JP5065862B2 - Luminous flux measuring device - Google Patents

Description

The present invention relates to an optical flux measurement device, particularly those precisely measure the parallelism of the parallel light beam to be used in various optical devices, and in FIG Re so that the accuracy by unifying the quality of the parallel beam.

A wide variety of optical devices using parallel light beams have been put into practical use. For example, an autocollimator and an illumination system of an apparatus that exposes various patterns are known. In these devices, if the parallel accuracy of the parallel light beam is increased, the accuracy of the entire device is improved. Therefore, various devices are used to obtain a highly accurate parallel light beam. For example, when a parallel light beam is obtained by using a plurality of lens groups, how to accurately align the optical axes of the plurality of lens groups is one of the specific means for improving the parallel accuracy of the light beam. It has become one.
In addition, in order to improve the accuracy of parallel light flux by taking measures against spherical aberration between multiple lenses or lens groups and heat countermeasures for the entire device, a specific lens or lens group is moved in the optical axis direction. Some of them are managed by managing the movement method (Patent Documents 1 and 2). In the optical scanning device and various exposure apparatuses, the size of the image projected on the exposure surface (projection surface) is measured at the front side (light source side) and rear side (exposure surface side) in the parallel light flux. A simple method is also adopted in which the accuracy of parallelism is determined by comparing the above. Furthermore, an angle measuring device is also known that is less susceptible to disturbances such as vibrations and temperature changes as in Patent Document 3. According to this Patent Document 3, a parallel light beam LE is emitted toward the first reflecting surface of the object to be measured, and the reflected light is directed to the second reflecting surface 22 arranged at right angles to the first reflecting surface 21, When the reflected light from the two reflecting surfaces 22 reaches the imaging position, the amount of deviation d at the imaging position is obtained to obtain the tilt angle of the object to be measured.
JP 2005-31068 A JP-A-9-138373 JP-A-9-113243

However, each of these conventional ones only discusses the parallelism of the entire light beam that has passed through the lens or lens group employed to obtain a parallel light beam, and a plurality of them in a plane perpendicular to the optical axis in one parallel light beam. It is not done to divide the location and discuss the parallelism of each division. The right of the light beam in the lens entrance surface of the parallel light beam passing through the for example one lens, the left side of the light beam, measured that either the middle part beams is kept similar parallelism, it could not be compared It was. This has made it difficult to unify the quality of the parallel light flux used in various optical instruments and to guarantee its reliability accurately.

Accordingly, an object of the present invention is to solve the above problems and extract a parallel light beam used in various optical devices by dividing it into a plurality of planes perpendicular to the optical axis and measure the parallelism of the extracted light beams. Is to do. Right of the light beam also the left of the light beam in which the lens surfaces of the parallel light beam passing through any lens example also, the intermediate portion light beam also ing to be compared by measuring the parallelism in the same way. In addition, this makes it possible to simplify the optical axis alignment of multiple lenses and to study spherical aberration, so that the quality of the collimated light beam from the optical device that is the subject as a whole can be unified and the reliability can be improved. It is to be.

In order to solve the above problems, the present invention
It is installed so as to orthogonal to the optical beam from the optical unit, a pinhole plate provided with pin holes in the central optical axis position and the peripheral multiple positions in the optical unit, each pinhole image behind the pinhole plate A photometric unit containing a light receiving unit arranged so as to be able to project , and coordinates of a position where a light beam parallel to the central optical axis that has passed through each pinhole provided in the pinhole plate is projected onto the light receiving unit. An origin memory for storing the origin on the unit, a display unit for displaying a signal from each light receiving unit in the photometry unit, and each origin stored in the origin memory for a signal from each light receiving unit in the photometry unit is displayed. A control unit that controls the display position so that it is the ideal origin on the part, and the positional difference between the ideal origin displayed on the display part and each pinhole image Ri, characterized in that to be able verify parallelism with respect to the central optical axis of the light beam that has passed through the optical unit.
In this light beam measuring apparatus, the light receiving unit in the photometric unit is provided corresponding to each pinhole in the pinhole plate, and the control unit is configured such that the origin of each light receiving unit is overlapped as a common origin on the display unit. The display control of the signal from the light receiving unit is performed so that it is displayed, and the light receiving unit installed corresponding to each pinhole of the pinhole plate is configured by PSD (Position Sensitive Device) It is characterized by.
According to the present invention, the light receiving unit in the photometric unit is configured by one CCD (Charge Coupled Device) arranged so that all the pinhole images on the pinhole plate can be projected, and the control unit is provided in each pinhole. The display control of the signal from the light receiving unit is performed while the display position is controlled so that the corresponding origin becomes the ideal origin position on the display unit .
The present invention, one of the optical unit and the metering unit, characterized in that to be able to rotate relative to the other party.

In the present invention , light from a light source is converted into a parallel light beam by an optical unit as a subject, directed to a light receiving unit via a pinhole plate having a plurality of pinholes, and transmitted to a display unit as a pinhole passing light beam signal for display. . At this time, the parallel luminous flux from the subject is extracted by being divided into a number corresponding to the number of pinholes of the pinhole plate and is directed to the light receiving unit. If each pinhole passing luminous flux is an accurate parallel luminous flux, The pinhole passing light beam signal can be displayed superimposed on one display origin determined by the display unit. If there is a defect in the parallelism of the light beam passing through the pinhole, the light signal passing through the pinhole is displayed out of the overlapping point. In the present invention, by adjusting the inside of the optical unit while checking the displayed pinhole passing light beam on the display unit, the pinhole passing light beam signal can be adjusted so as to be displayed superimposed on one place. Ru Monodea you. Accordingly, the optical unit that generates the defective light beam can be easily adjusted while checking the display unit. Further, by measuring the amount of deviation displayed on the display unit, the parallelism for each pinhole passing light beam can be measured. Thus, it becomes possible to divide and extract one parallel light beam output from the subject, which has been difficult to capture until now, and measure each of them. For example, the right side of the lens surface in the subject can be measured. The parallelism can be measured and compared in the same manner for the light flux that has passed through, the light flux that has passed through the left side, and the light flux that has passed through the intermediate portion. In addition, when a plurality of lenses or lens groups are used for the subject, the amount and direction of displacement of each lens or lens group can be known, so that simplification of optical axis alignment and correction of spherical aberration can be studied. As a whole, the quality of the parallel luminous flux output from the optical device as the subject can be unified, and the reliability can be made high.

A light flux measuring apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing the overall configuration of a light beam measuring apparatus according to the present invention. A light source 2 described in FIG. Is housed. The parallel light flux that has passed through the collimator lens 3 is directed to the photometric unit 4. The photometric unit 4 also accommodates a pinhole plate 5 which will be described with reference to FIG. 2 and a light receiving portion 7 onto which a light beam passing through a plurality of pinholes 6 provided in the pinhole plate 5 is projected. The light beam projected on the light receiving unit 7 is transmitted from the control unit 8 to the display unit 9 and displayed as a pinhole passing light beam signal. The parallel light flux from the optical unit 1 is determined by confirming the displayed pinhole passing light flux. A drive unit 10 is attached to the optical unit 1 and operates to move the position of the collimator lens 3 with respect to the pinhole plate 5 of the photometry unit 4 in the optical axis direction.

FIG. 2 is a diagram illustrating the optical unit 1 and the photometry unit 4 of FIG. Laser light from the laser light source 2 passes through the lens 11 and the pinhole 12 toward the collimator lens 3, and becomes a parallel light beam toward the pinhole plate 5 in the photometric unit 4. The pinhole plate 5 is installed so as to be orthogonal to the parallel light flux from the optical unit 1, and a plurality of pinholes 6 are provided as shown in the front view of the pinhole plate 5 in FIG. 2B. In this example, the position where the pinhole 6 is disposed is paired with a central optical axis 13 position (6a) and a peripheral position (6b to 6e) which is symmetric about the central optical axis 13 position with a pitch p. Are arranged at multiple locations. The parallel luminous flux from the collimator lens 3 that has passed through the pinhole 6 is directed to the light receiving unit 7 corresponding to each pinhole 6. That is, the collimator lens portions facing the light beams passing through the pinholes 6 become photometric points 3a to 3e, and the light beams from the photometric points 3a to 3e pass through the pinholes 6a to 6e and become pinhole-passing light beams 14a to 14e. It goes to the light receiving unit 7.

The light receiving unit 7 is arranged behind the pinhole plate 5 in parallel with the pinhole plate 5 and is configured by PSD (Position Sensitive Device) installed corresponding to each pinhole 6. In this example, five PSDs 7a to 7e are installed corresponding to the five pinholes 6a to 6e, and the pinhole passing light beams 14a to 14e from the photometry points 3a to 3e are projected toward the corresponding PSDs 7a to 7e, respectively. . Pinhole passing light fluxes 14a to 14e received by the PSDs 7a to 7e are transmitted to the control unit 8 as pinhole passing light flux signals (hereinafter referred to as pinhole image signals). The control unit 8 accommodates a signal processing circuit, an A / D conversion circuit, and the like that receive signals from the light receiving unit 7 and perform various processing. Further, the control unit 8 accommodates origin memories corresponding to the PSDs 7a to 7e, which will be described later. The pinhole image signal transmitted to the control unit 8 is transmitted to and displayed on the display unit 9 of FIG.
The collimator lens 3 installed in the optical unit 1 is accommodated in a lens barrel 15 or the like, and the lens barrel 15 is connected to the drive unit 10. When the driving unit 10 is operated, the lens barrel 15 moves in the direction of the optical axis 13 and changes the position of the collimator lens 3 with respect to the pinhole plate 5. The collimator lens 3 is shown as a monocular lens in the example of FIG. 2, but there is a lens composed of a plurality of lenses and a lens group composed of a plurality of lens groups. The optical unit 1 may contain various diaphragms and other necessary optical members in addition to those shown in the drawing, but these are general ones and are omitted.

FIG. 3 shows where the luminous flux parallel to the central optical axis 13 that has passed through each pinhole 6 is projected on the elements 7 a to 7 e such as PSDs installed corresponding to each pinhole 6 constituting the light receiving unit 7. In order to confirm, the light projecting unit 16 and the light metering unit 4 which are installed in advance instead of the optical unit 1 of FIG. 1 are described, and the light beam from the light projecting unit 16 is projected onto the light receiving unit 7 of the light metering unit 4, The projection position coordinates are stored in the origin memory in the control unit 8 as the display origin. The light projecting unit 16 includes a light projecting unit 17, driving units 18 and 19 for translating the light projecting unit 17 in the X and Y directions, and a connection between the driving units 18 and 19 and the light projecting unit 17. The precision feed mechanism 20 is stored. The light projecting unit 17 accommodates a laser light source 21, a lens 22, a pinhole 23, and the like, and laser light from the laser light source 21 is provided on the pinhole plate 5 of the photometry unit 4 by the driving units 18 and 19 and the feeding mechanism 20. It is prepared so as to correspond to each pinhole 6 position. In the illustrated example, the light projecting unit 17 is set at a position corresponding to the pinhole 6b of the pinhole plate 5, and the passing light beam 24b is projected onto the light receiving unit (PSD) 7b. At this time, the light beam 24 b is projected as a light beam parallel to the central optical axis 13 in FIG. 2 at the center coordinate position of the PSD 7 b, for example, the “X0, Y0” position, and the position of the light receiving unit 7 b or the position of the light projecting unit 17. Is adjusted. However, it is also predicted that, for example, “X−1, Y + 1” will be the projection point position of the light receiving unit 7b due to an adjustment error or the like. Even in such a projection point position, the position “X−1, Y + 1” is stored in the origin memory in the control unit 8 as the display origin.

Next, the light projecting portion 17 is translated to a position indicated by 17a and set to a position corresponding to the pinhole 6a. Then, the output light from the light projecting unit 17 passes through the pinhole 6a, becomes a light beam 24a, and is projected onto the PSD 7a. At this time, the feed mechanism 20 is accurately managed so that the output lights 24b and 24a are parallel. Thus, when the projection position 17a and the setting position of the PSD 7a are adjusted and the projection point position on the PSD 7a is obtained as, for example, “X0, Y0”, the position “X0, Y0” is used as the display origin in the control unit 8. Stored in the origin memory. Similarly, the light projecting unit 17 is translated to the position indicated by 17c and set to a position corresponding to the pinhole 6c. Then, the output light from the light projecting unit 17 passes through the pinhole 6c to become a light beam 24c, and is projected onto the PSD 7c as a light beam parallel to the light beams 24b and 24a. If the projection point position on the PSD 7c is, for example, “X-1, Y-2” even after adjusting the position 17c of the light projecting unit or the setting position of the PSD 7a, the position is set as the display origin. It is stored in the origin memory in the control unit 8. In the same manner, the light projecting unit 17 is set at a position corresponding to the pinholes 6d and 6e, and the display origin is obtained and stored in the origin memory.
General mechanisms such as a specific internal structure of the light projecting unit 16, a connection method with the photometric unit 4, and a method of mounting the lens barrel 15 containing the collimator lens 3 to the optical unit 1 are adopted. The description thereof is omitted here.

The relationship between the projection position of the light receiving unit 7 and the display origin as described above will be further described with reference to the explanatory diagram of FIG. 4A shows a state in which the output lights 24a to 24e from the light projecting unit 17 are projected onto the PSDs 7a to 7e in an ideal form, and FIG. 4B shows actual projection points 25a to 25e on the PSDs 7a to 7e. ing. FIG. 4C shows the stored contents of the origin memories 26 a to 26 e housed in the control unit 8. 4A and 4B, the squares of PSDs 7a to 7e indicate the light receiving surfaces of the respective PSDs, and the intersection of the alternate long and short dash lines indicates the center of the light receiving surface. For example the projection point 25a is projected to the position "X0, Y0" in PSD7a in Figure 4B, the display origin the value "X0, Y0" is stored in the origin memory 26a of FIG. 4C. The position of PSD7b in Figure 4B "X-1, Y + 1" projection point 25b of the light beam 24b projected on becomes the value "X-1, Y + 1" is stored in the origin memory 26b in FIG. 4C display origin . Projection point 25c of the projected light beam 24c similarly to the position of PSD7c "X-1, Y-2" will display the origin the value "X-1, Y-2" is stored in the home memory 26c. Similarly, the values of the projection points 25d and 25e are stored in the origin memories 26d and 26e and become the display origin. In FIG. 4C , the origin memories 26a to 26e are shown as separate ones, but it should be understood that they are stored in different areas in one memory.

FIG. 5 is an explanatory diagram when the projection point 25 is displayed as the pinhole image 27 on the display screen 9 a of the display unit 9 based on the display origin stored in the origin memory 26 by the control unit 8 . The control unit 8 performs control to display the data of the light receiving units 7a to 7e shown in FIG. 4B so as to overlap each other on the display unit 9, and FIG. 5A illustrates the center of the light receiving surface of the light receiving units 7a to 7e (FIG. 4B). The pinhole image 27 is displayed on the screen 9a based on the values from the origin memories 25a to 25e so that the intersections of the alternate long and short dashed lines overlap . Therefore, for example, the image 27a is displayed at the center coordinate position “X0, Y0” of the screen 9a, the image 27b is displayed at the “X-1, Y + 1” position of the screen 9a, and the image 27e is “X0” of the image 27a. , Y0 "position. However, since it is difficult to determine how much the pinhole passing light beam 14 is not parallel to the optical axis in this state , the control unit 8 determines the display coordinate position from each origin memory 26 as shown in FIG. 5A. The coordinate positions are changed so that all the pinhole images 27 are superimposed and displayed on the same center coordinate position “X0, Y0”. That is, the control unit 8 adds the X and Y correction offset values (values corresponding to FIG. 4C) to the values of the respective origin memories 26, and makes all the pinhole images 27a to 27e have the same coordinate position as shown in FIG. Adjustment is performed so that the image is superimposed on “X0, Y0”. For example, “+1, −1” is added to the value of the origin memory 26b, and “0, −1” is added to the origin memory 26d, and both are set to the “X0, Y0” position on the display screen 9a as the origin. Adjust so that is displayed. Thus, the pinhole image 27 dispersedly displayed on the screen 9a as shown in FIG. 5A is displayed superimposed on one central portion “X0, Y0” of the screen 9a as shown in FIG. 5B. The reference “X0, Y0” is referred to as a display origin (or ideal origin) . In FIG. 5, reference numeral 28 denotes a crosshair for identification displayed on the screen 9a.

  As described above, the display origin is stored in the origin memory 26 in advance using the reference parallel light beams 24a to 24e output from the light projecting unit 16, and all the pinholes are displayed at the display origin “X0, Y0” position on the display screen 9a. If the image 27 can be superimposed and displayed, the entire light projecting unit 16 in FIG. 3 is removed and the optical unit 1 as the subject is attached in association with the photometric unit 4. Since the collimator lens 3 and the like are accommodated in the optical unit 1 as the subject as described with reference to FIG. 2, the light flux from the optical unit 1 passes through the pinhole 6 and PSDs 7a to 7e as the light fluxes 14a to 14e. Projected on top.

FIG. 6 is an explanatory diagram showing the relationship between the optical unit 1 and the photometry unit 4 at this time. 6A is a diagram for explaining the position of the collimator lens 3 in the optical unit 1 with respect to the photometry unit 4, FIG. 6B is a diagram for explaining a projection point 25 on the PSD 7 of the pinhole image , and FIG. 6C is a pinhole image on the display screen 9a. FIG. In FIG. A, the collimator lens 3 in the optical unit 1 is set at a distance L1 with respect to the pinhole plate 5. The light beam that has passed through the collimator lens 3 is divided and extracted into five via the respective pinholes 6 and directed to the corresponding PSDs 7a to 7e. At this time , when the light beam that has passed through the collimator lens 3 is not parallel to the optical axis (for example, in a direction away from the optical axis), the pinhole plate 5 and the collimator lens 3 are located at a distance L1. The luminous flux from the lens 3 changes from the pinhole passing luminous fluxes 24a to 24e described in FIG. 3, the luminous flux 24b becomes 29b1 and changes its direction, and the luminous flux 24c becomes 29c1 and changes its direction. The luminous flux 24d is 29d1 and the luminous flux 24e is 29e1, and the directions are changed, and the luminous flux spreads uniformly and travels toward PSDs 7b, 7c, 7d, and 7e.
In the figure, the spread light beams 29b1 to 29e1 are shown as being changed by a distance d1 with respect to the projection points of the light beams 24b to 24e. The central light beam 24a is projected toward the PSD 7a as 24a without changing. FIG. 6B shows PSDs 7a to 7e on which pinhole images are projected by changing by the distance d1, but for simplification of explanation, PSDs 7a to 7e shown here are image positions from the PSD as shown in FIG. 5B. by adding the offset value mentioned above to the signal, it is shown in a state in which each of the origin (the intersection of the dashed line) is displayed origin projection point 25a gave a deviation d1 generated by the distance L1 thereon, 25B1～25e1 It is shown as

Thus, the signals of the projection points 25b1 to 25e1 by the pinhole passing light beams projected on the PSDs 7b to 7e with the deviation d1 are sent to the display unit 9 by the control unit 8 and displayed on the screen 9a. This displayed state is shown in FIG. 6C. In FIG. 6C, as described above, a case where the light beam that has passed through the collimator lens 3 is not parallel to the optical axis (for example, is directed away from the optical axis) is shown, and each pinhole image 27b1 to 27e1 is shown. Are dispersed from the center image 27a (display origin) by the amount corresponding to the shift amount d1 in FIG.
When the collimator lens 3 in the optical unit 1 as the subject is set at the position L1 with respect to the pinhole plate 5 as described above, the light beam that has passed through the collimator lens 3 is the reference in FIG. 3 except for the central light beam 24a. It changes from the parallel light beams 24b to 24e to the light beams 29b1 to 29e1 in the direction of spreading uniformly. Accordingly, on the display screen 9a, the pinhole images 27b1 to 27e1 to be displayed superimposed on the display origin 27a are displayed in a dispersed manner. By confirming the displayed screen 9a, it is determined that the light beam emitted from the collimator lens 3 is not in a parallel state. The control unit 8 measures the amount of deviation d1 from the display origin 27a. The measurement is performed with reference to the display origin stored in each origin memory 26 and the offset value for display position correction.

As described above, the light beam from the collimator lens 3 set at the L1 position is confirmed on the screen 9a, and the projected points 25b1 to 25e1 images from all the peripheral light beams 29b1 to 29e1 excluding the central light beam 24a If it is confirmed that they are displayed at different positions, it is determined that the set collimator lens 3 is in a poor position, and adjustment of the subject 1 is requested. In order to meet this requirement, the driving unit 10 in FIG. 1 is operated to move the lens barrel 15 along the optical axis 13 and approach the pinhole plate 5 side. FIG. 7 shows this approaching state.

7 illustrates the positional relationship between the position of the collimator lens 3 in the optical unit 1 and the photometry unit 4 as in FIG. 6. In FIG. A, the collimator lens 3 is L2 (L1> L2 with respect to the pinhole plate 5). In this example, the luminous flux that has passed through the collimator lens 3 is divided and extracted into five via each pinhole 6 and travels toward the corresponding PSDs 7a to 7e. At this time, since the pinhole plate 5 and the collimator lens 3 are located at a distance L2, the light beam that has passed through the collimator lens 3 is not parallel to the optical axis, and is, for example, a direction approaching the optical axis as opposed to the case of FIG. If towards, changing the pin hole passing beam 29b1~29e1 described in FIG. 6, the light beam 29b1 changes the direction becomes 29b2, the light beam 29c1 is 29C2, the light beam 29d1 is 29D2 light beam 29e1 is 29e2 The direction is changed, and the light flux is uniformly converged and directed to each PSD 7b, 7c, 7d, 7e. The converged light beams 29b2 to 29e2 are shown as being changed by a distance d2 with respect to the projection points of the light beams 24b to 24e. The central light beam 24a is projected as it is toward the PSD 7a.
FIG. 7B shows PSDs 7b to 7e in which the projection points 25b2 to 25e2 are changed. 7B is also shown as projection points 25a and 25b2 to 25e2 in which the deviation d2 generated by the collimator lens 3 at the L2 position is given to the projection point 25 to which the offset value is added as in FIG. 6B.

As is apparent from FIG. 7B, the positions of the projection points 25b2 to 25e2 on the PSDs 7b to 7e are opposite to those in FIG. 6B with respect to the center point 25a. For example, the projection point 25b1 in FIG. 6B is located above the center point in the figure, whereas the projection point 25b2 in FIG. 7B is located below the center point 25a. Similarly, the projection point 25e1 in FIG. 6B is located on the right side of the center point 25a, while the projection point 25e2 in FIG. 7B is projected on the left side of the center point 25a. This is because the setting position of the collimator lens 3 has moved from L1 to L2.

The projection points 25b2 to 25e2 thus projected onto the PSDs 7b to 7e with the deviation d2 are sent to the display unit 9 by the control unit 8 and displayed on the screen 9a. This displayed state is shown in FIG. 7C. In FIG. 7C, the pinhole images 27b2 to 27e2 are displayed while being dispersed from the central image 27a (display origin) by an amount corresponding to the shift amount d2 in FIG.
When the collimator lens 3 is set at the position L2 with respect to the pinhole plate 5 as described above, the light beam that has passed through the collimator lens 3 is uniform from the reference parallel light beams 24b to 24e in FIG. 3 except for the central light beam 24a. Changes to light beams 29b2 to 29e2 in a direction converging to. Accordingly, on the display screen 9a, pinhole images 27b2 to 27e2 to be displayed superimposed on the display origin 27a are displayed in a dispersed manner. By confirming the displayed screen 9a, it is determined that the light flux from the collimator lens 3 is not in a parallel state. The control unit 8 measures the amount of deviation d2 from the display origin 27a, and the measurement is performed with reference to the display origin stored in each origin memory 26 and the offset value for display position correction.

As described above, the light beam from the collimator lens 3 set at the L2 position is confirmed on the screen 9a, and the projection points 25b2 to 25e2 from the total light beams 29b2 to 29e2 excluding the central light beam 24a are the predetermined display origin 25a. If it is confirmed that they are displayed at different positions, it is determined that the set position of the collimator lens 3 as the subject is defective. 2 is operated to move the lens barrel 15 along the optical axis 13 and move away from the pinhole plate 5. FIG. 8 is an explanatory diagram showing this state.

FIG. 8 is a diagram for explaining the relationship between the position of the collimator lens 3 in the optical unit 1 and the photometric unit 4 as in FIGS. When the collimator lens 3 is set at a distance of Ln (L1> Ln> L2) with respect to the pinhole plate 5 as shown in FIG. A, the light beam that has passed through the collimator lens 3 is divided into five through each pinhole 6. Extracted and headed to the corresponding PSD 7a-7e. At this time, the pinhole passing light beams 29b2 to 29e2 shown in FIG. 7 gradually approach the reference passing light beams 24b to 24e in FIG. Therefore, the projection points 25b2 to 25e2 on the PSDs 7b to 7e also gradually approach the origin position 25a as shown in FIG. 8B. In FIG. 8B, each projection point 25b2 to 25e2 in FIG. 7B is represented by two crosses and represents a state of approaching the origin 25a. The process in which the projection points 25b2 to 25e2 approach the central display origin 25a can be confirmed by the pinhole images 27b2 to 27e2 approaching the origin 27a on the display screen 9a in FIG. 8C. In FIG. 8C, two crosses are used to represent the moving images 27b2 to 27e2.

Thus, when all the pinhole images 27a to 27e are superimposed and displayed at the intersection of the cross line 28 on the display screen 9a, the operation of the drive unit 10 is stopped and the position of the lens barrel 15 containing the collimator lens 3 is set to the optical unit 1. Fix against. That is, when the collimator lens 3 is set at a position of the distance Ln with respect to the pinhole plate 5, the luminous flux divided and output from the collimator lens 3 coincides with the reference pinhole passing luminous flux 24 and is divided and extracted. It is determined that all of the output light beams become parallel light beams. Then, each of the photometric points 3a to 3e of the optical unit 1 that accommodates the collimator lens 3 is assumed to have guaranteed accuracy, and the light flux measurement operation is completed.
In the example described above, the relationship between the optical unit 1 and the photometric unit 4 is adjusted by the distance L between the collimator lens 3 and the pinhole plate 5. That is, the relationship between the optical unit 1 and the photometric unit 4 is adjusted by setting the distance L1 in FIG. 6 to the distance L2 in FIG. 7 or the distance Ln in FIG. However, in addition to such an example, the same adjustment as in the above L can be performed even if the installation angle of the collimator lens 3 is changed or the distance between the lenses is changed when the lens has a compound eye configuration. . Even if the angle or the distance between the lenses is changed, the change process can be sequentially confirmed on the display screen, so that it can be handled in the same manner as the adjustment of the distance L. Therefore, in the present application, the expression “adjustment of the distance L” includes the change of the angle of the collimator lens and the change of the distance between the lenses, and is expressed as adjusting the inside of the optical unit 1. The optical unit 1 that has been adjusted in this way and passed the inspection work and passed the inspection is used by being incorporated into an autocollimator, for example.

  In the above example, the positions of the pinholes 6b to 6e described with reference to FIG. 2B are symmetric with respect to the central pinhole 6a, and the deviations d1 and d2 described with reference to FIGS. It was a case where it was constant. However, when a part of the pinhole passing light beam 29 is changed, for example, the direction of deviation of the light beam 29c1 in FIG. 6 is opposite, the amount thereof is d2, and the direction of deviation of the light beam 29c2 in FIG. On the other hand, it also occurs when the amount is d1. In such a case, the images 27c1 and 27c2 on the display screen 9a corresponding to the light beams 29c1 and 29c2 are displayed at positions deviating from the central display origin 27a in FIG. 8C. From this display, it can be determined that some processing errors, scratches, dust adhesion, and the like have occurred at the collimator lens 3 photometry point 3c at the distance L1 position and the collimator lens 3 photometry point 3c at the distance L2 position. . If the distance between the display origin 27a on the screen 9a and the shifted images 27c1 and c2 is measured, the values of d1 and d2 can be measured. By confirming the display screen 9a in this way, it is possible to measure and compare the parallelism by dividing and extracting, for example, the right side beam, the left side beam, and the middle beam from the collimating lens 3 in the emitted light beam, Optical axis alignment and the like can be easily performed.

When the setting position of the collimator lens 3 is fixed in the optical unit 1 as described above, the optical unit 1 is removed and the optical unit 1 as the next subject is attached to the photometric unit 4. Then, the operation described with reference to FIGS. 6, 7, and 8 is performed to check the emitted light beam from the collimator lens 3, and the deviation d and the direction are measured.

FIG. 9 shows a modification of the pinhole plate 5. In the example of FIG. 2B, pinholes 6b to 6e are provided at a pitch p with the center pinhole 6a as the center. In FIG. 9, 6f-6i pinholes are further provided. If the number of pinholes 6 is increased as in this example and the light receiving portions 7 are installed correspondingly, the photometric points can be obtained as much. If a plurality of pinholes 6 are installed at positions that are symmetric with respect to the center pinhole 6a as shown in FIG. 2B and the example of FIG. The accuracy can be compared. Accordingly, for example, the accuracy of the spherical aberration of the collimator lens 3 can be examined.

  FIG. 10 is a diagram for explaining the second embodiment. The same elements as those in FIGS. The diameter of the collimator lens 3A is smaller than that in FIGS. 2 and 6 or the diameter of the light beam emitted from the collimator lens 3A is small between the photometric points 3b and 3e. The light beam that has passed through the collimator lens 3 </ b> A is directed to the pinhole plate 5 of the photometric unit 4. The pinhole plate 5 is provided with a plurality of pinholes 6 (for example, 6a to 6e) as in FIG. 2B, but the arrangement pitch is smaller than p in FIG. 2B so that it can correspond to the collimator lens 3A. It has become. The light beams 24a to 24e that have passed through the pinhole 6 are directed to the light receiving unit 7A configured by one CCD. The pinhole 6 passing light beams 24 a to 24 e received by the CCD 7 A are sent to the control unit 8 as pinhole image signals and displayed on the display unit 9.

FIG. 11 is a diagram for explaining a CCD 7A as a light receiving unit. This CCD 7A is constituted by a single CCD to correspond to the collimator lens 3A having a small diameter, and the space for arranging the plurality of PSDs 7a to 7e as shown in FIG. 6A is reduced. When the reference pinhole passing light beams 24a to 24e (light beams parallel to the optical axis) based on FIG. 3 are projected onto the light receiving portion 7A, projection points 25a to 25e as indicated by black circles in the figure are obtained. However, each black circle projection point 25 is shown as a position corresponding to a desirable position (display origin (ideal origin) “X0, Y0”) as the theoretical value described in FIG. For example, when the upper left corner of the CCD 7A in FIG. 11 is X0 and Y0, the theoretical projection point 25b is “X11, Y4”, 25d is “X4, Y11”, 25a is “X11, Y11”,. , Y21 ". In the drawing, the theoretical projection point coordinates are shown as a column 31 in origin memories 26b, 26d, 26a, 26e, and 26c provided corresponding to the projection points 25. However, when the actual reference pinhole passing light beams 24a to 24e (light beams parallel to the optical axis) by the light projecting unit 16 are projected onto the CCD 7A, it is expected that each projection point 25 will have an error as indicated by a cross. The For example, the projection point 25b is "X10, Y5", ... 25d is "X4, Y12", ... 25c is "X10, Y20". The actual projection point coordinates (x marks) are shown in the column 32 of the origin memories 26a to 26e in FIG. 11 for reference.

When the display origin (black circle mark) is obtained and the actual projection by the reference pinhole passing light beams 24a to 24e is performed on the CCD 7A (x mark), the control unit 8 has (x mark) for each display origin (black circle mark). An offset value is obtained, added to the projection point coordinates (×), and stored in the origin memory 26, respectively. As a result, under the control of the control unit 8, the (x mark) can be displayed so as to coincide with the (black circle mark), and the calculated offset value is also used when obtaining the deviation amount.
When the display origin is obtained and stored in each origin memory 26, the light projecting unit 16 in FIG. 3 is replaced with the optical unit 1 in FIG. Then, as described with reference to FIG. 6, the distance between the collimator lens 3 and the pinhole plate 5 is set to L1, and the pinhole passing light beams 24a to 24e are projected onto the CCD 7A. The projection points 25a to 25e are, for example, as indicated by (Δ) in FIG. 11 , the projection point 25b is “X10, Y4”, 25d is “X3, Y10”, 25a is “X11, Y12”, and 25e is “X21, Y10”. , 25c is “X11, Y21” , the control unit 8 adds the above-described offset value, 25b is “X11, Y3”, 25d is “X3, Y9”, 25a is “X11, Y12”, 25e "X21, Y10", you and 25c as "X12, Y22". FIG. 12 shows an example when an image by this projection point (Δ mark) is displayed on the display screen 9a.

In FIG. 12, the screen 9a displays five display origins (black circles) and pinhole images 27a to 27e (Δ marks). In the example of FIG. 6C, one display origin 27a and a plurality of images 27b1 to 27e1 are displayed around the display origin 27a. In the example of FIG. 12, five display origins (black circles) and five pinhole images (Δ Is displayed. While confirming the display screen 9a operates the driving unit 10 of FIG. 10, moves along the collimator lens 3A to the optical axis 13, will shorten the distance between the pinhole plate 5 in the direction of L2. Then, the image point (Δ mark) gradually approaches the display origin (black circle mark) direction, and they are displayed in a superimposed manner in the vicinity of the distance Ln. When this superimposed display is confirmed on the screen 9a, it is determined that all five light beams emitted from the photometric points 3a to 3e of the collimator lens 3A are in a parallel state. If a light beam whose image point (Δ mark) and display origin (black circle mark) do not coincide with each other is generated, it is determined that there is an error such as spherical aberration or a flaw at the corresponding photometry point of the collimator lens 3A. Further, the shift amount d between the display images that do not coincide (Δ mark) and (black circle mark) can be measured by the control unit 8, but the direction can also be confirmed at the same time.
When the setting position of the collimator lens 3A is fixed in the optical unit 1 as described above, the optical unit 1 is removed and the optical unit 1 as the next subject is attached to the photometric unit 4. Then, the operation described with reference to FIGS. 6, 7, and 8 is performed to check the emitted light beam from the collimator lens 3A, and the shift amount d and the direction are measured.

FIG. 13 is an explanatory diagram of the third embodiment. In the figure, the optical unit 1 a rotates around the rotation shaft 36 by the operation of the drive unit 35. The collimator lens 3 is accommodated in the optical unit 1a as shown in FIGS. 2, 6 and 10, and the pinhole plate 5 and the light receiving part 7 as shown in FIGS. When the optical unit 1a rotates, the collimator lens 3 rotates, and when the collimator lens 3 rotates, the positions of the photometric points 3a to 3e corresponding to the pinholes 6 of the pinhole plate 5 also rotate. By this rotation, new photometric points, for example, 3b1 and 3b2, 3d1 and 3d2,... 3e1 and 3e2 can be obtained as shown in FIG. As the number of photometry points increases, the number of photometry light beams 24 also increases, so that the measurement density can be increased. Also, when the display origin 27 described with reference to FIG. 5B is determined, the number of samples to be compared increases, so that the averaged origin position can be obtained.
As described above, since the rotation of the optical unit 1 a is the rotation of the collimator lens 3, only the collimator lens 3 may be rotated by the drive unit 35 around the central optical axis 13.

FIG. 14 is an explanatory diagram showing a modification of FIG. 13 in which the photometry unit 4a is rotated instead of the optical unit 1 rotating. In the figure, the photometric unit 4a rotates around the rotation shaft 36 by the operation of the drive unit 35. Since the photometric unit 4a contains the pinhole plate 5 and the light receiving portion 7 as shown in FIGS. 2, 6, and 10, the rotation of the photometric unit 4a is the rotation of the pinhole plate 5 and the light receiving portion 7. When the pinhole plate 5 is rotated, the same result as that obtained by increasing the photometric points 3a to 3e is obtained as in the case where the collimator lens 3 of FIG. 13 is rotated. In FIG. 14B, 6b1 and 6b2, 6d1 and 6d2,... 6e1 and 6e2 are shown as new pinhole examples obtained by rotating the pinhole plate 5. The position of the collimator lens 3 corresponding to the new pinholes 6b1 to 6e2 becomes a new photometric point.
In the example of FIG. 14, since the entire photometric unit 4a is rotated, the pinhole plate 5 and the light receiving portion 7 are rotated together. Therefore, even if the positions of the pinholes 6b to 6e are changed as 6b1 and 6b2, 6d1 and 6d2,... 6e1 and 6e2, the light-receiving unit 7 rotates together, so that the work is not hindered. Conversely, when one light receiving portion 7A is used as in the example of FIG. 10, only the pinhole plate 5 needs to be rotated while the photometric unit 4a is fixed. When the entire photometric unit 4a is rotated, the pinholes 6a and 6h1 to 6hn of the pinhole plate 5 can be arranged randomly as shown in FIG. 14C. In this case, the photometry point of the collimator lens 3 is random according to the arrangement of the pinhole 6, and a new photometry point is obtained by rotating it.

  As in the third embodiment, one of the optical unit 1 and the photometric unit 4 can be rotated with respect to the counterpart, thereby increasing the photometric point. It is also possible to arbitrarily select a photometric point position divided and extracted from the collimator lens 3 as a light beam passing through a pinhole.

  As described above, the apparatus in which the optical unit 1 is the subject and the output light beam is divided and extracted, and the parallelism is measured for each of the divided and extracted pieces has been described. However, the connection method between the optical unit 1 and the photometric unit 4, the moving mechanism of the collimator lens 3 in the optical axis direction, the XY precision moving means of the light projecting unit, etc. are not described here because they are not directly related to the present invention. These may be general ones. The control unit 8 and the display unit 9 described in FIG. 1 and the like can be replaced with a general personal computer.

Schematic for description which showed the whole structure of the measuring apparatus. The figure explaining the optical unit and photometry unit of FIG. The figure explaining a light projection unit and a photometry unit. The figure explaining the relationship between a light-receiving part projection point position and a display origin. Explanatory drawing of the image displayed on a display screen. The figure explaining the relationship between an optical unit and a photometry unit. The figure explaining the relationship between an optical unit and a photometry unit. The figure explaining the relationship between an optical unit and a photometry unit. The figure which showed the example of the pinhole board. Explanatory drawing for demonstrating Example 2. FIG. Explanatory drawing of the light-receiving part comprised with CCD. Explanatory drawing of the image displayed on the screen of a display part. Explanatory drawing for demonstrating Example 3. FIG. Explanatory drawing for demonstrating Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical unit 2 ... Light source 3 ... Collimator lens 4 ... Photometry unit 5 ... Pinhole board 6 ... Pinhole 7 ... Light-receiving part 8 ... Control unit 9. ··· Display unit 13 ··· Center optical axis 14 ··· Pinhole passing beam 15 ··· Lens barrel 16 ··· Projection unit 17 ··· Projection unit 24 · · · Collimator lens exiting beam 25 ···・ Projection point 26 ... Origin memory 27 ... Pinhole image

Claims (5)

It is installed so as to orthogonal to the optical beam from the optical unit, a pinhole plate provided with pin holes in the central optical axis position and the peripheral multiple positions in the optical unit, each pinhole image behind the pinhole plate A photometric unit containing a light receiving unit arranged to project ,
An origin memory that stores, as an origin on the light receiving unit, coordinates of a position where a light beam parallel to the central optical axis that has passed through each pin hole provided on the pin hole plate is projected on the light receiving unit;
A display unit for displaying a signal from each light receiving unit in the photometric unit;
A control unit for controlling the display position so that the origin stored in the origin memory is the ideal origin on the display unit, the signal from each light receiving unit in the photometric unit;
The light beam characterized in that the parallelism with respect to the central optical axis of the light beam that has passed through the optical unit can be confirmed by the difference in display position between the ideal origin displayed on the display unit and each pinhole image. measuring device. The light receiving unit in the photometric unit is provided corresponding to each pinhole in the pinhole plate, and the control unit is configured so that the origin of each light receiving unit is displayed as a common origin on the display unit. The light flux measuring apparatus according to claim 1, wherein display control of a signal from is performed. Optical flux measurement apparatus according to claim 1 or 2, characterized in that to constitute a light receiving portion which is disposed in correspondence with each pin hole of the pin hole plate with PSD (Position Sensitive Device). The light receiving unit in the photometric unit is composed of a single CCD (Charge Coupled Device) arranged so that all the pinhole images on the pinhole plate can be projected, and the control unit has an origin corresponding to each pinhole. 2. The light flux measuring apparatus according to claim 1, wherein display control of a signal from the light receiving unit is performed while controlling the display position so as to be an ideal origin position on the display unit. The one of the optical unit and the light measuring unit, the light flux measuring device as claimed in any one of claims 1 to 4, characterized in that to be able to rotate relative to the other party.