Technical Field

The present disclosure relate to an optical assembly, a lighting and/or signal indicating device, and a motor vehicle.

Background Art

As technology advances and society progresses, optical lighting or signal indicating devices is no longer restricted to providing lighting or signal indicator lamp functions. Thus, there are more and more demands regarding the personalization of optical lighting or signal indicating devices (e.g. vehicle lamps for motor vehicles); for example, one might wish that lighting or signal indicating light contains certain information or patterns to meet the requirements of personalized customization, while also wishing to present a specific illumination effect.

Summary of the invention

The present disclosure provide an optical assembly, a lighting and/or signal indicating device, and a motor vehicle, to solve at least one problem in the prior art.

According to one aspect of the present disclosure, an optical assembly is provided, comprising: a first light source and a second light source, respectively configured to emit light; a reflector, having a reflecting surface configured to reflect light from the first light source and the second light source; and a light guide member, configured to guide light rays from the second light source to the reflector, and having a light incident surface configured to receive light from the second light source and a light exit surface which outputs light from the second light source towards the reflector, the light exit surface being arranged to surface the reflector. The first light source and the light guide member are arranged such that light from the first light source passes through a through-hole formed in the light guide member and is incident on the reflecting surface, and is then reflected as a first light beam, and the second light source and the light guide member are arranged such that light from the second light source propagates through the light guide member and is incident on the reflecting surface, and is then reflected as a second light beam different from the first light beam.

According to an embodiment of the present disclosure, the light incident surface of the light guide member is at least part of a surface of the light guide member that is different from the light exit surface; light from the second light source enters the light guide member at the light incident surface, and propagates through the light guide member to the light exit surface.

According to a further embodiment of the present disclosure, the light incident surface of the light guide member is a lateral surface of the light guide member.

According to a further embodiment of the present disclosure, a light guide for guiding light from the second light source into the light guide member is provided between the second light source and the light guide member. For example, the light guide and the light guide member are integrally formed.

According to another further embodiment of the present disclosure, the light incident surface of the light guide member is a back surface of the light guide member opposite the light exit surface.

According to a further embodiment of the present disclosure, the first light source and the second light source are located on the same plane or different planes.

According to a further embodiment of the present disclosure, the light guide member further comprises a light adjustment structure disposed on the back surface.

According to an embodiment of the present disclosure, the light guide member is made of a transparent material. According to a further embodiment of the present disclosure, a fluorescent material is applied to the light incident surface of the light guide member.

According to an embodiment of the present disclosure, the light guide member further comprises a layer of semi-transparent, semi-reflective material disposed at the back surface.

According to an embodiment in another aspect of the present disclosure, a lighting and/or signal indicating device is provided, comprising: the optical assembly as described above.

According to an embodiment in another aspect of the present disclosure, a motor vehicle is provided, comprising: the lighting and/or signal indicating device as described above.

The optical assembly and the lighting and/or signal indicating device according to embodiments of the present disclosure can utilize an optical microstructure disposed on the back surface of the light guide member opposite the light exit surface to obtain the required intensity and form of emergent light, and can homogenize emergent light.

Brief description of the figures

Fig. 1 shows a 3D structural view of an optical assembly according to an embodiment of the present disclosure.

Fig. 2(a) shows a structural schematic diagram of an optical assembly and a lighting and/or signal indicating device comprising same according to an exemplary embodiment of the present disclosure, showing light propagation paths schematically.

Fig. 2(b) shows a structural schematic diagram of an optical assembly and a lighting and/or signal indicating device comprising same according to another exemplary embodiment of the present disclosure, showing light propagation paths schematically.

Fig. 2(c) shows a structural schematic diagram of an optical assembly and a lighting and/or signal indicating device comprising same according to another exemplary embodiment of the present disclosure, showing light propagation paths schematically.

Detailed description of embodiments

To more clearly expound the objective, technical solution and advantages of the present disclosure, embodiments of the present disclosure are described in detail below with reference to the drawings. It should be understood that the description of embodiments below is intended to explain and illustrate the general concept of the present disclosure, and should not be construed as limiting the present disclosure. In the specification and drawings, identical or similar reference labels denote identical or similar components or members. For clarity, the drawings are not necessarily drawn to scale, and certain well known components and structures might be omitted in the drawings.

Unless defined otherwise, the technical or scientific terms used in the present disclosure shall have the common meanings understood by those skilled in the art. The words “first”, “second” and similar words used in the present disclosure do not indicate any order, quantity or importance, being merely used to distinguish between different component parts. The word “a” or “one” does not rule out a plurality. Words such as “comprises” or “includes” mean that the element or object appearing before the word encompasses the elements or objects and their equivalents listed after the word, without excluding other elements or objects. Words such as “connected” or “linked” are not restricted to a physical or mechanical connection, and may include an electrical connection, whether direct or indirect. "Upper", "lower", "left", "right", “top” or “bottom”, etc. are only used to indicate a relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship might also change accordingly. When elements such as layers, films, regions or substrates are referred to as being located “on” or “under” another element, these elements may be “directly” located “on” or “under” another element, or there may be an intermediate element.

Fig. 1 shows a 3D structural view of an optical assembly 100 according to an embodiment of the present disclosure.

According to a general technical concept of embodiments of the present disclosure, e.g. as shown in the figure, an optical assembly 100 is provided, e.g. an optical assembly 100 mounted in a headlamp of a motor vehicle, intended to provide: a first light source 4, e.g. high beam HB/low beam LB, serving as a main light source; and a second light source 1, e.g. a second light source 1 serving as a signal indicating and/or ornamental light other than HB/LB. Thus, typically, in the optical assembly 100, the second light source 1 shares a lampshade and a reflector 2 for example with HB/LB serving as the first light source 4, but generally will not share a collimator and light distributor, etc. In a specific embodiment, as shown in the figure, as an example, the optical assembly 100 comprises: a first light source 4 and a second light source 1 , which are respectively configured to emit light; a reflector 2, having a reflecting surface 21 configured to outwardly reflect light from the first light source 4 and second light source 1 respectively; and a light guide member 3, located between the second light source 1 and the reflector 2, and the light guide member 3 having a light incident surface 30 and a light exit surface 31. The second light source 1 provides light coupled into the light incident surface 30, and the light incident surface 30 is configured to receive light from the second light source 1 ; and at the light exit surface 31, light from the second light source 1 emerges from the light guide member 3 towards the reflector 2. In a further embodiment, as an example, the light exit surface 31 is arranged to surface the reflector 2.

In an exemplary embodiment of the present disclosure, as an example, the first light source 4 and the light guide member 3 are arranged such that light from the first light source 4 passes through a through-hole 35 formed in the light guide member 3 and is incident on the reflecting surface 21, and is then reflected as a first light beam.

In an exemplary embodiment of the present disclosure, as an example, the second light source 3 and the light guide member 3 are arranged such that light from the second light source 1 propagates through the light guide member 3 and is incident on the reflecting surface 21 , and is then reflected as a second light beam different from the first light beam.

In an exemplary embodiment of the present disclosure, as an example, the light incident surface 30 of the light guide member 3 is at least part of a surface of the light guide member 3 that is different from the light exit surface 31 ; light from the second light source 1 enters the light guide member at the light incident surface 30, and propagates through the light guide member 3 to the light exit surface 31. Specifically, for example, a lateral surface 32 of the light guide member 3 (the lateral surface 32 being located in a lateral direction of the light exit surface 31) or a back surface 33 opposite the light exit surface 31 serves as the light incident surface 30.

Figs. 2(a) - 2(c) show structural schematic diagrams of the optical assembly 100 according to different embodiments of the present disclosure, showing different ways of positioning the first light source 4 and second light source 1 relative to the light guide member 3.

As an example, the first light source 4 and the second light source 1 are located on the same plane or different planes.

As an example, the first light source 4 and the second light source 1 comprise colour LEDs or monochromatic LEDs. In some more specific embodiments, for example, as shown in Figs. 2(a) and 2(b), the light incident surface 30 of the light guide member 3 is the lateral surface 32 of the light guide member 3 that is in the lateral direction relative to the normal to the light exit surface 31.

In other specific embodiments, for example, as shown in Fig. 2(b), a light guide 6 is additionally provided between the second light source 1 and the light guide member 3, the light guide 6 being configured to guide light from the second light source 1 into the light guide member 3 (into the lateral surface 32 thereof that serves as the light incident surface 30). As an example, the light guide 6 and the light guide member 3 are integrally formed, or are formed separately and then stuck together.

In other more specific embodiments, for example, as shown in Fig. 2(c), the light incident surface 30 of the light guide member 3 is the back surface 33 of the light guide member that is disposed opposite the light exit surface 31.

In an exemplary embodiment of the present disclosure, the second light source 1 for example comprises a white light or monochromatic light LED, but may also be another second light source 1 known in the art, e.g. an incandescent lamp, etc.

In an exemplary embodiment of the present disclosure, as an example, the reflector 2 has a shape that is sunken overall, and comprises multiple strip-like regions arranged side by side along the normal, the multiple strip-like regions being configured to form emergent light having a desired cut-off line.

In a further embodiment of the present disclosure, as an example, the reflecting surface 21 of the reflector 2 is formed to have an arcuate inwardly sunken shape, more specifically a paraboloid shape formed by at least part of a parabola moving along a straight or curved path.

In an embodiment of the present disclosure, for example, as shown in the figures, the light guide member 3 is for example an elongated light guide extending in a single direction. For example, the light guide member 3 comprises a transparent body extending in a single specific direction (becoming a main direction of the light guide member 3). It may extend along a straight line, a curved line or a combination of the two. A cross section thereof may adopt various shapes, e.g. circular, elliptical or polygonal.

As an example, the light guide member 3 may be made of a transparent material. For example, the light guide member is a one-piece member made of a single transparent glass, resin or plastic transparent material, e.g. poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA) or polycarbonate, inorganic or organic glass. The material may also be another light-permeable material, forming a light-permeable one-piece member.

In an embodiment of the present disclosure, the light guide member 3 for example further comprises a light adjustment structure 34 disposed on the back surface 33. As an example, the light adjustment structure 34 may be configured to reduce the light flux emerging from the light exit surface 31.

In an embodiment of the present disclosure, regarding the light adjustment structure 34 which is included in the light guide member 3, disposed on the back surface 33 and configured to reduce the light flux emerging from the light exit surface 31, the light adjustment structure 34 for example comprises an optical micro- structure formed by at least one of the following: multiple hemispherical protrusions or conical protrusions, multiple prismatic protrusions, multiple frosted granular protrusions, multiple bosses of trapezoidal cross section, or multiple sunken depressed mesh points. However, the present disclosure is not limited to this; as long as it can reduce the light flux at the region where it is located to obtain an expected light output flux and form, regardless of whether scattering or emergence at this position is utilized, no restrictions are placed on the form of any light-reducing optical micro- structure capable of serving as the light adjustment structure 34.

In a further embodiment, as an example, the distribution density of such an optical micro-structure intended to be used for light reduction of the light guide member 3 increases as the distance from the second light source 1 increases. In other words, the distribution density of the light-reducing optical micro- structure in a region of the light guide member 3 close to the second light source 1 is less than the distribution density of the light-reducing optical micro-structure in a region of the light guide member 3 remote from the second light source 1.

In a further embodiment, additionally or alternatively, as an example, the area of an orthographic projection of the light-reducing optical micro-structure of the light guide member 3 onto the back surface 33 of the light guide member increases as the distance between the light-reducing optical micro-structure and the second light source 1 increases.

Because the light intensity is greater in a region close to the second light source 1, the use of such a method of gradually increasing the distribution density and/or area of the light-reducing optical micro-structure as the distance from the second light source 1 increases is conducive to uniform distribution of intensity of light emerging from the light guide member, so can homogenize emergent light to provide uniform light output.

In an alternative embodiment, for example, the optical micro- structure of the light guide member 3 may also be arranged in an array.

Through the above arrangement, in particular the light adjustment structure 34 located on the back surface 33 of the light guide member 3, for example it serves as a light withdrawal structure so that light propagating in the light guide member 3, upon reaching this position, is withdrawn from the back surface 33 of the light guide member 3 in a direction away from the expected exit direction of light, or serves as a light diffusion structure to change the ideal transmission direction of light (in the case where no such light adjustment structure 34 is provided) in a divergent manner, thereby achieving the effect of reducing light flux, and is even further configured to shape light, e.g. realize light having an expected wavefront and light flux, to obtain a good irradiation appearance of emergent light. In a further embodiment, for example, a fluorescent material is applied to a surface serving as the light incident surface 30 of the light guide member 3, to receive light from the second light source 1. The fluorescent material is for example applied to the light incident surface 30 as particles of a fluorescent substance in an initial state, and is cured to a solid state in a subsequent curing process step. In an embodiment of the present disclosure, the fluorescent material is used to convert light emitted by the second light source 1 to another colour of light. As a specific example, the second light source 1 for example comprises and distributes at least two LED chips configured to emit light of different single colours, and the fluorescent material converts blue light emitted by one LED chip serving as the second light source 1 to yellow light which subsequently mixes with blue light emitted by the other LED chip to produce white light; or the incidence of blue light emitted by a blue light LED onto a yellow fluorescent material is utilized to produce white light. Fluorescent materials include but are not limited to materials such as silicate, YAG (yttrium aluminium garnet), KSF (fluoride), and also include QD (quantum dot) and other photoluminescent materials.

In an alternative embodiment, for example, the light guide member 3 is a one-piece member made of a fluorescent material, which is typically for example a transparent fluorescent ceramic material.

In a specific embodiment, as an example, the light guide member 3 further comprises multiple light withdrawal structures distributed on the light exit surface 31, and light propagating in the light guide member 3 emerges at the multiple light withdrawal structures towards the reflector 2.

In a further embodiment, the multiple light withdrawal structures are provided on the light exit surface 31 of the light guide member 3, the multiple light withdrawal structures being arranged facing the reflector 2, such that light totally reflected in the light guide member 3 is for example withdrawn from the light guide member 3 through the multiple light withdrawal structures and guided towards the reflector 2 for subsequent reflection and emergence. Examples of light withdrawal structures include multiple discretely arranged protrusions integrally formed on the light exit surface 31, for example in the shape of hemispherical protrusions or conical protrusions, which make it easier to guide light out of the light guide member 3. Of course, the shape of the multiple light withdrawal structures is not limited to this, and other shapes may be chosen, e.g. bosses of trapezoidal cross section; or the light withdrawal structures may also be depressed mesh points sunk from the light exit surface 31 of the light guide member 3. As long as they can guide light out of the light guide member 3, no limitations are placed on the shape of the light withdrawal structures.

Moreover, between adjacent light withdrawal structures, loss caused by undesired light emergence is avoided typically through total reflection between the material of the light guide member 3 and the external environment such as air. In addition, an additional light-blocking optical micro-structure may also be provided between adjacent light withdrawal structures of the light exit surface 31, for preventing undesired emergence of light from between adjacent light withdrawal structures.

According to a particular embodiment, as an example, the light-blocking optical micro-structure comprises multiple sawtooth protrusions which are disposed on the light exit surface 31 of the light guide member 3 and more specifically distributed between adjacent light withdrawal structures, each sawtooth protrusion comprising an inclined surface, for reflecting light rays directed towards the inclined surface from the interior of the light guide member 3 back into the light guide member 3, preventing light loss at this position and thereby improving the light effect at this position. Those skilled in the art will understand that the specific form of the optical micro- structure is not limited to sawtooth protrusions; any structure capable of preventing the emergence of light from between adjacent light withdrawal structures of the light exit surface 31 of the light guide member 3 can serve as the light-blocking optical micro-structure of the present disclosure.

Optionally, according to an exemplary embodiment, a reflective coating may also be provided on a surface of the light-blocking optical micro-structure that is located outside the light guide member 3; the reflective coating is for example made of a white reflective or silver reflective material, to further prevent the emergence of light from the multiple light-blocking optical micro-structures, and improve the light effect.

In a specific embodiment, depending on the positioning of the second light source 1 relative to the light guide member 3, different surfaces of the light guide member 3 serve as the light incident surface 30.

In one example, Fig. 2(a) shows a structural schematic diagram of the optical assembly 100 according to an exemplary embodiment of the present disclosure, showing light propagation paths schematically. In an exemplary embodiment of the present disclosure, as shown in the figure, the second light source 1 is arranged to adjacently abut the lateral surface 32 of the light guide member 3, and the lateral surface 32 of the light guide member 3 serves as the light incident surface 30. The through-hole 35, which is for example centrally disposed, is formed in the light guide member 3, to place a heat sink and the other, different, first light source 4.

In this case, the second light source 1 is a side-entry second light source 1 located at a side part of the light guide member 3.

According to an embodiment of the present disclosure, for example, light emitted from such a side-entry second light source 1 enters the light guide member 3 directly from the lateral surface 32 of the light guide member 3 adjacent to the light source, and then for example propagates away from the second light source 1 substantially in the extension direction of the light guide member 3 (i.e. the abovementioned lateral direction) by total reflection at the interface of the light guide member 3 with the external environment (e.g. air). In another embodiment, as shown in Fig. 2(b), this shows a structural schematic diagram of the optical assembly 100 according to another exemplary embodiment of the present disclosure, showing light propagation paths schematically. A light guide 6 located between the second light source 1 and the light guide member 3 is additionally provided; the light guide 6 for example lies tightly against a lateral surface 31 serving as the light incident surface 30 of the light guide member as shown in the figure, and is configured to guide light from the second light source 1 into the light guide member 3. As an example, as shown in Fig. 2(b), the second light source 1 is arranged opposite and spaced apart from the light guide 6 disposed at a side of the light guide member 3; the through-hole 35, which is for example centrally disposed, is formed in the light guide member 3, to place a heat sink and the other, different, first light source 4. In this case (the second light source 1 being a straight-down second light source 1 positioned at a side), light from the second light source 1 enters the light guide 6 directly; and as shown in the figure, the light guide 6 for example has an obliquely disposed side edge (e.g. at the critical angle for total reflection relative to the light exit surface 31 and the back surface 33), incident light is incident with total reflection at the side edge and propagates through the light guide 6, then enters the light guide 3 at the interface where the light guide 6 adjoins the lateral surface 32 serving as the light incident surface 30 of the light guide member 3, thereby obtaining an incident light effect substantially equivalent to that of the side-entry second light source 1 in Fig. 2(a). With such an arrangement combining the light guide 6 additionally disposed in the lateral direction and the straight-down second light source 1 opposite thereto, the total reflection critical angle configuration at the oblique edge of the light guide results in total reflection incidence at the lateral surface 32 of the light guide member 3, thus realizing incident light that is substantially equivalent to that of the side-entry second light source 1, but also realizing a more compact structure. In another alternative example, Fig. 2(c) separately shows a structural schematic diagram of the optical assembly 100 according to another exemplary embodiment of the present disclosure, showing light propagation paths schematically. As shown in the figure, the second light source 1 is arranged to be spaced apart from the back surface 33 of the light guide member 3, and the back surface 33 serves as the light incident surface 30.

As an example, as shown in Fig. 2(c), the second light source 1 is arranged to be located behind the back surface 33 of the light guide member 3 ; the through- hole 35, which is for example centrally disposed, is formed in the light guide member 3, to place a heat sink and even another, different, second light source 1. In this case (the second light source 1 being a straight-down second light source 1 positioned at a rear side), light from the second light source 1 is projected directly onto parts at two sides of the back surface 33 of the light guide member 3 (i.e. the parts at the two sides (the parts respectively located at two sides of the central through-hole 35) of the back surface 33 serve as the light incident surface 30).

In the case of the arrangement of the side-entry second light source 1 as shown in Fig. 2(a) and described above, and in the case of the substantially equivalent arrangement of the straight-down second light source 1 opposite the oblique side edge of the light guide 6 as shown in Fig. 2(b) (which substantially transforms to the equivalent side-entry second light source 1 by utilizing total reflection incidence at the lateral surface 32), the abovementioned light-reducing optical micro-structure may be provided on the back surface 33 of the light guide member 3, for reducing light flux and thereby achieving the expected intensity and form of emergent light.

In the case of the arrangement of the straight-down second light source 1 positioned at the rear side as shown in Fig. 2(c) and described above, a layer of semi-transparent, semi-reflective material may be additionally or alternatively provided on the back surface 33 of the light guide member 3, for reducing incident light that is directly incident on the back surface 33 from behind, to facilitate the reduction of light flux to achieve the expected intensity and form of emergent light.

In the case of Fig. 2(c), if the combined action of the semi-transparent, semi- reflective material layer and the light-reducing optical micro-structure on the back surface 33 of the light guide member 3 is utilized, then for example, the optical micro- structure with the uneven form is used to diffuse incident light in different directions, while the semi-transparent, semi-reflective material layer is used to directly weaken directly incident or nearly directly incident light, thereby achieving a combined light reduction effect.

According to the general concept of embodiments of the present disclosure, in another aspect of the present disclosure, for example, as shown in Figs. 2(a) - 2(c), a lighting and/or signal indicating device is also provided, comprising: an optical assembly 100 as described above, wherein the second light source 1 serves as an auxiliary light source that is different from the first light source 4 (serving as the main light source) and configured to emit signal indicating light or ornamental light. The first light source 4 serving as the main light source and the second light source 1 serving as the auxiliary light source share the reflector, which reflects the main illuminating light and the signal indicating light or ornamental light towards the outside of the device.

In an exemplary embodiment of the present disclosure, for example, the main light source 4 is an HB/LB light source module.

In an exemplary embodiment of the present disclosure, for example, the through-hole 35, which is for example centrally disposed, is formed in the light guide member 3, to place a heat sink and implement the main light source 4 and a PCB substrate thereof.

In an exemplary embodiment of the present disclosure, for example, the lighting and/or signal indicating device further comprises a light distribution structure, located at or near a focus of the reflector 2, and configured to adjust light from the main light source 4 so that the light emitted by the main light source 4 forms substantially parallel emergent HB/LB light after reflection by the reflecting surface 21 of the reflector 2.

In the case of the arrangement of the side-entry second light source 1 as shown in Fig. 2(a) and described above, a PCB of the HB/LB light source module serving as the main light source 4 is for example disposed on a flat base part of a heat sink 41 at or near the central through-hole 35 of the light guide member 3 (multiple cooling fins are provided on another side surface of the heat sink, e.g. on a back surface, opposite a side surface of the flat base part on which the HB/LB light source module and PCB thereof are mounted), while a PCB of the second light source 1 serving as the auxiliary light source 1 emitting the signal indicating light or ornamental light is for example disposed on the lateral surface 32 at a side part of the light guide member 3. The PCB of the main light source 4 and the PCB of the second light source 1 are disposed independently of each other.

In the case of the arrangement of the straight-down second light source 1 opposite the oblique side edge of the light guide 6 as shown in Fig. 2(b) which is substantially equivalent to Fig. 2(a) and described above (which substantially transforms to the equivalent side-entry second light source 1 by utilizing total reflection incidence at the side edge of the light guide 6), the PCB of the HB/LB light source module serving as the main light source 4 is for example disposed on a base part of the heat sink 41 at or near the central through-hole 35 of the light guide member 3, while the PCB of the second light source 1 serving as the auxiliary light source 1 emitting the signal indicating light or ornamental light is for example also disposed on the base part of the heat sink 41 (more specifically at an edge of the base part of the heat sink 41). Thus, the PCB of the main light source 4 and the PCB of the second light source 1 may be shared by each other. Of course, the PCBs of both light sources may also be disposed independently of each other.

In the case of the arrangement of the straight-down second light source 1 positioned at the rear side as shown in Fig. 2(a) and described above, the PCB of the main light source 4 and the PCB of the second light source 1 are for example disposed separately, and are thus disposed independently of each other.

Such a lighting and/or signal indicating device, as a result of comprising the optical assembly 100, has all of the advantages and technical effects of the lightreducing optical micro-structure of the optical assembly 100, in particular located on the back surface 33 of the light guide member thereof, and these are not repeated here.

According to another aspect of embodiments of the present disclosure, a motor vehicle is also provided, comprising: the lighting and/or signal indicating device as described above. The motor vehicle for example further comprises a vehicle body to which the lighting and/or signal indicating device is fitted. Since the motor vehicle comprises the lighting and/or signal indicating device, in particular the optical assembly 100, it has all of the advantages and technical effects of the light-reducing optical micro-structure of the optical assembly 100, in particular located on the back surface 33 of the light guide member thereof, and these are not repeated here.

Although the present disclosure has been explained in conjunction with the drawings, the embodiments disclosed in the drawings are intended to provide an exemplary illustration of preferred embodiments of the present disclosure, and must not be interpreted as a limitation of the present disclosure.

Although some embodiments of the general concept of the present disclosure have been shown and explained, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept. The scope of the present disclosure is defined by the claims and their equivalents.