JPH0443927A - Coaxial reflection type color discrimination device - Google Patents

Abstract

PURPOSE:To easily measure the color at the measurement point of a body to be measured by a compact device by aligning the optical axis of an irradiation system with the optical system of a photodetection system substantially and setting the measurement point to a point irradiated with the light from a light source. CONSTITUTION:Transmitted light travels straight and is reflected by a side wall 8 to return to a half-mirror 7, where the light is reflected at 45 deg. to reach a sensor 5. This sensor 5 receives the original reflected light from the body to be measured and also receives the reflected light from the side wall 8. For the solution of this, the side wall surface 8 is slanted to an extent where the reflected light from the side wall surface 8 does not enters the sensor by being reflected by the half-mirror 7. Consequently, the measurement point of the body 10 to be measured can be set to the point which is irradiated with the light from the light source.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for determining the surface color of an fp+ object by DI.

BACKGROUND ART In order to determine the surface color of an object to be measured by 1lFI, light from a light source is irradiated onto the object to be measured, and the reflected light is detected and data processed.

For example, as shown in FIG. 5, a light source 1,
Using a color identification device incorporating a parallel lens 2, a condensing lens 4, a photosensor element 5, and optionally a data processing circuit 6, the light from the light source 1 passes through the parallel lens 2 and becomes parallel light, and the object to be measured is The object 10 is irradiated. The reflected light from the object to be measured is guided to the sensor element 5 through a condensing lens, and the signal generated by the sensor element is inputted to the data processing circuit 6, which determines the color of the object to be measured. I was sure it was the color.

Problems When using the above color identification device, it was necessary to set the distance and position between the object to be measured and the device with some degree of accuracy, and to match the measurement point of the object to be measured with the illumination point and the focus of the light receiving system. . However, since the focal point of the light receiving system cannot be visually recognized, accurate installation has been difficult.

In addition, in order to install it in existing machines for various uses, such as process control, it was necessary to make it compact.

Solution: The present invention includes a light source, a parallel lens that converts light from the light source into substantially parallel light, a half mirror that reflects the light at approximately 45 degrees, and a condenser lens that collects light from an object to be measured. It consists of a light sensor that receives the focused light and a data processing circuit that processes the signal from the light sensor and identifies the color.
This is a coaxial reflective color identification device in which at least a light source, a parallel lens, a half mirror, a condensing lens, and an optical sensor are housed in one case.

A data processing circuit that processes signals from the optical sensor and identifies colors may be installed inside the device case, or the signals may be taken out and processed externally.

The light source 1 is preferably one that outputs a wide wavelength range necessary for measurement, such as an incandescent lamp or a halogen lamp. A halogen lamp that is small and provides high output is preferred.

The parallel lens 2 converts light from a light source into parallel light.

The condenser lens 4 is a lens that condenses reflected light from the object to be measured onto the optical sensor. Is it possible to achieve this purpose with only a parallel lens and a condensing lens? By providing a third lens at the light entrance and exit of this device, the diameter of the received light spot and the projected light can be improved by providing a third lens at the light entrance and exit of this device. The diameter of the light spot and the distance from the object to be measured to the device may be set to desired values.

The optical sensor 5 receives the reflected light and outputs signals corresponding to the three primary colors according to the intensity of the light.

The data processing circuit 6 receives the signal from the optical sensor and performs arithmetic processing to determine the color of the object to be measured.

The half mirror 7 is installed between the parallel lens 2 and the object to be measured lO, and reflects the light from the light source at approximately 45 degrees to illuminate the object to be measured, and also reflects the light from the object to be measured. It is a mirror that transmits light and sends it to the optical sensor.

The half mirror 7 reflects the light from the light source at 45 degrees, but as shown in Figure 2, the transmitted light travels straight, is reflected by the side wall 8, returns to the half mirror, and is reflected at 45 degrees by the half mirror to the sensor. leading to. Therefore, the sensor receives not only the reflected light from the object to be measured but also the reflected light from the side wall 8, and does not measure the color of only the object to be measured.

In order to solve this problem, the side wall surface may be inclined to such an extent that the reflected light from the side wall surface 8 is not reflected by the half mirror 7 and enters the sensor. As shown in FIG. 3, it is preferable to prevent the reflected light from entering the half mirror.

The light entrance/exit of the device case 9 may be simply opened, or may be fitted with a glass plate or the like to allow light to pass through. Further, a third lens 11 may be inserted.

The relationship between this device and the object to be measured is shown in Figure 4. When the object to be measured is irradiated obliquely, only the scattered light enters the optical sensor as reflected light, and the light from the light source itself is excluded. Allows for more accurate measurements.

Effects In the device of the present invention, the optical axis of the irradiation system and the optical axis of the light receiving system are aligned, so simply placing the measurement point of the object at the point to be irradiated with light from the light source allows the object to be irradiated with light. The color of the measurement point can be measured. Furthermore, since the position of the light source is not related to the distance between the object to be measured and the device, the lateral dimension in the figure becomes smaller, making it possible to make the device more compact.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall concept of the present invention. FIG. 2 is a diagram showing reflected light from the side wall. Figure 3 is a diagram with the side walls inclined. lol
Figure 44 shows an example of the use of the present invention. FIG. 5 is a diagram showing a conventional example. l... Light source 2... Parallel lens 4... Condensing lens 5... Optical sensor 6... Data processing circuit 7... Half mirror 8... Side wall 9.
...Case 10...Measurement object patent applicant Kurashiki Boseki Co., Ltd.

Claims (1)

[Claims] 1. A light source, a parallel lens that converts the light from the light source into nearly parallel light, and a half mirror that reflects the light at approximately 45 degrees.
It consists of a condensing lens that condenses light from an object to be measured, a light sensor that receives the condensed light, and a data processing circuit that processes signals from the light sensor and identifies colors. A coaxial reflective color identification device characterized by a lens, a half mirror, a condensing lens, and an optical sensor housed in one case.