JPS58143246A - Optical measuring device - Google Patents

Abstract

PURPOSE:To select an aperture with compact constitution and high positioning accuracy by selecting the combination of respective plural apertures and magnifying lenses, and disposing the selected combination on the optical axis of an imaging optical system. CONSTITUTION:A holder 60 having apertures S10-S30 of different diameters and magnifying lenses 51-53 differing in magnifications are provided. Apertures of 9 kinds of diameters are realized by combining 3 kinds of such apertures and 3 kinds of the magnifying lenses.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical measuring device for measuring optical properties of a sample to be measured such as a material or printed matter, such as optical density, transmittance, reflectance, etc.

Such optical measurement devices are used, for example, in scanners, concentration needles, microphotometers, etc., and have imaging optics that form an image of a sample to be measured whose optical properties are to be measured on a plane perpendicular to the optical axis. and a focusing optical system that focuses the image formed on this plane and generates a signal for measuring the optical properties of the sample. Conventionally, in the measurement of such optical properties, in order to select the area of the measurement target part of the sample to be measured, a light shielding plate having an aperture of a desired size and shape is placed at the position of the image forming plane. was taking measurements. Although circular or rectangular aperture shapes are often used, it is necessary to prepare multi-shaped apertures with different dimensions depending on the purpose of measurement.

For this purpose, in conventional optical measuring devices, a single disk with a large number of apertures of different dimensions arranged in a circular shape is used as the aforementioned light shielding plate, but as the number of types of apertures increases, the outer diameter of the disk increases. becomes large, making it difficult to construct the entire device including an operating mechanism for selecting a large number of apertures on such a disk into a compact VCvt. Moreover, such a disk with a large number of apertures k 11"ti is
As the diameter becomes larger, the inertia of rotational movement increases, and it is therefore difficult to align the selected aperture with the optical axis of the optical system with high precision.

Therefore, it is an object of the present invention to overcome the drawbacks of the prior art and to provide an optical measuring device having a compact configuration and actually having (3) a large number of types of apertures.

Another object of the present invention is to provide an optical measuring device that can select an aperture with high positioning accuracy.

These objectives are achieved by the following optical measuring device according to the invention. That is, this device includes a light-shielding plate located at the above-mentioned in-plane pressure position and having a plurality of apertures with different dimensions, an imaging optical system including a plurality of magnifying lenses with different magnifications, and a combination of the plurality of apertures and the plurality of magnifying lenses. By selecting all of the combinations and placing the aperture and magnifying lens selected in this way on the optical axis of the imaging optical system, the optical properties of the area on the sample to be measured are determined. The size is selected.

Next, the optical measuring device according to the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram showing, as an example, a scanner to which the optical measuring device according to the present invention can be applied (4). In the same figure, the cylindrical surface of the rotating drum 10 drawn with imaginary lines is actually made of a transparent material, and a 3ft set of samples such as photographic materials or printed materials for measuring optical density, transmittance, reflectance, etc. Ru.

Inside this rotating drum 10, one arm 16 of a U-shaped casing 12, also shown in phantom lines, is inserted in the axial direction of the drum, and the other arm 14 is inserted along the surface of the drum 10. arranged in parallel. As shown in the figure, a light source 1 is arranged inside one arm 16 of the housing 12, and a light receiver 8 such as a photodiode is arranged in the other arm 14. arms 16 and 1
An optical system consisting of suitable lenses and mirrors is arranged inside the optical system 4, and its optical axis comes out from the light source 1 as shown by the solid line 18, passes through the sample 3 on the drum 10, and reaches the optical receiver 8. As a result, the optical density of the sample 3 is
Light corresponding to the transmittance and reflectance is received by the light receiver 8, and such optical characteristics of the sample 3 can be measured. Note that this example shows the case where sample 3 is optically transmissive, but when measuring an optically reflective sample, both the illumination system and the light receiving system of the optical system should be placed outside the drum. A location method is used.

An example of a conventional optical measuring device applied to such a scanner is shown in FIG. 2. In this figure, for convenience of explanation, the optical axis 18 in FIG. 1 is shown as a straight line. Similar elements are designated by the same reference numerals. In this conventional apparatus, light generated from a light source 1 is focused onto a sample 3 by a condenser lens 2, and a light spot of a desired diameter is formed thereon.

The part of the sample 3 illuminated by this light spot is imaged by a pickup lens 4 and a magnifying lens 5, and the image is formed on a disk 6. Focusing on the surface of the disc 6 is performed by moving the pickup lens 4't in the optical axis direction as shown by the arrow.

As shown in the figure, the disc 6 has a plurality of apertures 81 to S9 (nine in this example) having different diameters, and by rotating the disc 6 as shown by arrow B, a desired diameter can be obtained. Aperture can be selected. The entire disk 6 is optically opaque and quickly cuts light, and only the apertures 81 to S9 are optically transparent. For example, in this figure, the aperture S9 is located on the optical axis, so that of the image of the sample 3 formed on the surface of the disk 6, only the opening of the aperture S9 is focused onto the light receiver 8 by the focusing lens 7. be done. For example, the diameter dimensions of apertures 81 to S9 are 1 to 32 mm as shown in Table 1, and if the magnification of the light receiving system from sample 3 to the aperture is 100, then sample 3
The diameter of the measurement area above is 10 to 320 μm.

(7) Table 1 As described above, in the conventional method, the area of the area on the sample 3 to be optically measured is is selected. Therefore, as the number of types of apertures increases, the size of the disk 60 increases, and the housing 1 that accommodates this optical system increases.
It becomes much larger than 2.

FIG. 3 is a diagram conceptually showing the configuration of an embodiment of the optical measuring device according to the present invention. In the figure (8), elements similar to those in FIG. 2 are designated by the same reference numerals. According to the invention, instead of the conventional disc 6, a plurality of apertures SIG with diameter A are provided.

A holder 60 is provided having apertures 820 and S30, the holder 60 being optically opaque except for portions of the apertures 810, 820 and 83G. Also, instead of the single magnifying lens 50 in the conventional system, three magnifying lenses 51, 52 and 53 with different magnifications are provided. In this example, apertures 810, 820 and S30
The diameters of 1 and 411II are respectively shown in Table ■.
+ and 16am, and the magnifications M1, M2 and M3 of the magnifying lenses 51, 52 and 53 are 10
0.66.6 and 50. Therefore, as shown in Table ■, these three types of apertures and three
By combining different types of magnifying lenses, an aperture with a diameter of type 9a, which is substantially the same as the conventional device shown in FIG. 2, can be realized. This means that the diameters of the apertures 81 to S9 shown in Table 1 are 3 types each as shown in Table 2.
It can be classified into groups, and each group has an aperture SIO,
This is due to the fact that the diameter ratio between 82G and 830 is the same.

Note that these numerical values are merely examples for explaining the present invention, and of course the present invention is not limited thereto.

Selection of apertures 810, S20, and S3G is performed by moving holder 60 in the force direction of arrow C as shown. Similarly, the magnifying lenses 51, 52 and 53 are selected by moving their supports (not shown) in the direction of the arrow. For example, as shown in this figure,
Assuming that the aperture 820 and the magnifying lens 52 are selected, the diameter of the aperture above the sample 3 is substantially 60 μm, as shown in Table 1. This is the same as selecting aperture S5 in the conventional device shown in FIG.

The selection of such apertures 810, 820 and 830, as well as the selection of magnifying lenses 51, 52 and 53, may be performed by a manual operating mechanism, but may also be performed by an electric drive mechanism such as a motor or solenoid. It is advantageous to use In the case of an electric drive mechanism, when one of the nine aperture diameters shown in Table 1 is selected, the combination of aperture and magnifying lens that achieves this aperture diameter is automatically selected. It's okay.

(11) Since the optical measuring device according to the present invention is configured in this way, it is equipped with an aperture and a magnifying lens, since the types of apertures that can actually be obtained on a trundle are small. The associated mechanisms of the shutter and the magnifying lens can be constructed compactly and can be completely accommodated within the housing of the optical measuring device. Therefore, the entire device can be made into a small base. In addition, in the conventional system, the selection of the aperture is performed by the rotational movement of the disk, and the positioning accuracy is low due to the rotational inertia. However, in the device of the present invention, the selection of the magnifying lens and the aperture is performed by the linear movement. Therefore, the accuracy of aligning the selected magnifying lens and aperture on the optical axis can be made very high. Since the accuracy of the aperture position greatly affects the position on the sample depending on the magnification of the light receiving system, a high n1 degree is important for non-professionals.

Although the optical sub-equipment rt according to the present invention has been described according to the illustrated embodiment α2), the present invention is not necessarily limited thereto. For example, the types of apertures and magnifying lenses are not limited to three types as in the illustrated embodiment, and appropriate types of apertures and magnifying lenses can be used as needed. Also, although the shape of the aperture is circular in this example, other shapes may be used, such as a rectangular aperture, depending on the nature of the sample to be measured or the optical properties to be measured; Although an example in which the optical measuring device according to the present invention is applied to a scanner has been described, the optical measuring device according to the present invention can also be applied to other general densitometers, microphotometers, and the like.

[Brief explanation of the drawing]

Fig. 1 is a diagram conceptually showing the configuration of a scanner as an example to which the optical measurement device according to the present invention can be applied, Fig. 5g2 is a diagram conceptually showing an example of a conventional optical measurement device, and Fig. 3 is a diagram conceptually showing the structure of a scanner as an example to which the optical measurement device according to the present invention can be applied. 1 is a diagram conceptually showing the configuration of an embodiment of an optical measurement device according to the invention. 4...Pickup lens 7...
...Focusing lens 51.52.53...Magnifying lens 60...
···holder

Claims (1)

[Scope of Claims] 1. A group of measurement samples whose optical properties are to be measured are placed on a plane perpendicular to the optical axis using an imaging optical system that focuses m on the optical axis. and a condensing optical system that generates light No. 1d to be used for measuring the optical properties of the sample. The above-mentioned Keiken optical system combines a magnifying lens with a magnification of J4 and a number of a, fiIJ! By selecting one of the combinations of several apertures and a plurality of magnifying lenses, and placing the selected aperture and magnifying lens on the optical axis of the 8-pin imaging optical system, An optical measuring device characterized in that -J4 is selected as the size of a region whose optical characteristics are to be measured. 2. The optical measuring device according to claim 1, wherein the light shielding plate and the plurality of magnifying lenses are movable in a direction parallel to the plane.