JPH0896263A - Device and method for varying detection area of pyroelectric element sensor - Google Patents

Abstract

PURPOSE: To easily and efficiently change a detection area by a simple mechanism by vertically moving an electric circuit substrate fixing a pyroelectric element to its lower surface in an instrument body so as to increase/decrease a relative distance between the element and a Fresnel lens-like light converging cover fitted to the lower part of the instrument body. CONSTITUTION: The pyroelectric element 3 to be a hot-wire sensor is fixed to the lower surface of the electric circuit substrate 1 and the substrate 1 is fitted to the instrument body 4 so as to be vertically moved to change a distance from a ceiling plate 5 e.g. The Fresnel lens-like light converging cover 2 is fitted to the body 4 so as to cover the substrate 1. When the substrate 1 is vertically moved (an arrow X direction) in the body 4 against the ceiling surface 5, a distance L between the element 3 fixed to the lower surface of the substrate 1 and the cover 2 is changed, so that the focus of a Fresnel lens of the cover 2 is changed and a heat detecting area by the element 3 can be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a pyroelectric element as a heat ray sensor to warn a suspicious person from invading a fire or to notify a visitor. The present invention relates to a detection area changing device for a pyroelectric element sensor and a detection area changing method thereof.

[0002]

2. Description of the Related Art FIG. 5 is a schematic sectional front view showing an example of a conventional detection area varying device for a pyroelectric element sensor. In FIG. 5, a is a pyroelectric element b as a heat ray sensor.
, An optical system including c, a main body of an instrument containing the optical system a, d
Is a Fresnel lens-shaped light collecting cover. The light-collecting cover d is attached to the opening of the instrument body c, and has a dustproof and waterproof function for the optical system a in the instrument body c, and the light-collecting cover d slides to focus with the optical system a. By changing the relative positional relationship with the electric element b,
The detection area of the pyroelectric element b as a heat ray sensor is changed.

FIG. 6 is a schematic front view showing another example of a conventional detection area varying device for a pyroelectric element sensor. The cover of the instrument body e incorporating an optical system including a pyroelectric element as a heat ray sensor. A zoom lens g is provided at the center of f, and the focus position is changed by the vertical movement of the zoom lens g as the cover f moves up and down to change the detection area.

[0004]

In the former case of the above-mentioned conventional example, the Fresnel lens-like portion of the light collecting cover d is narrow and small, and the infrared rays incident on the pyroelectric element b are irradiated. This is not sufficient, and therefore the detection area of the pyroelectric element b is narrowed. In the latter of the conventional examples described above, the focus position is changed by the vertical movement of the zoom lens g associated with the vertical movement of the cover f. However, since the cover f is relatively heavy, the vertical movement operation is troublesome. However, there is a problem in that it is difficult to adjust the focus of the zoom lens g.

In view of the above problems, the present invention provides a pyroelectric element mounted on the lower surface of an electric circuit board by moving the electric circuit board up and down in the main body of the instrument. To increase or decrease the relative distance to the Fresnel lens-shaped light collecting cover attached to the bottom of the instrument body, change the detection area by the pyroelectric element easily and efficiently with a simple mechanism. It is an object.

[0006]

In order to achieve the above object, a detection area varying device for a pyroelectric element sensor according to the present invention is an electric circuit board on which a pyroelectric element as a heat ray sensor is attached on the lower surface. Is mounted so as to be movable up and down in the instrument body, and a Fresnel lens-shaped light-collecting cover is attached to the lower portion of the instrument body so as to cover the electric circuit board and the pyroelectric element. It is a thing.

Further, in the method for changing the detection area of the pyroelectric element sensor according to the present invention, the electric circuit board is moved up and down in the instrument body, and the pyroelectric element mounted on the lower surface of the electric circuit board, It is characterized in that the distance to the Fresnel lens-shaped light collecting cover mounted on the lower part of the instrument body is changed.

[0008]

Next, the function of the present invention will be described. When the electric circuit board is moved up and down with respect to the ceiling surface in the instrument body, the distance between the pyroelectric element and the Fresnel lens-shaped light collecting cover mounted on the lower surface of the electric circuit board changes, The focus is changed to change the heat detection area by the pyroelectric element, and when the distance between the pyroelectric element and the Fresnel lens-shaped light collecting cover is short, the detection area by the pyroelectric element becomes large, Further, when the distance between the pyroelectric element and the Fresnel lens-shaped light collecting cover is long, the detection area by the pyroelectric element becomes small.

[0009]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a first embodiment of a detection area changing device for a pyroelectric element sensor and a detection area changing method according to the present invention.
2 is a schematic cross-sectional front view showing the embodiment of FIG. In this figure, reference numeral 1 denotes an electric circuit board having a pyroelectric element 3 as a heat ray sensor mounted on the lower surface thereof.
Is attached to the instrument body 4, and is vertically movably attached to the instrument body 4 so that the position where the instrument body 4 is attached, for example, the distance to the ceiling plate 5 changes.
2 is an electric circuit board 1 on which a pyroelectric element 3 is mounted on the lower surface
Is a Fresnel lens-shaped light-collecting cover that is attached to the instrument body 4 to cover.

In the detection area changing device and the detection area changing method for the pyroelectric element sensor of the first embodiment shown in FIG. 1, the electric circuit board 1 is moved up and down in the instrument body 4 with respect to the ceiling surface 5 (see FIG. 1 in the direction of the arrow X), the distance L between the pyroelectric element 3 provided on the lower surface of the electric circuit board 1 and the Fresnel lens-shaped light collecting cover 2 changes, and the Fresnel of the light collecting cover 2 changes. The focus of the lens fluctuates and the heat detection area by the pyroelectric element 3 can be changed.

FIG. 2 is an explanatory view of the detection area changing operation by the pyroelectric element 3. In FIG. 2A, the distance L between the pyroelectric element 3 and the Fresnel lens-shaped light collecting cover 2 is short. FIG. 2B is a schematic cross-sectional front view showing the state when the detection area is large, and FIG. 2B shows that the distance L between the pyroelectric element 3 and the Fresnel lens-shaped light collecting cover 2 is long (the detection area is It is a schematic cross-sectional front view showing a state of (small). In addition,
M in the drawing indicates a line of the range of the detection area.

FIG. 3 is a schematic sectional front view showing a second embodiment of the detection area changing apparatus for a pyroelectric element sensor and the detection area changing method according to the present invention. In this figure
The same reference numerals as those in FIG. 1 are attached to the portions corresponding to the respective portions. Reference numeral 6 in the figure denotes a board for fixing the instrument body 4 to the ceiling board 5, and screws 7 are provided on the ceiling board 5 and the board 6.
Is vertically movably passed through to fix the tip of the screw 7 to the electric circuit board 1, and the screw portion of the screw 7 is rotatably screwed to the ceiling plate 5 and / or the board 6. . Reference numeral 8 in the drawing is a screwdriver for operating the screw 7.

The operation of the second embodiment of the detection area changing device of the pyroelectric element sensor and the detection area changing method according to the present invention will be described. When the screwdriver 8 is operated to rotate the screw 7, the electric circuit board 1 moves vertically in the instrument body 4 with respect to the ceiling board 5 and the board 6.
By changing the distance L between the pyroelectric element 3 provided on the lower surface of the electric circuit board 1 and the Fresnel lens-shaped light collecting cover 2, the focus of the Fresnel lens of the light collecting cover 2 is changed. The detection area by the pyroelectric element 3 can be changed.

FIG. 4 is a schematic sectional front view showing a third embodiment of the detection area changing apparatus for a pyroelectric element sensor and the detection area changing method according to the present invention. In this figure
The same reference numerals as those in FIG. 1 are attached to the portions corresponding to the respective portions. Reference numeral 9 in the drawing is a rod, and the base end of the rod 9 is vertically fixed to the upper surface of the electric circuit board 1, and the rod 9 is vertically movably penetrated through the ceiling plate 5. The tip of 9 is connected to one end of a swinging rod 10 which is tiltable about a support rod 11 provided on the upper surface of the ceiling surface 5 as a fulcrum.

The operation of the fourth embodiment of the detection area changing device for the pyroelectric element sensor and the detection area changing method according to the present invention will be described. When the rod 9 is moved up and down and the electric circuit board 1 in the instrument body 4 is moved up and down, the pyroelectric element 3 and the Fresnel lens-shaped light collecting cover 2 attached to the lower surface of the electric circuit board 1 are moved. By changing the distance L between them, the focus of the Fresnel lens of the condenser cover 2 can be changed to change the detection area by the pyroelectric element 3.

That is, when point A is pressed in the direction of arrow x in the state shown in FIG. 4 (A), the lever 9 of the rocking rod 10 causes the rod 9 to be pulled upward, so that the electric circuit board 1 is a tool. 4 (B) by moving upward in the main body 4 and the distance L between the pyroelectric element 3 and the Fresnel lens-shaped light-collecting cover 2 becomes longer, and the detection area by the pyroelectric element 3 becomes larger. Get smaller. On the contrary, Fig. 4
When the point B is pushed in the direction of arrow x in the state shown in (B), the lever 9 of the swing rod 10 pushes the rod body 9 downward, so that the electric circuit board 1 moves downward in the instrument body 4. 4A, the distance L between the pyroelectric element 3 and the Fresnel lens-shaped light collecting cover 2 is shortened, and the detection area by the pyroelectric element 3 is reduced.

[0017]

According to the detection area varying device for a pyroelectric element sensor of the present invention, an electric circuit board having a pyroelectric element as a heat ray sensor mounted on its lower surface can be moved up and down in the instrument body. Mounted on the electric circuit board and the pyroelectric element, the Fresnel lens-shaped condensing cover is mounted on the lower part of the instrument body, so that the Fresnel lens-shaped portion of the condensing cover becomes wide and large. Irradiation of infrared rays entering the pyroelectric element can be fully utilized, and there is an advantage that the detection area by the pyroelectric element can be efficiently changed despite the simple mechanism.

Further, in the method for varying the detection area of the pyroelectric element sensor according to the present invention, the electric circuit board is moved up and down in the main body of the instrument, and the pyroelectric element attached to the lower surface of the electric circuit board and the instrument. Since the distance to the Fresnel lens-shaped light collecting cover attached to the lower part of the main body is changed, there is an advantage that the detection area changing operation by the pyroelectric element can be smoothly performed by a simple operation. is there.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional front view showing a first embodiment of a detection area changing device for a pyroelectric element sensor and a detection area changing method according to the present invention.

FIG. 2 is an explanatory view of a detection area changing operation by the pyroelectric element, and (A) is a schematic cross-sectional front view showing a state when the distance between the pyroelectric element and the Fresnel lens-shaped light collecting cover is short. FIG. 4B is a schematic cross-sectional front view showing a state in which the distance between the pyroelectric element and the Fresnel lens-shaped light collecting cover is long.

FIG. 3 is a schematic cross-sectional front view showing a second embodiment of the detection area changing device of the pyroelectric element sensor and the detection area changing method according to the present invention.

FIG. 4 is a schematic cross-sectional front view showing a third embodiment of a detection area changing device for a pyroelectric element sensor and a detection area changing method according to the present invention, in which (A) is an action of a lever of a rocking rod. The front view which shows the state by which the rod was pushed down by, and (B) is the front view which shows the state in which the rod was pulled up by the action of the lever of the rocking rod.

FIG. 5 is a schematic sectional front view showing an example of a conventional detection area varying device for a pyroelectric element sensor.

FIG. 6 is a schematic front view showing another example of a conventional detection area varying device for a pyroelectric element sensor.

[Explanation of symbols]

 1 Electric Circuit Board 2 Fresnel Lens-Shaped Condensing Cover 3 Pyroelectric Element 4 Instrument Main Body 5 Ceiling Board X Electric Circuit Board Vertical Movement Direction

Claims (4)

[Claims] 1. An electric circuit board having a pyroelectric element as a heat ray sensor mounted on the lower surface thereof is mounted so as to be vertically movable within the instrument body, and the electric circuit board and the pyroelectric element are attached. A device for changing a detection area of a pyroelectric element sensor, characterized in that a Fresnel lens-shaped light collecting cover is attached to a lower portion of the instrument body so as to cover it. 2. An electric circuit board is moved up and down in the main body of the instrument to provide a pyroelectric element mounted on the lower surface of the electric circuit board and a Fresnel-lens-shaped assembly attached to the lower portion of the main body of the instrument. A method for varying the detection area of a pyroelectric element sensor, characterized in that the distance to the optical cover is changed. 3. The method for changing a detection area of a pyroelectric element sensor according to claim 2, wherein the electric circuit board is moved up and down in the instrument body by operating a screw having a lower end fixed to the electric circuit board. 4. A tip end of a rod whose base end is vertically fixed to the upper surface of the electric circuit board and which vertically penetrates the ceiling surface uses a supporting rod provided on the upper surface of the ceiling surface as a fulcrum. 3. The variable detection area of a pyroelectric element sensor according to claim 2, wherein the electric circuit board is connected to one end of a tiltable swinging rod, and the lever action of the swinging rod moves the electric circuit board up and down in the instrument body. Method.