WO2015032089A1

WO2015032089A1 - Shock sensor and electronic device

Info

Publication number: WO2015032089A1
Application number: PCT/CN2013/083129
Authority: WO
Inventors: James Thornton; Xia Chen
Original assignee: Robert Bosch Gmbh
Priority date: 2013-09-09
Filing date: 2013-09-09
Publication date: 2015-03-12
Also published as: CN105519231A; CN105519231B; AU2013400005B2; AU2013400005A1

Abstract

A shock sensor comprises a base, a PCBA fixed to the base, the PCBA comprising a shock detecting device for sensing shocks and a light emitting element for emitting a light to indicate that a shock has been sensed by the shock detecting device, an enclosure assembled to the base for accommodating the PCBA, and a light transmitting member extending through the enclosure for transmitting the light emitted from the light emitting element to outside. The light transmitting member is provided with a locking structure for releasably locking the enclosure to the base. Ingress protection standards can be met by the shock sensor with a simplified structure.

Description

Shock Sensor and Electronic Device

Technical Field

The disclosure relates to an electronic device, in particular a shock sensor, comprising a light transmitting member having a locking structure.

Background Art

Many public and household facilities, such as automobiles, motorcycles, automatic teller machines, building gates or the like, are equipped with shock sensors. When a facility is attacked, its shock sensor can sense the attack and trigger an indicating or alarming signal, such as a video signal.

A typical shock sensor comprises a base, a printed circuit board assembly (PCBA) carried by the base, and an enclosure assembled to the base to protect the PCBA. The PCBA comprises a light emitting diode (LED) as an indicating or alarming device for indicating the state that an attack has been sensed. A light pipe is generally used for transmitting light emitted from the LED to outside so that the state of the LED is noticeable. The light pipe has an inner end facing towards the LED and an outer end extending through the enclosure and exposed outside.

The enclosure has to be openable for adjustment. Thus, a screw is generally used for locking the enclosure to the base. Meanwhile, the shock sensor shall meet the ingress protection standards of the International Electrotechnical Commission (IEC), like IP43. For example, the enclosure needs to protect the PCBA against water (IPX3), as well as to protect the PCBA against dust (IP4X). However, when the enclosure is penetrated by both the screw and the light pipe, it is not easy for the shock sensor to pass IP43.

Summary of the Invention

The disclosure is aimed at providing a shock sensor which can meet the requirement of ingress protection standards in a simple manner.

For this end, the disclosure in one aspect provides a shock sensor which comprises a base, a PCBA fixed to the base, the PCBA comprising a shock detecting device for sensing shocks and a light emitting element for emitting a light to indicate that a shock has been sensed by the shock detecting device, an enclosure assembled to the base for accommodating the PCBA; and a light transmitting member extending through the enclosure for transmitting the light emitted from the light emitting element to outside, wherein the light transmitting member is provided with a locking structure for releasably locking the enclosure to the base.

According to a preferred embodiment of the disclosure, the shock sensor further comprises a PCBA cover which is clamped to the PCBA for protecting at least a portion of the PCBA, wherein the PCBA cover is an individual member clamped to the PCBA or an integral portion of the base into which the PCBA is inserted.

According to a preferred embodiment of the disclosure, the light emitting element comprises an LED, and the light transmitting member comprises a light pipe having an inner end facing towards the light emitting element and releasably locked to the PCBA cover and an outer end disposed in the enclosure and exposed to outside.

According to a preferred embodiment of the disclosure, the light pipe is rotatable between a locking position in which the enclosure is locked to the base and an unlocking position in which the enclosure is allowed to be removed from the base.

According to a preferred embodiment of the disclosure, the outer end of the light pipe is engaged in the enclosure by form fit, and the inner end of the light pipe is provided with at least one cam which is releasably locked to the PCBA cover by a cam action.

According to a preferred embodiment of the disclosure, the cam is configured to drive the light pipe to move towards the base when the light pipe is rotated from the unlocking position to the locking position.

According to a preferred embodiment of the disclosure, the enclosure and/or the PCBA cover is provided with a stop for preventing the light pipe from being rotated beyond the locking position and/or the unlocking position.

According to a preferred embodiment of the disclosure, the light pipe is provided with an orientation indicator on an outer end surface of it for indicating the angular orientation of the light pipe, the orientation indicator preferably comprising a driving socket into which a tool for driving the light pipe to rotate is insertable.

According to a preferred embodiment of the disclosure, the enclosure is formed with recognizable marks which are aligned with the orientation indicator when the light pipe is in its locking and unlocking positions respectively.

According to a preferred embodiment of the disclosure, the shock sensor further comprises a sealing member disposed between the light pipe and the enclosure.

According to a preferred embodiment of the disclosure, the shock sensor further comprises an engaging structure provided between the enclosure and the base at a longitudinal location different from that of the light transmitting member.

According to a preferred embodiment of the disclosure, the light emitting element is normally turned off when no shock over a predetermined threshold is detected, and is turned on when a shock over the threshold is detected; alternatively, the light emitting element normally emits a light of a first color when no shock over a predetermined threshold is detected, and emits a second color that is different from the first color when a shock over the threshold is detected.

The disclosure in another aspect provides an electronic device, in particular a sensor, which comprises a first part and a second part, which are assembled together to define an accommodating space therebetween, a light emitting element disposed in the accommodating space for emitting a light to indicate a state of the electronic device, and a light transmitting member extending through one of the first and second parts for transmitting the light emitted from the light emitting element to outside, wherein the light transmitting member is provided with a locking structure for releasably locking the first and second parts together.

The shock sensor or the electronic device of the disclosure, which comprises a light transmitting member, such as a light pipe, having a locking function, can meet the requirement of ingress protection standards more easily.

Brief Description of the Drawings

The disclosure will be further understood by reading the following detailed description with reference to the drawings in which:

Figure 1 is an exploded perspective view of a shock sensor according to a preferred embodiment of the disclosure;

Figure 2 is an exploded perspective view of the shock sensor showing a clamped state of a PCBA cover of the shock sensor;

Figure 3 is a bottom perspective view of an enclosure of the shock sensor;

Figure 4 is a partial exploded perspective view of the shock sensor showing an engaging structure at an end thereof;

Figure 5 is a perspective view of the shock sensor in an assembled state;

Figure 6 is a sectional view of the assembled shock sensor taken in a longitudinal direction thereof;

Figure 7 is a partial sectional view of the shock sensor showing a light pipe and structures surrounding it;

Figure 8 is a perspective view of the light pipe;

Figure 9 is a top perspective view of the shock sensor, with the enclosure removed, showing a stopping function of the PCBA cover to the light pipe; and

Figure 10 is a bottom perspective view of the enclosure with the light pipe showing a stopping function of the enclosure to the light pipe.

Detailed Description of Preferred Embodiments

Now a shock sensor according to a preferred embodiment of the disclosure will be described. The shock sensor may be incorporated in a facility for detecting an attack applied to the facility and triggering an alarming signal when the attack is determined as over a certain threshold.

As shown in Figure 1, a shock sensor mainly comprises a base 2, a PCBA 4 carried by the base, a PCBA cover 6 assembled to the PCBA 4, covering a main portion of the PCBA 4, and an enclosure 8 attached to the base 2 to form a sealed space in which the PCBA 4 and the PCBA cover 6 is accommodated.

The base 2 is formed as a unitary piece, comprising a substantially rectangular bottom plate 2a, and transversely opposite side walls 2b and longitudinally opposite end walls 2c extending substantially vertically from the bottom plate 2a.

The PCBA 4 is arranged in a space delimited by the side walls 2b and the end walls 2c. The PCBA 4 comprises a substrate having a functional area and a terminal area, the two areas being longitudinally adjacent to each other. The functional area carries thereon functional components, such as a micro-processor, a shock detecting device, sensitivity adjusting means and an alarm device. The functions and structures of these functional components are well known in the art. The functional area, with the functional components carried on it, is covered and protected by the PCBA cover 6.

The alarm device is in the form of an LED 10 for indicating the condition when a shock is detected by the shock detecting device. The LED 10 may be set in deactivated and activated states, so that it is deactivated when no shock is detected and is activated to emit an indicating light when a shock is detected. Alternatively, the LED 10 is always activated when the shock sensor is turned on to indicate the normal operation of the shock sensor, and changes the color of the light emitted from it when a shock is detected. In other words, the LED 10 emits light in a first color, for example, green, in the normal operation of the shock sensor, and emits light in a second color, for example, red, when a shock is detected.

Terminals 12, for power supply and data transmission, are mounted to the terminal area of the substrate of the PCBA 4 and are not covered by the PCBA cover 6.

The PCBA cover 6 is formed as a unitary piece, comprising a plate-like main portion 6a which is substantially parallel with the bottom plate 2a of the base 2 when the PCBA cover 6 is assembled to the PCBA 4, vertical portions 6b which extend substantially perpendicularly from the main portion 6a and abut against the edge of the PCBA 4 in the assembled state, and clamping legs 6c which also extend substantially perpendicularly from the main portion 6a and can be engaged with corresponding edge portions, for example, cutouts 4a, of the substrate of the PCBA 4 to fixedly assemble the PCBA cover 6 to the PCBA 4.

Once the PCBA cover 6 is assembled to the PCBA 4 by the clamping legs 6c, the resulted assembly can be then assembled to the base 2. Figure 2 shows the state in which the assembly of the PCBA cover 6 and the PCBA 4 is assembled to the base 2. The terminals 12 are omitted in this and other figures for clarity. In this state, the substrate of the PCBA 4 is clamped to the base 2 by a clamping features of the base 2, for example, hooks 14a and 14b which hooked onto longitudinally opposite edge portions of the substrate.

The enclosure 8 is formed as a unitary piece, comprising a top plate 8a which is substantially parallel with the bottom plate 2a when the enclosure is attached to the base 2, transversely opposite side walls 8b and longitudinally opposite end walls 8c extending substantially vertically from the top plate 8a. One or both of the end walls 8c may be slightly oblique outwardly for facilitating the attachment of the enclosure 8 to the base 2.

A first longitudinal end (the end near the terminals 12) of the enclosure 8 is attached to a corresponding first end of the base 2 by an engaging structure. The engaging structure may comprise one or more protrusions (two in the illustrated embodiment) 16 formed on the end wall 8c at the first end of the enclosure 8, as can be seen in Figures 3 and 4, and corresponding recesses 18 formed in the end wall 2c at the first end of the base 2, as can be seen in Figures 1, 2 and 4. By engaging the protrusions into the recesses 18, as shown in Figure 4, the first end of the enclosure 8 is locked to the first end of the base 2.

An elastic plug 20, having a cable passage 20a therethrough, is disposed between the first ends of the enclosure 8 and the base 2. A cable (not shown) of the shock sensor, which is connected to the terminals 12, extends through the cable passage 20a to outside. For arranging the elastic plug 20, the end wall 2c at the first end of the base 2 is formed with an undercut 2d, and the end wall 8c at the first end of the enclosure 8 is formed with an undercut 8d. The elastic plug 20 forms sealing for the cable.

For transmitting light emitted from the LED 10 to outside, a light transmitting member in the form of a light pipe 22 is provided. The light pipe 22 has a substantially cylindrical shape defining a central axis substantially perpendicular to the top plate 8a and the bottom plate 2a. The light pipe 22 has an inner end facing towards the LED 10 and an outer end located within a socket 8e formed in the top plate 8a, the outer surface of the outer end being preferably substantially flush with the outer surface of the top plate 8a. The light from the LED 10 is transmitted through the light pipe 22 from its inner end to its outer end so that the state of the LED 10 (on/off, and/or color of it) can be seen from outside.

The LED 10 is so arranged on the PCBA 4 that it aligns substantially to a longitudinal central axis of the shock sensor in a transverse direction and is closer to the second longitudinal end of the shock sensor in a longitudinal direction than to the first longitudinal end of the shock sensor.

The light pipe 22 according to the disclosure has double functions, a first function of transmitting the light of the LED 10 and a second function of locking the enclosure 8 to the PCBA cover 6 and thus to the base 2 at a longitudinal location that is different from that of the engaging structure. By means of the locking functions provided by the light pipe 22 and the above-mentioned engaging structure at different longitudinal locations, the enclosure 8 is fixedly attached to the base 2, so that a completed shock sensor is formed.

The light pipe 22 can be rotated around its central axis in an unlocking direction and a locking direction so that the light pipe 22 can be brought to an unlocking position and a locking position respectively. When the shock sensor is in an assembled state and the light pipe 22 is in the unlocking position, as shown in Figure 5, the light pipe 22 is disengaged from the PCBA cover 6 to allow the enclosure 8 to be removed from the base 2. On the other hand, when the shock sensor is in an assembled state and the light pipe 22 is in the locking position, the light pipe 22 is engaged with the PCBA cover 6 to lock the enclosure 8 to the base 2.

As can be seen from the longitudinal sectional view of Figure 6 and more clearly from the partial sectional view of Figure 7, the inner end (the lower end in the figures) of the light pipe 22 is engaged with PCBA cover 6 and the outer end (the upper end in the figures) of the light pipe 22 is engaged with the enclosure 8. Further, the bottom plate 2a is formed with screw holes 2e through which screws can be inserted through to fix the shock sensor to a facility.

As also can be seen in Figure 7, in the assembled state of the shock sensor, a rib 8f extending from the inner surface of the top plate 8a of the enclosure 8 abuts against ridges 6d formed on the outer surface of the main portion 6a of the PCBA cover 6.

The detailed structure of the light pipe 22 is shown in Figure 8. As can be seen, the light pipe 22 is formed as a unitary piece of a light transmitting material, comprising an outer cylindrical portion 40 forming the outer end of light pipe 22, a middle cylindrical portion 42, a circular recess 44 being formed between the outer cylindrical portion 40 and the middle cylindrical portion 42, and a inner cam portion 46 forming the inner end of light pipe 22, a substantially circular recess 48 being formed between the middle cylindrical portion 42 and the inner cam portion 46.

An orientation indicator 50 is formed on the outer surface of the outer cylindrical portion 40, i.e., the outer end surface of the light pipe 22, for indicating the angular orientation of the light pipe 22. The orientation indicator 50 may be in any suitable form that is easy to be recognized by those skilled in the art. In the illustrated embodiment, the orientation indicator 50 is an arrow comprising an arrow stem 50a and an arrow head 50b. The arrow head 50b may be convexed on the outer surface of the outer cylindrical portion 40. An elongated driving socket may be formed inwardly from the outer surface of the outer cylindrical portion 40 along the arrow stem 50a, preferably extending into a portion of the arrow head 50b. The elongated driving socket is configured so that a tool, like a flat-tip screw driver, can be inserted thereinto to drive the light pipe 22 to rotate around its central axis.

A pair of diametrically opposite lugs 52 are formed on middle to inner parts of the outer periphery of the middle cylindrical portion 42. The lugs 52 each extend along the axial direction, having an inner edge that is close to or substantially flush with the inner edge of the middle cylindrical portion 42 and an outer edge which is separated from the outer edge of the middle cylindrical portion 42 by a distance.

The inner cam portion 46 comprises a pair of diametrically opposite cams, which may be located inward of the pair of opposite lugs 52, or be angularly offset therefrom.

Each cam comprises a cam surface that faces substantially outwardly in the axial direction, or towards the outer cylindrical portion 40. The cam surface comprises a flat part 46a which is substantially perpendicular to the axis of the light pipe 22 and a curved portion 46b continued with the flat part 46a, the axial distance between a portion on the curved portion 46b and the outer cylindrical portion 40 being decreased gradually as the portion is angularly away from the flat part 46a. The cam surfaces of the pair of cams are rotationally symmetrical with each other.

The inner cam portion 46 further comprises a pair of flat surfaces 46c which are parallel with each other and parallel to the central axis of the light pipe 22 and are formed by cutting away the material of the inner cam portion 46 between the two cams. The distance between the pair of flat surfaces 46c, or the width of the inner cam portion 46, is smaller than the diameter or the length of the inner cam portion 46. A chamfer 46d may be formed between each flat part 46a and the neighboring flat surface 46c.

The diameter of the middle cylindrical portion 42 is smaller than that of the outer cylindrical portion 40, and the diameter of the inner cam portion 46 is equal to or smaller than the diameter of the middle cylindrical portion 42.

The enclosure 8 is formed with marks for recognizing the orientation of the light pipe 22. In the illustrated embodiment, the marks for recognizing comprises an unlocked mark 56a and a locked mark 56b, both formed on the outer surface of the enclosure 8. The unlocked mark 56a and the locked mark 56b are separated from each other by an angle corresponding to the separation angle (preferably 90°) between the unlocking and locking positions of the light pipe 22. The orientation indicator 50 points to the unlocked mark 56a when the light pipe 22 is in the unlocking position as shown in Figure 5 as well as in Figures 6 and 7, and the orientation indicator 50 points to the locked mark 56b when the light pipe 22 is in the locking position.

For engaging with the inner end of the light pipe 22, the PCBA cover 6 comprises a pair of biasing bars 62 on the outer surface of its main portion 6a and a slot 64 between the pair of biasing bars 62 through the main portion 6a. The biasing bars 62 and the slot 64 are parallel with each other in the longitudinal direction of the shock sensor, and the slot 64 is at a location outward of the LED 10, as can be seen in Figures 1 and 7. Further, each of the biasing bars 62 is formed with an outwardly protruding stop 62a, the two stops 62a being offset with respect to each other in the longitudinal direction, as can be seen in Figure 2.

Further, for engaging with the outer end of the light pipe 22, the enclosure comprises a cylindrical tube portion 8g extending from the inner surface of the top plate 8a of the enclosure 8 and defining the socket 8e therein, and a bottom 8h connected to the inner edge of the tube portion 8g and comprising a through hole therein.

The socket 8e has an inner diameter slightly larger than the diameter of the outer cylindrical portion 40 of the light pipe 22 to allow the outer cylindrical portion 40 to be accommodated therein. The through hole in the bottom 8h has an inner diameter slightly larger than the diameter of the middle cylindrical portion 42 of the light pipe 22 but smaller than that of the outer cylindrical portion 40, so that the middle cylindrical portion 42 is allowed to be inserted through the through hole while the outer cylindrical portion 40 is not. In this way, the outer cylindrical portion 40 is kept in the socket 8e. An O-ring 60 is disposed in the circular recess 44 between the outer cylindrical portion 40 and the middle cylindrical portion 42 for sealing the interface between the light pipe 22 and the enclosure 8.

It is noted that the middle cylindrical portion 42 has a pair of lugs 52 thereon. For allowing the lugs 52 to pass through the bottom 8h with the middle cylindrical portion 42, the bottom 8h is formed with a pair of cutouts 8i, one of which can be seen in Figure 10. The cutouts 8i are located at locations that are each offset by an acute angle from the longitudinal central axis of the shock sensor in the unlocking direction of the light pipe 22, so that the middle cylindrical portion 42 and the pair of lugs 52 can pass through the through hole and the cutouts 8i in the bottom 8h respectively. Then, the light pipe 22 can be rotated in the unlocking direction through an angle that equals to 180° minus the offset angle to come into the unlocking position.

In the unlocking position, the inner cam portion 46 of the light pipe 22 is aligned with the slot 64 in the main portion 6a of the PCBA cover 6. The slot 64 has a width that is slightly larger than the width of the inner cam portion 46 but smaller than the length of the inner cam portion 46. Thus, the inner cam portion 46 is allowed to be inserted through the slot 64 to a position slightly inward of the inner surface of the biasing bars 62. In this state, if the light pipe 22 is rotated in the locking direction, the cam surfaces of the inner cam portion 46, especially the curved portion 46b, will contact the inner surface of the biasing bars 62 to create a cam action. Under the action of the cam action, the light pipe 22 is pulled inwardly and the O-ring 60 is compressed between the outer cylindrical portion 40 and the bottom 8h. Ultimately, the light pipe 22 reaches the locking position to lock the enclosure 8 to the PCBA cover 6 and thus to the base 2.

In the assembled state of the shock sensor, the light pipe 22 can be prevent from being rotated further in the locking direction beyond the locking position and from being rotated further in the unlocking direction beyond the unlocking position.

Specifically, if the light pipe 22 is rotated further in the locking direction from the locking position, the lugs 52 on the middle cylindrical portion 42 will contact and be stopped by the stops 62a on the biasing bars 62 respectively, as can be seen in Figure 9. On the other hand, if the light pipe 22 is rotated further in the unlocking direction from the unlocking position, the lugs 52 will contact and be stopped by the stops 8j formed on the inner surface of the bottom 8h respectively, as can be seen in Figure 10. In this way, the light pipe 22 is restricted to be rotated between the locking and unlocking positions.

It is appreciated that the features described above can be modified within the scope of the disclosure.

For example, the number of the cams of the light pipe (and also the number of the biasing bars) is not restricted to two; rather, it may be one or more.

Similarly, the number of the lugs (and also the number of the stops on the PCBA cover and the number of the stops on the enclosure) is not restricted to two; rather, it may be one or more.

Further, the engaging structure between the enclosure and the base may be formed at other longitudinal locations of the shock sensor rather than the first ends of the enclosure and the base, only if the engaging structure is at different longitudinal location from that of the light pipe.

Further, the driving socket formed in the outer end surface of the light pipe may be formed so that other tools or more than one tool can be inserted into it.

Further, the PCBA cover may be formed as an integral portion (a PCBA covering portion) of the base into which the PCBA is inserted.

Alternatively, the PCBA cover may be omitted, in which case the light pipe may be engaged with a portion of the base directly to lock the enclosure to the base.

According to the disclosure, a light pipe which transmits light from an LED of a shock sensor is incorporated with a locking function, so that the screw for locking the enclosure as used in the prior art is omitted. Meanwhile, a sealing member (O-ring) is disposed between the light pipe and the enclosure to improve water proof performance of the enclosure in a simple manner.

In this way, the requirement of Ingress protection standards, such as IP43, can be met easily by the shock sensor.

It is appreciated that the concept of the disclosure is applicable not only in shock sensors, but also in other electronic devices, like various other types of sensors. Such an electronic device may comprise a first part and a second part, which are assembled together to define an accommodating space therebetween, a light emitting element disposed in the accommodating space for emitting a light to indicate a state of the electronic device, and a light transmitting member extending through one of the first and second parts for transmitting the light emitted from the light emitting element to outside. The light transmitting member is provided with a locking structure for releasably locking the first and second parts together.

While certain embodiments have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the disclosure. The attached claims and their equivalents are intended to cover all the modifications, substitutions and changes as would fall within the scope and spirit of the disclosure.

Claims

CLAIMS:

1. A shock sensor comprising:

a base;

a PCBA fixed to the base, the PCBA comprising a shock detecting device for sensing shocks and a light emitting element for emitting a light to indicate that a shock has been sensed by the shock detecting device;

an enclosure assembled to the base for accommodating the PCBA; and

a light transmitting member extending through the enclosure for transmitting the light emitted from the light emitting element to outside;

wherein the light transmitting member is provided with a locking structure for releasably locking the enclosure to the base.

2. The shock sensor of claim 1, further comprising a PCBA cover which is clamped to the PCBA for protecting at least a portion of the PCBA;

wherein the PCBA cover is an individual member clamped to the PCBA or an integral portion of the base into which the PCBA is inserted.

3. The shock sensor of claim 1 or 2, wherein the light emitting element comprises an LED, and the light transmitting member comprises a light pipe having an inner end facing towards the light emitting element and releasably locked to the PCBA cover and an outer end disposed in the enclosure and exposed to outside.

4. The shock sensor of claim 3, wherein the light pipe is rotatable between a locking position in which the enclosure is locked to the base and an unlocking position in which the enclosure is allowed to be removed from the base;

wherein the outer end of the light pipe is engaged in the enclosure by form fit; and wherein the inner end of the light pipe is provided with at least one cam which is releasably locked to the PCBA cover by a cam action.

5. The shock sensor of claim 4, wherein the cam is configured to drive the light pipe to move towards the base when the light pipe is rotated from the unlocking position to the locking position.

6. The shock sensor of claim 4 or 5, wherein the enclosure and/or the PCBA cover is provided with a stop for preventing the light pipe from being rotated beyond the locking position and/or the unlocking position.

7. The shock sensor of any one of claims 4 to 6, wherein the light pipe is provided with an orientation indicator on an outer end surface of it for indicating the angular orientation of the light pipe, the orientation indicator preferably comprising a driving socket into which a tool for driving the light pipe to rotate is insertable; and

wherein the enclosure is formed with recognizable marks which are aligned with the orientation indicator when the light pipe is in its locking and unlocking positions respectively.

8. The shock sensor of any one of claims 3 to 7, further comprising at least one of:

a sealing member disposed between the light pipe and the enclosure; and

an engaging structure provided between the enclosure and the base at a longitudinal location different from that of the light transmitting member.

9. The shock sensor of any one of claims 1 to 8, wherein the light emitting element is normally turned off when no shock over a predetermined threshold is detected, and is turned on when a shock over the threshold is detected; alternatively, the light emitting element normally emits a light of a first color when no shock over a predetermined threshold is detected, and emits a second color that is different from the first color when a shock over the threshold is detected.

10. An electronic device, in particular a sensor, comprising:

a first part and a second part, which are assembled together to define an accommodating space therebetween;

a light emitting element disposed in the accommodating space for emitting a light to indicate a state of the electronic device; and

a light transmitting member extending through one of the first and second parts for transmitting the light emitted from the light emitting element to outside;

wherein the light transmitting member is provided with a locking structure for releasably locking the first and second parts together.