JPH04283650A - Birefringence measuring device - Google Patents

Abstract

PURPOSE:To enable time for setting a sample to be saved and achieve an accurate measurement by providing a mechanism for retaining a sample sheet so that it can be moved in feed direction and a mechanism for carrying the sample sheet to a measurement position while feeding it intermittently. CONSTITUTION:A distance from a sample edge to an initial measurement position, a sample feed pitch., and a measurement count are set to an operation control portion 30. Then, by allowing the sample sheet to be nipped between a drive roll 9 and a guide roll 15, the roll 9 is driven by a motor for drive 10 and the sample sheet is supported by a sample supporting guide 12 and is carried. Then, the sample edge is detected by a photocell 14, a feed length of the sample sheet is measured by an encoder 11, and feeding is made by a sample feed pitch which is set previously. Then, after sampling a measurement data, marking is made by a marking mechanism 13 to allow a measurement position of the measured sample to be clarified. Then, when a preset measurement count is attained, the measurement is completed.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a birefringence measuring device, and in particular, the optical anisotropy or retardation (corresponding to the stretching balance and orientation degree of film samples, etc.) of optically transparent and translucent samples. This invention relates to a device for measuring.

0002

[Prior Art] A birefringence measuring device uses a specific wavelength to incident polarized light perpendicularly to the sample surface, and measures the transmitted light by passing it through an analyzer and entering a photodetector, and the polarization direction of the polarizer and analyzer is always adjusted. Rotate one rotation relative to the sample while keeping it constant, and from the relationship between the transmitted light intensity at the light receiving element and the rotation angle,
This is to calculate the birefringence and retardation of the sample.

The measurement principle of the birefringence measuring device is summarized as follows. The transmitted light intensity I when the two polarizing plates and the sample rotate once relative to each other is expressed as follows. I=I0 (cos4θ+α2sin4θ)+(
1/2) I0 sin22θ・α・cos δHere,
I: Transmitted light intensity I0: Incident light intensity into the sample θ: Rotation angle α: Ratio of absorption magnitudes of two light waves in the sample δ
: Retardation (phase difference) Next, the formula for calculating retardation is I=Vxma
x cos δ=(4V(π/4)/Vxmax-1-α2
)/2α, the retardation R is determined as R=(λ0/2π) cos-1C. Birefringence is determined by Δn=R/d d : thickness of sample λ0 : measurement wavelength.

In the conventional apparatus, as shown in FIG. 6(a), a part of the sample to be measured is cut out to a certain size, and the sample is fixed in a sample holder for measurement. There were various problems. (a) This measurement method requires a great deal of time and effort to cut out the sample and set it in the sample holder. (b) When performing measurements, the measurement points are limited because the sample is fixed as shown in Figure 6 (b), so measurements around the measured area (portion A in Figure 6 (b)) may not be possible. It is possible. (c) Sample width direction (TD direction) or flow direction (M
Even if you want to know the profile data (direction D), the sample is cut out manually, so deviations occur and accurate profile measurements cannot be made.

[0005]

SUMMARY OF THE INVENTION The present invention reduces the time and effort required to prepare a sample to be measured, as well as the time and effort required to set the sample in a sample holder during measurement.
Moreover, the present invention aims to provide a device that can efficiently perform accurate measurements.

[0006]

[Means for Solving the Problems] The present invention provides an apparatus for calculating optical anisotropy or retardation by measuring changes in the amount of light transmitted through a sample using a specific wavelength. The above-mentioned problems have been solved by a birefringence measuring device characterized by having a mechanism for holding the sample sheet movably in the feeding direction and a mechanism for conveying the sample sheet to the measurement position while feeding the sample sheet intermittently.

[0007]

[Function] Since it has a sample feeding function that allows measurement of long samples, measurement position settings and measurement interval settings can be entered arbitrarily in advance, allowing measurement of locations that were impossible to measure with conventional measuring devices. This makes it possible to measure easily and quickly, display measured data and profile data in the TD direction and MD direction on a CRT, and at the same time output to a printer.

[0008]

[Embodiment] The basic configuration of the birefringence measuring device of the present invention is as follows. Figure 1 is a diagram of the equipment configuration of the device of the present invention, and explains the configuration of the measuring section. (1) is a measurement light source such as a halogen lamp, and (2) is a filter that transmits only a specific wavelength and is attached to a filter holder (3). has been done. (4) is a drive motor for rotating the filter holder (3), (5) is a drive motor for rotating the polarizing plate, (6) and (7).
) is a polarizing plate arranged in parallel Nicols, and (8) is a measuring light detection device.

To explain the structure of the sample transport section, (9) is a drive roll for transporting the sample, (10) is a motor for driving the drive roll (9) for transporting the sample, and (11) is a drive roll for transporting the sample.
is an encoder for measuring the feed length of the sample, (1
2) is a sample support guide for correcting meandering of the sample and supporting the sample; (13) is a marking mechanism for marking the measurement point; (14) is a phototube for detecting the edge of the sample;
) is a guide roll for feeding the sample.

[0010] As an embodiment of the above marking mechanism (13), No. It also becomes possible to print the . (24) is the amplifier of the detection output of the detector (8), (
25) is an A/D converter, (30) is a control/calculation unit that performs data input control and calculations (details will be explained in the system configuration in Figure 4), and (28) displays measurement data and profiles. It is a CRT for

The basic operation of the marking mechanism controlled by the system program will be explained. (b) Receive a signal indicating the end of measurement at one point on the sample sheet. (b) The cylinder of the marking device operates. (c) The marker contacts the edge portion of the sample sheet on the extension line of the measurement point and marks are applied. (Details regarding the marking method will be explained in E) of the explanation of the operation of the apparatus of the present invention to be explained later. )

FIG. 4 is a system configuration diagram of the device of the present invention, where (L) is a bus line, (16) is a CPU, and (17) is a system program (18), a filter control program (19), and a polarizing plate control program. (20) A control program storage section that stores a control program (21) for performing marking control, a data input program for sampling measurement data, and an arithmetic program (22).

(23) is a filter drive motor (4).
Polarizing plate drive motor (5)/roll drive motor (10)
) drive device, (24) is the detection output amplifier of the detector (8), (25) is the A/D converter, (26) is the input/output interface board, and (27) is the motor driver (23). Motor controller for controlling (28
) is a CRT for displaying measurement data and profiles, and (29) is a printer for printing out measurement data and profiles.

The measurement operation of the apparatus of the present invention will be explained based on FIGS. 1, 2 and 4. First, light emitted from a measurement light source (halogen lamp) (1) passes through a filter that transmits only a specific wavelength, which is selected by a filter control program (19), via a fiber. The transmitted measurement light becomes light whose vibration direction is constant through a polarizing plate (6) placed in parallel Nicols, and is irradiated onto the sample. The measurement light that has passed through the sample passes through a polarizing plate (7) and is received by a light receiving element (8).

The data measurement method is such that when the sample stops at the measurement position, the motor controller (27), motor driver (23),
The polarizing plate drive motor (5) is controlled, and the polarizing plates (6), (
7) It rotates once, and the signal of the amount of transmitted light sent during the rotation is sent to the light receiving element (8), the amplifier circuit (24), and the A/D converter (
25), CPU via I/O interface (26)
The data input program (22) samples 360 pieces of data at a time, and the data is processed by an arithmetic program.

Next, the surroundings of the sample feeding mechanism will be explained based on FIGS. 2 and 3. The sample sheet is moved to the driving roll (9
) and the guide roll (15), the sample edge is detected by the phototube (14), the sample is sent a preset distance from the sample edge to the initial measurement position, and sample measurement begins. do.

Next, the operation of the apparatus of the present invention will be explained based on FIG. A) First, set the distance from the sample end to the initial measurement position, set the sample feeding pitch, and set the number of measurements. B) Send the sample to the initial measurement position. C) Determine the wavelength filter using the filter control program (19) in FIG. D) Measurement data sampling E) After the measurement is completed, mark the sample to clarify the measurement location on the sample. (This mark may simply indicate the measurement point, but it also marks the number from the initial measurement position, and furthermore, this number value is sent to the data processing section along with the sampling signal, and the measurement results are tabulated. If used, the comparison between the measurement data and the measurement points on the sample sheet will be ensured.) F) Feed the sample by the preset sample feed pitch. G) Determine whether a preset number of measurements has been reached. If the number of measurements has been achieved for the set value, the measurement is terminated; otherwise, the measurement is continued.

Regarding the operation of the present invention, according to FIG.
This will be further explained while comparing with the conventional method. (1) Conventionally, in order to measure a sample as shown in FIG. 6(a), the sample was cut to a certain size and measured. In addition, sample No. It was necessary to differentiate (organize) a large number of samples by writing.

On the other hand, in the present invention, there is no need to cut the sample into small pieces, the sample can be measured as long as it is, and markings can be applied to the sample to clarify the measurement points on the sample. It is also easy to organize. (2) When using the conventional measurement method to measure samples 1 and 2 in the TD direction as shown in Figure 6(b), the measurement is performed with the sample fixed in the sample fixing holder, so the measured position is The center of the fixed holder window, approximately 5 mmφ, will be measured. Therefore, if you want to measure the part "A" between samples 1 and 2, it is impossible to measure it.

In contrast, in the present invention, if the sample feeding pitch is finely set in advance when measuring a long sample,
It becomes possible to measure the "A" part, which could not be measured conventionally.

[0021]

[Effects of the Invention] The following effects can be obtained by the present invention. 1. The enormous amount of time and effort required to cut out the sample and set the sample during measurement can be significantly reduced. 2. Since it has a sample feeding function that allows long sample measurements, it is possible to easily measure any position without being tied to a specific measurement point. 3 Equipped with a marking mechanism to clearly identify the measurement location, allowing you to mark the sample.
It is also easy to organize samples and match them with measurement data. 4. Accurate profile measurement can be performed even when you want to know profile data in the TD direction or MD direction of the sample.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the entire device (hardware) of the birefringence measuring device of the present invention.

FIG. 2 is an equipment configuration diagram of a sample feeding mechanism and a marking mechanism of the apparatus of the present invention.

FIG. 3 is a configuration diagram of the sample feeding mechanism of the apparatus of the present invention.

FIG. 4 is a schematic system configuration diagram of the device of the present invention.

FIG. 5 is a flowchart showing an example of sample measurement operation of the apparatus of the present invention.

FIG. 6 In FIG. 6, (a) is an explanation of a sample cutting method using a conventional measuring device, and (b) shows a position that could not be measured with a conventional measuring device.

[Explanation of symbols]

1 Measurement light source (halogen lamp) 2
Wavelength filter 3 Filter holder 4 Wavelength filter rotation drive motor 5
Polarizing plate rotation drive motor 6 Polarizing plate 7 Polarizing plate 8 Light receiving element 9 Sample feed drive roll 10 Sample feed drive motor 11 Encoder 12 Sample support guide 13 Marking device 14 Sample edge detection phototube 15 Sample feed guide roll 16
CPU 17 Control program storage section 18
System program 19 Filter control program 20
Polarizing plate control program 21 Sample feeding control/marking control program 22 Data input/calculation program 23 Motor driver 24 Amplifier circuit 25 A/D converter 26 I/O interface 27
Motor controller 28 CRT 29 Printer 30 Arithmetic/control unit L Bus line

Claims (4)

[Claims] Claim 1: A device that calculates optical anisotropy or retardation by measuring changes in the amount of light transmitted through a sample using a specific wavelength, in which a sample sheet is held movably in the feeding direction. A birefringence measurement device characterized by having a mechanism and a mechanism for transporting a sample sheet to a measurement position while intermittently feeding the sample sheet. 2. The birefringence measuring device according to claim 1, further comprising a pair of rolls disposed in front of the measuring position to feed the sample sheet to the measuring position. 3. The birefringence measurement device according to claim 1, further comprising means for marking a measurement point on the sample sheet or a position corresponding thereto. 4. No. 1 from the initial measurement position on the sample sheet. 4. The birefringence measuring device according to claim 3, further comprising means for printing the value.