JPH0549169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical wireless receiver.

[Prior Art] Conventionally, this type of optical wireless receiver
Attachment holes 8 drilled in the ceiling 8 as shown in the figure
It is designed to be embedded in a. By the way, as shown in FIG. 7, in the optical wireless receiver ), and is disposed so that the counterbore 3c faces the opening 2, and the light receiving element 4 disposed inside the housing 1 is disposed at the condensing point of the condensing lens 3. ing. Further, within the housing 1, a signal processing channel section 5 is provided which includes an amplifier and the like for amplifying the light reception signal output from the light receiving element 4. In addition,
FIG. 8 shows the outer surface 3a and inner surface 3 of the condensing lens 3.
It is a light condensing characteristic diagram when the curved surface of the counterbore part 3c of b is designed with an appropriate exponential function to obtain the desired light condensing characteristic. Furthermore, it goes without saying that the optical wireless receiver X may be attached to a wall. Furthermore, a visible light cut filter 6 is disposed between the condenser lens 3 and the opening 2 of the housing 1. An annular recess 7 is provided on the inner surface 3b of the condenser lens 3 to prevent color unevenness from occurring due to irregular contact with the condensing lens 3.

[Problem to be solved by the invention] However, in the above-mentioned conventional example, a large temperature difference occurred between the temperature in the ceiling (or behind the wall), that is, the temperature inside the optical wireless receiver X, and the temperature inside the room. In this case, there was a problem in that the temperature difference between the outer surface 3a and the inner surface 3b of the condenser lens 3 became large, causing dew condensation on the inner surface 3b of the condenser lens 3, and the light condensing performance was significantly reduced. In addition, since the air remaining in the annular recess 7 and the counterbore 3c has the same temperature and humidity as the air in the attic, condensation is likely to occur, and once condensation occurs, water droplets form in the counterbore 3c. However, there was a problem in that the light did not disappear easily, and the light-collecting characteristics were impaired, making it impossible to obtain the original receiving performance (reaching distance, light-receiving angle, etc.).

The present invention has been made in view of the above points, and its purpose is to provide an optical wireless receiver that is less likely to suffer deterioration in light collection characteristics due to dew condensation and that does not impair its appearance. be.

[Means for Solving the Problems] The optical wireless receiver of the present invention includes a condensing lens having a counterbore in the center of the inner surface, covered with the condenser lens such that the counterbore faces the opening of the housing, and provided in the housing. In this optical wireless receiver, a light-receiving element is arranged at the focal point of a condensing lens, and an opening groove for ventilation is provided on the surface facing the housing of the condensing lens to allow air in the counterbore and outside air to circulate. .

[Function] The present invention is configured as described above, and the housing-facing surface of the condensing lens having the counterbore covered with the opening of the housing is provided with a ventilation opening groove that allows air in the counterbore and outside air to circulate. The convection between the air inside the counterbore and the outside air is achieved through this ventilation opening, which reduces the temperature difference between the outer surface of the condensing lens and the counterbore, reducing the condensing properties caused by condensation. It has become difficult for this to occur.
Further, since the ventilation opening groove opens laterally on the housing side of the condenser lens, the ventilation opening does not stand out and the appearance is not impaired.

[Embodiment] Figures 1 and 2 show a schematic configuration of the main parts of an embodiment of the present invention, in which a counterbore 3c is provided at the center of the inner surface.
It is formed by covering a condensing lens 3 having the above-mentioned counterbore portion 3c facing the opening 2 of the housing 1, and arranging the light receiving element 4 provided in the housing 1 at the condensing point of the condensing lens 3. , in an optical wireless receiver X similar to the conventional example arranged on a ceiling 8 or a wall surface, the ventilation opening grooves 10a and 10b for circulating the air in the counterbore 3c and the outside air are connected to the surface facing the housing of the condenser lens 3. It was established in A projecting wall 3d for welding is provided on the circumference of the condenser lens 3, and is attached to the housing 1 by ultrasonic welding. Alternatively, the condenser lens 3 may be attached to the housing 1 using an adhesive.

FIG. 3 shows a circuit example of the signal processing circuit section 5, which includes a light receiving module 20 and a signal processing route 21.
, a signal output circuit 22 , and a power supply circuit 23 .

FIG. 4 shows a schematic configuration of a remote monitoring and control system using the optical wireless receiver Terminal 3
3. A wireless relay terminal 37, an external interface terminal 38, and a pattern setting terminal 39 are connected by a pair of traffic lights 34,
As shown in FIG. 5a, the transmission signal Vs sent from the central control device 31 to the signal line 34 includes a start pulse signal ST indicating the start of signal transmission, a mode data signal MD indicating the signal mode, and the terminal devices 32 and 3.
Address data signal AD that transmits 8-bit address data calling 3, 37 to 39, load L ₁
A bipolar (±24V) consisting of a control data signal CD that transmits control data that controls ~ _L4 , a checksum data signal CS, and a return standby signal WT that sets the return period from the terminals 32, 33, 37 to 39.
It is a time division multiplexed signal, and data is transmitted by pulse width modulation. When the address data of the transmission signal Vs received via the signal line 34 and its own unique address data match, each terminal device 32, 33, 37 to 39 takes in the control data of the transmission signal Vs and transmits the signal. The monitoring data signal is returned as a current mode signal (a signal sent by short-circuiting the signal lines 34 via an appropriate low impedance) in synchronization with the return standby signal WT of the signal Vs. Also,
The central control device 31 includes a dummy signal transmitting means that always sends out a dummy transmission signal with the mode data signal MD in a dummy mode, and one of the monitoring terminals 32, wireless relay terminals 37, and external interface terminals 38. , when an interrupt signal Vi as shown in FIG.
2, 37 to 39 and an interrupt processing means for returning monitoring data. In addition, the central control device 31 also operates the monitoring terminal 32 or the wireless relay terminal 3 as described above.
7. Corresponding loads L ₁ to _{L 4} based on the monitoring data sent back to the central control device 31 from the external interface terminal 38 and the pattern setting terminal 39
At the same time, the control data is time-division multiplex transmitted to the control terminal 33 via the signal line 34 to control the loads L ₁ to _{L 4} . It's becoming like that.

Here, the wireless relay terminal device 37 is a terminal device that performs data relay of an optical wireless system consisting of an optical wireless transmitter Y, a wireless receiver X according to the present invention, and a wireless signal line 40, and the optical wireless transmitter Y The optical wireless receiver X receives the optical signal transmitted from the optical wireless receiver X, receives the received data via the wireless signal line 40, and transfers this data to the central controller 31. Further, the external interface terminal device 38 is a terminal device that performs data transmission with the external control device 41, and the pattern setting terminal device 39 transfers pattern control data input from the data input section 42 to the central control device 31. It is a terminal device that transfers data to The monitoring terminal device 32 and the control terminal device 33 installed in the distribution board 36 or the relay control panel 36a have the dimensions agreed upon in the distribution board agreement, and their control outputs are used for load control. A remote control relay (a latching relay that can be turned on and off using a hand switch) 35 is controlled.

The dew condensation prevention operation of the optical wireless receiver X according to the present invention will be explained below. Now, a condenser lens 3 is covered with an opening 2 of a housing 1 of an optical wireless receiver X installed on a ceiling 8 or a wall.
Ventilation opening grooves 10a, 10b are formed in the condenser lens 3 so that outside air flows through the ventilation opening grooves 10a, 10b to the counterbore 3c formed on the inner surface 3b of the condenser lens 3. Because I'm getting used to it,
The temperature difference between the outer surface 3a and the counterbore 3c of the condenser lens 3 is almost eliminated, and the counterbore 3c of the condenser lens 3 is reduced.
It is designed so that dew condensation is unlikely to occur, so that the light collecting characteristics are not impaired and the receiving performance is not deteriorated.

[Effects of the Invention] The present invention is configured as described above, and has a counterbore that is covered with the opening of the housing.The housing-facing surface of the condensing lens has a counterbore that is covered with the opening of the housing. It has an opening groove, and convection between the air inside the counterbore and the outside air is achieved through the ventilation opening, which reduces the temperature difference between the outer surface of the condensing lens and the counterbore, reducing the risk of condensation. This has the effect that deterioration in light-condensing characteristics is less likely to occur. Also, since the ventilation opening groove opens laterally on the housing side of the condenser lens,
The effect is that the ventilation openings are not conspicuous and the appearance is not impaired.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main parts of an embodiment of the present invention, Fig. 2 is a top view of the main parts of the improvement, Fig. 3 is a circuit diagram of the main parts of the same, and Fig. 4 shows an optical wireless receiver according to the present invention. Schematic configuration diagram of the remote monitoring and control system used, Part 5
6 is a cross-sectional view showing an example of the arrangement of the optical wireless receiver according to the present invention; FIG. 7 is a cross-sectional view showing a schematic configuration of the main parts of the conventional example; and FIG. It is an operation explanatory diagram. 1 is a housing, 2 is an aperture, 3 is a condenser lens,
3a is an outer surface, 3b is an inner surface, 3c is a counterbore, 4 is a light receiving element, 5 is a signal processing circuit section, 10a, 10b
is an opening groove for ventilation, and X is an optical wireless receiver.

Claims (1)

[Claims] 1. A light beam formed by covering a condensing lens having a counterbore in the center of its inner surface so that the counterbore faces the opening of the housing, and arranging a light-receiving element provided inside the housing at the condensing point of the condenser lens. What is claimed is: 1. An optical wireless receiver characterized in that a ventilation opening groove is provided on a surface facing a housing of a condensing lens to allow air in the counterbore and outside air to circulate.