CN2446517Y

CN2446517Y - Miniature pyroelectric infrared sensor

Info

Publication number: CN2446517Y
Application number: CN 00249227
Authority: CN
Inventors: 栾长文; 王云生; 庞晓薇
Original assignee: SHANGHAI NICERA SENSOR CO Ltd
Current assignee: SHANGHAI NICERA SENSOR CO Ltd
Priority date: 2000-09-14
Filing date: 2000-09-14
Publication date: 2001-09-05
Anticipated expiration: 2010-09-14

Abstract

The utility model relates to a miniature pyroelectric infrared sensor especially suitable for detecting on concealed occasions, which comprises a pipe base, wherein, a three-layer basal plate distributed with a printed circuit is arranged on three pipe pins of the pipe base, a sensing element is arranged on the basal plate, a special integrated-circuit chip is arranged below the basal plate, a pipe cap with an infrared light-filtering window is covered on the pipe base, and an ultramicro lens is arranged outside the pipe cap. The volume of the integral miniature pyroelectric infrared sensor only is 1/8-1/10 of the volume of the existing sensor having the same function as that of the utility model. The utility model has the advantage of good interference immunity, enlarges the range of use of the original sensor and is simpler for peripheral circuits required by users.

Description

Pyroelectric IR Microsensor

The utility model relates to a kind of infrared sensor, particularly is used for human body and moves the pyroelectric infrared sensor that induction is surveyed.

The human body of mass selling moves the induction passive infrared sensor in the market, generally is made up of Fresnel Lenses, the responsive unit of pyroelectric ceramics, junction field effect transistor etc.When the place ahead of infrared sensor has human body to move, the infrared ray that human body radiation goes out focuses in the responsive unit through Fresnel Lenses, convert infrared signal to electric signal by responsive unit, since this electric signal a little less than, need external amplifier, threshold ratio circuit such as, could control such as light switch, household electrical appliance, alarm.The general volume of the sensor of this structure is bigger, its main cause is that amplifier, Fresnel Lenses occupy bigger volume, this has just limited its usable range, if be used for the automatic control of household electrical appliances, just might destroy the integral layout of household electrical appliances and aesthetic in appearance, relate to the hidden detection occasion of some needs for another example, this structure is just more improper.

The purpose of this utility model provides a kind of Pyroelectric IR Microsensor, and its volume is dwindled greatly, only is the 1/8-1/10 of the sensor sold in the market, needing to be particularly suitable for hidden detection occasion.

In order to realize above-mentioned purpose of the present utility model, be equipped with one or three layers of substrate that is furnished with printed wire on three pins of this sensor by a base, base, be equipped with responsive unit above the substrate, be equipped with a slice integrated circuit (IC) chip below, responsive unit realizes that by the printed wire on the substrate electricity is connected with integrated circuit (IC) chip, be covered with a pipe cap that has an infrared fileter window on the base, be used for the unwanted parasitic light of elimination, pipe cap is equipped with ultra micro lens outward, with the human body radiation signal focus in responsive unit.

Said integrated circuit (IC) chip is made up of impedance inverter circuit, signal amplification circuit, signal comparator circuit.

Said ultra micro lens are to be combined by N single-element lens, when the human body radiation signal, the human body radiation signal are carried out spatial modulation, and focus in the responsive unit.

The design philosophy of ultra micro lens is: single-element lens L ₁, L ₂, work as f ₂=f ₁/ 2, A then ₂=A ₁/ 4, L ₁, L ₂Be single-element lens, f ₁, f ₂Be focal length, equal radius-of-curvature, A ₁, A ₂Be the single-element lens area.The energy that they receive is identical, and detection range is the same, and the area of single-element lens dwindles, and then whole lens dwindle greatly, and form ultra micro lens.

Because it is in the base of 10mm that the volume of the electricity of sensor part and Fresnel Lenses dwindles, makes responsive unit and integrated circuit (IC) chip can be assembled in a diameter easily greatly, the volume that makes whole sensor is for realizing the 1/8-1/10 of the sensor bulk of identical function at present.

Description of drawings of the present utility model is as follows:

The structural representation of Fig. 1, pyroelectric infrared sensor;

Fig. 2, ultra micro lens arrangement synoptic diagram;

Fig. 3, pyroelectric infrared sensor integrated circuit diagram.

The utility model is described in further detail below in conjunction with accompanying drawing:

Pyroelectric infrared sensor as shown in Figure 1, comprise base 1, be equipped with one or three layers of substrate 3 that is furnished with printed wiring on three pin twos of base, be equipped with responsive unit 4 above the substrate, be equipped with integrated circuit (IC) chip 5 below, responsive unit realizes that by the printed wire on the substrate electricity is connected with integrated circuit (IC) chip, be covered with a pipe cap 7 that has an infrared window 6 on the base, infrared window 6 and pipe cap are by black gluing connecing, infrared window 6 is made up of the silicon base optical filter of saturating 7-14 micron, and pipe cap is equipped with ultra micro lens 8 outward.

Said ultra micro lens are to be combined by 16 single-element lenss, and the single-element lens locus is arranged and seen Fig. 2, and single-element lens center of maximum angle is 90 °, adjacent cells lens α ∝ sin ^-10.15, can guarantee that then investigative range is 90 °, in the detection range scope of 2m, detection sensitivity reaches 30cm, and the ultra micro lens are made by the polythene material of saturating infrared radiation.

Said integrated circuit (IC) chip 5 is a slice dedicated IC chip, and its schematic diagram is seen Fig. 3, wherein, and by A ₂, A ₅, A ₁₀Provide reference voltage V to internal circuit _Ref, A ₁For the high impedance input amplifier of the first order, form impedance inverter circuit; By A ₃, A ₇Carry out 5000 times amplification, form signal amplification circuit, A ₄Form low-pass filter, A ₈, A ₉Form Hi-pass filter, A ₁₁The Schmidt that the signal that has been exaggerated is carried out high and low current potential relatively forms signal comparator circuit.Signal relatively is through A ₁₂, A ₁₃Output.

Said responsive unit 4 is made by pyroelectric ceramic material Zirconium lead titanates.

The beneficial effects of the utility model:

1. the utility model integrates impedance transformation, signal amplification, signal comparison circuit to consist of one The IC chip of sheet special use becomes the ultra micro lens with Lens Design, makes the volume of whole sensor greatly Dwindle, make it be particularly suitable for hidden occasion and survey.

2. integrated circuit of the present utility model has adopted preferably bandpass filter and two Schmidt's comparison circuit Deng, make device have preferably anti-interference, can effectively reduce the intrusion of spurious signal etc.

3. the utility model sensor has enlarged the scope of application of original sensor, to the desired periphery of user Circuit is simpler, and economic effect is good.

Claims

1. Pyroelectric IR Microsensor, comprise on three pins (2) of base (1), base and be equipped with one or three layers of substrate (3) that is furnished with printed wire, be equipped with responsive unit (4) above the substrate, be covered with a pipe cap (7) that has infrared fileter window (6) on the base, it is characterized in that:

Be equipped with a slice integrated circuit (IC) chip (5) below the substrate, responsive unit (4) realizes that by the printed wire on the substrate electricity is connected with integrated circuit (IC) chip (5), the outer ultra micro lens (8) that are equipped with of pipe cap (7),

Said integrated circuit (IC) chip is by A ₂, A ₅, A ₁₀Provide reference voltage V to internal circuit _Ref, by A ₁For first order high impedance input amplifier, form impedance inverter circuit; By A ₃, A ₇Carry out 5000 times amplification, form signal amplification circuit; A ₄Form low-pass filter, A ₈, A ₉Form Hi-pass filter, A ₁₁The Schmidt that the signal that has been exaggerated is carried out high and low current potential relatively forms signal comparator circuit, and relatively the signal after is through A ₁₂, A ₁₃Output.

2. according to claim 1 Pyroelectric IR Microsensor, it is characterized in that: said ultra micro lens are to be combined by 16 single-element lenss, and single-element lens center of maximum angle is 90 °, adjacent cells lens α ∝ sin ^-10.15.

3. according to claim 1 Pyroelectric IR Microsensor, it is characterized in that: said responsive unit (4) is made by the pyroelectric ceramic material lead zirconate titanate.

4. according to claim 1 Pyroelectric IR Microsensor, it is characterized in that: said ultra micro lens are to be made by polythene material.