Illumination device and illumination system

Abstract

In the present invention, an illumination device comprises a light source, a light source drive circuit, a first control unit, a non-volatile second storage unit, and a first communication unit. The light source drive circuit supplies power to the light source. The control unit includes a non-volatile first storage unit that stores a control program stipulating a control operation relating to control of the light source, and a first processing circuit that executes the control program to control the light source drive circuit. The first communication unit communicates with an external device. The first control unit receives an update program for the control program through the first communication unit from the external device, stores the received update program in the second storage unit, and rewrites the control program stored in the first storage unit according to the update program stored in the second storage unit.

Description

Lighting device and lighting system CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Japanese Patent Application No. 2022-112156 (filed July 13, 2022), the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to lighting devices and lighting systems.

[0003] 2. Description of the Related Art Illumination devices that irradiate illumination spaces with illumination light have been proposed (see, for example, Patent Documents 1 and 2).

[0004] Japanese Patent Application Laid-Open No. 3-43903 Japanese Patent Application Laid-Open No. 2008-112213

[0005] A lighting device is disclosed.

[0006] In one embodiment, the lighting device includes a light source, a light source drive circuit, a first control unit, a non-volatile second storage unit, and a first communication unit. The light source drive circuit supplies power to the light source. The first control unit includes a non-volatile first storage unit that stores a control program that defines control operations related to control of the light source, and a first processing circuit that executes the control program to control the light source drive circuit. The first communication unit communicates with an external device. The first control unit receives an update program for the control program from the external device via the first communication unit, stores the received update program in the second storage unit, and rewrites the control program stored in the first storage unit with the update program stored in the second storage unit.

[0007] 1 is a block diagram schematically showing an example of the electrical configuration of a lighting system according to a first embodiment. FIG. 1 is a diagram schematically showing an example of the configuration of a lighting system according to a first embodiment. FIG. 2 is a diagram showing an example of the operation of a first processing circuit defined by a control program and a startup program. FIG. 3 is a flowchart showing an example of an update operation of the lighting system. FIG. 4 is a diagram schematically showing the states of a first internal storage unit and an external storage unit during operation of the lighting system. FIG. 5 is a flowchart showing an example of the operation of the lighting system according to a second embodiment. FIG. 6 is a block diagram schematically showing an example of the electrical configuration of a lighting system according to a third embodiment. FIG. 7 is a diagram schematically showing a first operation example of the lighting system according to the third embodiment. FIG. 8 is a diagram schematically showing a second operation example of the lighting system according to the third embodiment. FIG. 9 is a diagram schematically showing a third operation example of the lighting system according to the third embodiment. FIG. 10 is a block diagram schematically showing another example of the electrical configuration of a lighting system according to the third embodiment. FIG. 11 is a block diagram schematically showing an example of the configuration of a lighting device of a lighting system according to a fourth embodiment. FIG. 12 is a diagram showing an example of a timing chart of a lighting device. FIG. 13 is a diagram showing an example of the operation of a lighting system according to a fifth embodiment. FIG. 14 is a block diagram showing an example of the electrical configuration of an external device of a lighting system according to a sixth embodiment. FIG. 15 is a flowchart showing an example of operation related to abnormality processing of the lighting system.

[0008] The inventor has created a technology that enables a lighting system 1 according to a first embodiment to a sixth embodiment to be updated more reliably with less effort.

[0009] <1. First Embodiment> <1-1. Configuration of Lighting System 1> Fig. 1 is a block diagram schematically showing an example of the electrical configuration of a lighting system 1 according to a first embodiment. Fig. 2 is a diagram schematically showing an example of the configuration of the lighting system 1. As shown in Fig. 1, the lighting system 1 includes one or more lighting devices 2 and an external device 7. As shown in Figs. 1 and 2, the lighting system 1 may include a plurality of lighting devices 2. The lighting devices 2 and the external device 7 are capable of communicating with each other.

[0010] Each lighting device 2 is a device that emits illumination light L1 into an illumination space H1. The illumination space H1 may be, for example, a room in a predetermined building or a passageway connecting rooms. As shown in Fig. 2, each lighting device 2 may be installed in an installation space H2 above the ceiling of the illumination space H1. In the example of Fig. 2, each lighting device 2 emits illumination light L1 from the ceiling into the illumination space H1.

[0011] As shown in FIG. 1, each lighting device 2 includes a light source 3, a light source drive circuit 30, a first communication unit 4, a first control unit 5, and an external memory unit 6 (corresponding to a second memory unit).

[0012] The light source 3 emits illumination light L1. The illumination light L1 is, for example, visible light, and may be white light. The light source 3 may include, for example, a light-emitting diode (LED), a semiconductor laser element such as a laser diode (LD), a vertical cavity surface emitting laser (VCSEL), or a super luminescent diode (SLD).

[0013] The light source 3 may further include a wavelength conversion member that emits fluorescence. In this structure, the light-emitting element of the light source 3 emits excitation light to the wavelength conversion member. The excitation light may be light having a peak in a wavelength range from 380 nm to 415 nm, for example. As a specific example, the excitation light may be purple light having a peak near 405 nm. Note that the excitation light is not necessarily limited to purple light, and may be, for example, blue light having a peak near 450 nm. The excitation light does not necessarily have to be emitted into the illumination space H1.

[0014] The wavelength conversion member includes a phosphor and emits fluorescence as illumination light L1 based on the incident excitation light. The fluorescence has a spectrum different from that of the excitation light. Specifically, the peak wavelength of the fluorescence is longer than that of the excitation light, and the fluorescence is visible light. The wavelength conversion member is made of a wavelength conversion material that converts the excitation light into blue light, such as BaMgAl １０ O １７ :Eu or (Sr, Ca, Ba) １０ (P.O. ４ ) ６ Cl２ :Eu, (Sr, Ba) １０ (P.O. ４ ) ６ Cl ２ The wavelength converting member may contain, for example, (Sr, Ba, Ca) as a wavelength converting material that converts the excitation light into blue-green light. ５ (P.O. ４ ) ３ Cl:Eu,Sr ４ Al １４ O ２５ The wavelength converting member may contain, for example, SrSi as a wavelength converting material that converts the excitation light into green light. ２ (O, Cl) ２ N ２ :Eu, (Sr, Ba, Mg) ２ SiO ４ :Eu ２＋ , or ZnS: Cu, Al, Zn ２ SiO ４ The wavelength converting member may contain, for example, Y:Mn as a wavelength converting material that converts the excitation light into red light. ２ O ２ S: Eu, Y ２ O ３ :Eu, SrCaClAlSiN ３ :Eu ２＋ , CaAlSiN ３ : Eu or CaAlSi(ON) ３ The wavelength conversion member may contain 3Ga as a wavelength conversion material that converts the excitation light into light having a wavelength in the near-infrared region. ５ O １２ :Cr, etc. If the wavelength conversion member contains multiple types of wavelength conversion materials corresponding to multiple colors of light, the wavelength conversion member can emit fluorescence with high color rendering. Specifically, if the excitation light is light having a peak in the range of 380 nm to 415 nm and the wavelength conversion member contains phosphors corresponding to red, green, and blue light, the color rendering of the fluorescence can be particularly improved.

[0015] The light source drive circuit 30 is electrically connected to the light source 3 and supplies power to the light source 3 (more specifically, the light-emitting elements of the light source 3). The light source 3 emits illumination light L1 at an intensity corresponding to the power supplied from the light source drive circuit 30. The light source drive circuit 30 is also electrically connected to the first control unit 5 and is controlled by the first control unit 5. Specifically, the first control unit 5 outputs a control signal to the light source drive circuit 30, and the light source drive circuit 30 operates based on the control signal. The control signal may include, for example, a signal for switching between emitting and stopping the illumination light L1 from the light source 3.

[0016] The light source driving circuit 30 may supply controllable power to the light source 3. That is, the light source driving circuit 30 may have a dimming mechanism for the illumination light L1. In the example of FIG. 1 , the light source driving circuit 30 includes a dimming circuit 31 and a dimming driving circuit 32. The dimming circuit 31 may be a power supply circuit including a switching element such as a transistor. For example, if the light source 3 includes a current-driven light-emitting element such as an LED, a constant current circuit may be used as the dimming circuit 31. The dimming circuit 31 is electrically connected to the light source 3 and outputs a controllable current to the light source 3. The light source 3 emits the illumination light L1 with an intensity corresponding to the value of the current. In this way, the intensity of the illumination light L1 from the light source 3 can be adjusted by adjusting the value of the current output by the dimming circuit 31. The dimming circuit 31 may operate using, for example, a pulse-width modulation (PWM) method. Note that the dimming circuit 31 may also be referred to as a light intensity control circuit. The light source 3 may also include a voltage-driven light-emitting element. In this structure, for example, a constant voltage circuit can be applied as the dimming circuit 31, and the dimming circuit 31 outputs a controllable voltage to the light source 3. Below, a structure in which a current-driven type is applied will be described as an example.

[0017] The dimming drive circuit 32 is a circuit for driving the dimming circuit 31 and is electrically connected to the dimming circuit 31. The dimming drive circuit 32 is also electrically connected to the first control unit 5 and receives a control signal for the light source 3 from the first control unit 5. The control signal may include, for example, a data signal D1 indicating a target value for the light intensity of the illumination light L1. The dimming drive circuit 32 generates a drive signal DS in response to the data signal D1 and outputs the drive signal DS to the dimming circuit 31. As a more specific example, the dimming drive circuit 32 outputs the drive signal DS to a control terminal of a switching element of the dimming circuit 31. The switching element switches on and off based on the drive signal DS. The drive signal DS has a pulse train, and the dimming circuit 31 outputs power to the light source 3 according to a duty ratio, which is the ratio of the on time to one cycle of the pulse train. The dimming drive circuit 32 adjusts the duty ratio of the drive signal DS in accordance with the data signal D1 (i.e., the target value of the light intensity), thereby enabling the switching element of the dimming circuit 31 to be switched on and off based on the duty ratio of the drive signal DS (i.e., the target value of the light intensity). As a result, a current corresponding to the target value of the light source flows through the light source 3, and the light source 3 can emit the illumination light L1 with a light intensity corresponding to the target value. The dimming drive circuit 32 may also be called a light intensity driver.

[0018] The dimming drive circuit 32 may generate the drive signal DS based on, for example, a comparison between a target light intensity value and a triangular wave. The triangular wave may be generated by, for example, a timer circuit (not shown) included in the dimming drive circuit 32. Note that the function of generating the drive signal DS of the dimming drive circuit 32 does not necessarily have to be realized by a circuit separate from the first control unit 5, and may be realized by the first control unit 5. In other words, the first control unit 5 may have the function of the dimming drive circuit 32. In this structure, the first control unit 5 outputs the drive signal DS to the dimming circuit 31.

[0019] The first control unit 5 is an electronic circuit and includes, for example, a first processing circuit 51, a first internal storage unit 52 (corresponding to the first storage unit), and a second internal storage unit 53. The first processing circuit 51 may be, for example, a processing circuit such as a central processing unit (CPU). The first internal storage unit 52 is, for example, a non-volatile storage unit such as a read-only memory (ROM). A control program P1 and a startup program P2 are stored in the first internal storage unit 52. The second internal storage unit 53 is, for example, a volatile storage unit such as a random access memory (RAM). The second internal storage unit 53 can function as a working memory for the first processing circuit 51. The first processing circuit 51, the first internal storage unit 52, and the second internal storage unit 53 are electrically connected to each other by wiring such as a bus.

[0020] FIG. 3 is a diagram showing an example of the operation of the first processing circuit 51 defined by the control program P1 and the startup program P2. The control program P1 is, for example, firmware. As shown in FIG. 3, the control program P1 defines a control operation M11 to be performed by the first processing circuit 51 regarding the control of the light source 3. The first processing circuit 51 can read the control program P1 from the first internal storage unit 52 and execute the control program P1 while using the second internal storage unit 53 as a working memory. The first processing circuit 51 operates in accordance with the control operation M11 of the control program P1, causing the first control unit 5 to control the light source 3.

[0021] As shown in FIG. 3 , the startup program P2 defines a rewrite operation M21 by the first processing circuit 51 for rewriting the control program P1. As described in detail below, the rewrite operation M21 is an operation for rewriting the control program P1 with an update program P3 stored in the external storage unit 6. The update program P3 may be, for example, a new version of the control program P1. The first processing circuit 51 reads the startup program P2 from the first internal storage unit 52 and executes it while using the second internal storage unit 53 as a working memory. By operating in accordance with the rewrite operation M21 of the startup program P2, the first control unit 5 rewrites the control program P1 in the first internal storage unit 52 with the update program P3. This allows the control program P1 in the first internal storage unit 52 to be updated to, for example, the latest version.

[0022] The first processing circuit 51, the first internal storage unit 52, and the second internal storage unit 53 may be implemented within a single chip. Such a first control unit 5 may also be referred to as an embedded processor. The number of bits of the first processing circuit 51 may be, for example, approximately 16 bits or less, specifically, 8 bits. The number of bits of such a first processing circuit 51 may be, for example, smaller than the number of bits of a second control unit 72 (described below) of the external device 7. The operating frequency of the first processing circuit 51 may be, for example, approximately 100 MHz or less, specifically, 16 MHz. The operating frequency of such a first processing circuit 51 may be, for example, lower than the operating frequency of the second control unit 72 of the external device 7. The storage capacities of the first internal storage unit 52 and the second internal storage unit 53 may be, for example, 100 kbytes or less, specifically, 32 kbytes. The storage capacities of such a first internal storage unit 52 and the second internal storage unit 53 may be, for example, smaller than the storage capacity of a storage unit (described below) of the second control unit 72.

[0023] The first communication unit 4 is a communication circuit and can transmit and receive signals to and from the external device 7 via wired or wireless communication. The first communication unit 4 includes, for example, a communication integrated circuit (IC). The first communication unit 4 may also be referred to as a communication interface. The communication standard of the first communication unit 4 is not particularly limited, but may be, for example, Ethernet. The first communication unit 4 is electrically connected to the first control unit 5. The first communication unit 4 receives a transmission signal from the first control unit 5 and performs various processes on the transmission signal in accordance with the communication standard. The first communication unit 4 transmits the processed transmission signal to the external device 7, for example, via a communication line LN. Meanwhile, the first communication unit 4 receives a reception signal from the external device 7 via the communication line LN and performs various signal processes on the reception signal in accordance with the communication standard. The first communication unit 4 outputs the processed reception signal to the first control unit 5. Through this operation, communication is performed between the lighting device 2 and the external device 7.

[0024] 3, the control program P1 may also define a communication operation M12 with the external device 7 through the first communication unit 4. This allows the first control unit 5 to send and receive signals to and from the first communication unit 4 while the control program P1 is being executed.

[0025] As shown in Fig. 1, a lighting system 1 in which a plurality of lighting devices 2 are installed may be provided with a concentrator 8. The concentrator 8 is, for example, a network hub, and is located on a communication line LN. The concentrator 8 is electrically connected to each of the plurality of lighting devices 2 and an external device 7 via the communication line LN. In the example of Fig. 2, the concentrator 8 is installed in the installation space H2 together with the lighting devices 2.

[0026] The external storage unit 6 is a non-volatile storage unit, such as a memory. As will be described later, the external storage unit 6 stores an update program P3 for the control program P1 received from the external device 7. The external storage unit 6 is electrically connected to the first control unit 5.

[0027] 2, the light source driving circuit 30, the first communication unit 4, the first control unit 5, and the external storage unit 6 may be mounted on a printed wiring board PB. Alternatively, the light source 3, the light source driving circuit 30, the first communication unit 4, the first control unit 5, the external storage unit 6, and the printed wiring board PB may be housed in a housing 20 of the lighting device 2. In the example of FIG. 2, the lighting device 2 is installed in an installation space H2 above the ceiling, so that a worker needs to climb into the installation space H2 above the ceiling to perform work on the lighting device 2 directly, which is time-consuming.

[0028] The external device 7 may be, for example, a personal computer. The external device 7 is capable of communicating with a plurality of lighting devices 2 and transmitting and receiving various signals. For example, the external device 7 can transmit an update program P3 to the lighting devices 2, as described below.

[0029] The external device 7 may be installed in a space separate from the installation space H2. The external device 7 may be installed within the lighting space H1, or may be installed in an indoor space of a building separate from the lighting space H1.

[0030] As shown in FIG. 1 , the external device 7 may include a second communication unit 71 , a second control unit 72 , a storage unit 73 (corresponding to a third storage unit), and an input unit 74 .

[0031] The second control unit 72 controls the operation of the external device 7. The second control unit 72 is an electronic circuit and includes, for example, a second processing circuit such as a central processing unit, a non-volatile storage unit such as a ROM, and a volatile storage unit such as a RAM, which are electrically connected to each other by wiring such as a bus. A program that defines the operation of the external device 7 is stored in the non-volatile storage unit. The volatile storage unit can function as a working memory for the second processing circuit.

[0032] Second controller 72 may also be referred to as control circuitry and includes at least one processor to provide control and processing power for performing various functions, as described in more detail below.

[0033] According to various embodiments, the at least one processor may be implemented as a single integrated circuit (IC) or as multiple communicatively connected integrated circuits ICs and / or discrete circuits. The at least one processor may be implemented according to various known techniques.

[0034] In one embodiment, a processor includes one or more circuits or units configured to perform one or more data computational procedures or processes, for example, by executing instructions stored in associated memory. In other embodiments, a processor may be firmware (e.g., discrete logic components) configured to perform one or more data computational procedures or processes.

[0035] According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application specific integrated circuits (ASICs), digital signal processors, programmable logic devices, field programmable gate arrays, or any combination of these devices or configurations, or other known combinations of devices and configurations, to perform the functions described below.

[0036] Although the first control unit 5 is an embedded computer as an example, it may have the same or similar configuration as the second control unit 72 .

[0037] The second communication unit 71 is a communication circuit and can transmit and receive signals to and from the first communication unit 4 of the lighting device 2 via a wired or wireless connection. The second communication unit 71 may be a communication IC. The second communication unit 71 may also be called a communication interface. The communication standard of the second communication unit 71 is the same as the communication standard of the first communication unit 4. The second communication unit 71 is electrically connected to the second control unit 72. The second communication unit 71 receives a transmission signal from the second control unit 72 and performs various processes on the transmission signal in accordance with the communication standard. The second communication unit 71 transmits the processed transmission signal to the lighting device 2, for example, via the communication line LN. Meanwhile, the second communication unit 71 receives a reception signal from the lighting device 2 via the communication line LN and performs various signal processes on the reception signal in accordance with the communication standard. The second communication unit 71 outputs the processed reception signal to the second control unit 72. Through this operation, communication is performed between the lighting device 2 and the external device 7.

[0038] The storage unit 73 is, for example, a non-volatile storage unit, such as a memory. The storage unit 73 may be built into the second control unit 72 or may be installed externally to the second control unit 72. The storage unit 73 may store, for example, an update program P3 for the control program P1. This update program P3 is stored in the storage unit 73 by, for example, a user. For example, the update program P3 may be transferred from a portable storage medium to the storage unit 73, or may be downloaded from an external server to the external device 7. The storage unit 73 is electrically connected to the second control unit 72.

[0039] The input unit 74 can accept input from a user. The input unit 74 may also be called a user interface. The input unit 74 may include at least one of a keyboard and a mouse. The input unit 74 is electrically connected to the second control unit 72 and outputs an input signal corresponding to the input from the user to the second control unit 72. The second control unit 72 controls the external device 7 in accordance with the input signal.

[0040] For example, the input unit 74 may receive input regarding the illumination state of the light source 3 of each lighting device 2. The illumination state of the light source 3 includes an on / off state indicating whether the light source 3 is on or off (i.e., lit or unlit). That is, the input unit 74 may receive a user input for switching the light source 3 on or off. The illumination state of the light source 3 may also include the light intensity of the light source 3. That is, the input unit 74 may receive a user input for specifying the light intensity of the illumination light L1 of the lighting device 2. The second control unit 72 may generate an instruction signal for the lighting device 2 based on the input signal from the input unit 74, and transmit the instruction signal to the lighting device 2 via the second communication unit 71. It can also be said that the instruction signal is a signal indicating the illumination state of the light source 3.

[0041] The first control unit 5 of the lighting device 2 receives the instruction signal through the first communication unit 4. The first control unit 5 outputs a control signal to the light-source drive circuit 30 based on the instruction signal. For example, if the instruction signal includes a signal for switching the light source 3 on and off, the first control unit 5 outputs a control signal for switching between supplying and cutting off power to the light source 3 to the light-source drive circuit 30. If the instruction signal is a signal specifying the light intensity of the illumination light L1, the first control unit 5 outputs a control signal (i.e., a data signal D1) indicating a target value for the light intensity to the light-source drive circuit 30.

[0042] As described above, the external device 7 can function as an operation unit for the user to operate the lighting device 2 .

[0043] As shown in FIGS. 1 and 2 , the lighting system 1 may further include a wall switch 75. The wall switch 75 may be located, for example, on a wall of the lighting space H1 in which the lighting device 2 is installed. The wall switch 75 may include, for example, a switch for switching the light source 3 on and off, and may further include a switch for specifying the light intensity of the illumination light L1. As shown in FIG. 1 , the wall switch 75 may be electrically connected to an external device 7. The wall switch 75 outputs signals indicating the states of these switches to the external device 7. The second control unit 72 of the external device 7 may generate an instruction signal for the lighting device 2 based on the signal from the wall switch 75 and transmit the instruction signal to the lighting device 2 via the second communication unit 71.

[0044] In this way, the wall switch 75 functions as an operation unit that allows the user to operate the lighting device 2. For this reason, the lighting system 1 illustrated in Fig. 1 is provided with two operation units, namely, the input unit 74 and the wall switch 75. The wall switch 75 is a type of input unit.

[0045] <1-2. Update Operation of Lighting System 1> Next, an update operation of the lighting system 1 for updating the control program P1 will be described. Fig. 4 is a flowchart showing an example of the update operation of the lighting system 1. Fig. 5 is a diagram schematically showing the states of the first internal storage unit 52 and the external storage unit 6 while the lighting system 1 is operating.

[0046] As shown in the first schematic diagram of Fig. 5, the external storage unit 6 may not initially store the update program P3. First, in step S1, the first processing circuit 51 starts executing the control program P1. In the example of Fig. 5, the hatching on the control program P1 indicates that the control program P1 is currently being executed. Because the control program P1 defines a communication operation M12, execution of the control program P1 establishes communication between the lighting device 2 and the external device 7.

[0047] Next, in step S2, the lighting device 2 receives the update program P3 from the external device 7. As a more specific example, the second control unit 72 of the external device 7 transmits the update program P3 to the lighting device 2 via the second communication unit 71 in response to the establishment of a predetermined update condition. The predetermined update condition is not particularly limited, and may be, for example, a user input of an update instruction to the input unit 74. In other words, when the user inputs an update instruction to the input unit 74, the input unit 74 outputs an input signal corresponding to the user input to the second control unit 72, and the second control unit 72, in response to the input of the input signal, reads the update program P3 from the storage unit 73 and transmits the update program P3 to the lighting device 2 via the second communication unit 71.

[0048] If the lighting system 1 includes a plurality of lighting devices 2, the external device 7 may broadcast the update program P3 to the plurality of lighting devices 2. The first control unit 5 of each lighting device 2 receives the update program P3 from the external device 7 via the first communication unit 4.

[0049] Next, in step S3, the first control unit 5 determines whether the update program P3 was received successfully. If the update program P3 was not received successfully, in step S30, for example, the first control unit 5 determines whether the number of retransmissions is equal to or greater than a specified number n. The number of retransmissions refers to the number of times the update program P3 has been transmitted. If the number of retransmissions is still less than the specified number n, in step S31, the first control unit 5 increments the number of retransmissions by 1 and executes step S2 again. As a more specific example of operation, the first control unit 5 may transmit a request signal requesting retransmission of the update program P3 to the external device 7 via the second communication unit 71. The request signal may include, for example, communication identification information for the external device 7 and communication identification information for the lighting device 2 that transmitted the request signal. This identification information may be, for example, an address such as an IP (Internet Protocol) address and a MAC (Media Access Control) address. When the second control unit 72 of the external device 7 receives the request signal via the second communication unit 71, it checks the identification information included in the request signal. Based on the identification signal, the second control unit 72 can recognize that the request signal is addressed to itself, and in response to the request signal, the second control unit 72 retransmits the update program P3 via the second communication unit 71 to the lighting device 2 having the identification signal included in the request signal.

[0050] On the other hand, if the number of retransmissions is equal to or greater than the specified number n in step S30, the first control unit 5 may terminate the update operation. In other words, if the update program P3 cannot be received normally even after retrying to receive the update program P3 the specified number n, the first control unit 5 terminates the update operation.

[0051] If it is determined in step S3 that the update program P3 has been received correctly, then in step S4, the first control unit 5 stores the update program P3 in the external storage unit 6. The first control unit 5 may also determine whether the update program P3 has been successfully stored in the external storage unit 6. This storage check determination may be performed, for example, by comparing the received update program P3 with the update program P3 read from the external storage unit 6. If the update program P3 has not been successfully stored in the external storage unit 6, the first control unit 5 may retry storing the update program P3 up to a predetermined number of times. If the update program P3 has not been successfully stored in the external storage unit 6 even after retrying the predetermined number of times, the first control unit 5 may terminate the update operation.

[0052] The second schematic diagram in FIG. 5 shows a state in which the update program P3 has been successfully stored in the external storage unit 6 in step S4.

[0053] In steps S2 to S4, S30, and S31, the first control unit 5 operates in accordance with the control program P1. That is, the control program P1 in the above example also defines a download operation M13 for receiving the update program P3 from the external device 7 and storing the update program P3 in the external storage unit 6 (see also FIG. 3). The control program P1 also defines a check operation M14 for checking reception and storage.

[0054] Next, in step S5, the first control unit 5 stops the control program P1 and starts the execution of the startup program P2. That is, the control program P1 also defines a call operation M15 for stopping the control program P1 and executing the startup program P2 (see also FIG. 3). In the third schematic diagram of FIG. 5, the fact that the startup program P2 is running is indicated by the hatching on the startup program P2.

[0055] Next, in step S6, the first control unit 5 reads the update program P3 from the external storage unit 6 and rewrites the control program P1 stored in the first internal storage unit 52 with the update program P3. If the update program P3 is a new version of the control program P1 itself, the first control unit 5 overwrites the control program P1 with the update program P3. This updates the control program P1 to the latest version. The fourth schematic diagram in FIG. 5 schematically shows a state in which the control program P1 is being rewritten, and the fifth schematic diagram in FIG. 5 schematically shows a state in which the rewriting of the control program P1 has been completed.

[0056] Next, in step S7, the first processing circuit 51 stops the startup program P2 and executes the control program P1 in the first internal storage unit 52. This enables the first control unit 5 to control the lighting device 2 in accordance with the latest control program P1. Note that if the rewriting of the control program P1 has been successfully completed, the first control unit 5 may delete the update program P3 from the external storage unit 6.

[0057] In steps S6 and S7, the first control unit 5 operates in accordance with the startup program P2. That is, the startup program P2 defines a rewrite operation M21 for rewriting the control program P1 using the update program P3 (see FIG. 3). The startup program P2 also defines a call operation M22 for stopping the startup program P2 and executing the control program P1.

[0058] <1-3. Summary of lighting system 1> As described above, according to the lighting system 1, the external device 7 installed in a space separate from the installation space H2 transmits the update program P3 to the lighting device 2 installed in the installation space H2. Therefore, there is no need for a worker to climb into the installation space H2 to input the update program P3 into the lighting device 2, and the effort required for the update work can be reduced.

[0059] Furthermore, the first control unit 5 stores the update program P3 in the non-volatile external storage unit 6 in step S4, and then rewrites the control program P1 in the first internal storage unit 52 with the update program P3 in the external storage unit 6 in step S6. Therefore, even if the first control unit 5 fails to rewrite the control program P1 due to an abnormality such as a power outage during the rewrite, the update program P3 is not lost. In other words, if the rewrite fails midway, the control program P1 stored in the first internal storage unit 52 may be lost, but the update program P3 stored in the external storage unit 6 is maintained. Therefore, the first control unit 5 can again rewrite the control program P1 in the first internal storage unit 52 with the update program P3 in the external storage unit 6 by executing the startup program P2. This allows the first control unit 5 to more reliably update the control program P1.

[0060] Furthermore, as described above, the first control unit 5 may determine whether the update program P3 has been received successfully, and may execute the startup program P2 if it has been determined that the update program P3 has been received successfully (steps S3 and S5). If the update program P3 has been received successfully, the first control unit 5 can store the update program P3 in the external storage unit 6 with a high probability. Therefore, the first control unit 5 can execute the startup program P2 with the update program P3 more reliably stored in the external storage unit 6. Therefore, the first control unit 5 can more reliably update the control program P1.

[0061] Furthermore, as described above, the first control unit 5 may determine whether the update program P3 has been successfully stored in the external storage unit 6, and may execute the startup program P2 when it has been determined that the update program P3 has been successfully stored. This allows the first control unit 5 to update the control program P1 more reliably.

[0062] Furthermore, as described above, the download operation M13 for receiving and storing the update program P3 may be defined in the control program P1. This eliminates the need for the communication operation M12 to be defined in the startup program P2. Because the communication operation M12 is large in size, the size of the startup program P2 can be reduced compared to when the communication operation M12 is defined in the startup program P2. Conversely, because the control program P1 defines the communication operation M12 for controlling the light source 3, the download operation M13 can be defined in the control program P1 using the communication operation M12, which is unlikely to lead to an increase in the size of the program. This reduces the overall size of the control program P1 and the startup program P2.

[0063] 2. Second Embodiment In the first embodiment, the control program P1 is stopped while the control program P1 is being rewritten, and therefore the first control unit 5 does not perform an operation in accordance with the control operation M11 of the control program P1. Therefore, the light source 3 stops emitting the illumination light L1. To enable the light source 3 to emit the illumination light L1 after the rewriting of the control program P1 is complete, a user input may be required via an operation unit such as the input unit 74 or the wall switch 75. Such user input is time-consuming for the user.

[0064] Therefore, in the second embodiment, after the control program P1 is rewritten, the illumination state of the illumination device 2 before the control program P1 was rewritten is automatically reproduced. The illumination state here includes an off-off state indicating whether the light source 3 is on or off, and the light intensity of the illumination light L1.

[0065] The configuration of the lighting system 1 according to the second embodiment is the same as the configuration of the lighting system 1 according to the first embodiment, except that the lighting system 1 stores state information indicating the lighting state of the lighting device 2 immediately before the control program P1 is rewritten, and after the control program P1 is rewritten, the lighting state of the lighting device 2 is set to the stored lighting state.

[0066] 6 is a flowchart showing an example of the operation of the lighting system 1 according to the second embodiment. In the second embodiment, steps S8 and S9 are further executed in addition to the first embodiment.

[0067] 6 , step S8 may be executed between step S4 and step S5. In step S8, the first control unit 5 of the lighting device 2 stores status information indicating the lighting state of the light source 3, for example, in the first internal storage unit 52 or the external storage unit 6. Here, the first control unit 5 stores the status information in the external storage unit 6. That is, after the first control unit 5 successfully stores the update program P3 in the external storage unit 6 (step S4), it stores status information indicating the lighting state of the lighting device 2 at that time in the external storage unit 6 (step S8), and then stops the control program P1 and executes the startup program P2 (step S5).

[0068] Then, in steps S6 and S7, the first control unit 5 rewrites the control program P1 with the update program P3, stops the startup program P2, and executes the control program P1.

[0069] As shown in FIG. 6 , step S9 may be executed after step S7. In step S9, the first control unit 5 reads the status information from the external storage unit 6 and controls the light source drive circuit 30 based on the status information. That is, the first control unit 5 generates a control signal based on the status information and outputs the control signal to the light source drive circuit 30. The light source drive circuit 30 drives the light source 3 based on the control signal. For example, the dimming drive circuit 32 generates a drive signal DS having a duty ratio based on the light intensity included in the status information and outputs the drive signal DS to the dimming circuit 31. The dimming circuit 31 outputs a current to the light source 3 at a current value based on the drive signal DS. This allows the light source 3 to emit the illumination light L1 at the light intensity included in the status information. That is, after the rewriting of the control program P1 is completed, the first control unit 5 controls the light source 3 so that the illumination state of the light source 3 is the illumination state immediately before the rewriting of the control program P1.

[0070] As described above, according to the second embodiment, the illumination state of the light source 3 immediately before the control program P1 is rewritten is automatically reproduced after the control program P1 is rewritten. Therefore, even if the light source 3 stops emitting the illumination light L1 due to the rewriting of the control program P1, after the control program P1 is rewritten, the light source 3 again emits the illumination light L1 at the light intensity immediately before the rewriting. Therefore, the user does not need to operate the operation units such as the input unit 74 and the wall switch 75 again after the control program P1 is rewritten. This improves user convenience.

[0071] In the above example, the first control unit 5 stores the status information in the first built-in storage unit 52 or the external storage unit 6, but the external device 7 may store the status information in the storage unit 73. For example, the second control unit 72 of the external device 7 is electrically connected to an operation unit such as the input unit 74 and the wall switch 75, and is therefore able to recognize the lighting status of the light source 3 of each lighting device 2. Therefore, the second control unit 72 may store status information indicating the lighting status of the light source 3 for each lighting device 2 in the storage unit 73.

[0072] Then, when communication is established between the lighting device 2 and the external device 7 after the control program P1 is updated, the second control unit 72 may transmit the status information stored in the storage unit 73 to each lighting device 2 via the second communication unit 71. The first control unit 5 of each lighting device 2 receives the status information via the first communication unit 4 and outputs a drive signal to the light source drive circuit 30 based on the status information. This allows the light source 3 of each lighting device 2 to emit the illumination light L1 in the lighting status immediately before the control program P1 was rewritten.

[0073] 3. Third Embodiment As described in the first embodiment, the control program P1 is stopped while the control program P1 is being rewritten. Therefore, the emission of the illumination light L1 from the light source 3 is stopped while the control program P1 is being rewritten. Therefore, if the control program P1 is rewritten while a user is in the illumination space H1 while the illumination light L1 is being emitted, the illumination light L1 will suddenly disappear, which is inconvenient for the user.

[0074] Therefore, the third embodiment aims to improve convenience for the user.

[0075] 7 is a block diagram schematically illustrating an example of the electrical configuration of a lighting system 1 according to the third embodiment. The lighting device 2 according to the third embodiment differs from the lighting device 2 according to the first embodiment in the presence or absence of a sensor.

[0076] In the example of FIG. 7 , the lighting system 1 further includes a first sensor 81. The first sensor 81 can detect, for example, a person in the lighting space H1. The first sensor 81 may include, for example, a motion sensor. As a more specific example, the first sensor 81 can be a motion sensor such as an infrared motion sensor, an ultrasonic motion sensor, or an electrostatic motion sensor. Alternatively, a camera can be used as the first sensor 81. The camera captures an image of an imaging area in the lighting space H1 to generate image data. Image processing of this image data can detect a person in the imaging area. As shown in FIG. 7 , the first sensor 81 may be electrically connected to an external device 7. The first sensor 81 outputs an electrical signal indicating the detection result to the external device 7.

[0077] In the third embodiment, the lighting system 1 may rewrite the control program P1 using the update program P3, with one of the update conditions being that the first sensor 81 does not detect a person. In other words, the first control unit 5 of the lighting device 2 may rewrite the control program P1 when the first sensor 81 does not detect a person.

[0078] 8 is a diagram schematically illustrating a first operation example of the lighting system 1 according to the third embodiment. Initially, the first control unit 5 of the lighting device 2 executes the control program P1. In other words, step S1 in the first embodiment has already been executed.

[0079] In the example of FIG. 8 , in step S10, the second control unit 72 of the external device 7 checks the detection result of the first sensor 81. Next, in step S11, the second control unit 72 determines whether an update condition is met based on the detection result of the first sensor 81. One of the update conditions is, for example, that the first sensor 81 does not detect a person. When the first sensor 81 detects a person, the second control unit 72 executes step S10 again. On the other hand, when the first sensor 81 does not detect a person, the second control unit 72 transmits the update program P3 to the lighting device 2 via the second communication unit 71. In other words, in response to the fact that the first sensor 81 does not detect a person, the external device 7 transmits the update program P3 to the lighting device 2. The first control unit 5 of the lighting device 2 receives the update program P3 via the first communication unit 4.

[0080] As another update condition, a user input of an update instruction to the input unit 74 may be applied. That is, when a user input of an update instruction is received and the first sensor 81 does not detect a person, the external device 7 may transmit the update program P3 to the lighting device 2.

[0081] The operations from step S10 to the reception of the update program P3 by the first control unit 5 correspond to step S2 in the first embodiment. The first control unit 5 may execute steps S3, S30, and S31, as in the first embodiment.

[0082] Next, the first control unit 5 executes steps S4 to S7 in the same manner as in the first embodiment. That is, the first control unit 5 rewrites the control program P1 with the update program P3 and executes the rewritten control program P1.

[0083] As described above, according to the third embodiment, the external device 7 transmits the update program P3 when the first sensor 81 does not detect a person. This allows the lighting device 2 to rewrite the control program P1 when there is a high possibility that no person is present in the lighting space H1. In other words, the lighting system 1 prohibits writing of the control program P1 when the first sensor 81 detects a person. This increases the likelihood of avoiding a situation in which the illumination light L1 suddenly disappears while a person is present in the lighting space H1.

[0084] FIG. 9 is a diagram schematically illustrating a second operation example of the lighting system 1 according to the third embodiment. As shown in FIG. 9 , the external device 7 may transmit the update program P3 to the lighting device 2 regardless of the result of determining the update condition using the first sensor 81. For example, when a user inputs an update instruction to the input unit 74, the second control unit 72 may transmit the update program P3 to the lighting device 2 via the second communication unit 71 prior to steps S10 and S11. When the first control unit 5 of the lighting device 2 receives the update program P3 via the first communication unit 4, it stores the update program P3 in the external storage unit 6 in step S4, as in the first embodiment. However, the first control unit 5 does not execute step S5 and does not rewrite the control program P1 unless it receives an update instruction signal from the external device 7.

[0085] The second control unit 72 may execute steps S10 and S11 after transmitting the update program P3. When the second control unit 72 determines that the update condition using the first sensor 81 is met, that is, in response to the first sensor 81 not detecting a person, the second control unit 72 may transmit an update instruction signal to the lighting device 2 through the second communication unit 71. When the first control unit 5 of the lighting device 2 receives the update instruction signal through the first communication unit 4, the first control unit 5 executes steps S5 to S7 to rewrite the control program P1.

[0086] According to this second operation example, the lighting device 2 can also rewrite the control program P1 in response to the satisfaction of the update condition using the first sensor 81, that is, when the first sensor 81 does not detect a person. Moreover, according to the second operation example, the lighting device 2 receives the update program P3 in advance, without waiting for the satisfaction of the update condition, that is, when the first sensor 81 does not detect a person. Therefore, when the update condition is satisfied, it is highly likely that the update program P3 is already stored in the external storage unit 6. Therefore, the lighting device 2 can rewrite the control program P1 more quickly after the update condition is satisfied.

[0087] 7 , the first sensor 81 may be electrically connected to the first control unit 5 of the lighting device 2. With this structure, the first control unit 5 of the lighting device 2 can confirm the detection result of the first sensor 81 without communicating with the external device 7. Therefore, the first control unit 5 of the lighting device 2 may determine whether or not a person is present in the lighting space H1 based on the detection result of the first sensor 81.

[0088] 10 is a diagram schematically illustrating a third operation example of the lighting system 1 according to the third embodiment. As shown in FIG. 10 , when the first control unit 5 of the lighting device 2 receives the update program P3 from the external device 7 via the first communication unit 4, the first control unit 5 stores the update program P3 in the external storage unit 6 in step S4. Next, in step S12, the first control unit 5 checks the detection result of the first sensor 81, and in step S13, determines whether the update condition is met based on the detection result of the first sensor 81. If the first sensor 81 detects a person, step S12 is executed again. On the other hand, if the first sensor 81 does not detect a person, the first control unit 5 executes steps S5 to S7 to rewrite the control program P1.

[0089] According to the third operation example, the lighting device 2 can also rewrite the control program P1 in response to the establishment of the update condition, that is, when the first sensor 81 does not detect a person. Moreover, according to the third operation example, the lighting device 2 determines whether the update condition is met, thereby reducing the processing load on the second control unit 72 of the external device 7.

[0090] In the above example, the detection result of the first sensor 81 is used only to determine the update condition. However, the use of the first sensor 81 is not necessarily limited to this. For example, the lighting system 1 may switch the light source 3 between emitting and stopping the illumination light L1 based on the detection result of the first sensor 81. As a specific example, when the first sensor 81 does not detect a person, the first control unit 5 may turn off the light source 3. With this configuration, the detection result of the first sensor 81 is used both to control the light source 3 and to rewrite the control program P1. In other words, there is no need to separately install a first sensor 81 dedicated to rewriting the control program P1. This eliminates the need to install a new first sensor 81. This reduces the manufacturing cost of the lighting system 1 compared to installing a new first sensor 81.

[0091] <3-1. First Alternative Example of Update Condition> In the above example, the first sensor 81 is a sensor that detects a person in the illumination space H1, and the condition that the first sensor 81 does not detect a person is applied as the update condition using the first sensor 81. However, the update condition is not necessarily limited to this.

[0092] Fig. 11 is a diagram schematically illustrating another example of the configuration of the lighting system 1 according to the third embodiment. As shown in Fig. 11, the lighting system 1 may further include a second sensor 82. The second sensor 82 measures the illuminance of the lighting space H1. The second sensor 82 may be an illuminance sensor. Alternatively, the second sensor 82 may be a camera. The illuminance in the imaging area can be determined by image processing of the image data generated by the camera.

[0093] Like the first sensor 81, the second sensor 82 may be electrically connected to the external device 7, or may be electrically connected to the first control unit 5 of the lighting device 2. The second sensor 82 outputs an electrical signal indicating the measurement result to the second control unit 72 of the external device 7 or the first control unit 5 of the lighting device 2.

[0094] The lighting system 1 may rewrite the control program P1 in response to the establishment of an update condition that the illuminance of the lighting space H1 is equal to or lower than a predetermined illuminance. Conversely, the lighting system 1 may prohibit the rewriting of the control program P1 when the illuminance of the lighting space H1 is higher than the predetermined illuminance. The predetermined illuminance may be set in advance to a value close to zero, for example. The specific update operation of the lighting system 1 is the same as or similar to the description with reference to FIGS. 8 to 10 , except for the update condition. Therefore, a repeated description will be avoided here.

[0095] This allows the control program P1 to be rewritten when the illumination space H1 is dark. When the illumination space H1 is dark, the illumination light L1 is already extinguished, so even if the illumination light L1 is not emitted due to rewriting of the control program P1, there is almost no change in the illumination state of the illumination space H1. This reduces the possibility of a sudden change in the illumination state due to rewriting of the control program P1.

[0096] In the above example, the measurement results of the second sensor 82 are used only to determine the update conditions. However, the use of the second sensor 82 is not necessarily limited to this. For example, the lighting system 1 may adjust the amount of illumination light L1 from the light source 3 based on the measurement results of the second sensor 82. With this configuration, the measurement results of the second sensor 82 are used both to control the light source 3 and to rewrite the control program P1. In other words, there is no need to install a separate second sensor 82 dedicated to rewriting the control program P1. This allows for a reduction in the manufacturing costs of the lighting system 1 compared to installing a new second sensor 82.

[0097] 3-2. Second Alternative Example of Update Condition In the above example, the lighting system 1 includes at least one of the first sensor 81 and the second sensor 82. However, this is not necessarily limited to this. The lighting system 1 may rewrite the control program P1 only during a predetermined specified time period. Conversely, the lighting system 1 may prohibit rewriting of the control program P1 during time periods other than the specified time period. In other words, one of the update conditions may be that the current time is within the specified time period.

[0098] The current time can be measured using, for example, a timer circuit. The timer circuit can also be considered a sensor that measures the current time. The specified time period can be set by, for example, a user.

[0099] When the external device 7 is responsible for determining whether the update condition is met, the timer circuit may be included in, for example, the second control unit 72 of the external device 7. The input unit 74 of the external device 7 may accept input of the specified time period. For example, the user may input to the input unit 74 a time period when no one is present in the illumination space H1 or a time period when the light source 3 of the illumination device 2 is turned off. As a specific example, the user may input a nighttime time period to the input unit 74. The second control unit 72 may store time period information indicating the specified time period input from the input unit 74 in the storage unit 73. The second control unit 72 obtains the current time from the timer circuit and reads the time period information from the storage unit 73. The second control unit 72 determines whether the current time is within the specified time period, and if the current time is within the specified time period, may transmit the update program P3 or even an update instruction signal to the illumination device 2 via the second communication unit 71.

[0100] When the lighting device 2 is responsible for determining whether the update conditions are met, the timer circuit may be included in, for example, the first control unit 5 of the lighting device 2. The second control unit 72 of the external device 7 may transmit time zone information indicating the specified time zone input from the input unit 74 to the lighting device 2 via the second communication unit 71. When the first control unit 5 of the lighting device 2 receives the time zone information via the first communication unit 4, it stores the time zone information in, for example, the external storage unit 6. The first control unit 5 obtains the current time from the timer circuit and reads the time zone information from, for example, the external storage unit 6. The first control unit 5 determines whether the current time is within the specified time zone, and if the current time is within the specified time zone, rewrites the control program P1 with the update program P3.

[0101] This allows the control program P1 to be rewritten when the current time is within a specified time period. Since the specified time period can be specified by the user, the time period for rewriting the control program P1 can be freely set. This improves user convenience. For example, a time period when there is a high possibility that no one will be in the lighting space H1 can be set as the specified time period.

[0102] 4. Fourth Embodiment In the fourth embodiment, it is intended that the light source 3 continues to emit the illumination light L1 even while the control program P1 is being rewritten.

[0103] Fig. 12 is a block diagram schematically illustrating an example of the electrical configuration of the lighting device 2 of the lighting system 1 according to the fourth embodiment. As shown in Fig. 12, the dimming drive circuit 32 includes a data holding unit 321. The data holding unit 321 can hold the data signal D1 input from the first control unit 5 as a held signal D2. The data holding unit 321 may be, for example, a memory or a hardware circuit such as a flip-flop circuit. The dimming drive circuit 32 generates a drive signal DS based on the held signal D2 held in the data holding unit 321 and outputs the drive signal DS to the dimming circuit 31.

[0104] The first control unit 5 outputs a data signal D1, a clock signal CL, and an enable signal EN to the dimming drive circuit 32 in accordance with the control program P1. For example, the output of the data signal D1, the clock signal CL, and the enable signal EN may be specified in a control operation M11 of the control program P1. The data signal D1 is, for example, a signal indicating a target value for the intensity of the illumination light L1. The clock signal CL is a signal for synchronizing the operation of the first control unit 5 with the operation of the dimming drive circuit 32. The enable signal EN is a signal that controls whether or not the hold signal D2 in the data holding unit 321 is updated. Specifically, when the enable signal EN is in a high (H) state, the data holding unit 321 updates the hold signal D2 based on the data signal D1. Therefore, when the enable signal EN is in a high state, the data holding unit 321 holds the most recent input data signal D1 as the hold signal D2 every time the data signal D1 is input from the first control unit 5. Because the hold signal D2 matches the latest data signal D1, the dimming drive circuit 32 generates a drive signal DS based on the latest data signal D1 and outputs the drive signal DS to the dimming circuit 31. The dimming circuit 31 outputs a current to the light source 3 based on the drive signal DS, so that the light source 3 can emit illumination light L1 with a light amount based on the latest data signal D1.

[0105] On the other hand, when the enable signal EN is in a low (L) state, the data holding unit 321 does not update the held signal D2 based on the data signal D1. In other words, when the enable signal EN is in a low state, the data holding unit 321 maintains the held signal D2 regardless of the input data signal D1. Therefore, the data holding unit 321 maintains the held signal D2 immediately before the enable signal EN transitions from a high state to a low state. The dimming drive circuit 32 continues to output a drive signal DS based on this held signal D2 to the dimming circuit 31, and the dimming circuit 31 continues to output a current to the light source 3 based on the drive signal DS. Therefore, the light source 3 continues to emit the illumination light L1 with the same light intensity as immediately before the enable signal EN transitions from a high state to a low state.

[0106] Fig. 13 is a diagram showing an example of a timing chart of the lighting device 2. Fig. 13 shows an example of changes over time in the enable signal EN, the data signal D1, the hold signal D2, and the drive signal DS.

[0107] As shown in FIG. 13 , the first control unit 5 sets the enable signal EN to a high state while the control program P1 is being executed. Therefore, while the first control unit 5 is controlling the light source 3 in accordance with the control program P1, the data holding unit 321 holds the data signal D1 as the hold signal D2. Therefore, the hold signal D2 matches the data signal D1, and the light source 3 emits illumination light L1 at a light intensity corresponding to the data signal D1. For example, in FIG. 13 , the data signal D1 indicates a value D11 before time t1, so the data holding unit 321 holds the value D11 as the hold signal D2. The dimming drive circuit 32 generates a drive signal DS based on the hold signal D2 and outputs the drive signal DS to the dimming circuit 31. The dimming circuit 31 outputs a current to the light source 3 based on the drive signal DS, and the light source 3 emits illumination light L1 at a light intensity corresponding to the value D11.

[0108] Here, at time t1, the user performs an input to change the light intensity, for example, using the wall switch 75. In response to this, the external device 7 transmits an instruction signal to change the light intensity to the lighting device 2, and the first control unit 5 of the lighting device 2 changes the data signal D1 from value D11 to value D12 based on the instruction signal. At time t1, the first control unit 5 is operating in accordance with the control program P1, so the enable signal EN remains high. Therefore, the data holding unit 321 also updates the held signal D2 from value D11 to value D12. Therefore, the light source 3 emits illumination light L1 with a light intensity based on value D12.

[0109] Here, the lighting system 1 starts an update operation at time t2 after time t1. For example, at time t2, a user inputs an update instruction to the input unit 74. In response to the input, the external device 7 transmits an update program P3 to the lighting device 2, and the first control unit 5 of the lighting device 2 stores the update program P3 in the external storage unit 6. After recording the update program P3 in the external storage unit 6, the first control unit 5 may transition the enable signal EN from a high state to a low state.

[0110] At a subsequent time t3, the first control unit 5 stops the control program P1 and starts executing the startup program P2. By stopping the control program P1, the first control unit 5 changes the value of the data signal D1 to zero. In other words, the first control unit 5 stops outputting the data signal D1. The first control unit 5 updates the control program P1 with the update program P3 in accordance with the startup program P2.

[0111] The data holding unit 321 continues to hold, as the held signal D2, the value D12 that was present immediately before the enable signal EN changed from high to low. Therefore, even during execution of the startup program P2 after time t3, the dimming drive circuit 32 continues to output the drive signal DS based on the held signal D2 to the dimming circuit 31. Therefore, the dimming circuit 31 continues to output a current to the light source 3 at the same magnitude as the current value immediately before the control program P1 was stopped (i.e., immediately before time t3), and the light source 3 continues to emit the illumination light L1 at the same light intensity as immediately before the control program P1 was stopped. In other words, the light source 3 continues to emit the illumination light L1 even during the rewriting of the control program P1 using the update program P3.

[0112] As described above, according to the fourth embodiment, the lighting state of the lighting space H1 immediately before the control program P1 is rewritten can be maintained while the control program P1 is being rewritten. Therefore, even if a user is present in the lighting space H1, the user can spend time in the lighting space H1 with little change in the lighting state.

[0113] 5. Fifth Embodiment In the first embodiment, the control program P1 is stopped while the control program P1 is being rewritten. Therefore, even if a user inputs data to an operation unit such as the input unit 74 or the wall switch 75 while the control program P1 is being rewritten, the user input is not reflected in the operation of the lighting device 2. Therefore, in order to reflect the user input in the operation of the lighting device 2, the user needs to input data to the operation unit again after rewriting the control program P1. Such multiple user inputs are time-consuming for the user.

[0114] Therefore, in the fifth embodiment, it is intended that a user input during rewriting of the control program P1 is automatically reflected in the operation of the lighting device 2 after the control program P1 is rewritten.

[0115] The configuration of the lighting system 1 according to the fifth embodiment is the same as the configuration of the lighting system 1 according to the first embodiment, except that the lighting system 1 stores the contents of a user input during rewriting of the control program P1, and controls the lighting device 2 based on the contents of the user input after the control program P1 is rewritten.

[0116] 14 is a diagram showing an example of the operation of the lighting system 1 according to the fifth embodiment. For example, in response to the establishment of an update condition, the external device 7 transmits the update program P3 to the lighting device 2, and the lighting device 2 receives the update program P3. The lighting device 2 executes steps S3, S30, and S31 of the first embodiment as necessary, and then executes steps S4 to S7 to rewrite the control program P1 with the update program P3.

[0117] 14 , in step S20 after the external device 7 has transmitted the update program P3, the user inputs information for a certain lighting device 2 via the input unit 74 or the wall switch 75. Next, in step S21, the second control unit 72 of the external device 7 stores the content of the input signal from the input unit 74 or the wall switch 75 as input content information in the storage unit 73. The input content information may include identification information for identifying the lighting device 2 that is the target of the user input, and information about the lighting state of the lighting device 2.

[0118] As described above, when a user input (step S20) is made while the control program P1 in the lighting device 2 is being rewritten, input content information indicating the content of the user input is stored in the storage unit 73 of the external device 7.

[0119] When the first control unit 5 of the lighting device 2 completes the rewriting of the control program P1, it terminates the startup program P2 and executes the control program P1. Therefore, a process for establishing communication between the lighting device 2 and the external device 7 is performed. In this process, the first control unit 5 transmits a signal to the external device 7 via the first communication unit 4. The signal may include identification information of the external device 7 as the communication destination and identification information of the lighting device 2 as the communication source. The second control unit 72 of the external device 7 receives the signal via the second communication unit 71. The second control unit 72 also transmits a signal to the lighting device 2 as appropriate via the second communication unit 71, and establishes communication in cooperation with the first control unit 5. Here, it is assumed that communication has been established between the lighting device 2, which is the input target of step S20, and the external device 7.

[0120] Next, in step S22, the second control unit 72 reads the input content information from the storage unit 73, and if communication has been established with a lighting device 2 having the identification information included in the input content information, generates an instruction signal corresponding to the lighting state of the input content information. For example, if the input content information indicates an instruction to turn the light source 3 on or off, the second control unit 72 generates an instruction signal to turn the light source 3 on or off. Also, if the input content information indicates the light intensity of the illumination light L1, the second control unit 72 generates an instruction signal to indicate the light intensity of the light source 3. Then, the second control unit 72 transmits the instruction signal to the corresponding lighting device 2 via the second communication unit 71.

[0121] When the first control unit 5 of the lighting device 2 receives the instruction signal through the first communication unit 4, in step S23, it controls the light source 3 based on the instruction signal. Specifically, the first control unit 5 generates a control signal based on the instruction signal and outputs the control signal to the light source drive circuit 30. This causes the light source 3 to emit illumination light L1 with a light intensity based on the instruction signal.

[0122] As described above, the external device 7 stores in the storage unit 73 the contents of user inputs made during the period from when the external device 7 transmits the update program P3 to the lighting device 2 until when it receives a signal from the lighting device 2 after the control program P1 has been rewritten. Therefore, the contents of the user input made during the rewriting of the control program P1 are stored in the storage unit 73. After the control program P1 has been rewritten, the contents of the user input are transmitted to the lighting device 2 as instruction signals, and the lighting device 2 controls the light source 3 based on the instruction signals. In other words, the user inputs made during the rewriting of the control program P1 are reflected in the operation of the lighting device 2 after the control program P1 has been rewritten. Therefore, the user does not need to input information to the input unit 74, wall switch 75, or other operating units again after the control program P1 has been rewritten. This improves user convenience.

[0123] As shown in FIG. 9 , when the external device 7 transmits an update instruction signal to the lighting device 2, the external device 7 may store in the memory unit 73 the contents of the user input that is input during the period from when the external device 7 transmits the update instruction signal to when the external device 7 receives the signal after the control program P1 has been rewritten.

[0124] 6. Sixth Embodiment If updating of the control program P1 fails due to, for example, a malfunction of a lighting device 2, a worker needs to repair or replace the lighting device 2. In a case where the lighting system 1 includes a plurality of lighting devices 2 installed in the installation space H2, if the worker can easily confirm which lighting device 2 in the installation space H2 has malfunctioned, the worker can quickly start the repair or replacement work.

[0125] Therefore, the sixth embodiment aims to notify the user of the installation location of the lighting device 2 in which an abnormality has occurred.

[0126] 15 is a block diagram showing an example of the electrical configuration of the external device 7 of the lighting system 1 according to the sixth embodiment. In the sixth embodiment, the external device 7 further includes a notification unit 76. The notification unit 76 is a device that notifies the user of various information, and includes, for example, either a display such as a liquid crystal display or an audio output unit such as a speaker. The notification unit 76 is electrically connected to the second control unit 72 and is controlled by the second control unit 72.

[0127] In the sixth embodiment, location information D3 is stored in the storage unit 73. The location information D3 is data indicating the installation locations of the plurality of lighting devices 2, and is data that associates the identification information of the lighting devices 2 with the installation locations of the lighting devices 2, as shown in Table 1, for example.

[0128]

[0129] The input unit 74 may receive an input regarding a correspondence between the identification information of the lighting devices 2 and the installation locations of the lighting devices 2. For example, when a worker installs the lighting system 1, the worker inputs the correspondence into the input unit 74. The input unit 74 outputs an input signal indicating the content of the input to the second control unit 72. The second control unit 72 generates location information D3 based on the input signal and stores the location information D3 in the storage unit 73. This associates the identification information of the lighting devices 2 used in communication with the actual installation locations of the lighting devices 2.

[0130] FIG. 16 is a flowchart showing an example of an operation related to abnormality processing of the lighting system 1. In the example of FIG. 16 , in step S50, the second control unit 72 of the external device 7 determines whether or not an abnormality has occurred in each lighting device 2 based on communication with each lighting device 2. For example, when each lighting device 2 successfully completes updating of its control program P1, it operates based on the updated control program P1, and communication between the external device 7 and the lighting device 2 is established. In other words, if the lighting device 2 is normal, the external device 7 can communicate with the lighting device 2 except during the period when the control program P1 is being rewritten. Conversely, if the external device 7 sends a signal to a lighting device 2 during a period other than the period when the control program P1 is being rewritten but does not receive a response, it is considered that an abnormality has occurred in that lighting device 2.

[0131] As a specific example, after a sufficient predetermined time has elapsed since the transmission of the update program P3, the second control unit 72 of the external device 7 transmits a response request signal requiring a response to the lighting device 2 via the second communication unit 71. When the first control unit 5 of the lighting device 2 receives the response request signal via the first communication unit 4, it performs predetermined processing as necessary and then transmits a response signal to the external device 7 via the first communication unit 4. The response request signal and the response signal are not particularly limited, and may be, for example, various signals transmitted and received when establishing communication between the external device 7 and the lighting device 2.

[0132] For example, the second control unit 72 of the external device 7 may determine whether or not a response signal has been received within a predetermined time from the transmission of the response request signal for each lighting device 2. When the second control unit 72 of the external device 7 has received a response signal from all lighting devices 2, all lighting devices 2 are normal, and the abnormality processing operation is terminated.

[0133] On the other hand, if a response signal cannot be received from any of the lighting devices 2, in step S51, the second control unit 72 reads out location information D3 from the memory unit 73 and identifies the installation location of that lighting device 2 based on the identification information of that lighting device 2 and the location information D3.

[0134] Next, in step S52, the second control unit 72 causes the notification unit 76 to notify that an abnormality has occurred in the lighting device 2 and the installation location of the lighting device 2 where the abnormality has occurred.

[0135] As described above, according to the sixth embodiment, when an abnormality occurs in a lighting device 2, the installation location of the lighting device 2 where the abnormality has occurred is notified by the notification unit 76. This allows a worker to quickly identify the installation location of the lighting device 2 where the abnormality has occurred, and can expedite the start of work to repair or replace the lighting device 2.

[0136] As described above, the lighting device 2 and the lighting system 1 have been described in detail. However, the above description is merely an example in all respects, and the lighting device 2 and the lighting system 1 are not limited thereto. It is understood that countless variations not illustrated can be envisioned without departing from the scope of this disclosure. The configurations described in the above embodiments and variations (or aspects) can be combined or omitted as appropriate, as long as they are not mutually inconsistent.

[0137] It goes without saying that all or part of the components constituting each of the above-described embodiments and various modified examples (or each aspect) can be combined as appropriate within the scope of not causing any contradiction.

[0138] For example, in the specific example described above, the lighting device 2 temporarily stores the received update program P3 in the external storage unit 6. This allows for more reliable updating of the control program P1. However, the various configurations and operations described above and the effects brought about by these configurations and operations do not necessarily require the external storage unit 6. For example, in the second to sixth embodiments, the first control unit 5 may rewrite the control program P1 with the received update program P3 without storing the received update program P3 in the external storage unit 6.

[0139] This disclosure includes the following:

[0140] In one embodiment, (1) an illumination device includes a light source that emits illumination light into an illumination space, a light source drive circuit that supplies power to the light source, a first control unit that includes a non-volatile first storage unit that stores a control program that defines control operations related to control of the light source, a first processing circuit that executes the control program to control the light source drive circuit, a non-volatile second storage unit, and a first communication unit that communicates with an external device, and the first control unit receives an update program for the control program from the external device through the first communication unit, stores the received update program in the second storage unit, and rewrites the control program stored in the first storage unit with the update program stored in the second storage unit.

[0141] (2) In the lighting device of (1) above, the first memory unit can also store a startup program that specifies the rewriting operation for rewriting the control program, and the first control unit can receive the update program through the first communication unit in accordance with the control program and store the received update program in the second memory unit, and can execute the startup program with the control program stopped and rewrite the control program with the update program in accordance with the startup program.

[0142] (3) In the lighting device of (2) above, the first control unit can receive an instruction signal regarding the lighting state of the light source from the external device through the first communication unit in accordance with the control program, and can control the light source driving circuit based on the instruction signal.

[0143] (4) In any one of the lighting devices (1) to (3) above, the first control unit can rewrite the control program with the update program when the first sensor does not detect a person in the lighting space.

[0144] (5) In any one of the lighting devices (1) to (4) above, the first control unit can rewrite the control program with the update program when the illuminance of the lighting space measured by the second sensor is equal to or lower than a specified illuminance.

[0145] (6) In the lighting device according to any one of (1) to (5) above, the first control unit can rewrite the control program with the update program when the current time is within a specified time period.

[0146] (7) In any one of the lighting devices (1) to (6) above, the first control unit can rewrite the control program with the update program after storing status information indicating the lighting status of the light source in the first storage unit or the second storage unit, and can control the light source drive circuit based on the status information after rewriting the control program.

[0147] (8) In any one of the lighting devices (1) to (7) above, the light source drive circuit may include a dimmer circuit that supplies power to the light source based on a drive signal, and a dimmer drive circuit that outputs the drive signal to the dimmer circuit, and the first control unit may output a data signal indicating the amount of light of the illumination light and an enable signal to the dimmer drive circuit according to the control program, and the dimmer drive circuit may include a data retention unit that updates a held signal with the input data signal when the enable signal is high, and maintains the held signal regardless of the input data signal when the enable signal is low, and may generate the drive signal based on the held signal.

[0148] (9) A lighting system may include any one of the lighting devices described above in (1) to (8) and the external device. The external device may include a second communication unit that communicates with the first communication unit of the lighting device, a second control unit that transmits the update program to the lighting device through the second communication unit, and a second storage unit that stores status information indicating the lighting status of the light source. The second control unit may store the status information indicating the lighting status of the light source immediately before the control program is rewritten in the second storage unit. After the control program is rewritten, the second control unit may transmit an instruction signal indicating the status information to the lighting device through the second communication unit. The first control unit of the lighting device may receive the instruction signal through the first communication unit and control the light source drive circuit based on the instruction signal.

[0149] (10) A lighting system may include any one of the lighting devices described above in (1) to (8) and the external device. The external device may include a second communication unit that communicates with the first communication unit of the lighting device, an input unit that accepts input to the lighting device, and a second control unit that transmits an instruction signal in response to the input to the input unit and the update program to the lighting device. The second control unit may transmit the instruction signal in response to the input to the input unit during a period in which the first control unit of the lighting device is rewriting the control program to the lighting device via the second communication unit after the control program has been rewritten. The first control unit of the lighting device may receive the instruction signal via the first communication unit and control the light source drive circuit based on the instruction signal.

[0150] (11) A lighting system may include any one of the lighting devices described above in (1) to (8) and the external device. The external device may include a second communication unit that communicates with the first communication unit of each of the plurality of lighting devices, a third storage unit that stores identification information for communication of the plurality of lighting devices and location information indicating a correspondence between the identification information and the installation locations of the plurality of lighting devices, an alarm unit, and a second control unit that transmits the update program to the plurality of lighting devices via the second communication unit. The second control unit may determine whether an abnormality has occurred in each of the plurality of lighting devices based on communication with the plurality of lighting devices via the second communication unit, and when an abnormality has occurred, may notify the alarm unit of the installation location of the lighting device in which the abnormality has occurred based on the identification information and the location information of the lighting device in which the abnormality has occurred.

[0151] REFERENCE SIGNS LIST 1 Lighting system 2 Lighting device 3 Light source 30 Light source drive circuit 31 Dimming circuit 32 Dimming drive circuit 4 First communication unit 5 First control unit 51 First processing circuit 52 First memory unit (first built-in memory unit) 6 Second memory unit (external memory unit) 7 External device 71 Second communication unit 72 Second control unit 73 Third memory unit (memory unit) 74 Input unit 75 Input unit (wall switch) 76 Notification unit 81 First sensor 82 Second sensor

Claims

1. A light source that emits illumination light into an illumination space; a light source driving circuit for supplying power to the light source; a first control unit including a first non-volatile storage unit that stores a control program that defines a control operation related to the control of the light source, and a first processing circuit that executes the control program to control the light source drive circuit; A non-volatile second storage unit; A first communication unit for communicating with an external device; Equipped with The first control unit is receiving an update program for the control program from the external device via the first communication unit; storing the received update program in the second storage unit; The control program stored in the first storage unit is rewritten with the update program stored in the second storage unit.

2. 2. The lighting device according to claim 1, The first storage unit also stores a startup program that specifies a rewrite operation for rewriting the control program, The first control unit is receiving the update program through the first communication unit in accordance with the control program, and storing the received update program in the second storage unit; The lighting device executes the startup program while the control program is stopped, and rewrites the control program with the update program in accordance with the startup program.

3. 3. The lighting device according to claim 2, The first control unit receives an instruction signal regarding the lighting state of the light source from the external device via the first communication unit in accordance with the control program, and controls the light source driving circuit based on the instruction signal.

4. 4. The lighting device according to claim 1, The first control unit rewrites the control program with the update program when a first sensor does not detect a person in the lighting space.

5. 4. The lighting device according to claim 1, The first control unit rewrites the control program with the update program when the illuminance of the illumination space measured by a second sensor is equal to or lower than a specified illuminance.

6. 4. The lighting device according to claim 1, The first control unit rewrites the control program with the update program when the current time is within a specified time period.

7. 4. The lighting device according to claim 1, the first control unit stores status information indicating an illumination state of the light source in the first storage unit or the second storage unit, and then rewrites the control program with the update program, and controls the light source driving circuit based on the status information after rewriting the control program.

8. 4. The lighting device according to claim 1, The light source driving circuit includes: a dimming circuit that supplies power to the light source based on a drive signal; a dimming drive circuit that outputs the drive signal to the dimming circuit; Including, the first control unit outputs a data signal indicating the amount of the illumination light and an enable signal to the dimming drive circuit in accordance with the control program; The dimming drive circuit includes: a data holding unit that updates a held signal with the input data signal when the enable signal is in a high state, and that maintains the held signal regardless of the input data signal when the enable signal is in a low state; A lighting device that generates the drive signal based on the sustain signal.

9. One or more lighting devices according to any one of claims 1 to 3; The external device Equipped with The external device is A second communication unit that communicates with the first communication unit of the lighting device; A second control unit that transmits the update program to the lighting device through the second communication unit; a second storage unit that stores status information indicating an illumination status of the light source; Including, the second control unit stores in the second storage unit status information indicating the illumination state of the light source immediately before the control program is rewritten, and after the control program is rewritten, transmits an instruction signal indicating the status information to the illumination device via the second communication unit; The first control unit of the lighting device receives the instruction signal through the first communication unit and controls the light source drive circuit based on the instruction signal.

10. One or more lighting devices according to any one of claims 1 to 3; The external device Equipped with The external device is A second communication unit that communicates with the first communication unit of the lighting device; an input unit that receives an input for the lighting device; a second control unit that transmits an instruction signal corresponding to an input to the input unit and the update program to the lighting device; Including, the second control unit transmits the instruction signal corresponding to the input to the input unit during a period in which the first control unit of the lighting device is rewriting the control program to the lighting device via the second communication unit after the control program is rewritten; The first control unit of the lighting device receives the instruction signal through the first communication unit and controls the light source drive circuit based on the instruction signal.

11. A plurality of lighting devices according to any one of claims 1 to 3; The external device Equipped with The external device is a second communication unit that communicates with the first communication unit of each of the plurality of lighting devices; a third storage unit configured to store identification information for communication with the plurality of lighting devices and location information indicating a correspondence relationship between the plurality of lighting devices and installation locations; A notification department; a second control unit that transmits the update program to the lighting devices via the second communication unit; Including, The second control unit is determining whether or not an abnormality has occurred in each of the plurality of lighting devices based on communication with the plurality of lighting devices via the second communication unit; a notification unit that notifies an installation location of the lighting device in which an abnormality has occurred, based on the identification information and the location information of the lighting device in which an abnormality has occurred, when the abnormality has occurred.