JPS59218924A - Pyroelectric infrared-ray sensor - Google Patents

Abstract

PURPOSE:To reduce the number of component parts and to make wiring easy by incorporating a pyroelectric film and a printed board into an outer case and holding and fixing the peripheral part of the pyroelectric film by the upper parts of conductive upper and lower holders. CONSTITUTION:A circuit element 20 is incorporated into a printed plate 16 and the lower end surfaces of a cylindrical conductive upper holder 22 and a cylindrical conductive lower holder 23 which are stacked through a receiving board 21 consisting of an insulating substance are electrically connected. The peripheral part of the pyroelectric film 25 is held between the ceiling surfaces of the conductive upper and lower holders 22, 23 which have openings at their upper centers. A window member 27 is arranged on the upper surface of the conductive upper holder 22, an outer case 29 is covered to the surface of the window member 27 and the lower end parts of the conductive holders are engaged and coupled with a bottom plate 15. Said constitution makes it possible to reduce the number of component parts and make the wiring easy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pyroelectric infrared sensor using a pyroelectric film, and an object of the present invention is to provide a pyroelectric infrared sensor that is easy to assemble and is inexpensive by improving its structure.

As shown in FIG. 1, a conventional pyroelectric infrared sensor has a lead wire 2 drawn out from a circuit case 1 housing a circuit element, a field effect transistor 3 for impedance matching mounted on the circuit case 1, and a field effect transistor 3 for impedance matching mounted on the circuit case 1. A support base 4 made of an insulating material, an insulating inner case 6 arranged around the outer periphery of the support base 4, a reflective plate 6 disposed on the support base 4, and a ring-shaped wavy shape formed on the reflective plate 6. Nine conductive springs 7 are arranged, and a pyroelectric film 10 whose peripheral edge is held by conductive rings 8 and 9 is further arranged, and is held on the conductive rings 9 and on the insulating inner case 6. A large-diameter conductive ring 11 is provided, a windshield 12 made of silicon or the like that allows infrared rays to pass through is placed on the conductive ring 11, and a metal case 14 having a window hole 13 on the upper surface is placed over the whole. '' With this configuration, an electric signal passes through the conductive ring 8, the conductive spring 71, and the reflection plate 6 to enter the gate of the field effect transistor 3, and the ground circuit passes through the conductive ring 9 and conductive ring 11 to the metal case. The case is grounded at 14. In this way, conventional pyroelectric infrared sensor uses a large number of conductive rings 8, 9, 11, conductive springs, etc., and each component is stacked and finally the metal Since the case 14 and the circuit case 1 are assembled by firmly fixing them, there are drawbacks such as poor conduction sometimes occurring due to misalignment of component parts, etc., and time and effort required for assembly, which is significantly disadvantageous in terms of cost. Ta.

Reference numeral 16 denotes a bottom plate formed of an insulating material such as synthetic resin, and a printed circuit board 16 is mounted on the top surface of the bottom plate 16 in the center.
A protrusion 17 supporting the printed circuit board 16 and a peripheral wall 18 into which the outer periphery of the printed circuit board 16 is fitted are provided. A terminal pin 19 that penetrates the bottom plate 16 and is drawn out downward is fixed to the printed circuit board 16, and a circuit element 2o such as a field effect transistor or an output resistor is incorporated therein. The lower end surfaces of the stacked cylindrical conductive upper holder 22 and conductive lower holder 23 are electrically connected via the pedestal 21. A peripheral portion of a flammable film 26 whose peripheral portion is connected to a conductive ring 24 is held between the ceiling surfaces having an opening at the center of the upper portions of the upper conductive holder 22 and the lower conductive holder 23.

There are still spacers 2 on the two sides of the conductive lower holder 22.
6, a window member 27 made of a sheet metal or the like is disposed, and the outer case 729 has a window hole 28 on the upper surface. It is connected by fitting into the outside of the .

The conductive upper holder 22 and the conductive lower holder 23 may be made of metal or conductive resin,
Furthermore, it may be constructed of a synthetic resin whose surface is plated with metal.

As described above, the pyroelectric infrared sensor of the present invention has a simple structure, so there are few components, and the electrical continuity of the pyroelectric film is connected to the printed circuit board only by the conductive upper and lower holders, making wiring easy. It is reliable and reliable, and it is easy to assemble and has excellent productivity.
It has advantages such as being significantly advantageous in terms of cost, and is of great practical value.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional pyroelectric infrared sensor;
The figure is a sectional view showing an embodiment of the pyroelectric infrared sensor of the present invention. 15...Bottom plate, 16...Printed circuit board, 17...Protrusion, 18...Peripheral wall, 1
9...Terminal bin, 20...Circuit element,
21... Rest, 22... Conductive upper holder, 23... Conductive lower holder, 24...
・Conductive ring, 26...Pyroelectric film, 2
6...Spacer, 2...Window member, 28...Window hole, 29...Outer case. Name of agent: Patent attorney Toshio Nakao and 1 other person-1
:

Claims (1)

[Claims] A printed circuit board equipped with a pyroelectric film and circuit elements is installed inside an outer case in which a window member made of infrared transparent and highly airtight silicone is attached to a window hole in the ceiling surface, and the peripheral edge of the pyroelectric film is is clamped and fixed at the top of a conductive upper holder and a conductive lower holder stacked together via an insulating pedestal, and the lower ends of the conductive upper holder and conductive lower holder are connected to a printed circuit board to generate a pyroelectric infrared ray. sensor.