Vehicle interior lighting system

Abstract

To provide a vehicle interior lighting system in which the number of wires connecting plural lamp units to a host ECU that controls the plural lamp units is small and which can also reduce an amount of data in an instruction signal transmitted from the host ECU to the plural lamp units.SOLUTION: A vehicle interior lighting system 1 performs LIN communication and includes: plural lamp units 11 connected by one bus cable 12; and a host ECU 10 that transmits an effect instruction signal S1 for instructing a content of an effect produced by light emission operation of the plural lamp units 11 to the plural lamp units 11 through the bus cable 12. Each of the plural lamp units 11 includes a light-emitting element 112 and a control IC 111 that controls output of the light-emitting element 112 according to the content of the effect instruction signal S1. The effect instruction signal S1 is transmitted once to each of the plural lamp units 11 per effect instruction, regardless of duration of the effect.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an interior lighting system. [Background technology]

[0002] Conventionally, there has been known a lighting unit used in a vehicle, which includes a plurality of lighting loads, a control unit that outputs control signals to independently control these lighting loads, and a wire harness structure that connects the plurality of lighting loads to the control unit (see Patent Document 1).

[0003] In the lighting unit described in Patent Document 1, a chip built into the relay connector of the wire harness structure controls the power supply to each lighting load in accordance with a control signal transmitted from the control unit, thereby reducing the burden on the control unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-133985 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the lighting unit described in Patent Document 1, one signal line is used for each of the lighting loads to connect the relay connector of the wire harness structure to the multiple lighting loads, which makes the lighting unit heavy and large, occupying space when it is installed.

[0006] The object of the present invention is to provide an interior lighting system that requires less wiring to connect multiple lamp units to the host ECU that controls them, and that can reduce the amount of data in the instruction signals sent from the host ECU to the multiple lamp units. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention provides the following interior lighting system.

[0008] [1] An interior lighting system that uses LIN communication or CAN communication, comprising: a plurality of lamp units connected by one or two bus cables; and a host ECU that transmits a performance instruction signal to the plurality of lamp units via the bus cables, which signal instructs the content of the performance to be produced by the light-emitting operation of the plurality of lamp units; each of the plurality of lamp units comprises a light-emitting element and a control IC that controls the output of the light-emitting element according to the content of the performance instruction signal; and the performance instruction signal is transmitted to the plurality of lamp units once for each instruction of a single performance, regardless of the performance time. [2] The in-vehicle lighting system described in [1] above, wherein the upper ECU combines only the necessary instruction information from among the multiple instruction information and includes it in the performance instruction signal each time the performance instruction signal is transmitted. [3] An interior lighting system as described in [1] or [2] above, wherein when the performance instruction signal contains instruction information specifying an operation to simultaneously change the output of the plurality of lamp units, the control IC synchronizes the timing at which it changes the output of the light-emitting elements in the plurality of lamp units. [4] The interior lighting system according to [1] or [2] above, wherein each of the plurality of lamp units includes a plurality of the light-emitting elements. [5] An interior lighting system that performs LIN communication, wherein the number of nodes of the plurality of lamp units is 15 or more, as described in [1] or [2] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an interior lighting system that requires less wiring to connect multiple lamp units to a host ECU that controls them, and that can reduce the amount of data in the instruction signals sent from the host ECU to the multiple lamp units. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of an interior lighting system according to an embodiment of the present invention. [Figure 2] Fig. 2(a) is a diagram conceptually showing the timing of signal transmission from a host ECU to a lamp unit while a performance is being performed in a conventional lighting system using LIN communication. Fig. 2(b) is a diagram conceptually showing the timing of signal transmission from a host ECU to a lamp unit while a performance is being performed in an in-vehicle lighting system according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing an example of the performance instruction information included in the performance instruction signal S1. [Figure 4] Fig. 4(a) is a side view of a light guide to which two or more lamp units are connected via a single bus cable, and Fig. 4(b) is an external view of the light guide to which the lamp units that supply light to the light guide and the housing that houses the light guide are attached. [Figure 5] 5(a) to 5(c) are schematic diagrams for comparing the number of wires between a conventional lighting unit as a comparative example and an in-vehicle lighting system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Interior lighting system configuration) Fig. 1 is a block diagram showing a schematic configuration of an interior lighting system 1 according to an embodiment of the present invention, in which the power supply and GND are not shown.

[0012] The interior lighting system 1 includes a plurality of lamp units 11 connected by a single bus cable 12, and a host ECU (Electronic Control Unit) 10 that transmits performance instruction signals to the plurality of lamp units 11 via the bus cable 12.

[0013] The vehicle interior lighting system 1 is an interior lighting system that performs LIN (Local Interconnect Network) communication, and is capable of controlling a plurality of lamp units 11 connected by a single bus cable 12 with a single host ECU 10.

[0014] 1, the number of lamp unit 11 nodes (the number of lamp units connected by one bus cable) is 15, and 15 lamp units 11 (11a to 11o) are included in the interior lighting system 1. The LIN communication standard recommends that the maximum number of slave devices connected to one master device be 15, due to its communication capacity.

[0015] Each lamp unit 11 includes a light emitting element 112 such as an LED as a light source, and a control IC 111 such as a microcomputer (microcontroller) that controls the output of the light emitting element 112 according to the content of the received performance instruction signal.

[0016] Each lamp unit 11 may include a plurality of light-emitting elements 112. Typically, each lamp unit 11 includes a light-emitting element 112 that emits red light, a light-emitting element 112 that emits green light, and a light-emitting element 112 that emits blue light.

[0017] The effect instruction signal is a signal for instructing the content of the effect (hereinafter, sometimes simply referred to as effect) produced by the light emitted by the multiple lamp units 11 included in the interior lighting system 1. The effect may be, for example, the multiple lamp units 11 fading in to light up or fading out to light down all at once, turning on or off in order from one end, or repeating turning on and off randomly for a predetermined period of time.

[0018] The performance instruction signal includes performance instruction information for instructing the performance of the plurality of lamp units 11. The performance instruction information is configured by a combination of a plurality of pieces of instruction information such as position information, brightness information, color information, and operation information.

[0019] The position information is information that specifies which of the plurality of lamp units 11 is to be controlled, and the control IC 111 of the specified lamp unit 11 operates the light emitting element 112 .

[0020] The brightness information is information that specifies the light emission intensity of the lamp unit 11, and the control IC 111 of the lamp unit 11 changes the output of the light emitting element 112 based on the brightness information.

[0021] The color information is information that specifies the light emission color of the lamp unit 11, and the control IC 111 of the lamp unit 11 changes the output of each of the plurality of light emitting elements 112 that emit light of different colors based on the color information.

[0022] The operation information is information that specifies the overall movement of the multiple lamp units 11, for example, whether the brightness of the multiple lamp units 11 should change simultaneously, sequentially, or randomly, and the control IC 111 of each lamp unit 11 controls the timing at which the light-emitting element 112 operates based on the operation information.

[0023] In each lamp unit 11, the control IC 111 derives a time schedule for power supply to the light-emitting elements 112 to realize the performance instruction based on the performance instruction information included in the performance instruction signal transmitted from the host ECU 10. Then, the control IC 111 controls the output of the light-emitting elements 112 by changing the amount of power supply to the light-emitting elements 112 according to the derived time schedule.

[0024] A vehicle control device including an ECU or the like may be connected to the host ECU 10, which is capable of notifying the host ECU 10 of the vehicle state. In this case, when the vehicle control device notifies the host ECU 10 of, for example, the start of the vehicle drive device or the unlocking of the vehicle, the host ECU 10 transmits performance instruction signals to the plurality of lamp units 11 according to the content of the notification.

[0025] The host ECU 10 may also be connected to an operation unit that receives operations by a vehicle occupant to instruct the multiple lamp units 11 to perform effects. In this case, for example, when an operation by the occupant on the operation unit is notified to the host ECU 10, the host ECU 10 transmits an effect instruction signal to the multiple lamp units 11 according to the content of the instructed effect.

[0026] Fig. 2(a) is a diagram conceptually showing the timing of signal transmission from the host ECU 50 to the lamp unit 51 while a performance is being performed in a conventional lighting system 5 that performs LIN communication. Fig. 2(b) is a diagram conceptually showing the timing of signal transmission from the host ECU 10 to the lamp unit 11 while a performance is being performed in an in-vehicle lighting system 1 according to an embodiment of the present invention.

[0027] 2(a) indicates that the control IC 511 controls the output of the light-emitting element 512. Similarly, the arrows connecting the control IC 111 and the light-emitting element 112 in FIG. 2(b) indicates that the control IC 111 controls the output of the light-emitting element 112.

[0028] In the conventional lighting system 5, the host ECU 50 transmits a signal S5 including output information specifying the output of the light-emitting element 512 (if the lamp unit 51 includes multiple light-emitting elements 512, output information for each of the multiple light-emitting elements 512) to the lamp unit 51. Upon receiving the signal S5, the control IC 511 of the lamp unit 51 controls the output of the light-emitting element 512 in accordance with the output information for the light-emitting element 512 included in the signal S5.

[0029] When a performance is performed by causing a plurality of lamp units 51 to emit light, the host ECU 50 continues to repeatedly send the signal S5 to the plurality of lamp units 51 until the performance is completed. Therefore, the longer the performance time, the more times the signal S5 is sent, and the larger the amount of communication required for the performance.

[0030] For example, to perform an effect in which all lamp units 51 are turned on and faded in over X seconds, the host ECU 50 repeatedly transmits a signal S5, which specifies gradually increasing output, to all lamp units 51 for X seconds.

[0031] On the other hand, in the in-vehicle lighting system 1 according to the embodiment of the present invention, the host ECU 10 sends a performance instruction signal S1 to the lamp unit 11, and the control IC 111 of the lamp unit 11 controls the output of the light-emitting element 112 in accordance with the information on the performance content contained in the performance instruction signal S1.

[0032] According to the interior lighting system 1, the performance instruction signal S1 does not instruct the output of the light-emitting elements 112 like the above-mentioned signal S5, but rather instructs the content of the performance. Therefore, in instructing one performance, the performance instruction signal S1 is transmitted only once to each of the multiple lamp units 11, regardless of the performance time of that performance, and the specific operation of the light-emitting elements 112 is controlled by the control IC 111 that receives the performance instruction signal S1.

[0033] Furthermore, since the performance instruction signal S1 is transmitted only once to each of the lamp units 11 in one performance instruction, the communication volume of the performance instruction signal S1 transmitted in one performance is constant regardless of the performance time.

[0034] For example, to perform an effect in which all lamp units 11 are made to light up in a fade-in manner over X seconds, the host ECU 50 transmits a performance instruction signal S1 to all lamp units 11 once, the performance instruction signal S1 including performance instruction information such as position information specifying all lamp units 11 as control targets and brightness information instructing that the brightness be increased to brightness Y over X seconds. The control ICs 111 of all lamp units 11 that receive the performance instruction signal S1 derive a time schedule for supplying power to the light-emitting elements 111 in order to increase the brightness of the lamp units 11 to brightness Y over X seconds, and control the output of the light-emitting elements 111 for X seconds.

[0035] As an example, the following shows the approximate results of calculations of communication volume and the like in the conventional lighting system 5 and the in-vehicle lighting system 1 when fading in 15 lamp units over a period of 3 seconds. In this specific example, the communication volume per communication is 8 bytes, and each communication takes 10 ms.

[0036] In the conventional lighting system 5, if it is possible to transmit signals S5 for two lamp units 51 in one communication, then it is possible to transmit signals S5 to all 15 lamp units 51 in eight communications. Therefore, the communication volume and time required to transmit the signal S5 once to all lamp units 51 are 64 bytes (8 bytes x 8 times) and 80 ms (10 ms x 8 times), respectively.

[0037] If one cycle is defined as sending signal S5 to all lamp units 51 once, then the number of cycles in the three seconds until the fade-in lighting effect ends is 38 (3000 ms ÷ 80 ms), and the total communication volume in the three seconds is 2432 bytes (64 bytes × 38 times).

[0038] On the other hand, in the interior lighting system 1, if it is possible to transmit the performance instruction signal S1 for one lamp unit 11 in one communication, it is possible to transmit the performance instruction signal S1 to all 15 lamp units 11 in 15 communications. Therefore, the communication volume and time required to transmit the performance instruction signal S1 once to all lamp units 11 are 120 bytes (8 bytes × 15 times) and 150 ms (10 ms × 15 times), respectively.

[0039] Since the performance instruction signal S1 is sent only once per performance, the number of cycles in the three seconds until the fade-in lighting performance ends is one (the light-emitting operation of the lamp unit 11 for three seconds is controlled by the control IC 111 that receives the performance instruction signal S1), and the total communication volume for three seconds is 120 bytes (120 bytes x 1 time).

[0040] As described above, in the conventional lighting system 5, the longer the duration of the performance, the larger the amount of communication traffic becomes, and therefore, a large amount of data needs to be stored in the host ECU 50, which is the source of the communication. As a result, it is not possible to perform long-lasting or detailed performances.

[0041] In contrast, the interior lighting system 1 can reduce the amount of communication from the host ECU to the lamp units compared to the conventional lighting system 5, allowing for longer and more detailed lighting effects. For example, in the fade-in lighting effect exemplified above, it is possible to make the brightness change smoother or to make the lamps brighter over a longer period of time. Therefore, for example, by fading in the lighting of multiple lamp units 11 in order from the edge, it is possible to create a flowing lighting action.

[0042] Furthermore, the greater the number of nodes in the lamp unit, the greater the difference in communication volume between the conventional lighting system 5 and the in-vehicle lighting system 1. For this reason, when the number of nodes in the lamp unit 11 is 15 or more, which is the maximum number generally recommended for LIN communication, the difference in communication volume with the conventional lighting system becomes particularly large.

[0043] In the interior lighting system 1, the combination of performance instruction information included in the performance instruction signal S1 can be changed each time the performance instruction signal S1 is transmitted. As described above, the performance instruction information included in the performance instruction signal S1 is made up of a combination of multiple pieces of instruction information such as position information, brightness information, color information, and operation information, but each time the performance instruction signal S1 is transmitted, only the necessary information out of these pieces of instruction information can be combined and included in the performance instruction signal S1, thereby reducing the amount of communication traffic.

[0044] 3 is a schematic diagram showing an example of the performance instruction information included in the performance instruction signal S1. The performance instruction signal S1 marked with "1st" in FIG. 3 conceptually indicates the first transmission, the performance instruction signal S1 marked with "2nd" indicates the second transmission, and the performance instruction signal S1 marked with "3rd" indicates the third transmission.

[0045] In the example shown in FIG. 3, first, the host ECU 10 transmits a performance instruction signal S1 including position information, brightness information, color information, and operation information as performance instruction information to the plurality of lamp units 11 to instruct the first performance.

[0046] If the only difference between the content of the first and second performances is the position of the operating lamp unit 11 and the brightness of the lamp unit 11, a performance instruction signal S1 containing only position information and brightness information as performance instruction information is transmitted to instruct the second performance. In other words, color information and operation information specifying the same color and operation of the lamp unit 11 as in the first performance are not included in the performance instruction signal S1 as performance instruction information.

[0047] When the difference between the contents of the second and third performances is only the light emission color of the lamp unit 11, a performance instruction signal S1 including only color information as performance instruction information is transmitted to instruct the third performance.

[0048] The vehicle interior lighting system 1 is superior to the conventional lighting system 5 that performs LIN communication in that the outputs of the plurality of lamp units 11 can be changed simultaneously.

[0049] In LIN communication, a command signal is sent from a host ECU to multiple lamp units in sequence, so in a conventional lighting system 5 in which the host ECU 50 sends a signal S5 containing output information specifying the output of the light-emitting element 512 to multiple lamp units 51, when the signal S5 that changes the output of multiple lamp units 51 is sent, there is a slight difference in the timing of changing the output between the multiple lamp units 51.

[0050] Meanwhile, in the interior lighting system 1, by transmitting to the plurality of lamp units 11 a performance instruction signal S1 including, as performance instruction information, instruction information (one of the above-mentioned operation information) that specifies an operation to simultaneously change the output of the plurality of lamp units 11, it is possible to synchronize the timing at which the control ICs 111 of the plurality of lamp units 11 change the output of the light-emitting elements 112 of the plurality of lamp units 11. This allows the plurality of lamp units 11 to simultaneously turn on and off, change brightness, etc.

[0051] The interior lighting system 1 may have a configuration in which one host ECU 10 controls a group of lamp units (a group made up of a plurality of lamp units 11 connected by one bus cable 12).

[0052] The interior lighting system 1 may also be used as part of another network such as a CAN (Controller Area Network) network. In this case, for example, a gateway that converts between CAN communication and LIN communication corresponds to the upper ECU 10.

[0053] (Example of lamp unit placement) The lamp units 11 are used as light sources for, for example, cowl illumination, foot illumination, door illumination, and luggage illumination. Lamp units 11 arranged at different positions inside the vehicle may be connected to one another by a single bus cable 12. Also, for example, two or more of the lamp units 11 connected to a single bus cable 12 in the interior lighting system 1 may be connected to the same light guide.

[0054] FIG. 4(a) is an external view of a light guide 2 to which two or more lamp units 11, each of which is connected by a single bus cable 12, are connected. The light guide 2 includes a rod-shaped first light guide 21 having a prism surface 211 along its length where prisms 212 are provided for reflecting light propagating inside and emitting it to the outside, and a rod-shaped second light guide 22 formed integrally with the rod-shaped first light guide 21. The first light guide 21 and the second light guide 22 have light intake portions 213 and 221 at their ends, respectively, for taking in light from the lamp unit 11. The prisms 212 are, for example, composed of a group of linear grooves or protrusions arranged on the prism surface 211 and each extending in a direction perpendicular to the longitudinal direction of the first light guide 21.

[0055] 4(b) is an external view showing a state in which a lamp unit 11 that supplies light to the light guide 2 and a housing 3 that houses the light guide 2 are attached to the light guide 2. The lamp unit 11 supplies light to the light intake portions 213 and 221 of the light guide 2. For example, the light guide 2 and the lamp unit 11 are each fixed to the housing 3, and the light guide 2, the lamp unit 11, and the housing 3 form an illumination device that is used in vehicle interiors such as an instrument panel.

[0056] Light emitted from the lamp unit 11 enters the first light guide section 21 from the light intake section 213 or the light intake section 221 of the second light guide section 22, is reflected by the prism 212, and is emitted to the outside from the surface of the first light guide section 21 opposite the prism surface 211.

[0057] (Variation) In the above embodiment, the vehicle interior lighting system 1 has been described as a system that performs LIN communication, but the vehicle interior lighting system 1 may also be a system that performs CAN communication. That is, even if the vehicle interior lighting system 1 is a system that performs CAN communication, the above configuration makes it possible to control the operations of the plurality of lamp units 11 by a performance instruction signal that is transmitted from the host ECU 10 to each of the plurality of lamp units 11 only once for one performance.

[0058] A system that performs CAN communication differs from a system that performs LIN communication in that it uses two bus cables 12 for communication between a host ECU 10 and multiple lamp units 11 and in the communication speed (CAN communication is 1000 kbps, LIN communication is 19.2 kbps).

[0059] Even when the interior lighting system 1 is a system that uses CAN communication, compared to conventional lighting units such as the lighting unit described in Patent Document 1, in which each light source included in a lamp unit is connected to a host ECU by an independent signal line, the number of wires connecting multiple lamp units to the host ECU that controls them can be reduced, and the amount of data in the instruction signals sent from the host ECU to the multiple lamp units can be reduced.

[0060] 5(a) to 5(c) are schematic diagrams for comparing the number of wires of a conventional lighting unit 6 as a comparative example and an in-vehicle lighting system 1 according to an embodiment of the present invention. In Fig. 5(a) to 5(c), the number of nodes of the lamp unit is set to 3 as an example.

[0061] 5(a) has an R light source that emits red light, a G light source that emits green light, and a B light source that emits blue light in each lamp unit 61, and each of these three light sources is connected to a host ECU 60 via a signal line 62 for sending a control signal that adjusts the brightness of the light source. In addition, the three lamp units 61 are commonly connected to one power supply line 63 and one GND line 64.

[0062] In the lighting unit 6, one signal line 62 is used for each of the three light sources included in the lamp unit 61. Therefore, if the number of nodes of the lamp units 61 included in the lighting unit 6 is n, the total number of wires connecting the upper ECU 60 and the n lamp units 61 is 3n+2 (3n signal lines 62, one power line 63, and one GND line 64).

[0063] 5(b) shows an interior lighting system 1 that performs LIN communication. As described above, in the interior lighting system 1 that performs LIN communication, multiple lamp units 11 are connected by one bus cable 12. Therefore, in the interior lighting system 1 that performs LIN communication, the total number of wires connecting the upper ECU 10 and the multiple lamp units 11 is three (one bus cable 12, one power supply line 13, and one GND line 14), regardless of the number of nodes of the lamp units 11.

[0064] 5(c) shows an interior lighting system 1 that performs CAN communication. In the interior lighting system 1 that performs CAN communication, multiple lamp units 11 are connected by two bus cables 12. Therefore, in the interior lighting system 1 that performs CAN communication, the total number of wires connecting the upper ECU 10 and the multiple lamp units 11 is four (two bus cables 12, one power supply line 13, and one GND line 14), regardless of the number of nodes of the lamp units 11.

[0065] As shown in Figures 5(a) to (c), the interior lighting system 1 according to the embodiment of the present invention has fewer wires than the lighting unit 6, regardless of whether LIN communication or CAN communication is used, and this difference in the number of wires becomes more pronounced as the number of nodes in the lamp unit increases.

[0066] Furthermore, in the interior lighting system 1 that performs CAN communication, similar to the interior lighting system 1 that performs LIN communication, the performance instruction signal S1 is transmitted only once to each of the lamp units 11 in order to instruct one performance, so the communication volume of the performance instruction signal S1 transmitted in one performance is constant regardless of the performance time. Therefore, it is possible to reduce the data volume of the instruction signal transmitted from the host ECU 10 to the lamp units 11. In the interior lighting system 1 that performs CAN communication, the performance instruction signal S1 is transmitted through two bus cables 12.

[0067] In addition, the interior lighting system 1 that performs CAN communication has similar features to those of the interior lighting system 1 that performs LIN communication described above, such as being able to combine only the necessary information from these instruction information and include it in the performance instruction signal S1 each time it transmits the signal, and being able to synchronize the timing at which the control ICs 111 of the multiple lamp units 11 change the output of the light-emitting elements 112 of the multiple lamp units 11.

[0068] (Effects of the embodiment) The interior lighting system 1 according to the embodiment of the present invention described above is a system that performs LIN communication in which multiple lamp units 11 are connected by one bus cable 12, or a system that performs CAN communication in which multiple lamp units 11 are connected by two bus cables 12, and can control the operation of the multiple lamp units 11 by a performance instruction signal that is sent from the upper ECU 10 to each of the multiple lamp units 11 only once per performance.

[0069] In other words, according to an embodiment of the present invention, it is possible to provide an interior lighting system that requires less wiring to connect multiple lamp units to a host ECU that controls them, and that can reduce the amount of data in the instruction signals sent from the host ECU to the multiple lamp units.

[0070] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications can be made without departing from the spirit of the invention. Furthermore, the components of the above embodiments can be combined in any manner without departing from the spirit of the invention. Furthermore, the above embodiments do not limit the invention according to the claims. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. [Explanation of symbols]

[0071] 1. Interior lighting system 10 Upper ECU 11 Lamp unit 111 Control IC 112 Light-emitting element 12 Bus Cable

Claims

1. An interior lighting system that performs LIN communication or CAN communication, a plurality of lamp units connected by one or two bus cables; a host ECU that transmits a performance instruction signal to the plurality of lamp units via the bus cable, the performance instruction signal instructing the content of the performance to be performed by the light emitting operations of the plurality of lamp units; Equipped with Each of the plurality of lamp units includes a light-emitting element and a control IC that controls an output of the light-emitting element in accordance with the content of the performance instruction signal, The performance instruction signal is transmitted to each of the plurality of lamp units once for each instruction of a single performance, regardless of the performance time. Interior lighting system.

2. the host ECU, each time transmitting the performance instruction signal, combines only necessary instruction information from the plurality of pieces of instruction information and includes it in the performance instruction signal; The interior lighting system according to claim 1 .

3. When the performance instruction signal includes instruction information that specifies an operation of simultaneously changing the outputs of the plurality of lamp units, the control IC synchronizes the timing at which the output of the light-emitting element is changed in the plurality of lamp units.

3. The vehicle interior lighting system according to claim 1 or 2.

4. Each of the plurality of lamp units includes a plurality of the light-emitting elements.

3. The vehicle interior lighting system according to claim 1 or 2.

5. An interior lighting system that performs LIN communication, The number of nodes of the plurality of lamp units is 15 or more.

3. The vehicle interior lighting system according to claim 1 or 2.

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