JP2001235370A - Device for measuring reflection property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost by simplifying the structure of a device. SOLUTION: A reference plate 5 is placed near a measuring opening 3 where a measuring sample 4 is mutually opposingly placed, and a sample beam reflected on the sample 4 and a reference beam reflected on the reference plate 5 are introduced into a first incident slit and a second incident slit of a masking plate 24, respectively, by an optical means consisting of a plain reflecting mirror 21 and image forming lenses 22, 23. Each of the sample beam and the reference beam passing through the first incident slit and the second incident slit, respectively, is spectroscopically divided by a spectroscopical part 30, and each electrical signal corresponding to light intensity of divided beam is outputted by a detecting part 40 every wavelength. The spectroscopic reflection property of the sample 4 is calculated by a processing part 50 using each electrical signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a spectrophotometer,
The present invention relates to a reflection characteristic measuring device for measuring a spectral reflection characteristic of a sample.

[0002]

2. Description of the Related Art Generally, the measurement of the reflection characteristics of a sample is greatly affected by the optical conditions (geometry) of an illumination system and a light receiving system. Therefore, many reflection characteristic measuring devices such as spectrophotometers are recommended by the CIE (International Commission on Illumination).
Optical conditions (geometry: 0 (45 ° illumination, vertical reception), 0/45 (vertical illumination, 45 ° reception), d / 0 (diffuse illumination, vertical reception), 0 / d (vertical illumination, diffusion reception) ) Is adopted.

[0003] In such a reflection characteristic measuring apparatus, generally, a result of measurement using a white calibration plate as a sample is stored as calibration data, and the reflection characteristic of the sample is calculated using the calibration data. I have. Here, if the emission intensity of the light source fluctuates between calibration and measurement, an error will occur in the measurement.Therefore, during calibration or measurement, a part of the light output from the light source is taken in as reference light, and When calculating the reflection characteristics based on the output value of the reflected sample light,
Correction is performed using the output value of the reference light so that no error occurs in the measured value even if the light emission intensity of the light source fluctuates. For example, Japanese Patent No. 2747915 discloses that a part of reflected light from an effective surface on a measurement surface is sent to an optical waveguide connected to a spectrometer, and a part of illumination light from a light source is transmitted by a reference optical waveguide. A measuring head having a configuration adapted to capture is described.

[0004]

However, in the measuring head described in the above-mentioned conventional Japanese Patent No. 2747915, illumination light from a light source is guided separately from an optical waveguide for guiding reflected light from a measuring surface to a spectrometer. Since it has a reference light waveguide,
There has been a problem that the device configuration becomes complicated and the cost increases accordingly.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem, and a reflection characteristic measuring apparatus which can simplify the apparatus configuration and reduce the cost by sharing the optical means for guiding the sample light to the spectroscopic means for guiding the reference light. The purpose is to provide.

[0006]

According to a first aspect of the present invention, there is provided a measurement opening in which a measurement sample is disposed to face, a reference plate disposed near the measurement opening, the measurement opening and the reference plate. Illuminating means for illuminating a range including, and illumination light from the illuminating means is arranged in a region where the sample light reflected by the measurement sample and the reference light reflected by the reference plate are guided, and the sample light and the A spectroscopic means for dispersing the reference light, a mask plate disposed on the incident light side of the spectroscopic means and having a first opening through which the sample light passes and a second opening through which the reference light passes; An optical unit that is disposed on the incident light side and guides the sample light and the reference light to the first opening and the second opening of the mask plate, respectively, and outputs an electric signal corresponding to the light intensity of the split sample light. For each wavelength Detecting means for outputting an electric signal corresponding to the light intensity of the dispersed reference light for each wavelength, and calculating a spectral reflection characteristic of the measurement sample using each electric signal output from the detecting means. Signal processing means.

[0007] According to this configuration, the reference plate is arranged near the measurement opening in which the measurement sample is opposed, and the area including the measurement opening and the reference plate is illuminated by the illumination means. The sample light reflected by the measurement sample and the reference light reflected by the reference plate are guided to the first opening and the second opening of the mask plate by the optical means, respectively. Each of the passed reference lights is split by the splitting means. Further, an electric signal corresponding to the light intensity of the separated sample light and an electric signal corresponding to the light intensity of the separated reference light are output for each wavelength by the detecting means, and each electric signal output from the detecting means is output. Is used to calculate the spectral reflection characteristics of the measurement sample.

As described above, the sample light reflected by the measurement sample and the reference light reflected by the reference plate are guided to the first opening and the second opening of the mask plate by the common optical means. Therefore, the device configuration is simplified.

According to a second aspect of the present invention, in the reflection characteristic measuring apparatus according to the first aspect, the measurement opening and the first opening are arranged at positions conjugate to each other with respect to the optical means, and The second opening is characterized in that it is arranged at a position substantially conjugate to each other with respect to the optical means.

According to this configuration, the measurement opening and the first
Since the apertures are arranged at positions conjugate to each other with respect to the optical means, the measurement range of the sample light is a range determined by the magnification of the optical means with respect to the first aperture in the range illuminated by the illumination means. Further, since the reference plate and the second aperture are arranged at positions substantially conjugate to each other with respect to the optical means, the measurement range of the reference light is determined by the magnification of the optical means with respect to the second aperture in the range illuminated by the illumination means. Range. Further, with such an arrangement, an image in the measurement range of the sample light and the reference light is suitably guided to the spectroscopic means.

According to a third aspect of the present invention, in the reflection characteristic measuring device according to the first or second aspect, the illuminating means comprises:
The above-mentioned range is illuminated from an angle inclined by 45 ° with respect to the normal line of the measurement opening, and the optical means is a component of the light reflected by the measurement sample along the normal line of the measurement opening. Is guided to the first opening.

According to this configuration, the above-described range is illuminated by the illuminating means from an angle inclined by 45 ° with respect to the normal line of the measurement opening, and the light reflected along the normal line of the measurement opening among the light reflected by the measurement sample. The guided component is guided to the first aperture by the optical means, so that a simple configuration is used and the component defined by the CIE is used.
° Illumination, vertical light receiving geometry device is realized.

According to a fourth aspect of the present invention, in the reflection characteristic measuring apparatus according to the third aspect, the reference plate is provided for measuring the reflection characteristic so that specular reflection light of illumination light from the illumination means is directed to the optical means. It is characterized by being arranged obliquely with respect to the opening surface of the opening.

According to this configuration, the reference plate is disposed inclined with respect to the opening surface of the measurement opening so that the specular reflection light of the illumination light from the illumination means is directed to the optical means. The light intensity of the reference light reflected by the light source increases. Therefore, the S / N of the electric signal corresponding to the light intensity of the reference light output from the detecting means increases, and the reproducibility of the measurement is improved.

According to a fifth aspect of the present invention, in the reflection characteristic measuring device according to the first or second aspect, the size of the second opening is larger than the size of the first opening.

According to this configuration, the size of the second opening is
Since the size is larger than the size of the first opening, the light intensity of the reference light reaching the detection means increases, and thereby the S / N of the electric signal corresponding to the light intensity of the reference light output from the detection means is increased.
Is increased, so that the reproducibility of the measurement is improved.
This configuration is particularly effective when the spectral luminance characteristic of the light source does not include a bright line.

According to a sixth aspect of the present invention, in the reflection characteristic measuring apparatus according to the first aspect, a red light absorbing infrared light having a wavelength in an infrared region is provided between the illumination means and the optical means and the measurement aperture. It is characterized in that an outer cut filter is provided.

According to this configuration, since the infrared cut filter is interposed between the illumination means and the optical means and the measurement aperture, light having a wavelength in the infrared region is not irradiated on the measurement sample. Therefore, even if the same measurement sample is repeatedly measured, a rise in the temperature of the measurement sample is suppressed, and a constant measurement accuracy is maintained.

According to a seventh aspect of the present invention, in the reflection characteristic measuring apparatus according to the sixth aspect, the measurement opening is closed by the infrared cut filter.

According to this configuration, the infrared cut filter prevents dust from entering the inside of the apparatus through the measurement opening, and a dustproof effect can be obtained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the configuration of a spectrophotometer as an embodiment of a reflection characteristic measuring apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of the spectrophotometer, and FIG. 2 is a plan view of the spectrophotometer. FIG. 3 is a front view of the limit frame, FIG. 4 is a front view of the mask plate, and FIG.
(B) is a partial plan view showing an illumination range and a measurement range. 6A and 6B are views showing a detection unit, FIG. 6A is a side view, and FIG.
Is a front view. FIG. 7 is a block diagram showing an electrical configuration of the spectrocolorimeter. Note that, for convenience of description, the light source, the detection unit, and the processing unit are not illustrated in FIG. 2, and the light source and the light receiving unit are not illustrated in FIG. 5.

As shown in FIG. 1, this spectrophotometer 1
An operation display unit 2 is provided on the upper surface, and a measurement opening 3 is provided on the bottom surface. The color of the measurement sample 4 is measured while the measurement opening 3 is in contact with the measurement sample 4. It includes a light receiving section 20, a spectroscopic section 30, a detecting section 40, a processing section 50, and the like.

The operation display unit 2 includes operation switches operated by a user, for example, a measurement switch for instructing the start of measurement, a calibration switch for instructing the start of calibration, and the like, and for displaying measurement results and the like. LCD
It has.

A reference plate 5 is provided near the measurement opening 3. The reference plate 5 is, for example, a plate painted white or light gray, and has an illumination unit 10 for calibration and measurement.
To compensate for the effects of variations in illumination light intensity from
This is for obtaining the light intensity of the illumination light, and reflects the illumination light from the illumination unit 10 toward the light receiving unit 20 without passing through the measurement sample 4. The reference plate 5 is arranged to be inclined with respect to the opening surface of the measurement opening 3 so that the regular reflection light of the illumination light from the illumination unit 10 goes to the light receiving unit 20. The reference plate 5 is not limited to a plate painted white or light gray. For example, a plate printed in white or light gray or a plate made of a white material such as ceramic may be used.

The illumination unit 10 includes a light source 11, a limit frame 12, a toroidal mirror 13, and an infrared cut filter 14,
This illuminates the area including the measurement opening 3 and the reference plate 5. The light source 11 is composed of a tungsten lamp having a short-dimension filament, and is arranged so that the filament coincides with the normal 3n of the measurement opening 3. The restriction frame 12 has an opening 12a, blocks light outside the desired illumination area, and prevents harmful light from entering the light receiving unit 20. The center of the restriction frame 12 is the normal 3n of the measurement opening 3. Are arranged to match. As shown in FIG. 3, the opening 12a has a C-shaped portion 12b and a fan-shaped portion 1 on the left side thereof.
2c.

The toroidal mirror 13 has an aspherical surface formed by rotating a curve around an axis. As shown in FIG. 2, the toroidal mirror 13 surrounds the measurement opening 3 except for the light receiving section 20. A C-shape in plan view is employed, and the inner surface is a mirror surface formed by vacuum-depositing a metal such as aluminum. This toroidal mirror 13 is
1 (in this embodiment, the position of the filament of the tungsten lamp) is arranged so that the focal point coincides therewith, and the light from the light source 11 reflected by the toroidal mirror 13 is made substantially parallel light. Instead of the toroidal mirror 13, a spherical mirror formed by rotating an arc around an axis may be used.

The infrared cut filter 14 is used for the measurement aperture 3.
, Which absorbs infrared wavelength component light and transmits wavelength components smaller than the infrared wavelength component. The infrared cut filter 14 closes the measurement opening 3.

The light receiving section 20 includes a plane reflecting mirror 21, image forming lenses 22, 23, a mask plate 24, and a field lens 2.
The illumination light from the illumination unit 10 guides the sample light reflected by the measurement sample 4 to the spectroscopy unit 30 and the reference light reflected by the reference plate 5 to the spectroscopy unit 30.

As shown in FIG. 4, the mask plate 24
It includes an entrance slit 241 and a second entrance slit 242, and includes an illumination range of illumination light from the illumination unit 10,
This is for limiting the measurement region guided to the spectroscopic unit 30 by the slits 241 and 242. First entrance slit 24
1 is drilled slightly above the center, the second entrance slit 242 is drilled below it, and the horizontal dimension of the slit in the drawing is the second dimension from the first entrance slit 241.
The entrance slit 242 is larger.

The first entrance slit 241 and the measurement aperture 3 are arranged at positions conjugate with each other with respect to the optical means comprising the plane reflecting mirror 21 and the imaging lenses 22 and 23, and
The entrance slit 242 and the reference plate 5 are arranged at positions substantially conjugate to each other with respect to the optical means including the plane reflecting mirror 21 and the imaging lenses 22 and 23.

As shown in FIG. 2, the field lens 25 is disposed slightly inclined with respect to the optical axis L1 of the imaging lenses 22 and 23, and the first and second entrance slits 241 and 241 of the mask plate 24. The light passing through 242 is guided as parallel light to the light splitting unit 30, and the light separated and reflected by the light splitting unit 30 is imaged on the detection unit 40 via the plane reflecting mirror 31.

Returning to FIG. 1, the spectroscopic unit 30 is arranged in the vertical direction (FIG. 2).
In the drawing, grooves in the depth direction of the drawing) are formed of diffraction gratings formed side by side at a pitch of, for example, 600 lines / mm. The sample light from the measurement sample 4 passing through the first entrance slit 241 and the second entrance slit 242 are formed. The reference light from the reference plate 5 that has passed through is divided into wavelengths, and the light is reflected toward the plane reflecting mirror 31 slightly upward in FIG.

With such a configuration, the light emitted from the light source 11 is restricted by the restricting frame 12, is reflected by the toroidal mirror 13, becomes parallel light, and is defined by CIE or JIS. The opening for measurement 3
The measurement aperture 3 and its vicinity are illuminated at an illumination angle that satisfies (45 ± 8) ° with respect to the normal 3n.

As shown in FIG. 5A, the illumination range 15 of the illumination unit 10 is a combination of a circular portion including the entire measurement opening 3 and a rectangular portion including most of the reference plate 5. It has a shape. The entirety of the measurement opening 3 is
The reference plate 5 is illuminated from almost all directions by light passing through the C-shaped portion 12b of the second opening 12a, and most of the reference plate 5 is irradiated from almost one direction by light passing through the fan-shaped portion 12c of the opening 12a of the restriction frame 12. Illuminated.

Returning to FIG. 1, the sample light and the reference light diffusely reflected by the measurement sample 4 and the reference plate 5 are both
The light is reflected by the plane reflecting mirror 21 to form the imaging lenses 22 and 2.
3 are focused by the first entrance slits 24, respectively.
It passes through the first and second entrance slits 242.

As described above, the first entrance slit 241
The measurement aperture 3 and the measurement aperture 3 are arranged at positions conjugate to each other with respect to the optical means including the plane reflecting mirror 21 and the imaging lenses 22 and 23, and therefore, as shown in FIG.
A range passing through the entrance slit 241, that is, the measurement range 16 of the measurement sample 4 arranged in contact with the measurement opening 3.
Means that the shape of the first entrance slit 241 is
The range is projected at a magnification of 23.

The second entrance slit 242 and the reference plate 5
Means that the optical means composed of the plane reflecting mirror 21 and the imaging lenses 22 and 23 are arranged at positions substantially conjugate with each other, and as shown in FIG. 5B, the area passing through the second entrance slit 242. That is, the measurement range 17 of the reference plate 5 is such that the shape of the second entrance slit 242 is
The area is projected at a magnification of 2, 23.

As shown in FIG. 5B, the measurement range 16 of the sample light and the measurement range 17 of the reference light are both included in the illumination range 15.

Returning to FIG. 1, the first and second entrance slits 24
The sample light and the reference light that have passed through the light sources 1 and 242 are respectively converted into parallel light by the field lens 25, are incident on the spectroscopic unit 30, are separated for each wavelength, and are reflected. The light reflected by the spectroscopy unit 30 passes through the field lens 25 again, is reflected upward by a plane reflecting mirror 31 in the figure, and forms an image on the photoelectric conversion element of the detection unit 40.

As shown in FIG. 6, the detection section 40 has two detection rows 41 and 42 and is provided on a sensor substrate 401. The detection rows 41 and 42 are arranged on a one-chip silicon wafer in a spectral wavelength range (for example, 400 nm in this embodiment).
A plurality of photoelectric conversion elements 43 are arranged and formed corresponding to the spectral wavelength pitch (for example, 10 nm in the present embodiment) over the wavelength range of about 700 nm. The sample light that has passed through the first incident slit 241 is incident on the detection row 41, and the reference light that has passed through the second incident slit 242 is incident on the detection row 42. The photoelectric conversion element 43 is composed of, for example, a photodiode and outputs an electric signal (a current signal in the case of a photodiode) according to the light intensity. A corresponding electric signal is obtained. In the detection rows 41 and 42, light having the same wavelength is incident on the photoelectric conversion elements 43 arranged side by side.

As shown in FIG. 7, the processing section 50 includes circuit blocks 51 to 60 made up of various electronic components, and these circuit blocks 51 to 60 are disposed on a processing circuit board 501.

The current signals output from the photoelectric conversion elements 43 of the detection columns 41 and 42 of the detection unit 40 are converted into voltage signals by a current-voltage conversion circuit 51, and are switched by a multiplexer 52 to be sequentially amplified. The signal is amplified by the circuit 53, converted into a digital value by the A / D converter 54, and input to the CPU 55.

The CPU 55 controls the operation of each section of the spectrocolorimeter 1. That is, the measurement switch of the operation display section 2 is pressed, and the operation signal is transmitted to the input / output IC 59.
When input through the light source 1, the light emitting circuit 56 is controlled to control the light source 1
1 is caused to emit light. The EEPROM 57 stores a dark offset obtained by measuring without emitting light from the light source 11 and white calibration data when a white calibration plate having a known spectral reflectance is measured as the measurement sample 4. The RAM 58 temporarily stores the measurement value input from the A / D converter 54.

Then, the spectral reflection characteristics of the measurement sample 4 are calculated using the offset and white calibration data stored in the EEPROM 57 and the measured values stored in the RAM 58. At this time, if the output value of the reference light at the time of performing white calibration is M1, the output value of the reference light at the time of measurement is M2, and the output value of the sample light at the time of measurement is R1, R2 = R1 × (M2 / M1 The correction value R2 corrected by the above is set as the spectral reflection characteristic of the measurement sample 4. Thereby, the light source 11 at the time of calibration and at the time of measurement is obtained.
The error due to the variation of the light emission intensity is corrected.

The calculated spectral reflection characteristics are stored in the input / output IC 59
Via the interface IC 60 and output to an external device via the interface IC 60.

As described above, according to the present embodiment, the reference plate 5 is arranged near the measurement opening 3 where the measurement sample 4 is arranged to face, and the optical system including the plane reflecting mirror 21 and the imaging lenses 22 and 23 is provided. By means, the sample light from the measurement sample 4 is guided to the first entrance slit 241 of the mask plate 24, and the reference light from the reference plate 5 is guided to the second entrance slit 242 of the mask plate 24. Therefore, there is no need for an additional optical unit for guiding the reference light, so that the apparatus configuration can be simplified and the cost can be reduced.

Further, in the present embodiment, the reference plate 5 is placed on the opening surface of the measurement opening 3 so that the specular reflection light of the illumination light from the illumination unit 10 with respect to the reference plate 5 is directed to the plane reflecting mirror 21.
Are arranged at an angle. Here, the reference plate 5
Is arranged parallel to the opening surface of the measurement opening 3. The measurement sample 4 is illuminated from almost all directions at an incident angle of 45 ° by the light passing through the opening 12b (FIG. 3), while the reference plate 5 is illuminated by the light passing through the opening 12c (FIG. 3). Since illumination is performed from only one direction at an incident angle of 45 °, the illuminance on the reference plate 5 is lower than the illuminance on the measurement sample 4. As the reference plate 5, a smooth plate having a high spectral reflectance is usually used. However, since the illuminance is low and the light is incident at 45 °, the amount of reflected light in the direction of the plane reflecting mirror 21 perpendicular to the opening surface is small. It will be less. Further, if a smooth plate having a high spectral reflectance is used as the reference plate 5, the specular reflection component escapes in the direction opposite to the incident direction, so that stray light increases.

On the other hand, in the present embodiment, the reference plate 5
Is inclined with respect to the opening surface of the measurement opening 3 so that the specular reflection component is directed toward the plane reflecting mirror 21, so that the output signal of the reference light can be increased and the stray light can be increased. Can be suppressed. Thereby, the S / N in the processing unit 50 can be improved. In this case, the output level of the reference light can be further increased by forming the reference plate 5 from a material having a somewhat low diffusivity, that is, a material that reflects the incident light somewhat specularly.

In the present embodiment, the width (the horizontal dimension in FIG. 4) of the second entrance slit 242 of the mask plate 24 is larger than the width of the first entrance slit 241. The first entrance slit 241 allows the sample light from the measurement sample 4 to pass therethrough, and its size (width) is determined based on the measurement wavelength pitch designed as the specification of the spectrophotometer 1. On the other hand, in the case where the light source includes a bright line like a xenon lamp, the second incident slit 242 through which the reference light from the reference plate 5 passes needs to match the degree of including the bright line between the sample light and the reference light. Therefore, it is necessary to exactly match the width of the first entrance slit 241.

However, in the present embodiment using a tungsten lamp having a continuous spectrum that does not include a bright line as the light source 11, it is not necessary to make the width of the second entrance slit 242 coincide with the width of the first entrance slit 241. . The purpose of measuring the reference light reflected by the reference plate 5 is to monitor the light amount of the light source 11 in order to prevent the influence of the light amount fluctuation of the light source 11 during calibration and measurement, as described above. Since the wavelength purity may be lower than that of the sample light, the width of the second entrance slit 242 can be increased.

Therefore, in the present embodiment, the width of the second entrance slit 242 is set to about twice the width of the first entrance slit 241, thereby increasing the output signal of the detection array 42 due to the reference light. As a result, the S / N of the processing unit 50 can be further improved. As a result, the spectrophotometer 1
, That is, the reproducibility of measurement can be improved.

In this embodiment, a tungsten lamp is used as the light source 11. However, since the radiant energy of the tungsten lamp contains many infrared wavelength components, the measurement sample 4 may be heated as it is. become. On the other hand, since the substance has a characteristic (thermochromism) that the reflectance changes according to the temperature, it is difficult to accurately measure the color when the temperature of the measurement sample 4 changes. For example, in a red color of a BCRA tile often used as a color standard, a color change of ΔE * ab ≒ 0.1 occurs at a temperature change of 1 ° C.

Therefore, according to the present embodiment, since the infrared cut filter 14 is disposed immediately inside the measurement opening 3, the infrared wavelength component is cut off. Can be prevented from being heated, whereby a decrease in measurement accuracy can be prevented.

Further, since the measurement opening 3 is closed by the infrared cut filter 14, it is possible to prevent dust or the like from entering the inside from the measurement opening 3, and the infrared cut filter 14 functions as a dust-proof glass. Will also have.

When the light from the light source 11 is reflected by the toroidal mirror 13, the light from the light source 11 becomes substantially parallel.
In addition, since the toroidal mirror 13 is disposed, even if the distance between the measurement opening 3 and the measurement sample 4 slightly changes, illumination with a small change in the illuminance distribution and a small change in the intensity can be performed. That is, when the light beam applied to the measurement sample 4 is evaluated in a cross section passing through the axis of the toroidal mirror 13, the light beam does not diverge or converge even if the position of the sample surface changes.
It can be said that the change in illumination intensity is small. As a result, a change in the measurement result due to a position change of the measurement sample 4 is reduced, and the colorimetry can always be performed with a constant measurement accuracy.

Next, the position adjustment of the detection unit 40 will be described with reference to FIGS. FIGS. 8A and 8B are diagrams for explaining the position adjustment of the detection unit. FIG. 8A is a plan view of the inside of the spectrophotometer 1, and FIG. FIG. 9 is a diagram illustrating the spectral responsivity of the photoelectric conversion element, and FIG. 10 is a diagram illustrating a conventional position adjustment of the spectral unit 30 and the detecting unit 40.

The sensor board 401 provided with the detection rows 41 and 42 shown in FIG. 6 is mounted on a processing circuit board 501 as shown in FIG. 8B. The sensor board 401
In order to correct the shift of the spectral imaging position on the detection rows 41 and 42 due to the component error and the arrangement error of the spectral unit 30,
The position with respect to the spectroscopy unit 30 is configured to be adjustable in a two-dimensional direction.

As shown in FIG. 8, the light receiving section 20 and the spectral section 3
The optical table 101 to which 0 and the like are fixed has a rectangular plate shape, and at its four corners, for example, a cylindrical base plate mounting portion 102,
103, 104 and 105 are erected. A female screw 106 is provided at the upper end of the base plate mounting portion 102, and a long hole 111 is formed in a corresponding position of the base plate 110 in a direction indicated by an arrow X in FIG.
5 also has the same structure as the base plate mounting portion 102.
Then, after adjusting the position of the base plate 110 in the X direction, the base plate 110 is fixed by the fixing screw 112 or the like.

Further, guide shafts 113 and 114 are protruded at appropriate positions on the base plate 110, and elongated holes 121 and 122 which are long in the direction of arrow Y in the figure are respectively provided at two corresponding positions on the slide plate 120. Has been drilled. Further, female screws 116 and 117 are provided at appropriate places on the base plate 110,
Elongated holes 124 and 123, which are long in the arrow Y direction in the figure, are formed at two locations corresponding to those of the slide plate 120, respectively. After adjusting the position of the slide plate 120 in the direction of the arrow Y, the slide plate 120 is fixed to the base plate 110 by the fixing screws 126 and 125.

The slide plate 120 is further provided with protruding positioning shafts 131, 132, and these shafts 131, 13
2, a female screw (not shown) is provided. A hole is formed in a corresponding position of the processing circuit board 501, and the processing circuit board 501 is fixed to the slide plate 120 by fixing screws 502 and 503. Further, for fine adjustment of the positional relationship between the base plate 110 and the slide plate 120, a small hole 118 is formed in the base plate 110, and a long hole 127 is formed in the slide plate 120.

As described above, the sensor substrate 401 is fixed to the processing circuit substrate 501, and the processing circuit substrate 501 is fixed to the slide plate 120 via the positioning shafts 131 and 132, while the spectroscopic unit 30 is fixed to the optical table 101. It is fixed to. Accordingly, the base plate 110 is adjusted in the X direction with respect to the optical table 101, and the slide plate 1 is adjusted with respect to the base plate 110.
When the sensor 20 is adjusted in the Y direction, the sensor substrate 401 is adjusted in the X and Y directions with respect to the spectral unit 30.

In FIG. 8, the adjustment in the direction of the arrow X is an adjustment for forming an image of the sample light on the detection row 41 and an image of the reference light on the detection row 42, and is an adjustment in the direction of the arrow Y. The adjustment is an adjustment for adjusting the direction of the wavelength dispersion to match the predetermined wavelength of the split light with the position of the photoelectric conversion element 43 (FIG. 6).

In the adjustment in the direction of the arrow X, an adjustment jig (not shown) provided with a screen displaying the sensor area is attached in place of the processing circuit board 501 in advance, and light of a specific wavelength is passed through the measurement opening 3. And projecting it on an adjustment jig to observe the position of the image.

Next, the adjustment in the arrow Y direction will be described. When light of a specific wavelength is incident from the measurement opening 3 with the adjustment jig removed and the processing circuit board 501 attached, an output signal α is obtained from one photoelectric conversion element 43 as shown in FIG. , An output signal β is obtained from the adjacent photoelectric conversion element 43. Then, the slide plate 120 is adjusted and fixed so that the ratio β / α becomes a predetermined value.

For fine adjustment of the slide plate 120, an adjustment tool 133 is used. The adjusting tool 133 has a projection 133a at an eccentric position at the tip. Then, the protrusion 133a of the adjustment tool 133 is inserted into the small hole 1 of the base plate 120.
By inserting the tool body into the elongated hole 127 of the slide plate 120 and rotating the tool body, the positional relationship between the base plate 110 and the slide plate 120 can be finely adjusted.

The adjustment method according to the present embodiment will be compared with a conventional adjustment method. The optical condition for comparison is that the focal length of the field lens 25 is 47.5 m in the present embodiment.
m, the number of grooves in the diffraction grating 30 is 600 / mm.

Conventionally, as shown in FIG. 10, by rotating a diffraction grating 30 as a beam splitting unit in the direction of arrow Z,
Adjustment of the wavelength dispersion direction (arrow Y direction) was performed. Under the above optical conditions, if an attempt is made to achieve an adjustment accuracy of 1 nm by rotating the diffraction grating 30, an angle adjustment accuracy of about 1 minute is required for the rotation angle of the diffraction grating 30. If the holder holding the diffraction grating 30 is fixed by screwing at a position 10 mm from the center of rotation, a one-minute rotation angle change corresponds to a change of about 0.003 mm at the screw-fixed part.

On the other hand, if it is attempted to achieve an adjustment accuracy of 1 nm according to the above embodiment, the movement amount of the processing circuit board 501 will be 0.
03 mm, and comparing the error sensitivity of the screwing position between the two, the method of the above embodiment is about 10 times smaller than the conventional method.
According to the method of the present embodiment, it is possible to reduce the problem that the fixing position changes at the time of screwing.

FIG. 11 is a diagram showing another adjustment method.
(A) is a side view, (b) is a BB line sectional view of (a). The same components as those in FIG. 8 are denoted by the same reference numerals. A screw holding portion 141 is provided on the base plate 110, and the screw holding portion 141 has a fitting hole 142. Slide plate 1
20 is provided with a screw receiving portion 143, and the screw receiving portion 143 is provided with a female screw 144. And
The adjusting screw 145 is fitted in the fitting hole 142 and is screwed with the female screw 144. A compression spring 146 is disposed on the screw portion of the adjusting screw 145, and the slide plate 120 is biased by the compression spring 146. Have been.

According to the configuration of FIG. 11, the positional relationship between the base plate 110 and the slide plate 120 can be changed by simply turning the adjustment screw 145 without using the adjustment tool 133 as shown in FIG. It can be adjusted in the Y direction.

The present invention is not limited to the above embodiment, but can adopt the following modified embodiments.

(1) In the above embodiment, a tungsten lamp is used as the light source 11, but the invention is not limited to this.
For example, another lamp such as a xenon lamp may be used. In this case, when a light source including a bright line such as a xenon lamp is used, the size of the second entrance slit 242 may be the same as the size of the first entrance slit 241.

(2) As shown in FIG. 12, the reference plate 5 may be arranged in parallel with the measurement opening 3.
In this case, what is necessary is just to employ | adopt the thing with favorable diffusivity as the reference plate 5. FIG.

(3) In the above embodiment, the measurement sample 4 is illuminated from almost all directions. However, the invention is not limited to this. By arranging the toroidal mirror 13 in a divided manner, it can be illuminated from one or more directions. It may be. Further, the toroidal mirror 13 may be made of a transparent material, and the total reflection on the back surface may be used. In this case, vacuum deposition of metal or the like for reflection can be omitted.

(4) The configuration of the illumination unit 10 is not limited to the above embodiment. For example, as shown in FIG. 13, a light source 11 and a projection lens 151 may be provided to illuminate the measurement sample 4 from one direction. Also, toroidal mirror 1
3 is provided with a focusing lens and a flat reflecting mirror in place of the light source 1
The light from 1 may be made into parallel light and illuminated from a 45 ° direction.

Further, instead of the 45/0 geometry in the above embodiment, d / 0, 0 / d geometry may be used. FIG.
Is a diagram showing an example of a d / 8 geometry, which is a type of d / 0 geometry, in which an integrating sphere 160 is used as the light source 11.

In FIG. 14, the integrating sphere 160 has a light source opening 161, a measurement opening 162, and a light receiving opening 163. The light receiving opening 163 is inclined by 8 ° with respect to a normal 162 n of the measurement opening 162. It is provided in the direction which was set.
High reflectivity of the inner wall 160a such BaSO ₄ of the integrating sphere 160, the high diffusivity of white paint is painted.

When the lamp 164 arranged in the light source opening 161 emits light, the sample 4 arranged opposite to the measurement opening 162 is diffusely illuminated due to multiple reflections on the inner wall 160a, and the reflected light is subjected to a method. 8 ° to line 162n
The component in the direction is guided to the spectral unit 30 by the light receiving unit 20.

At this time, in the inner wall 160a of the integrating sphere 160, in the vicinity of the measuring aperture 162 and the light receiving aperture 1
The light reflected from the predetermined area 5 a on the opposite side to the side 63 (the left side of the measurement opening 162 in the figure) is split
And used as reference light. That is, the predetermined region 5a functions as the reference plate in the above embodiment.

According to this embodiment, since the reflected light from the predetermined area 5a is used as the reference light, it is not necessary to separately provide a reference plate, and the number of components can be reduced. Further, since the predetermined region 5a is a part of the inner wall 160a of the integrating sphere 160, it is slightly inclined toward the light receiving opening 163, and a predetermined light intensity can be secured as the reference light.

[0081]

As described above, according to the first aspect of the present invention, the reference plate is arranged near the measurement opening where the measurement sample is opposed to the sample plate, and the reference light is reflected by the sample light reflected by the measurement sample and the reference plate. Since the reflected reference light is guided to the first opening and the second opening, respectively, by the optical means, the configuration of the apparatus can be simplified by sharing the optical means, and as a result, the cost can be reduced. it can.

According to the second aspect of the present invention, the measurement opening and the first opening are disposed at positions conjugate with each other with respect to the optical means, and the reference plate and the second opening are positioned at positions substantially conjugate with each other with respect to the optical means. The image in the measurement range of the sample light and the reference light can be suitably guided to the spectroscopic means.

According to the third aspect of the present invention, the range including the measurement aperture and the reference plate is illuminated by the illumination means from an angle inclined by 45 ° with respect to the normal line of the measurement aperture, and the measurement is performed by the optical means. Since the component of the light reflected by the sample along the normal line of the measurement aperture is guided to the first aperture, a simple configuration can be used to provide a 45 ° illumination and vertical light reception geometry device specified by the CIE. Can be realized.

According to the fourth aspect of the present invention, the reference plate is arranged so as to be inclined with respect to the opening surface of the measurement opening so that the regular reflection light of the illumination light from the illumination means is directed to the optical means. Therefore, since the light intensity of the reference light reflected by the reference plate increases, the S / N of the electric signal corresponding to the light intensity of the reference light output from the detecting means increases, thereby increasing the reproducibility of the measurement. Can be improved.

According to the fifth aspect of the present invention, since the size of the second opening is larger than the size of the first opening, the light intensity of the reference light reaching the detecting means increases, whereby the output from the detecting means is increased. Since the S / N of the electric signal according to the light intensity of the reference light increases, the reproducibility of the measurement can be improved.

According to the sixth aspect of the present invention, an infrared cut filter for absorbing light having a wavelength in the infrared region is interposed between the illumination means and the optical means and the measurement aperture. Since the light of the wavelength is not irradiated on the measurement sample, the temperature rise of the measurement sample can be suppressed even if the same measurement sample is repeatedly measured, whereby a certain measurement accuracy can be maintained.

According to the seventh aspect of the present invention, the measurement opening is closed by the infrared cut filter, so that the infrared cut filter prevents dust from entering the inside of the apparatus from the measurement opening. , A dustproof effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a spectrophotometer as one embodiment of a reflection characteristic measuring device according to the present invention.

FIG. 2 is a plan view of the spectrocolorimeter.

FIG. 3 is a front view of a restriction frame.

FIG. 4 is a front view of a mask plate.

FIGS. 5A and 5B are partial plan views showing an illumination range and a measurement range.

6A and 6B are diagrams showing a detection unit, wherein FIG. 6A is a side view and FIG. 6B is a front view.

FIG. 7 is a block diagram illustrating an electrical configuration of the spectrophotometer.

FIG. 8 is a diagram for explaining position adjustment of a detection unit;
(A) is a top view inside a spectrocolorimeter, (b) is the same side view.

FIG. 9 is a diagram showing the spectral responsivity of a photoelectric conversion element.

FIG. 10 is a diagram illustrating a conventional position adjustment of a spectral unit and a detecting unit.

11A and 11B are diagrams for explaining another method of adjusting the position of the detection unit, where FIG. 11A is a plan view and FIG. 11B is a side view.

FIG. 12 is a diagram showing another arrangement of the reference plate.

FIG. 13 is a diagram showing another configuration of the lighting unit.

FIG. 14 is a diagram illustrating another configuration of the illumination unit.

[Description of Signs] 1 Spectrophotometer 3 Measurement aperture 4 Measurement sample 5 Reference plate 10 Illumination unit (illumination unit) 11 Light source 13 Toroidal mirror 20 Light receiving unit 21 Planar reflecting mirror (optical unit) 22, 23 Imaging lens ( Optical means) 24 mask plate 241 first entrance slit (first opening) 242 second entrance slit (second opening) 30 spectral unit (spectral unit) 40 detecting unit (detecting unit) 41, 42 detection column 50 processing unit (signal) Processing means) 55 CPU

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Miyashita 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Norio Ishikawa 2-3-3 Azuchicho, Chuo-ku, Osaka-shi 13 Osaka International Building Minolta Co., Ltd. (72) Isao Nishimoto, Inventor 2-3-1, Azuchicho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd. (72) Inventor Shinsuke Fukuchi, Aichicho Chuo-ku, Osaka-shi 3-13-13 Osaka International Building Minolta Co., Ltd. F-term (reference) 2G020 AA04 AA08 BA17 CB05 CB25 CB43 CB54 CC26 CC42 CD38 DA12 DA22 2G059 AA02 BB10 EE02 EE13 FF09 HH02 JJ01 JJ11 JJ11 JJ13 MM12 NN05

Claims (7)

[Claims] 1. A measurement opening in which a measurement sample is opposed to a reference plate, a reference plate disposed near the measurement opening, an illuminating means for illuminating a range including the measurement opening and the reference plate, Spectroscopic means for illuminating light from the illuminating means being arranged in a region where the sample light reflected by the measurement sample and the reference light reflected by the reference plate are guided, and spectrally separating the sample light and the reference light, respectively. A mask plate disposed on the incident light side of the spectroscopic means and having a first opening through which the sample light passes and a second opening through which the reference light passes; and a mask plate disposed on the incident light side of the mask plate; Optical means for guiding the reference light to the first opening and the second opening of the mask plate, respectively, and an electric signal corresponding to the light intensity of the sampled light that has been separated is output for each wavelength, and the light is split. A detection unit that outputs an electric signal corresponding to the light intensity of the reference light for each wavelength; and a signal processing unit that calculates a spectral reflection characteristic of the measurement sample using each electric signal output from the detection unit. A reflection characteristic measuring device. 2. The reflection characteristic measuring apparatus according to claim 1, wherein the measurement opening and the first opening are arranged at positions conjugate with each other with respect to the optical means, and the reference plate and the second opening are arranged at the optical means. A reflection characteristic measuring device, wherein the reflection characteristic measuring device is disposed at a position substantially conjugate to each other. 3. The reflection characteristic measuring apparatus according to claim 1, wherein the illuminating means illuminates the range from an angle inclined by 45 ° with respect to a normal to the measuring aperture. Is a device for guiding a component of the light reflected by the measurement sample along a normal line of the measurement opening to the first opening. 4. The reflection characteristic measuring apparatus according to claim 3, wherein the reference plate is arranged such that specular reflection light of illumination light from the illumination means is directed to the optical means with respect to an opening surface of the measurement opening. A reflection characteristic measuring device characterized by being arranged at an inclination. 5. The reflection characteristic measuring device according to claim 1, wherein the size of the second opening is larger than the size of the first opening. 6. The reflection characteristic measuring apparatus according to claim 1, wherein an infrared cut filter for absorbing light having a wavelength in an infrared region is provided between the illumination means and the optical means and the measurement aperture. A reflection characteristic measuring device, characterized in that: 7. The reflection characteristic measuring apparatus according to claim 6, wherein the measurement opening is closed by the infrared cut filter.