CN108074359B

CN108074359B - Alarm device

Info

Publication number: CN108074359B
Application number: CN201611001936.1A
Authority: CN
Inventors: 林绍忱; 罗京宜
Original assignee: Siemens Schweiz AG
Current assignee: Siemens Schweiz AG
Priority date: 2016-11-11
Filing date: 2016-11-11
Publication date: 2020-12-04
Anticipated expiration: 2036-11-11
Also published as: CN108074359A; EP3321898A1; PL3321898T3; EP3321898B1

Abstract

The invention provides an alarm suitable for wall mounting, which comprises: a support plate (21); at least three light-emitting units (23) arranged on the support plate (21) and spaced apart from each other along a substantially semicircular arc line (C); -at least one reflector cup (25) fixable to the support plate (21) and each adapted to receive at least one of the lighting units (23), the reflector cups (25) extending substantially or being arranged in a semicircular ring shape, the inner surface of the reflector cup being a reflecting surface and being configured to reflect light emitted by the lighting unit (23) towards a cuboidal optical covering space (V), wherein the alarm is placed in a central position of a top edge of the optical covering space (V).

Description

Alarm device

Technical Field

The present invention relates generally to notification devices for alerting of the occurrence of an emergency event, and more particularly to Visual notification devices, also known as Visual Alarm Devices (VADs) or Optical alarm devices (Optical alarm devices), used in fire protection systems.

Background

Visual alarms are widely used in fire alarm systems to provide visual warning indications, such as high intensity stroboscopic lights, to field personnel in the event of an emergency. Usually, the Visual Alarm (VAD) is connected to a Control device (Control Panel) via a Field Line (Field Line) or a wireless link. When an emergency situation is detected (e.g. a fire), the control device can trigger the VAD via the field line so that the VAD emits a high-intensity warning light visible to the human eye to prompt field personnel to evacuate the hazardous area in time.

In general, VADs can be mounted on ceilings (referred to as "ceiling mounted") or walls (referred to as "wall mounted"). Fig. 1 schematically illustrates a schematic view of a wall-mounted VAD 100. As shown in fig. 1, the VAD 100 is mounted on a wall W and is capable of illuminating a generally cubic or rectangular parallelepiped space V, wherein the VAD 100 is located at a midpoint of a top edge of the cubic space V. The light intensity distribution on the various surfaces of this cubic space V needs to meet the requirements of the relevant fire protection standards. The cubic space V is usually described by (X, Y), where X denotes the installation height of the VAD 100 from the ground, e.g. 2.4m, Y denotes the farthest distance that the VAD light can reach in the direction perpendicular to the wall surface, and the range that the VAD light can cover in the direction parallel to the wall surface, e.g. Y equals 10 m. Thus, the cubic space V is also called an optical Coverage space (Coverage Volume), which is also a space specified in the relevant fire standards that needs to be illuminated by the warning light. When the VAD 100 is actually installed, the alarming effect of the VAD can be ensured as long as the room where the VAD is installed is smaller than the optical coverage space V.

As Light Emitting Diode (LED) technology matures, LED chips are increasingly being used as light sources in VADs. In order to meet the requirements of the relevant standards for VAD light intensity distributions, it is generally necessary to use high-intensity LED chips, whose power consumption is also high.

Therefore, it is necessary to provide a VAD using an LED chip as a light source, which can reduce the performance requirement of a single LED chip while meeting the relevant standard requirements.

Disclosure of Invention

It is an object of the present invention to provide a Visual Alarm (VAD) suitable for wall mounting that can use a low power LED chip as a light source.

According to one aspect of the present invention, there is provided an alarm adapted for wall mounting, comprising: a support plate; at least three light emitting units disposed on the support plate and arranged spaced apart from each other along a substantially semicircular arc line; at least one reflector cup capable of being fixed on the supporting plate and each adapted to accommodate at least one of the lighting units, the reflector cups extending substantially or arranged in a semicircular ring shape, the inner surface of the reflector cup being a reflecting surface and configured to reflect light emitted by the lighting unit towards a substantially cuboidal optical cover space, wherein the equivalent optical center of the alarm is placed in the center of a top edge of the optical cover space.

Preferably, if there are two or more reflectors in the alarm, the adjacent two reflectors separate the light emitting units in the two reflectors from each other. Alternatively, the interval between every two adjacent light emitting units is equal. Optionally, the interval between each two adjacent light emitting units is gradually changed. Optionally, each light emitting unit includes two or more LED chips.

The alarm employs a plurality of discrete light emitting units arranged substantially along a semicircular arc at a spacing from one another. With this distributed arrangement, the plurality of light emitting units can contribute to the light intensity output of the alarm together, which reduces the requirement for the light intensity output of each light emitting unit. If necessary, a plurality of light emitting units may also be arranged to provide a higher luminous flux for the purpose of covering a larger space. Meanwhile, the light emitting units are arranged near two end points of the semicircular arc line and matched with a reflecting structure such as a reflecting cup, so that the light intensity distribution close to the top surface of the light coverage space V can be improved, and the requirements of relevant standards can be met more easily. Thus, the example shown in fig. 2 can use a light emitting unit with lower power consumption and a light intensity distribution capable of satisfying the standard requirements. Furthermore, the light reflecting cup can reflect the light emitted by each light emitting unit towards the light covering space. The design of the reflecting cup can well meet the requirement of the light intensity output of the alarm in the specified direction, which is provided by the relevant standards, and effectively compensate the light intensity distribution.

Preferably, each of the light reflecting cups is disposed to partially surround at least one of the light emitting units disposed therein, and the light exit openings of the light reflecting cups are disposed on the outer periphery of the semicircular ring. Preferably, the inner surface of the reflector cup is concave, the reflector cup has first and second generally opposed reflective portions and the light emitting unit is disposed between the first and second reflective portions, wherein at least one of the first and second reflective portions is inclined in a direction away from the light emitting unit. The first and second reflecting portions are designed to increase the light intensity distribution area of the output light of the light emitting unit, thereby compensating for the light intensity distribution in the region outside the straight irradiation range of the light emitting unit. In other words, the two reflecting portions can reflect more energy emitted by the light emitting unit toward a specified direction (light coverage space V) as a standard.

Optionally, the first and second reflective portions of the reflector cup near the midpoint of the semicircular ring are each inclined toward a direction away from the light emitting unit. Optionally, for the light reflecting cup located near the end point of the semicircular ring, the first reflecting portion near the end point of the semicircular ring is inclined towards the light emitting unit, and the second reflecting portion is inclined away from the light emitting unit.

Preferably, the first reflecting portion or the second reflecting portion of at least one reflector cup includes two or more sub-reflecting portions adjacent to each other, and each sub-reflecting portion is a reflecting surface of a conical curved surface. The adoption of the plurality of sub-reflecting surfaces can more effectively set the curvature or orientation of the sub-reflecting surfaces aiming at the incident light with different angles, thereby improving the reflecting efficiency.

Preferably, each of the reflector cups further comprises a third reflective portion adjacent to the first and second reflective portions and facing the light emitting unit contained therein, the third reflective portion being concave. Preferably, the third reflecting portion includes at least two sub reflecting portions adjacent to each other, each of which is a reflecting surface of a conic surface type. The third reflecting part can reflect the light rays emitted by the light emitting unit and back to the optical covering space towards the optical covering space.

Preferably, each of the light reflecting cups further includes a first auxiliary reflecting portion disposed at an edge of the light reflecting cup above the light emitting unit, and the first auxiliary reflecting portion extends to have a concave surface, and preferably, the first auxiliary reflecting portion has a plurality of concave surfaces corresponding to the number and positions of the LED chips. The auxiliary reflecting portion can enhance the light intensity distribution in the region near the top surface of the light covered space.

Optionally, the alarm further includes a transparent cover at least covering the light emitting unit and the reflective cup, and the transparent cover is provided with at least one prism portion capable of guiding the light emitted by the light emitting unit to scatter toward the optical covering space. Preferably, the at least one prism portion includes at least one prism portion extending in a circumferential direction of the transparent cover, or includes at least one prism portion extending in a direction perpendicular to the circumferential direction of the transparent cover. The prism part is arranged on the transparent cover, so that the diffusion angle of the light emitted by the light-emitting unit can be further enlarged.

Preferably, the alarm further comprises a replaceable housing which at least partially covers the transparent cover, and at least one of the light emitting unit and the reflector cup is removable. Preferably, the replaceable housing is a first housing having a semicircular opening adapted to expose the light emitting unit and the reflector cup. The replaceable housing may also be a housing that completely covers the transparent cover. By adopting the replaceable shell and the detachable luminous unit or the detachable reflection cup, two products of the audible and visual alarm and the audible and visual alarm can be obtained on the same basic structure without being changed too much. The design is convenient for production and processing, and therefore, the production cost is reduced.

The above features, technical features, advantages and modes of realisation of the device will be further explained in the following, in a clearly understandable manner, with reference to the accompanying drawings, illustrating preferred embodiments.

Drawings

The following drawings are only schematic illustrations and explanations of the present invention, and do not limit the scope of the present invention.

Fig. 1 schematically shows an optical coverage space of a wall-mounted VAD.

Fig. 2 shows a schematic diagram of a VAD according to an embodiment of the invention.

Fig. 3 illustrates an exploded perspective view of the VAD shown in fig. 2.

Fig. 4A to 4C schematically show the arrangement of light sources in a VAD according to another embodiment of the present invention.

Fig. 5A and 5B show a schematic diagram of a reflector cup in a VAD according to an embodiment of the invention.

FIG. 6 shows a schematic view of a transparent cover in a VAD according to yet another embodiment of the present invention.

Fig. 7A-7D show schematic views of the housing of a VAD according to yet another embodiment of the invention.

Detailed Description

In order to more clearly understand the technical features, objects and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals indicate the same or structurally similar but functionally identical elements.

"exemplary" means "serving as an example, instance, or illustration" herein, and any illustration, embodiment, or steps described as "exemplary" herein should not be construed as a preferred or advantageous alternative.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, for simplicity and clarity of understanding, only one of the components having the same structure or function is schematically illustrated or labeled in some of the drawings.

In this document, "one" means not only "only one" but also a case of "more than one". In addition, in this document, "first", "second", and the like are used only for distinguishing one from another, and do not indicate the degree of importance, the order, and the like thereof.

Fig. 2 illustrates a wall mounted VAD200 according to one embodiment of the present invention. Fig. 3 illustratively shows an exploded view of the VAD200 shown in fig. 2. In the example of fig. 2 and 3, VAD200 includes a support plate 21, 6 lighting units 23, 6 reflector cups 25, a transparent cover 27, and a housing 29. Here, for convenience of description, 25 refers to a generic name of the reflector cup, or to any one of the reflector cups. 25x (x ═ 1, 3, 5) refers to a single specific reflector cup. The VAD200 is in use mounted on a wall in the manner shown in figure 1. In other words, the equivalent optical center of the VAD200 is centered on a top edge of the optical coverage space V. After being mounted on a wall, the transparent portion a, in which the plane of the supporting plate 21 of the VAD200 is parallel to the wall surface W and which can transmit light, faces downward.

As shown in fig. 2 and 3, the VAD200 has a generally disc-shaped outer shape. However, the profile of the VAD is not limited thereto, and it may be spherical, hemispherical, rectangular, ellipsoidal, or the like. Preferably, as shown in fig. 3, the transparent cover 27 is a complete disc-shaped cover which can be snapped onto the support plate 21, thereby forming a cavity. The light emitting unit 23 and the reflector cup 25 are accommodated in the cavity. The housing 29 may be snap-fitted to the transparent cover 27. The housing 29 also has a generally semicircular opening 292, and a transparent portion a is exposed through the opening 292, which just covers the light emitting unit 23 and the reflector cup 25.

In the example of fig. 2 and 3, 6 light emitting units 23 are provided on the support plate 21. The support plate 21 is preferably a driving circuit board capable of supporting the light emitting units 23 and transmitting driving signals to the respective light emitting units 23. In this example, the support plate 21 is a main circuit board, which is substantially disc-shaped. Alternatively, the support plate 21 may be a semi-ring shape just for placing the light emitting unit. Preferably, the support plate 21 may also be a driving plate of the light emitting unit instead of the main circuit board.

The 6 light emitting units 23 are arranged to be spaced apart from each other along a semicircular arc line C on the support plate 21. Preferably, the semi-circular arc C is near the edge of the support plate 21. Each light emitting unit 23 may include one, two or more LED chips. In the example of fig. 2 and 3, each light emitting unit 23 has two LED chips arranged side by side, and the adjacent light emitting units 23 are spaced substantially equally from each other. Alternatively, the number of the light emitting units 23 may also be three, four or five or more according to actual needs.

In fig. 2, 6 reflector cups 25 may be fixed to the support plate 21 and arranged together to form a semicircular ring. The opening of the reflecting cup is arranged on the periphery of the semicircular ring. Each reflector cup 25 may accommodate one light emitting unit 23. The inner surface of each reflector cup 25 is provided as a light reflecting surface capable of reflecting light emitted from the light emitting unit 23 toward an optical covered space V as shown in fig. 1, in which the VAD200 is disposed at a central position of a top edge of the optical covered space V. Alternatively, in fig. 2 and 3, the number of the reflective cups 25 may be 1, 2, 3 or more. One, two or more light emitting units 23 may be accommodated in each reflector cup. In the case of more than two reflector cups, two adjacent reflector cups may space apart the light emitting units in the respective reflector cups. Preferably, the 6 reflector cups 25 in fig. 3 are constructed as one integral piece 26, which extends substantially in the shape of a half-ring.

In the above embodiment, the VAD200 uses a plurality of discrete light-emitting units, and the light-emitting units are arranged at intervals along a semicircular arc line. With this distributed arrangement, the plurality of light emitting units can contribute to the light intensity output of the VAD together, which reduces the requirement for the light intensity output of each light emitting unit. If necessary, a plurality of light emitting units may also be arranged to provide a higher luminous flux for the purpose of covering a larger space. Meanwhile, the light emitting units are arranged near two end points of the semicircular arc line and matched with a reflecting structure such as a reflecting cup, so that the light intensity distribution close to the top surface of the light coverage space V can be improved, and the requirements of relevant standards can be met more easily. Thus, the example shown in fig. 2 can use a light emitting unit with lower power consumption and a light intensity distribution capable of satisfying the standard requirements. Furthermore, the light reflecting cup may be designed to reflect the light emitted from each light emitting unit toward the light covering space V. The design of the reflecting cup can also well meet the requirement of VAD on light intensity output in a specified direction, which is proposed by relevant standards, and effectively compensate the light intensity distribution.

Fig. 4A to 4C exemplarily show schematic diagrams of distributed arrangement of three kinds of light emitting units. For simplicity, components such as the reflector cup and the housing are omitted from FIGS. 4A-4C. In fig. 4A, VAD 400A includes 6 light-emitting units that are symmetric about centerline L-L'. The light emitting units are arranged along a semicircular arc line C at intervals. For example, the light emitting unit 432 is disposed near the midpoint L of the semicircular arc line. The light emitting unit 432 has one LED chip. The light emitting unit 436 is disposed near end points (B1, B2) of the semicircular arc line C. The light emitting unit 436 has three LED chips. The light emitting unit 434 located at the middle position has two LED chips. In other words, the more the reflective cup closer to the end point of the semicircular arc line C includes more LED chips in the example of fig. 4A. This design, in combination with the design of the reflector cup, is more advantageous for compensating the light intensity distribution in the area near the top surface of the optical covered space.

In fig. 4B, VAD 400B includes 6 light-emitting units that are symmetric about centerline L-L'. The light emitting units are arranged along a semicircular arc line C at intervals. Each of the light emitting units 435 includes a single LED chip, and an interval between every two adjacent light emitting units is gradually increased from the midpoint L to the end point.

In fig. 4C, VAD 400C includes 6 light-emitting units that are symmetric about centerline L-L'. The light emitting units are arranged along a semicircular arc line C at intervals. Each light emitting unit 439 comprises a single LED chip, and the light emitting units 438 are arranged on two sides of the semicircular arc line C in a staggered manner.

The 6-reflector cups 25 shown in fig. 2 and 3 are arranged in the shape of a semicircular ring, and the opening direction of each reflector cup is arranged on the outer periphery of the semicircular ring. The 6 reflector cups 25 are symmetrical about the centre line L-L'. Common features of the reflector cups of the present invention are described below with reference to one reflector cup 251 near the midpoint L in fig. 2 and 3. Fig. 5 shows a specific structure of a reflective cup 251. As shown in fig. 5, the reflective cup 251 is disposed to partially surround the light emitting unit 23, and its inner surface is a reflective surface. In fig. 5, the light emitting unit 23 is two LED chips arranged side by side. Preferably, the reflector cup inner surface is substantially concave. The inner surface of the reflector cup can be a continuous curved surface, and can also comprise more than two sub-curved surfaces which are adjacent to each other. Alternatively, a part of the surface in the light reflecting cup may be provided with a convex surface as long as it can reflect light toward the light covering space V.

As shown in fig. 5A, the reflective cup 251 has three main reflective portions 251_1, 251_3, and 251_5 adjacent to each other. The reflection portion 251_1 faces the light emitting unit 23, and is substantially concave, extending on the inner circumference of the semicircular ring. Fig. 5B shows a partial cross-sectional view of fig. 5A taken along line M-M'. The reflection portion 251_1 may reflect the light emitted from the light emitting unit 23 toward the light coverage space V. Preferably, as shown in fig. 5A, the reflection portion 251_1 may further specifically include, for example, three sub-reflection portions a, b, and c, which are abutted together. Each sub-reflecting portion extends in the direction of the inner circumference of the semicircular ring, and different sub-reflecting portions are superposed on each other. The curvatures and inclinations of the three sub-reflecting portions (sub-reflecting surfaces) are slightly different from each other so as to reflect incident light at different angles efficiently.

In the reflective cup 251 shown in fig. 5A, the reflective portion 251_3 is substantially opposite to the reflective portion 251_5, and the light emitting unit 23 is disposed between the reflective portions 251_3 and 251_ 5. As shown in fig. 5A, the reflection portions 251_3 and 251_5 are each inclined toward a direction away from the light emitting unit 23, thereby reflecting the light emitted from the light emitting unit 23 toward the light coverage space V thereof. The reflecting portions 251_3 and 251_5 are designed to increase the light intensity distribution area of the output light of the light emitting unit 23, thereby compensating for the light intensity distribution of the region outside the straight irradiation range of the light emitting unit 23, in other words, the two reflecting portions can reflect more energy emitted from the light emitting unit 23 toward the specified direction (light coverage space V) required by the standard.

Preferably, in order to ensure the light intensity distribution in the region near the top surface of the light covered space V, the light reflecting cup 251 is further provided with an auxiliary reflecting portion 251_7 at the edge located above the light emitting unit 23. The auxiliary reflection portion 251_7 is a concave surface extending in the circumferential direction. Preferably, one such concave surface is provided for each LED chip. In the example of fig. 5A, the reflective cup 251 has an auxiliary reflective portion 251_7 having two concave surfaces. The auxiliary reflecting portion 251_7 can enhance the light intensity distribution in the region near the top surface of the light covering space V.

In the example of fig. 5A, the reflective cup 251 further has a bottom surface 251_ 8. The bottom surface 251_8 is provided with an opening 251_9, and the light emitting unit 23 is adapted to pass through the opening 251_9 to expose the light emitting surface thereof. The bottom surface is preferably also a light reflecting surface. Alternatively, the reflector cup may not have a bottom surface and may be directly fixed to the support plate 21. On one hand, the bottom surface 251_8 may further reflect stray light occurring in the reflective cup 251 to effectively utilize the energy of the light emitting unit. On the other hand, the presence of the bottom surface 251_8 may make the overall structure of the 6 reflector cups arranged together more robust and durable.

Turning now to fig. 2 and 3. The 6 reflector cups 250 of fig. 2 and 3 are symmetrical about the centerline L-L', i.e., the reflector cups are symmetrical on either side of the centerline and have the same structure. The structure of reflector cup 253 and reflector cup 255 is substantially similar to the structure of reflector cup 251. Except that the two substantially opposite reflecting portions 253_3 and 253_5 of the reflector cup 253 are inclined in different directions. The reflection portion 253_3 near the end B1 is inclined toward a direction away from the light emitting unit 23, and the reflection portion 253_5 near the center line is inclined toward the light emitting unit. This design allows more light from the light emitting unit in the reflector cup 253 to be reflected toward the end portion B. More preferably, the reflection portion 253_3 includes three sub-reflection portions e, f, d stacked. The three sub-reflecting portions are each a conical surface, and the parameters such as curvature or inclination direction thereof are different from each other. Preferably, the sub-reflecting portion e occupies an area larger than the sum of the other two. The sub-reflecting portion e is inclined toward a direction away from the light emitting unit. The sub-reflecting portions f and d are inclined toward the light emitting element. Alternatively, the reflection portion 253_3 may also have one continuous reflection surface, or have 2, 4, or more sub-reflection portions. As shown in fig. 3, the reflection portion 253_5 may be a continuous reflection curved surface or a surface having a plurality of sub-reflection surfaces. The design of the reflective portion 253_3 of the reflective cup 253 is advantageous for reflecting the light emitted from the light emitting unit toward the end of the semicircular ring to enhance the light intensity distribution in the area near the top surface of the light covered space V.

Unlike the reflector cup 251 of fig. 5A, the two generally opposing reflective portions 255_3 and 255_5 of the reflector cup 255 of fig. 3 have different tilt directions. The reflection portion 255_3 near the end B is inclined toward the light emitting unit, and the reflection portion 255_5 near the center line is inclined away from the light emitting unit. This design may cause light emitted from the light emitting unit in the reflector cup 255 to be reflected more toward the end B. More preferably, the reflection part 255_3 includes three sub-reflection parts stacked. The three sub-reflecting portions are each a conical surface, and the parameters such as curvature or inclination direction thereof are different from each other. Preferably, the areas of the three sub-reflecting portions are substantially equivalent. Preferably, in the reflector cup 255, the reflecting portion 255_1 is a conical curved surface that tends to be flat. The reflection part 255_1 also preferably has two or more sub-reflection parts. The reflection portion 255_1 can better reflect the light toward the direction near the end B with the reflection surface tending to be flat, thereby enhancing the light intensity distribution near the area near the top surface in the light covered space.

Referring to fig. 3, the transparent cover 27 and the housing 29 function to protect the VAD internal components and enable light emitted by the VAD to be projected. Alternatively, the separate transparent cover 27 and the housing 29 in fig. 3 may be replaced with a housing having a transparent window, or with a completely transparent housing, or the transparent cover 27 may be omitted and the light emitting unit may be directly exposed to the outside. Preferably, the alarm shown in figure 3 is an audible and visual alarm. The transparent cover 27 has an acoustic channel portion 272. When the housing 29 is snap-fitted to the transparent cover 27, an acoustic cavity is formed at the acoustic channel portion 272. Therefore, the sound channel and the optical transparent cover can be simultaneously realized by adopting one integrated part 27, so that the whole product has higher integration level and simple processing procedure.

Fig. 6 shows an alternative of the transparent cover 27 by way of example. As shown in fig. 6, the transparent cover 67 is provided with at least one prism on the transparent part a thereof to scatter light emitted from the light emitting unit. In the example of fig. 6, the prisms are all disposed on the inner surface of the transparent cover 67. Two prisms 673 are exemplarily shown in fig. 6, each prism 673 extending circumferentially along the transparent cover. The number of prisms 673 may also be increased or decreased as desired. Preferably, the inner surface of the transparent cover 67 may also be provided with a prism 675 as shown in fig. 6. The prisms 675 extend in a direction perpendicular to the circumferential direction. The prism arranged on the transparent cover can effectively enlarge the diffusion angle of light emitted by a single light source, thereby improving the light intensity distribution of VAD.

Fig. 7A-7D illustratively show a VAD in accordance with yet another embodiment of the present invention. The VAD can realize the conversion from a sound-light alarm (beacon and sounder) to an audible alarm (sounder) by replacing the shell. In this embodiment, at least one of the reflector cup and the light emitting unit is detachable. Fig. 7A shows a perspective view of the housing 29 and transparent cover 27 of fig. 3 after they have been snapped together. As shown in fig. 7A, the housing 29 has a semicircular opening through which the transparent portion a of the transparent cover 27 is exposed. Fig. 7B shows a partial cross-sectional view taken along M-M' in fig. 7A. As shown in fig. 7B, the transparent cover 27 covers the light emitting unit 23 and the reflector cup 25. The housing 29 is snap-fitted to the transparent cover 27. The transparent cover 27 is provided with a protrusion 278 which just blocks the gap between the housing 29 and the transparent cover 27. Replacing the housing 29 in figures 7A and 7B with a complete disc housing 79 and removing the reflector cup 25 results in an acoustic alarm as shown in figure 7C. Fig. 7D shows a partial cross-sectional view of the acoustic alarm, in which the housing 79 completely covers the transparent cover 27, and in which the reflector cup 25 and the light-emitting unit 23 are not mounted. Therefore, two products of the audible and visual alarm and the audible and visual alarm can be obtained on the same basic structure without being changed too much. The design is convenient for production and processing, and therefore, the production cost is reduced.

It should be understood that although the present description has been described in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications such as combinations, divisions or repetitions of features, which do not depart from the technical spirit of the present invention, should be included in the scope of the present invention.

Claims

1. An alarm adapted for wall mounting, comprising:

a support plate (21);

at least three light-emitting units (23) arranged on the support plate (21) and spaced apart from each other along a substantially semicircular arc line (C);

-at least one reflector cup (25) fixable to said support plate (21) and each adapted to receive at least one of said lighting units (23), said reflector cups (25) extending or being arranged substantially in a semicircular ring shape, the inner surface of said reflector cup being a reflecting surface and being configured to reflect the light emitted by said lighting unit (23) towards a substantially cuboidal optical covering space (V), wherein the equivalent optical centre of said alarm is placed in the centre of a top edge of said optical covering space (V);

a replaceable housing (29, 79) at least partially covering a transparent cover (27), and at least one of said lighting unit and said reflector cup being removable; the replaceable housing is a first housing (29) having a semicircular opening adapted to expose the light emitting unit and the reflector cup, or the replaceable housing is a housing (79) completely covering the transparent cover.

2. The alarm of claim 1 wherein two adjacent reflector cups (25) space the light emitting units (23) within the two reflector cups from each other.

3. The alarm of claim 1, wherein the spacing between each two adjacent light units (23) is equal.

4. The alarm of claim 1, wherein the spacing between each two adjacent light units (23) is graduated.

5. The alarm of claim 1, wherein each light emitting unit (23) comprises two or more LED chips.

6. The alarm of claim 1, wherein each of the reflector cups (25) is arranged to partially surround at least one of the light emitting units (23) disposed therein, and the light exit openings of the reflector cups (25) are arranged on the outer periphery of the semicircular ring.

7. The alarm of claim 1, wherein the inner surface of the reflector cup (25) is concave, the reflector cup having opposing first and second reflective portions (251_3, 251_5) and the light emitting unit (23) being disposed between the first and second reflective portions (251_3, 251_5), wherein at least one of the first and second reflective portions is inclined away from the light emitting unit (23).

8. The alarm of claim 7 wherein the first and second reflective portions (251_3, 251_5) of the reflector cup (251) proximate the semi-circular mid-point (L) are each inclined away from the light emitting unit (23).

9. The alarm of claim 7 wherein, for a reflector cup (255) located near a semicircular end point (B1, B2), the first reflective portion (255_3) proximate the semicircular end point (B1, B2) is inclined towards the light emitting unit (23) and the second reflective portion (255_5) is inclined away from the light emitting unit (23).

10. An alarm unit according to claim 7 wherein the first or second reflective portion of at least one of the reflective cups comprises two or more sub-reflective portions (e, f, d) adjacent to each other, each sub-reflective portion being a reflective surface of a conical curved surface.

11. The alarm of claim 7, wherein each of said reflector cups (25) further comprises a third reflective portion (251_1) contiguous with said first and second reflective portions (251_3, 251_5) and facing said light emitting unit (23) housed in said reflector cup (25), said third reflective portion being concave.

12. The alarm of claim 11, wherein the third reflecting portion (251_1) comprises at least two sub-reflecting portions (a, b, c) adjacent to each other, each sub-reflecting portion being a reflecting surface of a conic type.

13. The alarm of claim 1, wherein each reflector cup (25) further comprises a first auxiliary reflective portion (251_7) disposed at an edge of the reflector cup above the light emitting unit, the first auxiliary reflective portion extending as a concave surface.

14. The alarm of claim 1, the transparent cover (27) being provided with at least one prism portion (673, 675) which is capable of directing light emitted by the light-emitting unit to be scattered towards the optical covered space (V).

15. An alarm unit according to claim 13, wherein the first auxiliary reflecting portion has a plurality of concave surfaces corresponding to the number and positions of the LED chips.

16. The alarm of claim 14, wherein the at least one prism portion comprises at least one prism portion (673) extending circumferentially of the transparent cover (67), or at least one prism portion (675) extending in a direction perpendicular to the circumferential direction of the transparent cover (67).