypotenuse 31d1R and the hypotenuse 31c1L, which are substantially linear edges, intersect each other. To form an intersection.

(Second embodiment)
FIG. 4 shows the diffraction grating holder according to the second embodiment in a front view, and FIG. 5 shows the diffraction grating holder according to the second embodiment in a partially enlarged front view.
The diffraction grating holder 51 of the second embodiment is different from that of the first embodiment in the overlapping of the first concave portion 51c and the second concave portion 51d on the top side.
More specifically, the first concave portion 51c has a substantially valley shape having substantially symmetrical oblique sides 51c1L and 51c1R, while the second concave portion 51d has a left oblique side 51d1L having a substantially similar inclined side. The right oblique side 51d1R is formed substantially vertically. The substantially vertical hypotenuse 51d1R on the side of the folded plate 51b intersects with the hypotenuse 51c1L on the left side of the substrate 51a in the middle to form an intersecting portion. At the intersecting portion, at least the angles may intersect with each other.

In both the first embodiment and the second embodiment, the edges forming the intersecting portions are both linear, but need not be exactly linear. This is because there is no room for R to occur at the intersections even if the curved edges are crossed. Even when the arc-shaped cut portions are shifted and overlapped, an intersecting portion can be formed. A combination in which one is a square recess and the other is a valley recess is also possible.
Also in this embodiment, the hypotenuse 51d1R and the hypotenuse 51c1L, which are substantially linear, intersect to form an intersection, and there is no room for R to occur at the intersection. Since one side is nearly vertical, it is necessary that one end of the adjustment bit 42 is also vertical.
That is, the relationship between the tip angle of the adjustment bit and the opening angle of the notch portion of the diffraction grating holder is
(Adjustment bit tip angle C) <(Diffraction grating holder opening angle D)
Should be.

(Third embodiment)
FIG. 6 is a perspective view of the vertically folded diffraction grating holder in the first embodiment, and FIG. 7 is a perspective view of the horizontally folded diffraction grating holder in the present embodiment.
In order to form an overlapping side at the top side, in the first embodiment, the folded plate 31b is folded upward from the lower side of the substrate 31a.

However, it is not always necessary to fold back from the lower side, and as shown in the present embodiment, the substrate 61a and the folded plate 61b are folded in two on the side, and the two first sides formed on the overlapping side composed of the top sides. It is possible to form an intersection part at the edge of the recess 61c and the second recess 61d. In other words, the folded part of the hemming bending can be folded from any part of the peripheral side having a substantially frame shape.
In the present invention, one sheet metal is folded to reduce the number of parts. However, it is naturally included in the scope of the present invention that two sheet metals are stacked and fixed to avoid the invention.

FIG. 8 is a side view showing the relationship between the width of the adjustment tool and the folding width of the diffraction grating holder. The figure (a) illustrates the case where both ends are exactly overlapped by hemming bending, and the figure (b) illustrates the case where the both ends are not exactly overlapped but a gap is formed. ing.
The relationship between the thickness of the adjustment bit 41 and the thickness of the diffraction grating holder 71 is
(Thickness A, A ′ of adjustment bit 41)> (Thickness B, B ′ of diffraction grating holder 71)
It is necessary to become.
In FIG. 8A, A> B, and in FIG. 8B, A ′> B ′.
This is because with such a thickness, the tip of the adjustment bit 41 reliably contacts the edge of the substrate side and the folded plate side. Strictly speaking, if the clearance is larger than the gap between the substrate and the folded plate, the tip of the adjustment bit 41 contacts the substrate and the folded plate, but may be detached from one side when moved during adjustment. It is preferable to maintain the above-described thickness relationship.

  As described above, when the diffraction grating spring (diffraction grating holder) holding the diffraction grating is folded back (hemming bending), the valley-shaped V shape that is the receiving of the adjustment bit is not Cross section, one side is the one that is folded back (the V shape of the valley shape is shifted to the left and right), the bottom of the V shape becomes an acute angle (R is not attached), and the movement of the adjustment bit The diffraction grating spring moved linearly.

  As a result, in the optical pickup having a photodetector (PD) that receives light reflected from the semiconductor laser and enters the optical disk and generates an electrical signal, the holder holding the optical component is A mechanism that can be easily moved can be provided.

Needless to say, the present invention is not limited to the above embodiments. It goes without saying for those skilled in the art,
-Applying the combination of the mutually replaceable members and configurations disclosed in the above-described embodiments as appropriate-The above-described embodiments are not disclosed in the above-described embodiments, but are publicly known techniques. The members and structures that can be mutually replaced with the members and structures disclosed in the above are appropriately replaced, and the combination is changed and applied. It is an embodiment of the present invention that a person skilled in the art appropriately replaces the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments, and changes the combination to apply. It is disclosed as.

DESCRIPTION OF SYMBOLS 11 ... Light emitting element, 12 ... Diffraction grating, 13 ... Half mirror, 14 ... Polarizing beam splitter, 15 ... Collimator lens, 16 ... Launching mirror, 17 ... Wave plate, 18 ... Objective lens, 19 ... Hologram, 20 ... Light receiving element, DESCRIPTION OF SYMBOLS 21 ... Light emitting element, 22 ... Launch mirror, 23 ... Wave plate, 24 ... Objective lens, 25 ... Front monitor, 31 ... Diffraction grating holder, 31a ... Substrate, 31b ... Folding plate, 31c ... First recessed part, 31c1L, 31c1R ... hypotenuse, 31d ... second recess, 31d1L, 31d1R ... hypotenuse, 32 ... support projection, 33 ... contact recess, 41, 42 ... adjustment bit, 51 ... diffraction grating holder, 51a ... substrate, 51b ... folding plate, 51c: first recess, 51c1L, 51c1R ... hypotenuse, 51d ... second recess, 51d1L, 51d1R ... hypotenuse, 61a ... substrate 61b ... folded plate, 61c ... first recess, 61d ... second recess, 71 ... diffraction grating holder, 91 ... diffraction grating holder, 91a ... substrate, 91b ... folded plate, 91c ... first recess, 91c1 ... hypotenuse 91d ... second recess, 91d1 ... slope, 92 ... support projection, 93 ... contact recess.

Claims (5)

A diffraction grating holder for holding a diffraction grating in an optical pickup,
A holder main body formed in a substantially frame shape with sheet metal;
An overlapping side formed so that sheet metal overlaps on one side by folding a part of the holder main body,
A diffraction grating holder characterized in that, in each sheet metal that overlaps at overlapping sides, a cut portion is formed so as to overlap each other, and an intersection portion where substantially linear edges of each cut portion intersect is formed.   2. The diffraction grating holder according to claim 1, wherein the cut portions overlapping each other are each formed in a substantially valley shape, and are overlapped so that the bottom of the valley is shifted.   The cut portions that overlap each other have at least edges that intersect each other, and the edges intersect to form the intersecting portions. The diffraction grating holder as described.   The said overlapping side is formed so that the top sides may overlap each other when the side portion of the main body portion is folded back when the cut portion is formed on the top side of the main body portion. 4. The diffraction grating holder according to any one of 3.   The overlapping side is formed so as to overlap the top side by folding the bottom side of the main body part to the top side when the cut portion is formed on the top side of the main body. Item 4. The diffraction grating holder according to any one of Items 3.

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