JP3800455B2 - Reflective optical coupling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a light emitting element and a light receiving element arranged in parallel, and detects the object by receiving the reflected light when the light emitted from the light emitting element is reflected by the object (detected body) by the light receiving element. More particularly, the present invention relates to a reflective optical coupling device with a condensing lens whose detection range is limited by a condensing lens.
[0002]
[Prior art]
As a reflection type optical sensor, there is a reflection type optical coupling device called a reflection type photo interrupter. This reflection type optical coupling device is used as a non-contact sensor that detects various objects that are detection objects in a non-contact state, and among them, a reflection type with a condensing lens whose detection range is limited by a condensing lens The optical coupling device is mainly used for detecting paper in a paper transport system such as a copying machine or a printer.
[0003]
An example of a conventional reflection type optical coupling device provided with a condensing lens is shown in FIG. 4, and the structure of the condensing lens used in the reflection type coupling device is shown in FIGS. An example of use of the reflection type coupling device is shown in FIG.
[0004]
The reflective optical coupling device shown in FIG. 4 includes a body 10 made of a light-shielding resin, a light emitting element 20a and a light receiving element 20b enclosed in the body 10, and a front side of the light emitting element 20a and the light receiving element 20b (see FIG. The cover 40 is located on the upper side and is fitted in the body 10.
[0005]
The light emitting element 20a and the light receiving element 20b have a structure in which a light emitting diode and a photodiode are mounted on a frame 21 shared between them, and these are enclosed in resin bodies 23a and 23b made of a translucent resin, respectively. It has become.
[0006]
The cover 40 is made of a translucent resin. The cover 40 is formed with condensing lens portions 41a and 41b located on the front sides of the light emitting element 20a and the light receiving element 20b, respectively. As shown in FIGS. 5 and 6, the condensing lens portions 41a and 41b are convex lenses in which the front-side surfaces 42a and 42b protrude to the front side, and the directions in which the respective optical axes intersect on the front side. It is inclined to.
[0007]
And between the resin body 23a on the light emitting element 20a side and the resin body 23b on the light receiving element 20b side, and between the condensing lens part 41a on the light emitting element 20a side and the condensing lens part 41b on the light receiving element 20b side, In either case, light is shielded by a part of the body 10 made of light-shielding resin.
[0008]
The light emitted from the light emitting element 20a is condensed by the condensing lens portion 41a of the cover 40 and is irradiated to the front side. When the detected object 50 exists in front of the irradiation direction, the irradiated light is reflected by the detected object 50. The reflected light is condensed by the condensing lens portion 41b of the cover 40, enters the light receiving element 20b, is photoelectrically converted by the light receiving element 20b, and is output. And the presence or absence of the to-be-detected body 50 is optically non-contact detected by this output electric signal.
[0009]
As described above, the reflection type optical coupling device in which each light beam of the irradiation light and the reflected light is limited by the condensing lens and the detection range is limited, as described above, is mainly used for detection of paper in a paper conveyance system such as a copying machine or a printer. Is used.
[0010]
FIG. 7 shows an example of this paper detection system. In this paper detection system, when a paper as the detected body 50 is conveyed in a gap 80 (usually 2 to 4 mm) formed between the horizontal guide plates 60 and 70 disposed opposite to each other, The sheet is detected by the above-described reflection type optical coupling device with a condensing lens disposed below the guide plates 60 and 70. In order to detect this sheet, the guide plates 60 and 70 are provided with punch holes 61 and 71 located on the front side of the reflective optical coupling device.
[0011]
At this time, if the diameters of the punched holes 61 and 71 are large, the paper is easily caught in these holes, which causes a paper jam. For this reason, the diameters of the punched holes 61 and 71 are limited to about 10 mm.
[0012]
Under such circumstances, when the light beams of the irradiation light and the reflected light in the reflection type optical coupling device are large, the light hits the portions around the holes 61 and 71 of the guide plates 60 and 70, and unnecessary reflected light. Is detected. As a result, the S / N ratio obtained due to the presence or absence of the paper is lowered, and in the worst case, the paper is erroneously detected by the reflected light from the periphery of the punched holes 61 and 71 even in the absence of the paper. End up.
[0013]
For this reason, a reflection type optical coupling device with a condensing lens unit that restricts the detection range by condensing each light beam of irradiation light and reflected light by a condensing lens for detecting paper in a paper conveyance system such as a copying machine or a printer. Is used.
[0014]
[Problems to be solved by the invention]
However, the conventional reflective optical coupling device with a condensing lens has the following problems.
[0015]
In the paper detection system as shown in FIG. 7, every time the paper passes through the gap 80 formed between the guide plates 60 and 70, the amount of the paper is small, but the hole 61 in the lower guide plate 60 is used. Paper powder falls from the top. This paper dust is deposited on the cover 40 of the reflective optical coupling device disposed below, and covers the condenser lens portions 41a and 41b, thereby closing the light entrance / exit route. For this reason, a cleaning operation for periodically wiping the front surface of the cover 40 by a maintenance service or the like is performed.
[0016]
This cleaning operation is simpler and more reliable as the front surface of the cover 40 is flatter. However, in the conventional reflection type optical coupling device, the condensing lens portions 41a and 41b formed on the cover 40 are provided. Each of the front-side surfaces 42a and 42b is a convex lens protruding to the front side, and therefore there are many irregularities on the front-side surface of the cover 40. For this reason, there existed a problem that workability | operativity of cleaning work was bad and confirmation of a cleaning state was not easy.
[0017]
The present invention solves the above-described conventional problems, and an object of the present invention is to provide a reflective optical coupling device that can easily and reliably clean the lens portion even though it has a condenser lens. It is to provide.
[0018]
[Means for Solving the Problems]
The reflective optical coupling device of the present invention includes a light emitting element and a light receiving element that are arranged below a guide plate in a paper conveyance system of a copying machine, a printer, and the like, and are arranged in parallel with a light shielding member interposed therebetween. The light receiving element receives reflected light that is irradiated and reflected by the paper conveyed on the guide plate through a hole provided in the guide plate, thereby allowing the paper to be conveyed above the guide plate. In the reflective optical coupling device for detecting the presence or absence, a cover made of a light-transmitting material on which the paper powder dropped due to the passage of the paper is deposited on the front side of the light emitting element and the light receiving element is provided. A slit for fitting a light shielding member is provided, and a first condensing lens separated by the slit is formed on both sides of the slit facing the light emitting element and the light receiving element on the rear surface side of the cover. Each of the first condensing lens portion and the second condensing lens portion, and the front-side surfaces of the first condensing lens portion and the second condensing lens portion are flat surfaces, respectively. The light condensing lens portion and the surface of the second light condensing lens portion on the light emitting element side and the light receiving element side protrude in a spherical shape toward the light emitting element side and the light receiving element side, respectively. The first condensing lens unit and the second condensing lens unit and the second condensing lens unit intersect each other on the front side of the cover without being refracted. 2 and the light emitting element side surface and the light receiving element side surface of the condensing lens part are inclined toward the slit side, and the light emitting element and the light receiving element are on the same frame. Mounted on each from translucent resin Each of the resin bodies is fitted in a flat base portion of a body made of a light-shielding resin, and the body protrudes upward from the base portion. A recess for fitting the cover is provided in the projection, and an opening is provided on the bottom surface of the recess to communicate with the light emitting element and the light receiving element in the recess. A protrusion protruding upward is provided between the openings , and the protrusion constitutes the light shielding member , and the first condensing lens part and the second condensing lens part are formed by the protrusion. It is characterized by being shielded from light , thereby achieving the above object.
[0019]
The operation of the present invention will be described below.
[0020]
In the reflection type optical coupling device of the present invention, each condensing lens portion formed on the cover corresponding to each of the light emitting element and the light receiving element is formed so as to protrude to the rear surface side of the cover. The surface on the front side is flattened, and the unevenness of the surface is reduced. For this reason, when cleaning the surface of the front side of the cover, the cleaning work is simplified. Moreover, the surface is easy to see, and the cleaning state of the surface can be easily confirmed. These improve the maintainability.
[0021]
In addition, about a condensing function, it is not different from the case where the surface of the front side of each condensing lens part is protruded to the front side.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0023]
1 to 3 show an embodiment of a reflection type optical coupling device of the present invention. As shown in FIG. 1, the reflective optical coupling device of the present embodiment includes a body 10 made of a light-shielding resin, a light emitting element 20 a and a light receiving element 20 b enclosed in the body 10, and positions on the front side thereof. And a cover 30 fitted in the body 10.
[0024]
This reflective optical coupling device is different from the conventional reflective optical coupling device shown in FIGS. 4 to 6 in the cover 30. Hereinafter, the structure of each part is demonstrated centering on the part relevant to the cover 30. FIG.
[0025]
The body 10 made of light-shielding resin has a flat base portion 11 and a convex portion 12 protruding upward from the center portion thereof. On the upper surface of the convex portion 12, a rectangular concave portion 13 into which the cover 30 is fitted is provided. Openings 14a and 14b are provided on the bottom surface of the recess 13 in order to make the recess 13 optically communicate with the lower light emitting element 20a and light receiving element 20b. Further, a protrusion 15 is provided between the openings 14a and 14b.
[0026]
The light emitting element 20a and the light receiving element 20b are enclosed in the central portion of the base portion 11 of the body 10 and face the recess 13 through the openings 14a and 14b, respectively. As described above, the structure of the light emitting element 20a and the light receiving element 20b is such that the light emitting diode and the photodiode are mounted on the frame 21 shared between them, and each chip is made of resin bodies 23a and 23b made of a translucent resin. Each is enclosed inside. The resin bodies 23a and 23b are shielded from light by the forming material (light-shielding resin) of the body 10 filled therebetween.
[0027]
The cover 30 is a rectangular flat plate integrally formed product using a translucent resin, and is inserted into the concave portion 13 of the cover 30 from the upper side (front side). As shown in FIGS. 2 and 3, the cover 30 has a slit 34 to which the projection 15 of the body 10 fits in the center portion, and is located on both sides of the slit 34 and includes the condenser lens portions 31 a and 31 b. Have.
[0028]
The condensing lens portions 31a and 31b are positioned on the front sides of the light emitting element 20a and the light receiving element 20b, respectively, and are inclined in directions in which the respective optical axes intersect on the front side. The condensing lens portion 31a on the light emitting element 20a side is a convex lens in which the front surface 32a is a flat surface and the element side surface 3a protrudes spherically toward the element. The surfaces 32a and 33a of the condenser lens portion 31a are inclined toward the slit 34 along with the inclination of the optical axis described above. Similarly, the condensing lens portion 31b on the side of the light receiving body 20b is a convex lens in which the front surface 32b is a flat surface, and the element side surface 33b protrudes spherically toward the element side, and the surfaces 32b and 33b are It is inclined toward the slit 34 along with the inclination of the optical axis described above.
[0029]
Further, the condenser lens portions 31a and 31b are shielded from light by fitting the projection 15 of the body 10 into the slit 34 therebetween.
[0030]
The operation of the reflection type optical coupling device having such a configuration will be described.
[0031]
The light emitted from the light emitting element 20a is condensed by the condensing lens part 31a of the cover 30 and irradiated to the front side. When the detected object 50 exists in front of the irradiation direction, the irradiated light is reflected by the detected object 50. The reflected light is condensed by the condensing lens portion 31b of the cover 30 and is incident on the light receiving element 20b, and is photoelectrically converted in the same manner as the above-described conventional example, thereby detecting the presence or absence of the detection target 50 in a non-contact state. It has become so.
[0032]
This reflection type optical coupling device is used for detecting a sheet conveyed upward in a sheet conveyance system such as a copying machine or a printer (see FIG. 7). In that case, every time the paper which is the detection object 50 passes above the reflection type optical coupling device, although it is a small amount, paper dust falls. The fallen paper dust accumulates on the cover 30 of the reflective optical coupling device disposed below, and covers the condensing lens portions 31a and 31b, thereby closing the light entrance / exit route. For this reason, a cleaning operation for periodically wiping the front surface of the cover 30 is performed by a maintenance service or the like. Is a convex lens that protrudes toward the element side, and the front-side surfaces 32a and 32b are flat, so that there are few irregularities on the front-side surface of the cover 30. For this reason, when the surface of the front side of the cover 30 is cleaned, the cleaning work is simplified. Moreover, the surface is easy to see, and the cleaning state of the surface can be easily confirmed. These improve the maintainability.
[0033]
【The invention's effect】
According to the above reflection type optical coupling device of the present invention, each condensing lens portion formed on the cover corresponding to each of the light emitting element and the light receiving element is formed in a state of protruding to the rear surface side of the cover. Since the surface on the front side of the cover is flattened and unevenness on the surface on the front side of the cover is reduced, the cleaning operation is simplified when cleaning the surface on the front side of the cover. Moreover, the surface is easy to see, and the cleaning state of the surface can be easily confirmed. Therefore, excellent maintainability is ensured despite the fact that the condenser lens is attached.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a reflective optical coupling device of the present invention.
FIG. 2 is a plan view of a cover of the reflection type optical coupling device of the present invention.
FIG. 3 is a vertical side view of a cover of the reflective optical coupling device of the present invention.
FIG. 4 is a vertical side view of a conventional reflective optical coupling device.
FIG. 5 is a plan view of a cover of a conventional reflective optical coupling device.
FIG. 6 is a longitudinal side view of a cover of a conventional reflective optical coupling device.
FIG. 7 is a vertical side view of a paper detection system using a reflective optical coupling device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Body 20a Light emitting element 20b Light receiving element 30 Cover 31a, 31b Condensing lens part

Claims (1)

A light emitting element and a light receiving element that are arranged below a guide plate in a paper conveyance system of a copying machine, a printer, and the like, and are arranged in parallel with a light shielding member interposed therebetween, are irradiated from the light emitting element, and are provided on the guide plate In a reflective optical coupling device that detects the presence or absence of a sheet conveyed above the guide plate by receiving reflected light reflected by the sheet conveyed on the guide plate through a punched hole by the light receiving element. ,
The light emitting element and the light receiving element are provided with a cover made of a translucent material on which the paper powder dropped by the passage of the paper is deposited on the front side of the light receiving element, and the cover is provided with a slit into which the light shielding member is fitted. And
A first condensing lens portion and a second condensing lens portion separated by the slit are respectively provided on both side portions of the slit facing the light emitting element and the light receiving element on the rear surface side of the cover. And
Front side surfaces of the first condensing lens part and the second condensing lens part are flat surfaces, respectively, and the first condensing lens part and the second condensing lens part Surfaces of the light emitting element side and the light receiving element side protrude in a spherical shape toward the light emitting element side and the light receiving element side, respectively, and the first condensing lens unit and the second condensing lens unit Front surfaces of the first condensing lens unit and the second condensing lens unit, the light emitting element side, and the light converging lens unit so that the optical axes intersect with each other on the front surface side of the cover without being refracted. Each of the light receiving element side surfaces is inclined toward the slit side,
The light emitting element and the light receiving element are mounted on the same frame and sealed in a resin body made of a translucent resin,
Each of the resin bodies is fitted into a flat base portion in a body made of a light shielding resin,
The body has a convex portion protruding upward from the base portion, and a concave portion into which the cover is fitted is provided in the convex portion, and the light emitting element and the light receiving portion are disposed in the concave portion on the bottom surface of the concave portion. An opening communicating with each of the elements is provided, and a protrusion protruding upward is provided between the openings.
The reflection type optical coupling device , wherein the projection constitutes the light shielding member , and the projection is configured to shield the first condenser lens portion and the second condenser lens portion .

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