JP2012232383A - Apparatus and method for manufacturing optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing an optical element which can measure a thickness of an optical element material as needed without taking a time and effort, and to provide a method for manufacturing the optical element.SOLUTION: The apparatus for manufacturing an optical element includes: an optical element retainer 11 for retaining the optical element material 10; a processing tool supporting device 21 for supporting a processing tool 20 that abuts on a processing surface 10a of the optical element material 10 and grinds or polishes the optical element material 10; a motor and a movement controller for moving the optical element material 10 and the processing tool 20 relatively to each other; and a measurement unit 30 provided at a side opposite to the side of the processing tool 20 supported by the processing tool supporting device 21 relative to the optical element material 10 retained by the optical element retainer 11 and measuring a thickness of the optical element material 10 in a noncontact manner.

Description

  The present invention relates to an optical element manufacturing apparatus and an optical element manufacturing method for grinding and polishing optical elements such as lenses.

  Conventionally, spherical surface creation processing for an optical element such as a lens is performed by bringing a cup-shaped processing tool into contact with the processing surface of the optical element held by a holder, rotating the optical element, and rotating the processing tool. This is done by grinding the processed surface of the optical element.

  In order to manufacture an optical element with high accuracy, it is necessary to set accurate processing conditions. Therefore, for example, Patent Document 1 discloses that a machining condition is corrected based on measured values such as a diameter and a thickness of an optical element material that has been initially machined in an NC apparatus for spherical surface creation machining or the like. For example, Patent Document 2 discloses an apparatus for measuring the thickness of a test lens in a non-contact manner on a lens processing machine.

JP-A-10-156690 JP 2002-310620 A

  By the way, the measurement of the thickness of the optical element material by the non-contact method is performed by irradiating the processing surface of the optical element material with measurement light. For this reason, usually, the optical element material must be temporarily removed from the optical element manufacturing apparatus, and measurement must be performed in an external measuring apparatus. Even when the measuring device is provided inside the optical element manufacturing apparatus, it is necessary to perform the measurement after temporarily retracting the optical element material from the processing tool to a position that does not interfere with the measurement. For this reason, when measurement is performed during processing of the optical element material, a lot of labor and time are required.

  The present invention has been made in view of the above, and an object of the present invention is to provide an optical element manufacturing apparatus and an optical element manufacturing method capable of measuring the thickness of an optical element material as needed without taking time and effort. And

  In order to solve the above-described problems and achieve the object, an optical element manufacturing apparatus according to the present invention abuts on a holding means for holding an optical element material and a processing surface of the optical element material, A motion tool supporting means for supporting a processing tool to be ground or polished, and a motion for providing a relative motion between the optical element material held by the holding means and the processing tool supported by the processing tool support means A mechanism and the optical element material held by the holding means are provided on the opposite side of the processing tool supported by the processing tool support means, and the thickness of the optical element material is measured in a non-contact manner. And measuring means.

  In the optical element manufacturing apparatus, the measurement unit includes a light source provided on the side opposite to the processing tool supported by the processing tool support unit with respect to the optical element material held by the holding unit, Based on the optical system that makes the light emitted from the light source incident on the surface opposite to the processed surface of the optical element material held by the holding means, and the light reflected by the optical element material, And a measurement processing means for measuring the thickness of the optical element material.

  In the optical element manufacturing apparatus, the light source is a light source that emits low-coherence light, and the optical system emits light emitted from the light source parallel to the optical axis of the optical element material held by the holding unit. A light splitting unit that splits the measurement light into reference light having an optical path orthogonal to the measurement light and makes the measurement light incident on a surface opposite to the processed surface of the optical element material; A reference mirror having a reflecting surface orthogonal to the optical path and movable along the optical path of the reference light, and the measurement processing means is configured to use the measurement light reflected by the optical element material and the reference mirror. Based on the reflected reference light, the thickness of the optical element material is measured by the principle of spectral interferometry.

  In the optical element manufacturing apparatus, the holding means is a holder that holds the optical element material, and passes light emitted from the light source toward a surface opposite to the processing surface of the optical element material. It is provided with the holder provided with the penetration path to be made.

  The optical element manufacturing apparatus further includes notification means for notifying the thickness measured by the measurement means.

  The optical element manufacturing apparatus further includes a control unit that stops the operation and causes the measurement unit to measure the thickness when a predetermined time has elapsed from the start of the operation of grinding or polishing the processed surface. It is characterized by.

  The optical element manufacturing apparatus includes a control unit that stops the operation and measures the thickness by the measurement unit when a predetermined time has elapsed from the start of the operation of grinding or polishing the processed surface, and the thickness Determining means for determining whether or not is less than or equal to a predetermined set value, and when the thickness is less than or equal to the set value, the control means performs the processing of the processing tool and the optical element material Control is performed to move at least one of the processing tool and the optical element material so as to be separated from the surface.

  The optical element manufacturing apparatus includes: a determination unit that determines whether the thickness measured by the measurement unit is equal to or less than a predetermined set value; and the processing when the thickness is equal to or less than the set value. Control for stopping the operation of grinding or polishing the surface, and controlling to move at least one of the processing tool and the optical element material so that the processing tool and the processing surface of the optical element material are separated from each other And a means.

  The optical element manufacturing apparatus further includes notification means for notifying information relating to manufacturing of the optical element, and the control means finishes processing with respect to the notification means when the thickness is equal to or less than the set value. It is characterized by notifying.

  In the optical element manufacturing apparatus, the notification unit performs notification by at least one of screen display, lighting or blinking, sound output, and notification sound output.

An optical element manufacturing method according to the present invention includes a holding step of holding an optical element material in a holding means,
A processing step of grinding or polishing the processing surface by rotating at least one of the holding unit and the processing tool, and a measuring unit provided on the side opposite to the processing tool with respect to the optical element material And a measuring step of measuring the thickness of the optical element material in a non-contact manner in a state where the processing tool is in contact with the processing surface.

  According to the present invention, since the thickness of the optical element material is measured in a non-contact manner by the measuring means provided on the side opposite to the processing tool with respect to the optical element material, it is troublesome to retract the optical element material from the processing tool. In addition, the thickness of the optical element material can be measured at any time without taking time.

FIG. 1 is a top view showing an optical element manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 2 is a side view of the optical element manufacturing apparatus shown in FIG. FIG. 3 is a partial cross-sectional view taken along line BB in FIG. FIG. 4 is a block diagram showing a configuration of the optical element manufacturing apparatus shown in FIG. FIG. 5 is a flowchart showing the optical element manufacturing method according to Embodiment 1 of the present invention. FIG. 6A is a schematic diagram showing the operation of the optical element shown in FIG. FIG. 6B is a schematic diagram showing the operation of the optical element shown in FIG. FIG. 6C is a schematic diagram showing the operation of the optical element shown in FIG. FIG. 6D is a schematic diagram illustrating an operation of the optical element illustrated in FIG. 1. FIG. 6E is a schematic diagram showing the operation of the optical element shown in FIG. FIG. 7 is a block diagram showing the configuration of the optical element manufacturing apparatus according to Embodiment 2 of the present invention. FIG. 8 is a flowchart showing an optical element manufacturing method according to Embodiment 2 of the present invention. FIG. 9 is a flowchart showing an optical element manufacturing method according to Embodiment 3 of the present invention. FIG. 10 is a partial cross-sectional view showing an optical element manufacturing apparatus according to Embodiment 4 of the present invention.

Hereinafter, an optical element supporting device and an optical element manufacturing method according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each part are different from the actual ones. Also in the drawings, there are included portions having different dimensional relationships and ratios.
In the present application, the spherical surface refers to a curved surface that is a part of the surface of the sphere in addition to the surface of the sphere.

(Embodiment 1)
FIG. 1 is a top view showing the configuration of the optical element manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 2 is a side view of the optical element manufacturing apparatus 1 shown in FIG. FIG. 3 is a partial cross-sectional view taken along line BB in FIG. FIG. 4 is a block diagram showing a configuration of the optical element manufacturing apparatus 1.

  As shown in FIGS. 1 to 3, the optical element manufacturing apparatus 1 grinds an optical element holder 11 that holds an optical element material 10 that is a workpiece, and a processing surface 10 a of the optical element material 10. The processing tool 20 to be applied, the processing tool support device 21 that supports the processing tool 20, and the optical element material 10 are provided on the opposite side of the processing tool 20, and the thickness of the optical element material 10 is measured in a non-contact manner. The measuring unit 30, the display unit 40, and a processing control unit 50 that controls a processing operation on the optical element material 10 are provided.

  The optical element holder 11 includes a cylindrical holding part 11a provided with a concave part 11b into which the optical element material 10 is fitted, and a cylindrical support part 11c having a smaller diameter than the holding part 11a. The holding part 11a and the support part 11c are integrally formed. The recess 11b is formed such that the optical axis of the optical element material 10 coincides with the axis R1 of the optical element holder 11 when the optical element material 10 is fitted.

  The optical element holder 11 is provided with a spindle 12, a motor 13, and a belt 14 as a rotation mechanism that imparts a rotational motion to the optical element holder 11. The spindle 12 rotatably supports the outer periphery of the support portion 11c. Further, the belt 14 transmits the rotational motion of the motor 13 to the support portion 11c. By such a rotation mechanism, the optical element holder 11 and the optical element material 10 held therein rotate about the axis R1 as a rotation axis. The optical element material 10, the optical element holder 11, the spindle 12, the motor 13, and the belt 14 are integrated and freely movable along the axis R1 by the support mechanism 15 that operates under the control of the processing control unit 50. It is supported by.

As shown in FIG. 3, a through-passage 11e penetrating from the concave portion 11b to the bottom portion 11d of the support portion 11c is provided in the rotation center portion including the axis R1 of the optical element holder 11. The through passage 11 e is a passage through which the measurement light Lb ₁ emitted from the measurement unit 30 passes along the axis R ₁ and enters the holding surface 10 b of the optical element material 10.

  The processing tool 20 is a cup-shaped processing tool for creating a spherical surface having a cylindrical outer shape and having a recess 20a at one bottom of the columnar shape. The edge of the recess 20a is brought into contact with the processing surface 10a of the optical element material 10 and acts as a grindstone for grinding the processing surface 10a into a spherical shape.

  The processing tool support device 21 supports the processing tool 20 so that the processing tool 20 is rotatable about the axis R2 and the axis R2 is freely angled with respect to the axis R1, and is translated in a direction parallel to a plane orthogonal to the axis R1. Support freely. Further, the processing tool support device 21 supports the processing tool 20 so that the axis R2 intersects the axis R1 at the spherical spherical center that is the final shape obtained by processing the processing surface 10a. Such a processing tool support device 21 operates under the control of a position control unit 54 and a motion control unit 55 described later, and moves the processing tool 20 and gives a rotational motion to the processing tool 20.

  The measuring unit 30 is provided on the axis R1 and the light source 31 is provided on the axis R1, and the light incident from the direction of the light source 31 is divided to divide the direction of the axis R1 and the direction of the axis R3 orthogonal to the axis R1. A prism 32 serving as a dividing unit (in the downward direction in the figure), a reference mirror 33 provided on the axis R3, a mirror support device 34 for supporting the reference mirror 33, and on the axis R3, the prism 32. On the other hand, the thickness of the optical element material 10 is measured based on the image sensor 35 provided on the opposite side of the reference mirror 33 and the electric signal output from the image sensor 35, and the operation of each part of the measurement unit 30 is performed. And a measurement processing unit 36 to be controlled.

  The light source 31 is a light source that emits low-coherence light (light beam) La, and is installed on the bottom 11d side of the optical element holder 11 so that the optical axis of the low-coherence light La coincides with the axis R1. As the light source 31, a light source having a short coherence length, for example, ASE (Amplified Spontaneous Emission), LED (Light Emitting Diode), SLD (Super Luminescent Diode), or the like is used.

  The prism 32 transmits part of the light incident from the direction of the light source 31 in the direction of the optical element material 10 and reflects the remaining light in the direction of the reference mirror 33. The prism 32 reflects light incident from the direction of the optical element material 10 in the direction of the axis R3 (upper side in the figure) and transmits light incident from the direction of the reference mirror 33. In addition to the prism 32, an optical element such as a beam splitter (half mirror) may be used as the light splitting unit that splits the light emitted from the light source 31.

The reference mirror 33 is a reflection mirror having a reflection surface orthogonal to the axis R3.
The mirror support device 34 supports the reference mirror 33 so as to be movable along the axis R <b> 3 under the control of the measurement processing unit 36. Thereby, the distance between the reference mirror 33 and the prism 32 is adjusted.

  The imaging element 35 is realized by a photoelectric conversion element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The image sensor 35 has a light receiving surface on which light coming from the direction of the prism 32 is incident, and photoelectrically converts the light incident on the light receiving surface to output an electrical signal.

  The measurement processing unit 36 calculates the thickness of the optical element material 10 based on the principle of spectral interferometry based on the electrical signal output from the image sensor 35.

  The display unit 40 is a notification unit that notifies the user by displaying the thickness of the optical element material 10 calculated by the measurement processing unit 36 and various information and commands input from the processing control unit 50 on the screen. . Specifically, the display unit 40 is realized by a display device such as an LCD or an EL display. In addition to the screen display function, the display unit 40 may have a function of notifying the user of predetermined information by turning on or blinking LED lighting, outputting sound, outputting notification sound, or the like.

  The processing control unit 50 includes an input unit 51 that receives input of various commands and information to the optical element manufacturing apparatus 1, a control unit 52 that controls the operation of the entire optical element manufacturing apparatus 1, and a motor that controls driving of the motor 13. A control unit 53, a position control unit 54 that controls the relative positional relationship between the optical element material 10 and the processing tool 20, and a motion control unit 55 that controls the motion of the processing tool support device 21 are provided. Among these, the input unit 51 is realized by an operation button, a keyboard, a pointing device such as a mouse and a touch panel, and the like.

  The position control unit 54 controls the operation of the support mechanism 15 so that the optical element material 10, the optical element holder 11, the spindle 12, the motor 13, and the belt 14 are moved together along the axis R1. Further, the motion control unit 55 controls the operation of the processing tool support device 21 so that the processing tool 20 performs a rotational motion about the axis R2.

  Note that the rotation mechanism (spindle 12, motor 13, belt 14) and / or motion control unit 55 provided in the optical element holder 11 may be provided relative to each other between the optical element material 10 and the processing tool 20. It corresponds to a movement mechanism that gives a simple movement.

Next, the principle of measuring the thickness of the optical element material 10 in the measurement unit 30 will be described.
A light beam La of low-coherence light emitted from the light source 31 is split by the prism 32 into measurement light Lb ₁ that is transmitted in the direction of the axis R ₁ and reference light Lc that is reflected in the direction of the axis R 3. The measurement light Lb ₁ passes through the through-passage 11 e and enters the holding surface 10 b of the optical element material 10. At this time, a part of the measurement light Lb ₁ is reflected by the holding surface 10b and returns in the direction of the prism 32 (measurement light Lb ₁ ′), and the remainder of the measurement light Lb ₁ proceeds directly into the optical element material 10 (measurement). Light Lb ₂ ). The measurement light Lb ₂ is reflected on the processed surface 10a and returns in the direction of the prism 32 (measurement light Lb ₂ ′).
On the other hand, the reference light Lc is reflected by the reference mirror 33 and returns in the direction of the prism 32 (reference light Lc ′).

The prism 32 reflects the measurement lights Lb ₁ ′ and Lb ₂ ′ in the direction of the image sensor 35 and transmits the reference light Lc ′. Thereby, the combined light Ld of the measurement light Lb ₁ ′, Lb ₂ ′ and the reference light Lc ′ is incident on the light receiving surface of the image sensor 35.

On the light receiving surface of the image sensor 35, interference fringes are observed due to interference between the measurement light Lb ₁ ′ or the measurement light Lb ₂ ′ and the reference light Lc ′. This interference fringe changes according to the position of the reference mirror 33. Therefore, the measurement processing unit 36 measures the change in the interference intensity in the interference fringes while moving the reference mirror 33 at a predetermined speed, the peak corresponding to the interference between the measurement light Lb ₁ ′ and the reference light Lc ′, and A peak corresponding to interference between the measurement light Lb ₂ ′ and the reference light Lc ′ is detected. Further, the measurement processing unit 36 calculates the optical path length difference between the measurement light Lb ₁ ′ and the measurement light Lb ₂ ′ based on the position of the reference mirror 33 at these peaks, and the optical path length difference and the optical element material 10 are calculated. From the refractive index, the thickness of the optical element material 10 is calculated.

  Next, the optical element manufacturing method according to Embodiment 1 will be described with reference to FIGS. 5 and 6A to 6E. FIG. 5 is a flowchart showing the optical element manufacturing method according to the first embodiment. 6A to 6E are schematic diagrams illustrating the operation of the optical element manufacturing apparatus 1. FIG. In addition, description of the process control part 50 is abbreviate | omitted in FIG. 6A-FIG. 6E. In the following description, it is assumed that the processing tool 20 is attached to the processing tool support device 21 in advance.

  First, in step S01, the optical element material 10 is attached to the recess 11b of the optical element holder 11 as shown in FIG. 6A. The optical element material 10 may be attached manually by a user, or may be automatically provided by separately providing a transport device and an attachment device.

  In the subsequent step S02, the control unit 52 sets a processing time for the optical element material 10 in accordance with the input signal received by the input unit 51. Here, the thickness of the optical element material 10 is cut to any position at the end of machining in the machining process in which the optical element material 10 is translated (cut) in the direction of approaching the machining tool 20 along the axis R1. It is decided by what. Therefore, by measuring in advance the relationship (actual measurement data) between the cut amount and the thickness of the optical element material 10, the cut amount corresponding to the desired thickness can be calculated. Further, under the condition that the cutting speed is constant, the machining time can be calculated from the desired cutting amount. In step S02, a processing time corresponding to a desired thickness is set based on such actual measurement data. Alternatively, a process for automatically setting the processing time may be incorporated based on the actual measurement data by inputting a desired thickness.

  In step S03, the control unit 52 starts a processing operation on the optical element material 10 for each unit. In response to this, the motor 13 gives a rotational motion to the optical element holder 11, and the processing tool support device 21 gives a rotational motion to the processing tool 20. Furthermore, the support mechanism 15 integrally translates the optical element material 10, the optical element holder 11, the spindle 12, the motor 13, and the belt 14 at a constant speed in the direction of approaching the processing tool 20 along the axis R1 ( (See FIG. 6B). Thereby, the grinding process with respect to the process surface 10a is performed (process S04).

  In step S05, the control unit 52 determines whether or not the machining time (set time) set in step S02 has elapsed. When the set time has elapsed (step S05: Yes), the control unit 52 stops the machining operation on the machining surface 10a (step S06). On the other hand, when setting time has not passed (process S05: No), the control part 52 continues the process with respect to the processed surface 10a (process S04).

In step S07, the measurement unit 30 to emit a light beam La (see FIG. 3) from the light source 31, by irradiating the measurement light Lb ₁ on the holding surface 10b of the optical element material 10, the thickness of the optical element material 10 Measure (see FIG. 6C).

  In step S08, the display unit 40 displays the measured value of the thickness of the optical element material 10 measured by the measurement unit 30. At this time, the display unit 40 may notify the measurement value by voice.

  In step S09, the user looks at the measurement value displayed on the display unit 40, determines whether or not the measurement value has reached a desired value (target value), and inputs the determination result to the input unit 51.

  When the determination result that the measured value is larger than the target value is input (step S09: No), the control unit 52 sets the machining time again (step S10). The processing time set at this time may be manually input by the user, or the control unit 52 performs processing based on the measured value of the thickness of the optical element material 10 and the set value set in step S02. It is also possible to change the time. Thereafter, the process proceeds to step S03.

  On the other hand, when the determination result that the measured value is equal to or less than the target value is input (step S09: Yes), the support mechanism 15 is configured so that the processing tool 20 and the processing surface 10a of the optical element material 10 are separated from each other. The optical element material 10, the optical element holder 11, the spindle 12, the motor 13, and the belt 14 are moved and retracted from the processing tool 20 (step S11, see FIG. 6D).

  Further, in step S12, the optical element material 10 is removed from the optical element holder 11 as shown in FIG. 6E. Thereby, the optical element material 10 processed into a desired thickness can be obtained. In addition, when providing the conveying apparatus and attachment apparatus of the optical element material 10 separately, removal of the processed optical element material 10 and attachment to the optical element holder 11 of another optical element material 10 (process S01) are carried out. It may be performed automatically and the processes of steps S02 to S12 may be repeated.

  As described above, according to the first embodiment, while the optical element material 10 is processed, the thickness of the optical element material 10 is measured with the processing tool 20 in contact with the processing surface 10a. be able to. That is, the thickness of the optical element material is measured without taking time and effort such as removing the optical element material from the optical element manufacturing apparatus and moving it to another measuring apparatus or temporarily retracting the optical element material from the processing tool. It becomes possible. According to the first embodiment, as described above, the thickness of the optical element material 10 can be measured at any time, so that an optical element with high thickness accuracy can be manufactured.

  Moreover, according to Embodiment 1, when the processing of the optical element material 10 is completed, the thickness of the optical element material 10 can be measured in that state. Therefore, according to the first embodiment, it is possible to perform 100% inspection even when only the thickness extraction inspection for a part of the optical element material can be performed conventionally due to time and labor constraints. Become.

  Further, according to the first embodiment, since the processing operation for the optical element material is controlled based on the measured value of the thickness of the optical element material, the structure and state of the optical element manufacturing apparatus (for example, the holding condition of the optical element material). Even if the processing tool wears, the temperature change, and the like vary from device to device, it is possible to manufacture an optical element having no variation in thickness.

  Furthermore, according to the first embodiment, since the user can grasp the thickness of the optical element material 10 at any time, even if not a skilled worker, accurate processing conditions (processing time, optical element) can be obtained in a short time. It is possible to set the rotation speed of the material.

(Modification 1)
In the first embodiment, the thickness of the optical element material 10 is measured after the processing operation is temporarily stopped. However, the thickness of the optical element material 10 may be measured in parallel with the processing operation. In this case, the measuring unit 30 sequentially outputs and displays the measured thickness on the display unit 40. The user can stop the machining operation by operating the input unit 51 when the thickness reaches a desired value by looking at the thickness displayed on the display unit 40.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
FIG. 7 is a block diagram showing a configuration of the optical element manufacturing apparatus according to the second embodiment. As shown in FIG. 7, the optical element manufacturing apparatus 2 according to Embodiment 2 includes a processing control unit 60 having a determination unit 61 and a control unit 62 instead of the processing control unit 50 shown in FIG. 3.

  The determination unit 61 determines whether the thickness of the optical element material 10 measured by the measurement unit 30 is equal to or less than a predetermined set value. The control unit 62 controls the operation of each unit of the optical element manufacturing apparatus 2 based on the determination result of the determination unit 61. Other configurations are the same as those in the first embodiment.

FIG. 8 is a flowchart showing an optical element manufacturing method according to the second embodiment.
First, in step S21, the optical element material 10 is attached to the recess 11b of the optical element holder 11 (see FIG. 6A). The optical element material 10 may be attached manually by the user, or may be automatically provided by separately providing a transport device and an attachment device.

  In step S22, the control unit 62 sets the thickness (set value) of the optical element material 10 after grinding according to the input signal received by the input unit 51. Note that the set value may be a target value for the thickness at the time of finishing, or may be a value slightly larger than the target value in consideration of the time required for stop control of the machining operation. In the latter case, the control unit 52 may automatically add a predetermined value to the target value input by the user.

  In step S <b> 23, the control unit 62 starts a processing operation on the optical element material 10 for each unit. In response to this, the motor 13 gives a rotational motion to the optical element holder 11, and the processing tool support device 21 gives a rotational motion to the processing tool 20. Further, the support mechanism 15 integrally translates the optical element material 10, the optical element holder 11, the spindle 12, the motor 13, and the belt 14 at a constant speed in the direction of approaching the processing tool 20 along the axis R1 ( (See FIG. 6B). Thereby, the grinding process with respect to the process surface 10a is performed (process S24).

  In step S25, the control unit 62 determines whether or not a predetermined time has elapsed since the machining operation was started. This time is preset based on the cutting speed so that the optical element material 10 is ground by a predetermined thickness.

  When the predetermined time has elapsed (step S25: Yes), the control unit 62 stops the machining operation on the machining surface 10a for each part (step S26). On the other hand, when the predetermined time has not elapsed (step S25: No), the control unit 62 continues the processing on the processing surface 10a (step S24).

In step S27, the measurement unit 30 to emit a light beam La (see FIG. 3) from the light source 31, by irradiating the measurement light Lb ₁ on the holding surface 10b of the optical element material 10, the thickness of the optical element material 10 Measure (see FIG. 6C). At this time, the control unit 62 may display the measured thickness value on the display unit 40.

  In step S28, the determination unit 61 determines whether or not the measured value of the thickness of the optical element material 10 is equal to or less than the set value set in step S22.

  When the measured value is larger than the set value (step S28: No), the process returns to step S23. In this case, the elapsed time (processing time) determined in step S25 may be set so that a constant cutting amount is always added, or the control unit 62 sets and sets the measured thickness value. The processing time may be changed based on the value.

  On the other hand, when the measured value is equal to or less than the set value (step S28: Yes), the support mechanism 15 holds the optical element material 10 and the optical element so that the processing tool 20 and the processing surface 10a of the optical element material 10 are separated from each other. The tool 11, the spindle 12, the motor 13, and the belt 14 are moved and retracted from the processing tool 20 (see step S29, FIG. 6D). In this case, the control unit 62 may display on the display unit 40 that the processing of the optical element material 10 has been completed. Or you may make it notify a user of completion | finish of a process by blinking of LED illumination, an audio | voice, a notification sound, etc. FIG.

  Further, in step S30, the optical element material 10 is removed from the optical element holder 11 (see FIG. 6E). Thereby, the optical element material 10 processed into a desired thickness can be obtained. In addition, when providing the conveying apparatus and attachment apparatus of the optical element material 10 separately, removal of the processed optical element material 10 and attachment to the optical element holder 11 of another optical element material 10 (process S21) are carried out. It may be performed automatically and the processes of steps S22 to S30 may be repeated. In this case, the step S22 may be omitted, and the setting value at the time of processing the first optical element material 10 may be repeatedly used in the determination of the step S28.

  As described above, according to the second embodiment, the thickness of the optical element material is periodically measured, and the processing operation for the optical element material is controlled based on the measurement result. The element can be automatically manufactured. In addition, even when a plurality of optical elements are sequentially manufactured, thickness measurement is performed on all the optical elements, so that it is possible to prevent rework due to a thickness defect.

  Furthermore, according to the second embodiment, since the processing operation is controlled based on the measured value of the thickness of the optical element material 10, the structure and state of the optical element manufacturing apparatus vary from apparatus to apparatus. Even if it exists, it becomes possible to manufacture the optical element without the dispersion | variation in thickness under the same processing conditions (processing time, the rotational speed of optical element material, etc.). Therefore, even an unskilled worker can easily set processing conditions and easily manufacture an optical element with good thickness accuracy.

(Embodiment 3)
Next, a third embodiment of the present invention will be described.
The optical element manufacturing method according to Embodiment 3 is characterized in that processing is performed while measuring the thickness of the optical element material in real time. The configuration of the optical element manufacturing apparatus according to Embodiment 3 is the same as that shown in FIG.

  FIG. 9 is a flowchart showing an optical element manufacturing method according to the third embodiment. The operations in steps S21 to S24, S29, and S30 are the same as those in the second embodiment.

In subsequent step S24 step S41, the measurement unit 30 to emit a light beam La (see FIG. 3) from the light source 31, by irradiating the measurement light Lb ₁ on the holding surface 10b of the optical element material 10, the optical element material 10 Is measured (see FIG. 6C). At this time, the control unit 62 may display the measured thickness value on the display unit 40.

  In step S42, the determination unit 61 determines whether the measured value of the thickness of the optical element material 10 is equal to or less than the set value set in step S22. And when a measured value is larger than a setting value (process S42: No), a process returns to process S24. On the other hand, when the measured value is less than or equal to the set value (step S42: Yes), the control unit 62 stops the machining operation on the machining surface 10a for each part (step S43). In this case, the control unit 62 may display on the display unit 40 that the processing of the optical element material 10 has been completed. Or you may make it notify a user of completion | finish of a process by blinking of LED illumination, an audio | voice, a notification sound, etc. FIG.

  As described above, according to the third embodiment, the thickness of the optical element material is measured in real time, and the processing operation for the optical element material is controlled based on the measurement result. Can be manufactured automatically. In addition, even when a plurality of optical elements are sequentially manufactured, thickness measurement is performed on all the optical elements, so that it is possible to prevent rework due to a thickness defect.

  In addition, according to the third embodiment, since the processing operation measured by the measured value of the thickness of the optical element material is controlled, the structure and state of the optical element manufacturing apparatus vary from apparatus to apparatus. Even if it exists, it becomes possible to manufacture the optical element without the dispersion | variation in thickness under the same process conditions. Therefore, even an unskilled worker can easily set processing conditions and easily manufacture an optical element with good thickness accuracy.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described.
FIG. 10 is a partial cross-sectional view showing the optical element manufacturing apparatus according to the fourth embodiment. As shown in FIG. 10, in the optical element manufacturing apparatus 4 according to the fourth embodiment, a processing tool 70 is attached to the processing tool support device 21. Other configurations of the optical element manufacturing apparatus 4 are the same as those in the first embodiment. Instead of the machining control unit 50, a machining control unit 60 may be provided as in the second and third embodiments.

  The processing tool 70 is a spherical processing tool in which a spherical concave portion 70a is provided at one bottom of a columnar shape. The concave spherical surface 70b is brought into contact with the processed surface 10a of the optical element material 10, and the processed surface 10a is ground or polished into a shape corresponding to the spherical surface 70b.

  When such a processing tool 70 is used, in the processing step for the optical element material 10 (see step S04 in FIG. 5), the motion control unit 55 moves the axis R2 with respect to the processing tool 70 via the processing tool support device 21. A rotational motion with a rotational axis and a swinging motion on a spherical surface with the intersection of the shaft R1 and the shaft R2 as a spherical center are given. Thereby, the processing surface 10a is ground or polished by the relative movement of the spherical surface 70b with respect to the rotating processing surface 10a.

  The processing time set at this time may be always constant, or the control unit 52 may change the processing time based on the measured thickness value and the set value. In this case, actual measurement data representing the correlation between the processing time and the thickness may be acquired in advance, and the processing time may be automatically adjusted based on the actual measurement data and the measured thickness value.

  In addition, when the optical element material 10 and the processing tool 70 are brought into contact with each other at the start of processing or separated from each other after the processing ends, the optical element material 10 side may be moved along the axis R1. The 70 side may be moved along the axis R1 or the axis R2, or both may be moved.

  According to the fourth embodiment, even when a spherical tool is used as a processing tool, the thickness of the optical element material can be measured at any time during the processing of the optical element material. A high optical element can be manufactured.

DESCRIPTION OF SYMBOLS 1, 2, 4 Optical element manufacturing apparatus 10 Optical element material 10a Processing surface 11 Optical element holder 11a Holding part 11b Recessed part 11c Support part 11d Bottom part 11e Through-path 12 Spindle 13 Motor 14 Belt 15 Support mechanism 20, 70 Processing tool 20a, 70a Concavity 21 Processing tool support device 30 Measurement unit 31 Light source 32 Prism 33 Reference mirror 34 Mirror support device 35 Imaging device 36 Measurement processing unit 40 Display unit 50, 60 Processing control unit 51 Input unit 52, 62 Control unit 53 Motor control unit 54 Position control unit 55 Motion control unit 61 Determination unit 70b Concave spherical surface

Claims (11)

Holding means for holding the optical element material;
A processing tool support means for supporting a processing tool that contacts the processing surface of the optical element material and grinds or polishes the optical element material;
A motion mechanism for providing a relative motion between the optical element material held by the holding means and the processing tool supported by the processing tool support means;
A measuring means for measuring the thickness of the optical element material in a non-contact manner provided on the opposite side of the processing tool supported by the processing tool support means with respect to the optical element material held by the holding means; ,
An optical element manufacturing apparatus comprising: The measuring means includes
A light source provided on the opposite side of the processing tool supported by the processing tool support means with respect to the optical element material held by the holding means;
An optical system for causing light emitted from the light source to be incident on a surface opposite to the processing surface of the optical element material held by the holding unit;
Measurement processing means for measuring the thickness of the optical element material based on the light reflected by the optical element material;
The optical element manufacturing apparatus according to claim 1, comprising: The light source is a light source that emits low coherence light,
The optical system is
The light emitted from the light source is divided into measurement light parallel to the optical axis of the optical element material held by the holding means and reference light having an optical path orthogonal to the measurement light, and the measurement light is divided into the optical light A light splitting means for making it incident on a surface of the element material opposite to the processed surface;
A reference mirror having a reflecting surface orthogonal to the optical path of the reference light, and movable along the optical path of the reference light;
Have
The measurement processing means measures the thickness of the optical element material according to the principle of spectral interferometry based on the measurement light reflected by the optical element material and the reference light reflected by the reference mirror.
The optical element manufacturing apparatus according to claim 2.   The holding means is a holder that holds the optical element material, and is provided with a through path that allows light emitted from the light source to pass toward a surface opposite to the processing surface of the optical element material. The optical element manufacturing apparatus according to claim 2, further comprising a holder.   The optical element manufacturing apparatus according to claim 1, further comprising a notification unit that notifies the thickness measured by the measurement unit.   6. The apparatus according to claim 5, further comprising a control unit that stops the operation when a predetermined time has elapsed from the start of the operation of grinding or polishing the processed surface, and causes the measurement unit to measure the thickness. The optical element manufacturing apparatus according to 1. Control means for stopping the operation and measuring the thickness by the measurement means when a predetermined time has elapsed from the start of the operation of grinding or polishing the processed surface;
Determining means for determining whether the thickness is equal to or less than a predetermined set value;
Further comprising
When the thickness is equal to or less than the set value, the control means moves at least one of the processing tool and the optical element material so that the processing tool and the processing surface of the optical element material are separated from each other. The optical element manufacturing apparatus according to any one of claims 1 to 4, wherein the control is performed to move the optical element. Determining means for determining whether the thickness measured by the measuring means is equal to or less than a predetermined set value;
When the thickness is equal to or less than the set value, the operation of grinding or polishing the processing surface is stopped, and the processing tool and the processing surface of the optical element material are separated from each other. Control means for performing control to move at least one of the optical element materials;
The optical element manufacturing apparatus according to claim 1, further comprising: Further comprising notification means for notifying information relating to the manufacture of the optical element,
9. The optical element manufacturing apparatus according to claim 7, wherein the control unit causes the notification unit to notify the end of processing when the thickness is equal to or less than the set value.   The optical element manufacturing apparatus according to claim 5 or 9, wherein the notification means performs notification by at least one of screen display, lighting or blinking, sound output, and notification sound output. A holding step for holding the optical element material in the holding means;
A processing step of grinding or polishing the processing surface by rotating at least one of the holding means and the processing tool;
The thickness of the optical element material is measured in a non-contact manner in a state where the processing tool is in contact with the processing surface by a measuring means provided on the side opposite to the processing tool with respect to the optical element material. Measuring process;
An optical element manufacturing method comprising:

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