JP6243222B2 - Vehicle lamp - Google Patents

Description

  The present invention relates to a lamp mounted on a vehicle such as an automobile, and more particularly to a vehicle lamp suitably applied to a headlamp using a surface light emitting element as a light source.

  As an automobile headlamp, a lamp using a surface light emitting element such as a chip-type LED as a light source has been proposed. In Patent Documents 1 and 2, a plurality of surface-emitting LEDs are used as light sources, and the light-emitting surfaces of these LEDs are enlarged and projected in front of the host vehicle by an irradiation lens (also referred to as a projection lens) to obtain a required light distribution. A lamp has been proposed. In recent years, surface-emitting LEDs with high luminous intensity have been provided, and lamps comprising a lamp unit using one surface-emitting LED as a light source have been proposed.

JP 2005-85548 A JP 2004-327188 A

  By the way, as described in Patent Document 1, the surface-emitting LED is often configured to supply power by providing electrodes on the back surface and the front surface of the LED chip. Therefore, although specific examples will be described later, it may be necessary to dispose an electrode in a partial region of the light emitting surface, and the emitted light is not emitted from the region where the electrode is disposed. A part of the surface becomes a non-light emitting region. In a lamp using a surface-emitting LED having such a non-light emitting area as a light source, a region where the luminous intensity and the amount of light are reduced corresponding to the non-light emitting region appears in the region irradiated with light from the lamp. Light distribution may not be obtained. In particular, if the area where the luminous intensity and the amount of light are reduced is an area near the lamp optical axis, in other words, an area where the headlamp is used to irradiate the far front area of the vehicle, the visibility of the far front area of the vehicle is reduced. Therefore, it is not preferable in terms of safe driving.

  An object of the present invention is to provide a vehicular lamp that can improve the visibility of a front area of a host vehicle, particularly a far front area, even in a lamp using a light emitting element having a non-light emitting area on a light emitting surface as a light source. Is.

The present invention uses a light- emitting element having a non-light-emitting region that shields light in a partial region of a light-emitting surface that emits light as a light source, and performs light irradiation with a predetermined light distribution on a set lamp optical axis. The light-emitting element includes a light-emitting element on a side where the non-light-emitting region of the light-emitting surface does not exist and is close to or close to the optical axis of the lamp, and a side where the non-light-emitting region exists is located away from the lamp optical axis. It is characterized by being arranged.

The present invention also provides a predetermined light distribution by reflecting light emitted from a light source at a focal position and a light emitting element in which a non-light emitting region that blocks the light exists in a partial region of a light emitting surface that emits light. The light emitting element is arranged such that a side where the non-light emitting area of the light emitting surface does not exist coincides with or is close to the focal point, and a side where the non light emitting area exists is spaced apart from the focal point. It is characterized by being.

  In the present invention, when the predetermined light distribution is a low beam light distribution having a cut-off line, the light-emitting element has a side where the non-light-emitting region of the light-emitting surface does not exist is directed to the cut-off line side, and the non-light-emitting element The side where the region exists is disposed so as to face the side away from the cut-off line.

  The light-emitting element in the present invention is, for example, a surface-emitting type semiconductor light-emitting element having a light-emitting surface, and the non-light-emitting region is generated by an electrode disposed on the light-emitting surface. For example, the light-emitting surface of the light-emitting element is rectangular, and the non-light-emitting region is generated at one corner, and the corner of the diagonal position of the non-light-emitting region or the side including the corner is the lamp light. It is coincident with or close to the axis.

  According to the present invention, the side of the light-emitting surface where the non-light-emitting region does not exist has a higher luminous intensity (also referred to as the amount of emitted light but is referred to as the luminous intensity) than the side where the non-light-emitting region exists. By directing the higher side toward the lamp optical axis side or the focal side, it is possible to increase the light irradiation luminous intensity in the lamp optical axis side region of the light distribution, that is, the far front region of the vehicle, thereby improving the visibility. Since the side where the non-light emitting area exists irradiates the immediate area of the vehicle, even if the light irradiation intensity of the immediate area is lowered, the influence of the decrease in visibility is small. For example, in the case of low beam light distribution with a cut-off line, by directing the side where the non-light-emitting area of the light emitting surface does not exist to the cut-off line side, the light irradiation intensity in the vicinity area of the cut-off line is increased, and The visibility of the front area can be improved.

  According to the present invention, when a light-emitting element in which a non-light-emitting region is generated on the light-emitting surface by a power feeding electrode is applied, the side on which the electrode is not disposed is directed toward the lamp optical axis or the cut-off line side. Set up. In addition, when the light emitting surface is rectangular and a non-light emitting area is generated at one corner, the corner at the diagonal position of the corner or the side including the corner is placed on the lamp optical axis or cut-off line side. By disposing toward the front, the visibility of the far front region can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of a motor vehicle provided with the headlamp of embodiment of this invention, and the enlarged schematic block diagram of a headlamp. The longitudinal cross-sectional view of a unit lamp, and the fragmentary view which looked at LED for demonstrating the arrangement | positioning position of LED from the downward direction. The schematic perspective view which shows the structure of LED, and its mounting state. The figure which looked at mounted LED from the front lower direction. The schematic diagram explaining the low beam light distribution by the lamp unit of embodiment. The schematic diagram explaining the low beam light distribution for a comparison. The longitudinal cross-sectional view of the unit lamp of a modification, and the partial view which looked at LED for demonstrating the arrangement | positioning position of LED from upper direction. The schematic diagram explaining the low beam light distribution by the lamp unit of a modification.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of an embodiment in which the present invention is applied to a headlamp (headlight) of an automobile. Headlamps L-HL and R-HL are arranged on the left and right of the front part of the car body of the car CAR. These headlamps L-HL and R-HL have a single reflector type lamp unit in the lamp housing 2 mounted on the vehicle body, as shown in the lower part of FIG. 1 in the schematic configuration of the left headlamp L-HL. 1 is decorated. The lamp housing 2 includes a lamp body 21 and a translucent front cover 22 attached to the front opening of the lamp body 21. Light emitted from the built-in lamp unit 1 is transmitted through the front cover 22. Light is emitted toward the front of the car CAR.

  The lamp unit 1 has a configuration in which a plurality of unit lamps, in FIG. 1, nine unit lamps 10 are arranged in a horizontal row and integrated, and among these unit lamps 10, an appropriate number of unit lamps 10, FIG. Although not specified in 1, the six unit lamps 10 are configured as lamps that perform light irradiation with a low beam light distribution. The other three unit lamps 10 are configured as lamps that perform illumination with a high beam distribution, that is, lamps that irradiate a front region that is not irradiated with the low beam distribution, and the six unit lamps with the low beam distribution. At the same time as turning on the light 10, the three unit lamps 10 are turned on to perform light irradiation with high beam light distribution.

  A lamp optical axis Lx is defined in advance for the lamp unit 1, and FIG. 2A is a vertical (vertical) sectional view of one unit lamp 10 along the lamp optical axis Lx. The unit lamp 10 includes a surface-emitting LED 11 as a light source, and a reflector 12 that mounts and supports the LED 11 and reflects light emitted from the LED 11 forward. The reflector 12 includes a flat base portion 13 extending in a direction along the lamp optical axis Lx, and a main reflector portion 14 extended in a curved state from the rear end of the base portion 13 downward or forward. It has. Although not shown in the drawing, at least the main reflector portion 14 of the reflector 12 is formed with a light reflecting film such as aluminum on the surface of a resin material.

  The main reflector section 14 is formed in a paraboloid shape with the lamp optical axis position F set on the base section 13 as a focal point, and the light emitted from the LED 11 is transmitted through the main reflector section 14 to the own vehicle. Reflect toward the front of the. The lamp optical axis position F is a position where the lamp optical axis Lx bent by reflection at the main reflector portion 14 intersects the base portion 13. The base unit 13 and the main reflector unit 14 of the nine unit lamps 10 are integrated in a state where they are arranged in the horizontal direction, that is, in a direction orthogonal to the lamp optical axis Lx. The reflector 12 is configured as one composite reflector.

  In the reflector 12, the light reflecting surfaces of the main reflector portions 14 of the unit lamps 10 are formed in curved surfaces having the same or appropriately different curved surface shapes and surface directions. The light reflection characteristics at the reflector section 14 are made different from each other, and the low beam distribution and the high beam distribution are realized as described above by superimposing or combining these reflection lights.

  The LED 11 is mounted and supported on the lower surface of the base portion 13 with the light emitting surface facing downward. FIG. 3 is a schematic perspective view in which the LED 11 is turned upside down, in which an N-type cladding layer 111, an active layer 112, and a P-type cladding layer 113 are laminated. An N electrode 114 is formed as a back electrode almost on the entire bottom surface of the N-type cladding layer 111. A P electrode 115 is formed as a surface electrode on a part of the upper surface of the P-type cladding layer 113. Here, the LED 11 is configured as a chip having a square planar shape, and the P electrode 115 is arranged in one corner of the four corners of the P-type cladding layer 113 having a square shape with a required area. It is installed.

  The LED 11 is mounted on an elongated printed wiring board 15 extending in the length direction of the lamp unit 1. FIG. 2B is a partial view of the LED 11 as viewed from below. A conductive film having a required pattern is formed on the surface of the printed wiring board 15, and the N electrode 114 of the LED 11 is The P electrode 115 is fixed to a part of the ground conductive film 151 while being electrically connected by solder or the like, and the P electrode 115 is electrically connected to a part of the power supply conductive film 152 by a bonding wire 153. In addition, the nine LEDs 11 provided corresponding to the nine unit lamps 10 correspond to the lamp optical axis positions F of the main reflector portions 14 of the unit lamps 10, respectively. It is mounted on the plate 15.

  In the LED 11, the active layer 112 emits light by supplying power between the N electrode 114 and the P electrode 115 via the printed wiring board 15, and the emitted light is emitted from the surface of the P-type cladding layer 113, that is, from the LED 11. The light is emitted from the chip surface (the upper surface in FIG. 3). Therefore, the upper surface of the LED 11 is configured as the light emitting surface B. At this time, since the P electrode 115 formed in a partial region of the light emitting surface of the LED 11 does not transmit light, no light is emitted from the region where the P electrode 115 is disposed. It becomes the non-light-emitting region X on the light-emitting surface. Therefore, the luminous intensity distribution of the light emitted from the light emitting surface B of the LED 11 is substantially uniform luminous intensity over the entire area of the light emitting surface B, but the luminous intensity of the non-light emitting region X where the P electrode 115 is formed is The luminous intensity is lower than other regions or is close to zero.

  FIG. 4 is a view of the LED 11 mounted on the base portion 13 via the printed wiring board 15 as viewed from the front lower side of the lamp. When the LED 11 is mounted on the lower surface of the base portion 13, the side where the non-light emitting area X of the light emitting surface B of the LED 11 does not coincide with the lamp optical axis position F, in other words, the focal point F of the main reflector portion 14. The position where the non-light-emitting region X exists is disposed at a position far from the lamp optical axis position F, that is, the focal point F. Here, the center of one side including the corner on the side where the non-light emitting region X does not exist is disposed at the focal point F, and the opposite side including the corner of the non-light emitting region X is on the rear side of the lamp. LED11 is arrange | positioned so that it may face.

  Therefore, in the lamp unit 1, as shown in FIG. 2B, nine LEDs (only three are shown in the figure) 11 are opposite to the non-light emitting area X of the light emitting surface B. The side is disposed toward the front of the lamp, and the opposite side portion is disposed along a reference line Lb extending through the focal point F in a direction orthogonal to the lamp optical axis Lx. In addition, each LED 11 has a side where the non-light emitting region X exists directed toward the rear of the lamp.

  According to the lamp unit 1, when the LEDs 11 of the six unit lamps 10 corresponding to the low beam distribution are caused to emit light and the unit lamps 10 are turned on, the light emitted from the LEDs 11 is transmitted to the main reflector unit 14. The light is reflected and transmitted through the front cover 22 of the lamp housing 2 to irradiate the front area of the automobile CAR. As described above, since each main reflector portion 14 of each unit lamp 10 is formed in a predetermined curved surface, the light reflected by each main reflector portion 14 is irradiated with light with a predetermined light distribution. The light irradiation with the low beam distribution is performed by superimposing or combining the light beams. At this time, as shown in FIG. 2A, the light Ob emitted from the region of the light emitting surface B on the side where the non-light emitting region X does not exist is reflected toward the region near the lamp optical axis Lx. The light Ox emitted from the region where the light emitting region X exists is reflected toward the region below the lamp optical axis Lx.

  FIG. 5 is a schematic diagram for explaining the low beam light distribution PL by the lamp unit 1, in which the light emitted from the LED 11 is reflected by the main reflector unit 14, and light is irradiated by the low beam light distribution PL in front of the automobile. Is shown. The light emitted from the LED 11 is inverted in the vertical direction and the horizontal direction by reflection at the main reflector portion 14 and is irradiated as a low beam light distribution having a predetermined cutoff line COL. In the figure, V and H are a vertical reference line and a horizontal reference line when the lamp optical axis Lx is the light distribution center. The low beam light distribution PL has a cutoff line COL in the vicinity of the lamp optical axis Lx, and is a light distribution that irradiates a region below the cutoff line COL.

  When this low beam light distribution PL is contrasted with the light emitting surface B of the LED 11, as described in FIG. 2B, the region on the side where the non-light emitting region X does not exist in the light emitting surface B of the LED 11 is the low beam light distribution PL. The region on the side of the light emitting surface B where the non-light emitting region X exists corresponds to the lower region of the low beam light distribution PL. In other words, the upper region including the cut-off line COL of the low beam light distribution PL, that is, the far front region of the own vehicle is irradiated with light from the light emitting surface B having a high luminous intensity on the side where the non-light emitting region X of the LED 11 does not exist. . In addition, the lower region of the low beam light distribution PL, particularly the region corresponding to the front of the vehicle along the lower edge of the low beam light distribution PL is from the light emitting surface B having a relatively low luminous intensity on the side where the non-light emitting region X exists. It is irradiated with light. As a result, a low beam light distribution PL in which the light intensity in the vicinity of the lamp optical axis Lx, that is, the far front region of the automobile is increased, can be realized, which is advantageous in enhancing the visibility in front of the automobile and ensuring safe driving. Become. Note that the light intensity of the area Ax immediately before the own vehicle indicated by hatching in FIG. 5 is lowered by the non-light-emitting area X, but since the distance from the own vehicle is short, a decrease in visibility due to the light intensity is rarely a problem.

  Incidentally, in the lamp unit of this embodiment, as shown in FIG. 6, the side where the non-light emitting area X of the light emitting surface B of the LED 11 exists is directed to the front of the lamp, and this side coincides with or is close to the focal point F. The case where it is mounted on the reflector 12 is a comparison target. In this case, as indicated by diagonal lines in the figure, the light intensity in the region near the lamp optical axis Lx, in other words, the upper region Ax including the cut-off line COL of the low beam light distribution PL, that is, the far front region of the own vehicle decreases. Thus, as described in the section of this specification (Problem to be Solved by the Invention), the visibility in front of the vehicle in the far front region is reduced.

  The lamp unit described above is a configuration example in which the main reflector portion extends below the base portion. However, the lamp unit can be similarly applied to a lamp unit in which the main reflector portion extends above the base portion. FIG. 7A is a longitudinal sectional view of the unit lamp 10 of the lamp unit in which the main reflector portion 14 </ b> A has the reflector 12 </ b> A extended above the base portion 13. Parts equivalent to those in FIG. 2 are denoted by the same reference numerals. In this example, the LED 11 is mounted on the upper surface of the base portion 13 of the reflector 12 </ b> A, and the main reflector portion 14 </ b> A extends upward from the base portion 13. It can be said that the structure of the reflector 12A is a structure in which the reflector 12 in FIG. Needless to say, the LED 11 is disposed on the upper surface of the base portion 13 via the printed wiring board 15.

  The LED 11 is the same as that shown in FIG. 3, and the LED 11 is arranged side by side along the reference line Lb as shown in FIG. Yes. On the other hand, with respect to the arrangement direction of each LED 11, the side of the light emitting surface B of the LED 11 on the side where the non-light emitting region X does not exist is arranged at a position along the reference line Lb or a position close thereto. The corner or side on the side where the non-light emitting region X exists is set so as to be arranged at a position far from the reference line Lb. That is, the side where the non-light emitting area X of the light emitting surface B does not exist coincides with or is close to the lamp optical axis Lx, that is, the focal point F, and the side where the non-light emitting area X of the light emitting surface B exists is separated from the lamp optical axis Lx. It is arranged to face the front side of the lamp.

  In this lamp unit, as shown in a schematic diagram for explaining the low-beam light distribution PL in FIG. 8, the light emitted from the LED 11 is inverted in the vertical direction and the horizontal direction by the main reflector portion 14A, and predetermined cut-off line COL. Is irradiated as a low beam light distribution PL. This low beam light distribution PL has a cut-off line COL in the vicinity of the lamp unit optical axis Lx, and is a light distribution that irradiates a region below the cut-off line COL. Therefore, the LED 11 irradiates the upper region of the low beam light distribution PL with the light Ob from the region facing the back of the lamp where the non-light-emitting region X of the light-emitting surface B does not exist, and the non-light-emitting region X of the light-emitting surface B The light Ox from the region where the light is present is irradiated on the lower region of the low beam light distribution PL.

  Therefore, the upper region including the cut-off line COL of the low beam light distribution PL, that is, the far front region of the automobile is irradiated with light from the light intensity region of the light emitting surface B of the LED 11. Further, the lower region of the low beam light distribution PL, particularly the region Ax along the lower edge, that is, the region immediately before the automobile, has a relatively low luminous intensity from the region where the non-light emitting region X of the light emitting surface B of the LED 11 exists. It is irradiated with light. This increases the luminous intensity of the light irradiation in the region near the lamp optical axis Lx, that is, the far front region of the automobile, which is advantageous in ensuring the safe driving by enhancing the visibility of the automobile in the region.

  Furthermore, although not shown in the drawings, the present invention can be similarly applied to a lamp unit in which the main reflector portion is extended in the left or right direction in the horizontal direction with respect to the base portion. When the main reflector portion is arranged in the left or right direction as described above, the base portion of the reflector is formed in the vertical direction, and the LED is mounted on the elevation surface of the base portion. And the corner | angular part or side part by which the non-light-emission area | region exists among the light emission surfaces of LED is arrange | positioned in the position which corresponds to the lamp | ramp optical axis, or a position close | similar to this. The LED is disposed so that the portion or the side portion is disposed at a position far from the lamp optical axis. Such a lamp unit is also advantageous in increasing the light intensity of light irradiation in the far front area of the automobile and enhancing the visibility in front of the vehicle in that area to ensure safe driving.

  In the above description of the embodiment, the case where the focal point of the reflector coincides with the lamp optical axis has been described. However, the focal point of the reflector does not necessarily coincide with the lamp optical axis. In this case, it is possible to increase the light intensity in an important region of the required light distribution by arranging the LEDs with reference to the focal point of the main reflector for obtaining the required light distribution. In this case, as described in the embodiment, the corner or side of the light emitting surface of the LED where the non-light emitting region exists coincides with the focal point of the main reflector, or the position. The LEDs may be arranged so that the corners or sides on the side where the non-light-emitting region exists are arranged at positions close to each other and at a position far from the focal point.

  Furthermore, the present invention can be applied to a projector-type lamp unit. Since the structure of the projector-type lamp unit is already known, a detailed description thereof will be omitted. However, even in the projector-type lamp unit, basically, the side where the non-light-emitting area does not exist on the light emitting surface of the LED is the lamp light. The side where the non-light-emitting region exists is arranged at a position far from the lamp optical axis.

However, in the projector type lamp unit, the light emitting surface of the LED is illuminated in an upright state by reversal due to reflection by the reflector and reversal by the irradiation lens. It is necessary to appropriately set whether the light is directed to the front side or the rear side of the lamp with respect to the non-light emitting region in accordance with the configuration of each reflector. Further, in the projector type lamp unit, a part of the light emitted from the LED is often shielded by the shade to obtain a low beam light distribution. In this case, the light shielded by the shade is a non-light emitting area on the light emitting surface. It is preferable that the light is emitted from the side to become light. By doing so, it is advantageous to increase the luminous intensity of the light irradiation in the vicinity of the lamp optical axis, that is, the far front area of the automobile, and to improve the visibility in front of the vehicle in the area to ensure safe driving. .

  In the above embodiment, the unit lamp that performs light irradiation with the low beam light distribution among the plurality of unit lamps constituting the lamp unit has been described. However, the unit lamp that performs light irradiation with the high beam light distribution is similarly described. It is possible to apply. In the high beam distribution, the region above the cut-off line of the low beam distribution is generally configured to additionally irradiate the light with the high beam distribution. Is preferably increased. Therefore, the side where the non-light emitting area does not exist on the light emitting surface of the LED is directed to a position coincident with or close to the lamp optical axis, and the side where the non-light emitting area exists is directed to a position far from the lamp optical axis. Thus, it is the same that the direction of the LED is set.

  In the embodiment, one side of the light emitting surface of the rectangular LED is arranged in a direction perpendicular to the lamp optical axis, but the diagonal line of the rectangular LED is arranged in a direction along the lamp optical axis. You may do it. In this case, the corner where the non-light-emitting region exists and the corner at the diagonal position coincide with or be close to the lamp optical axis, and the corner where the non-light-emitting region X exists is located far from the lamp optical axis. It will be arranged like this.

Further, in the LED applied to the present invention, a non-light emitting region may exist in an intermediate portion in the length direction of one side portion of a rectangular light emitting surface. In this case, the opposite side portion of the non-light emitting region is arranged to be coincident with or close to the lamp optical axis, and the side portion where the non-light emitting region exists is arranged away from the lamp optical axis. Furthermore, the LED applied to the present invention may be applied to an LED in which the shape of the light-emitting surface does not have to be rectangular and a non-light-emitting region exists at a part of the light-emitting surface that is biased. That is, regardless of the difference in the shape of the light emitting surface, the side where the non-light emitting area does not exist may be directed toward the lamp optical axis, and the side where the non-light emitting area exists may be directed toward the side away from the lamp optical axis.

  In the lamp unit having a configuration different from that of the reflector-type lamp unit or the projector-type lamp unit, the present invention provides a position where the side where the non-light-emitting area does not exist coincides with the lamp optical axis or the LED light-emitting surface. It goes without saying that the present invention is applied by setting the direction of the LED so that the non-light-emitting region is directed to a position far from the lamp optical axis toward a close position. In addition, the present invention is not limited to a headlamp as long as it is a lamp that performs light irradiation with a required light distribution, and may be a fog lamp or a lamp that lights up in the daytime.

  The present invention can be applied to a vehicle lamp using a light emitting element in which a non-light emitting region that does not emit light exists in a partial region of the light emitting surface as a light source.

1 Lamp Unit 2 Lamp Housing 11 LED (Light Emitting Element)
12,12A reflector (composite reflector)
13 Base part 14, 14A Main reflector part 15 Printed wiring board B Light emitting surface X Non-light emitting area Lx Lamp optical axis F Lamp optical axis position (focal point)
Lb Reference line PL Low beam light distribution COL Cut-off line Ax Low light intensity area

Claims (5)

A lamp that emits light with a predetermined light distribution with respect to a set lamp optical axis using a light emitting element in which a non-light emitting area that blocks the light exists in a partial area of a light emitting surface that emits light. The light emitting element is arranged such that a side of the light emitting surface where the non-light emitting region does not exist coincides with or is close to the optical axis of the lamp, and a side where the non light emitting region exists is arranged away from the lamp optical axis. Characteristic vehicle lamp. A light- emitting element having a non-light-emitting region that blocks the light in a partial region of a light-emitting surface that emits light, and a reflector that reflects light emitted from a light source at a focal position and irradiates with a predetermined light distribution The light emitting element is characterized in that a side where the non-light emitting region of the light emitting surface does not exist coincides with or is close to the focal point, and a side where the non light emitting region exists is arranged away from the focal point. Vehicle lamp   The predetermined light distribution is a low beam light distribution having a cut-off line, and the light-emitting element has a side where the non-light-emitting region of the light-emitting surface does not exist is directed to the cut-off line side, and a side where the non-light-emitting region exists is the The vehicular lamp according to claim 1, wherein the vehicular lamp is directed to a side away from the cut-off line.   The light emitting surface is rectangular, and the non-light emitting area is formed at one corner, and the corner of the diagonal position of the non-light emitting area or the side including the corner coincides with or is close to the lamp optical axis. The vehicle lamp according to claim 3, wherein the vehicle lamp is provided.   The vehicle lamp according to any one of claims 1 to 4, wherein the lamp comprises a reflector type lamp unit or a projector type lamp unit.

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