Control method, control circuit, and floodlight system

Abstract

To provide control method and the like which can restrain temperature of an IR light source from rising.SOLUTION: A control method includes: an acquisition step (S110) of acquiring an operational signal which indicates operation of an IR (Infrared) camera having sensitiveness in an IR area; and a control step (S120) of repeatedly controlling increase and decrease of light volume of IR light emitted by the IR light source in response to the operation of the IR camera on the basis of the operational signal.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a control method, a control circuit, and a light projection system.

Background Art

[0002] Conventionally, there is an infrared imaging system that irradiates a subject with infrared rays (also referred to as IR (Infrared) light) and images the infrared rays reflected from the subject (see, for example, Patent Document 1). Patent Document 1 discloses an infrared imaging system in which a second infrared irradiation unit irradiates infrared rays in synchronization with a period during which an infrared light receiving unit receives infrared rays irradiated from a first infrared irradiation unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The temperature of a substrate on which an IR light source such as an LED (Light Emitting Diode) that emits IR light is placed rises when the IR light source continuously emits IR light for a long time. When the temperature rises, there is a risk that the IR light source will malfunction.

[0005] The present invention provides a control method and the like that can suppress the temperature rise of an IR light source.

Means for Solving the Problems

[0006] A control method according to an aspect of the present invention includes an acquisition step of acquiring an operation signal indicating the operation of an IR camera having sensitivity in the IR (Infrared) region, and a control step of repeatedly controlling an increase or decrease in the amount of IR light emitted by an IR light source corresponding to the operation of the IR camera based on the operation signal.

[0007] Furthermore, a control circuit according to one aspect of the present invention includes an acquisition unit that acquires an operation signal indicating the operation of an IR camera having sensitivity to the IR region, and a control unit that repeatedly controls the increase or decrease of the amount of IR light emitted by an IR light source in response to the operation of the IR camera based on the operation signal.

[0008] Furthermore, a light projection system according to one aspect of the present invention comprises the control circuit described above and the IR light source. [Effects of the Invention]

[0009] According to one aspect of the present invention, such as a control method, the temperature rise of an IR light source can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a front view showing a vehicle according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the configuration of the light-emitting system according to the embodiment. [Figure 3] Figure 3 is a diagram illustrating a first example of controlling an IR light source according to an embodiment. [Figure 4] Figure 4 is a diagram illustrating a second example of controlling an IR light source according to an embodiment. [Figure 5] Figure 5 is a flowchart showing the processing procedure of the control circuit according to the embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0012] Note that each figure is a schematic diagram and is not necessarily drawn precisely. Therefore, for example, scales in each figure do not necessarily match. Also, each figure is a schematic diagram in which emphasis, omission, and ratio adjustment are appropriately made to show the present invention, and may differ from the actual shape, positional relationship, and ratio. Further, in each figure, substantially the same components are denoted by the same reference numerals, and duplicate explanations may be omitted or simplified.

[0013] (Embodiment) [Configuration] FIG. 1 is a front view showing a vehicle 300 according to an embodiment. FIG. 2 is a block diagram showing the configuration of a light projection system 100 according to the embodiment. In FIG. 1, the IR light emitted from the projector 110 is shown by a broken line.

[0014] The vehicle 300 is a moving body such as an automobile or a motorcycle provided with the light projection system 100. In the present embodiment, the vehicle 300 is an automobile.

[0015] The vehicle 300 includes a vehicle body 310, a side mirror 320, a power supply 330, an IR camera 200, and a light projection system 100.

[0016] The vehicle body 310 is a vehicle main body to which the side mirror 320 is attached to a side portion and in which a driver gets in and drives. The vehicle body 310 supports the side mirror 320 at both side portions of the vehicle body 310.

[0017] The side mirror 320 is a mirror attached to a side portion of the vehicle body 310. In the present embodiment, a projector 110 and an IR camera 200 are attached to the side mirror 320.

[0018] Note that in the present embodiment, the vehicle 300 includes a projector 110 and an IR camera 200 in each of the side mirrors 320 located on both sides of the vehicle body 310, but the projector 110 and the IR camera 200 may be provided only in one of the side mirrors 320.

[0019] The power supply 330 is a battery that supplies power to various electrical devices provided in the vehicle 300.

[0020] The IR camera 200 is a camera having sensitivity in the IR region. Specifically, the IR camera 200 images an object by detecting IR light emitted from the projector 110 and reflected by the object such as a road surface. That is, the IR camera 200 is attached to the side mirror 320 so as to be able to detect the light emitted by the IR light source 111 and reflected by the road surface. The IR camera 200 generates an image of the road surface by detecting the light reflected by the road surface around the vehicle 300. As described above, the IR light source 111 is, for example, an IR light source that emits IR light, and the IR camera 200 detects the IR light emitted from the IR light source 111, specifically, the IR light emitted from the IR light source 111 and reflected by the road surface.

[0021] The IR camera 200 is realized by an imaging device having sensitivity to IR light, such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, for example.

[0022] The operation of the IR camera 200, such as the exposure timing (imaging timing) and exposure time, is controlled by a control device (not shown) including, for example, a processor and a memory that stores a control program executed by the processor. The control device outputs an operation signal (the "camera synchronization signal" shown in FIG. 2) indicating the operation (imaging process) of the IR camera 200 to the power supply circuit 120 (more specifically, the control circuit 121). The control device may be included in the IR camera 200.

[0023] The operation signal is a signal indicating the operation of the IR camera 200. Specifically, the operation signal indicates the timing at which the IR camera 200 images, that is, the exposure timing. For example, the operation signal includes information indicating the exposure time of the IR camera 200 and the period in which the exposure is repeated.

[0024] The IR region to which the IR camera 200 is sensitive is, for example, a wavelength region that at least partially coincides with the wavelength region of the IR light emitted by the IR light source 111. For example, the IR camera 200 only needs to be sensitive to such an IR region, and may also be sensitive to the visible region (for example, light wavelengths of about 400 nm to 800 nm).

[0025] Furthermore, the IR camera 200 may be controlled by the control circuit 121, which will be described later.

[0026] The light projection system 100 is an optical unit for emitting IR light. In this embodiment, the light projection system 100 is an optical unit that emits IR light toward the road surface and detects the reflected light that is reflected by the road surface.

[0027] As shown in Figure 2, the floodlight system 100 comprises a floodlight 110 and a power supply circuit 120.

[0028] The floodlight 110 is a light-emitting device that emits IR light. The floodlight 110 and IR camera 200, which are part of the floodlight system 100, are positioned, for example, on the outer surface of the vehicle 300. Specifically, the floodlight 110 is mounted on the vehicle 300 in a position that allows it to illuminate the road surface around the vehicle 300 when the light is directed downwards. In this embodiment, the floodlight 110 is mounted below the side mirror 320.

[0029] Furthermore, the exterior surface of the vehicle 300 includes not only the outer surface of the vehicle body 310, but also the sides of the side mirrors 320, the underside of the side mirrors 320, the overhang surfaces of the vehicle body 310, and the outer surfaces of the doors of the vehicle 300. The overhang surface is the lower part of the vehicle body 310 and is inclined with respect to the vertical. Also, when the vehicle 300 is said to have the floodlight 110 and IR camera 200 on its exterior surface, it includes not only cases where the floodlight 110 and IR camera 200 are located on the exterior surface, but also cases where they are located near the exterior surface and inside the vehicle 300.

[0030] In the example shown in Figure 1, the vehicle body 310, the floodlight 110, and the IR camera 200 are arranged in this order. The vehicle body 310, the IR camera 200, and the floodlight 110 may also be arranged in this order.

[0031] The floodlight 110 comprises an IR light source 111 and a thermistor 112.

[0032] The IR light source 111 is mounted on the vehicle 300 together with the IR camera 200 and is a light source that emits light onto the road surface. In this embodiment, the IR light source 111 emits near-infrared light.

[0033] The IR light (near-infrared light) emitted by the IR light source 111 is, for example, light with a wavelength range of 800 nm or more. The IR light emitted by the IR light source 111 may also have a wavelength range of 910 nm to 970 nm.

[0034] The IR camera 200 may be positioned on the opposite side of the IR light source 111 from the direction in which the IR light source 111 emits light (downward in this embodiment). In other words, the IR camera 200 may be positioned above the IR light source 111. In this embodiment, the IR camera 200 is positioned above the light source 110.

[0035] According to this, the direct incidence of IR light emitted from the IR light source 111 into the IR camera 200 without being reflected by the road surface is suppressed.

[0036] Furthermore, the floodlight system 100 may be located between the IR camera 200 and the floodlight 110 and may include a light-shielding section that blocks the light emitted by the floodlight 110. The light-shielding section only needs to have the function of blocking the light, and may be reflective or absorbing to the light.

[0037] The thermistor 112 is a temperature sensor for detecting the temperature of the IR light source 111. The temperature of the IR light source 111, as used here, includes not only the temperature of the light-emitting elements such as LEDs that emit IR light, but also the temperature of the substrate on which the light-emitting elements are mounted, or the ambient temperature of the surrounding environment where the IR light source 111 is located. In this embodiment, the thermistor 112 detects the temperature of the substrate on which the light-emitting elements are mounted as the temperature of the IR light source 111. The information indicating the temperature of the IR light source 111 detected by the thermistor 112 is output to the control circuit 121.

[0038] The power supply circuit 120 is a circuit for supplying power to the floodlight 110. Specifically, the power supply circuit 120 supplies power from the power supply 330 to the floodlight 110.

[0039] In this embodiment, one power supply circuit 120 is provided for each floodlight 110. However, one power supply circuit 120 may be provided for two or more floodlights 110.

[0040] In this embodiment, the power supply circuit 120 is located on the vehicle body 310. The power supply circuit 120 may also be located on the side mirror 320.

[0041] The power supply circuit 120 includes a control circuit 121.

[0042] The control circuit 121 is a circuit that controls the IR light source 111. Specifically, the control circuit 121 controls the amount of IR light emitted by the IR light source in response to the operation of the IR camera.

[0043] The control circuit 121 is implemented, for example, by a microcomputer.

[0044] The control circuit 121 may be implemented using a control IC such as a logic IC (Integrated Circuit). By implementing the control circuit 121 using a control IC such as a logic IC, a general-purpose IC can be used as is, thus potentially reducing the manufacturing cost of the control circuit 121.

[0045] Functionally, the control circuit 121 includes an acquisition unit 122 and a control unit 123.

[0046] The acquisition unit 122 is a processing unit that acquires operation signals indicating the operation of an IR camera 200 which has sensitivity in the IR region. For example, the control circuit 121 is connected to a control device that controls the IR camera 200 by a communication line or the like.

[0047] The control unit 123 is a processing unit that controls the IR light source 111. Specifically, the control unit 123 repeatedly controls the increase or decrease of the amount of IR light emitted by the IR light source 111 in accordance with the operation of the IR camera 200, based on the operation signal acquired by the acquisition unit 122. More specifically, the control unit 123 repeatedly controls the increase or decrease of the amount of IR light emitted by the IR light source 111 over multiple exposures of the IR camera 200, based on the operation signal acquired by the acquisition unit 122. In other words, the control unit 123 increases the amount of IR light emitted by the IR light source 111 when the IR camera 200 is exposed, and decreases the amount of IR light emitted by the IR light source 111 when the IR camera 200 is not exposed. For example, the control unit 123 controls the on / off state of the IR light source 111 and the amount of IR light emitted by the IR light source by controlling the amount of current (drive current) supplied from the power supply 330 to the IR light source 111 (i.e., for current).

[0048] The control unit 123 controls the IR light source 111, for example, to synchronize the timing of the emission of IR light from the IR light source 111 with the exposure timing of the IR camera 200. In other words, the control unit 123 synchronizes and controls the IR light source 111 and the IR camera 200 so that the IR camera 200 can properly detect the reflected light that is reflected off the road surface from the light emitted by the IR light source 111.

[0049] Figure 3 is a diagram illustrating a first example of the control of the IR light source 111 according to the embodiment. Figure 3(a) shows the exposure (imaging) timing and exposure time of the IR camera 200. In Figure 3(a), "on" indicates that the IR camera 200 is exposing, and "off" indicates that the IR camera 200 is not exposing. Figure 3(b) shows the IR light emission timing of the IR light source 111. In Figure 3(b), "on" indicates that the IR light source 111 is emitting IR light, and "off" indicates that the IR light source 111 is not emitting IR light.

[0050] The acquisition unit 122 acquires an operation signal indicating the operation of the IR camera 200, for example, as shown in Figure 3(a). Based on the operation signal acquired by the acquisition unit 122, the control unit 123 controls the IR light source 111 so that it turns on when the IR camera 200 is on. For example, if the IR camera 200 is turned on at time t1, the control unit 123 controls the IR light source 111 to turn on at time t1. Also, for example, if the IR camera 200 is turned off at time t2, the control unit 123 controls the IR light source 111 to turn off at time t2.

[0051] Thus, for example, the operation signal indicates the operating cycle of the IR camera 200. The control unit 123 also periodically controls the on / off state of the IR light source 111 in conjunction with the operating cycle of the IR camera 200.

[0052] The control unit 123 may repeatedly control the increase or decrease in the amount of IR light emitted by the IR light source 111 by repeatedly turning the IR light source 111 on and off, or it may repeatedly control the increase or decrease in the amount of IR light emitted by the IR light source 111 by controlling the amount of IR light emitted.

[0053] For example, the control unit 123 may control the output of the IR light from the IR light source 111 as shown in Figure 3(b), such as 0% (off) → 100% (on) → 0% (off) → 100% (on) → ... or as 0% → 50% → 0% → 50% → .... Alternatively, the control unit 123 may not turn off the IR light source 111 during periods when the IR camera 200 may be exposed, and may control it as 5% → 100% → 5% → 100% → ... or as 5% → 50% → 5% → 50% → ....

[0054] The control unit 123 controls the amount of IR light emitted by the IR light source 111 by, for example, synchronizing the IR camera 200 with the IR light source 111 using PWM (Pulse with Modulation) control (PWM lighting). This reduces the amount of heat generated compared to when the IR light source 111 is driven with a constant current, allowing the If (forward current) to be increased.

[0055] Alternatively, the control unit 123 may control the amount of IR light emitted by the IR light source 111 by controlling the amount of current supplied to the IR light source 111, rather than using PWM control.

[0056] The acquisition unit 122 and the control unit 123 are implemented, for example, by a memory for storing the program and a processor for executing the program.

[0057] The amount of IR light emitted by the IR light source 111 is not particularly limited. For example, when the output of the IR light from the IR light source 111 is 100%, the illuminance on the road surface is 1.0 × 10⁻¹⁰. -3 W / m 2 Light is shone in the manner described above. This allows the IR camera 200 to accurately image the white lines of the driving lane.

[0058] Furthermore, the control unit 123 does not need to control the on / off state of the IR light source 111 to perfectly match the operating cycle (on / off cycle) of the IR camera 200. For example, the control unit 123 may have some gaps in its control so as not to always turn on the IR light source 111 even when the IR camera 200 is on.

[0059] Furthermore, the control unit 123 may control the IR light source 111 to turn on a little before (for example, a few milliseconds) the timing when the IR camera 200 is turned on. For example, if the IR camera 200 is turned on at time t1, the control unit 123 may control the IR light source 111 to turn on before time t1. In this way, the timing at which the IR light source 111 is turned on may be slightly delayed from the timing at which the IR camera 200 is turned on. This is because there is a slight time lag between when current starts flowing through the IR light source 111 and when the area illuminated by the IR light source 111 becomes sufficiently bright.

[0060] Furthermore, the control unit 123 may control the IR light source 111 so that for each exposure time (four times in the example shown in Figure 3) during which the IR camera 200 is exposed, the light emission time is longer than the exposure time, and the exposure time is included in the total exposure time of the IR camera 200 (i.e., the time it is on). For example, if the IR camera 200 is turned on at time t1 and turned off at time t2, the control unit 123 may control the IR light source 111 to be turned on before time t1 and turned off after time t2 (for example, a few milliseconds later).

[0061] Furthermore, for example, the control unit 123 derating controls the IR light source 111 based on its temperature. For example, the acquisition unit 122 acquires the temperature of the IR light source 111 (more specifically, temperature information indicating the temperature) from the thermistor 112 in addition to the operation signal. As described above, the control unit 123 repeatedly controls the increase or decrease of the amount of IR light emitted by the IR light source 111 based on the operation signal. Also, the control unit 123 controls the amount of light when the IR light source 111 is turned on, for example, based on the temperature of the IR light source 111. For example, when the temperature of the IR light source 111 rises, the control unit 123 controls the current value supplied to the IR light source 111 to decrease. Here, control to decrease the current value means, for example, changing the duty cycle in PWM control or reducing the maximum value of the current supplied to the IR light source 111. In this way, for example, the control unit 123 controls the reduction of the drive current of the IR light source 111 according to the temperature of the IR light source 111.

[0062] The derating information indicating the drive current of the IR light source 111 in relation to the temperature of the IR light source 111 can be arbitrarily determined and is not particularly limited. The derating information is stored in advance in the memory of the control circuit 121, for example.

[0063] Figure 4 is a diagram illustrating a second example of the control of the IR light source 111 according to the embodiment. Figure 4(a) shows the exposure timing and exposure time of the IR camera 200. In Figure 4(a), "on" indicates that the IR camera 200 is exposing, and "off" indicates that the IR camera 200 is not exposing. Figure 4(b) shows the IR light emission timing and output of the IR light source 111. In Figure 4(b), "output 100%" indicates that the IR light source 111 is emitting IR light at 100% output, "output 50%" indicates that the IR light source 111 is emitting IR light at 50% output, and "output 0%" indicates that the IR light source 111 is not emitting IR light.

[0064] As shown in Figure 4(b), for example, suppose the control unit 123 controls the output of the IR light from the IR light source 111 based on the operating signal, such as 0% → 100% → 0% → 100% → 0%. Here, for example, suppose that at time t3, the temperature of the IR light source 111 exceeds a predetermined temperature (also called the first threshold). In this case, the control unit 123 determines the output of the IR light from the IR light source 111 based on the temperature and derating information of the IR light source 111, and controls the current supplied to the IR light source 111 to achieve the determined output. As shown in Figure 4(b), for example, when the IR light is emitted from the IR light source 111 after time t3, the control unit 123 controls the output of the IR light from the IR light source 111, such as 0% → 75% → 0% → 50%.

[0065] For example, if the temperature of the IR light source 111 becomes very high, for example, if it exceeds the second threshold, the control unit 123 may keep the IR light source 111 off at predetermined intervals when the IR camera 200 is turned on.

[0066] The first and second thresholds described above can be determined arbitrarily and are not particularly limited. Information indicating the first and second thresholds is pre-stored, for example, in the memory of the control circuit 121.

[0067] [Processing Procedure] Figure 5 is a flowchart showing the processing procedure of the control circuit 121 according to the embodiment.

[0068] First, the acquisition unit 122 acquires an operation signal indicating the operation of the IR camera 200, which is sensitive to the IR region (S110). The operation signal includes information such as the timing of when the IR camera 200 takes an image and the exposure period. The acquisition unit 122 repeatedly acquires the operation signal from the control circuit that controls the IR camera 200, for example, each time the IR camera 200 performs an imaging process (specifically, when the IR camera 200 is about to take an image).

[0069] Furthermore, if the IR camera 200 operates periodically at a predetermined interval, the acquisition unit 122 may acquire an operation signal indicating that interval.

[0070] Next, the control unit 123 repeatedly controls the increase or decrease of the amount of IR light emitted by the IR light source 111 in response to the operation of the IR camera 200, based on the operation signal (S120). For example, based on the operation signal, the control unit 123 determines the timing and duration (period) for emitting IR light from the IR light source 111, and controls the IR light source 111 to emit IR light at the determined timing and for the determined duration.

[0071] When derating control is performed, for example, the acquisition unit 122 repeatedly acquires the temperature of the IR light source 111 (more specifically, temperature information indicating the temperature) from the thermistor 112. When the temperature of the IR light source 111 is above a predetermined temperature, the control unit 123 controls the amount of IR light emitted from the IR light source 111 by controlling the current supplied to the IR light source 111 according to the temperature of the IR light source 111. For example, the control unit 123 controls the IR light source 111 so that the amount of IR light emitted from the IR light source 111 decreases as the temperature of the IR light source 111 increases by reducing the current supplied to the IR light source 111.

[0072] [Effects, etc.] The following describes examples of inventions that can be obtained from the disclosures in this specification, and explains the effects that can be obtained from these examples.

[0073] Invention 1 is a control method that includes an acquisition step (S110) of acquiring an operation signal indicating the operation of an IR camera 200 having sensitivity to the IR region, and a control step (S120) of repeatedly controlling the increase or decrease of the amount of IR light emitted by the IR light source 111 in response to the operation of the IR camera 200 based on the operation signal.

[0074] According to this, for example, by controlling the IR light source 111 so that the amount of light emitted from the IR light source 111 is increased when the IR camera 200 is taking an image, and so that the amount of light emitted from the IR light source 111 is decreased when the IR camera 200 is not taking an image, it is possible to suppress the unnecessary emission of IR light from the IR light source 111. Therefore, it is possible to suppress unnecessary heat generation of the IR light source 111. Accordingly, according to one aspect of the present disclosure, the temperature rise of the IR light source 111 can be suppressed.

[0075] Invention 2 is the control method described in Invention 1, wherein the operation signal indicates the operation period for which the IR camera 200 takes images, and in the control step, the on / off switching of the IR light source 111 is periodically controlled in conjunction with the operation period of the IR camera 200.

[0076] According to this, when the IR camera 200 captures, for example, a moving image, the on / off switching of the IR light source 111 is periodically controlled in accordance with the timing of the IR camera 200 capturing the image. This allows the IR camera 200 to properly receive reflected light from objects emitted by the IR light source 111, while also suppressing unnecessary heat generation by the IR light source 111.

[0077] Invention 3 is a control method according to Invention 1 or 2, wherein the acquisition step further acquires the temperature of the IR light source 111, and the control step further derating-controls the IR light source 111 based on the temperature of the IR light source 111.

[0078] According to this, even if the temperature of the IR light source 111 does not drop to a desired temperature despite repeated control of increasing or decreasing the amount of IR light emitted by the IR light source 111, the occurrence of failure due to overheating of the IR light source 111 can be suppressed.

[0079] Invention 4 is a control circuit 121 comprising an acquisition unit 122 that acquires an operation signal indicating the operation of an IR camera 200 having sensitivity in the IR region, and a control unit 123 that repeatedly controls the increase or decrease of the amount of IR light emitted by an IR light source 111 in accordance with the operation of the IR camera 200 based on the operation signal.

[0080] According to this, the control method will have the same effect as the control method according to one aspect of the present disclosure.

[0081] Invention 5 is a light projection system 100 comprising a control circuit 121 and an IR light source 111.

[0082] According to this, the control method will have the same effect as the control method according to one aspect of the present disclosure.

[0083] (Other embodiments) Although the control methods and other aspects related to the embodiments have been described above, the present invention is not limited to the embodiments described above.

[0084] For example, in the above embodiment, an LED was used as an example of a solid-state light-emitting element in the IR light source, but a semiconductor light-emitting element such as a semiconductor laser, or a solid-state light-emitting element such as an organic EL (Electro-Luminescence) element or an inorganic EL element may also be used.

[0085] Furthermore, for example, the IR light source may be implemented as an SMD (Surface Mount Device) LED module, or as a so-called COB (Chip On Board) LED module in which the LED chip is directly mounted on the substrate.

[0086] Furthermore, the number of IR light sources provided by the floodlight is not particularly limited. For example, the IR light source only needs to be able to illuminate the road surface at the above-mentioned location, and may be realized by a single light-emitting unit. This single light-emitting unit may be attached to a side mirror, for example, or to the vehicle body.

[0087] Furthermore, the placement of floodlights on a vehicle is not particularly limited. All floodlights may be placed on the vehicle body, or all floodlights may be placed on the side mirrors.

[0088] Furthermore, the IR camera may be mounted on the vehicle body rather than on the side mirror.

[0089] Furthermore, the number of IR cameras placed on a vehicle is not particularly limited. There may be one or more IR cameras on a vehicle. Also, the number of IR light sources and IR cameras placed on a vehicle may be the same or different.

[0090] Furthermore, in the above embodiment, each component (each processing unit) may be realized by executing a software program suitable for each component. Each component may also be realized by a program execution unit such as a CPU (Central Processing Unit) or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0091] Furthermore, each component may be implemented by hardware. Each component may also be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or they may be separate circuits. Also, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0092] Furthermore, the general or specific embodiments of this disclosure may be implemented in systems, apparatus, methods, integrated circuits, computer programs, or non-temporary recording media such as computer-readable CD-ROMs. They may also be implemented in any combination of systems, apparatus, methods, integrated circuits, computer programs, and recording media.

[0093] Furthermore, this disclosure may be implemented as an imaging system comprising a floodlight, an IR camera, and a control circuit. In this case, the control circuit may control the exposure timing and exposure time of the IR camera, etc.

[0094] Furthermore, the floodlight system may include sensors such as an illuminance sensor that detects the amount of light outside the vehicle. The control unit 123 controls the emission of IR light from the IR light source based on an operation signal if the amount of light detected by the sensor is less than a predetermined value, and does not need to emit IR light from the IR light source if it is above the predetermined value.

[0095] Furthermore, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art could conceive, or forms realized by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention. [Explanation of Symbols]

[0096] 100 Floodlight Systems 111 IR light source 121 Control Circuit 122 Acquisition Department 123 Control Unit 200 IR cameras

Claims

1. An acquisition step to acquire an operating signal indicating the operation of an IR (Infrared) camera that is sensitive to the IR region, The control step includes repeatedly controlling the increase or decrease of the amount of IR light emitted by the IR light source in response to the operation of the IR camera, based on the aforementioned operation signal. In the control step, while the amount of IR light is repeatedly increased or decreased, the amount of IR light emitted from the IR light source is not set to zero. Control method.

2. The aforementioned operation signal indicates the operation cycle captured by the IR camera. In the control step, the on / off switching of the IR light source is periodically controlled in conjunction with the operating cycle of the IR camera. The control method according to claim 1.

3. In the acquisition step, the temperature of the IR light source is further acquired. In the control step, the IR light source is further derated based on the temperature of the IR light source. The control method according to claim 1 or 2.

4. An acquisition unit that acquires an operating signal indicating the operation of an IR camera that has sensitivity in the IR region, The system includes a control unit that, based on the aforementioned operation signal, repeatedly controls the increase or decrease of the amount of IR light emitted from the IR light source in response to the operation of the IR camera. Control circuit.

5. The control circuit according to claim 4, The IR light source comprises, Floodlighting system.

Images