GB2500346A

GB2500346A - Component for optical sensor

Info

Publication number: GB2500346A
Application number: GB1311521.7A
Authority: GB
Inventors: Yasuhiro Tanabe; Koji Hayashi; Fuminori Nakamura
Original assignee: Murata Manufacturing Co Ltd; Nalux Co Ltd
Current assignee: Murata Manufacturing Co Ltd; Nalux Co Ltd
Priority date: 2010-12-15
Filing date: 2011-12-01
Publication date: 2013-09-18
Anticipated expiration: 2031-12-01
Also published as: WO2012081409A1; CN103261856B; CN103261856A; GB2500346B; JPWO2012081409A1; GB201311521D0; JP5499257B2

Abstract

Provided is a component for an optical sensor, such that the component has a simple configuration and can be combined with an optical sensor having a small size. The component for an optical sensor according to the first embodiment of the invention is an integral-molded tubular component used in combination with an optical sensor (201, etc.). One end surface of the tube is combined with the optical sensor and the other end surface (101, etc.) comprises a lens for focusing external light onto the optical sensor. This component for an optical sensor is provided with multiple ribs (103, etc.) inside the tube at at least three circumferential positions of the tube, such that the ribs are contiguous to the lens and the inner surface of the tube.

Description

COMPONENT FOR OPTICAL SENSOR

Field of the invention bow.]

The present invention relates to a component for an optical sensor.

Background Mt

[0002] Infrared sensors for detecting positions and mol ions of cersons are widely used in household iilectriod appliances such as if con thoner 2nd iii. devices for crime prevention. Optcal. set ors including the ahove mentioned infrared sensors are used in concert with components for optical ensors, which are provided with iCUSOS for collecting extraneous lights.

1:000 31 Fig. 14 shows a conventional system in which an optical. sensor 1201 and.

a compOnent 11.01 for the optical sensoi. are combined. The component 1101 for the optical sensor including a lens is formed such that the optical sensor 1201 can be engaged in it. Such an aptcal sensor and a component for the optical sensor are described in Patent Document 1, for example.

10004] Recently optical sensors have been remarkably downsized. On the other hand, a certain size of the lens is required to maintain optical capability of the letis of coil&ting extraneoit lights. ar optical sensOP of a small sze has to be no. .hined with a component for the optical sensor including a [ens of a relatively large size.

[00051 A separate adaptor component can be need for the combination.

However, the use of such an adaptor component increases the numTler of steps of the manufacturing process and manufacturing costs 10006].

Conventionafiy an ntegral:fbrmed component tbr an optieai sensor which can be comlined with an opUS sensor of a small size while. keeping optical capability of the lens has not been developed.

Prior art document

Patent document 1.00071 Patent document I JP04460179A 1.0 $rnninary of tha invention Problea to be solved by the invention [00081 Accordingly; there is a ne-ed for an intgral-fonned component for an opUS sensor which can be combined with an optical sensor of a small size while keerilngoptithl capability of the lens.

Means for solving, the problem [000ol A component for an dp:b'cal sen.ser according to a first aspect, of the-present invention is an i'ntegrai-moulded component of a shape of cylinder used in concert with the optical sensor. One end of the cylinder accepts the optical sensor and the other end of the cylinder includes a ions portion. for collectmg extraneons lights onto the optical. enôr. ln:ide the cylincfrr a piunihtv of tibs are pmvided at. least three positions along the ckrcunifcrcncc of the cylinder and. each of the plurality of ribs is contiguous to the inside surface of the ions portion and: the inside surface' of the cihnde-r.

[0010] The component for an oplical sensor according to. the present aspect is provided with the pinrality of nhe which are contiguous to the inside su,thice of the lens portion and the inside.suthce of the cylinder. Accordingly the component for an optical sensor can be combined with an optical sensor of a small size, Further, the component for an optical sensor has a simple structure which can be integral-moulded. [ooul

In a component fpr an optical senso according to an et. hodiment f tf he present invention., each of the plurality of ribs has a concave portion and the concave portion is formed such that a position of the concave portion of each of the plurality of ribs determines a dist cc hetwcen th lens pprtio and the optical sçnsor.

EoO 12] A distance between the ien.s portion and the optical sexsor can he determined by combihingthe optcaIsctzsor accordingto the present embodiment with the optical sensor.

[00131 In a component lbr an optical sensor according to another embodiment of the present invention, the expression 0.03AiB.020 (i) is stthfled where A reprsent a total arS of faces of the concave portions which come into contact with a top face of a paekage of the optical sensor and B represents an area of the top face. of the optical sensor.

[00141 IF'urtlhei; the expression DM4 A/EHi 0.15 (2) is preferably satisfied.

[00Th] When tile value of MB is greater than the upper limit of (0, areas in wI'A3ch light is blocked become great and therefore the optical performance will deteriorate. When the value of A/B is greater than the lower limit of (i), the concave portion does not have a sufficient strength and accuracy in distance between the lens portion and the optical sensor cannot be insured. Accordingi3 the optical performance might deteriorate.

[00161 When the expression (2) is satisfied as to the ratio of A/B, the optical perfbnnancc and. strength of the cone eve portion are further improved.: A cottpotient for an optical sensor according to another embodiment of the ].0 present invention is used in concert with a package of an optical sensoi a shape of flit package beng a u-c argutci nafall'leplped, wliercm each Di the pluaa]ity of ribs is provided oneach of at. least two sides of the four sides of the package [00181 When used in concCn with an optical sensorof a package a shape. of which is a rectangular parailelepiped, the component fhr an optical sensor according to the present embodiment is prevented from rotating with respect to the optical sensor.

Eow.91 A component for an optical sensor according to another embodiment. of the present. invention, is need in concert with a package of an optical sensor, a shape of the package being a rectangular paralielepiped, wherein eah of the plurality of ribs is provided on each. of at. least two sides of the thur sides of the package such that a ratio of width of each. rib assigned to an edge between the at least two of thur sides of the. padcage and a light receiving surthce of the package to. length of the edge is 15 9't or more.

10020] When used iti concert; with an optical sensor ala package a shape of which is a iectar galar paxa]elcpiped, I tic component En an OpUcd enox ccoidmg to the present embodiment is prevented from rotating with respect to the optical sensor.

[00211 In a component for an optical sensor according to another embodiment of the piesent in'. enttor, the lcns portton s divided in4o a plurality of lens s4ment' and each of the plurality of ribs is provided along one. of a phirality of boundaries between the piur1ity of lens segments such. that each. of the plurality of ribs is cont:iguous to the lens portion.

(00221 In the conporiert for an optical sensor according to the present embodiment, the ribs are provided, along the boundaries between the lens segments, and therefore effects f blocking of lights cated by the ribs are not great.

[0023] In a component fbr an optical sensor according lii another embodiment of the present invent±on, the optical sensor is a. pyroelectric infrared sensor.

[0(12 41.

The component for an optical sensor according to the present embodiment can be used in concert with a pyroelectric infrared sensor of a sinai]. size.

[1025] A mould for a component for an optical sensor according to a second aspect of the present invention is for an integrali-moulded component of a shape of cylinder used in concert with the optical sensor, One end of the cylinder accepts he..optical sensor and the other end of the cylinder indukles a lens portion for collecting extraneous light onth the. optical sensor. inside the tybtider a.

:25 plurality of ribs are provided at least three positions along the cireurnftirence of the cylinder and each of the plurality of ribs is cofltguuus to the inside surface of the lens portion and the inside surface of the cylindon The lens portion is divided into a plurality of tens segments and each of the plurality.f ribs is provid. d along one of a phn'ahty of boundaries between the plurality of lens segments such that r each of the plurality of ribs is contiguous to the lens portion. A moulding die for shaping iriide surface of the lens portion, i.rside surface of the side of the cylinder and faces of the open end which accepts the optical sensor includes a first moulding the which corresponds to the lens portion for the optical sensor and a.

second moulding die which corresponds to a. periphery of the lens portion for the optical senqn The first moulding die includes a plurahty of dies which correspord. to the plurality of lens segrnerts and mould s'napes for the ribs are provided at an edge of each of the piura]ity of dies. The second moulding die has a through hole into which the first moulding die is inserted for combined use, [0026] In the mould for a component fot an optical sensor according to the present. aspect, the first inflUJ&iuig die which corresponds to the lens portion o:C the optical aensor and the second moulding die which corresponds to the periphery of the lens portion for the optical are separated from each other. Accordingly, components fOr an optical sensor provided with various lenses can be efficiently produced. Furthet; since the first moulding die includes a plurality of dies which correspond to the plurality of lens segments and mould. shapes for the ribs are provided at an edge of each of the plurality of dies, the moulding dies can be machined easily and with a high.. accuracy.

Brief Desaiption of the Drawings Fig I.hows i cross section containing the central axis of a component.

for an optical sensor according to an embodiment of the present invention; Fig. 2 shows a plan view of the coxponcnt. 100 hr an optical Onsor accOrding to the embodiment of the present invention; Fig. 3 is a perspective drawing of the component 100 for an optical sensor according to the embodiment of the present irivcntion Fig-4 hows a plan. view of a xnnoonent lUCiA for an optical sensor according.to another embodiment of the present invention; Fig. 5 is a perspective drawing of the component bOA for an optical sensor according to the embodiment of the present invention; Fig. 6 shows a plan. view of a component bOB for an optical sensor according to another embodiment of the present inve,ition Fig. 7 is a. perspective, drawing of the component. IQOB for an optical sonsor.accordirig to: the emhodiin.ent of the present ixvention Fig. S shows a plait view of a component IOOC for an optical sensor according to another embodiment.of the present invenhon Fig. 9 i a perspective drawing of the component IOOC for an optical sensor accord ng to the embodiment of the present invention; Fig. 10 shows an embodiment of a mould for a component for an. optical sensor piovided with three. ribs; Fig. 11 shows an embodiment of a mould for a component fr an optical sensor provided with six ribs; Fig. 12 shows an example of design of a component lOUD for an optical sensor; Fig, 13 is a perspective drawing of the component 1001) for ala optical sensor; and Fig: 14 shows a convention..I system in which ar. optical sensor and. a componont fhr the optical. sensor are co.mhired.

Mod.e lbr carno ng out: the invention [0028] Fig. 1 shows a cross section co.ntaithng the central axis of a component 1.00 for an optical en.sor according tc an. conbodiment of the present invention. ko29J

Fig. 2 shows a plan view of the, component 100 fr an optical sensor. As shown in Fig. 2, the component 100 for an optical sensor is cjrcuiar in the plan view. The axis winch passes through the center of the. circle and. runs perpendicular to the horizontal plane (the plane of the plan) is the central axiS.

In Fig. 2, 2-axis is defined in the direction of the central axis andX-and Y axes are defined in the. horizontal plane.

[0030] The cwriponont tOO for an optical sensor has an end portion 101 in. which a ns is formed and the side 105. The component 100 for an. optical sensor further includes ribs 103. In the present embodiment, three rits 103 are provided such that they are uiifornily separated en the circutuference. Each of the three ribs 103 is contiguous to the inside hns surface 102 of the end portion 101 in which the lens is. formed and the inside surface of the side 105.. Each of the ribs. 103 is provided with a concave portion 1031, and the concave porton 1081 IS fbnned 4i that it is engaged with a package.201. of an. optea]. sensor. in the text cf specification, the package of tie optical sensor.is called the optical sensor.

In the present embodiment, horizontal cross section (XY croSs section) of the component tOO for an.optical sensor and that of the optical.sensr 201 are circular.

[003 ii At least. three ribs should prefrrabiy he provided to combine and fix the optical sensor and the component for an optical sensot [0032] The comtonent 100 thr an optical eeno. is nade of plastic sudi as polyethylene and polypropylene.

[0033] [n. the present embodiment, the. concave portion 1031 of a rib 103 is formed such that it is engaged with. ti opjk.a'l sensor.201.. Ac.tordiMzl, even vrhcn a projected area onto tie horizontal plane (XY plane) of the inside lens surface 102 is larger than a projected area onto the horizontal plane of the sensor 201, the component 100 for.ai optical Sensor and the sensor 201 tan be combined wxtli each other without using an adapter component or the like.. lurthet by adjusting a position of the concave portion 1031 in the direction of' the central axis.

a distance (distance in Z axis direction) between the tens: and the sensor 201 can.

be determined.

[0034] Fig. 3 is a perspective drawing of the component 100 for an optical sensor, [0035] Fig. 4 shows a pin view of a component IOCA for an optical sensor according to another embodiment of the present invention.

1003b1 lathe present embodiment, the inside lens surface of the component 100A for an optical sensor is divided into six lens segments 102Al 102A2, 102A3 102A4, .102A5 and 102A6 along the cijcmfe.retiai direction. The rcason that the lens. is divided into lens segments is to make different lens segments collect lights at different positions such that each sensor can detect an individual group of lights. Byway of example, when the optical sensor is. a pyroekctnc infrared b sensoi whcn detects 3nfiared a a emitted by objects, d fferent lens segments are used for different sensors, and thus positions and motions of persons can be detected.

10037] Pyroelectric infrared sensors utilize pyroelectrie efl.ect in which electric charge is generated by change of temperature cause.d by infrared rays PyroeIectri.c infrared sensors combined with conwonents for an optical, sensor are used with illumination lamps on external walls for crime prevention, bathrooms air conditioners and the like.

10038] in the present embodiment, the component TOOA for an optcai sensor provided with six ribs 103A1, 103A2, i.0$A3, .103A4, 103A5 and 10$A6. The six ribs 103A1, l03A2, 103A8, 103A4. 108A5 and 103i\ are respectively ptovided along boundaries between the six lens segi ents 102A1, 102A2, 102A3, 1'02A4.

102A5 and 102A6 and at an edge of each of the lens segments. Since the ribs are provided along the boundaries between the lens segments and. at an edge of each of the lens segments, eftcts of blocking of lights caused by the ribs are not great.

[00391 Fig.. 5 is a perspective drawing of the component 100A lot an optical senson [0040] Fig. 6 shows a plan view of a. component 1008 for an optical aensor accorthng to another embodiment of the present intention.

[00411 1.0 In the. present embodiment, the component 1008 for an optical sensor i.e provided, with six ribs I Q313j, 10SD2, 103133., 1Q3B 103B5 and 10386. hi present embcxnment, the horizontal. CiO55 section of the. txnnponen.t 10GB for an.

optical sensor is circUlar. In the present embodiment, the shapc' of an optical sensor 2013 is a rectangular paraliciepiped, and its horizontal cross section is rectangular. Concave portinas of the six ribs 10331, 10332, 103133, 103134, 103135 and 103136 are formed, such that the horizontal faces are engaged with the rectangular top face of the sensor 20113.

[0042] Fig. 7 is a perspective drawing of the component 10DB for an optical sensor.

[00431 Fig. S shows a plan' view of a component I.OOC r an optical sensor according to. another eMbodiment of the present invention.

[00441 in the present embodiment, the component i.OOC for an DtiL!al sensor is provided with six ribs 103C1, 10302, 10303. 10304. 10305 and 1.0306. in the present embodiment. the horizontal cross sedtioi of the component 1000 for an optical sOnsor is rectangular. In the present embpdiment, the shape. of an optical sensor 2010 is a rectanguiar parallelepiped, and its horizontal cross section is rectangular. Concave portions of the six ribs 103(21, 103C2, 103 CS, 103 (24, 103(25 and 103C6 are formed such that the horizontal faces are engaged with the rectangular top face of the sensor 201C.

F 00 451 Thus, the cross section of the component for an optical sensor and that 01 the optical sensor canbe of any shape. [004]

Fig. 9 is a perspectivO drawing of the component 1000 for n optical MlflSOT.

1.0 [004:7] Fig. 10 how an enbodiuicit of a mould for conporent for ap ptca1 sensor Provided with three ribs. The component for an optical. sensor is produced by injection moulding using the mould.

[0048] The mould according to the present embodiment includes Three moulding dies 50L&1. 501A2 and 501A3 lbr the lens segments, a moulding the 601 for the periphery and a moulding die for the outside surface 701. Since the ribs are provided along an edge of each. of the lens segments as described in. connection with Fig.. 3, mould shapes for the ribs are formed at an edge of each of the moulding died 501A1, 501A2 and 501A3 for the lens segments in. the. presett embodiment. [oo49

Since mould shapes for the rIbs are formed at an. edge of each of the moulding dies for the len segmeit.s, the mit:dding dis an he macbind mrg easily than in the. case that shapes for the ribs. are.thrme.d as slots of the moulding dies.

[0050] The three moulding dies 501A1, 501A2 and 501M for the lens segments and the moulding the 601 for the. periphery are aligned such that positions of shapes tbr the ribs are aligned. Then the moulding die for the outside surface 701 is arranged such that it surrounds the moulding dies and injection moulding is carried out.

[oooi] Fig. 11 shows an embodiment of a mould for a conponent for an opica1 sensor provided with six ribs. The component fir an tpt.iea]. sensor is produced by injection moulding. using the mould.

[00521 The mould according to the present enThodiment includes six moulding dies 50181. 50182. 501133. 501134, 50185 and 50186 fin' the lens segments, a moulding die 601 for the periphery ard a moulding die fpr the outside sathce 701.

Since the ribs are provided along an edge of each of the lens.egments as described in connection with Fig. 3, mould shapes for the ribs are formed at an edge of each of the moulding dies 501131, 50182, 501B3, 50114, 50115 and 50186 for the lens segments in the present embodiment.

10053] Since mould shapes for the ribs are thrmed at an edge of each of the moulding dies for the lens segments, the moulding dies can be machined more easily than. in the. case that shapes. fin' the ribs are formed as slats of the moulding dies.

Laos 41 The sixmouiding dies 50181, 50182, 50183, 501B4, 501135 and 50iB6for the lens segments and the moulding die 601 for the periphery are aligned such that positions of shapes for the ribs are aligned. Then the moulding die for th outside surface 701. is arranged such that it. surrounds the moulding dies and injection mould is canted out.

By using the mould described above, a conponent for an optical senso; which has the end portion in which, a lens is thrmed, the side and the.rib.s can be integralmoulded through injection moulding.

[0056] It should be noted that moulding die 601 icr the periphery and the moulding die for the outside surface 701 can be comTnonly used for different.

5. moulding cUes for len segments. Since moulding dies for the lens segments and maui.ding die for the periphery are separated, components for an optical sensor provided with various lenses designed for variOus. applications can be efficiently produced. kx7]

Fig. 12 shows an example of design of a.compokient for an optical sensor.

Fig. 12(a), Fig. 120). Fig. 12(0) and Fig. 1:2(d) are reapedively a top view, a side vievv. a bottom view and a cr{mJs'sec aonal viewalong line A-A in the top view.

[00581 As shown iii Fig, 12(c), the component for ai optical sensor 1.001) is provided with four ribs 10313 formed along the boundaries between the four lens segments 10111 Each of the four lens segments 1011) has an indIvidual shape.

The four ribs lO3D are. farmed such that they are engaged with the optical sensor.

[0059] in the psent example, the total area A of the faces of the concave portions which come into contact wth the. top face of the optical seSot is 0.95 square mithrneters. The area B of the top face of the optical sensor is 221 square millimeters. Accordingly the ratio A/B is 0.043. Furthez the length of one of the edges of the package of the optical. eensor between the light receiving surface nd the sides is 47 miLlimeters. The width of each rib assigned to each edge is 0;9:5 millimeters. Accordingly, the ratio of the width to the length of eaci.h edge is 20.2% [00601 Fig. 1$ is a perspective drawing of the. component 1001) for an optical.

sensor, 13.

[oust] Components for an optical sens)r according to the present. invention can be widely used also for optical sensors such as photoelectric sensors.

Photoelectric sensors are widely used to detect presence of an object and ±hr other purposes.

Eplanations of numerals t00621 100; bOA, 10013, IOOC and IDOD component for an optical sensor bland. biD end. porUor of the cvlthder including a 1en lO inside lens surMce af the nd ponioxa ofihe cylinder 102A1. 102*A2. 102A3, i.02A4, i.02A5 and 102A6 lens segments 103 1O3A1, 103A2, JOJAJ, 103A, 10 Aa IOJAG 103131 l03B, 103B3 10334 lOaDS., 103136, 10301. 105C2, 10803, 10304, 10305, 1030 and 103!) ribs 105 side 501A1, 501A2, 501A3, 501B1, 501132, 501133, 50iB4, bUlBS and 501136 moulding dies for the lens segments 601 moulding the for the periphery 70l. moulding the for the outside surface