Signal generating segment with inner surface for homogeneous illumination

Abstract

A segment (S) for an optical signal generator is proposed, in which the inner surface (3) of the casing (2) is shaped in terms of its surface in such a way that it has a corrugated structure with a sequence of at least two notches (12) in each of the first and second illumination regions (AB1, AB1), wherein the sequence of valleys and peaks alternates along the line of curvature of the casing (2), while the valleys and / or peaks are arranged in a straight line parallel to the casing (2) and / or substantially, preferably completely perpendicular to the line of curvature along the inner surface (3) of the casing (2). For improved signaling, at least two of the notches (12) in one of the illumination regions (AB1, AB2) are geometrically differently designed.

Description

[0001] The invention relates to a segment for an optical signal generator according to the preamble of claim 1 and a signal generator according to the preamble of claim 19.

[0002] State-of-the-art signal generators are known, for example, in the form of signal columns that are attached to or on machines (such as production machines, machine tools, or the like). They signal the operating status of the machine using optical signals, e.g. a green segment for normal operating status, orange for a more critical condition that requires checking (e.g. when material needs to be refilled soon, a tool needs to be replaced soon, or the like), and red for an error. Such signal columns are typically made up of individual segments arranged one above the other or stacked. The signal columns are generally cylindrical. Inside this segment there is a light source, e.g. an LED or an array of LEDs.Because the light source is located at one location inside the diffuser and has only a small radiation area in relation to the area of ​​the viewing window, the basic problem is that when the light source is switched on, a bright spot of light can be seen where the light source is located or how far the radiation cone extends, while its surroundings are illuminated, but the brightness decreases increasingly with increasing distance. This is very pronounced with conventional segments from the state of the art; with some domes a few centimeters wide, in some cases only a localized light point is visible. For this reason, some segments have regular ribbed structures on the inner or outer surface of the dome or on the outside of the diffuser. However, this does not adequately correct the described effect.The problem is that the signal emitted by the signal generator is sometimes immediately noticeable or not so clearly recognizable.

[0003] The object of the invention is to provide a segment which enables particularly clear and distinct signaling.

[0004] The problem is solved, starting from a segment or a signal generator of the type mentioned at the beginning, by the characterising features of claim 1 or 19.

[0005] Advantageous embodiments and developments of the invention are possible by the measures mentioned in the dependent claims.

[0006] The segment according to the invention is a component for an optical signal generator. A segment that can emit optical signals can usually comprise a transparent dome as a viewing window or housing part, the surface of which is usually smooth. However, a diffuser can be inserted inside the dome. It is also conceivable for the dome and diffuser to be designed as a common or single component. The diffuser can, for example, have a cylindrical basic shape, the shell of which consists of material that is transparent in the visible spectral range. In principle, the diffuser does not have to be exactly cylindrical. A frustoconical basic shape is also conceivable, for example. Likewise, the dome can be cylindrical or frustoconical.

[0007] Typically, the transparent area of ​​the diffuser spans a 360° area. However, it is also conceivable that a smaller angular range is covered, for example, only 180°.

[0008] The segment further comprises a reference plane. Typically, a circuit board is arranged perpendicular to the base of the diffuser or segment, on which the electronics, or at least part of them, are arranged, including the light source and the optical signal element. Such a circuit board can thus run in the reference plane or, for example, slightly offset, parallel to it. The longitudinal axis of the segment, which is also perpendicular to the base and is arranged centrally or centrally thereon, can lie in the reference plane.

[0009] The optical signal element can radiate from the reference plane. Thus, the reference plane divides the space into two sides, with one of the signal elements located on one of the two sides. The signal elements can be mounted on both sides. The optical signal element often has its own radiation angle.

[0010] Within the scope of the invention, it was recognized that the side areas adjacent to the reference plane are generally the weakest illuminated because they lie outside the radiation angle and are only indirectly illuminated and thus significantly less well illuminated.

[0011] The invention therefore solves the problem of improving signaling by providing more homogeneous illumination. While ridges on the inner surface of the diffuser casing can provide indirect illumination of areas inside the diffuser, they only inadequately provide approximately homogeneous illumination inside the diffuser. According to the invention, this disadvantage is eliminated by making the structure on the inside of the diffuser casing inhomogeneous, specifically in such a way that the barely illuminated areas are more strongly illuminated indirectly.

[0012] The reference plane intersects the shell at two opposite points; thus, it encompasses a series of secant lines through the shell. If we consider the perpendiculars to the reference plane, each of which passes through the center of the secant, these separate two illumination areas.

[0013] In a segment according to the invention, the inner surface of the casing is shaped with respect to its surface in such a way that it has a corrugation structure with a sequence of at least two notches in each of the first and second illumination areas, wherein the sequence of valleys and peaks alternates along the curvature line of the casing, while the valleys and / or peaks are arranged in a straight line parallel to the casing and / or substantially, preferably completely perpendicular to the curvature line along the inner surface of the casing.

[0014] The line of curvature runs along a normal section, i.e. a section perpendicular to the longitudinal axis, which in turn is perpendicular to the base of the geometric body, i.e. the cylinder or truncated cone.

[0015] In addition, however, a segment according to the invention is characterized in that at least two of the notches in one of the illumination areas are geometrically different. This results in an anisotropic, angle-dependent reflection of the rays striking the inner surface, so that not only the area that lies centrally in the radiation angle range of the signal elements, for example, appears to be illuminated, but the edge area also receives sufficient light through reflections so that the diffuser appears uniformly illuminated on the inside. It is particularly advantageous if all of the notches are geometrically different so that a uniform transition is created with the adapted illumination between individual areas within the diffuser, i.e. from the outside, no brightness levels are visible with regard to the illumination.

[0016] Furthermore, an embodiment of the invention is characterized in that the inner surface of the casing is shaped with regard to its surface in such a way that, for at least part of the light from the signal element(s), a light beam consisting of parallel light rays emitted at a certain angle and extending in the first illumination region until reaching the casing is reflected at least partially into the first and at least partially into the second illumination region.

[0017] A light beam composed of several parallel light beams has a certain width. For example, light beams with a width of at least 10 µm, preferably at least 50 µm, and particularly preferably at least 100 µm are considered here. The measure according to the invention distributes the light so widely across the two illumination areas that the illumination can be significantly improved. This is because portions of the light cover both illumination areas.

[0018] The light beam, composed of parallel rays, has a certain width. The inner surface of the cladding, onto which the light beam strikes, is oriented in such a way that, as a rule, part of the light beam strikes the differently oriented surface profile at a different angle of incidence than another part, which strikes the profile slightly more closely. One part of the light beam is reflected into a different illumination area than the other part.

[0019] This is advantageously possible for both single-row and multi-row arrangements of signal elements. For example, one or more signal elements can be arranged in the center between the casing walls. Furthermore, signal elements can also be arranged on either side of the center on the reference plane between the casing surfaces, in particular symmetrically. The different rows are then arranged, for example, in different illumination areas.

[0020] The inner surface of the shell can also have edges, thus creating abrupt transitions between the differently oriented partial surfaces. With such a design, the transitions between differently oriented surfaces can occur more frequently and with greater density than with smooth transitions between the surfaces. Furthermore, manufacturing is generally simpler, meaning manufacturing costs can also be lower.

[0021] If a beam originating from the center or the longitudinal axis of the diffuser strikes a smooth, cylindrical surface, it would strike the surface perpendicularly and ideally be reflected back into itself. If the diffuser is truncated conically, the beam would only be deflected in or against the direction of inclination. At a larger angle of incidence, the beam is deflected more strongly laterally within the cross-sectional area of ​​the diffuser to improve illumination.

[0022] In a further development of the invention, the inner surface of the casing has a stepped structure. Each step consists of an edge, with a leg running on either side of it. The edges run essentially parallel to the casing or perpendicular to the curvature of the casing. If the casing is cylindrical, they run parallel to the longitudinal axis. In this way, a bundle of light rays, if it encloses the edge upon incidence, can be reflected via one leg in one spatial direction, for example into one of the two illumination areas, and via the other leg into another illumination area. In this way, the illumination can be improved.

[0023] As already shown, the edge can also be rounded. This allows the light rays to be deflected over a continuous angular range at the transition, which can also contribute to more homogeneous illumination.

[0024] In a particularly preferred design variant, the legs are designed differently. They can be of different lengths and / or inclined at different angles. The length of the legs generally influences the proportion of light reflected in a particular direction. The different inclinations influence the light distribution in the room.

[0025] If the limbs become monotonically longer toward one side of the essentially parallel edges, an increasingly larger proportion of light is deflected into the area in the direction in which the limbs also become longer. For example, assuming that the edge areas immediately adjacent to the reference plane are less illuminated due solely to the radiation of the signal elements, a larger proportion of the reflected light can reach this area to achieve more homogeneous illumination.

[0026] The surface orientations, i.e. their angular positions in relation to the respective incident rays, can also vary accordingly, so that in particular the angle of incidence increases or decreases in one direction along the lateral surface. In one embodiment, the steps can be designed such that the rays are deflected differently depending on whether they hit the lateral surface on one side or the other of the edge at a step. The orientations of the leg surfaces can be selected such that some of the rays which are approximately perpendicular or within a certain angular range around the perpendicular to the reference plane reach the other illumination region from which they do not originate, so that intensive rays can also reach the less illuminated edge regions. In this way, the homogeneity of the illumination is improved.In particular, such central rays, which run approximately perpendicular to the reference plane, should be deflected more strongly than rays which run through the peripheral areas anyway, so that a significantly brighter spot does not arise in the area of ​​the skin radiation angle.

[0027] The inner surfaces of the casing in the respective illumination areas can be mirror-symmetrical with respect to the perpendicular bisector. This configuration is particularly advantageous if the radiation area of ​​the signal elements is also mirror-symmetrical on both sides of the perpendicular bisector.

[0028] If a step is located exactly in the transition area between the two illumination areas, it can be axially symmetrical with equally long and equally oriented legs, with the perpendicular bisectors coinciding with their axis of symmetry.

[0029] Basically, the symmetry in these embodiments serves to ensure that the illumination is more even within the segment.

[0030] The illumination areas, in which the inner surface of the casing is specially designed by a corresponding profiling, such as the arrangement of steps for more uniform illumination of the interior volume of the segment, can cover different angular ranges depending on the embodiment, in particular depending on the radiation angle of the signal element(s), in particular at least 60°, preferably at least 80°, particularly preferably at least 90°, whereby the latter angular dimension means that the entire inner surface area is covered by a profiling. If the radiation angle of the signal element(s) is large enough, the angular range in which the inner surface has the profiling or steps can also be adjusted accordingly.

[0031] The optical medium or diffuser can advantageously be made of plastic. This allows for cost-effective and precise mass production using an injection molding process. The plastic can then be transparent in the visible wavelength range, allowing the light to be perceived as an optical signal. Furthermore, plastic is a relatively lightweight material, so the signaling device doesn't cause problems due to excessive weight.

[0032] The casing or its inner surface can be divided into sections. With a reference plane, for example, two sections or illumination areas can be arranged on each side of the reference plane, separated from each other by the perpendicular bisector. In this case, four sections or illumination areas are distributed across the diffuser, each covering a maximum of 90°. These illumination areas can in turn be mirror-symmetrical with respect to the reference surface. This design is particularly recommended when signal elements are arranged on both sides of the reference plane and emit the same or a similar light; this ensures that the optical appearance or illumination is similar or identical on both sides of the reference plane.

[0033] It should be noted that the segment can usually be viewed from essentially any direction, ie it is advantageous if the optical appearance of the segment (in the luminous and non-luminous state) is approximately angle-independent.

[0034] Monotonically increasing behavior occurs when a quantity, depending on its position or angular position, increases continuously in a given direction, or at least remains constant from one point to the next. In strictly monotonically increasing behavior, the value increases continuously from one point to the next and does not remain at a constant value in between. The opposite is true for (strictly) monotonically decreasing behavior.

[0035] In one embodiment of the invention, the height of the steps can also decrease monotonically, in particular strictly monotonically. This allows the steps to be formed with progressively more obtuse angles. Rays are thus deflected more strongly in one area than in the adjacent areas, which increasingly approximate a smooth contour of the inner surface.

[0036] On the outside of the casing, the profiling can be designed so that the radiation is as wide as possible, so that the segment radiates more evenly and appears uniformly bright to the outside. Since outward radiation in virtually all spatial directions is desired, the structure on the outside can also have surfaces that are aligned in all three spatial directions. In order to achieve almost uniform radiation, honeycomb-like structures, in particular with depressions and / or elevations, can be used. These structures can be attached to the outside of the diffuser, or for example, to the inside of the dome. In a further development of the invention, the segment is designed as a beacon and functions, for example, as a closing element. The diffuser comprises a roof sitting on the casing, which can, for example, be shaped like a vault.Here, too, such structures that diffusely distribute the emitted light can be embossed into the outer surface of the roof.

[0037] The reference plane may not only be a mathematical plane per se, but a carrier, in particular a circuit board, on which the signal element(s) are arranged can actually be arranged in the reference plane. This geometric arrangement also highlights the need to divide the diffuser into sections or illumination areas. The circuit board itself represents an essentially opaque area optically, i.e. an optical barrier that divides the segment into two halves. The circuit board can basically extend from one edge of the diffuser to the other, but it can also leave a gap open on one or both sides. If a gap is left open, the emitted light can also be guided from one side of the reference plane to the other side of the reference plane.If the circuit board reaches the diffuser casing, the shading caused by the circuit board is usually clearly visible from the outside, which is why it is advantageous to still have a gap.

[0038] As already explained, it can be assumed that the signal elements radiate away from the reference plane or circuit board within a specific beam angle range. To achieve more homogeneous illumination inside the diffuser, it is generally advantageous to deflect the rays that are more perpendicular to the reference plane more strongly than in peripheral areas, where less light shines directly anyway and where light rays must be directed more frequently.

[0039] The legs facing the board in the sequence of steps can therefore be shorter and shorter, the legs facing away from it can be longer and longer, whereby the height of the steps advantageously decreases more and more, so that the rays that reach the edge areas are also reflected back more and more strongly without being widely scattered in space.

[0040] Furthermore, a signal generator according to the invention with homogeneous illumination or radiation is characterized by the use of a segment according to the invention or an embodiment of the invention to distribute the emitted light more evenly. Such a signal generator can utilize the advantages of the invention provided by the proposed segment. Examples of implementation

[0041] Embodiments of the invention are illustrated in the drawings and are explained in more detail below, including further details and advantages. In detail: Fig. 1 and 2: each perspective view of a diffuser for a segment according to the invention, Fig. 3 and 4: the corresponding views of the diffuser from the Fig. 1 or 2 as a sectional view in Fig. 3 and from below in Fig. 4 , Fig. 5: the view from Fig. 3 , but with a drawn circuit board, signal elements arranged on it and a schematically shown beam path, Fig. 6: an enlarged view of the steps on the inner surface of the casing, and Fig. 7: a perspective view of a diffuser for a signal termination element (beacon).

[0042] The Figures 1 and 2show a diffuser 1 as part of a segment S of an optical signal generator. The diffuser 1 is designed as a one-piece plastic injection-molded part. The plastic forms the optical medium: It is translucent. In this case, the diffuser 1 is essentially cylindrical. It comprises a casing 2, whose envelope or basic shape is also cylindrical, with an inner surface 3 and an outer surface 4.

[0043] As in Figure 1As can be seen, the diffuser 1 ends on one side with a closure surface 5 that is interrupted in the middle. This closure surface 5 can be used for mounting, e.g., circuit boards, for through-plating from segment to segment, for mechanically connecting two adjacent segments, for optical isolation between two segments so that as little or no light as possible passes through from one segment to the next, or for similar purposes. The diffuser 1 ends with a base 6, which sits on top as a cylindrical body with a smaller diameter. Closure surface 5 is located on this base 6.

[0044] The casing 2 has an outer surface 4 with a honeycomb pattern formed by depressions. This generally radiates the light more evenly. The inner casing surface 3 is provided with a stepped profile. It is more clearly visible in Figure 2which shows an oblique view from below. The edges between the steps run parallel to the inner surface of the shell 3 and parallel to the longitudinal axis of the cylindrical segment 1.

[0045] In Figure 3 is a sectional view through the shell 2. The shell inner surface 3 has a stepped or sawtooth-like profile. Two axes R and M are shown. One axis marks the reference plane R, the other axis M runs as a perpendicular bisector M between the two intersection points where the axis R meets the shell inner surface 3. The quadrant in Figure 1 , which is located to the left of the perpendicular bisector M, is called the first illumination area AB1, while the right, adjacent quadrant on the other side of the perpendicular bisector M is called the second illumination area AB2.

[0046] Two beams enclose an angular range 7 from the reference plane R around the center point. In this area, a signal element is arranged in the reference plane R, which radiates into the angular range 7.

[0047] Where the perpendicular bisector M meets the inner surface 3, there is a step with two legs to the right and left of the perpendicular bisector M. This step is symmetrical to the axis of the perpendicular bisector M. For example, if one follows the inner surface 3 to the left in the first illumination area AB1, the right legs become longer and flatter from step to step, while the left legs become shorter and steeper. Likewise, the heights of the steps decrease further and further towards the reference plane R. In the area of ​​the reference plane R, the inner surface 3 appears to have an almost smooth edge.

[0048] It is also conceivable that the length of the legs changes from step to step only on one side (e.g. only to the right or only to the left of the respective edge) and remains the same on the other side.

[0049] In Figure 4 only a view of the diffuser 1 can be seen vertically from below, ie one can see the surrounding casing 2 and the view from below of the end surface 5.

[0050] Figure 5 basically shows the same view as Figure 3. In the reference plane R, a circuit board P with two signal elements (LEDs) 8a, 8b is shown, i.e. in two rows. The signal elements 8a, 8b emit light at a specific radiation angle. As an example, individual light rays 9a, 9b of the respective signal element 8a, 8b are selected here. Although the rays 9a run almost perpendicular to the reference plane R, they are reflected very far into the area 10 at the lateral edge of the circuit board P by the stepped structure of the inner surface 3. The area near the perpendicular bisector M is, as expected, very brightly illuminated due to the arrangement of the signal elements 8a, 8b and the radiation angle, since a high radiation density prevails there. If many rays are reflected from this area in the direction of the edge areas 10, 11, their illumination increases even more. The illumination in areas 10, 11 can therefore achieve similar brightnesses.This results in more homogeneous illumination inside the diffuser 1.

[0051] In Figure 6 An enlargement of the inner surface 3 of the optical medium or cladding 2 is shown. This shows a section of the stepped structure or profiling. The steps 12 have an edge 13 and two legs 14, 15. The right leg 14 is significantly longer than the left leg 15, which, however, has a steeper angle of incidence along the cladding 2 than leg 14. This allows light rays to be reflected very far to the right into area 10 or area 11. A wider bundle of light rays that impinges around edge 13 can thus reach two illumination areas AB1, AB2.

[0052] Figure 7shows a further development in the form of a so-called beacon. Only the diffuser 1 is shown. This is used as a closing element on a signal column and also radiates upwards. Therefore, not only the outer surface 4 of the casing 2 is provided with a honeycomb structure, but also the dome-shaped curved roof 20. It is conceivable in principle that the inner surface of the roof 20 is also provided with a groove pattern or a stepped structure. However, since the circuit boards with the lighting elements are usually perpendicular to the base surface and the roof 20 is only located in the lateral area of ​​the lighting element, the inner surface in the area of ​​the roof 20 is smooth. List of reference symbols:

[0053] 1Diffuser 2Sheath / optical medium 3Inner surface 4Outer surface 5End surface 6Base 7Beam angle 8aSignal element 8bSignal element 9aLight rays 9bLight rays 10Edge area 11Edge area 12Step 13Edge 14Leg 15Leg 20Roof AB1Illumination area AB2Illumination area MPerpendicular bisector PPirectangle RReference plane SSegment

Claims

1. Segment (S) for an optical signal generator • with a diffuser (1) for transmitting visible light and for homogenizing the light distribution in the volume delimited by the diffuser (1), wherein the diffuser (1) has a jacket (2) made of an optical medium that is transparent in the visible range and encloses a cylindrical or frustoconical volume, • with a reference plane (R) in which at least one optical signal element (8a, 8b) is arranged for emitting light towards the optical medium, wherein the reference plane (R) runs in a direction perpendicular to the base area of ​​the cylindrical or frustoconical volume, • wherein the bisectors (M) of the secants through the jacket (2) within the reference plane (R) divide the volume on at least one side of the reference plane (R) into a first and a second illumination region (AB1, AB2), • wherein the inner surface (3) of the jacket (2) is shaped with regard to its surface,that it has a corrugation structure with a sequence of at least two notches (12) in each of the first and second illumination areas (AB1, AB1), the sequence of valleys and peaks alternating along the curvature line of the casing (2), while the valleys and / or peaks are arranged in a straight line parallel to the casing (2) and / or substantially, preferably completely perpendicular to the curvature line along the inner surface (3) of the casing (2), • , characterized in that at least two of the notches (12) in one of the illumination areas (AB1, AB2) are geometrically differently designed, wherein in particular all of the notches (12) in one of the illumination areas (AB1, AB2) are geometrically differently designed.

2. Segment (S) according to claim 1, characterized in thatthe inner surface (3) of the casing (2) is shaped with regard to its surface in such a way that, for at least part of the light from the signal element(s) (8a, 8b), a light beam consisting of parallel light beams emitted at a specific angle and extending in the first illumination area (AB1) until reaching the casing (2), is reflected at least partially into the first and at least partially into the second illumination area (AB2).

3. Segment (S) according to claim 1 or 2, characterized in thata ray emanating from the center of one of the secants through the shell (2) within the reference plane (R), in particular a ray emanating from the center of the volume or a ray emanating from the center of a cross-sectional area of ​​the volume, has a greater angle of incidence at the point of impact on the shell (2) than if the area surrounding the point of impact on the shell inner surface (3) is tangentially aligned with respect to the line of curvature along the inner surface (3) of the shell (2).

4. Segment (S) according to one of the preceding claims, characterized in that the light beam(s) has / have a diameter of at least 10 µm, preferably at least 50 µm, particularly preferably at least 100 µm.

5. Segment (S) according to one of the preceding claims, characterized in thatthe inner surface (2) of the casing (3) has a stepped structure as a corrugation with a sequence of at least two steps (12) as notches, each step (12) being delimited by two legs (14, 15) which each abut one another at an edge (13), the edges (13) being arranged in a straight line parallel to the casing (2) and / or substantially, preferably completely perpendicular to the line of curvature along the inner surface (3) of the casing (2).

6. Segment (S) according to one of the preceding claims, characterized in that the inner surface (2) of the casing (3) has a rounded step structure with a sequence of at least two steps, each step being delimited by two legs which each meet at a rounded edge.

7. Segment (S) according to one of the preceding claims, characterized in thatthe steps (12) in the respective illumination area (AB1, AB2) are designed such that their legs (14, 15) become monotonously, in particular strictly monotonously, longer or shorter from step (12) to step (12) in the corresponding illumination area to one of the two sides of the edge (13).

8. Segment (S) according to one of the preceding claims, characterized in thatthe step structure is designed as follows: • The inner surface (2) of the casing (3) is designed in the first illumination area (AB1) with respect to the bisectors (M) of the secants through the casing (2) with respect to the step structure mirror-symmetrically to the inner surface of the casing in the second illumination area (AB2). • At least one of the steps (12) lies on the boundary between the first and second illumination areas (AB1, AB2) such that one of the legs (14, 15) lies in the first illumination area (AB1) and one of the legs (14, 15) lies in the second illumination area (AB2). • The inner surfaces (3) of the four illumination areas of the annular casing (2) are arranged mirror-symmetrically with respect to the reference surface (R).

9. Segment (S) according to one of the preceding claims, characterized in thatat least one of the illumination areas (AB1, AB2), in particular all illumination areas (AB1, AB2) cover a shape of the inner surface (3), in particular a step structure over an angular range of at least 60°, in particular at least 80°, preferably 90° in cross section and / or that the annular casing (2) is divided and / or arranged in a section in each of the four illumination areas (AB1, AB2), wherein in particular each illumination area (AB1, AB2) covers 90° in cross section.

10. Segment (S) according to one of the preceding claims, characterized in that the optical medium (2) is a plastic that is transparent in the visible wavelength range.

11. Segment (S) according to one of the preceding claims, characterized in thatthe height of the steps (12) of at least one of the illumination areas (AB1, AB2) becomes monotonically, in particular strictly monotonically, lower from step (12) to step (12), the height of the steps (12) being the radial distance of the respective edge (13) from the envelope of the contact points of the respectively adjacent steps (12).

12. Segment (S) according to one of the preceding claims, characterized in that the jacket (2) and / or the optical medium (2) is provided on its outer side (4) with a regular, in particular honeycomb-like structure, which is preferably formed from depressions and / or elevations.

13. Segment (S) according to one of the preceding claims, characterized in thata circuit board (P), on which the signal element or the signal elements (8a, 8b) are arranged, is arranged in the reference plane (R), wherein the circuit board (P): • separates the first and second illumination areas (AB1, AB2) from the remaining volume and / or • leaves a gap to the inner surface (3) of the casing (2) open at its edges on at least one, in particular on at least two opposite sides, and / or • wherein the inner surface (3) of the casing (2) is shaped such that parts of the light beams are directed through the gap by reflection.

14. Segment (S) according to one of the preceding claims, characterized in thatthe circuit board (P) is arranged in such a way that: • the shortening legs (14, 15) from step (12) to step (12) face the circuit board (P) and / or • the longer legs (14, 15) from step (12) to step (12) face away from the circuit board (P) and / or • the height of the steps (12) in at least one of the illumination areas (AB1, AB2) becomes monotonically, in particular strictly monotonically, lower from step (12) to step (12), the closer the corresponding step (12) is to the circuit board (P).

15. Signal generator with a segment (S) according to one of the preceding claims.

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