JP2016207725A - Light emitting diode device - Google Patents

Abstract

A light-emitting diode device that changes a light distribution pattern in an illumination field without giving an observer a sense of incongruity. A plurality of light emitting diode segments includes a support substrate, a light emitting diode array including a plurality of light emitting diode segments disposed on the support substrate, a drive circuit for the light emitting diode array, and a control circuit for the drive circuit. Each of which has a plurality of power feeding structures that are configured by using a continuous semiconductor stack 20 and can inject current independently at different positions, and the drive circuit can independently supply current to the plurality of power feeding structures and control The circuit controls the current supplied to the plurality of power feeding structures of the light emitting diode segments based on the desired light distribution. [Selection] Figure 1-2

Description

  The present invention relates to a light emitting diode device, and more particularly, to an arrayed light emitting diode device including a plurality of light emitting diode segments arranged in a planar light emitting region.

  In recent years, in vehicle headlamps, attention has been paid to a technology (called ADB: Adaptive Driving Beam) that controls the light distribution shape in real time depending on the situation ahead, that is, whether there is an oncoming vehicle or a front vehicle, and its position. Has been.

According to this technique, for example, when an oncoming vehicle is detected during traveling with a light distribution shape, i.e., a high beam, light that is directed only to the area of the oncoming vehicle among the areas irradiated to the headlamps. It becomes possible to reduce in real time. It is possible to always give the driver a field of view close to a high beam, while preventing oncoming vehicles from giving glare.
Also, headlight systems (called Adaptive Front-lighting System etc.) that improve the light distribution intensity in the traveling direction by adjusting the light distribution in the traveling direction according to the steering angle of the steering wheel are becoming common. .

  Such a light distribution variable type headlamp system creates, for example, an arrayed light emitting diode device in which a plurality of light emitting diode (LED) segments are juxtaposed in an array, and each light emitting diode is turned on / off (on / off). ) Can be realized in real time.

  An array of a plurality of LED segments arranged in a matrix and independently controllable for lighting, and a projection lens disposed on an optical path of light emitted from the array of LED segments, and lighting the array of LED segments There has been proposed a vehicular headlamp device configured to form a predetermined light distribution pattern ahead by controlling the pattern (for example, Patent Document 1).

  FIG. 8A is a side view of a main part of a vehicle headlamp in which a plurality of light emitting diodes (LEDs) 212 are arranged in a matrix on a support substrate 211 having a heat dissipation mechanism and a projection lens 210 is arranged in front. It is.

  FIG. 8B is a front view of a plurality of LEDs 212 arranged in a matrix. An optical system in which a light source including a plurality of LEDs arranged in a matrix (hereinafter referred to as “matrix LED”) is directed to the front of the vehicle and a projection lens is disposed in front of the light source projects the luminance distribution of the LEDs forward. .

  FIG. 8C is a block diagram illustrating a schematic configuration of the headlamp system. The headlamp system 200 includes left and right vehicle headlamps 100, a light distribution control unit 102, a front monitoring unit 104, and the like. The vehicle headlamp 100 includes a light source composed of matrix LEDs, a projection lens, and a lamp body that accommodates them.

  The front monitoring unit 104 to which various sensors such as the in-vehicle camera 108, the radar 110, and the vehicle speed sensor 112 are connected performs image processing on the imaging data acquired from the sensors, and the front vehicle (an oncoming vehicle or a preceding vehicle) or other on-road brightness. Objects and lane markings (lane marks) are detected, and data necessary for light distribution control such as their attributes and positions are calculated, and the calculated data is distributed via the in-vehicle LAN or the like to the light distribution control unit 102 and various in-vehicle devices. Called to.

  The light distribution control unit 102 to which the vehicle speed sensor 112, the rudder angle sensor 114, the GPS navigation 116, the headlight switch 118, and the like are connected has an attribute (oncoming vehicle, preceding vehicle) of the road glittering object sent from the front monitoring unit 104. The light distribution pattern corresponding to the traveling scene is determined based on the vehicle (reflector, road illumination), its position (front and side) and the vehicle speed.

The present inventors epitaxially grow a device structure layer in which an n-type GaN layer, an active layer, and a p-type GaN layer are stacked on a sapphire growth substrate, for example, and form a p-side reflective electrode having an opening on the p-type GaN layer. Forming and etching the p-type GaN layer and active layer in the opening to expose the n-type GaN layer, forming an n-side electrode on the n-type GaN layer, and forming a p-side electrode on the support substrate having wiring; The side electrode is adhered, the growth substrate is removed by laser lift-off, etc., and the LED having a structure in which the n-type GaN layer is a light emitting surface is converted into white and verified. Even if the GaN layer is replaced with another nitride semiconductor (for example, In _x Ga _y Al _1-xy N (where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1)) layer Good (for example, Patent Document 2). In this configuration, the n-side electrode and the p-side electrode are formed on the same surface and can be easily connected to the wiring board, and output light can be irradiated from the exit surface where no electrode is present.

JP 2013-54849 A JP, 2014-120511, A

  When ADB or AFS is performed in a vehicle headlamp or the like, each light emitting segment is controlled only on / off. During operation, each segment suddenly turns on and off. If the segment-corresponding region in the field of view suddenly turns on and off, the driver will feel a sense of incongruity (a feeling that the field of view changes dramatically).

  It is desirable to change the light distribution pattern of the illumination field without giving the viewer a sense of incongruity.

The inventors of the present invention have devised a structure in which a plurality of power feeding units capable of injecting current independently into one segment are provided for a plurality of segments constituting the headlamp so that a portion for injecting current can be selected. did. The semiconductor layers in one segment are continuous and can transport carriers. For example, four regions are set in one segment, and a power supply unit is provided for each region, and current is supplied to any power supply unit. That is,
A support substrate;
A light emitting diode array including a plurality of light emitting diode segments disposed on the support substrate;
A driving circuit for the light emitting diode array;
A control circuit for the drive circuit;
Including
Each of the plurality of light emitting diode segments is configured using a continuous semiconductor stack, and has a plurality of power feeding structures capable of injecting current independently at different positions,
The drive circuit can supply current independently to the plurality of power feeding structures,
The control circuit controls a current supplied to a plurality of power feeding structures of the light emitting diode segment based on a desired light distribution.
A light emitting diode device is provided.

  As the current leaves the injected power supply, the supplied carriers decrease and form a luminance gradation. By changing the power feeding unit for injecting current, gradation can be moved, lighting can be smoothly turned on and off within one segment, and the uncomfortable feeling (paraparade) felt by the driver can be reduced.

,as well as 1A and 1B are cross-sectional views of semiconductor stacks that can constitute light emitting diodes and their equivalent circuit diagrams, and FIGS. 1C, 1D, and 1E are electrodes in which a plurality of regions are set in the semiconductor stack and current can be supplied independently. Cross-sectional view of structure and two equivalent circuit diagrams, FIGS. 1F and 1G are a cross-sectional view and plan view of one segment of the light emitting diode of the first structural example, and FIGS. 1H and 1I are light emitting diodes of the light emitting diode of the second structural example. It is sectional drawing and planar structure figure for 1 segment. , ,as well as 2A and 2B are a cross-sectional view and a plan view of a structure in which a semiconductor stack is grown on a growth substrate and a p-side electrode having an opening is formed on the upper surface, and FIG. 2C is a p-type semiconductor layer in the opening, 2D, 2E, 2F, and 2G are cross-sectional views and plane views of a structure corresponding to one segment in which four cathode electrodes are shared and four independent anode electrodes are provided. FIG. 2F is a sectional view taken along the line IIF-IIF in FIG. 2E, and FIG. 2G is a sectional view taken along the line IIG-IIG in FIG. 2E. It is sectional drawing which follows a line. 3A and 3B are an equivalent circuit diagram of a drive circuit of the light emitting diode array and a timing chart of a time division control signal. 4A, 4B, 4C, and 4D are plan views showing an operation example in which gradation control is performed on four segments. 5A to 5H are plan views illustrating an operation example in which gradation control is performed on a plurality of segments in an oblique direction. 6A and 6B are equivalent circuits of a drive circuit using two and three time-division switching circuits. 7A and 7B are a plan view and an equivalent circuit diagram showing a modification example of the segment arrangement, FIG. 7C is a plan view showing a modification example of the segment shape, and FIG. 7D shows three cathode side wirings and three anode side wirings. It is the schematic which shows the structure to be used. 8A, 8B, and 8C are a side view of a main part of a vehicle headlamp, a plan view of a light-emitting diode array, and a block diagram of a vehicle headlamp system according to the prior art.

10 growth substrate, 20 semiconductor stack, 22 n-type semiconductor layer, 23 active layer, 24 p-type semiconductor layer, 30 p-side electrode, 40 n-side electrode, 32, 42 adhesive layer, 62 lower wiring 64 upper wiring 72 supporting substrate , LED light emitting diode, OP opening.

  FIG. 1A shows a semiconductor stack 20 that includes an n-type semiconductor layer 22, an active layer 23, and a p-type semiconductor layer 24, and can constitute a light emitting diode (LED). Each semiconductor layer 22, 23, 24 is continuous in the horizontal direction in the figure. When producing a plurality of light emitting diodes from this configuration, the semiconductor stack 20 is usually divided into a plurality of portions. Then, it becomes a plurality of independent light emitting diode structures.

  FIG. 1B shows one equivalent circuit of the semiconductor stack 20 of FIG. 1A. If the configuration shown in FIG. 1A is divided into two left and right regions, they can be considered as light emitting diodes LED1 and LED2, respectively. Since each semiconductor layer 22, 23, 24 is continuous, it is considered that they are connected by lateral resistances R1, R2, R3. The lateral resistance R2 of the active layer 23 is considerably larger than the lateral resistance R1 of the n-type semiconductor layer 22 and the lateral resistance R3 of the p-type semiconductor layer 24, and will not be described below.

  In FIG. 1C, an opening that penetrates the p-type semiconductor layer 24 and the active layer 23 and exposes the n-type semiconductor layer 22 is provided in the left region and the right region, respectively, and the p-side electrode is formed on the p-type semiconductor layer 24. A structure in which n-side electrodes 40-1 and 40-2 are formed on 30-1 and 30-2 and the n-type semiconductor layer 22 is shown. The p-side electrode 30 and the n-side electrode 40 are disposed on the lower surface side of the semiconductor stack 20, and the n-type semiconductor layer 22 disposed on the upper side is not covered with the electrode.

  FIG. 1D is an equivalent circuit diagram of one of the structures of FIG. 1C. The p-side electrodes 30-1, 30-2 and the n-side electrodes 40-1, 40-2 are connected to the left and right light emitting diodes LED1, LED2. The n-type semiconductor layer 22 and the p-type semiconductor layer 24 of the two light emitting diodes LED1 and LED2 are connected by lateral resistances R1 and R3.

  The electrode pair (30-1, 40-1) mainly supplies current to the left side light emitting diode LED1, and the electrode pair (30-2, 40-2) mainly supplies current to the right side light emitting diode LED2. Through the lateral resistances R1 and R3, the left electrode pair (30-1, 40-1) to the right light emitting diode LED2 and the right electrode pair (30-2, 40-2) to the left light emitting diode. Some current is also supplied to the LED 1.

  The electrode pairs 30-1 and 40-1 and the electrode pairs 30-2 and 40-2 constitute a power feeding unit that can supply current independently. However, since the semiconductor layers are continuous and connected by a lateral resistance, when a voltage is applied to the left electrode pair 30-1, 40-1, not only the left light emitting diode LED1 emits light but also the right light emission. Light emission of a luminance distribution having a gradually decreasing gradation occurs from the left end of the diode LED2 to the right side region. When a voltage is applied to the right electrode pair 30-2, 40-2, not only the right light emitting diode LED2 emits light but also a luminance distribution having a gradation gradually decreasing from the right end of the left light emitting diode LED2 to the left side. Luminescence occurs.

  In FIG. 1D, an independent p-side (anode) electrode 30 and n-side (cathode) electrode 40 are formed in each region. Even if one of the anode electrode and the cathode electrode is not an independent electrode, an independent power feeding unit can be configured.

  FIG. 1E is an equivalent circuit diagram when a common anode electrode 30 and separate cathode electrodes 40-1 and 40-2 are connected to two light emitting diodes LED1 and LED2. 1C corresponds to the case where the p-side electrodes 30-1 and 30-2 are continuous p-side electrodes 30. Since the p-side electrode 30 is continuous, the lateral resistance R3 of the p-type semiconductor layer 24 is extremely large as compared with the lateral resistance of the p-side electrode 30, and can be ignored.

  The case where two regions are set in a continuous semiconductor stack has been described above as an example. The number of the plurality of regions is not limited to two. Hereinafter, a case where four regions are set in a continuous semiconductor stack will be described as an example.

  1F and 1G are a cross-sectional view and a plan view of one segment of the light emitting diode of the first structure example. As shown in FIG. 1F, an n-type GaN layer 22, an active layer 23, and a p-type GaN layer 24 are stacked to constitute a semiconductor stack 20. The active layer 23 includes a multiple quantum well structure including, for example, an alternate stack of GaN barrier layers and InGaN well layers.

  As shown in FIG. 1G, the semiconductor stack 20 has four sections AR1, AR2, AR3, AR4. The semiconductor layer is continuous between adjacent sections. 1F, on the surface of the p-type GaN layer, a p-side electrode 30 that functions as a reflective electrode and has an opening in each partition is formed, and the p-type GaN layer 24 and the active layer 23 in the opening are etched. As a result, the n-type GaN layer 22 is exposed. An n-side electrode 40 is formed on the exposed n-type GaN layer 22. The p-side electrode 30 may be continuous in all the sections AR1, AR2, AR3, AR4, or may be separated for each section. In the case of FIG. 1F, each section is separated. The n-side electrode 40 is connected to each section.

  As shown in FIG. 1G, power feeding portions P1, P2, P3, and P4 that can inject current independently are connected to the electrodes 30 and 40 of the four sections AR1, AR2, AR3, and AR4 in one segment, respectively. Each of the four power feeding portions P1, P2, P3, and P4 has an anode wiring and a cathode wiring. In other words, even if four sections are separated, each has a configuration that can function as a light emitting diode. When current is injected into all four sections AR1, AR2, AR3, AR4, almost the entire surface of the segment emits light.

  When current is injected only from the power supply unit of any one of the sections, for example, the power supply section P1 corresponding to the section AR1, the main part of the section AR1 emits light in the same manner, and light is also emitted in the adjacent areas of the continuous sections AR2, AR3, AR4. Propagation causes light emission. As the distance from the main part of the section AR1 decreases, the luminance decreases, and a luminance gradation occurs. That is, a gradation region in which the luminance decreases from the periphery of the section AR1 to the outside is generated.

  Light propagation occurs in all sections AR1, AR2, AR3, AR4 regardless of whether the p-side electrode 30 is continuous or separated, but if it is formed continuously, the n-side of AR1 is further generated. Carriers are also supplied from the electrode 40 toward the p-side electrode 30 of AR2, AR3, AR4. Even in this case, since the carrier density decreases as the distance from the main portion of the section AR1 decreases, the luminance decreases and gradation is generated.

  1H and 1I are a cross-sectional view and a plan view of one segment of the light emitting diode of the second structural example. The point that one segment has four sections AR1, AR2, AR3, AR4 is the same as in the first structure example. The anode-side power feeding units PA1, PA2, PA3, and PA4 are connected to each section, the cathode-side power feeding section PC1 is connected to the sections AR1 and AR2, and the cathode-side power feeding section PC2 is connected to the sections AR3 and AR4.

  Although the power supply unit supplies current from the anode to the cathode, it is possible to configure a power supply unit that can supply current independently even if both the anode and the cathode are not independent. If the four anode-side power feeding units are independent, four independent power feeding units can be configured.

  The semiconductor stack 20 includes an n-type GaN layer 22, an active layer 23, and a p-type GaN layer 24 as shown in FIG. 1H, and has four sections AR1, AR2, AR3, and AR4 as shown in FIG. 1I. The anode-side power feeding parts PA1, PA2, PA3, PA4 connected to the four sections are connected only to the p-side electrode. The cathode-side power feeding part PC1 is connected to the n-side electrodes of the sections AR1 and AR2, and the cathode-side power feeding part PC2 is connected to the n-side electrodes of the sections AR3 and AR4. Since the anode-side power feeding parts PA1, PA2, PA3, and PA4 are independent, a power feeding part that can inject current independently into the four sections can be configured.

  Although the case where the cathode side power feeding unit is configured by the PC1 common to the two sections AR1 and AR2 and the PC2 common to the two sections AR3 and AR4 has been described, it is common to the four sections AR1, AR2, AR3 and AR4. It is good also as cathode side electric power feeding part PC. The n-side electrode 40 may be separated for each of AR1, AR2, AR3, AR4, or may be separated for each of PC1, PC2. Further, as shown in the n-side wiring 41 of FIG. 1H, all the n-side electrodes 40 may be connected to the same wiring layer.

  In addition, when cathode side electric power feeding part PC1 and PC2 are independent, it is good also considering the anode side electric power feeding part as two (A1-A3) and (A2-A4). With the two anode-side power supply units and the two cathode-side power supply units, four power supply units that can supply current independently by time-division driving or the like can be configured.

  2A to 2F show a manufacturing process of a configuration in which one segment has four sections and is connected to two anode-side wirings and two cathode-side wirings on a support substrate. On the semiconductor stack, the cathode electrode is shared and four independent anode electrodes are provided.

  Referring to FIG. 2A, an n-type GaN layer 22, an active layer 23, and a p-type GaN layer 24 are stacked on a growth substrate 10 such as sapphire to form a semiconductor stack 20. A p-type electrode 30 divided into four regions is formed on the p-type GaN layer 24.

  FIG. 2B is a plan view showing patterns of four p-side electrodes 30-1, 30-2, 30-3, and 30-4 formed on the p-type GaN layer 24. FIG. The semiconductor stack is divided into four sections. One p-side electrode 30 common to all sections may be used. Increasing the area of the p-side electrode that functions as a reflective electrode is advantageous for improving the light extraction efficiency. In order to form an n-side electrode, a plurality of openings OP are formed through the p-side electrode 30. The p-side electrode 30 can be patterned by lift-off or etching using a resist mask.

  As shown in FIG. 2C, an opening that exposes the n-type GaN layer 22 through the p-type GaN layer 24 and the active layer 23 from the surface of the p-type GaN layer 24 in the opening OP using an etching mask or the like. Etch.

  As shown in FIG. 2D, an insulating film 36 such as silicon oxide is formed to cover the p-side electrode 30 and the exposed semiconductor surface, and the insulating film 36 on the bottom surface of the opening is etched to expose the n-type GaN layer 22. To do. An n-side electrode 40 is formed on the n-type GaN layer exposed in the opening. An opening exposing the p-side electrode 30 is formed in the insulating film 36. An n-side adhesive layer 42 is formed on the n-side electrode 40, and a p-side adhesive layer 32 is formed on the p-side electrode 30 in each corner portion. Four p-side adhesive layers are formed and connected to the four power feeding units.

  FIG. 2E shows a plan view of the adhesive layers 32 and 42. The common n-side adhesive layer 42 is formed in one segment, and four p-side adhesive layers 32-1, 32-2, 32-3, and 32-4 are formed at four corner portions. The adhesive layer is patterned by lift-off, for example. The semiconductor structure is fixed on the support substrate, the growth substrate is removed, and a fine structure such as a micro cone is formed on the exposed n-type GaN layer 22 surface.

  2F is a cross-sectional view taken along line IIF-IIF in FIG. 2E. As shown in FIG. 2F, two lower wirings 62 extending in a direction perpendicular to the paper surface, for example, are formed on a support substrate 71 such as a Si substrate having an insulating layer 61 such as silicon oxide formed on the surface thereof. Cover with an insulating layer 63 such as silicon. Two lower wirings 62 are formed per segment. A connection hole is formed in the insulating layer 63, and two types of electrically separated upper wirings 64p and 64n are formed. The two wirings 64p are connected to the two adhesive layers (32-1, 32-2) or (32-3, 32-4) on the semiconductor lamination side on the upper surface, and are commonly used for one lower wiring 62 on the lower surface. Connected. The two wirings 64n extend around the wiring 64p in the horizontal direction on the paper surface.

  2G is a cross-sectional view taken along line IIG-IIG in FIG. 2E. Two wirings 64n are connected to the adhesive layer 42 in one segment.

  Refer to FIG. 2E. Two wirings 64n per segment are connected to the upper and lower regions of the adhesive layer 42 and extend in the lateral direction. The two wirings 64p connect the two adhesive layers 32-1, 32-2 and 32-3, 32-4, respectively. The semiconductor laminated structure and the support substrate structure are bonded by thermocompression bonding or the like. The surface of the n-type GaN layer 22 exposed on the upper side is wet-treated with a TMAH (tetramethylammonium hydroxide) aqueous solution or the like to form a fine structure such as a microcone.

  Two anode-side wirings and two cathode-side wirings are provided per segment. Although the four sections cannot be driven simultaneously and in an arbitrary pattern, the four sections are driven in a desired pattern by performing time-division driving or the like.

  3A and 3B show driving examples using a time division switching circuit. It is assumed that the light emitting diode array includes 3 × 3 = 9 segments SEG. Each segment SEG has two anode-side wirings A extending in the vertical direction and two cathode-side wirings C extending in the horizontal direction. Six cathode-side wirings C1 to C6 are connected to three segment rows, and six anode-side wirings A1 to A6 are connected to three segment columns.

  FIG. 3B is a timing chart showing drive signal waveforms of the time division switching circuit 50. The time division switching circuit 50 sequentially supplies drive signals to the six cathode-side wirings C1 to C6. If a pattern signal is applied to the anode side wiring during a period when the drive signal changes to the negative polarity side, the corresponding section is activated and light emission occurs. Six anode-side wirings are arranged in the vertical direction, and a pattern signal for realizing a lighting pattern is supplied at a predetermined timing.

  An example of the operation of the above structure will be described with reference to FIGS. FIG. 4A is a plan view showing the configuration of the ADB element. In the ADB element ADB, for example, tens to hundreds of segments SEG are arranged in a matrix in a horizontally long rectangular region. For simplicity of illustration, the number of segments is shown as 4 × 10. A case where the 4-segment region 45 with a broken line is turned off will be described. If the four segments are turned off at the same time according to the conventional technique, a feeling of strangeness is given.

  As shown in FIG. 4B, as a first step, the currents of the four power feeding units arranged at the center of the four segment region 45 are cut off. The central part of the 4-segment region 45 stops emitting light and changes to a dark part. The surrounding area to which current is supplied is kept in a bright state, and the boundary area is in a gradation state.

  As shown in FIG. 4C, as a second step, the current supply to the power supply units other than the power supply units at the four corners of the 4-segment region 45 is turned off. The region corresponding to the eight power feeding parts surrounding the central region that is initially in the dark state is in the dark state. The area of the four power feeding portions at the corner is kept in a bright state, and the boundary area is in a gradation state.

  As shown in FIG. 4D, as a third step, the current supply to the remaining four feeding parts in the four segment region 45 is cut off. The 4-segment area becomes dark. In this way, the dark region gradually spreads from the center to the periphery, and the boundary between the dark region and the bright region is in a gradation state, so that the light distribution region can be changed smoothly and the uncomfortable feeling given to the observer can be reduced.

  With reference to FIGS. 5A to 5H, the operation of turning off the nine-segment region 47 in an oblique direction will be described. FIG. 5A shows a case where the entire 9-segment region is in a bright state.

  As shown in FIG. 5B, the current supply to the upper right power supply section of the upper right segment of the nine segment region 47 is cut off. The corresponding upper right area is in a dark state surrounded by a gradation area.

  As shown in FIG. 5C, the current supply to the power supply units other than the lower left of the upper right segment of the 9 segment region 47 and the upper right power supply units of the segments adjacent to the left and lower sides is cut off. The area where the current supply is cut off is in a dark state surrounded by the gradation area.

  As shown in FIG. 5D, the current supply to all the power supply units in the upper right segment, the power supply units other than the lower left of the segment adjacent to the left side and the lower side, and the upper right power supply unit of the center, upper left, and lower right segments is cut off. The area where the current supply is cut off is in a dark state surrounded by the gradation area.

  As shown in FIGS. 5E to 5G, the power feeding section that gradually cuts off the current supply is gradually expanded in the lower left direction. In FIG. 5G, the current is supplied only to the lower left power feeding section of the lower left segment. Only the area corresponding to the lower left one feeding section to which the current is supplied is in a bright state surrounded by the gradation area.

  As shown in FIG. 5H, the current supply of the remaining power supply units is also cut off, the current supply of all the power supply units is cut off, and the entire 9-segment region is made dark. In this way, when the 9-segment area is switched while extending the dark state obliquely downward, the light distribution area changes smoothly, and the uncomfortable feeling given to the observer can be reduced. The time division switching circuit is not limited to the case where only one is used.

  6A and 6B are equivalent circuit diagrams showing a drive circuit using two or more time-division switching circuits. Take the case of controlling 3 × 3 segments as an example. In FIG. 6A, the cathode wiring for 1.5 rows is activated by two time-division switching circuits 50-1 and 50-2, respectively. The anode side wiring is also divided into two sets of A1 to A6 and A7 to A12 so that the two time division switching circuits 50-1 and 50-2 are effectively used. In FIG. 6B, a total of three time-division switching circuits 50-1, 50-2, 50-3 are used, one for each column of segments. Although the case where the anode side wiring is continuous in the column direction is shown, it is suitable for higher speed operation if it is divided into three sets for each time division switching circuit.

  Although the embodiments have been described above, these do not limit the present invention. For example, a ZnO light emitting diode may be used instead of the GaN light emitting diode, and the whitening method is not limited to a specific method. Further, another light emitting diode that emits white light, for example, one that expresses white by mixing RGB may be used. The light emitting diode (LED) may be a semiconductor laser. Since the semiconductor laser is also a diode, the LED includes a laser.

  7A and 7B show a case where the areas set in the segment are four areas arranged in one direction (horizontal direction in the figure). Suitable for applications that only perform lateral switching.

  As shown in FIG. 7A, four vertically long sections AR1, AR2, AR3, AR4 are arranged in the horizontal direction in each segment SEG. For example, as shown in FIG. 7B, anode-side power feeding parts PA1, PA2, which can connect the cathodes of four light emitting diodes LED1, LED2, LED3, and LED4 formed by four sections in common and can supply current independently to the anodes. Connect PA3 and PA4.

  In any example, the number of sections is four, but the number of sections may be any number.

  FIG. 7C shows a case where the segment shape is a hexagon. For example, six to three power supply units that can operate independently are connected to each segment. As the shape of the segment that can fill the plane, other triangles are possible.

  FIG. 7D shows a configuration in which three cathode-side wirings C1, C2, C3, and three anode-side wirings are provided, and one cathode-side wiring and one anode-side wiring are combined in each power feeding portion of the light-emitting diode segment. FIG. A plurality of anode-side wirings and a plurality of cathode-side wirings may be provided, and one power feeding unit may be specified by a combination of the anode-side wiring and the cathode-side wiring.

  It will be apparent to those skilled in the art that other various modifications, improvements, combinations, and the like are possible.

Claims (8)

A support substrate;
A light emitting diode array including a plurality of light emitting diode segments disposed on the support substrate;
A driving circuit for the light emitting diode array;
A control circuit for the drive circuit;
Including
Each of the plurality of light emitting diode segments is configured using a continuous semiconductor stack, and has a plurality of power feeding structures capable of injecting current independently at different positions,
The drive circuit can supply current independently to the plurality of power feeding structures,
The control circuit controls a current supplied to a plurality of power feeding structures of the light emitting diode segment based on a desired light distribution.
Light emitting diode device.   2. The light-emitting diode device according to claim 1, wherein each of the plurality of power feeding units includes an anode-side wiring and a cathode-side wiring.   The light emitting diode device according to claim 2, wherein an anode side wiring and a cathode side wiring of each power feeding unit are independent from each other.   The light emitting diode device according to claim 2, wherein at least one of the anode side wiring and the cathode side wiring of each power feeding unit is independent.   The plurality of light-emitting diode segments each have a plurality of anode-side wirings and a plurality of cathode-side wirings, and one power supply unit is specified by a combination of the anode-side wiring and the cathode-side wiring. Light emitting diode device.   The light emitting diode device according to claim 5, wherein each of the plurality of light emitting diode segments is provided with four sections each having a length and a width, and the power feeding structure is connected to each section.   The light emitting diode device according to claim 6, wherein the drive circuit includes a time division switching circuit. The light-emitting diode device according to claim 7, wherein the time-division switching circuit includes two or more time-division switching circuit units.

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