JPS61145958A - Light projecting and photodetecting device by optical fiber - Google Patents

Abstract

PURPOSE:To obtain a photodetecting area under stable conditions on a measured surface by surrounding the periphery of one optical fiber for photodetection with plural optical fibers for projecting the light and incorporating the light projecting and photodetecting parts. CONSTITUTION:Optical fibers T1-T6 are for projecting the light, irradiates the light to an original 4 and receives the reflecting light by means of an optical fiber J1 for photodetection. Presently when an interval DD of an optical fiber 1 and an original 4, and a diameter of one optical fiber are approximately equal, and then, a light projecting area and a photodetecting area of one optical fiber range respectively over the scope of a diameter of about two times or above that of the optical fiber. Consequently, a light projecting area TT by the optical fibers T1-T6 for projecting the light can wholly cover a photodetecting area J1 of the optical fiber Ji for photodetection, and further, when the plural optical fibers incorporated and composed are closely composed, all places on the original 4 are a light projecting area and a photodetecting area, and therefore, the resolution goes to be infinite.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a light projecting/receiving device using an optical fiber that illuminates a surface to be measured and performs photometry using the optical fiber.

When converting the content of a surface to be measured, such as a document, into an electrical signal, in principle, a photosensor such as an amorphous optical sensor is placed facing the document to convert the shading of the document surface into an electrical signal. can. In practical terms,
When reading a document with high resolution, it is structurally impossible to install many photosensors near the document, and the resolution is limited by the external dimensions of the photosensor, so recently glass A method has been realized in which the amount of light on the document surface is transferred to a distant location using an optical fiber, and the document is read by connecting a photosensor to the end of the optical fiber at that remote location. There is.

FIG. 3 shows a block diagram of a general document reading device. A light source 3 supplies a light amount to a document 4, and the reflected light from the document 4 reaches a photosensor 2 through a light-receiving optical fiber l. The voltage converted from the light source by the photosensor 2 is output as a predetermined voltage value VV by performing dead band setting and offset adjustment, and this voltage VV is input to the display section 6 to display the contents of the document 4. Or,
The data is also input to the data processing unit 7, converted into a digital quantity, and then stored and subjected to predetermined calculations. Light source for realizing such a reading device 3. Optical fiber for receiving light
Various specific examples of the photosensor 2 have been considered.

Figures 4 (A) to (D) show examples of general light emitting and receiving devices used when reading originals. Figure 4 (A) shows an example of a light source 3 such as a fluorescent lamp for color evaluation used on an original The optical fiber 1 is brought close to the original 4 which maintains a certain amount of light intensity, and the amount of light on the original surface is transferred to the photosensor 2, and this photosensor 2 converts the amount of light from the original 4 into an electrical signal. It shows. Then, the original 4 is moved in synchronization with the data processing of the output of the photosensor 2 (-not shown), and the original 4 is moved.
is read. In this case, the light source 3 may keep the luminous intensity on the document 4 constant, or a large shadow may appear, especially when a plurality of optical fibers are provided as shown in FIG. 4(B). Therefore, if the distance between the original 4 and the end of the optical fiber 1 is increased in order to prevent shadows from being created, problems such as deterioration of the resolution will occur.The solution to this problem is as follows. This is an example of the same figure (C), and the light source 3A,
This is a device that irradiates light from two directions 3B. in this case,
A mechanism is required to equalize the brightness on the four sides of the document by the light sources 3A and 3B, and there are drawbacks such as the cost required for this and the cost due to the use of two light sources.

The example in Figure 4 (b) shows the case where two points on the original 4 are measured simultaneously and the difference between them is determined. By installing the above-mentioned optical fibers IA and 2A at the two points, it is possible to detect the effects that occur on the pattern due to ink scattering, dust adhesion, etc. In other words, if original 4 is considered to be a pattern that is printed continuously and flows in the 14N direction, points 4A and 4B are originally the same pattern, but are only shifted by l pitch, so the exact same pattern is printed. If it is a good product, use the photo sensor 2A.
The outputs of and 2B are the same. However, if there is even a slight scattering of ink at either point 4A or point 4B, there will be a difference in the outputs of the photosensors 2A and 2B, so that a defect can be identified. In this case, light sources 3G and 30
variations, deterioration, or light [3G and 30 originals 4]
If there is even a slight difference in the amount of light due to the shadow of the optical fiber itself due to the difference in the incident angle to the second point 4A and 4B, the threshold for detecting a defect will increase by that amount, and the defect will be detected with high precision. It is difficult to realize a detection device.

(Object of the invention) This invention was made due to the circumstances as stated in L.
The purpose of this invention is to use 8$ yu9 under stable conditions within a projection area of a constant light amount on the surface to be measured! -1 + edict 4 capital 1
The western feeling is also smaller.

(Summary of the Invention) The present invention relates to a light emitting/receiving device for photometry of a surface to be measured using an optical fiber, which comprises one light receiving optical fiber and a plurality of light emitting optical fibers, The light-receiving optical fiber is surrounded by the plurality of light-emitting optical fibers that are arranged regularly, so that a secondary light-receiving section is integrated.

(Embodiment of the Invention) FIGS. 1(A) and 1(B) show an embodiment of the present invention, and in FIG. 1(A), optical fiber l is in contact with optical fibers TiNTO and Jl having the same diameter. This shows that it has an integrated structure.

:frJ1 Figure (B) shows a cross-sectional view taken along the AA arrow in Figure (A). Here, optical fiber 〒1-76
is for light projection, and irradiates the original 4 with light, and the reflected light is received by the light receiving optical fiber Jl. It is now known that the gap between the optical fiber 1 and the document 4 and the light projection area of one optical fiber for light beams cover a diameter range that is approximately twice or more the diameter of the optical fiber. Similarly, regarding the light receiving area, it is known that the light receiving optical fiber can detect the amount of light in a range of diameters approximately twice or more the diameter of the optical fiber. Therefore, the light emitting castle made of the light emitting optical fibers T1 to T8 can cover the entire light receiving area JJ of the light receiving optical fiber J1, and is further configured with a plurality of integrated optical fibers 1 in close contact with each other. In this case, all locations on the document 4 become light projecting areas and light receiving areas, so the resolution becomes infinite, and from the opposite perspective, the resolution is determined by the ability of the photosensor. Further, FIG. 2 shows an example of application of the present invention, in which an optical fiber l is arranged on a document 4,
The light emitting optical fibers T1 to T6 are connected to the light II3, and the light receiving optical fiber J1 is connected to the photosensor 2, respectively. Here, the light projection optical fibers T1 to T8 are supplied with light from one light source 3, so the light projection area TT always has a constant light amount, and furthermore, when a plurality of optical fibers 1 are arranged in parallel, Since all of the light projection optical fibers are supplied with light from the same light source, a constant light projection area is always obtained. When measuring the light at two points on the document at the same time and detecting defects such as ink scattering when the same pattern is printed continuously based on the difference between the two points, the amount of light in the light projection area between the two points can be measured. Since they are equal, the threshold for detecting the defect can be almost zero. Also,
Even if the amount of light changes due to deterioration of the light source 3, the light emitting fibers are all given the same amount of light with the same amount changed, so they are not affected by the deterioration of the light source 3.

Although all the optical fibers have the same diameter here, the present invention can be realized even if optical fibers with different diameters are used.
Although the embodiment has been described in which the light-receiving optical fibers are surrounded by a hexagonal tree as in case B, it is also possible, for example, to arrange three light-emitting optical fibers regularly. In short, the present invention can be realized by disposing the light projecting area 11 so as to cover the light receiving area JJ. Furthermore, the light-emitting optical fiber and the light-receiving optical fiber may have exactly the same material and shape, or they may be different, for example, fibers with excellent reflection characteristics only for light-receiving.

(Effects of the Invention) As described above, according to the present invention, since it is not affected by deterioration caused by the light source, it is possible to obtain a light receiving area under stable conditions within a light emitting area under constant light conditions. Furthermore, since the light-receiving optical fiber does not cast a shadow, the distance between the end of the light-receiving optical fiber and the document can be kept to a minimum, making it possible to use an optical fiber-based light projector/receiver with extremely high precision and high resolution. can be realized.

[Brief explanation of drawings]

FIGS. 1(A) and 1(4) are diagrams showing an embodiment of the present invention,
Fig. 2 is a diagram showing an application example of the present invention, Fig. 3 is a block diagram showing a general document reading device, and Figs. 4 (A) to (D).
is a general light emitting/receiving method! It is a figure which shows an example of IC tan. l... Optical fiber for light reception, 2... Photo sensor, 3
...Light source, 4.Document, 5.Voltage amplifier, 6.
...Display section, 7...Data processing section. Applicant's agent Yu Yasugata Mishaya l Painter 2 Figure 3

Claims (1)

[Claims] A light emitting/receiving device for photometry of a surface to be measured using an optical fiber, comprising one light receiving optical fiber and a plurality of light emitting optical fibers, and the plurality of light receiving fibers are connected around the light receiving fiber. A light emitting/receiving device using an optical fiber, characterized in that the light emitting/receiving unit is surrounded by regularly arranged light emitting optical fibers, and a light emitting/receiving part is integrated.