JPS5826436Y2 - Reflective photoelectric switch - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a reflective charging switch.

A reflective optical switch reflects the projected light from the light emitting element with a reflector, detects the reflected light from the reflector with a light receiving element, and amplifies the received light output of this light receiving element with an amplifier circuit.
It drives a switching circuit and controls on/off of controlled devices such as relays, but the light emitting element and light receiving element are arranged in a single case, and the light emitting element inside this case A light projecting hood for guiding the projected light to the outside and a light receiving hood for guiding the reflected light from the reflector to the light receiving element may be provided in the case in correspondence with the light projecting element and the light receiving element, respectively. There is this type of cone-shaped floodlight hood,
When the light-receiving hood is provided inside the case, the hood occupies a large proportion of the case, resulting in poor space efficiency.

This invention was proposed in view of the above, and aims to improve space efficiency within the case of a reflective optical switch, thereby facilitating miniaturization.

In order to achieve this purpose, this invention houses a light emitting element and a light receiving element in a single case, reflects the projected light from the light emitting element with a reflector, and transfers this reflected light to the light receiving element. The light receiving element detects the received light, and the light receiving output of this light receiving element is amplified by the amplifier circuit to drive the switching circuit.
a conical light projecting hood for guiding the projected light from the light projecting element to the outside; and a conical light receiving hood for guiding the reflected light from the reflector to the light receiving element; In the reflective photoelectric switch provided corresponding to the light receiving element,
A side wall of the light emitting hood is removed to form an opening, and the light emitting hood with the side wall removed and the light receiving hood are arranged in parallel to form an integrally formed element holder. The optical axes of the light emitting element and light receiving element fixed to the rear ends of the light emitting hood and the light receiving hood, respectively, are parallel to the printed circuit board on which the plurality of electronic components such as the amplifier circuit and the switching circuit are mounted. The element holder is placed on the printed circuit board as shown in FIG. The present invention is characterized in that some of the plurality of electronic components are arranged near the opening.

According to this invention, since the side wall of the floodlight hood is removed to form an opening, there is no wall thickness of the hood at all in this opening, and the element holder is made smaller by the side wall removed. This frees up space, and by arranging some of the electronic components in that space, the printed circuit board itself becomes smaller, and the reflective photoelectric switch as a whole becomes smaller.

Furthermore, the light-transmitting hood and the light-receiving hood are arranged in parallel and integrally formed to form an element holder, and the emitting element and the light-receiving element are fixed to the rear end of each hood, and the light-emitting element and the light-receiving element are fixed to the rear end of each hood. Since the structure is such that the cover provided with the light and light receiving lenses is engaged, the relative positions of the light emitting element and the light receiving element as well as the relative positions of the light emitting and receiving element and the light emitting and receiving lens are fixed. It becomes possible to produce a charging switch with a uniquely defined detection distance.

Particularly when mass-producing charging switches with the same detection distance, there is no need to adjust the relative positions of the light emitting/receiving elements and the light emitting/receiving lenses one by one, thereby increasing production efficiency.

Furthermore, since the side wall is removed from the light emitting hood and not the light receiving hood, removing the side wall does not affect the characteristics of the photoelectric switch in any way.

This is because it is essential for light-receiving hoods to have an outer peripheral wall to prevent the direct incidence of light from the light-emitting element and the incidence of ambient light, but for light-emitting hoods, there is no outer peripheral wall. However, if no obstacles are placed in the path of the projected light from the light projecting element to the lens attached to the light projecting hood, the amount of projected light will not be obstructed and the objective can be achieved. .

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, 1 is a reflective photoelectric switch according to this invention.

This reflective photoelectric switch 1 includes a case 11 that houses electronic circuits such as a light emitting element, a light receiving element, an amplification circuit, and a switching circuit, and a cover 13 that closes the opening of this case 11.
and a back cover 12 for covering the terminal group provided on the back surface of the case 11.

The case 11 will be explained with reference to FIGS. 2 and 3. The front side of the case 11 has an opening, and the back side of the case 11 has a section 11h with five terminal holders. It is a provision.

This terminal holder has an elongated gap 111 on the right side of the part 11h,
and a number of grooves 11k corresponding to the terminals 14, respectively.

The elongated gap 11i is for inserting and holding a rear end 19a of a printed circuit board 19, which will be described later, and the groove 11k is a groove into which a tongue piece of the terminal 14 is inserted.

To explain the structure of this case 11 in more detail, first, a screw hole 11l is provided at the upper center of the back of the case.

This screw hole 11l is for screwing the back cover 12.

There is a hole 11e on the side of the case for fixing a hexagonal bolt.
, and a through hole 11 f for the bolt.

This allows the case 11 to be attached using this hole 11f when the case 11 is attached.

Further, grooves 11g are provided at the lower left and right sides of the case 11, and the retaining pieces 1 of the back cover 12 are provided in the grooves 11g.
2b can be engaged.

Therefore, when covering the case 11 with the back cover 12, first insert the engaging piece 12b of the back cover 12 into the groove 1 of the case 11.
1 g ← and by rotating around this engaging part with this back force <-12, the back cover 12 and the back surface of →- can be brought into contact with each other.
By inserting a screw through a hole (not shown) provided on the top surface of the case 11 and tightening and fixing the screw into a screw hole 111 provided on the back surface of the case, the back surface of the case 11 is closed by the back cover 12.

Note that a predetermined number of holes 11 are provided at predetermined locations on the back of the case 11.
m is provided.

Further, the inner surface of the case 11 is provided with a groove 11j.

This groove 11j is for inserting the side edge of a printed circuit board 19, which will be described later.

Now, as shown in FIG. 3, there is a terminal 14 in the groove 11k.
By inserting the tongue piece 14a, the terminal 14 is inserted into the groove 1.
1k, and the terminal piece 14b projects downward from a notch provided on the lower side of the groove 11k.

This terminal piece 14b is electrically connected to a copper foil provided on the edge of a printed circuit board 19, which will be described later, by soldering or the like.

Note that the connection part of the terminal 14 with the external lead wire is the tongue piece 14.
It is configured to have an inclination of about 45° with respect to a.

In addition, the upper surface of the case 11 is provided with a square hole 11b and a round hole 11a, as shown in FIGS.
A round hole 11d is also provided in the C section.

The round hole 11a is provided to check the display light emitting diode, which will be described later, from above the case, and the square hole 11a
1b is a hole provided for pouring resin into this portion to secure the cover after inserting the cover 13 into the case opening, or for inserting an ultrasonic welder for ultrasonic welding.

The round hole 11d is a hole provided so that a knob of a sensitivity adjustment volume (not shown) of an electronic circuit housed in the case can be operated from the outside.

The wide groove 11C is a groove for pasting a label on which five product names, company names, trademarks, etc. are printed.

Further, this embodiment will be explained with reference to FIGS. 4, 5, and 6. In FIG. 4, 15 is an electronic circuit section of a reflective optical switch, and 16 is a light projecting hood. ,
This is an element holder in which light-receiving hoods are arranged in parallel and integrally molded with resin.

This element holder 16 is placed on a printed circuit board 19, and its collar is in contact with the front edge of the printed circuit board 16.

17 is an oscillation circuit 61° amplifier circuit 62 as shown in FIG.
, a detection circuit 63, a switching circuit 64, and other electronic circuits, such as IC circuits, transistors, capacitors, and resistors.

Further, 18 is a light emitting diode for displaying operation.

As shown in FIG.
6 g is formed by resin molding.

A hole is provided at the rear end base of the light receiving hood 16a,
A light receiving element 20 such as a photo diode is fixed in this hole.

Since the light-receiving hood 16a is sloped from the rear end base to the opening, the hood 16a has a substantially conical shape.

A hole is also provided at the rear end base of the light projecting hood 16b, and a light projecting element 21 such as a light emitting diode is fixed in this hole.

The external shape of this light projection hood 16b is also such that the opening 1 is closer to the base than the base.
Although the element holder 16 is sloped toward 6e and has a conical shape, the outer side wall is removed to form an opening 16C, so that the overall shape of the element holder 16 is reduced by this amount.

The opening 16C may be formed by molding the element holder, or may be formed by cutting the hood after molding it so that it has a side wall.

Note that the element holder 16 has a light emitting element 21. A printed circuit board 1 on which an optical axis of a light receiving element 20 and electronic components 17 such as an amplifier circuit and a switching circuit are mounted.
9 is placed on the printed circuit board 19 so that they are parallel to each other.

Further, some of the electronic components 17 such as an amplifier circuit and a switching circuit are arranged and attached near the opening 16C of the light projection hood 16b.

Next, an example of the assembly process of the reflective optical switch according to this embodiment will be briefly explained. First, the printed circuit board 19
A predetermined electronic component 17 is mounted on the top, and then a light emitting element 21 is mounted.
．． An element holder 16 to which the light receiving element 20 is fixed is prepared, and the lead wires 21a and 2Qa of the light emitting element and the light receiving element fixed to the element holder are wired to the printed circuit board 19, and the element holder 16 is connected to the printed circuit board 19. The element holder 16 is placed on the board, and the collar 16g of the element holder 16 is brought into contact with the front edge of the printed circuit board 16.

At this time, the display light emitting diode 18 is inserted into the groove 16f provided at a predetermined location in the collar portion 16g of the element holder (the fourth
(see figure).

Next, cover 1 provided with lenses 13a and 13b
3 is engaged with the element holder 16.

At this time, the grooves 13e provided on both sides of the cover 13 are engaged with the projections 16d provided on the element holder, and the top of the display light emitting diode recess 8 is inserted into the hole 13d provided on the back surface of the upper end 13C of the cover. Insert it.

After this, while being careful not to remove the cover 13 from the printed circuit board 19, insert the printed circuit board 19 into the case while aligning the side edge of the printed circuit board 19 with the groove 11j provided in the case.
The rear end portion 19a of the printed circuit board is inserted into the wide groove 11j provided at the rear end of the case.

By doing so, the rear end 19a of the printed circuit board protrudes somewhat from the back of the case, and the groove 19b provided in the rear end 19a engages with the terminal piece 14b of the terminal 14.

Electrical connection is made by connecting this terminal piece 14b to a copper foil provided around the groove 19b by soldering or the like.

On the other hand, the cover 13 and the opening of the case 11 can be sealed by ultrasonic welding or the like as described above.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the external shape of a reflective charging switch according to an embodiment of the invention, FIG. 2 a is a rear view of the case 11 shown in FIG. 1, b is a side view of the case, and C is a front view of the case. FIG. 3 is a partially cutaway perspective view showing the top and back surfaces of the first illustrated case 11, FIG. 4 is a side view of printed circuit boards etc. stored in the first illustrated case, and FIG. 5 is based on this invention. FIG. 6 is a perspective view showing an embodiment of a light emitting hood and a light receiving hood integrally molded, and FIG. 6 is a block diagram of a reflective photoelectric switch. 11; case, 13; cover, 13a; light receiving lens,
13b; Light projecting lens, 20; Light receiving element, 21; Light projecting element, 16a; Light receiving hood, 16b; Light projecting hood, 1
6C; Opening formed by removing the side wall of the floodlight hood.

Claims (1)

[Scope of utility model registration request] A light emitting element and a light receiving element are housed in a single case, the projected light from the light emitting element is reflected by a reflector, the reflected light is received and detected by the light receiving element, and the light received by the light receiving element is detected. The output is amplified by an amplifier circuit to drive a switching circuit, and a conical projection hood is provided for guiding the projected light from the light projecting element to the outside, and a conical projection hood for guiding the projected light from the light projecting element to the outside, and a conical projection hood for guiding the projected light from the light projecting element to the outside. In a reflective optical switch in which a conical light-receiving hood for guiding the light to the light-receiving element is provided for the light-emitting element and the light-receiving element, a side wall of the light-emitting hood is removed to form an opening; The light emitting hood with side walls removed and the light receiving hood are arranged in parallel and integrally formed to form an element holder, and the light emitting hood and the light receiving hood are fixed to the rear ends of the light emitting hood and the light receiving hood, respectively. The element holder is placed on the printed circuit board so that the optical axis of the optical element and the light receiving element is parallel to the printed circuit board on which a plurality of electronic components such as the amplifier circuit and the switching circuit are mounted, and A cover provided with a light emitting lens and a light receiving lens is engaged with the holder, and some of the plurality of electronic components are placed near the opening formed by removing the side wall of the light emitting hood. Features a reflective optical switch.