JP4228531B2 - Medium detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medium detection apparatus that detects a medium using light, and more particularly to a medium detection apparatus with improved reliability as an apparatus.
[0002]
[Prior art]
Conventionally, the medium detecting device utilizing light emitting element and a light receiving element are then arranged in pairs toward each other across the conveying path of the medium. If the light emitted from the light emitting element is not blocked by the medium, it is received by the light receiving element. When the light from the light emitting element is blocked by the medium transported through the transport path, it is not received by the light receiving element. Therefore, it is considered that the medium is detected by not receiving light by the light receiving element.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional medium detection device, if either the light receiving element or the light emitting element cannot operate normally for some reason, such as failure, dirt, life, etc., the entire apparatus cannot operate. was there.
[0004]
In addition, the conventional medium detection apparatus only detects the presence or absence of a medium, and does not detect the conveyance speed and conveyance direction of the medium at the same time, and cannot be used for various applications. there were.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a medium for detecting a medium by arranging that the light emitted from the light emitting element is received by the light receiving element and detecting that the medium blocks the light emitted from the light emitting element. In the detection apparatus, an optical path having a light incident end for receiving light from the light emitting element, a light exit end for emitting the incident light to the light receiving element, and one light emitting element are necessary for medium detection. A light emitting element switching means for switching to another light emitting element when an output of a certain degree cannot be obtained, the light emitting element is provided more than the light receiving element, and the light path body includes the light emitting element and the light emitting element. A light incident end and a light exit end are provided so as to face each of the light receiving elements, and light that has entered the light path from all the light incident ends exits from one light exit end. It is characterized by.
According to another aspect of the present invention, there is provided a medium detection device that detects a medium by detecting that the light emitted from the light emitting element is received by the light receiving element, and that the medium blocks the light emitted from the light emitting element. An optical path body having a light incident end for receiving light from the element and a light output end for emitting the incident light to the light receiving element, and an output necessary for detecting the medium by one light receiving element. A light receiving element switching means for switching to another light receiving element when it is no longer possible, and more light receiving elements are provided than the light emitting elements, and the light path body is provided in each of the light emitting elements and the light receiving elements. A light incident end portion and a light exit end portion are provided so as to face each other, and light that has entered the light path body from one light incident end portion passes through the light path body and from all the light exit end portions. It is characterized by emitting light.
According to another aspect of the present invention, there is provided a medium detection device that detects a medium by detecting that the light emitted from the light emitting element is received by the light receiving element, and that the medium blocks the light emitted from the light emitting element. A light path body including a light incident end portion for receiving light from the element and a light exit end portion for emitting the incident light to the light receiving element, and a plurality of the light receiving elements and the light emitting elements are provided, respectively. The light path body is provided with a plurality of light incident end portions and light exit end portions so as to face the light emitting element and the light receiving element, respectively, and light is incident on the light path body from one light incident end portion. The light that has passed through the light path exits from all light exit ends, and light that enters the light path from all light entrance ends exits from one light exit end. Is .
[0006]
According to the present invention having the above-described configuration, when the light-emitting element or the light-receiving element cannot obtain an output necessary for medium detection due to a failure or contamination, the element that has not been used until then is used. Thus, an output necessary for medium detection can be obtained, and it is not necessary to stop the apparatus, thereby improving the reliability of the apparatus.
[0007]
In addition, a plurality of light emitting elements are disposed, and a plurality of light incident end portions of the light path body are provided to face the plurality of light emitting elements, respectively, so that the medium is conveyed between the light path and the light emitting elements. The light emission amounts of the light emitting elements are made different from each other. With this configuration, it is possible to detect the conveyance speed and the conveyance direction of the medium.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing a light path in an optical path in the first embodiment, and FIG. 3 is a circuit block of the first embodiment. FIG.
[0009]
1 and 2, the medium detection device 1 according to the first embodiment is provided with two light emitting elements 2, 3 and one light receiving element 4, and the light emitting elements 2, 3 and the light receiving element 4 An optical path body 5 is provided between them. The light emitting elements 2 and 3 are composed of, for example, light emitting diodes or laser diodes, and the light receiving element 4 is composed of, for example, a phototransistor or a photodiode. The light path body 5 is made of a light-transmitting member, such as a transparent plastic resin, and has light incident ends 6 and 7 facing the light emitting elements 2 and 3, and a light emitting end 8 facing the light receiving element 4. And light paths 9, 10, 11, 12 connecting the respective ends.
[0010]
Between the light path 9 and the light path 10, a reflection portion 15 that forms 45 degrees with respect to the light traveling direction is formed, and between the light path 11 and the light path 12, the light is reflected at a right angle. A portion 16 is formed. A transport path 14 for the medium 13 is provided between the light path body 5 and the light receiving element 4. The light path 10 is a common path through which both the light from the light emitting element 2 and the light from the light emitting element 3 pass.
[0011]
In FIG. 3, a light emitting circuit 22 is connected to a central processing unit (CPU) 21, and light emitting elements 2 and 3 are connected to the light emitting circuit 22. The CPU 21 causes the light emitting elements 2 and 3 to emit light via the light emitting circuit 22. The CPU 21 is connected to an analog / digital (A / D) converter 24, and the light receiving element 4 is connected to the A / D converter 24 via a light receiving circuit 25.
[0012]
Next, the operation of the first embodiment will be described. First, the CPU 21 causes the light emitting element 2 to emit light via the light emitting circuit 22. Usually, the medium 13 is detected by causing the light emitting element 2 to emit light. Light emitted from the light emitting element 2 enters the light path body 5 from the light incident end 6, travels straight through the light path 9 and the light path 10, exits from the light exit end 8, crosses the transport path 14, and the light receiving element 4 is received.
[0013]
At this time, when the medium 13 is transported through the transport path 14 and the medium 13 reaches between the light exit end 8 and the light receiving element 4, the light receiving element 4 cannot receive the light from the light exit end 8. By detecting this, the CPU 21 determines that the medium 13 has been transported between the light exit end 8 and the light receiving element 4.
[0014]
When the light emitting element 2 cannot obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 21 switches the light emitting element and causes the light emitting element 3 to emit light. As a result, the medium 13 can be continuously detected.
[0015]
The light emitted from the light emitting element 3 enters the light path body 5 from the light incident end 7, passes through the light path 11, is reflected by the reflecting section 16, and enters the light path 12. The light that has entered the light path 12 is further reflected by the reflecting portion 15, enters the light path 10, exits the light exit end 8, and is received by the light receiving element 4 across the transport path 14. Thereby, the medium 13 conveyed in the conveyance path 14 is detected.
[0016]
As described above, according to the first embodiment, when the light-emitting element 2 cannot obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 21 switches the light-emitting element to emit light. The element 3 is caused to emit light. Accordingly, the medium 13 can be continuously detected without switching the light receiving element 4, and the reliability of the medium detecting device can be improved. Of course, either one of the light emitting elements 2 and 3 may be used at the normal time.
[0017]
Next, a second embodiment will be described. FIG. 4 is a configuration diagram of the second embodiment of the present invention, FIG. 5 is an explanatory diagram showing the path of light in the optical path in the second embodiment, and FIG. 6 is a circuit block of the second embodiment. FIG.
[0018]
4 and 5, the medium detection device 31 according to the second embodiment includes one light emitting element 32 and two light receiving elements 33 and 34, and the light emitting element 32 and the light receiving elements 33 and 34. An optical path body 35 is provided between them. The light emitting element 32 is composed of, for example, a light emitting diode or a laser diode, and the light receiving elements 33 and 34 are composed of, for example, a phototransistor or a photodiode. The light path body 35 is made of a light transmitting member, such as a transparent plastic resin, and has a light incident end portion 36 facing the light emitting element 32 and light emitting end portions 37 and 38 facing the light receiving elements 33 and 34, respectively. And light paths 39, 40, 41, 42 connecting the respective ends.
[0019]
Between the light path 39 and the light path 40, a reflection portion 45 that forms 45 degrees with respect to the traveling direction of the light is formed, and between the light path 41 and the light path 42, the light is reflected at a right angle. A portion 46 is formed. A transport path 14 for the medium 13 is provided between the light path body 35 and the light emitting element 32. The light path 39 is a common path through which both the light received by the light receiving element 33 and the light received by the light receiving element 34 pass.
[0020]
In FIG. 6, a light emitting circuit 52 is connected to a central processing unit (CPU) 51, and a light emitting element 32 is connected to the light emitting circuit 52. The CPU 51 causes the light emitting element 32 to emit light via the light emitting circuit 52. The CPU 51 is connected to an analog / digital (A / D) converter 54, and light receiving elements 33 and 34 are connected to the A / D converter 54 via a light receiving circuit 55.
[0021]
Next, the operation of the second embodiment will be described. First, the CPU 51 causes the light emitting element 32 to emit light via the light emitting circuit 52. The light emitted from the light emitting element 32 first crosses the transport path 14, enters the light path body 35 from the light incident end 36, travels straight through the light path 39 and the light path 40, and exits from the light exit end 37. Light is received by the light receiving element 33 . Usually, the medium 13 is detected by receiving light by the light receiving element 33.
[0022]
When the medium 13 is transported through the transport path 14 and the medium 13 reaches between the light incident end 36 and the light emitting element 32, the light emitted from the light emitting element 32 does not enter the light path body 35, and the light receiving element 33. Cannot receive light. By detecting this, the CPU 51 determines that the medium 13 has been conveyed between the light incident end 36 and the light emitting element 32.
[0023]
When the light receiving element 33 is unable to obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 51 switches the light receiving element so that the light receiving element 34 receives light. As a result, the medium 13 can be continuously detected.
[0024]
When the light receiving element is switched, the light emitted from the light emitting element 32 first crosses the transport path 14 and enters the light path body 35 from the light incident end 36, passes through the light path 39 and is reflected by the reflecting section 45, Enter the light path 41. The light that has entered the optical path 41 is further reflected by the reflecting section 46, enters the optical path 42, exits the light exit end 38, and is received by the light receiving element 34 . Thereby, the medium 13 conveyed in the conveyance path 14 is detected.
[0025]
As described above, according to the second embodiment, when the light receiving element 33 cannot obtain an output necessary for medium detection due to failure, dirt, or a life, the CPU 51 switches the light receiving element to receive light. The element 34 receives light. As a result, the medium 13 can be continuously detected without switching the light emitting element 32, and the reliability of the medium detecting apparatus can be improved. Of course, either one of the light receiving elements 33 and 34 may be used in a normal state.
[0026]
Next, a third embodiment will be described. FIG. 7 is a configuration diagram of the third embodiment of the present invention, FIG. 8 is a circuit block diagram of the third embodiment, and FIG. 9 is a perspective view showing an optical path body of the third embodiment.
[0027]
7 and 9, the medium detection device 61 according to the third embodiment is provided with two light emitting elements 62 and 63 and two light receiving elements 64 and 65, and the light emitting elements 62 and 63 and the light receiving element. An optical path member 66 is provided between the light guide members 64 and 65. The light emitting elements 62 and 63 are composed of, for example, light emitting diodes or laser diodes, and the light receiving elements 64 and 65 are composed of, for example, phototransistors or photodiodes. The light path body 66 is made of a member that transmits light, such as a transparent plastic resin. A transport path 14 for the medium 13 is provided between the light path body 66 and the light receiving elements 64 and 65.
[0028]
The light path body 66 has light incident end portions 67 and 68 facing the light emitting elements 62 and 63, and light exit end portions 69 and 70 facing the light receiving elements 64 and 65, respectively, and connects the respective end portions. It has light paths 71, 72, 73, 74 and a light path 75 located in the middle. Reflecting portions 76 and 77 forming 45 degrees with respect to the light traveling direction are formed between the light path 71 and the light path 72, and light is reflected at right angles between the light path 73 and the light path 74. Reflecting portions 78 and 79 are formed.
[0029]
In FIG. 8, a light emitting circuit 82 is connected to a central processing unit (CPU) 81, and light emitting elements 62 and 63 are connected to the light emitting circuit 82. The CPU 81 causes the light emitting elements 62 and 63 to emit light via the light emitting circuit 82. The CPU 81 is connected to an analog / digital (A / D) converter 84, and light receiving elements 64 and 65 are connected to the A / D converter 84 via a light receiving circuit 85.
[0030]
Next, the operation of the third embodiment will be described. First, the CPU 81 causes the light emitting element 62 to emit light via the light emitting circuit 82. The light emitted from the light emitting element 62 enters the light path body 66 from the light incident end 67, travels straight through the light path 71 and the light path 72, exits from the light output end 69, crosses the transport path 14, and receives light. Light is received by the element 64. Usually, the medium 13 is detected by receiving light emitted by the light emitting element 62 by the light receiving element 64.
[0031]
When the medium 13 is transported through the transport path 14 and the medium 13 reaches between the light exit end 69 and the light receiving element 64, the light from the light path body 66 is not received by the light receiving element 64. By detecting this, the CPU 81 determines that the medium 13 has been conveyed between the light exit end 69 and the light receiving element 64.
[0032]
When the light emitting element 62 cannot obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 81 switches the light emitting element and causes the light emitting element 63 to emit light. As a result, the medium 13 can be continuously detected.
[0033]
The light emitted from the light emitting element 63 enters the light path body 66 from the light incident end 68, passes through the light path 73, is reflected by the reflecting portion 78, and enters the light path 75. The light that has entered the light path 75 is further reflected by the reflecting section 77, enters the light path 72, exits the light exit end 69, and is received by the light receiving element 64 across the transport path 14. Thereby, the medium 13 conveyed in the conveyance path 14 is detected.
[0034]
In addition, when the light receiving element 64 cannot obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 81 switches the light receiving element so that the light receiving element 65 receives light. As a result, the medium 13 can be continuously detected.
[0035]
When the light receiving element is switched, the light emitted from the light emitting element 62 enters the light path body 66 from the light incident end 67, passes through the light path 71, is reflected by the reflecting section 76, and enters the light path 75. The light that has entered the light path 75 is further reflected by the reflecting portion 79, enters the light path 74, exits the light exit end 70, and is received by the light receiving element 65 across the transport path 14. Thereby, the medium 13 conveyed in the conveyance path 14 is detected.
[0036]
Further, when switching both the light emitting element and the light receiving element, the CPU 81 outputs light from the light emitting element 63 and causes the light receiving element 65 to receive the light. In this case, the light emitted from the light emitting element 63 enters the light path body 66 from the light incident end 68, travels straight through the light path 73 and the light path 74, exits from the light exit end 70, and crosses the transport path 14. The light receiving element 64 receives the light.
[0037]
As described above, according to the third embodiment, when the light-emitting element 62 or the light-receiving element 64 cannot obtain an output necessary for medium detection due to failure, dirt, or life, the CPU 81 Alternatively, the light receiving element is switched and light is received by another light emitting element or light receiving element. As a result, the medium 13 can be continuously detected, and the reliability of the medium detection apparatus can be improved.
[0038]
Next, a fourth embodiment will be described. FIG. 10 is a configuration diagram of the fourth embodiment, and FIG. 11 is a time chart showing a change in the output of the light receiving element in the fourth embodiment.
[0039]
In FIG. 10, the medium detecting device 91 of the fourth embodiment is provided with two light emitting elements 2 and 3 and one light receiving element 4 as in the first embodiment. 3 and the light receiving element 4 are provided with an optical path body 5. The light path body 5 has light incident ends 6 and 7 that face the light emitting elements 2 and 3, respectively, and a light exit end 8 that faces the light receiving element 4, and light paths 9, 10, which connect the respective ends. 11 and 12. A reflection portion 15 is formed between the light passage 9 and the light passage 10, and a reflection portion 16 is formed between the light passage 11 and the light passage 12. However, a transport path 14 for the medium 13 is provided between the light path body 5 and the light emitting elements 2 and 3.
[0040]
The control system of the fourth embodiment is the same as that of the first embodiment shown in FIG.
[0041]
Next, the operation of the fourth embodiment will be described with reference to FIG. 10, FIG. 11, and FIG. First, the CPU 21 causes both light emitting elements 2 and 3 to emit light via the light emitting circuit 22. Light emitted from the light emitting element 2 enters the light path member 5 from the light input end 6 across the transporting path 14, out of the light egress end 8 straight optical path 9 and the optical path 10, the light receiving Light is received by the element 4. The light emitted from the light emitting element 3 crosses the transport path 14 and enters the light path body 5 from the light incident end 7, passes through the light path 11, is reflected by the reflecting section 16, and enters the light path 12. Light entering the light path 12 is reflected by further reflection portion 15, it enters the optical path 10, out of the light egress end 8 and is received by the light receiving element 4.
[0042]
When the medium 13 does not exist at a position facing the light emitting element 2 or the light emitting element 3, the output of the light receiving element 4 is the highest as indicated by a in FIG. In this case, light emitted from both the light emitting element 2 and the light emitting element 3 is received by the light receiving element 4. As shown in FIG. 10, when the medium 13 is conveyed from the left side and reaches between the light incident end 6 and the light emitting element 2, the light emitted from the light emitting element 2 is blocked, and the light receiving element 4 is directed to the light receiving element 4. Only light from the light enters. Therefore, as indicated by b in FIG. 11, the output of the light receiving element 4 decreases.
[0043]
When the medium 13 is further conveyed and reaches between the light incident end 7 and the light emitting element 3, light from the light emitting element 3 is blocked, and light from the light emitting elements 2 and 3 does not enter the light receiving element 4, As indicated by c in FIG. 11, the output of the light receiving element 4 further decreases. When the medium 13 is further transported and passes between the light incident end 6 and the light emitting element 2, light from the light emitting element 2 enters the light receiving element 4, and as shown by d in FIG. The output of 4 goes up. When the medium 13 is further transported and passes between the light incident end 7 and the light emitting element 3, light from the light emitting element 3 also enters the light receiving element 4, and as shown by a in FIG. The output of 4 goes up further.
[0044]
Since the position of the medium 13 can be detected from the output change of the light receiving element 4 as described above, the conveyance speed of the medium 13 can be calculated by setting the interval between the detection points to a predetermined value. The length of the medium 13 can also be calculated.
[0045]
That is, in FIG. 11, the distance between the light emitting element 2 and the light emitting element 3 is set to a predetermined value, and by measuring the time from the time point when changing from a to b to the time point when changing from b to c, The conveyance speed of the medium 13 can be calculated. Further, for example, by measuring the time from the time point when changing from a to b to the time point when changing from c to d, it is possible to calculate the time that the medium 13 has passed through the light emitting element 2, and from this time and the conveyance speed, The length can be calculated.
[0046]
Further, in the apparatus 91 shown in FIG. 10, by setting the conveyance direction of the medium 13 to a direction orthogonal to the straight line connecting the light emitting element 2 and the light emitting element 3, the degree of inclination (angle) with respect to the conveyance direction of the medium 13 to be conveyed ) Can be detected. The angle of inclination of the medium 13 can be calculated by measuring the time from when one of the light emitting element 2 and the light emitting element 3 first detects the medium 13 until the other detects it.
[0047]
Next, an example in which the medium is detected by changing the outputs (light emission amounts) of the light emitting elements 2 and 3 in the apparatus 91 shown in FIG. The conveyance direction of the medium 13 is as shown in FIG. FIG. 12 shows a time chart showing the output change of the light receiving element in this case. In the example shown in FIG. 12, the light emitting element 2 emits more light than the light emitting element 3.
[0048]
In FIG. 12, a indicates a case where the medium 13 does not exist at a position facing the light emitting element 2 or the light emitting element 3. e indicates a case where the medium 13 exists between the light incident end 6 and the light emitting element 2. c shows the case where the medium 13 exists between the light incident end 6 and the light emitting element 2 and between the light incident end 7 and the light emitting element 3. Further, f indicates a case where the medium 13 does not exist between the light incident end 6 and the light emitting element 2 but exists only between the light incident end 7 and the light emitting element 3. As shown in the figure, the output level for e and the output level for f are different.
[0049]
From the above, when the medium 13 is conveyed in a linear direction connecting the light emitting element 2 and the light emitting element 3, depending on whether the level of e comes first and then f follows, or vice versa, It can be known whether the medium 13 is conveyed in the direction of the arrow, that is, in the direction of arrow A shown in FIG.
[0050]
FIG. 13 is a time chart showing a change in output of the light receiving element when the medium 13 is conveyed in the direction opposite to the arrow A direction shown in FIG. In FIG. 13, f indicates a case where the medium 13 exists only between the light incident end 7 and the light emitting element 3, and e indicates only between the medium 13 between the light incident end 6 and the light emitting element 2. Since the case where it exists exists, it turns out that the medium 13 is conveyed in the reverse direction of the arrow A direction shown in FIG.
[0051]
Further, when the output is different between the light emitting element 2 and the light emitting element 3, the medium 13 to be conveyed is set so that the conveyance direction of the medium 13 is orthogonal to the straight line connecting the light emitting element 2 and the light emitting element 3. It is possible not only to detect the degree of inclination (angle) with respect to the conveyance direction, but also to detect which side is inclined. This can be detected depending on which of the output levels e and f shown in FIG. 12 or 13 is output first.
[0052]
Next, an example will be described in which the medium is detected by making the wavelengths of the light emitting element 2 and the light emitting element 3 different in the apparatus 91 shown in FIG. By making the wavelengths of the light emitting element 2 and the light emitting element 3 different, the transmittance of the medium is different, and the difference between the outputs of the light emitting element 2 and the light emitting element 3 (the amount of light transmitted through the medium) is increased.
[0053]
Therefore, by making the wavelengths of the light emitting element 2 and the light emitting element 3 different, the output levels as shown by e and f in FIGS. 12 and 13 are made different to detect the transport direction and the inclination direction of the medium 13. be able to. Further, by making the light emission amounts of the light emitting element 2 and the light emitting element 3 different and further making the wavelength different, the output of the light receiving element 4 when only passing through the position of the light emitting element 2, and the position of the light emitting element 3 It is possible to further increase the output difference from the output of the light receiving element 4 when only the light passes, and the detection accuracy is improved.
[0054]
As described above, according to the fourth embodiment, both the light emitting element 2 and the light emitting element 3 emit light, and from the output difference of the light receiving element 4 at that time, the conveyance speed of the medium 13, the length of the medium 13, and the medium The degree and direction of the inclination of 13 and the conveyance direction of the medium 13 can be detected, and not only the presence / absence of the medium 13 but also various uses can be used. In addition, when only one of the light emitting element 2 and the light emitting element 3 emits light, the same effect as the first embodiment is obtained.
[0055]
【The invention's effect】
As described above in detail, according to the present invention, when a light emitting element or a light receiving element cannot obtain an output necessary for medium detection due to a failure or contamination, an element that has not been used until then can be obtained. By using it, an output necessary for medium detection can be obtained, and it is not necessary to stop the apparatus, and the reliability of the apparatus can be improved.
[0056]
Further, by utilizing the output difference of the light receiving element when detecting a medium by causing a plurality of light emitting elements to emit light, it can be used not only for the presence / absence of the medium but also for various applications.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment.
FIG. 2 is an explanatory diagram of a light path in the light path in the first embodiment.
FIG. 3 is a circuit block diagram of the first embodiment.
FIG. 4 is a configuration diagram of a second embodiment.
FIG. 5 is an explanatory diagram of a light path in an optical path according to a second embodiment.
FIG. 6 is a circuit block diagram of a second embodiment.
FIG. 7 is a configuration diagram of a third embodiment.
FIG. 8 is a circuit block diagram of a third embodiment.
FIG. 9 is a perspective view showing an optical path body according to a third embodiment.
FIG. 10 is a configuration diagram of a fourth embodiment.
FIG. 11 is a time chart showing an output change of the light receiving element in the fourth embodiment.
FIG. 12 is a time chart showing a change in output of the light receiving element when the output of the light emitting element is changed.
FIG. 13 is a time chart showing a change in output of the light receiving element when the medium is conveyed in the reverse direction.
[Explanation of symbols]
1, 31, 61, 91 Medium detection device 2, 3, 32, 62, 63 Light emitting element 4, 33, 34, 64, 65 Light receiving element 5, 35, 66 Light path body 13 Medium 14 Transport path

Claims (5)

In the medium detection device that detects the medium by arranging that the light emitted from the light emitting element is received by the light receiving element, and detecting that the medium blocks the light emitted from the light emitting element,
A light path body comprising a light incident end for entering light from the light emitting element and a light exit end for emitting the incident light to the light receiving element;
A light-emitting element switching means for switching to another light-emitting element when one light-emitting element cannot obtain an output necessary for medium detection;
More light emitting elements are provided than the light receiving elements,
The light path body is provided with a light incident end and a light exit end so as to face the light emitting element and the light receiving element, respectively.
The medium detection device according to claim 1, wherein light incident on the light path from all light incident ends exits from one light exit end . In the medium detection device that detects the medium by arranging that the light emitted from the light emitting element is received by the light receiving element, and detecting that the medium blocks the light emitted from the light emitting element,
A light path body comprising a light incident end for entering light from the light emitting element and a light exit end for emitting the incident light to the light receiving element;
A light receiving element switching means for switching to another light receiving element when one light receiving element cannot obtain an output necessary for medium detection;
More light receiving elements are provided than the light emitting elements,
The light path body is provided with a light incident end and a light exit end so as to face the light emitting element and the light receiving element, respectively.
The medium detection device according to claim 1, wherein light incident on the light path body from one light incident end passes through the light path and exits from all light exit ends . In the medium detection device that detects the medium by arranging that the light emitted from the light emitting element is received by the light receiving element, and detecting that the medium blocks the light emitted from the light emitting element,
A light path body comprising a light incident end for entering light from the light emitting element and a light exit end for emitting the incident light to the light receiving element;
A plurality of the light receiving elements and the light emitting elements are provided,
The light path body is provided with a plurality of light incident end portions and light exit end portions so as to face the light emitting element and the light receiving element, respectively.
Light that has entered the light path from one light incident end passes through the light path and exits from all the light exit ends, and enters the light path from all light incident ends. A medium detecting device characterized in that light is emitted from one light emitting end . Wherein the plurality of light emitting elements are each emitting different amounts claims 1 to 3 medium detection device according. Wherein the plurality of light emitting elements are mutually different wavelengths claims 1 to 3 medium detection device according.

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