JP2008170342A - Optical performance measuring apparatus and optical performance measuring method - Google Patents

Abstract

An object of the present invention is to measure the scratch resistance, antiglare property and antireflection property of a sample.
A scratch region is formed in a part of a sample. The sample 11 is set on the stage 12. The stage 12 is moved by the stage moving mechanism 14, and the sample 11 or the reference reflector 13 having a known reflectance is positioned selectively at the measurement position. The projector 15 irradiates the sample 11 or the reference reflector 13 with parallel light as inspection light at an incident angle θ1. The reflectance of the sample 11 is obtained by measuring the regular reflection light of the reference reflector 13 and the regular reflection light of the non-scratched region of the sample 11 by the light receiver 16. Further, the photoreceiver 16 is rotated around a measurement position within a predetermined angle range to measure the scratch area and the non-scratch area of the sample 11, and the value indicating the scratch resistance and the anti-glare property are obtained from the measurement results. Is obtained.
[Selection] Figure 1

Description

  The present invention relates to an optical performance measuring device and an optical performance measuring method for measuring optical performance of an antireflection film or the like.

  Many display surfaces of monitors such as computer monitors and televisions prevent reflection by diffusing and reflecting incident light incident on the surface of the display surface in order to improve the visibility of the displayed image. An antireflection film provided with antiglare properties (antiglare) and antireflection properties for reducing the amount of reflected light by causing reflected light to interfere with each other is provided.

As for anti-glare properties, for example, a method of forming an anti-glare layer having a fine uneven structure on the surface of a transparent film as in Patent Document 1 is known, and light transmissive diffusion materials such as silica and resin beads are light-transmitted. An antiglare layer is formed by applying a coating liquid dispersed in a conductive binder resin to the film surface. In addition, the reflectivity is realized, for example, by forming one or more thin film layers on the film surface, reflecting incident light on the front and back surfaces of the thin film layer, and interfering each other light to cancel each other. (For example, Patent Document 2).
JP 2002-182005 A Japanese Patent Application Laid-Open No. 11-174971

  In addition, it is important for the display surface of the display to have high anti-glare properties as well as anti-glare properties and anti-reflection properties. That is, since the surface of the display is wiped off dirt and dust attached in normal use, the antireflection film is required to have high scratch resistance (hardness). From such a background, anti-reflection films and the like are inspected for anti-glare properties and anti-reflection properties as well as scratch resistance. The conventional method for inspecting the scratch resistance is, for example, by directly rubbing the surface of the antireflection film to be inspected with an eraser or steel wool under an appropriate load, and visually evaluating how much the scratch has been made. Sensory evaluation was done.

  By the way, as described above, the antireflection film or the like performs various inspections such as an antiglare property and an antireflection function, but there is a problem that it is complicated and inefficient to inspect each of them separately. In addition, when performing visual inspections such as scratch resistance, the evaluation tends to vary due to individual differences among the inspectors, and even the same inspector tends to vary in the inspection results due to physical condition etc. was there.

  The present invention has been made to solve the above problems, and provides an optical performance measuring apparatus and an optical performance measuring method that can easily measure various optical performances of optical films and the like and can objectively evaluate them. The purpose is to do.

  In order to achieve the above object, in the optical performance measuring apparatus according to claim 1, a stage for holding the sample flat and an arbitrary portion of the sample held on the stage by moving the stage are measured positions. And a projection-side optical system that collimates the inspection light from the light source, and the inspection light from the light-projection side optical system is predetermined with respect to the surface of the sample placed at the measurement position. And a light receiving side optical system for extracting a light component parallel to the optical axis of the light incident from the optical axis direction, receiving the light extracted by the light receiving side optical system, A light receiving signal corresponding to the amount of light received, and a light receiving device provided so that the optical axis of the light receiving side optical system passes through the measurement position and is rotatable about the measurement position within the incident surface; and the inspection Predetermined with a rotational position to receive regular reflected light A rotation means for rotating the light receiver in a range of degrees, a total amount of light received when the light receiver is rotated in the predetermined angle range by the rotation means with respect to the scratch area, and a non-scratch area The total amount of light received when the light receiver is rotated within the predetermined angle range by the rotating means is determined based on the light reception signal from the light receiver, and the resistance of the sample surface is determined from the total amount of light received. A first calculation means for calculating a numerical value indicating the scratching property, and a half value of a peak value of the amount of received light based on a received light signal when the light receiver is rotated in the predetermined angle range with respect to the non-scratched region of the sample. And a second calculation means for obtaining a value relating to the antiglare property of the sample to be measured from the angular width.

  3. The optical performance measuring apparatus according to claim 2, wherein the moving means is configured to be able to move a reference reflecting plate having a known reflectivity provided on the stage to a measuring position, and the light receiving device is rotated in the regular reflection direction of the inspection light. The third calculating means is provided for obtaining the reflectance of the sample from the signal level of each received light signal of the reference reflecting plate and the non-scratched region in the state of the above and the reflectance of the reference reflecting plate.

  In the optical performance measuring apparatus according to claim 3, the light projecting side optical system and the light receiving side optical system are telecentric optical systems, and in the optical performance measuring apparatus according to claim 4, the projector is used to diffuse the inspection light. The light diffusion plate is removable.

  In the optical performance measuring method according to claim 5, a projector that irradiates the surface of the sample disposed at the measurement position with the inspection light made parallel light by the light projecting side optical system at a predetermined incident angle, and from the optical axis direction. It has a light receiving side optical system that extracts the light component parallel to the optical axis of the incident light, receives the light extracted by this light receiving side optical system, outputs a light receiving signal according to the amount of light received, and receives light The optical axis of the side optical system passes through the measurement position, and a light receiver that is rotatable around the measurement position in the incident surface is used to send inspection light to the measurement point in the scratch area formed on the sample. While irradiating, the light receiver is rotated within a predetermined angle range sandwiching a rotation position for receiving the specularly reflected light of the inspection light, and the amount of light received at each angle in the predetermined angle range is measured based on the received light signal. The first bending angle measurement step and the measurement point in the non-scratched area of the sample are detected. A second variable angle measuring step of rotating the light receiver within the predetermined angle range while irradiating light, and measuring the amount of light received at each angle in the predetermined angle range based on a received light signal; A scratch resistance calculating step for obtaining a numerical value indicating the scratch resistance of the sample based on the sum of the respective received light amounts obtained in the step of measuring the change of angle and the sum of the amounts of received light obtained in the step of measuring the second change of angle. Based on the received light amount obtained in the second variable angle measurement step, the angular width of the light receiver that is half the peak value of the received light amount is obtained, and the antiglare property of the sample to be measured is determined from this angular width. And an antiglare resistance calculating step for obtaining a value.

  7. The optical performance measurement method according to claim 6, wherein the light receiver is rotated to receive specularly reflected light of the inspection light at “2n + 1” (n = 1, 2,...) Measurement points in the scratch area. The first regular reflection light measurement step for measuring the amount of received light when the position is set, and the “2m + 1” (m = 1, 2,...) Measurement points in the non-scratched area are inspected by the light receiver. A second specular light measurement step for measuring the amount of light received when the rotational position for receiving the specular reflection light is received, and among the received light amounts obtained in the first specular reflection light measurement step Is the measurement point of the first variable angle measurement step, and the “m + 1” -th received light amount obtained in the second specular reflection measurement step. The measurement point that is the amount of received light is the measurement point of the second variable angle measurement step. A.

  The optical performance measurement method according to claim 7, wherein a reference reflection plate having a known reflectance is arranged at a measurement position, and the amount of light received is measured when the light receiver is in a rotational position for receiving regular reflection light of inspection light. Reference reflection measurement step, and a light receiving signal obtained in this reference reflection measurement step and a measurement point that is the “n + 1” -th received light amount of each received light amount obtained in the first regular reflected light measurement step And a reflectance calculating step for calculating the reflectance of the sample from each signal level of the received light signal and the reflectance of the reference reflecting plate.

  In the optical performance measuring method according to claim 8, the scratch region is formed by rubbing steel wool or plastic eraser on the sample surface. In the optical performance measuring method according to claim 9, the light projecting side optical system and The light receiving side optical system is a telecentric optical system. Furthermore, in the optical performance measuring method according to claim 10, parallel light is irradiated as inspection light on the sample in which the scratch area is formed by rubbing steel wool on the sample surface in the first and second deflection measurement steps. Instead of the projector, the projector that emits diffused light is used.

  According to the present invention, specularly reflected light is received by using a projector that irradiates the specimen with parallel inspection light at a predetermined incident angle and a light receiver that can rotate within the incident surface around the measurement position. Measure the amount of light received at each angle in a specified angle range across the rotation position for each measurement point in the scratch area and non-scratch area of the sample. The total amount of light received at the measurement points in the scratch area and non-scratch A numerical value indicating the scratch resistance of the sample is obtained based on the sum of the received light amounts at the measurement points in the region, and a numerical value indicating the antiglare property is obtained based on a change in the received light amount in a predetermined angle range with respect to the non-scratched region. Can be evaluated objectively.

  FIG. 1 shows an outline of a measuring apparatus embodying the present invention. The measuring device 10 measures the scratch resistance, antireflection property and antiglare property of the sample 11 which is a film to be inspected. On the upper surface of the stage 12, the sample 11 can be fixed and a reference reflector 13 is attached. The stage 12 is movable in a horizontal plane and is moved by the stage moving mechanism 14. By moving the stage 12, any point of the sample 11 and the reference reflector 12 can be moved to a measurement position by the projector 15 and the light receiver 16 to be a measurement point.

  As shown in FIG. 2, the sample 11 to be inspected has an antireflection film L2 having an antireflection function and an antiglare function formed on the surface of the transparent film L1, and the antireflection film L2 has an anti-reflection property. Measure scratch resistance, antireflection and antiglare properties. When it is necessary to measure the scratch resistance, a sample 11 in which a scratch area is partially formed is used as the sample 11 at the time of measurement. The sample 11 is not limited to that shown in FIG. 2, and various films can be used.

  A projector 15 that irradiates inspection light with a certain intensity toward the measurement position above the stage 12, and a light receiver 16 that receives the inspection light reflected by the surface of the sample 11 and the reference reflector 13 at the measurement position. Is arranged. The projector 15 is attached to the support member 18 and irradiates the sample 10 and the reference reflector 13 with inspection light so as to have an incident angle θ1 with respect to the horizontal plane. In this example, the stage 12 is arranged horizontally and the measurement is performed from above. However, these positional relationships are relative, and the stage 12 may be arranged vertically.

  The light receiver 16 is attached to the support member 18 via the angle adjuster 19, and is perpendicular to the inspection light reflected by the sample 11 and the reference reflector 13 (hereinafter referred to as reflection inspection light). The reflection inspection light emitted in the angle θ2 (hereinafter referred to as the light receiving direction angle) θ2 with respect to the normal plane, that is, the incident plane and the normal N of the horizontal plane is received.

  The angle adjuster 19 can change the light receiving direction angle θ <b> 2 of the light receiver 16 by rotating the light receiver 16 in the incident plane around the measurement position (measurement point). The light receiving direction angle θ2 is changed in a range of ± Δθ around the angle (θ2 = θ1) at which the inspection light regularly reflected by the sample 11 is received by the angle adjuster 19 in the angle change measuring operation described later. The angle adjuster 19 is driven by a drive motor 21.

  In this example, the incident angle θ1 is 30 °, Δθ is 5 °, and the light receiving direction angle θ2 is in the range of 25 to 30 ° and changes in 0.2 ° steps. It is important that the light projector 15 and the light receiver 16 receive the inspection light in an angle range sandwiching the angle at which the inspection light specularly reflected by the surface of the sample 10 is received. Moreover, although incident angle (theta) 1 is not limited to "30 degrees", it is preferable to set within the range of 20 degrees-45 degrees. Further, Δθ is not limited to 5 °, and can be appropriately set according to the characteristics of the sample.

  The control unit 22 comprehensively controls the measurement apparatus 10 to execute a measurement sequence. Based on the light reception signal from the light receiver 16, the evaluation unit 23 calculates values indicating the antireflection property, antiglare property, and scratch resistance of the sample 11.

  FIG. 3 shows the configuration of the projector 15. An LED (light emitting diode) 25 as a light source for inspection light is provided in the projector 15. The LED 25 outputs white light as inspection light. The color or wavelength of the inspection light can be arbitrarily selected, and the light source is not limited to the LED, and a lamp or the like may be used.

  In front of the LED 25, a plano-convex lens 26, a pinhole plate 27, a plano-convex lens 28, and a diaphragm plate 29 are arranged in this order from the LED 25 side. The optical axes of the plano-convex lenses 26 and 28 are coincident with each other, and the center of the pinhole 27a formed in the pinhole plate 27 and the aperture opening 29a formed in the diaphragm plate 29 is arranged on the optical axis. The angle formed by the optical axis of the plano-convex lenses 26 and 28 and the normal N is the incident angle θ1.

  The plano-convex lens 26 condenses the inspection light output from the LED 25. A pinhole 27a is arranged at a position where the inspection light is collected. The pinhole plate 27 and the plano-convex lens 28 constitute a well-known telecentric optical system in which the pinhole 27a is positioned at the front focal point of the plano-convex lens 28, and is parallel from the inspection light output from the LED 25. Take out the light and emit it. The aperture 29a adjusts the diameter of the inspection light beam. The inspection light that has passed through the aperture opening 29 a is irradiated from the projector 15 to the sample 11 or the reference reflector 13.

  Although the diameter of the pinhole 27a is 0.4 mm in this example, the parallelism of the extracted inspection light can be increased as the diameter is reduced. In addition, although the diaphragm opening 29a has a diameter of 3 mm, it can be set appropriately.

  FIG. 4 shows the configuration of the light receiver 16. The light receiver 16 includes a diaphragm plate 31, a plano-convex lens 32, a pinhole plate 33, a plano-convex lens 34, and a light receiving element 35 in order from the sample side. The optical axes of the plano-convex lenses 32 and 34 coincide with each other, and the centers of the aperture 26a and the pinhole 28a are arranged on the optical axes. The angle formed between the optical axis of the plano-convex lenses 27 and 29 and the normal line N is the light receiving direction angle θ2, and this optical axis passes through the measurement position.

  The diaphragm plate 31 is formed with a diaphragm opening 31a for adjusting the diameter of the received reflected inspection light beam. The reflected inspection light passing through the diaphragm opening 31a enters the plano-convex lens 32. The plano-convex lens 32 condenses the reflected inspection light from the aperture opening 31a. A pinhole 33a is arranged at the condensing position of the reflected inspection light by the plano-convex lens. The pinhole 33a and the plano-convex lens 34 are a telecentric optical system arranged so that the pinhole 33a is positioned at the front focal point of the plano-convex lens 34, and the optical axis of the reflected inspection light incident from the optical axis direction Extract parallel light components.

  The diameter of the aperture 31a is 1 mm, but can be adjusted as appropriate. Moreover, the parallelism of the reflected inspection light taken out can be increased as the diameter of the pinhole 33a is reduced. In this example, the diameter is set to 0.4 mm.

  The light receiving element 35 receives the reflected inspection light emitted from the plano-convex lens 34 and outputs a light reception signal having a signal level corresponding to the amount of light received. As the light receiving element 35, a PMT (photomultiplier tube) is used in this example, but various elements such as a photodiode and a phototransistor can be employed.

  FIG. 5 shows a state where the sample 11 is attached to the upper surface of the stage. On the upper surface of the stage 12, a reference reflecting plate 13 and a pair of sample frames 37 for positioning the sample 11 are provided. As the reference reflecting plate 13, a plate having a known reflectance is used, and the reflectance of the sample 11 is obtained based on the measurement result with respect to the reference reflecting plate 13.

  As the sample 11, a sample having a predetermined size, in this example, cut into a rectangle of 125 mm × 35 mm is used. The sample 11 is positioned by being pressed against each sample frame 37 and placed on the stage 12. Thus, a groove 39 is formed in the portion of the stage 12 on which the sample 11 is placed along the periphery of the sample 11, and a plurality of intake holes 39 a are provided at the bottom of the groove 39. is there. Each intake hole 39a is connected to an exhaust pump (not shown). Thereby, when the exhaust pump is operated after placing the sample 11 at a predetermined position on the stage 12, the sample 11 is adsorbed and fixed on the stage 12.

  The sample 11 has a scratched region 11a formed at substantially the center thereof, and the other region is a non-scratched region 11b. The scratch region 11a can be formed by various techniques. In this example, the surface of the sample 11 is formed by rubbing with a predetermined pressing force using “plastic eraser” or “steel wool”.

  If the inspection light is reflected on the back surface of the sample 11 or the surface of the stage 11 when the sample 11 is irradiated with the inspection light, the reflected light component becomes noise of the received light signal and accurate measurement cannot be performed. For this reason, it is preferable to make the reflectance sufficiently low, for example, by applying non-reflective coating to the back surface of the sample 11 or the surface of the stage 11. Moreover, the reflection which becomes noise can be effectively reduced also by sticking the adhesive sheet having a sufficiently low reflectance to the back surface of the sample 11.

  In this measuring apparatus 10, for one sample 11, a reference reflectance measurement sequence for the reference reflector 13, a scratch area measurement sequence for the scratch area 11a, and a non-scratch area measurement sequence for the non-scratch area 11b are performed. Further, as a measurement operation, for one measurement point, a regular reflection light measurement operation in which the light reception direction angle θ2 is set to the same size as the incident angle θ1 and the reflected inspection light that is regularly reflected is measured, and a predetermined angle range, that is, There is a variable angle measurement operation in which the light receiving direction angle θ2 is changed in the range of “θ1−Δθ” to “θ1 + Δθ” and the reflection inspection light is measured for each angle.

  The reference reflectance measurement sequence is a sequence for acquiring the amount of received light with respect to a known reflectance. The reference reflector 13 is moved to the measurement position, the specular reflection light measurement operation is performed on the reference reflector 13, and the received light signal is received. Signal level (hereinafter referred to as light reception signal level).

  Both the scratch area measurement sequence and the non-scratch area measurement sequence include a first subsequence for performing specular reflection light measurement operation for each of a plurality of measurement points arbitrarily selected from the area corresponding to the sequence, and the first subsequence. And a second sub-sequence for performing the variable angle measurement operation on one representative measurement point determined from the measurement results of (2).

  FIG. 6 shows the evaluation unit 23 as a functional block. The representative point determination unit 23 a determines a representative measurement point based on the light reception signal level of each measurement point obtained in the first subsequence, and sends information on the representative measurement point to the control unit 22. The control unit 22 moves the stage 12 via the stage moving mechanism 14 so that the representative measurement point becomes a measurement point in the second subsequence.

  By measuring a plurality of measurement points as described above and determining one representative measurement point from them, dust or the like is caught under the sample 11 when the sample 11 is attracted to the stage 12 and fixed. In other words, measurement of measurement points where correct measurement is not performed is eliminated, and representative measurement points that can be measured appropriately are determined. Various methods can be used for determining the representative measurement point. In this example, the specular reflection light measurement operation is performed for 15 measurement points, and the eighth level from the center of the level, that is, the larger (or smaller) level. The measurement point at which the received light signal level is the representative measurement point.

  Note that the number of measurement points is not limited to 15. For example, in the scratch area, the “2n + 1” (n = 1, 2,...) Measurement points are subjected to the specular reflection light measurement operation and obtained. Of the 2n + 1 ”received light amounts, the measurement point that is the“ n + 1 ”th received light amount may be determined as the representative measurement point. Similarly, in the non-scratched area, the specular reflection light measurement operation is performed on “2m + 1” (n = 1, 2,...) Measurement points, and the measurement point that has the “m + 1” -th received light amount is determined. What is necessary is just to determine to a representative measurement point. Further, the number of measurements in the scratch area and the non-scratch area may be different. The number of measurement points may be small, but it is preferable to determine one representative measurement point from 15 or more measurement parameters. Furthermore, which position is to be used as the measurement point may be determined in advance, for example, by selecting an appropriate position arbitrarily selected, or at random each time. Further, in order to exclude measurement points where correct measurement is not performed, the representative measurement points may be determined by other methods.

  The reflectance calculation means 23b calculates the reflectance as a value indicating the antireflection property of the sample 11, and the received light signal level of the representative measurement point determined in the first subsequence of the non-scratch region measurement sequence, and the reference The reflectance of the sample 11 is calculated using the received light signal level obtained by the reflectance measurement sequence and the known reflectance of the reference reflector 13. Specifically, the reflectance of the sample 11 is Rm, the reflectance of the reference reflector 13 is Rs (%), the received light signal level obtained by the regular reflected light measurement operation of the reference reflectance measurement sequence is Vs, and the non-scratch region When the received light signal level obtained by the regular reflected light measurement operation for the representative measurement point 11b is Vm, the reflectance is calculated by the reflectance calculation formula “Rm = Rs · (Vm / Vs)”.

  The sensory value calculation unit 23c calculates a value indicating the scratch resistance of the sample 11 (hereinafter referred to as a scratch sensory value). The sensory value calculation means 23c calculates the sum of the received light signal levels obtained in the second sub-sequence of the scratch area measurement sequence S1 and the sum of the received light signal levels obtained in the second sub-sequence of the non-scratched area measurement sequence. When S2, the scratch sensory value P is obtained by the sensory value calculation formula “P = (S1−S2) / S2”.

  The scratch resistance indicates how easy it is to attach, and this can be said to be the degree of scratching of the scratch area when the scratch area is formed under certain conditions. As shown in FIG. 7, in the scratch area 11a, the higher the degree of scratch, the weaker the antireflection and the intensity of reflected light becomes. Therefore, the light receiving direction angle θ2 of the scratch area 11a and the light intensity (light receiving amount) A curve Ca indicating the relationship is above the curve Cb of the non-abrasion region 11b. The ratio of the difference between the integral value of the curve Ca and the integral value of the curve Cb with respect to the integral value of the curve Cb is a value proportional to the apparent light amount difference between the scratch area 11a and the non-scratch area 11b, that is, the contrast. The integral value of each curve Ca, Cb is the sum of the amount of received light when the variable angle measurement operation is performed for each of the regions 11a, 11b, and can be obtained as the sum of the received light signal level. The scratch sensory value P is calculated.

  The scratch sensory value P calculated in this way can obtain a result that substantially matches the visual result as shown in FIG. In FIG. 8, in order to compare the scratch sensory value calculated by the measuring apparatus 10 with the visually scratch sensory value, the scratch sensory value P is multiplied by an appropriate coefficient. In addition, as the scratch sensory value is smaller, it means that scratches are less noticeable and scratch resistance is higher.

  The antiglare ratio calculation unit 23 d calculates an antiglare ratio indicating the antiglare property of the sample 11. The antiglare property can be evaluated by how far the parallel inspection light incident on the sample surface is diffused and reflected from the regular reflection angle. For this reason, as shown in FIG. 7, the half width of the curve Cb indicating the relationship between the light receiving direction angle θ2 of the non-scratched region 11b and the light intensity, that is, each light receiving whose light intensity is ½ of the peak value. When the width of the direction angle θ2 is θh, the antiglare ratio G is obtained by an antiglare ratio calculation formula “G = θh / 10 °”.

  Next, the operation of the above configuration will be described. When performing measurement, first, the scratch region 11a is formed in the sample 11, and the sample 11 is positioned by the sample frame 37 and placed on the stage 12, and then the exhaust pump is operated and fixed.

  After the sample 11 is fixed, the reference reflectance measurement sequence is started. When this sequence is started, the reference reflector 13 is set at the measurement position by the movement of the stage 12. Next, the angle adjuster 19 is driven by the drive motor 21 under the control of the control unit 22, and the light receiver 16 is rotated to a position where it receives the reflected inspection light that is regularly reflected. That is, the light receiver 16 is rotated to a rotation position where the light receiving direction angle θ2 is the same as the incident angle θ1.

  After rotating the light receiver 16 as described above, the inspection light converted into parallel light is irradiated from the projector 15 to the reference reflector 13 at the incident angle θ1, and the reflected inspection light that is regularly reflected on the surface of the reference reflector 13 is reflected. Light is received by the light receiver 16. Then, a light reception signal corresponding to the amount of the reflected inspection light received by the light receiver 16 is sent to the evaluation unit 23, the light reception signal level is held as the reference reflection light reception signal level, and the reference reflectance measurement sequence ends. .

  Following the reference reflectance measurement sequence, a first sub-sequence of the non-scratch region measurement sequence is started. In the first sub-sequence, the first measurement of the non-scratched region 11b of the sample 11 is moved to the measurement position by moving the stage 12 while maintaining the light receiver 16 at the rotation position where the light reception direction angle θ2 is the same as the incident angle θ1. A point is set. When the first measurement point is set, the collimated inspection light is irradiated from the projector 15 to the first measurement point, and the reflected inspection light specularly reflected at the first measurement point is received by the light receiver 16. . Then, the light receiving signal level obtained by performing the specular reflection light measurement operation on the first measurement point of the non-scratched region 11b in this way is held in the evaluation unit 23.

  When the specular reflected light measurement operation for the first measurement point in the non-scratched region 11b is completed, the stage 12 is moved again, and the second measurement point in the non-scratched region 11b at a position different from the first measurement point is at the measurement position. Set. Thereafter, the inspection light from the projector 15 is applied to the second measurement, the reflected inspection light is received by the light receiver 16, and the obtained light reception signal level is held in the evaluation unit 23. Thereafter, similarly, the stage 12 is moved to acquire and hold the received light signal levels of the third to fifteenth measurement points while changing the measurement points in the non-scratched region 11b.

  After obtaining the light reception signal level of the fifteenth measurement point, information on the measurement point corresponding to the light reception signal level in the middle (the eighth from the larger or smaller one) of the 15 light reception signal levels is represented by the evaluation unit 23. The measurement point information is sent to the control unit 22, and the first sub-sequence is completed and the second sub-sequence is started.

  When the control unit 22 receives the information on the representative measurement point, the control unit 22 moves the stage 12 so that the measurement point in the non-scratch region 11b, which is the representative measurement point based on the information, is set as the measurement position again, and the light receiving direction angle After the angle adjuster 19 is driven so that θ2 becomes the angle “θ1−Δθ”, the angle change measurement operation is started.

  First, at “θ1−Δθ”, the inspection light is irradiated to the representative measurement point to receive the reflected inspection light, and the light reception signal level at that time is acquired and held by the evaluation unit 23. Next, the light receiver 16 is rotated to a position where the light receiving direction angle θ2 is increased by 0.2 °, and the received light signal level at which the reflection inspection light is received at this position is acquired and held. Thereafter, similarly, the light receiving direction angle θ2 is sequentially increased in increments of 0.2 ° to “θ1 + Δθ”, and the received light signal level at which the reflection inspection light obtained at each angle is received is acquired and held.

  By acquiring the light reception signal level obtained by setting the light receiving direction angle θ2 to “θ1 + Δθ”, the second sub-sequence of the non-scratch region measurement sequence is completed, the non-scratch region measurement sequence is completed, and the scratch region measurement sequence is Be started.

  The first and second subsequences of the scratch area measurement sequence are different from the non-scratch area measurement sequence in that the measurement point is set within the scratch area 11a, but the first and second subsequences of the non-scratch area measurement sequence are different. It is done in the same way as Kens. Accordingly, a representative measurement point is determined from within the scratch area 11a by the first sub-sequence, and the light receiving direction angle θ2 is changed in steps of 0.2 ° from “θ1−Δθ” to “θ1 + Δθ” for the representative measurement point. Each received light signal level is acquired and held by the evaluation unit 23.

  When the scratch region measurement sequence is completed as described above, the reference reflected light reception signal level acquired in the first reference reflectance measurement sequence and the non-scratch region acquired in the first subsequence of the non-scratch region measurement sequence The evaluation unit 23 calculates the reflectance Rm of the sample 11 by applying the light reception signal level of the representative measurement point 11b and the reflectance Rs of the reference reflector 13 set in advance to the reflectance calculation formula. The sum of the received light signal levels obtained in the second sub-sequence of the scratch region measurement sequence is S1, and the sum of the received light signal levels obtained in the second sub-sequence of the non-scratch region measurement sequence is S2. The scratch sensory value P is determined by the evaluation unit 23 using the sensory value calculation formula.

  Furthermore, a peak value is extracted from each received light signal level obtained in the second sub-sequence of the non-scratch area measurement sequence, and the width of each received light direction angle θ2 that is ½ of the peak value is set to θh. The anti-glare ratio G is determined by the sex ratio calculation formula. Since each light receiving direction angle θ2 that is ½ of the peak value is not necessarily measured, θh may be calculated by performing interpolation using each light receiving signal level.

  It should be noted that the measurement results obtained by performing the variable angle measurement operation on the respective measurement points in the non-scratched area and the scratch area are respectively held, and the measurement points having the same light receiving direction angle θ2 as the incident angle θ1 are measured. A representative measurement point may be determined from the value, and the reflectance Rm, the scratch sensory value P, and the antiglare property ratio G may be obtained using the measurement result held for the representative measurement point. In this way, it is not necessary to set the measurement point on the sample 11 as the representative measurement point again at the measurement position, and the influence of the positional deviation due to the re-movement to the representative measurement point can be eliminated.

  9 and 10 show examples of actual measurement results. 9 and 10, as in FIG. 7, the relationship between the light receiving direction angle θ <b> 2 and the light intensity at the representative measurement point in the scratched area 11 a is a curve Ca, and the light receiving direction angle at the representative measurement point in the non-scratched area 11 b. θ2 and light intensity are indicated by a curve Cb.

  In the sample A shown in FIG. 9, the half-value width of the curve Cb for the non-scratched region 11b is as small as about 1 °. Therefore, the antiglare property G is small, and thus an evaluation result that the antiglare property is low was obtained. Moreover, in the sample B shown in FIG. 10, since the half width was as large as about 4 ° or more and the antiglare property G was increased, an evaluation result that the antiglare property was high was obtained. Furthermore, compared with the sample B, the sample A was evaluated to have a larger difference between the integrated values of the curve Ca and the curve Cb and lower scratch resistance. These were almost consistent with the actual visual results.

  In the above embodiment, the measurement is performed using parallel light. However, when measuring the scratch resistance, the diffused light may be irradiated. In addition, since it is the same as that of the said embodiment except being demonstrated below, the same code | symbol is attached | subjected to the same structural member and the description is abbreviate | omitted.

  As shown in FIG. 11, the projector 41 is provided with a diffusion plate 42 that diffuses light from a light source (not shown). An opening 43 is provided at the sample-side end portion of the projector 41, and the inspection light that is diffused by the diffusion plate 42 is irradiated toward the sample 11 from the opening 43. The opening 43 is circular with a diameter of 6 mm, and the opening angle θ3 facing the opening from the sample 11 (measurement position) is about 7 °. In addition, although the diameter of the opening 43 etc. can be set suitably, since measurement capability will fall when opening angle (theta) 3 is larger than 7 degrees, it is preferable to set it as 7 degrees or less. In addition, you may comprise so that the adapter which diffuses test | inspection light in this way and converts it into diffused light can be attached or detached to the light projector which irradiates the test | inspection light of parallel light.

  This projector 41 is used to measure the scratch resistance when the scratch region 11a is formed on the sample 11 using steel wool. That is, when the scratch resistance is measured for the sample 11 in which the scratch area 11a is formed using steel wool, the light is diffused by the projector 41 for each of the scratch area 11a and the non-scratch area 11b using diffused light. Irradiate the inspection light and perform an angle change measurement operation.

  When the scratch region 11a is formed on the sample 11 using steel wool, the scratch is formed in a deep groove shape, and thus the inspection light is reflected on the surface of the groove. For this reason, for example, when the light receiving unit 16 receives regular reflected light from the sample 11 in a state in which parallel light is irradiated as inspection light, the amount of received light varies greatly in the scratched region 11a, and the light in the non-scratched region 11b. It may be smaller or larger than the amount of light received. However, when diffused light is used as the inspection light as described above, the amount of light received in the scratch region 11a can always be greater than the amount of light received in the non-scratch region 11b, and scratch resistance is measured. Can do.

 In each of the above embodiments, each of the antireflection performance, the antiglare performance, and the scratch resistance is measured and evaluated. However, some of these are measured so that only one or a combination of the two is measured. Functions, sequences, and measurement operations can be omitted. Therefore, for example, a measuring device that measures anti-glare performance or scratch resistance can be used.

1 is a schematic front view including a block diagram showing a configuration of a measuring apparatus embodying the present invention. It is sectional drawing which shows the layer structure of the film as a sample. It is a schematic sectional drawing which shows the structure of a light projector. It is general | schematic sectional drawing which shows the structure of a light receiver. It is a top view which shows the state which set the sample on the stage. It is a functional block diagram which shows an evaluation part. It is a graph which shows the relationship of the light intensity of the injection | emission direction angle of a scratch part and a non-scratch part. It is a graph which shows a response | compatibility with the abrasion sensory value obtained with a measuring apparatus, and the visual sensory value by visual observation. It is a graph which shows the measurement result of a sample with low anti-glare property. It is a graph which shows the measurement result of a sample with high anti-glare property. It is a general | schematic fragmentary sectional view which shows the example which irradiated the diffused light to the sample.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Measuring apparatus 11 Sample 12 Stage 13 Reference | standard reflector 14 Stage moving mechanism 15 Light projector 16 Light receiver 19 Angle adjuster 23 Evaluation part

Claims (10)

A stage for holding the sample flat;
Moving means for moving an arbitrary part of the sample held on the stage to a measurement position by moving the stage;
A projector that has a light-projecting side optical system that collimates inspection light from a light source, and irradiates the surface of the sample placed at the measurement position with a predetermined incident angle from the light-projecting side optical system When,
It has a light receiving side optical system that extracts the light component parallel to the optical axis of the light incident from the optical axis direction, receives the light extracted by this light receiving side optical system, and receives a light receiving signal according to the amount of light received And a light receiver provided so that the optical axis of the light receiving side optical system passes through the measurement position and is rotatable in the incident surface around the measurement position.
Rotation means for rotating the light receiver in a predetermined angle range across a rotation position for receiving the regular reflection light of the inspection light;
The total amount of light received when the light receiver is rotated in the predetermined angle range by the rotating means with respect to the scratch area, and the light receiver within the predetermined angle range by the rotating means with respect to the non-scratched area. A first calculating means for calculating a total sum of received light amounts when rotated based on a received light signal from the light receiver, and calculating a numerical value indicating scratch resistance of the sample surface from each total received light amount;
Based on the light reception signal when the light receiver is rotated in the predetermined angle range with respect to the non-scratched region of the sample, the angle width of the light receiver that is half the peak value of the amount of light received is obtained, and from this angle width An optical performance measuring apparatus comprising: a second calculating unit that obtains a value related to antiglare property of a sample to be measured.   The moving means is configured such that a reference reflecting plate having a known reflectivity provided on the stage can be moved to a measurement position, and the reference reflector is in a state where the light receiver is in a rotation position in the regular reflection direction of inspection light. 2. The optical performance measurement according to claim 1, further comprising third calculation means for determining the reflectance of the sample from the signal level of each received light signal in the non-scratched area and the reflectance of the reference reflector. apparatus.   3. The optical performance measuring apparatus according to claim 1, wherein the light projecting side optical system and the light receiving side optical system are telecentric optical systems.   The optical performance measuring device according to claim 1, wherein the projector has a diffusing plate that uses inspection light as diffused light. A projector that irradiates the surface of the sample placed at the measurement position with a parallel inspection light at the light projection side optical system at a predetermined incident angle, and a light parallel to the optical axis of the light incident from the optical axis direction. It has a light receiving side optical system that extracts light components, receives light extracted by this light receiving side optical system, outputs a light receiving signal according to the amount of light received, and the optical axis of the light receiving side optical system indicates the measurement position. And using a light receiver that is rotatable in the incident surface around the measurement position,
While irradiating the measurement point in the scratch area formed on the sample with the inspection light, the light receiver is rotated within a predetermined angle range sandwiching the rotation position for receiving the specularly reflected light of the inspection light. A first variable angle measurement step for measuring the amount of light received at each angle in the angle range based on the received light signal;
The light receiver is rotated within the predetermined angular range while irradiating the measurement point in the non-scratched area of the sample, and the amount of light received at each angle in the predetermined angular range is measured based on the received light signal. 2 variable angle measurement steps;
Scratch resistance for obtaining a numerical value indicating the scratch resistance of the sample based on the sum of the respective received light amounts obtained in the first variable angle measurement step and the total of the received light amounts obtained in the second variable angle measurement step. A calculation step;
Based on the received light amount obtained in the second variable angle measurement step, the angular width of the light receiver that is half the peak value of the received light amount is obtained, and the value relating to the antiglare property of the sample to be measured is obtained from this angular width. An anti-glare resistance calculating step for obtaining an optical performance measuring method. With respect to “2n + 1” (n = 1, 2,...) Measurement points in the scratched area, the amount of received light is measured when the light receiver is in a rotational position for receiving the regular reflection light of the inspection light. The first specularly reflected light measuring step and the rotational position where the light receiver receives the specularly reflected light of the inspection light for “2m + 1” (m = 1, 2,...) Measuring points in the non-scratched region. A second regular reflection light measurement step for measuring the amount of received light when
Among the received light amounts obtained in the first specular reflection light measurement step, the measurement point that is the “n + 1” th received light amount is set as the measurement point in the first variable angle measurement step, and the second regular reflection light is obtained. 6. The optical performance according to claim 5, wherein a measurement point that is the “m + 1” th received light amount among the received light amounts obtained in the measurement step is set as a measurement point in the second variable angle measurement step. Measuring method. A reference reflection measurement step of measuring a received light amount when a reference reflector having a known reflectance is arranged at a measurement position and the light receiver is in a rotation position for receiving the regular reflection light of the inspection light;
Each signal level of the received light signal at the measurement point that is the received light amount of the “n + 1” th size among the received light amount obtained in the reference reflection measuring step and the received light amount obtained in the first specular reflected light measuring step. The optical performance measurement method according to claim 6, further comprising a reflectance calculation step of calculating a reflectance of the sample from the reflectance of the reference reflector.   8. The optical performance measuring method according to claim 5, wherein the scratch region is formed by rubbing steel wool or plastic eraser on the sample surface.   The optical performance measuring method according to claim 5, wherein the light projecting side optical system and the light receiving side optical system are telecentric optical systems.   For a sample having a scratch area formed by rubbing steel wool on the surface of the sample, a projector that irradiates diffused light is used instead of a projector that irradiates parallel light as inspection light during the first and second deflection measurement steps. The optical performance measuring method according to claim 5, wherein the optical performance measuring method is used.

Images