KR100726506B1 - Optical element molding apparatus and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a mold press molding apparatus for simultaneously press molding a plurality of molding materials by means of a molding mold, the pressure sensor detecting the number of molding materials adsorbed by the adsorption pad of the preform supply device, and the molding mold being driven. Drive means for press molding, and a drive control means for selecting a press load based on the number of detected molding materials and driving the drive means in accordance with the selected press load.

Description

Optical device molding apparatus and manufacturing method therefor {OPTICAL ELEMENT MOLDING APPARATUS AND METHOD FOR MANUFACTURING THE SAME}

1 is a plan view schematically showing an embodiment of a mold press molding apparatus to which the present invention is applied.

2 is a view schematically showing an example in which a pressure sensor is installed in a molding material supply apparatus using a pressure sensor as a detection means of a molding material.

3 (a) and 3 (b) schematically show an example in which the optical sensor is provided on the side of the lower mold by using the optical sensor as the detection means of the molded material.

4 (a) and 4 (b) are explanatory diagrams when detecting the presence or absence of a molding material with an optical sensor.

5 is a block diagram schematically showing the configuration of the control means.

Explanation of symbols on the main parts of the drawings

10: manufacturing apparatus of glass optical element 20: heating chamber

22: preform supply device 23: preform conveying device

24: preform heating device 40: molding chamber

41: press device 42: apparatus for carrying out glass optical elements

43: extraction preparation room 50: control means

221: suction pad 222: vacuum pump

223: suction path 224: pressure sensor

420: lower mold 421: optical sensor

The present invention is a mold for forming an optical element (lens, etc.) by heat-softening a plurality of molding materials (preformed preforms, etc.) in a manufacturing process such as an optical element, and press molding with a molding mold. The present invention relates to a press molding apparatus and a manufacturing method of an optical element.

When a molded material, such as a glass material, in a heat-softened state is press-molded in a molding mold which is precisely processed into a predetermined shape and heated to a predetermined temperature, and the molded surface is transferred to the glass material, optical having high surface precision and shape accuracy is achieved. A device can be obtained.

In this case, in order to improve the production efficiency, a method of simultaneously press molding a plurality of glass optical elements using a plurality of molding molds has been proposed (for example, Japanese Patent Application Laid-Open No. 11 (1999) -29333 (hereinafter referred to as "Patent Formation"). , Referred to as 'Patent Document 1').

In the press method described in Patent Document 1, a plurality of molding molds are arranged in a line in a straight line, and induction heating is caused from both sides, so that each molding mold can be uniformly heated to perform press molding. As a result, a glass optical device having high surface precision and good surface quality can be obtained without causing problems such as partial elongation.

However, in the molding apparatus described in Patent Document 1, the same number of glass preforms are not always supplied to the mold in the molding step. For example, when the glass preform in the material supply tray disappears during continuous pressing, a suction error (error) of the glass preform caused by the adsorption pad occurs, or a supply error of the glass preform to the mold occurs. In the press, the number of glass preforms disposed in the molding mold is smaller than the normal number.

In press molding of an optical element, the press load is optimally adjusted based on the number of glass preforms to be placed in the mold. Therefore, if the number of the preforms arranged is less than the regular number, the press load applied per glass preform becomes large.

In the precision mold press, the management of the press load is very important for achieving the surface precision and the precision of the lens thickness. In particular, in press forming of concave meniscus lenses, convex meniscus lenses, or biconcave lenses, the load schedule in the initial press or subsequent additional presses If the load schedule in the cooling process is not properly controlled, the surface precision and the thickness of the lens may deviate from the values (specifications) for achieving the desired optical performance.

In addition, in the apparatus which controls a press schedule according to the time after press start, when the preform is pressed in the state less than a normal number, the time required for straining a predetermined amount of glass becomes short. For this reason, the cycle operation of the molding apparatus is disturbed. In addition, when the hot preform is pressed by a mold having a lower temperature, if the time required to deform a predetermined amount of glass is short, the initial press is terminated while the temperature of the preform is higher than normal, Since the process shifts to the cooling process, the molding conditions change and abnormality occurs in the lens thickness.

Accordingly, the present invention has been made in view of the problems of the prior art, the object of which is the number of glass preforms disposed in the mold due to the supply error of the glass preforms, etc. when pressing a plurality of glass preforms at once The present invention provides a molding apparatus for an optical element and a method of manufacturing the same, in which an optical element having a desired thickness and surface precision can be obtained even when the? Is changed.

In order to achieve the above object, the molding apparatus of the present invention is a molding apparatus for press-molding a plurality of molding materials at the same time by a molding mold, the molding material detecting means for detecting the number of the molding material to be press-molded; And a drive control means for driving the molding mold by press molding and selecting a press condition based on the number of the detected molding materials and driving the drive means in accordance with the selected press condition. .

With such a configuration, since the molding can be performed under the press condition corresponding to the number of the molding materials detected, an optical element having excellent surface precision and thickness precision can be obtained.

Here, the number of molded materials does not mean simply the number of molded materials, but also includes the amount of detection signals corresponding to the number of molded materials output by the detection means.

In the present invention, the press condition may be any one of a press load, a press amount, a press time, a press speed, or a combination of two or more.

Here, the "press load" is a load for pressing the molding mold in which the molding material is accommodated, and includes a load when pressing in multiple stages.

In addition, the "press amount" means the quantity (size) which relatively closes a pair of press means which apply a load to the opposing molding mold (for example, upper mold and lower mold).

In addition, the "press time" means the time when the shaping | molding mold is pressurized with a press means, and the time when the press means is relatively close, and when it stops in the state which applied the appropriate load to the shaping | molding mold, Include.

In addition, a "press speed" means the speed at the time of pressurizing a molding mold with a press means.

With the above structure, an optical element with high precision can be obtained by changing one or more press conditions among the press load, the press amount, the press time, and the press speed in response to the change in the number of molded materials.

In addition, the present invention can be configured to select a press load based on the number of the molded materials detected as the press condition, and to drive the driving means in accordance with the selected press load.

Further, the present invention has a configuration in which the drive control means selects the press stop position based on the number of the detected molding materials or the selected press load, and drives the drive means in accordance with the selected press stop position.

With such a configuration, when the thickness of the glass optical element fluctuates slightly as the amount of elastic deformation of the press apparatus accompanying the change of the press load changes, the fluctuation can be corrected and a higher precision optical element can be obtained. .

Further, in the present invention, when the molded material is sucked and held by the suction supply means, a pressure detecting means is provided in the suction path of the suction supply means, and the pressure detecting means detects the number of the supplied molding materials. It becomes the structure to say. In this case, a suction path of the suction supply means may be formed for each of the plurality of molded materials, and pressure detection means may be provided for each of the plurality of suction paths.

With such a configuration, it is possible to detect a supply error of the molded material generated when the molded material is supplied or conveyed by the adsorption pad, and to perform molding by press load or the like based on the number of the supply materials.

In addition, the number of molded materials can be detected by performing suction on a plurality of suction pads in one suction path and preliminarily obtaining a relationship between the pressure value in the suction path and the number of molded materials. have.

In these cases, the number of molded materials detected is a specific number derived as a result of judging the presence or absence of the molded material based on the signal amount corresponding to the detected pressure from the pressure sensor and the signal amount.

In addition, the present invention may be arranged so that the optical detection means for optically detecting the molded material is arranged at a supply position of the plurality of molded materials, and the optical detection means detects the number of the molded material supplied. have.

With such a configuration, the presence or absence of the molding material and the total number of the molded materials can be detected in the non-contact state. In this case, a plurality of optical detection means may be arranged for each of the molded materials to be detected, and the presence or absence of a plurality of molded materials may be detected by one sensor using optical detection means such as a line sensor.

In the case where these optical detection means are used, the number of molded materials detected is derived as a result of judging the presence or absence of the molded material based on the signal amount corresponding to the amount of light detected by the optical sensor and the signal amount as in the case of the pressure sensor. The specific number.

In the method for manufacturing an optical element according to the present invention, by using the molding apparatus described in any one of the above, a molding material which has been softened by heating is produced by press molding.

In addition, in the method for manufacturing an optical element according to the present invention, the press molding step includes an initial press and a second press which presses with a smaller load than the initial press, and the initial press is used as the selected press. This is done by driving the drive means in accordance with the load. In this case, it is preferable to perform the said 2nd press together with cooling.

According to the manufacturing method of such an optical element, even when a plurality of optical elements are manufactured at the same time, since it can be molded by an appropriate press load according to the number of molding materials, an optical element having excellent surface accuracy and shape accuracy can be manufactured. have.

According to the present invention, when pressing a plurality of molding materials at a time, even if the number of molding materials placed in the mold is changed due to the supply error of the molding material, the press load according to the number of molding materials can be applied Therefore, an optical element having a desired thickness and surface precision can always be obtained.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

In addition, below, although this invention is demonstrated according to embodiment applied to the manufacturing apparatus of a glass optical element, the mold press molding apparatus of this invention is not limited to this embodiment, The manufacturing of resin optical element or glass and resin The present invention can also be applied to the manufacture of parts other than optical elements.

1 is a schematic plan sectional view when the mold press molding apparatus according to the present invention is applied to a manufacturing apparatus for a glass optical element.

In the manufacturing apparatus shown in Fig. 1, a spherical glass preform is pressed as a molding material to produce a compact collimator lens. In general, a plurality of spherical glass preforms are simultaneously supplied into a housing of the present apparatus (six in the example in the drawing), and then softened by heating, pressed and cooled by a molding mold, and moved out of the housing. Are taken out. By repetition of this process, a number of collimator lenses are produced in succession.

As shown in FIG. 1, the manufacturing apparatus 10 of the said glass optical element is equipped with the heating chamber 20 and the shaping | molding chamber 40. As shown in FIG. The heating chamber 20 and the shaping chamber 40 are mutually communicated by the passage 60 provided with the on-off valve 61, and are connected to the heating chamber 20, the shaping chamber 40, and the passage 60. As a result, one sealed space is blocked from the outside. The outer wall of the said sealed space is formed of members other than stainless steel, and the airtightness is maintained by the sealing material. The sealed space formed by the heating chamber 20, the shaping chamber 40, and the passage 60 becomes an inert gas atmosphere at the time of shaping the glass optical element. That is, the gas in the space is exhausted by the gas exchange device (not shown), and instead, the inert gas is filled. As the inert gas, it is preferable to use a _{(e.g., N 2 + 0.02vol% H 2} ) or nitrogen gas and nitrogen mixed gas of hydrogen.

The heating chamber 20 is an area for preheating the glass preform G to be supplied prior to pressing. The heating chamber 20 includes a preform supply device 22, a preform conveying device 23, and a preform heating device ( 24) is installed. In addition, a supply preparation chamber 21 for supplying the glass preform G from the outside into the heating chamber 20 is provided.

The supply preparation chamber 21 arrange | positions the glass preform G on a tray, in order to prevent air from flowing into the heating chamber 20, and is sealed and replaced by inert gas atmosphere.

Moreover, six trays (not shown) are arrange | positioned at the supply preparation chamber 21, and six glass preforms G are put here using a robot arm (not shown).

As shown in FIG. 2, the preform supply device 22 provided in the supply preparation chamber 21 has six suction pads 221. These suction pads 221 are provided with six suction paths 223 connected to and in contact with the vacuum pump 222, respectively. Moreover, the pressure sensor 224 is provided in each of these suction paths 223, and the pressure in each suction path 223 is measured. The pressure sensor 224 outputs the measurement result to a controller (drive control means) 50 to be described later in detail.

By the preform supply device 22 having such a configuration, the glass preform G on the tray in the supply preparation chamber 21 is adsorbed and brought into the heating chamber 20. At this time, if any one of the six adsorption pads 221 does not adsorb the glass preform G, the degree of vacuum in the corresponding suction path 223 is lowered, so that the pressure sensor 224 Detects this. The control means 50 detects the position of the adsorption pad 221 which has not adsorbed the glass preform G on the basis of the signal from the pressure sensor 224 and at the same time the whole of the preform supply device 22. The number of glass preforms G adsorbed is detected.

As shown in FIG. 1, the preform conveyance apparatus 23 receives the glass preform G carried in from the supply preparation chamber 21, and conveys it to the heating area | region by the preform heating apparatus 24, and also The heat-softened glass preform G is conveyed to the molding chamber 40. The preform conveyance apparatus 23 is equipped with the six trays 26 at the front-end | tip of the arm 25, and hold | maintains the glass preform G on it.

In this embodiment, the arm 25 provided with the tray 26 is horizontally supported by the drive part 23a fixed in the heating chamber 20, and the arm 25 is horizontally at a rotation angle of about 90 degrees. Is rotated to. Moreover, the arm 25 is comprised so that advancement and retraction are possible in the radial direction centering on the drive part 23a, and conveys the hold | maintained glass preform G to the shaping | molding chamber 40 by this.

The preform conveying apparatus 23 has an arm opening / closing mechanism (not shown) in the driving section 23a, thereby opening the tip of the arm 25 to drop the glass preform G onto the molding mold. .

When the glass preform G is conveyed in a preheated and softened state, if a defect occurs on the glass surface by contacting the conveying jig, the shape accuracy of the optical element after molding is impaired. For this reason, it is preferable that the preform conveyance apparatus 23 is equipped with the floating jig which conveys the glass preform G in the state which carried out the gas floating. For example, it may be possible to support a split mold type floating tray with a detachable arm.

 The preform heating device 24 is for heating the supplied glass preform G to a temperature corresponding to a predetermined viscosity. In order to raise the glass preform G stably to a constant temperature, it is preferable to use a heating device (eg, a Fe—Cr heater) by resistance heating using a resistance element. The preform heating device 24 is roughly "co" shaped from the side, and has a heater member on the upper and lower surfaces inside. As shown in FIG. 1, the preform heating device 24 is provided on a moving trajectory of the glass preform G held on the arm 25.

The arm 25 is placed in the preform heating device 24 except when receiving the glass preform G from the preform supply device 22 and conveying it to the molding chamber 40. The temperature of the heater surface of the preform heating device 24 may be about 1100 ° C, the atmosphere inside the furnace, that is, the atmosphere between the upper and lower heaters may be about 700 ~ 800 ° C. Moreover, in this embodiment, the warpage of the arm 25 in the longitudinal direction is prevented by providing a temperature difference between an up-and-down heater.

On the other hand, the shaping | molding chamber 40 is an area | region for pressing the glass preform G preheated by the said heating chamber 20, and forming the glass optical element of a desired shape. In the shaping chamber 40, the press apparatus 41 and the carrying-out apparatus 42 of a glass optical element are provided. In addition, an extraction preparation chamber 43 for carrying out the press-molded glass optical element to the outside is provided.

The press apparatus 41 simultaneously receives the six glass preforms G conveyed from the heating chamber 20 by the preform conveyance apparatus 23, and presses this, and obtains the glass optical element of a desired shape. The press apparatus 41 is equipped with the upper mold (not shown) and the lower mold 420 (refer FIG. 3), and presses six glass preforms G supplied between them simultaneously by the molding surface. . The six glass preforms G on the arm 25 of the preform conveying device 23 fall on the lower mold 420 by opening the tip of the arm. Then, immediately after the arm is retracted from between the molding molds, the lower mold 420 is raised toward the upper mold, whereby the glass preform G inserted therebetween is pressed. The lower mold 420 is driven by a driving means (servo motor) 51 driven on the basis of the command from the control means 50 to be press-molded by a predetermined distance with a predetermined load (see Fig. 5). ).

As shown in Figs. 3A and 3B, optical sensors 421 are disposed on the side portions of the six lower molds 420 of the press apparatus 41, respectively. The optical sensor 421 is disposed on one side of the lower mold 420 to emit laser light and the like, and is disposed on the other side of the lower mold 420 so that the optical sensor 421 is separated from the transmitter 421a. It consists of a light receiver 421b which receives light. These light projectors 421a and 421b are connected to the control means 50. The control means 50 outputs an operation signal to the light projector 421a, and inputs a measurement signal from the light receiver 421b (see Fig. 5).

According to the optical sensor 421, when there is no glass preform G on the lower mold 420, the light receiver 421b receives the maximum amount of light. On the other hand, if there is a glass preform (G) on the lower mold 420, a part of the light transmitted from the transmitter 421a is reflected on the surface of the glass preform (G), the rest is refracted to form the glass preform (G) Permeate. In this case, since the transmitted light becomes diffused light, the amount of light received by the light receiver 421b can be considerably reduced by dropping the light receiver 421b to some extent from the glass preform G (see FIG. 4). (a)). Particularly due to the shape of the glass preform G, when the light from the light projector 421a is obliquely incident on the glass preform G, the direction of transmitted light is also oblique to further increase the amount of received light at the light receiver 421b. It can reduce, and can cause a large difference in the amount of light received according to the presence or absence of the glass preform (G) (see (b) of Figure 4). Therefore, when the light receiving amount of the light receiver 421b is detected, it is possible to detect whether or not the glass preform G exists on the lower mold 420.

Moreover, since a semiconductor laser light source, a semiconductor photoelectric element, etc. are used for the light transmitter 421a and the light receiver 421b, it is preferable to arrange | position it as far from the press apparatus 41 as possible. In this way, compared with the case where the semiconductor laser or the semiconductor photoelectric element is placed near the mold, temperature control is easier and the influence (noise) of the high frequency heating current is reduced.

Here, as shown in FIG. 5, the control means 50 inputs the measurement signal from a sensor (pressure sensor 224, optical sensor 421 (light receiver 421b), and glass preform G And the press unit (initial press load (torque), initial press completed position, second press load, third press load, etc.) corresponding to the number of preforms (G) The press condition at the time of shaping | molding is determined based on the memory | storage part 502 previously calculated | required, the data (table), and the data stored in the memory | storage part 502, the signal from the determination part 501, and the data | stored. A setting unit 503 and a servo controller 504 for outputting a signal corresponding to the output from the setting unit 503 to the servomotor (drive unit) 51.

The servomotor 51 also has an encoder 51a for detecting whether the lower mold 420 has moved by a predetermined press stroke.

In addition, as shown in FIG. 1, a high frequency induction heating coil 410 is installed around the molding mold to heat it. Prior to pressing the glass preform G, the molding mold is heated by the induction heating coil 410 and maintained at a predetermined temperature. The temperature of the molding mold at the time of press may be substantially the same as the temperature of the preheated glass preform G, and may be lower than it.

The carrying out device 42 transfers the glass optical element pressed by the press apparatus 41 to the extraction preparation chamber 43. The discharging device 42 is provided with six suction pads 42c at the tip of the arm 42b which is rotatably supported with respect to the drive part 42a. The suction pad 42c vacuum-suctions six glass optical elements on the lower mold of the molding mold, and enables the conveyance by the carrying device 42 to be carried out. The glass optical element adsorbed by the rotation of the arm 42b is conveyed below the extraction preparation chamber 43 and placed on the lifting means (not shown) provided therein. After retraction of the arm 42b, the lifting means is raised, and the glass optical element is transferred to the extraction preparation chamber 43. The discharging device 42 can also be provided with a pressure sensor type detection device provided in the preform supply device 22. In this way, the adsorption error of the glass optical element from the lower mold 420 can be detected.

In this embodiment, the opening of the extraction preparation chamber 43 which communicates with the shaping | molding chamber 40 is closed by the lens mounting surface of the lifting means, and the extraction preparation chamber 43 and the shaping | molding chamber 40 are thereby closed. The gas exchange between them becomes impossible. By opening the upper part of the extraction preparation chamber 43, the glass optical element inside it is carried out to the outside one by one using the robot arm or other carrying means. After the glass optical element is taken out, the extraction preparation chamber 43 is sealed and inert gas is filled therein.

In the above embodiment, the number of the preforms is detected in accordance with the pressure change of the suction path 223 of the preform supply device 22, and the number of the preforms placed on the lower mold 420 is measured by the optical sensor 421. Although an example of detecting with reference to) has been described, there is no problem even in the case of using only one detection means.

 The optical element manufacturing apparatus of this embodiment which consists of the said structure operates as follows.

The glass preform G of the preform conveyance device 23 at the glass preform supply position at the glass preform supply position while being adsorbed by the six adsorption pads 221 of the preform supply device 22 above the heating chamber 20. It is carried on the arm 25. Thereafter, the suction is stopped to drop the preform G onto the tray 26 of the arm 25, and then the suction pad 221 is raised. The arm 25 is then rotated to preheat the glass preform G with the preform heating device 24. The glass preform G is floated by the gas ejected from the lower part of the floating tray 26 through the inside of the arm 25, and when preheated to a desired temperature by the preform heating device 24, the arm ( 25 is further rotated to stop in the passage 60. Thereafter, the gate 61 is opened, and the arm 25 moves forward and moves up to the lower mold 420 of the press apparatus 41, where the arm 25 is opened to lower the mold from the floating tray 26. The glass preform (G) is dropped and supplied above (420). Thereafter, the arm 25 is retracted and rotated to return to the supply position of the glass preform G.

In the molding chamber 40, after the glass preform G is supplied to the lower mold 420, the lower mold 420 is raised to start the press by the upper and lower molding molds. When the press is finished and the mold separation and lower mold descending start, the discharging device 42 of the glass optical element is rotated from the standby position (preheating position) to move over the lower mold 420, and the suction pad 42c The molded article is adsorbed and extracted by

By repeating the above steps, continuous press molding is performed.

During the press molding process, the number of glass preforms G is detected when the glass preforms G are supplied from the preform supply device 22 to the conveying device 23. At this time, the pressure inside each suction path 223 of the preform supply device 22 is measured by the pressure sensor 224, and the measurement data is sent to the controller 50.

In addition, when the glass preform G supplied to the lower mold 420 is measured by the optical sensor 421 to detect the number of glass preforms G, the glass 25 is transferred from the arm 25 to the lower mold 420. The preliminary molded object G is projected by measuring the timing at which the preform G is supplied, and the measurement data from the light receiver 421b is input to the controller 50 (see FIGS. 3 and 4).

The control part 50 selects initial press load-3rd press load (and initial press completed position) from the table | storage stored in the memory | storage part 502 based on the input measurement data (number), and outputs it as output data. (See Fig. 5). The drive signal is output from the servo controller 504 to the servo motor 51 on the basis of the set data, the drive shaft (not shown) of the lower mold 420 is raised to perform initial press by the set press load. And when it reaches predetermined thickness, an initial press is completed.

Here, the determination of whether or not the predetermined thickness is achieved is determined by the movement stroke of the lower mold 420 predetermined. In other words, the press stroke corresponding to the predetermined thickness is obtained in advance, and this is detected by the encoder 51a of the servomotor 51, and it is determined that the predetermined thickness has been reached (see Fig. 5).

In addition, when a load is applied at the time of pressing, some elastic deformation may occur in the structure of the press apparatus 41, for example, the holding member of the molding mold or the press shaft. And this amount of deformation changes when the load is changed. Therefore, when the load is changed in accordance with the number of preforms G, the thickness of the glass optical element may vary. Therefore, it is necessary to correct the amount of change due to elastic deformation according to the amount of press stroke. Therefore, when such a phenomenon may occur, the stroke considering the correction amount is obtained in advance as the initial press end position for each value of the load to be selected, and after the initial press is finished, the drive shaft is moved to the initial press end position.

Here, the predetermined thickness is taken into account the shrinkage of the product by the cooling of the post-process, and refers to a thickness of about 0 to 200 µm, preferably 10 to 100 µm larger than the thickness of the final product.

Next, the load is reduced to apply a second press load. At this time, cooling is also performed simultaneously. Moreover, when cooling to predetermined temperature is performed, it presses by a 3rd press load. It is preferable to make a 3rd press load smaller than the load at the time of an initial press, and to make it larger than the load at the time of a 2nd press. The third press is carried out while cooling to obtain the thickness of the final product.

It is preferable to select and set the press loads in the second and third presses according to the number of the preforms G, too.

In the present embodiment, the upper mold is fixed and the lower mold is movable. However, the upper mold may be movable and the lower mold may be fixed. Alternatively, both the upper mold and the lower mold may be moved. In addition, the suction path 222 of the suction pad 221 in the preform supply device 22 may be sucked by one suction path without being formed independently for each suction pad 221. In this case, the number of preforms G is detected by measuring the pressure in the one suction path.

Furthermore, in addition to providing one optical sensor for each lower mold, a line sensor can also be used. In this case, the number of glass preforms G is determined according to the light receiving amount of the light receiver.

In addition, in this embodiment, although the example which press-molds by selecting suitable press load data was shown from the table | storage stored in the memory | storage part 502 based on the number of glass preforms G detected, the press molding was shown, Not only the load data but also data on the press amount, the press time, and the press speed may be selected, and press molding may be performed according to the data.

The optical element manufactured by the method of this invention can be made into a lens, for example, and there is no restriction | limiting in particular in shape, It can be set as both convex, concave meniscus, convex meniscus, etc. In particular, even a medium-diameter lens having a lens outer diameter of about 15 to 25 mm, thickness, eccentricity, and the like can be maintained well. For example, the thickness precision is within ± 0.03 mm. In terms of eccentricity, the tilt (inclination of the mutual axis of the upper mold and the lower mold) is within 2 minutes, and the shift (shift in the horizontal direction of the mutual axis of the upper mold and the lower mold) is 10 minutes. In manufacturing the thing within a micrometer, this invention can be applied suitably.

Next, the Example and comparative example which produced the glass optical element using the shaping | molding apparatus of this invention and a manufacturing method are shown.

EXAMPLE

The example which press-molded the concave meniscus lens is shown using the optical glass manufacturing apparatus 10 (press molding apparatus) shown in FIG. In the press-molding apparatus, the method shown in Fig. 2 is employed in which the preform supply device 22 detects the suction pressure when the glass preform G is supplied to the arm 25.

As the glass preform (G), a flat spherical preform of barium borosilicate glass M-BaCD5N (Tg 515 ° C) was used. Six glass preforms (G) were placed in a supply tray in the supply preparation chamber (21) so that the preform supply device (22) adsorbs the six glass preforms (G). The glass preform G is supplied from the preform supply device 22 to the arm 25 of the preform conveying device 23 and maintained in the floating state by the arm 25, while being supplied to the heating device 24. Preheated to 610 ° C. and also preheated to a lower mold 420 preheated to 580 ° C.

Subsequently, the lower mold 420 was raised to perform an initial press under a predetermined load. This initial press is performed until the center thickness is about 70 micrometers thicker than a desired value. After the initial press was completed, the second press was performed under a predetermined load. At this time, when the cooling was started and the temperature reached 555 ° C, the third press was further performed under a predetermined load. Thereafter, the mold was separated when the lower mold was lower than the Tg. At the time of the initial press-the 3rd press, and the initial press completed position, the value with respect to six glass preforms G was selected and set.

Next, four glass preforms G were placed in the supply tray of the supply preparation chamber 21 so that there were four glass preforms G adsorbed by the preform supply device 22. After continuous pressing, the pressure sensor 224 detects that the number of glass preforms G is four, and the loads and initial press completion positions corresponding to the four initial presses to the third presses are selected and set. Press molding was performed based on this data. The center thicknesses of the four lenses thus formed are 1.195 mmt, 1.192 mmt, 1.193 mmt, and 1.189 mmt, and the surface precision of any lens is 0.5 [irregularity (rotationally symmetric curvature deviation occurring in the lens)] [0.5 fringe ], Good quality was obtained similarly to the case where 6 were pressed simultaneously. Here, "bending" refers to the distortion of the interference fringe, and is used for evaluation of the lens.

According to the number of presses at a time, the results of obtaining the loads of the initial presses and the third presses and the initial press completion positions in advance so that the center thickness is about 1.20 mm are shown in Table 1 (in addition, the sliding resistance component is included in the loads). ).

Glass preforms (pcs) First (initial) press load (kg) Initial press end position (mm) 2nd press load (kg) 3rd press load (kg) One 300 240.520 240 280 2 400 240.536 260 340 3 500 240.552 280 400 4 600 240.568 300 460 5 700 240.584 320 520 6 800 240.600 340 580

[Comparative Example]

The number detection and control system of the glass preform G was not operated and only the conditions of the six glass preforms of Table 1 were set. In this state, four glass preforms (G) were supplied and molded. Other than that, it shape | molded similarly to an Example. The lenses supplied in four cycles were 1.165mmt, 1.161mmt, 1.162mmt, and 1.157mmt, and the center thickness was less than the specification value of 1.200mm ± 0.03mm, and the surface precision became 3-4 pieces, resulting in defective products. .

According to the present invention, in the case of press molding a plurality of glass preforms at once, an optical element having a desired thickness and surface precision even when the number of glass preforms disposed in the mold is changed due to a supply error or the like of the glass preforms. It is possible to obtain a molding apparatus for an optical element and a method of manufacturing the same.

Claims (10)

A manufacturing apparatus for simultaneously press-molding a plurality of molding materials by a molding mold, Molding material detecting means for detecting the number of the molding materials to be press-molded; Drive means for driving the molding mold and press molding; And a driving control means for selecting a press condition on the basis of the number of molded materials detected and driving the drive means in accordance with the selected press condition. The method of claim 1, And said press condition is at least one condition selected from the group consisting of press load, press time, press amount and press speed. A manufacturing apparatus for simultaneously press-molding a plurality of molding materials by a molding mold, Molding material detecting means for detecting the number of the molding materials to be press-molded; Drive means for driving the molding mold and press molding; And a drive control means for selecting a press load based on the number of the molded materials detected, and for driving the drive means in accordance with the selected press load. The method of claim 3, wherein And the drive control means selects a press stop position based on the number of the detected molding materials or the selected press load, and drives the drive means in accordance with the selected press stop position. The method according to claim 1 or 3, When the molded material is sucked and held by the suction supply means, a pressure detection means is provided in the suction path of the suction supply means, and the pressure detection means detects the number of the supplied molding materials. Apparatus for manufacturing optical element. The method of claim 5, The suction path of the suction supply means is formed for each of the plurality of molded materials, and the pressure detecting means is provided for each of the plurality of suction paths. The method according to claim 1 or 3, An optical detecting means for optically detecting the molded material at a supply position of the plurality of molded materials, and the optical detecting means detects the number of supplied molded materials. . An optical element is manufactured by press molding a molding material in a softened state by heating using the manufacturing apparatus according to claim 1. An optical element is manufactured by press molding a molding material in a softened state by heating using the manufacturing apparatus according to claim 3. The method of claim 9, The press molding step is a case of having an initial press and a second press which presses with a smaller load than the initial press, And the initial press is performed by driving the driving means in accordance with the selected press load.

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