JPH04248422A - Infrared detector - Google Patents

Abstract

PURPOSE:To accurately detect a human body even in a low temp. zone by providing a heater heating a case main body to the box body receiving the case main body in such a state that a light incident window is opposed to an opening part. CONSTITUTION:An infrared ray detection apparatus 1 is constituted of a resin case main body 3 having a light incident window 2 formed to the lower part thereof, the infrared detection element 4 provided in the case main body 3, the receiving box body 5 receiving the case main body 3 and the electric heater 6 as the heater heating the case main body 3. Infrared beam incident from an optical system is condensed to the infrared detection element 4 through an infrared transmission filter 10 and an optical filter 8 and the detection element 4 converts the change of the incident infrared beam to an electric signal. Next, the electric signal is amplified and it is judged whether the amplified signal is equal to or more than a detection level and, when said signal is the detection level or more, a human body detection signal is outputted. A human body can be accurately detected even in a low temp. zone and this detection signal is utilized as the control signal of an automatic door.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detection device that can be used in an infrared moving object detection device that detects the presence or absence of a human body in a non-contact manner and controls the opening and closing of automatic doors.

0002

2. Description of the Related Art Conventional infrared detection devices of this type include a case as shown in, for example, Japanese Unexamined Patent Publication No. 2-75917.
An infrared detection element is installed in the body opposite to the light entrance window, and this infrared detection element converts the infrared light flux incident from the light entrance window into an electrical signal corresponding to the amount of variation in the infrared light flux. The infrared detector is equipped with an infrared detector, and a circuit board on which the infrared detector is mounted is enclosed in a shield case having a light incidence part, with the infrared detection element facing the light incidence part. be.

[0003] Such an infrared detection device is used to detect a change in infrared light flux caused by a human body entering a detection area, and output an opening/closing signal for an automatic door.

0004

[Problem to be Solved by the Invention] When such an infrared detection device is used in a low ambient temperature range (approximately -20°C), for example inside a freezer, condensation or freezing of condensed water may occur. However, in particular, if dew or ice forms on the light entrance window or the infrared detection element, there is a problem in that the human body cannot be detected accurately.

SUMMARY OF THE INVENTION An object of the present invention is to provide an infrared detection device that can solve the above problems and accurately detect a human body even in a low temperature range.

[0006]

[Means for Solving the Problems] The present invention includes a case body in which a light entrance window is formed, and a case body that faces the light entrance window.
an infrared detection element that is installed in the main unit and converts the infrared rays incident from the light incidence window into an electrical signal according to the amount of variation in the infrared rays;
It has an opening blocked by an infrared transmission filter,
The infrared detecting device includes a storage box body that houses the case body with the light incidence window facing the opening, and a heating element that heats the case body inside the box body.

[0007]

[Function] According to the present invention, the case body is heated by the action of the electric heater as a heating element, thereby preventing dew condensation or freezing on the light entrance window and the infrared detection element. can.

Furthermore, since the opening of the storage box body is closed by an infrared transmission filter, it is possible to prevent cold air from entering the storage box body, and the case body can be heated efficiently.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical side view of the infrared detection device 1, FIG. 2 is a perspective view of the infrared detection device 1, and FIG. 3 is an exploded perspective view of the infrared detection device 1. A case body 3 made of resin with a window 2 formed therein, an infrared detection element 4 built into the case body 3, a storage box body 5 for storing the case body 3, and a case body 3. It is composed of an electric heater 6 and the like as a heating element.

The infrared detecting element 4 is disposed facing the light entrance window 2, and converts the infrared light flux incident from the light entrance window 2 into an electric signal corresponding to the amount of variation thereof. The light entrance window 2 is an opening 7 formed on the lower surface of the case body 3.
An optical filter 8 is disposed and formed. Further, the storage box body 5 is configured to be divisible into a front lid 5A consisting of upper and lower surfaces and a front surface, and a rear lid 5B consisting of left and right side surfaces and a rear surface. Among these, an opening 9 is formed on the lower surface of the front lid 5A, and an infrared transmission filter 10 for closing the opening 9 is disposed, and the rear surface of the rear lid 5B is provided with the electric heater. Mounting plate 1 with data 6 attached to the back side
1 is fixed.

After the case body 3 is removably fixed to the front surface of the mounting plate 11 with the screws 12,
A storage box body 5 is constructed by combining the front lid 5A and the rear lid 5B. At this time, the case body 3 has its light entrance window 2 connected to the storage box body 5.
It is disposed so as to face the opening 9 of.

In the above configuration, the infrared detection device 1 condenses the infrared light flux incident from the optical system (not shown) onto the infrared detection element 4 via the infrared transmission filter 10 and the optical filter 8. 4 converts the change in the incident infrared light flux into an electrical signal, amplifies this electrical signal, determines whether this amplified signal is above the detection level, and when it is above the detection level, outputs a human body detection signal. Output. This detection signal is then used as a signal to control opening of the automatic door.

By the way, the infrared detection device 1 of the present invention has the following features:
By energizing the electric heater 6, the case body 3 is heated when the ambient temperature is extremely low, for example, when used inside a freezer. It is possible to prevent dew condensation and freezing of condensed water on the window 2 and infrared detection element 4, and also to prevent dew condensation and freezing of condensed water on the storage box body 5 and infrared transmission filter 10, and to improve human body detection operation. can be performed accurately.

Moreover, since the opening 9 of the storage box body 5 is closed by the infrared transmission filter 10, the storage box body 5
Intrusion of cold air into the case body 3 is also prevented, and the case body 3 can be heated efficiently.

[0015]

Effects of the Invention: When the infrared detection device according to the present invention is used in an extremely low ambient temperature range, it can prevent dew condensation and freezing of condensed water on the light entrance window and the infrared detection element, thereby preventing human body damage. The detection operation can be performed accurately.

Moreover, since cold air is prevented from entering the storage box, the case body can be heated efficiently, and a more reliable human body detection operation can be performed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view of an infrared detection device.

FIG. 2 is a perspective view of an infrared detection device.

FIG. 3 is an exploded perspective view of the infrared detection device.

[Explanation of symbols]

1 Infrared detection device 2. Light entrance window 3 Case body 4 Infrared detection element 5 Storage box body 6 Electric heater 9 Opening 10 Infrared transmission filter

Claims (1)

[Claims] 1. A case body in which a light entrance window is formed, and a case body which is installed in the case body facing the light entrance window, and which converts infrared rays incident from the light entrance window into an electrical signal according to the amount of variation thereof. an infrared detecting element that converts the light into an infrared light, a storage box body that has an opening closed by an infrared transmission filter, and houses the case body with the light entrance window facing the opening; An infrared detection device comprising a heating element that heats the case body.