JP4276919B2 - Optical element molding apparatus and molding method - Google Patents

Description

  The present invention relates to a molding apparatus and a molding method for molding optical elements such as lenses and prisms by heating and pressing an optical glass material.

  In the molding of optical elements, the upper and lower molds facing each other are inserted into a body mold, and the upper and lower molds are slid in the body mold to perform press molding. A conventional molding apparatus having such a structure is disclosed in JP-A-7-2535.

In this conventional molding apparatus, an upper die and a lower die sandwiching an optical glass material are slidably inserted into a barrel die so that the upper and lower die optical axes are aligned with each other. It is structured to be installed in between. In addition to this, a cylinder-type fixing head is provided which clamps and fixes the cylinder mold. In a molding apparatus having such a structure, when the temperature reaches a temperature at which the optical glass material can be deformed by heating, the barrel mold fixing head sandwiches the barrel mold to regulate the position of the barrel mold, and then moves the upper mold. The optical glass material is pressed and deformed to mold the optical element.
Japanese Patent Laid-Open No. 7-2535

  In the above-described conventional molding apparatus, the inner surface of the barrel mold and the outer surfaces of the upper and lower molds are in contact with each other, and the upper and lower molds (upper mold) slide in the barrel mold in this contact state. That is, the upper and lower molds are sandwiched between the upper and lower molds so that the clearance is zero, and since both the upper and lower molds are formed of a rigid body, the contact portions of these are inevitably worn. When this wear occurs, the roundness is lost, so it becomes difficult to align the optical axes of the upper and lower molds, and the molds must be replaced.

To prevent such wear, it has been made to provide a clearance of about 1~3μm between the upper and lower molds and the body mold, in this case, the direction intersecting orthogonally-shaped and the pressing direction of the forming A shift shift that shifts and a tilt shift that shifts in a direction inclined with respect to the press direction easily occur between the upper and lower molds. When these deviations occur, the accuracy of the optical element to be molded decreases.

  Further, it is structurally difficult to prevent such shift and tilt shifts with respect to a clearance of about 1 to 3 μm. However, when a mechanism for preventing these shifts is incorporated in a molding apparatus, the molding apparatus A new problem arises that makes the entire system complicated and difficult to control.

  The present invention has been made in consideration of such conventional problems, and the upper and lower optical axis alignment by the barrel mold can be easily performed without causing wear, and the optical element can be molded. An object of the present invention is to provide a molding apparatus and a molding method for an optical element capable of performing the above with high accuracy.

The apparatus for molding an optical element of the invention of claim 1 is a molding apparatus for forming an optical element by heating and softening an optical glass material, and a pair of substantially cylindrical shapes for pressing the heat-softened optical glass material. A mold, a deformable body mold having an inner peripheral surface approximate to the outer peripheral surface of the mold, into which the mold is inserted, and the pair of molds are brought into contact with the inner surface of the body mold and positioned. Therefore, and a deformation means for deforming in the intersecting direction with respect to the optical axis body mold in a state movable in a direction intersecting the optical axis is within the barrel die pair of molds, the deforming means Further, it is characterized by comprising at least a pressing member that presses the body mold from the outside .

  According to the first aspect of the present invention, the pair of molding dies are inserted into the barrel mold, and in this state, the barrel mold is deformed in a direction intersecting the optical axis by the deformation means. Due to this deformation, the pair of molds abut against the inner surface of the barrel mold. Since the inner peripheral surface of the barrel mold approximates the outer peripheral surface of the pair of molds, the pair of molds follow the inner peripheral surface of the barrel mold and is in a positioning state in which the optical axes are aligned.

  In such an invention of claim 1, since the barrel mold is deformed in the direction intersecting the optical axis, the pair of molding dies are brought into contact with the inner surface of the mold so that a shift deviation and a tilt deviation may occur. The pair of molds can be positioned with high accuracy with a simple structure. For this reason, an optical element can be shape | molded with high precision.

  A second aspect of the present invention is the optical element molding apparatus according to the first aspect, wherein the body mold has a plurality of spaces into which a pair of molding dies can be inserted.

  In the invention of claim 2, a large number of optical elements can be simultaneously molded by inserting a molding die into a plurality of spaces of the barrel die.

An optical element molding method according to a third aspect of the present invention is a molding method in which an optical glass material is heated and softened to form an optical element. The inner circumferential surface approximates to the outer circumferential surface of a pair of substantially cylindrical molds. A step of inserting a pair of molds and an optical glass material into a deformable cylinder mold having a shape, and the pair of molds is movable in a direction intersecting the optical axis in the cylinder mold. A step of deforming in a direction intersecting the axis and positioning the pair of molds in contact with the inner surface of the body mold; and a step of molding the optical glass material by pressing the pair of molds. Yes, and the positioning step is characterized by deforming the the barrel type by pressing the barrel die from the outside.

  In the invention of claim 3, after inserting the pair of molds holding the optical glass material into the barrel mold, in the positioning step, the barrel mold is deformed in a direction intersecting the optical axis, and the inner surfaces thereof are paired. Contact the mold. At this time, since the inner peripheral surface of the barrel mold approximates the outer peripheral surface of the pair of molds, the pair of molds follow the inner peripheral surface of the barrel mold by contacting the barrel mold. As a result, the optical axes are aligned and no shift deviation or tilt deviation occurs, and the pair of molds can be positioned with high accuracy by a simple operation.

  The invention of claim 4 is the optical element molding method according to claim 3, wherein the body mold has a plurality of spaces into which a pair of molds can be inserted, and the positioning step includes a plurality of pairs. The molds are positioned at the same time.

  In the invention of claim 4, since a plurality of pairs of molds are simultaneously positioned, a large number of optical elements can be molded.

  A fifth aspect of the present invention is the optical element molding method according to the third or fourth aspect, wherein the positioning step is performed immediately before the end of pressing with a pair of molding dies.

  The optical element is molded by pressing an optical glass material with a pair of molds. In the invention of claim 5, the positioning step by the deformation of the body mold is performed immediately before the end of the press, and the optical element is molded with the optical axes of the pair of molds aligned immediately before the end of the press. In such an invention, since the contact of the barrel mold with the pair of molds is short, the sliding distance between the mold and the barrel mold is shortened. For this reason, the abrasion by sliding can be suppressed.

  According to the optical element molding apparatus of the present invention, since the barrel mold is deformed in a direction intersecting the optical axis, the pair of molding dies are brought into contact with the inner surface of the mold so that the shift deviation and tilt can be achieved with a simple structure. Generation | occurrence | production of deviation | shift can be prevented and a pair of shaping | molding die can be positioned with high precision.

  According to the method for molding an optical element of the present invention, the barrel mold is deformed and the inner surfaces thereof are brought into contact with the pair of molds, so that the pair of molds are positioned and the occurrence of shift shift and tilt shift is prevented. Therefore, the pair of molds can be positioned with high accuracy by a simple operation.

  Hereinafter, the present invention will be specifically described with reference to embodiments shown in the drawings. In each embodiment, the same members are assigned the same reference numerals.

(Embodiment 1)
1 to 3 show a first embodiment of the present invention, and FIG. 1 shows an overall front view. An optical element molding apparatus 1 according to this embodiment includes an upper mold 2 and a lower mold 3 as a pair of molding molds, a trunk mold 4 into which these molds 2 and 3 are inserted facing each other, and a trunk mold 4. A pressing member 5 and a receiving member 6 are provided as deformation means for deforming. The optical glass material 10 is subjected to press molding while being sandwiched between the lower mold 3 and the upper mold 2.

  The body 4 having the upper mold 2 and the lower mold 3 inserted therein is molded on the optical glass material 10 while being placed on the lower mold heater plate 7. The lower die heater plate 7 is attached to the upper surface of the lower die heater 8 supported by the lower shaft 9. On the other hand, the upper mold heater plate 11 is disposed so as to contact the upper mold 2. The upper heater plate 11 is attached to the lower surface of the upper heater 12 attached to the upper shaft 13. The upper shaft 13 applies a pressing force along the arrow B direction parallel to the optical axis, whereby the upper mold 2 moves in the lower mold 3 direction, and the optical glass material 10 is press-molded.

  As the pressing member 5 which is one constituent member of the deformation means, a cylinder is used which extends and operates along the direction of the arrow A that intersects the optical axis perpendicularly. The pushing member 5 extends the rod 5a in the direction of the barrel die 4 by its extension operation, and deforms the barrel die 4 in the direction of the arrow A intersecting at right angles to the optical axis. On the other hand, the receiving member 6, which is another constituent member of the deforming means, is disposed at a position sandwiching the body mold 4 with the pressing member 5, so that the body mold is deformed based on the extension of the pressing member 5. Works.

  FIG. 2 shows the positional relationship between the body mold 4, the pressing member 5, and the receiving member 6. The body mold 4 has such a length that the upper mold 2 and the lower mold 3 holding the optical glass material 10 can be inserted. The body mold 4 is composed of a pair of semicircular divided bodies 4a and 4b obtained by dividing a circle into two equal parts when viewed from the plane. Each of the divided bodies 4a and 4b is formed in a substantially Ω shape, and insertion portions 4c and 4d into which the upper die 2 and the lower die 3 are inserted, and arms extending in the radial direction from both ends of the insertion portions 4c and 4d It is comprised by the parts 4e and 4f.

  The upper mold 2 and the lower mold 3 are formed in a substantially cylindrical shape, and are positioned so that the optical axes thereof coincide with each other when inserted into the insertion portions 4 c and 4 d of the trunk mold 4. The inner peripheral surfaces 14 and 15 of the insertion portions 4c and 4d of the body mold 4 are formed in a shape approximately similar to the outer peripheral surfaces of the upper mold 2 and the lower mold 3, and the outer peripheral surfaces of the upper mold 2 and the lower mold 3 are The upper die 2 and the lower die 3 are positioned by abutting. The arm portions 4e and 4f provided at both ends of the insertion portions 4c and 4d receive a pressing force by the pressing member 5.

  The tip of the rod 5a of the pressing member 5 is bifurcated, and each tip faces the arm 4e of one divided body 4a. The receiving member 6 is also branched in a bifurcated manner, and receives the arm portion 4f in a state where the tip end portion is in contact with the arm portion 4f of the other divided body 4b.

  Next, molding of the optical element according to this embodiment will be described. As shown in FIG. 1, the upper mold 2 and the lower mold 3 sandwiching the optical glass material 10 are inserted into the body mold 4 to be in an assembled state, and placed on the lower mold heater plate 7 in this assembled state.

  FIG. 2 shows this state, in which the divided bodies 4a and 4b of the body mold 4 wrap around the upper mold 2 and the lower mold 3. In this state, the upper mold 2 and the lower mold 3 are in close contact with each other. Absent. Therefore, the upper mold 2 and the lower mold 3 can freely move in the direction of the arrow B along the optical axis, and can be pressed.

After the upper heater plate 11 and being in contact with the upper mold 2, the lower mold 3 by a heater 8,12 of, respectively it, the upper mold 2 to heat the barrel die 4. By this heating, the optical glass material 10 sandwiched between the upper mold 2 and the lower mold 3 is heated.

  When the optical glass material 10 is heated to a predetermined temperature at which it can be molded, the upper and lower heater plates 11 and 7 are relatively brought closer by driving the upper shaft 13 and the lower shaft 9. Thereby, pressing of the optical glass material 10 by the upper mold 2 and the lower mold 3 is started.

  When the optical glass material 10 is gradually deformed by the press and immediately before the end of the press, the pressing member 5 is driven to press the rod 5a against the arm portion 4e of the divided body 4a to apply the deformation force. Due to this pressing force, the divided body 4a moves in the direction of the arrow A intersecting perpendicularly to the optical axis, that is, in the direction of the divided body 4b. Since the divided body 4b is supported by the receiving member 6, it does not move, so that the divided body 4a is received by the divided body 4b.

  FIG. 3 shows a state in which the pressing member 5 is further driven, and the arm portions 4e and 4f are sandwiched between the receiving member 6 and the rod 5a of the pressing member 5. From this state, the distance between the arm portions 4e and 4f is further increased. Move in the direction of decreasing. As a result, the body mold 4 is deformed so as to have a smaller diameter, and the inner peripheral surfaces 14 and 15 abut against the upper mold 2 and the lower mold 3. At this time, since the inner peripheral surfaces 14 and 15 of the trunk mold 4 are approximate to the outer peripheral surfaces of the upper mold 2 and the lower mold 3, the upper mold 2 and the lower mold 3 are connected to the inner peripheral surfaces 14 and 15 of the trunk mold 4. In a copied state, positioning with the optical axis aligned is performed. After this positioning, pressing is continued further, so that pressing is performed by the upper mold 2 and the lower mold 3 in which the optical axes are aligned.

Then, after the end of the press, the upper and lower molds of heater motor 1 2,8 and OFF, after cooling, to raise the upper heater plate 11, the upper mold 2, the lower heater plate the lower mold 3 and the barrel die 4 Remove from 7.

  In such an embodiment, the barrel mold 4 is deformed in the direction A intersecting the optical axis, and the upper mold 2 and the lower mold 3 are brought into contact with the inner peripheral surfaces 14 and 15 for positioning. Tilt displacement does not occur. For this reason, the upper mold | type 2 and the lower mold | type 3 can be positioned with high precision, and an optical element can be shape | molded with high precision. Further, a complicated structure for preventing shift shift and tilt shift is unnecessary, and control is also easy.

  Further, in this embodiment, since the positioning performed by deforming the body mold 4 is performed immediately before the end of pressing the optical glass material 10, the contact between the upper mold 2 and the lower mold 3 and the body mold 4 is short. Therefore, the sliding distance between the upper mold 2 and the lower mold 3 and the trunk mold 4 is shortened. For this reason, wear of the upper mold 2, the lower mold 3, and the trunk mold 4 due to sliding can be suppressed.

  In this embodiment, prior to pressing the optical glass material 10 by the upper mold 2 and the lower mold 3, the pressing member 5 is driven to position the upper mold 2 and the lower mold 3 by the barrel mold 4. May be. Further, the pressing by the upper mold 2 and the lower mold 3, the positioning of the upper mold 2 and the lower mold 3 by the contact of the body mold 4, and the release of the contact of the body mold 4 by stopping the driving of the pressing member 5 are repeated. May be performed. Further, during pressing by the upper mold 2 and the lower mold 3, molding may be performed by controlling the contact force with respect to the upper mold 2 and the lower mold 3 of the body mold 4 in a stepwise manner.

As described above, since the deformed in a direction barrel die 4 intersects the optical axis, the barrel die 4 easily deformable material is used. As this material, ceramics such as silicon carbide (SiC), silicon nitride (SiN ₄ ), aluminum nitride (AlN), zirconia (ZrO ₂ ), and cermet having a large Young's modulus can be used. It is also possible to use steel materials such as. Also, it is possible to use super hard (tungsten carbide).

(Embodiment 2)
4 and 5 show the body mold 20 according to the second embodiment of the present invention. 4 is formed in a substantially circular shape when viewed from above, and a main body 21 into which the upper mold 2 and the lower mold 3 are inserted, and a pair of arm sections 22 extending in the radial direction from the end of the main body 21. , 23. The receiving member 6 contacts the arm portion 23, and the rod 5a of the pressing member 5 faces the arm portion 22. In this embodiment, the rod 5a presses the arm portion 22 in the direction of the arrow A and approaches the arm portion 22 direction, thereby reducing the diameter of the main body 21. Thereby, the inner surface of the main body 21 abuts on the outer peripheral surfaces of the upper mold 2 and the lower mold 3 inserted into the main body 21, and the upper mold 2 and the lower mold 3 can be positioned.

  The body mold 20 in the form shown in FIG. The thick portion 25 is formed so as to be located on the opposite side of the pair of arm portions 22 and 23. By providing the thick portion 25 in this way, there is an advantage that the main body 21 can be made into a perfect circle when the diameter of the main body 21 is reduced.

(Embodiment 3)
FIG. 6 shows a trunk mold 30 according to the third embodiment of the present invention. The body mold 30 has four spaces 31 into which the upper mold 2 and the lower mold 3 are inserted. The spaces 31 are arranged radially from the center of the trunk mold 30 at equal intervals. Each space 31 has an inner peripheral surface that approximates the outer peripheral surfaces of the upper mold 2 and the lower mold 3. Further, a part of the space is opened, and the arm portion 32 extends in the radial direction from the opened portion. The arm portion 32 moves in the closing direction indicated by the arrow D when the force in the arrow A direction by the pressing member 5 acts. The direction of arrow D is a direction that intersects the optical axis. By such movement, the space 31 is deformed so as to be closed, and the inner surface comes into contact with the outer peripheral surfaces of the upper mold 2 and the lower mold 3 inside. Thereby, the upper mold | type 2 and the lower mold | type 3 can be positioned.

  In this embodiment, since there are four spaces 31 into which the upper mold 2 and the lower mold 3 are respectively inserted, the upper mold 2 and the lower mold 3 can be positioned simultaneously in the respective spaces 31. it can. Thereby, many optical elements can be shape | molded simultaneously.

(Embodiment 4)
FIG. 7 shows a fourth embodiment of the present invention. In this embodiment, the receiving member 40 is formed in a block shape, and arc-shaped receiving surfaces 41 are formed at four locations on the outer surface portion thereof. A barrel die 35 into which the upper die 2 and the lower die 3 are inserted is set on each receiving surface 41. Therefore, also in this embodiment, it is possible to mold a large number of optical elements at the same time.

  The trunk mold 35 has a shape in which a part of a circle is cut out, and is set in the receiving surface 41 in an arbitrary direction. With respect to this set state, the pressing member 5 approaches the receiving member 40 and abuts on the body mold 35 in the receiving surface 41. By this abutment, the body die 35 is deformed in a direction in which the diameter decreases, and abuts against the inner upper die 2 and the lower die 3 to position them.

  The pressing member 5 has a structure that can be swung as shown by an arrow G, so that the pressing member 5 can simultaneously abut against a plurality of corresponding barrel molds 35 and simultaneously reduce the diameter of the plurality of barrel molds 35. It can be carried out.

  The present invention can be variously modified without being limited to the above embodiments. For example, the inner surface of the body mold only needs to have an arc length that contacts the upper mold 2 and the lower mold 3 to position them, and for this purpose, if the arc mold has a semicircular or longer arc length, It is possible to select appropriately.

It is a whole front view of the shaping | molding apparatus in Embodiment 1 of this invention. FIG. 3 is a plan view before positioning of the trunk mold using the first embodiment. It is a top view after positioning of a trunk mold. It is a top view of the trunk | drum type | mold in Embodiment 2 of this invention. FIG. 10 is a plan view of another trunk mold according to the second embodiment. FIG. 10 is a plan view of a trunk mold in the third embodiment. FIG. 10 is a plan view of a trunk mold in the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding apparatus 2 Upper mold | type 3 Lower mold | type 4, 20, 30, 35 Body type | mold 5 Pressing member 6 Receiving member 10 Glass optical material

Claims (5)

In a molding apparatus that forms an optical element by heating and softening an optical glass material,
A pair of substantially cylindrical molds for pressing the heat-softened optical glass material;
A deformable body mold having an inner peripheral surface that approximates the outer peripheral surface of the mold and into which the mold is inserted;
In order to position the pair of molds in contact with the inner surface of the barrel mold, the barrel mold is moved with respect to the optical axis in a state in which the pair of molds can move in the direction intersecting the optical axis within the barrel mold. Deforming means for deforming in the intersecting direction ,
The apparatus for molding an optical element, wherein the deformation means comprises at least a pressing member that presses the body mold from the outside .   The optical element molding apparatus according to claim 1, wherein the barrel mold includes a plurality of spaces into which a pair of molding dies can be inserted. In the molding method to make the optical element by heating and softening the optical glass material,
Inserting the pair of molds and the optical glass material into a deformable body mold having an inner peripheral surface that approximates the outer peripheral surface of the pair of substantially cylindrical molds;
While the pair of molds are movable in the direction intersecting the optical axis in the barrel mold, the barrel mold is deformed in the direction intersecting the optical axis, and the pair of molds are brought into contact with the inner surface of the barrel mold Positioning step for positioning,
Have a, a step of forming by pressing by the optical glass material of the pair of molds,
In the positioning step, the body mold is deformed by pressing the body mold from the outside .   The optical element according to claim 3, wherein the barrel mold has a plurality of spaces into which a pair of molding dies can be inserted, and the positioning step simultaneously positions the plurality of pairs of molding dies. Molding method.   5. The method of molding an optical element according to claim 3, wherein the positioning step is performed immediately before the end of pressing with a pair of molds.

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