JP6450564B2 - Specimen for optical property measurement and optical property measurement method - Google Patents

Description

  The present invention relates to a resin-made specimen that is a sample for measuring optical characteristics, and an optical characteristics measuring method using the same, and in particular, an optical characteristics measuring specimen having a shape suitable for measuring optical characteristics and an optical characteristics measuring method. About.

In general, a colorless and transparent or colored transparent (including translucent) resin is used as an optical material in an illumination device such as an LED or a lamp.
For example, it is arranged around the headlight of a car and emits light in a ring shape, or covers light fixtures such as fluorescent lamps and light bulbs to make the light emission mode uniform, or planar light emission on the back of a liquid crystal display device provided in a smartphone etc. It is arranged as a body (backlight light guide plate) and used for the purpose of assisting the diffusion and propagation of light, such as uniformly irradiating a liquid crystal display device.

  Although such a resin exhibits its optical effect only after it is molded into a shape suitable for each application, by measuring the optical properties of the resin itself before molding into such a shape, The optical effect can be predicted (for example, Patent Document 1).

JP 2001-194302 A

In recent years, as a characteristic of a resin material required for such optical use, there is a tendency that a material having a high light transmittance and a low specific wavelength light absorptivity is preferred.
As an example of the optical characteristics of a resin having such characteristics, in order to measure the light transmittance, a specimen in which a resin material is molded into a predetermined shape is produced, and incident light incident from the end of the specimen is produced. It is necessary to measure the attenuation rate when the light is propagated through the resin material and emitted, and in order to measure the absorption rate of light of a specific wavelength, the incident light incident from the end of the subject propagates through the material. Therefore, it is necessary to measure the color difference when the light is emitted.

However, in the case of a material that originally has a high light transmittance and a low specific wavelength light absorptivity, a long optical path length is required until the light that has propagated through the subject is attenuated or until light of a specific wavelength is absorbed. If the total length of the subject itself is short, the difference in intensity between the incident light and the emitted light does not appear clearly.Therefore, when calculating the attenuation rate and absorption rate per unit length, measurement errors Will occur.
Therefore, it is conceivable to set the total length of the subject to a desired length. However, when the length is, for example, about 1 to 2 meters in terms of a linear distance, the handling of the subject becomes a problem. Therefore, it is difficult to produce a mold for molding a simple specimen, and as a result, it is difficult to measure optical characteristics.

  The present invention has been proposed in order to solve the above-described problems, and uses an optical characteristic measurement specimen capable of ensuring a desired optical path length while having a compact shape, and the specimen. An object is to provide a method for measuring optical characteristics.

  In order to achieve the above object, an object for measuring optical characteristics according to the present invention includes an incident part where light is incident, an emitting part from which incident light is emitted, and a guide for guiding light incident from the incident part to the emitting part. An optical portion, and the light guide portion has an optical path with a curvature that totally reflects incident light.

  The optical property measurement method of the present invention includes a step of causing light to enter a subject formed of a resin material, and a step of measuring light emitted through the subject, The subject includes an incident portion where light enters, an exit portion from which incident light exits, and a light guide portion that guides light incident from the incident portion to the exit portion, wherein the light guide portion is incident This is a method having an optical path with a curvature at which the reflected light is totally reflected.

  According to the optical characteristic measurement specimen of the present invention and the optical characteristic measurement method using the specimen, the optical path length of a desired length can be ensured despite the compact shape, so that the optical characteristics of the resin material can be accurately determined. Can be measured.

It is the schematic of the test object for an optical characteristic measurement which concerns on one Embodiment of this invention, (a) is a front view, (b) is a side view, (c) is a back view. It is explanatory drawing for demonstrating the light guide principle in a spiral optical path, (a) shows the object for optical characteristic measurement of this embodiment, (b) is a figure which shows the object for other optical characteristic measurement. . It is a figure which shows the structure of an output part, (a) is a perspective view of the reflector without the front-end | tip R formed in the triangular prism shape, (b) is a perspective view of the reflector with the front-end | tip R formed in the triangular prism shape, (c) ) Is a cross-sectional view of the emitting portion along the optical path length direction. It is a graph which shows the distance from the incident part of each output part. It is a figure for demonstrating the influence which the difference in optical path cross-sectional shape has on the propagation direction of light, (a) is a trapezoidal-shaped optical path cross-sectional view, (b) is a rectangular-shaped optical path cross-sectional view. It is a perspective view of the reflector formed in the semi-cylindrical shape, (a) shows a form in which the reflector is arranged without a gap, and (b) shows a form in which the reflector is arranged with a gap. It is the schematic of the reflector formed in hemisphere, (a) is a perspective view, (b) is a front view. It is explanatory drawing of the optical characteristic measuring method. It is a back view of the optical characteristic measurement object from which the connection angle of an incident part and a gate each differ, (a) is a connection angle of 90 degrees, (b) is a connection angle of 45 degrees, (c) is a connection angle of 30 degrees. FIG. It is a graph which shows the relationship between an optical path length and an emitted light intensity in the case where an output part is provided continuously over the optical path length and when it is provided intermittently, and (a) shows the relationship between the optical path length and relative luminance. (B) is a graph which shows the relationship between optical path length and the optical energy which passes an optical path cross section. (A) is a graph which shows the influence which the difference in the front-end | tip shape of a triangular prismatic reflector has on a luminance ratio (ratio when the brightness | luminance of distance 20cm is set to 100), (b) is the influence which the difference in optical path cross-sectional shape has on luminance. It is a graph which shows. It is a graph which shows the relationship between optical path length and outgoing light intensity according to reflector shape, (a) is a graph which shows the influence which the difference in reflector shape has on outgoing light intensity, and (b) is the difference in reflector shape is emitted. It is a graph which shows the influence which acts on the intensity according to angle.

  Hereinafter, preferred embodiments of an object for measuring optical properties and an optical property measuring method according to the present invention will be described with reference to the drawings.

[Optical property measurement specimen]
The optical property measurement subject 1 of the present embodiment is a resin subject for measuring the optical properties of a predetermined resin material. As shown in FIG. The light emitting section 20 from which the emitted light is emitted and the light guide section 30 that guides the light incident from the incident section 10 to the light emitting section 20 are provided.

The resin material is a synthetic resin to be a measurement sample, and can be a preferable specimen for measuring optical characteristics of the synthetic resin by molding into a shape as shown in FIG. 1 by injection molding.
As the resin material, various synthetic resins such as acrylic resin, polycarbonate, styrene resin, cyclopolyolefin, and vinyl chloride resin can be used, as long as they have translucency enough to transmit light. The material is not particularly limited.

The incident part 10 is a start end face provided at a position away from the center of the light guide part 30, and a light source having a predetermined wavelength region is disposed in the vicinity thereof, whereby light from the light source is guided from the start end face. The light enters the portion 30.
A gate 40 is provided from the incident part 10 to the center of the light guide part 30. At the time of injection molding, the molten resin material is filled into the mold through the gate 40, and the optical property measuring specimen 1 is molded.

The light guide unit 30 has an optical path 301 that guides incident light to the output unit 20 in order to propagate the incident light from the input unit 10 into the light guide unit 30 and output the light from the output unit 20.
The optical path 301 is formed in a spiral shape, and is configured such that the curvature continuously changes from the incident part 10 serving as the optical path start end surface to the terminal end part 50.
The radius of curvature R ₀ (outer radius) of the incident portion 10 serving as the starting point of the optical path 301 is 40 mm or more, preferably 53 mm or more, and the gap S between the optical paths 301 is 5 to 10 mm, preferably 6 mm.
The optical path width W ₀ of the optical path 301 is 5 to 15 mm, preferably 10 mm, and the height h ₀ of the optical path 301 is 1 to 5 mm, preferably 2.5 mm.
By forming the optical path 301 in a spiral shape in this way, the optical property measuring subject 1 can be formed more compactly than when the optical path is linear.

例えば、臨界角θｃが３９．１°のポリカーボネートと空気では、Ｗ_０が１０ｍｍの場合はＲ_０が２７．１ｍｍ以上、Ｗ_０が１５ｍｍの場合はＲ_０が４０．６ｍｍ以上となる。 Such preferable radius of curvature R ₀ and optical path width W ₀ can be obtained from the light guiding principle as shown in FIG.
FIG. 2 is a diagram illustrating the characteristics of the light L propagating in the optical path 301, where θi represents an incident angle and θc represents a critical angle.
The light L is totally reflected at the interface between substances having different propagation speeds (in this case, resin and air layer) when the incident angle θi is larger than the critical angle θc, and the incident angle θi is larger than the critical angle θc. When it is small, it is known that light is emitted from the boundary surface with a predetermined emission angle.
For example, when the resin material is polycarbonate, since the critical angle θc from the polycarbonate to the air is about 39.1 °, total reflection occurs at an incident angle θi ≧ 39.1 °, and the incident angle θi <39.1 °. Then, it will radiate | emit to air from a polycarbonate.
In order to guide the incident light from the incident part 10 to the emission part 20 while suppressing the attenuation as much as possible, the light needs to propagate while repeating total reflection at the boundary surface. For this purpose, the incident angle θi is a critical angle. The optical path 301 must be formed so as to be always larger than θc.
However, since the optical path 301 is formed in a spiral shape, as shown in FIG. 2B, when the radius of curvature is small, the incident angle θi may be smaller than the critical angle θc. In such a case, the light L is not totally reflected and is emitted out of the optical path 301 with a predetermined emission angle, so that a sufficient amount of light L cannot be guided to the emission unit 20.
At this time, not only the radius of curvature but also the optical path width W ₀ is a factor that attenuates light. If the optical path width W ₀ is larger than a predetermined value, the propagation angle of the light L is widened. Thus, the incident angle θi may be smaller than the critical angle θc at the boundary surface.
Therefore, the subject for optical property measurement 1 of the present invention defines the radius of curvature R ₀ and the optical path width W ₀ to the above values while forming the optical path 301 in a spiral shape. The incident light is propagated to the emitting portion 20 while repeating total reflection. Further, the reason why only the radius of curvature of the incident portion 10 that is the starting point is defined is that the radius of curvature continuously increases as light advances from the incident portion 10, which acts in a direction that promotes total reflection. This is because it is necessary and sufficient if only the radius of curvature of the incident portion 10 corresponding to the portion having the smallest radius is defined.
As described above, in order to totally reflect most of the incident light and guide a sufficient amount of light to the emitting unit 20, the radius of curvature _R0 of the incident unit 10 is larger than the value obtained by the following Equation 1. It is necessary to take.

For example, the polycarbonate and air the critical angle θc is 39.1 °, if _{W 0} is 10 mm _{R 0} is more 27.1Mm, if _{W 0} is 15 mm _{R 0} is equal to or greater than 40.6 mm.

The emitting unit 20 is a part having a function of emitting the light incident from the incident unit 10 and propagating through the optical path 301 to the outside of the subject by controlling the propagation direction. In the present embodiment, the emitting unit 20 The structure made to radiate | emit from the surface 1a orthogonal to the incident part 10 which becomes.
In order to realize such a configuration, a reflector 20a is provided on the back surface 1b. In the present embodiment, the reflector 20a is formed so as to protrude outward from the back surface 1b. In the example shown in FIG. 3, a plurality of triangular prisms are arranged side by side so that their longitudinal directions are orthogonal to the optical path length direction. It is.
With such a configuration, as shown in FIG. 3C, the light L propagating in the optical path 301 is reflected by the inclined surface of the triangular prism and is emitted from the back surface 1b side toward the front surface 1a side. .
Side reflector 20a such triangular prism type, width _{W 1} is 4 mm, the height _{h 1} is 0.5 mm, the pitch _{P 1} is 0.5 mm, the inclination angle alpha ₁ is 45 °, the arrangement number is preferably 10.
It is also possible to narrow triangular prism while maintaining a scale other than the width W _1, in which case, by increasing the arrangement number to maintain the length of the optical path length direction. The length T ₁ of the reflector region in the optical path length direction is determined by the product of the pitch P ₁ and the number of arrangement (T ₁ = P ₁ × number of arrangement). The number of arrangement | positioning is required at least 2 pieces, and 5 or more are preferable. The area of the reflector (W ₁ × T ₁ ) is preferably as small as possible in consideration of the attenuation of incident light. On the other hand, cameras, luminance meters, and illuminance meters (hereinafter referred to as “light emitting devices”) that receive emitted light. It is preferably larger than the measurement diameter of the light receiving device (abbreviated as camera).
The inclination angle α ₁ is a factor that affects the emission direction of the light L, and can be appropriately changed according to the position of a light receiving device such as a camera. In the present embodiment, (see FIG. 8) to be placed in a vertical (perpendicular) direction with respect to the camera surface 1a, the inclination angle alpha ₁ is preferably 45 °. Thereby, most of the emitted light can be directed in a direction perpendicular to the surface 1a.
Further, the number of arrangement is a factor that affects the increase / decrease in the amount of light, and can be appropriately changed according to the number and interval of the emission units 20.

  Moreover, in the triangular prism type reflector 20a, it is preferable that the shape of the tip is a sharp shape without chamfering such as an R shape. This is because if the tip has an R shape, the light whose reflection direction is not fixed increases, and the light traveling in the direction perpendicular to the surface 1a decreases (see FIG. 11A).

A plurality of such reflectors 20a are provided on the optical path 301, and each reflector 20a emits light propagating in the optical path 301 to the outside of the subject by controlling the propagation direction thereof. Yes.
In the present embodiment, eight reflectors 201 a to 208 a are provided on the optical path 301, and the optical property measurement subject 1 includes eight emission units 201 to 208 according to this.
The number of such emitting portions 20 (reflectors 20a) is not particularly limited and can be appropriately selected. However, it is preferable that the arrangement thereof has a certain law.
For example, in this embodiment, as shown to Fig.1 (a), each output part 201-208 is arrange | positioned so that it may be located on the one straight line k in front view.
With this arrangement, when the light emitted from each light emitting unit 20 is received by a light receiving device such as a camera, the light receiving element, the lens, the light receiving device itself, and the like included in the light receiving device are scanned along a straight line k. Therefore, the scanning time is shortened and the measurement speed is increased.

In order to realize such a law property, as shown in FIG. 4, the emission parts 201 to 208 are arranged with a specific distance from the incident part 10, and have different optical path lengths from the incident part 10. ing.
Each of the reflectors 20a may have a different shape, but preferably has the same shape. This is because the intensity of the emitted light also changes when the shape is different, so that the optical path length is an optical characteristic. This is because it is preferable to eliminate other influences as much as possible in order to confirm the influence on (for example, attenuation rate, color difference, etc.).

Thus, in this embodiment, since it is comprised so that light may be radiate | emitted from the surface 1a orthogonal to the incident part 10 (start end surface), the light L which propagates the inside of the optical path 301 is provided in the back surface 1b. It is necessary to control so as to be directed toward the reflector 20a.
Therefore, the optical path 301 has the following characteristic cross-sectional shape.

Each (i) of FIG. 5 is a cross-sectional view taken along line AA shown in FIG. 1 (a), each (ii) of FIG. 5 is a cross-sectional view taken along line BB shown in FIG. 1 (a), and FIG. ) Shows a preferred embodiment of the present invention, and FIG. 5B shows another embodiment.
When the cross-sectional shape of the optical path 301 that is orthogonal to the optical path length direction is formed in a rectangular shape as shown in FIG. 5B (i), the light travels parallel to the front surface 1a and the back surface 1b. Since the optical path 301 has a curvature, L propagates through the optical path 301 while being reflected by the boundary surface (both side faces) in the optical path width W ₀ direction as shown in FIG. 5B. interface height h ₀ direction, i.e., not be incident on the surface 1a and the back surface 1b. That is, when the cross-sectional shape is rectangular, the light L traveling parallel to the front surface 1a and the back surface 1b does not actively travel toward the reflector 20a provided on the back surface 1b.
On the other hand, in this embodiment, the shape of the cross section orthogonal to the optical path length direction is formed in a trapezoidal shape as shown in (i) of FIG. In this way, even the light L traveling parallel to the surface 1a and the back surface 1b, when incident on the trapezoidal hypotenuse, the propagation direction is changed according to the inclination angle alpha ₂ of the oblique side, in FIGS. 5 (a) as shown, so that the the optical path height h ₀ direction to obtain the deflection angle can be propagated. Thereby, the light L traveling parallel to the front surface 1a and the back surface 1b can be actively directed to the reflector 20a provided on the back surface 1b.
Inclination angle alpha ₂ required for control of such propagation direction is 2 ° to 30 °, preferably, 4 ° to 10 °.

Further, in the present embodiment, for the purpose of aligning the directivity of the light L propagating in the optical path 301, the escape emitting part 200 for positively escaping a part of the incident light to the outside of the optical path 301 is provided. The escape emitting part 200 is disposed at a position closer to the incident part 10 than the other emitting parts 20 (see FIGS. 1 and 4), and, like the other emitting parts 20, the escape reflector 200a is provided on the back surface 1b. doing.
By providing the escape emitting part 200 as described above, among the light incident from the incident part 10, light having a deflection angle in the direction of the optical path height h ₀ is positively emitted out of the optical path 301, and directivity The light L having the same value propagates through the optical path 301. Thereby, a disturbance factor is suppressed and the accuracy of measurement can be improved.
Incidentally, side reflector 200a for relief, which may be the same shape as the other side reflector 20a, the arrangement number of the triangular, for example, by more than the other side reflector 20a, deflection of the optical path height h ₀ direction It is preferable to adopt a shape that positively emits light having an angle out of the optical path 301.

Moreover, although the shape of the reflector 20a including the escape reflector 200a is preferably a triangular prism type, a reflector 20a having another form can also be adopted.
For example, a semi-cylindrical reflector 20a as shown in FIG. 6 can be adopted, and a hemispherical reflector 20a as shown in FIG. 7 can also be adopted.

In the semi-cylinder type reflector 20a, as shown in FIG. 6A, the semi-cylinder can be arranged without a gap (half-cylinder A type), but as shown in FIG. (Semi-cylinder B type).
In either type, the width _{W 2} is 4 mm, the height _{h 2} is 73Myuemu, pitch _{P 2} is 352μm is preferable. The number of arrangement is preferably 14 in the example shown in FIG. 6A and 10 in the type shown in FIG. 6B. Further, the clearance _{S 2} is 0.5mm is preferred.
It is also possible to narrow semicylindrical while maintaining the scale of the non width W _2, in which case, by increasing the arrangement number to maintain the length of the optical path length direction. The height h ₂ and the pitch P ₂ are preferably about 1: 5.
Among such semi-cylindrical reflectors 20a, the amount of light emitted from the surface 1a is greater in the semi-cylinder A type in which the semi-cylinders are arranged without gaps than in the semi-cylinder B type in which the gaps are arranged. Tend to increase (see FIG. 12).
Further, when such a semi-cylindrical type reflector 20a and a triangular prism type reflector 20a are compared, there is no significant difference in the amount of light emitted from the surface 1a (see FIG. 12).

In the hemispherical type reflector 20a, the diameter D is 352 μm, the pitch P ₃ is the diameter D to 1 mm, the pitch P ₄ is the diameter D to 1 mm, and the height h ₃ is within the range of length T ₃ × width W _3. 73 μm is preferable.
It is also possible to reduce the hemisphere while maintaining a scale other than length T ₃ × width W ₃ , in which case the number of arrangements is increased to maintain length T ₃ × width W ₃ . It is preferable that the height h ₃ and the diameter D are approximately 1: 5.
Such hemispherical type reflectors 20a tend to have a smaller amount of light emitted from the surface 1a than the triangular prism type and semicylindrical type reflectors 20a (see FIG. 12).

[Optical characteristics measurement method]
A method for measuring the optical properties of the synthetic resin constituting the subject using the optical property measuring subject 1 configured as described above will be described.
The optical property measuring object 1 is placed on a predetermined installation table 300. At this time, it mounts so that the back surface 1b side may face the installation base 300. Note that the installation table 300 preferably has a color that easily absorbs light such as black.
Subsequently, a light source having a predetermined wavelength region is disposed in the vicinity of the incident portion 10 illustrated in FIG. 1A, and light from the light source is irradiated toward the incident portion 10.
Light from the light source enters the light guide unit 30 from the incident unit 10 serving as the optical path start end surface, and propagates toward the terminal unit 50 while repeating total reflection along the optical path 301.

When the incident light reaches the relief for emitting portion 200, where emitted out of the optical path 301 light actively with deflection angle of the optical path height h ₀ direction, thereafter, the light L having uniform directional It propagates in the optical path 301. Furthermore, when it advances, it reaches | attains the output part 201 which is the output part 20 with the shortest optical path length.
Here, the light traveling in the direction of the reflector 201a is reflected on the inclined surface of 45 ° and emitted in a direction perpendicular to the surface 1a.
The light that has passed through without being emitted from the emission unit 201 reaches the next emission unit 202 although the amount of emitted light is relatively reduced. Here, similarly, the light traveling in the direction of the reflector 202a is reflected by the inclined surface and emitted in a direction perpendicular to the surface 1a.
Thereafter, the above-described emission is repeated also in each of the emission units 203 to 208, and the light that has escaped the emission is emitted from the termination unit 50.
On the other hand, the light emitted from each of the emission units 201 to 208 is received by the camera 100 having the light receiving surface in the vertical direction with respect to the surface 1a.
Since each emission part 201-208 is arrange | positioned on the straight line k, by moving the camera 100 along the straight line k, the intensity | strength and wavelength distribution of the light radiate | emitted from each emission part 201-208, for example. Etc. can be measured.
Then, by comparing (for example, calculating the ratio) the intensity and wavelength distribution of the light source and the intensity and wavelength distribution of the light emitted from each of the emission units 201 to 208, the optical properties of the synthetic resin that constitutes the subject. Characteristics (for example, attenuation rate, absorption rate of a specific wavelength) can be obtained.
By obtaining such optical characteristics for a plurality of types of synthetic resins based on one synthetic resin, it is possible to relatively compare the characteristics of a plurality of synthetic resins on the assumption that the specimen is molded into the same shape. Become.

  As described above, according to the optical property measurement subject of this embodiment and the optical property measurement method using the subject, it is possible to secure an optical path length of a desired length while having a compact shape. Therefore, for example, it is possible to measure optical characteristics such as an attenuation rate and an absorption rate at a specific wavelength.

  The preferred embodiments of the optical property measurement subject and optical property measurement method of the present invention have been described above. However, the optical property measurement subject and optical property measurement method according to the present invention are limited to the above-described embodiments. Needless to say, various modifications can be made within the scope of the present invention.

For example, in the present embodiment, the reflector 20a is formed to be convex on the back surface 1b, but may be formed to be concave on the back surface 1b.
In the present embodiment, the cross-sectional shape orthogonal to the optical path length direction is a trapezoidal shape, but it is sufficient that the side surface has an inclination angle α ₂ on at least one side surface in the optical path width W ₀ direction. The shape may not be trapezoidal.

The angle at which the incident portion 10 and the gate 40 are connected is not particularly limited. For example, as shown in FIG. 9, the connection angle β is 90 ° in FIG. One of 30 ° and 30 ° in FIG. At this time, it is preferable to select the incident portion 10 having the connection angle β with the least light leakage.
Further, in the present embodiment, the escape emitting part 200 is provided, but instead of or in addition to this, a polarizing plate may be provided between the light source and the incident part 10. Thereby, light with uniform directivity can be incident on the incident portion 10.
In addition, the optical property measurement specimen of the present invention can also be used as a molded product of a spiral flow test for evaluating the flow characteristics during injection molding of a resin material. For example, in a molded product molded under a certain molding condition (resin temperature, injection pressure, etc.), the evaluation is such that the longer the length from the incident part 10 to the terminal part 50 (optical path length), the higher the fluidity of the resin. It can be performed.
In addition, for the terminal portion 50 of the subject formed by the spiral flow test, a cross section in a direction orthogonal to the incident light is formed in a flat shape, and the camera is installed on the same axis as the incident light. It is also possible to measure the light that has passed through.

Further, in order to explain the optical property measurement object and the optical property measurement method according to the present invention in more detail, the following measurement materials are disclosed.
For example, FIG. 10 shows the optical path length and the output light from the output part in an example in which the output part (reflector) is provided intermittently as in this embodiment and in an example in which the output part is provided continuously over the optical path length. It is a graph which shows the relationship with an intensity | strength, (a) is a graph which shows the relationship between optical path length and relative brightness, (b) is a graph which shows the relationship between optical path length and the optical energy which passes an optical path cross section.
As a result, in the example in which the emission part (reflector) is continuously provided over the optical path length, the intensity (luminance) of the light is extremely decreased with a certain optical path length as a boundary, but the example is provided intermittently. Then, since light is emitted only from the emitting part, it can be seen that the intensity (luminance) of the light gradually decreases for each emitting part provided for each predetermined optical path length without extremely decreasing. Moreover, in the example provided intermittently, it turns out that the emitted light from other than an emission part cannot be confirmed.

FIG. 11A is a graph showing the influence of the difference in tip shape on the luminance in a triangular prism type reflector. Looking at this, in the example of the tip R shape, the exit is relatively close to the incident portion 10. It can be seen that the sharp shape without the tip R is preferable because the luminance is lowered at the portion.
Further, FIG. 11 (b) are graphs difference in optical path cross section showing the effect on the brightness, see, than without the cross-sectional shape inclined angle alpha _2, a tilt angle alpha ₂ cross section ( In particular, the inclination angle α ₂ = 6 °, 10 °) has a higher luminance from the emission part, and thus it can be seen that the inclination angle α ₂ contributes to an increase in the amount of light toward the reflector 20a.

FIG. 12 is a graph showing the influence of the difference in reflector shape on the outgoing light intensity and outgoing angle, (a) is a graph showing the relationship between the optical path length and outgoing light intensity, and (b) is the outgoing angle. It is a graph which shows the emitted light intensity for every (90 degrees, 30 degrees).
From these, it can be said that the triangular prism type reflector is most excellent in the emitted light intensity in the 90 ° direction where the camera 100 is located.

  The present invention can be suitably used as a specimen and a measurement method when measuring optical characteristics of a resin material.

DESCRIPTION OF SYMBOLS 1 Optical characteristic measurement object 10 Incident part 20 Outer part 30 Light guide part 301 Optical path 20a Reflector 100 Camera 300 Installation stand

Claims (2)

An incident part where light is incident;
An emission part from which incident light is emitted; and
A light guide part that guides light incident from the incident part to the emission part,
The object for measuring optical characteristics, wherein the light guide section has an optical path with a curvature that totally reflects incident light. A step of causing light to enter a subject formed of a resin material;
Measuring the light propagated through the subject and emitted,
The subject is
An incident part where light is incident;
An emission part from which incident light is emitted; and
A light guide part that guides light incident from the incident part to the emission part,
The optical guide measuring method, wherein the light guide unit has a curvature optical path in which incident light is totally reflected.

Images