Abstract: The illuminating device includes a light source and a light guide plate. The light guide plate has a first side surface receiving light emitted from the light source, a second side surface facing the first side surface, a third side surface, a fourth side surface, an emitting surface and an opposing surface. The third and fourth side surfaces are located between the first and second side surfaces so as to face each other, and the emitting surface and the opposing surface face each other. The light guide plate is formed from a first light guide layer and a second light guide layer. The first light guide layer has a plurality of reflecting films therein for reflecting light entering the light guide plate through the first side surface toward the emitting surface. The second light guide layer has no reflecting film.

Abstract: A unique, solid flat panel lighting emitting luminaire has been created that utilizes a light source remote from the luminaire coupled with a hollow light pipe. The light panel luminaire is fed light flux via a hollow light pipe system into one or two edges of the flat panel. The light panel has imbedded irregular tapered tetrahedron light guides that emit light in a uniform controlled fashion over the length of the emitting surface. The subject lighting luminaire provides light emitted from an adjacent High Intensity Discharge (HID) light source. The luminaire is specifically designed to provide light over a large surface for backlit billboard applications without the limitations of traditional fluorescent light source light boxes. The luminaire does not require any maintenance to its interior as the light source is remote from the emitting surface.

Abstract: A fiberoptic lighting system has a light source with a bulbous section and a plurality of plastic light pipes having substantially circular cross sections. A collector has an inlet for receiving light from the light source and an outlet. The collector performs an area-to-angle conversion on light it collects from the light source. A plurality of rods receives light from the collector and passes such light to the plastic light pipes, while thermally isolating the plastic light pipes from the light source. A perimeter of an outlet of the collector has a plurality of shaped portions, each associated with, and each substantially shaped the same as, a substantial portion of an associated perimeter of a respective one of the plurality of rods. The foregoing system delivers a higher percentage of light from a light source into multiple light pipes than in a prior art system.

Abstract: A point light source is converted into a plane light source having a satisfactory uniformity. The point light source is converted into a line light source by means of a linear light guiding plate, and further into the plane light source by means of a plane-like light guiding plate. Light from the point light source is reflected at a lamp reflector to be incident on at least two side surfaces of the plane-like light guiding plate.

Abstract: A planar-light apparatus with a non-straight direction light module is provided. The planar-light apparatus mainly comprises a light-guiding plate and a light module. The light-guiding plate comprises a light-incident surface and a light-output surface perpendicular to the light-incident surface, and a scattering surface opposite to the light-output surface. Further, the light module connected to the light-guiding plate is used for emitting a light onto the light-incident surface, and the light module is opposite to the light-incident surface of the light-guiding plate with a certain angle of incidence. The light is incident from the light-incident surface onto the light-guiding plate with a certain angle of incidence. Therefore, the first time the light is reflected, the inclination angle of the normal of the scattering surface is reduced, so that the number of the light reflections in the light-guiding plate is also reduced.

Abstract: A linear light source device is provided having a main body that includes at least a light-guided bar and a light source assembly. The light-guided bar is a polygonal column with one striped surface forming, a reflective plane. The plane the opposite to reflective plane is a light-exiting plane having a convex profile, with the remaining planes being reflective planes. At least one of the ends of the polygonal column is an incident plane for a light beam to enter. The light beam is uniformly transmitted through the convex-shaped light-exiting plane.

Abstract: According to this invention, a side-emitting illumination device for uniformly distributing light is composed of an LED light source, a light-transmitting rod which permits total internal reflection, and outcoupling material affixed to an outer surface of the rod. Light enters the rod at one end and travels along the rod by total internal reflection. Light that hits the outcoupling material is angularly distributed based on the width of the outcoupling material.

Abstract: A housing for computer or the like includes a front wall, a refractive planer member attached to the housing and having a rib or a swelling engaged into the housing, and a light device disposed in the housing for generating light through the planer member and toward the rib and the swelling, and for allowing the light to be seen through the rib or the swelling. The rib has two curved ends for flushing with the curved sides of the housing. The planer member includes a curved recess formed in a bulge and facing toward the light device for receiving the light generated by the light device.

Abstract: An apparatus for positioning and adjusting a light pipe includes a bracket that is formed by folding a metallic plate. When the metallic plate is folded to form the bracket, a first end and a second end of the metallic plate perpendicularly press against each other to form a close space for accommodating the light pipe. The apparatus for positioning and adjusting a light pipe further includes a clip device for positioning the bracket. A first adjustment screw has a front end pressing against the side surface of the bracket. A second adjustment screw has a front end pressing against the bottom surface of the bracket. The horizontal position of the light pipe is modified by adjusting the first adjustment screw. The vertical position of the light pipe is modified by adjusting the second adjustment screw.

Abstract: A positioning structure of a back light module has an optical film and a frame, wherein at least one flange is respectively disposed at two corresponding edges of the optical film and the flange has a neck portion. The frame is used to position the optical film and includes base, a constraining block and a bridge, wherein the base is used to contain the flange of the optical film, and the constraining block protrudes from the surface of the base and corresponds to the neck portion of the flange so as to restrict displacement of the flange parallel to the surface of the base, and the bridge is mounted on the top of the base to constrain the displacement of the flange perpendicular to the direction of the surface of the base. In addition, appropriate gaps are retained both between the constraining block and the neck portion of the flange, and between the bridge and the flange such that the optical film can freely extend when it is heated to deform.

Abstract: Transflective display device has an optical waveguide commonly known as a light guide. The guide includes areas having a chiral nematic structure which splits light coming in from aside into two light beams having a mutually opposite circular polarization. Polarization splitting is achieved at the interface of the areas having the chiral nematic structure.

Abstract: A rotary electric component capable of reliably preventing light leakage due to the looseness of a faceplate over a long period of time is provided. In the rotary electric component, an annular thin faceplate 3 disposed around a rotary knob 2 is provided with a display portion 3a illuminated through a light guiding member 5 (an outer ring portion 5b) from the rear surface side thereof, an inner circumferential portion and an outer circumferential portion of the rear surface of the faceplate 3 are bonded and fixed to a holder 4, and the rotary knob 2 and the display portion 3a is assembled in an cutout 11 of a front panel 10 in an exposed state.

Abstract: A vehicle lamp that includes a light-emitting diode group formed by light-emitting diodes, which are disposed in a row with the irradiation direction directed toward the front of the lamp, and a light guiding plate, which is a transparent plate and is provided in front of the light-emitting diode group so as to be in the front-back direction of the lamp; and a plurality of light guiding plate units are provided inside a lamp chamber so that the light guiding plate units are spacedly disposed one on the other, each of the light guiding plate units causing the light from the light-emitting diodes to enter the light guiding plate from the rear end surface of the light guiding plate and further causing the light to exit from the front end surface of the light guiding plate toward the front of the lamp.

Abstract: In a backlighted knob, as for automotive use, an indicator and a light pipe are molded simultaneously so as to be intimately bonded to each other, in a translucent structure. A polymeric body, which comprises a front wall and a central hub, is molded around the translucent structure as to cause the front wall and the translucent structure to be intimately bonded to each other. An outer cover is molded so as to cover an outer face of the front wall, except that the indicator is exposed through an aperture in the front wall and through an aperture in the outer cover. The indicator and the light pipe are translucent. The polymeric body and the outer cover are opaque. The indicator exhibits a light color, such as white, in ambient light. The light pipe is tinted so as to cause the indicator to exhibit a color contrasting with the light color when the light pipe is backlighted.

Abstract: An LED is mounted on a flexible wiring board, and this flexible wiring board is adhered by a both-surface adhesive tape to a back of a light guiding plate to which a light reflecting film is adhered by an adhesive layer. The LED is kept at a desired set position by retaining the LED by a retaining section formed integrally with the light guiding plate in a state where a light emitting surface of the LED airtightly contacts a light entrance end surface of the light guiding plate, and by adhering a rear surface of the LED to an inner surface of the retaining section by an adhesive agent.

Abstract: A backlight module, suitable for supplying a plane light source. The backlight module has a light guide plate, a reflection mask and a light compensator. The light source is disposed next to a side surface of the light guide plate, such that the light generated thereby is incident on the side surface of the light guide plate, transmitted through the bottom surface, and projecting from the top surface of the light guide plate. The reflection mask is disposed next to the sidewall of the light guide plate to cover the light source. The light compensator is disposed in the reflection mask. By disposing the light compensator with multiple reflection planes in the reflection mask or forming multiple reflection surfaces of the reflection mask, the brightness at the two comers of the light guide plate near the two sides of the light source can be compensated.

Abstract: A knob section includes an elastic pawl protruding downward and contacting an outer surface of a light guide unit at an inner surface of the pawl. A holder includes a holding section contacting an outer surface of the elastic pawl. An illumination knob is provided by latching a recess of the elastic pawl to a protrusion of the holding section. The elastic pawl is sandwiched between an outer surface of the light guide unit and the holding section, thus allowing constituent components of the illumination knob to be held securely.

Abstract: A display apparatus adapted to be mounted on an audio/video player or the like comprises a housing having a window. A backlight unit having a plate mounted in said housing and made of transparent materials which has a front surface and a back surface, and a plurality of reflecting pieces disposed on the back surface of said plate and being gradually enlarged by distance. A light set has a LED arranged beside the plate of the backlight unit nearby said the reflecting pieces of smaller sizes to emit light to the backlight unit and reflected by the reflecting pieces to the front surface of the plate. A screen is mounted in the housing and disposed in front of the front surface of the backlight unit corresponding in location to the window of the housing, the screen is capable of passing the light reflected by said backlight unit.

Abstract: The light guide plate 32 has a light receiving portion 36 on one side thereof to receive light emitted by the LED 24 and a flexible light guide body 35 for transforming the light received by the light receiving portion 36 into planar light. The light guide body 35 is arranged along the liquid crystal panel 23 and has a plurality of light scattering portions 30 arranged on an outer surface thereof in a propagation direction of light emitted by the LED 24. Since the light guide plate 32 comprises a flexible member and thus can be arranged in a curved shape conforming to the liquid crystal panel 23 having a curved surface portion, the curved surface portion of the liquid crystal panel 23 can be illuminated uniformly. Further, the provision of the light scattering portions 30 can enhance a light reception efficiency and light emission efficiency even if the light guide plate 32 is thin.

Abstract: A surface light source (3, 4, 5) includes a light guide plate (32, 42, 52), which defines an incident surface (321, 421, 521), an emitting surface and a bottom surface (323, 423, 523) opposite to the emitting surface; and a light source (31, 41, 51) adjacent to the incident surface of the light guide plate for radiating light beams into the light guide plate through the incident surface. A multiplicity of generally rectangular dots (328, 428, 528) and generally circular dots (329, 429, 529) is formed on the bottom surface of the light guide plate. The rectangular and circular dots reflect and scatter the light beams in directions toward the emitting surface. The rectangular dots are distributed on the bottom surface corresponding to lower luminance areas of the light guide plate, so that the luminance over the whole emitting surface of the light guide plate is uniform.

Abstract: A reflector has a curved part covering the light source and a pair of end parts extending at the two sides of the curved part. The inside surface of each end part has a plurality of substantially parallel projections or depressions. The light-guiding plate has an incident surface and an emission surface substantially perpendicular to the incident surface, the incident surface having a plurality of projections or depressions extending substantially parallel to the emission surface. Also, the reflection surface of the light-guiding plate has projections.

Abstract: An illuminating-light controller includes a light modulator for projecting light on a corresponding area by tilting a reflecting surface. A first light source emits a first light that is projected on the corresponding area by illuminating the first light to the reflecting surface of the spatial light modulator being tilted at a first angle. A second light source for emits a second light that is projected on the corresponding area by illuminating the second light to the reflecting surface of the light modulator being tilted at a second angle. Still further, included is a control section for controlling the first light emitted from the first light source and the second light emitted from said second light source.

Abstract: A front light module includes a light guide plate having opposite ends and a front surface and an opposite back surface connected to each other by the ends. The front surface forms sets of raised ridges, each raised ridge having opposite inclined faces. The front surface also forms a recessed trough between adjacent sets of ridges. Each trough has opposite inclined faces. A light source is mounted to each end of the light guide plate for projecting a light into the light guide plate. A reflector is arranged adjacent to and spaced from the back surface of the light guide plate for accommodating a display board between the reflector and the light guide plate. The light from the light source is incident onto the inclined faces of the troughs and reflected thereby toward the reflector. The troughs have different depths whereby the inclined faces thereof are of different surface areas for reflecting different amount of light in order to provide a uniform brightness over the whole module.

Abstract: An electroluminescent clock is disclosed, wherein light emitting dots are installed on the back side of a transparent plate and ring around and beneath luminous markers, whereby when the light emitting dots are enabled, the luminous markers can be presented with uniform lighting to allow a user to see the clock time in the darkness and even from a distance. The night light feature is further enhanced by a special design that creates a soft visual effect on the dial of the clock for easy recognition of clock time.

Abstract: A surface light source device comprises a light guide plate having an emission face and, opposite with the emission face, a back face which is provided with a great number of micro-reflectors, for example, shaped like pyramids and a fine-unevenness surface is formed among the micro-reflectors. The light guide plate has an incidence face through which an illumination light is introduced into the light guide plate to be then being emitted from the emission face with the help of the micro-reflectors and the fine-unevenness surface. Each micro-reflector has at least a pair of slopes which meet each other as to form a ridge that gets closer with an increasing distance from the incidence face. A large part of an inner propagation light is inner-reflected twice by the slopes successively and direction-converted as to be directed to the emission face.

Abstract: A backlight assembly for providing liquid crystal display enhanced brightness of light with a lower consumption of electricity includes a light guide plate having brightness enhancing recesses formed on a bottom surface thereof and light collecting grooves formed on an upper surface thereof. The brightness enhancing recesses efficiently reflect the light having different directions and the light collecting grooves collects the light reflected by the brightness enhancing recesses.

Abstract: There is provided a spread illuminating apparatus to make effective utilization of light emitted from a light source. A light reflection plate is provided along and close to a side surface of a light conductive member opposite to a side surface facing a transparent substrate, and has on a surface thereof a plurality of prismatic projections facing toward the light conductive member and arrayed along the longitudinal direction thereof. A reflection layer is formed on the projections. Light having penetrated inclined walls at the light conductive member is reflected by means of the reflection layer along the optical axis to be effectively utilized.

Abstract: Disclosed are an illumination device capable of improving an optical efficiency of a light generated from a light source and a reflection type liquid crystal device using the illumination device. Between at least one light source and a first light guiding plate, which is provided to uniformly project the light incident from a first side towards a second side, a second light guiding plate for projecting the incident light towards the first side of the first light guiding plate is provided. A distance between a light projecting portion of the second light guiding plate and a light reflecting portion opposite the light projecting portion becomes narrow as an amount of light flux of the light emitted from at least one light source decreases. Accordingly, the light efficiency can be improved by increasing the probability of variation in optical routes for the light generated from each light source, though the number of the light sources disposed at a side of the second light guiding plate is increased.

Abstract: A light guide plate includes a first surface having a light incident surface and a light reflect surface, a second surface facing the first surface, through which the reflected light exits, a first edge surface connected between edges of the light reflect surface and the second surface, and a second edge surface connected between edges of the light incident surface and the second surface, being opposite to the first edge surface. A light source is disposed on the light incident surface. A light guide plate may also include a stepped edge portion formed at a marginal area of the light guide plate on which a light source is combined. The stepped edge portion includes a light incident surface, a light reflect surface, an upper surface through which the reflected light exits the light guide plate, and a first edge surface connected between edges of the light reflect surface and the upper surface, being opposite to the stepped edge portion.

Abstract: This invention provides a planar lighting structure having a light guide plate with inverted V pattern constituted by two wedge light guide plate in order to increase illumination of the planar lighting structure.

Abstract: Optical assembly includes a light emitter and a film through which light passes from the light emitter. The film has a uniform or variable pattern of individual deformities of well defined shape that are projections or depressions on or in one or more surface areas of the film. The deformities are quite small in relation to the width and length of the film. At least some of the deformities may have two or more surfaces that come together to form a ridge having a total length that is quite small in relation to the width and length of the film.

Abstract: A light control sheet suitable for direction-controlling an angularly extending oblique input light, surface light source device and LCD using the light control sheet. A light control sheet is disposed along an emission face of a light guide plate direction-controls main and subsidiary light fluxes to cause them to be emitted toward a desired direction. Main beam S1 emitted from the emission face transmits (with a small refraction) through a first face, being inner-reflected (total reflection) by a first slope region and then outputted from a light output face (SS1). First subsidiary beam T1 transmits (with a small refraction) through the first face, being inner-reflected (total reflection) by a second slope region and then outputted from the light output face (TT1).

Abstract: A light guide plate (2) into which light beams are introduced from a light source (41) includes an incident surface (20) receiving the light beams from the light source; a light emitting surface (22) transmitting light beams outwardly; a bottom surface (21) opposite the light emitting surface for reflecting the light beams to the light emitting surface; and a plurality of sidewalls (24, 26, 28) perpendicular to the light emitting surface. The sidewalls have frosted surfaces for reflecting the light beams to assure output of the light beams through the light emitting surface.

Abstract: A backlight assembly for a liquid crystal display that may include multiple light guides, reflector materials, and light sources of multiple wavelengths, and that may blend light colors to create a balanced illuminating instrument light of uniform brightness.

Abstract: A surface light source device of side light type has a guide plate, a primary light source for supplying illuminating light through an incidence surface, first and second edges at which major surfaces respectively intersect the incidence surface, and one or plural additive members arranged in direct contact with the emission surface and/or the back surface thereon in the vicinity of the first edge and/or the second edge. At least one of the additive members has a shield for preventing illuminating light from being incident to the first or second edge. For example, the shield includes absorptive areas formed on the additive members. Each of the absorptive areas is formed so that each of the absorptive areas crosses the first or second edge. A distal end of a reflector arranged in the primary light source or frame blocks incidence of light to the first and/or second edge. The light incidence block to each edge prevents luminance irregularities in the form of a bright line.

Abstract: The present invention generally relates to an improved light module with LED light source for LCD panel. The edge surfaces of light-receiving and/or light-emitting of LGP and/or LGS are coated with the mixed fluorescent powder layer and the white light with triple wavelength is made by the light rays emitted from UV LED to excite the mixed fluorescent powders. It could replace the white light LED with double wavelength of Nichia to reduce the production cost and increase the color performance of LCD.

Abstract: The present invention generally relates to an improved light module with LED light source for LCD panel. The LGP and/or LGS have the well-mixed fluorescent powders and the white light with triple wavelength is made by the light rays emitted from UV LED to excite the well-mixed fluorescent powders. It could replace the white light LED with double wavelength of Nichia to reduce the production cost and increase the color performance of LCD.

Abstract: An apparatus and method sensing the absolute position of a gauge. A pointer having a predefined rotation with a circular travel pattern. At least one light emitting diode that generates an optical signal. An optical sensor placed in a fixed position along the circular travel pattern of the pointer. A pointer driver for driving the pointer.

Abstract: Light emitting panel assemblies include in one form of the invention a light emitting panel member made of a transparent resiliently deformable elastomeric material that absorbs impact without breakage for use in automotive lighting applications of various types. In another form of the invention, a rigid light emitting panel member may be used with dome switches for switch area lighting or to backlight control buttons/key pads. Also, a rigid light emitting panel member may be used as a structural member, and two or more such light emitting panel members may be stacked together and used to light an instrument panel or the like.

Abstract: A light guiding plate guides light from a light source and irradiates the light onto a display portion. The light guiding plate has an incidence plane, an opposite end plane opposite to the incidence plane, an exit plane facing the display portion, and a reflection-exit plane opposite to the exit plane. A plurality of grooves are formed on the reflection-exit plane. The depth of the grooves monotonously increases from the incidence plane toward the opposite end plane. Each groove is defined by intersecting first and second planes. In each groove, the angle defined by the first plane and the exit plane is substantially equal to that of the other grooves. In each groove, the angle defined by the first plane and the second plane is substantially equal to that of the other grooves. This waveguide increases the brightness and improves the uniformity of brightness distribution.

Abstract: An LED-based backlighting system that provides excellent brightness and homogeneity suitable for high performance multi-color and high resolution portable displays such as for PDAs and cell phones. Several different but similar embodiments are disclosed. Some are suitable for use with multiple LEDs and some for use with a single LED. In a first such embodiment, multiple LEDs are located adjacent the input edge of a light pipe. The input edge contains fixed pitch grooves to propagate the LED light in a direction that is substantially angled toward the bottom surface of the light pipe along its entire area. The light pipe bottom surface also has grooves for altering the direction of the LED light toward the upper surface of the light pipe where it exits the light pipe toward a viewer. The exterior of the exit surface of the light pipe receives a light shaping diffuser (LSD) and an optical film.

Abstract: Land portions to which the spot-like light source is soldered are provided at the end of the FPC, whereby the light emitting surface of the spot-like light source is aligned to the side of the FPC, that is, the FPC does not protrude from the light emitting surface. The spot-like light source mounted on the FPC is disposed close to the light conductive bar with its light emitting surface facing the end surface of the light conductive bar. Since the FPC does not exist ahead of the light emitting surface, the FPC does not overlap the end portion of the light conductive bar, so that light rays emitted from the light emitting surface do not irradiate the FPC.

Abstract: An illuminated interior article system (10) which can be used as a part of a vehicle interior lighting system and which includes a branching optical waveguide (12) and a vehicle interior article (14) positioned relative to waveguide such that the illuminating light exiting the waveguide at its junction (16) illuminates the vehicle interior article. The branching waveguide (12) has a stem (18), first and second branches (20,22), and the junction (16) that couples the stem to each of the branches. The first and second branches (20,22) extend away from the junction (16) at an obtuse angle relative to the stem (18) and the junction includes one or more optical features positioned at the junction such that a portion of the light traveling through one or more of the waveguide sections impinges upon the optical feature(s), with the optical feature(s) redirecting the impinging light out of the waveguide at the junction to thereby provide illuminating light from the junction.

Abstract: An instrument panel includes a transparent base board interposed between an indicator board on which indicator needles are movably mounted and a transparent cover. The base board defines a number of recesses for respectively and movably accommodating the indicator needles therein. Patterns, such as characters, digitals, scales and figures, are formed on the base board by means of CO2 etching. The base board defines a number of slots in an end thereof for receiving illuminators, such as light emitting diodes, which give off lights of different colors and intensities. The illuminators are connected to and controlled by a control circuit. A sensor is mounted to an automobile for detection of an operation parameter of the automobile and applies the operation parameter to the control circuit.

Abstract: There is provided a planar light source unit having a light pipe and a point light source, the light pipe being constituted by a plate-like body having upper and lower surfaces and a side surface serving as an incident surface on which incident light is made to exit from the lower surface through light exit means formed on the upper surface, the light exit means being disposed to face at least one virtual center on or outside the incidence side surface, the incident light made to exit from the upper or lower surface being transmitted to exit from the lower or upper surface through the plate-like body. There is also provided a reflection type liquid-crystal display device having a planar light source unit and a liquid-crystal panel including a reflection layer, the point light source being disposed in the virtual center or between the virtual center and the incidence side surface.

Abstract: A polarized light source device comprises a light source, a reflector, a transparent substrate, an antireflection layer, and a plurality of metal grid wires. The reflector surrounds the light source for reflecting the light, and has an opening for emitting the light. The transparent substrate is disposed at the opening. The antireflection layer is disposed on the transparent substrate. The metal grid wires are disposed on the antireflection layer for transmitting the light with a predetermined polarization therethrough.

Abstract: The present invention provides a liquid crystal display apparatus having a high brightness and a less number of constituent parts. By forming a plurality of dots each constituted by a small projecting portion or a small recess portion for changing a light at a predetermined angle from an incident surface of a light conductor plate toward a direction of a transmitting surface and properly controlling an angle of incline of a cross section, it is possible to irradiate an illuminating light having a suitable angle distribution from a light emitting surface toward a display element, thereby improving a brightness of the liquid crystal display apparatus.

Abstract: An illuminated electric part includes a manipulating shaft which is rotatable and is stable at least at two points. The manipulating shaft is light-transmissive and includes a pictograph portion which is illuminated at a top portion thereof. The illuminated electric part includes a light emitting element which is arranged at a side of the manipulating shaft. The manipulating shaft includes side faces which constitute light incident faces in directions orthogonal to an optical path from the light emitting element at respective stable points and, at the same time, includes a conical light reflecting face having a downwardly extending top at a side opposite to the incident faces.

Abstract: A lock device control element that emits light. The light emitting lock device control element may be used in combination with an electronic device.

Abstract: A liquid crystal display device having a light guide plate and a light source disposed on one of side surfaces of the light guide plate so that external light is transmitted through the light guide plate and enters a liquid-crystal display portion. A plurality of dots each constituted by a small recess or protrusion portion reflecting light from the light source toward the liquid crystal display portion are formed in or on another surface of the light guide plate opposite to the liquid crystal display portion. Each of the dots have a substantially V-shape in section with an inclination angle of the section being in a range of 35° to 43°.