JPS58221470A - Method and device for optical reading - Google Patents

Abstract

PURPOSE:To detect existence and direction of moving of a relatively small mark of specified length, by detecting the end of a body or a mark by two sets of light receiving sections and light projecting sections installed at specified distance. CONSTITUTION:Existence and direction of moving of a moving body or a mark having specified length are detected by output of reading semgnets 3. The reading segment 3 consists of optical fiber 1 for receiving light and optical fiber 2 for illumination, and installed at distance corresponding to specified length. Existence and direction of moving of a body or a mark having specified length are read basing on output of the optical fiber 1 for receiving light.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to an optical reading method and device thereof, and in particular to detecting the presence of an object or mark of a specific length (hereinafter referred to as "specific length mark") and the direction of movement thereof. The present invention relates to an optical reading method and apparatus suitable for the invention.

BACKGROUND OF THE INVENTION Conventional optical reading devices detect light from a light source such as a lamp or a light emitting diode using a photodetector such as a photodiode or phototransistor that receives the light through an object to be detected. In addition, the content of the reading is limited to detecting the presence or absence of an object to be detected at a specific position, and as mentioned above, it is necessary to detect the presence of a specific length mark, especially a relatively small specific length mark, and the direction of movement thereof. No applicable equipment was found.

Object of the Invention The present invention has been made in view of the above circumstances, and its object is to provide an optical method suitable for detecting the presence of a relatively small specific length mark as described above and the direction of movement thereof. An object of the present invention is to provide a reading method and device.

The above-mentioned object of the present invention is to provide two sets of light-receiving units, each of which is provided at a distance corresponding to the specific length, in an optical reading system that reads the presence and direction of movement of a moving object or mark having a specific length. This is achieved by configuring the present invention to read the presence of the object or mark having the specified length and the direction of its movement from the output of the means for detecting the end of the object or mark, which is comprised of a light projector and a corresponding light projector.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Embodiment of the Invention FIG. 1 is a diagram showing a main part of a specific length mark detection apparatus which is an embodiment of the invention. In the figure, FAl l FA
S I FBm and do B1 indicate the light emitting/receiving sections arranged along the moving direction of the specific length mark (represented by arrow A), and each light emitting/receiving section is connected to the light emitting diode. An illumination optical fiber that guides light is provided opposite to the illumination optical fiber, and receives transmitted light from a moving object (for example, a transparent sheet) that bears the specific length mark, and transmits it to a phototransistor. It is cut out from the optical fiber for guiding and receiving light. Note that each of the optical fibers may be composed of a single optical fiber, or may be composed of a so-called optical fiber bundle in which a plurality of optical fibers are focused. Furthermore, the light projecting section consisting of the light emitting diode and the illumination optical fiber may be provided corresponding to each of the light receiving sections, and the light of one light emitting diode (light source) may be transmitted through a plurality of illumination optical fibers. The light may be guided to the light receiving section. In the following description, an example will be described in which each of the light receiving sections is provided with a light emitting diode and the light emitting diode is guided to each of the light emitting and receiving sections using a single optical fiber.

The optical fibers are arranged as follows. That is, the optical fiber FAX and the optical fiber FAi form a pair, and the optical fiber FBS and the optical fiber FB1 form a pair, and these are arranged from left to right in the figure along the moving direction of the specific length mark. In the specific length mark detection device composed of the pair of light 7 eyeper 2 silks, the optical fibers (FAl, FB When the optical fibers (F, . . . , F□) do not detect light (the specific length mark is present), it is recognized that the end of the specific length mark exists between them. In general,
It is necessary to determine the distance between the two optical fibers in consideration of reading errors and margins.

Generally, by setting the midpoint of these two optical fibers as the mark detection point and setting the distance between the mark detection points of the two sets of optical fibers equal to the length of the specific length mark, both ends of the specific length mark are detected. This makes it possible to detect the presence of a specific length mark and the direction of its movement.

Determining the position of the optical fiber in a strict sense is performed by the method described below.

That is, there is an error between the center of each optical fiber and the mark detection point of the optical fiber due to variations in the setting conditions of the light intensity variation circuit. The error for each optical fiber is as shown in Fig. 1.
, qAI l '[A1 + qBB and qB□. Generally, since the same optical fiber is used under the same conditions, these values will be approximately equal.

Here, the length of the specific length mark that is the object to be detected is 1 m.
Then, the installation position of each optical fiber can be determined as follows, taking into consideration the error in the length of the specific length mark.

7, -Ql2)AB-qAl-qBB
... (1)〈 Noe + QB-I AA + l J, ! l + l
n n + q A + qBI ... (2)
Nomu〉 qAI + qA island
...(3)! . >q, engineering +q□
...(4) Here, t, -Q, : Lower limit value of the length of the specific length mark (Ql 0) tfn+ Q, : Upper limit value of the length of the specific length mark (
Q, and 0) 114 'Optical fiber FA and same F
Distance with Al 'AB' Distance between optical fiber FAs and same F□ 'BB' Distance between optical fiber F□ and same F
Optical fiber F according to the distance from Bl to Equation (1). Same as F□
The distance between the optical fiber FA and the optical fiber FB can be determined by equation (2). Optical fiber F
The positional relationship between 4. and the same FAll, or the relationship between the optical fiber F Since it is desirable to obtain outputs having substantially the same relationship, the positional relationship of these optical fibers is determined by placing them at symmetrical positions. In addition,
In FIG. 1, 0□0, 0A, 0□ and Oml indicate the center positions of the optical fibers F111, FAI, F□ and FBl, respectively.

Using the optical fiber arranged as described above, the optical fluctuations caused by the glazed marks on the moving object are received by a transmission method, which is guided to a phototransistor and converted into an electrical signal. Detect only marks. That is, the four optical fibers FA1. FAQ,
The light received by F□ and FBl is guided to a phototransistor, and after being converted from an optical signal to an electrical signal,
The signal is amplified by a transistor, an operational amplifier, etc., and is further waveform-shaped by a comparator, etc. as necessary, and converted into an electrical signal level that is easy to process. FIG. 2 shows an example of the electrical signal waveform obtained as a result.

Figure 2 shows a situation in which the specific length mark is detected when a moving object moves from left to right in Figure 1 (this is referred to as the "positive direction"), and the horizontal axis represents time. It shows. In addition, in Figure 2, when a mark is detected,
The output of each optical fiber light-receiving element is assumed to indicate the L'' level.The output of each optical fiber light-receiving element arranged as described above is as shown in FIG. is not detected, and the optical fibers FA2 and FB detect the mark, so that the specific length mark is detected.

In addition, in FIG. 2, the specific length mark detection signal is shown at the °°H'' level.

In order to detect the above-mentioned specific length mark, it is necessary to secure the minimum necessary times of ■, ■, and ■ shown in Fig. 2, and for this, the moving speed of the moving object and each optical fiber Needless to say, it is necessary to consider the position of the receiver and the responsiveness of the receiver circuit.

As a circuit that separately outputs the forward direction pulse and the reverse direction pulse from the four-phase Taka pulse, first, two D-type flip-flops are used, and one of them is clocked with the signal of the optical fiber F□. It is possible to use a circuit that outputs the state of the optical 7 eyeper FB1 as a forward direction pulse as a clock, and outputs the state of the optical fiber FAI as a reverse direction pulse using the signal of the optical fiber FAsl as a clock.

In the above embodiment, a set of light emitters and receivers was used, but in order to simplify the light receiving circuit and the logic circuit, the optical fibers FA□ and FB0 were guided to the same light receiving element, and the sum of these light amounts was detected. Alternatively, it is also possible to similarly construct the optical fibers F and F□ and guide them to the same light-receiving element for processing. When the moving direction of the moving object is constant, the optical fiber F□ and FIll are guided to the same light receiving element, and the optical fiber FA.

The specific length mark can be detected by guiding the same F0 to another same light receiving element and processing the signals obtained by these two light receiving elements.

Further, in the above embodiment, an example was shown in which marks on a moving object are detected by a transmission method, but detection may also be performed by a reflection method, in which case, as shown in FIG.
It is preferable to arrange and use reading segments 3 formed by arranging illumination optical fibers 2 around the light-receiving optical fiber 1.

The optical reading method and device of the present invention include, for example,
For example, when projection film is marked with specific length marks at regular intervals, the number of marks is counted to determine the number of frames to be projected, and the feed is controlled based on this in order to project any frame on the film. It is particularly effective for

Effects of the Invention As described above, according to the present invention, in an optical reader that reads the presence of a moving object or mark having a specific length and the direction of movement thereof, two objects are provided at a distance corresponding to the specific length. The apparatus is configured to read the presence of the object or mark having the specified length and the direction of its movement from the output of the means for detecting the end of the object or mark, each consisting of two sets of light receiving sections and corresponding light projecting sections. Therefore, it is now possible to reliably read moving objects or marks with a specific length, which was previously impossible, and it is particularly effective in that it can be applied to relatively small-sized marks of a specific length. is to be a wife.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the main parts of a specific length mark detection device that is an embodiment of the present invention, Fig. 2 is a signal waveform diagram showing an example of detection results, and Fig. 3 is a diagram showing a signal waveform diagram suitable for using a reflection method. FIG. 2 is a diagram showing an outline of the configuration of a light emitting/receiving element. FAl, FAffi, FB□, F□: Optical fiber,
1: Optical fiber for light reception, 28 Optical fiber for illumination, 3
:Read segment. Figure 1 Figure 3 3 Procedural amendment (voluntary) 1 Indication of the case 1988 Patent Application No. 104409 2 Title of the invention Optical reading method and device 3 Person making the amendment Relationship to the case Patent applicant 4. Agent (1g Address: 1-18-15-7, Nishi-Shinjuku, Shinjuku-ku, Tokyo @I Contents of the amendment As per attached sheet (1) Formula with formula (1) on page 0, lines 18 and 19 of the specification ,
That is, r/m-Q1≧'AB "A□-qB□...0
)'m+Q2≦'AA"',+'BB 1qAl +
qBl...■'' is corrected as follows. r/m-Q1≧lAB+qA□+qB□・・・・・・(1
)' m +Q 2≦'AA"AB"BB-qkl"B
1...' or more

Claims (1)

[Claims] (1) In an optical reading method for reading the presence and direction of movement of a moving object or mark having a specific length, two sets of light-receiving units are provided, each separated by a distance corresponding to the specific length; From the output of the means for detecting the edge of the object or mark consisting of the corresponding light projector,
When one of the two sets of end detecting means detects the leading end of the object or mark, and the other end detecting means detects the rear end of the object or mark, the specific length is determined. An optical reading method characterized by reading the presence of an object or mark and its direction of movement. ) In an optical reading device for reading the presence of a moving object or mark having a specific length and the direction of its movement,
An optical reading device comprising a pair of optical fibers or a bundle of optical fibers, and a detection section for optically detecting the end of the object or mark is arranged at a distance corresponding to the specific length.