JPH0416927Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention places a projector and a receiver at intervals of several meters to several tens of meters, and detects dimming due to smoke that has entered between them. The present invention relates to a photoelectric separation type sensor for detecting fire, and in particular to an optical axis alignment device for an emitter and a receiver.

[Conventional technology]

Regarding the alignment of the optical axis of a photoelectric separated type sensor, in addition to providing small transparent windows in the condensing lenses of the emitter and receiver, it is also necessary to connect the emitter and receiver from one emitter and receiver to the other. For example, there is a device that aligns the optical axis by illuminating it with an electric light or the like and looking through this small window at the illumination state of the flashlight.
It is known as Publication No. 58-24889.

[Problem that the invention attempts to solve]

In conventional optical axis alignment, a flashlight or the like is separately prepared as a test projector, and during optical axis alignment work, the flashlight is placed in front of the projector/receiver installed in a high place such as the ceiling. There were also problems such as the need to hold the light for a predetermined period of time and the need for processing to provide a small window in the condensing lens.

[Means for solving problems]

This idea involves installing a new visible light emitting element in the same location as or near the signal emitting/receiving element installed in the focusing lens and focal point of the emitter/receiver. The device is designed to light up the element.

Note that the power source for lighting the visible light emitting element may be used in common as the power source for the emitter and light receiver, but it may also be configured to be newly supplied from the outside when aligning the optical axis.

[Effect]

With the above configuration, the work that conventionally required multiple people to adjust the optical axis of the emitter and receiver, which are generally installed several meters to 100 meters apart, can now be done only on the visible light receiving side. It can be adjusted and
By providing a visible light emitting element near the light emitting and receiving elements, the optical axis can be aligned accurately.

〔Example〕

Next, embodiments of this invention will be described in detail with reference to drawings.

Figure 1 is a diagram showing an embodiment of this invention;
The figure shows the state of use, Figure 3 A, B, and C are side views of main parts showing other embodiments, and Figure 4 shows an example of a circuit for lighting a visible light emitting element. Identical parts have the same symbols. It is shown using

In Fig. 1, 1 is the transmitter/receiver body, 2 is a spherical shaft for adjusting the optical axis, 3 is a mounting member such as a ceiling, 4 is a condenser lens, 5 is a signal emitting/light receiving element, and 6 is a visible light emitting element. , 7 is a roughly L-shaped spring that can be rotated at the fulcrum A.
Light-receiving element holding plates 8 and 9 indicate collimation holes, respectively. In the case of a normal projector, near-infrared light (approximately 9000 Å) modulated with a predetermined pulse is emitted from the signal light-emitting element 5 to prevent noise. The light is emitted and the condensing lens 4
The light is converted into parallel light beams and projected onto a light receiver. In the light receiver, the parallel light beam from the light projector is focused by a condenser lens 4, and is received by a light receiving element 5 provided at its focal point.

To align the optical axes when installing such an emitter/receiver 1, first visually measure the emitter/receiver in a predetermined position and temporarily fix the emitter/receiver facing each other, then use the holding plate 7 of one emitter/receiver as a fulcrum. It is rotated 90 degrees around A and set at the position shown by the dotted line, and the visible light emitting element 6 provided on the holding plate 7 is moved to the location of the signal emitting/light receiving element 5 and turned on. Then, as shown in Fig. 2, look into the visible light emitted from the collimating holes 8 and 9 of the other emitter/receiver 1, align the optical axis accurately with the spherical shaft 2 for optical axis adjustment, and fix it. be done. These operations are performed in the same way on both the emitter and receiver sides.

Note that a lever (not shown) or the like is provided so that the holding plate 7 can be rotated from the outside of the main body 1.

FIG. 3 shows another example of how the visible light emitting element 6 shown in FIG. 1 is attached. In FIG. 3(a), a visible light emitting element 6 made of a doughnut-shaped surface light emitter is provided around the signal emitting/light receiving element 5, and in FIG. 3(b), a fulcrum B is shown. It is equipped with an L-shaped plate 71 in the center as shown by the dotted line, and a visible light-emitting element 6 is provided so that it is located in front of the signal emitting/light-receiving element 5 when pushed down as shown by the arrow. show. FIG. 3C shows a structure in which an infrared emitting/receiving element 5 and a visible light emitting element 6 are installed together in one resin mold. In this case, the signal emitting/receiving element 5 and the visible light emitting element 6 Use one with terminals pulled out so that both can be turned on individually.

FIG. 4 shows an example of a lighting circuit for the visible light emitting element 6. In this figure, the power supply 12 is used as both a signal power supply and a visible light emission power supply. 10 is a polarity switching circuit, 11 is a signal processing circuit, 5 is a light emitting/receiving element, 6 is a visible light emitting element, and D ₁ and D ₂ are backflow prevention diodes, respectively.

In the figure, normally the diode _D1 side is set to a positive voltage, and the signal processing circuit 11 is activated. When aligning the optical axis, diode D ₂
The visible light emitting element 6 is turned on by reversing the polarity so that the voltage on the side becomes positive. These changes can be made by providing a changeover switch (not shown) or the like outside the emitter/receiver 1.

If the visible light emitting element 6 is to be lit by a separate power source, it is sufficient to provide a plug etc. drawn out with a lead wire in advance to the main body 1, and when aligning the optical axis, insert this plug into the power outlet. A visible light element can be turned on, and a battery can also be used as a power source.

〔effect〕

As described above, the photoelectric separation type sensor of this invention has the characteristics that the optical axis adjustment work can be easily performed by one person and can be performed more accurately.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing one embodiment of the photoelectric separation type sensor of this invention, Fig. 2 is a diagram showing its usage state, and Fig. 3 A, B, and C are side views of main parts of another embodiment. 4 each show a lighting circuit diagram of a visible light emitting element. 1...Emitter/receiver body, 4...Condensing lens, 5
... Signal emitting/light receiving element, 6... Visible light emitting element,
7... Holding plate, 8, 9... Sighting hole.

Claims (1)

[Scope of utility model registration request] An emitter and a receiver, each having a sighting hole for aligning the optical axis, are placed apart from each other at a predetermined monitoring distance, and light reduction caused by smoke entering between the emitter and receiver is detected and a fire is detected. In the photoelectric separation type sensor that detects the above, a visible light-emitting element is provided at the same location as the emitter/light-receiving element at the focal point of the condensing lens of each of the emitters/receivers, or in the vicinity thereof, and when aligning the optical axis,
A circuit is provided to light up the visible light emitting element, and the other
A photoelectric separation type sensor characterized in that the optical axis is aligned by visually observing the visible light emitted from the visible light emitting element through a collimation hole of a light receiver.