Interior lighting system

Abstract

To provide an in-car illumination system that controls a plurality of devices connected by one bus cable, by one illumination ECU and can smoothly increase or decrease the brightness of a lamp unit.SOLUTION: An in-car illumination system 1 is provided in which transmission of operation instruction signals by an illumination ECU 12 transmitting operation instruction signals including equal-lightness information one by one to a plurality of lamp units 11 in order is regarded as one set. When gradually increasing or decreasing the lightness of the plurality of lamp units 11, N sets (N is an arbitrary integer equal to or larger than 2) of operation instruction signals are successively transmitted, so that lightness of each of the plurality of lamp units 11 continuously increases or decreases from when an nth set (n is an arbitrary plus integer with N-1 being a maximum value) of operation instruction signal is received until when an (n+1)th set of operation instruction signal is received.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, an interior lighting system has been known that includes multiple interior lights, an illumination module that drives them, and a body ECU that sends interior light control commands to the illumination module, with each of the multiple interior lights independently connected to the illumination module (see Patent Document 1).

[0003] According to the interior lighting system described in Patent Document 1, the interior lights can be faded in or out by repeatedly transmitting the interior light control command while changing the brightness (duty of the PWM signal) contained in the interior light control command.

[0004] Further, conventionally, there is known an interior lighting system in which a plurality of lighting elements are connected to an ambient lighting module that controls the lighting elements via a LIN (Local Interconnect Network) (see Patent Document 2).

[0005] In LIN, multiple devices connected by a single bus cable are controlled by a single control unit. This means that the number of cables used in the system can be reduced compared to when using communication standards in which multiple devices are each connected to the control unit by independent cables, resulting in benefits such as weight reduction, space savings, and cost reduction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-203215 [Patent Document 2] US Patent Application Publication No. 2015 / 0321603 Summary of the Invention [Problem to be solved by the invention]

[0007] However, LIN has a slow communication speed, and because signals are sent sequentially to multiple devices connected to a single bus cable, the more devices connected to a single bus cable, the longer the intervals between each device receiving the signal when signals are sent continuously.

[0008] For this reason, in an interior lighting system that uses LIN as a communication standard, such as the interior lighting system described in Patent Document 2, when the brightness of the lamp unit is gradually increased (fade in) or gradually decreased (fade out), the intervals at which signals instructing different brightness levels reach the lamp unit become longer, giving the impression that the brightness is changing in stages, which could result in a poor appearance.

[0009] The object of the present invention is to provide an interior lighting system in which a single illumination ECU controls multiple devices connected by a single bus cable, and which can smoothly increase or decrease the brightness of the lamp units. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the present invention provides the following interior lighting system.

[0011] [1] An interior lighting system comprising: a plurality of lamp units connected by a single bus cable; and an illumination ECU that transmits operation instruction signals to the plurality of lamp units via the bus cable, wherein one set of transmission of the operation instruction signals by the illumination ECU is defined as transmitting the operation instruction signals containing the same brightness information to the plurality of lamp units one by one in sequence; when gradually increasing or decreasing the brightness of the plurality of lamp units, N sets of operation instruction signals (N is any integer equal to or greater than 2) are transmitted consecutively; and the brightness of each of the plurality of lamp units continuously increases or decreases from the time the nth set (n is any positive integer with N-1 as the maximum value) of the operation instruction signals is received until the time the n+1th set of operation instruction signals is received. [2] The in-vehicle lighting system according to [1] above, wherein the n-th set of operation instruction signals includes information on the brightness to be reached when the n+1-th set of operation instruction signals is received, and information on continuously changing the brightness. [3] The interior lighting system described in [2] above, wherein each of the plurality of lamp units calculates a rate of increase or decrease in brightness from when the nth set of operation instruction signals are received to when the n+1th set of operation instruction signals are received, based on information on the brightness that should be reached when the n+1th set of operation instruction signals are received and the interval from when the nth set of operation instruction signals are received to when the n+1th set of operation instruction signals are received. [4] The interior lighting system described in [2] above, wherein each of the plurality of lamp units refers to a table in which the relationship between the brightness of the plurality of lamp units and the manner in which the brightness of the plurality of lamp units increases or decreases is recorded, and determines, from the information on the brightness of the plurality of lamp units contained in the operation instruction signal received in the nth set, how to increase or decrease the brightness from the time the nth set of operation instruction signals is received to the time the n+1th set of operation instruction signals is received. [5] The vehicle interior lighting system according to any one of [1] to [4] above, wherein the operation instruction signal is transmitted to the plurality of lamp units by LIN communication via the bus cable. [6] The interior lighting system according to [5] above, wherein the plurality of lamp units includes 15 or more lamp units. [7] An interior lighting system as described in any one of [1] to [4] above, comprising a plurality of lamp unit groups each consisting of a plurality of lamp units connected by the single bus cable, and the illumination ECU transmits the operation instruction signal to the plurality of lamp unit groups. [8] The vehicle interior lighting system according to any one of the above [1] to [4], wherein two or more of the plurality of lamp units are connected to the same light guide. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an interior lighting system in which a single illumination ECU controls multiple devices connected by a single bus cable, and which can smoothly increase or decrease the brightness of the lamp unit. [Brief explanation of the drawings]

[0013] [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 is a graph showing a schematic diagram of the change in brightness of a specific lamp unit when the brightness of multiple lamp units is gradually increased in a manner similar to that of a conventional general vehicle interior lighting system using LIN communication. [Figure 3] FIG. 3 is a graph showing a schematic diagram of changes in brightness of a predetermined lamp unit when the brightness of a plurality of lamp units is gradually increased by the interior lighting system according to the embodiment of the present invention. [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 a diagram showing a state in which the lamp units that supply light to the light guide and the housing that houses the light guide are attached to the light guide. DETAILED DESCRIPTION OF THE INVENTION

[0014] (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.

[0015] The interior lighting system 1 includes a plurality of lamp units 11 connected by a single bus cable 14, and an illumination ECU 12 that transmits operation instruction signals to the plurality of lamp units 11 via the bus cable 14. The operation instruction signals include information on brightness (the brightness at which the lamp units 11 are lit), and the lamp units 11 that receive the operation instruction signals turn on or off at a brightness based on the brightness information included in the operation instruction signals. The brightness information included in the operation instruction signals is, for example, information that specifies the output of a light-emitting element used as a light source for the lamp units 11.

[0016] The interior lighting system 1 uses communication standards such as LIN (Local Interconnect Network) and CXPI (Clock Extension Peripheral Interface), which allow multiple lamp units 11 connected by a single bus cable 14 to be controlled by a single illumination ECU 12.

[0017] The operation instruction signal transmitted from the illumination ECU 12 is transmitted to the plurality of lamp units 11 by LIN communication (communication based on the LIN communication standard) or CXPI communication (communication based on the CXPI communication standard) via the bus cable 14. The following describes an example in which LIN communication is used to transmit the operation instruction signal to the plurality of lamp units 11 via the bus cable 14.

[0018] 1, LIN communication is used in combination with CAN (Controller Area Network) communication in the interior lighting system 1. In this case, a gateway 13 that converts between LIN communication and CAN communication is used between the lamp unit group 10 (10a, 10b) and the illumination ECU 12.

[0019] Here, the lamp unit group 10 is a group made up of a plurality of lamp units 11 connected by a single bus cable 14. Due to communication capacity limitations, the LIN communication standard limits the maximum number of slave devices that can be connected to one master device to 16. Therefore, in one lamp unit group 10, a maximum of 16 lamp units 11 can be connected by a single bus cable 14.

[0020] LIN communication is performed between the gateway 13 and the multiple lamp units 11 included in the lamp unit group 10 via a bus cable 14, and CAN communication is performed between the illumination ECU 12 and the gateway 13 via a cable 15. Note that communication based on another communication standard, such as CXPI communication, may be performed between the illumination ECU 12 and the gateway 13 instead of CAN communication.

[0021] 1, two lamp unit groups 10a and 10b are included in the interior lighting system 1, but there is no particular limitation on the number of lamp unit groups 10 included in the interior lighting system 1. When multiple lamp unit groups 10 are included in the interior lighting system 1, the illumination ECU 12 transmits operation instruction signals to the multiple lamp unit groups 10. In this case, as exemplified in FIG. 1, one gateway 13 may be used in common for the multiple lamp unit groups 10, or one gateway 13 may be used for each of the multiple lamp unit groups 10.

[0022] Furthermore, the LIN communication may be used alone without being combined with the CAN communication or the like in the interior lighting system 1. In this case, the LIN communication is performed between the illumination ECU 12 and the plurality of lamp units 11.

[0023] The lamp unit 11 includes, for example, a light emitting element such as an LED as a light source, and a control unit such as a microcomputer (microcontroller) that causes the light emitting element to emit light in response to an operation instruction signal received from the illumination ECU 12.

[0024] The illumination ECU 12 may be connected to an operation unit that receives user operations to control the operation of the lamp units 11. In this case, for example, when the illumination ECU 12 is notified of a user operation on the operation unit, the illumination ECU 12 transmits operation instruction signals to the plurality of lamp units 11 according to the content of the operation, such as turning on, turning off, or changing the brightness.

[0025] Furthermore, an ECU that can notify the illumination ECU 12 of the vehicle state may be connected to the illumination ECU 12. In this case, when the ECU notifies the illumination ECU 12 of, for example, the start of the vehicle drive device or the unlocking of the vehicle, the illumination ECU 12 transmits operation instruction signals to the plurality of lamp units 11 according to the content of the notification.

[0026] (Interior lighting system operation) FIG. 2 is a graph showing a schematic diagram of the change in brightness of a specific lamp unit 11 when the brightness of multiple lamp units 11 is gradually increased in a manner similar to that of a conventional general vehicle interior lighting system using LIN communication.

[0027] According to the LIN communication standard, when transmitting an operation instruction signal, the illumination ECU 12 transmits operation instruction signals containing the same brightness information one by one in sequence to all of the lamp units 11 connected by one bus cable 14. When gradually increasing (fading in) or gradually decreasing (fading out) the brightness of the lamp units 11, the illumination ECU 12 transmits multiple sets of operation instruction signals consecutively, with one set consisting of operation instruction signals containing the same brightness information being transmitted one by one in sequence to all of the lamp units 11 connected by one bus cable 14.

[0028] t in Figure 2 n indicates the timing at which a predetermined lamp unit 11 receives the nth set of operation instruction signals (n is any positive integer). n+1 -t n is equal to the time it takes for all of the lamp units 11 connected by one bus cable 14 to receive the operation instruction signals transmitted in sequence, i.e., one set of operation instruction signals. Therefore, the greater the number of lamp units 11 connected by one bus cable 14, the shorter the interval t n+1 -t n becomes larger.

[0029] And the interval t n+1 -t n For example, when 15 lamp units 11 are connected to one bus cable 14, the interval t n+1 -t n The interval t is about 80 ms. n+1 -t n If the time is 80 ms or more, the gradual change in brightness is easily noticeable to the user.

[0030] 2 is a graph showing an example of gradually increasing the brightness of the lamp unit 11, so the brightness increases as n increases. Conversely, when gradually decreasing the brightness of the lamp unit 11, the brightness decreases as n increases. In this case as well, the interval t n+1 -tn The larger the value, the less smooth the change in brightness will appear, and the more gradual it will appear.

[0031] 3 is a graph showing a schematic diagram of the change in brightness of a given lamp unit 11 when the brightness of the plurality of lamp units 11 is gradually increased by the interior lighting system 1 according to the embodiment of the present invention. The dotted line in FIG. 3 shows the change in brightness by the conventional general interior lighting system shown in FIG. 2 as a comparative example.

[0032] In the interior lighting system 1 according to the embodiment of the present invention, in accordance with the LIN communication standard, when transmitting an operation instruction signal, the illumination ECU 12 transmits operation instruction signals containing the same brightness information one by one in sequence to all of the lamp units 11 connected by one bus cable 14. When gradually increasing or decreasing the brightness of the lamp units 11, the illumination ECU 12 transmits multiple sets of operation instruction signals consecutively, with one set consisting of operation instruction signals containing the same brightness information being transmitted one by one in sequence to all of the lamp units 11 connected by one bus cable 14.

[0033] On the other hand, in the vehicle interior lighting system 1 according to the embodiment of the present invention, t n When the nth set of operation instruction signals received at t receives the n+1th set of operation instruction signals, n+1 The information includes information on the brightness that should be reached and information on how to change the brightness continuously. Note that the information on how to change the brightness continuously indicates, for example, whether or not to change the brightness continuously, and because the amount of data is extremely small, it places little strain on LIN communication, which has a small communication capacity.

[0034] When the operation instruction signal includes information to continuously change the brightness, when each of the lamp units 11 receives the operation instruction signal of the (n+1)th set, t n+1 When the brightness information to be reached and the nth set of operation instruction signal are received, n When the n+1th set of operation instruction signals is received from tn+1 Interval t n+1 -t n When the nth set of operation instruction signals is received based on n When the n+1th set of operation instruction signals is received from t n+1 Calculate the rate of increase or decrease in brightness up to the

[0035] Here, when the brightness of the plurality of lamp units 11 is gradually increased as shown in FIG. n From t n+1 In the case where the brightness of the lamp units 11 is gradually decreased, the increase rate of the brightness is calculated as t n From t n+1 The brightness decrease rate is calculated from the t n From t n+1 The slope up to t n From t n+1 Equal to the rate of increase in brightness up to

[0036] Each of the lamp units 11 n From t n+1 Based on the rate of increase or decrease in brightness up to t n From t n+1 The brightness is continuously increased or decreased until t n From t n+1 The calculation of the rate of increase or decrease up to and the control of brightness based on the calculation are performed by, for example, a microcomputer included in the lamp unit 11.

[0037] That is, when gradually increasing or decreasing the brightness of the multiple lamp units 11, N sets (N is any integer equal to or greater than 2) of operation instruction signals are transmitted consecutively, and the brightness of each of the multiple lamp units 11 increases or decreases consecutively from when the nth set (n is any positive integer with N-1 as the maximum value) of operation instruction signals is received until when the n+1th set of operation instruction signals is received.

[0038] As a result, t n and t n+1The brightness of the lamp unit 11 between these values ​​is linearly interpolated, and the change in brightness of the lamp unit 11 is not gradual but smooth, like a curve, as shown in Fig. 2. Note that the change in brightness when the lamp unit 11 gradually decreases its brightness will be, for example, a shape that is the left-right reverse of the change in brightness in Fig. 2.

[0039] Furthermore, the lamp unit 11 refers to a table in which the relationship between the brightness of the lamp unit 11 and how the brightness of the lamp unit 11 increases or decreases is recorded, and n and t n+1 The brightness of the lamp unit 11 may be supplemented between the above.

[0040] For example, when the operation instruction signal contains information to continuously change the brightness, each of the plurality of lamp units 11 refers to the table and determines the brightness of the plurality of lamp units 11 when the nth set of operation instruction signals are received from the information on the brightness of the plurality of lamp units 11 contained in the nth set of operation instruction signals. n When the n+1th set of operation instruction signals is received from t n+1 Determines how the brightness increases or decreases from

[0041] In this case, t n From t n+1 The brightness can be increased or decreased in multiple steps or can be changed in a curved line, so that the brightness of the lamp unit 11 can be changed more smoothly. The above table is stored in a semiconductor memory included in the lamp unit 11, for example, and the microcomputer included in the lamp unit 11 refers to this table to set the brightness. n From t n+1 It is possible to determine how the brightness increases or decreases from

[0042] As mentioned above, the interval t n+1 -t nWhen the delay time is 80 ms or more, the gradual change in brightness is easily noticeable to the user. Therefore, when 15 or more lamp units 11 are connected to one bus cable 14, the effect of smoothing the change in brightness of the lamp units 11 according to the embodiment of the present invention is more pronounced.

[0043] It should be noted that when the brightness of the lamp unit 11 is gradually increased or decreased, the brightness at the start and end of the change does not need to be the minimum value (off) or the maximum value.

[0044] For example, the timing at which the lamp unit 11 receives an instruction to gradually increase the brightness may be when the lamp unit 11 is in an off state or when the lamp unit 11 is in an on state. Furthermore, when the lamp unit 11 receives an instruction to gradually increase the brightness, the brightness may be increased to the maximum brightness or to a brightness other than the maximum brightness.

[0045] Similarly, the timing at which lamp unit 11 receives the instruction to gradually decrease the brightness may be when it is lit at maximum brightness or when it is lit at a brightness other than maximum brightness. Furthermore, when lamp unit 11 receives the instruction to gradually decrease the brightness, it may decrease the brightness until it is turned off, or may decrease the brightness to a level that does not turn it off.

[0046] (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 14. Also, for example, two or more of the lamp units 11 connected to a single bus cable 14 in the interior lighting system 1 may be connected to the same light guide.

[0047] FIG. 4(a) is a side view of the light guide 2 to which two or more lamp units 11, each of which is connected by a single bus cable 14, 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 the light 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.

[0048] 4(b) is a diagram 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.

[0049] 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.

[0050] (Effects of the embodiment) The interior lighting system 1 using LIN communication uses fewer cables, which results in weight reduction, space saving, and cost reduction, but on the other hand, there is a problem that the change in brightness is not smooth but perceived as stepwise, depending on the number of lamp units 11 connected by one bus cable 14. According to the interior lighting system 1 according to the embodiment of the present invention described above, even when using LIN communication, it is possible to smoothly change the brightness of the lamp units 11.

[0051] Furthermore, similar effects can be obtained when CXPI communication, which has similar characteristics to LIN communication, is used. When LIN communication is used, the interior lighting system 1 can be constructed at lower cost than when CXPI communication is used. However, since LIN communication has a lower communication speed than CXPI communication, the problem of the brightness of the lamp unit 11 changing gradually can easily occur. Therefore, when LIN communication is used, the effect of smoothing the change in brightness of the lamp unit 11 according to the embodiment of the present invention is more pronounced.

[0052] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications can be made without departing from the spirit and scope of the invention. Furthermore, the components of the above-described embodiments can be combined in any manner without departing from the spirit and scope of the invention.

[0053] Furthermore, the above-described embodiments do not limit the scope of the invention as claimed, and 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]

[0054] 1. Interior lighting system 10 Lamp unit group 11 Lamp unit 12 Illumination ECU 13 Gateway 14 Bus Cable 2 Light guide

Claims

1. A plurality of lamp units connected by a single bus cable; an illumination ECU that transmits operation instruction signals to the plurality of lamp units via the bus cable; Equipped with a transmission of the operation instruction signal by the illumination ECU to the plurality of lamp units one by one in sequence, the transmission of the operation instruction signal including the same brightness information being one set; When gradually increasing or decreasing the brightness of the plurality of lamp units, N sets (N is any integer equal to or greater than 2) of the operation instruction signals are transmitted consecutively, and the brightness of each of the plurality of lamp units increases or decreases consecutively from when the nth set (n is any positive integer with N-1 being the maximum value) of the operation instruction signals is received until when the n+1th set of the operation instruction signals is received. Interior lighting system.

2. the n-th set of operation instruction signals includes information on brightness that should be reached when the n+1-th set of operation instruction signals is received, and information on continuously changing brightness; The interior lighting system according to claim 1 .

3. calculates a rate of increase or decrease in brightness from when the nth set of operation instruction signals are received to when the n+1th set of operation instruction signals are received, based on information on brightness that each of the plurality of lamp units should reach when receiving the n+1th set of operation instruction signals and the interval from when the nth set of operation instruction signals are received to when the n+1th set of operation instruction signals are received; 3. The vehicle interior lighting system according to claim 2.

4. each of the plurality of lamp units refers to a table in which the relationship between the brightness of the plurality of lamp units and the manner in which the brightness of the plurality of lamp units is increased or decreased is recorded, and determines, from the information on the brightness of the plurality of lamp units included in the operation instruction signal received at the nth set, how to increase or decrease the brightness from the time when the nth set of operation instruction signals is received to the time when the n+1th set of operation instruction signals is received; 3. The vehicle interior lighting system according to claim 2.

5. the operation instruction signal is transmitted to the plurality of lamp units by LIN communication via the bus cable; The vehicle interior lighting system according to any one of claims 1 to 4.

6. the plurality of lamp units includes 15 or more lamp units; 6. The vehicle interior lighting system according to claim 5.

7. a plurality of lamp unit groups each made up of the plurality of lamp units connected by the single bus cable; the illumination ECU transmits the operation instruction signal to the plurality of lamp unit groups; The vehicle interior lighting system according to any one of claims 1 to 4.

8. Two or more of the plurality of lamp units are connected to the same light guide. The vehicle interior lighting system according to any one of claims 1 to 4.

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