CN115499972A - Current output circuit, light source device, method for controlling current output circuit, and recording medium - Google Patents

Abstract

The invention provides a current output circuit, a light source device, a control method of the current output circuit and a recording medium, wherein a capacitor can be flexibly configured and the sound can be reduced. The current output circuit includes a circuit unit having a first switching unit for switching the presence/absence of output of a current, a second switching unit for switching the presence/absence of energization from a power supply source, and a capacitor connected to the first switching unit and the second switching unit. The control unit instructs the first switching unit to periodically switch the presence or absence of current output, and instructs the second switching unit to perform a switching operation with a duty ratio smaller than that in the case where current output is performed by the first switching unit, so as to cause current to flow between the supply source and the second switching unit when current output is not performed by the first switching unit.

Description

Current output circuit, light source device, method for controlling current output circuit, and recording medium

Technical Field

The invention relates to a current output circuit, a light source device, a control method of the current output circuit, and a recording medium.

Background

In recent years, ceramic capacitors using a ferroelectric have been widely used as large-capacity capacitors. In a capacitor using a ferroelectric, deformation occurs according to an applied voltage. There are the following problems: when the distortion is periodically generated by the ac voltage and transmitted to a substrate or the like to which the capacitor is fixed, or resonates, a sound is generated by the distortion at the audible frequency band. Such ringing due to resonance is difficult to theoretically or numerically predict in advance and design in such a manner as to avoid occurrence. In contrast, japanese patent application laid-open No. 2018-078137 discloses a technique of reducing vibration and squeal of a circuit board as a whole by arranging capacitors having opposite phases of vibration characteristics in the vicinity of the circuit board.

Disclosure of Invention

However, according to the method of using the capacitor, there are problems as follows: it is difficult to operate the capacitors in an anti-phase oscillation manner, and it is difficult to efficiently arrange the substrates because of restrictions on the arrangement of the plurality of capacitors.

The invention aims to provide a current output circuit, a light source device, a control method of the current output circuit and a storage medium, wherein a capacitor can be more flexibly arranged and the ringing sound can be reduced.

Means for solving the problems

In order to achieve the above object, a current output circuit of the present invention is characterized in that,

comprises a circuit part and a control part, wherein,

the circuit unit includes:

a first switching unit for switching the output of current;

a second switching unit that switches whether or not power is supplied from a power supply source; and

a capacitor connected to the first switching part and the second switching part,

the control part is used for controlling the operation of the motor,

instructing the first switching section to periodically switch the presence or absence of the output,

when the output is not performed by the first switching unit, the second switching unit is instructed to perform a switching operation at a duty ratio smaller than that in a case where the output is performed by the first switching unit, thereby causing the current to flow between the second switching unit and the supply source.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the capacitor can be more flexibly arranged and ringing noise can be reduced.

Drawings

Fig. 1 is a block diagram showing a functional configuration of a light source device according to the present embodiment.

Fig. 2 is a diagram illustrating a circuit configuration of the current output circuit.

Fig. 3 is a diagram illustrating an input/output pattern of current.

Fig. 4 is a flowchart showing a control procedure of the current input/output control process.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a block diagram showing a functional configuration of a light source device 1 according to the present embodiment.

The light source device 1 is a device that emits light in accordance with an output image as a projection device (projector). The light source device 1 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a communication Unit 14, an operation reception Unit 15, a projection Unit 16, a display drive Unit 17, a cooling Unit 18, a current input/output Unit 20, and the like. The CPU11 is connected to each unit via a bus.

The CPU11 is a hardware processor that totally controls the operation of the light source device 1. The CPU11 is not limited to one, and a plurality of CPUs may be operated in a distributed manner according to functions and the like. For example, the CPU11 performs the control operation of the circuit unit 220 as described later, but may have a dedicated CPU for performing the control operation.

The ROM12 is a nonvolatile memory such as a mask ROM and a flash memory, and stores a program 121, various setting data, and the like. The program 121 includes a control program for projecting and outputting light emission and emission to each pixel position of an image corresponding to image data acquired from the outside. The setting data includes a light amount setting 122.

The RAM13 provides the CPU11 with a memory space for work, and stores temporary data.

The light amount setting 122 stored in the ROM12 includes an operation setting according to the intensity (emission intensity) of light (projection light) emitted from the light emitting section 161 of the projecting section 16. The appropriate intensity of the light emitted from the light source device 1 depends on the brightness of the place where the emitted light is projected, the distance of the projection surface, and the like. According to these, the light emission intensity can be adjusted.

The CPU11, ROM12, RAM13, and the like described above constitute a computer of the present embodiment.

The communication unit 14 receives input of image data of the projection target image from an external device, acquires the image data, and performs processing such as expansion as necessary. The communication unit 14 includes, for example, an input terminal and a wireless LAN interface. The input terminal is connected to a cable between the input terminal and an external device. Examples of the input terminal include various terminals related to analog RGB signals, USB (Universal Serial Bus), HDMI (High Definition Multimedia Interface), and the like, and a plurality of these terminals can be selectively used. The wireless LAN interface receives and demodulates radio waves from an external device via an antenna (not shown) in accordance with the standard of wireless LAN (IEEE 802.11 or the like). The wireless LAN interface has a network card or the like, and can perform communication connection from an external device via the wireless LAN based on the identification information.

The operation receiving unit 15 receives an input operation from the outside such as a user, and outputs an input signal corresponding to the received operation content to the CPU11. The operation receiving unit 15 includes, for example, a push switch or the like that is easily operated by a user. The push switch may be provided in plurality in the form of a push switch for on/off switching of power supply and a push switch for various settings. The operation reception unit 15 may have another remote controller or the like. In this case, the operation receiving unit 15 may include a receiving unit that receives a signal (such as an infrared signal) from the remote controller.

Here, the projection unit 16 generates light of RYGB colors, and emits projection light using the light. The projection unit 16 obtains projection light by emitting the projection light from the light emission port in the projection direction at a pixel position and timing corresponding to image data of the projection target image. The projection unit 16 includes a light emitting unit 161 (light source unit), an optical system 162, a rotation driving unit 163, a rotation motor 164, and the like.

The Light Emitting unit 161 includes, for example, a laser Diode (laser Diode), an LED (Light Emitting Diode), or the like, and emits Light of a predetermined wavelength with an intensity corresponding to an input current. Here, for example, a red light emitting LED (R-LED) and a blue light emitting laser diode (B-LD) are provided, and red light and blue light are generated, respectively. The light emission intensity of the light emitting unit 161 can be changed within a predetermined range defined by the current intensity or the like.

The optical system 162 appropriately reflects and converges the generated light of each color, and guides the light to the light exit port of the light source device 1. The optical system 162 has a part or all of various optical lenses, prisms, mirrors, filters, and the like. At least a part of these components is movable in the optical axis direction for adjusting the focal position. The optical system 162 may include a movable mirror, for example, a digital (micro) mirror device (DMD) corresponding to the number of display pixels.

The rotation driving unit 163 rotates the rotation motor 164 at a predetermined rotation speed.

The rotation motor 164 rotates a fluorescent plate, not shown. The fluorescent plate receives blue light and emits green light, that is, as described above, RGB (red, green, blue) 3-color and Y-color (yellow) light can be emitted by the blue and red light emitting portions 161 and the fluorescent plate.

The display driving unit 17 performs an operation of adjusting the emission position and timing of light from the light emission port based on image data of a projection target. The display driving unit 17 operates the movable mirror or the like, and changes the reflection angle between the timing when light of each wavelength is emitted from each pixel and the timing when light of each wavelength is not emitted, thereby emitting light of a desired wavelength band from the light emission port only at the emission timing.

The cooling unit 18 discharges heat from each portion associated with light emission of the light emitting unit 161. The cooling unit 18 includes an air blowing drive unit 181, an air blowing motor 182, and the like. The blower motor 182 rotates a fan that discharges heat from the inside of the housing of the light source device 1. The blower driving unit 181 rotationally drives the blower motor 182 at a predetermined rotational speed. The operation of the blower motor 182 (fan) may be started together with the start of light emission by the light emitting unit 161, for example, and continued for a predetermined time after the light emission by the light emitting unit 161 is stopped.

The current input/output unit 20 outputs a current to the light source of the light emitting unit 161, and causes the light source to emit light with an appropriate amount of light. The current input/output unit 20 includes a circuit unit 220, and the circuit unit 220 serves as a power supply path for outputting a current. The CPU11 and the current input/output unit 20 constitute a current output circuit 200 of the present embodiment.

Fig. 2 is a diagram illustrating a circuit configuration of the current output circuit 200.

The current output circuit 200 includes current input/output units 20 (a plurality of control units 210 and a plurality of circuit units 220), and the current input/output units 20 are provided for the respective light sources, i.e., the R-LEDs and the B-LDs. The plurality of current input/output units 20 may have the same configuration, and here, only one current input/output unit 20 will be described. The current input/output unit 20 is divided into the control unit 210 and the circuit unit 220. The control section 210 has a DAC211 (Digital analog Converter) and a driver IC212. The circuit unit 220 includes a second switching element 22 (second switching unit), an inductor 23, a diode 24, a current measuring unit 25, a resistance element 26, a capacitor 27, a voltage measuring unit 28, a first switching element 29 (first switching unit), and the like.

The DAC211 acquires current-voltage setting data corresponding to the light amount setting 122 and the like from the CPU11, and outputs the current-voltage setting data as a comparison voltage and the like.

The driver IC212 receives a control signal for the presence or absence of light emission from the light source from the CPU11, and switches the presence or absence of output of the current by the first switching element 29. The switching of the current output (presence or absence of light emission from the light source) when the presence or absence of image projection is performed periodically. The driver IC212 performs duty drive, for example, PWM (Pulse Width Modulation) operation, for turning on/off (switching operation of opening/closing) the second switching element 22 based on the measurement data of the current measuring unit 25 and the voltage measuring unit 28. The CPU11 and the control unit 210, particularly the driver IC212 constitute the control unit of the present embodiment.

The second switching element 22 switches whether or not the power is supplied from an external power source or a power supply source such as a battery. The second switching element 22 includes, for example, an FET, and performs switching operations related to boosting of the input voltage and the like.

The inductor 23 accumulates and discharges electric energy in accordance with on/off change of current caused by the operation of the second switching element 22, thereby boosting and outputting the input voltage Vin. That is, the boosting operation is performed by the combination of the second switching element 22 and the inductor 23. The boosted voltage becomes a voltage suitable for driving a light source such as a B-LD.

The diode 24 is an element for preventing a reverse flow of an input current (power). The resistance element 26 appropriately adjusts the amount of current to suppress the generation of overcurrent.

The current measuring unit 25 measures the magnitude of the current flowing through the current input/output unit 20 (circuit unit 220) and outputs the measured current to the driver IC212. Since the current measuring unit 25 includes a minute resistance element, the resistance element 26 may not be included when the resistance value in the current input/output unit 20 is sufficient.

The capacitor 27 holds the input power (charge) and stabilizes the output voltage. Therefore, the capacity of the capacitor 27 is not excessively small compared to the output power. One end of the capacitor 27 is connected to a position closer to the current input side than the first switching element 29, and the other end opposite to the one end is connected to the ground plane. Here, the capacitor 27 includes two capacitors 27a and 27b arranged in parallel, but the number is not particularly limited. The other end of the capacitor 27 may be connected to a predetermined reference voltage plane without being grounded.

The voltage measuring section 28 measures the voltage of the capacitor 27 and outputs it to the driver IC212 and the CPU11.

The first switching element 29 is opened and closed by a drive signal from the driver IC212, and switches whether or not the current output from the current output circuit to the light source of the light emitting section 161 is present. The first switching element 29 is not particularly limited, but may be an analog element, here, a MOSFET.

Next, the light emission operation and the operation of the current output circuit 200 will be described.

The light source of the light emitting section 161 is an R-LED or a B-LD as described above, and can obtain light emission intensity corresponding to the current intensity. The current output circuit 200 performs control (constant current control) so as to output at a constant current when light is emitted. The overall light amount is increased or decreased by duty driving (for example, PWM control as described above). At this time, the duty driving is performed by the intermittent opening and closing of the second switching element 22 in a state where the first switching element 29 is on.

The light of each color of RYGB emitted from the light exit port is output in a time-sharing manner. The R-LEDs are turned on when each color R, Y is emitted, and turned off when each color G, B is emitted. The B-LD is turned on when the YGB colors are emitted, and turned off when the red (R) color is emitted. Upon the emission of green (G), the light of the B-LD is reflected by the fluorescent plate rotated by the rotation motor 164. The lighting period in this time division is much longer than the period of the duty drive.

While the light source to be current-output is turned off by the time-sharing control, the first switching element 29 is turned off. During this time, when the second switching element 22 is also turned off, the capacitor 27 enters self-discharge. After that, when the second switching element 22 is turned on again to charge the capacitor 27, the capacitor 27 is rapidly deformed to cause a ringing sound. In the light source device 1, while the light source is turned off and no current is output, the second switching element 22 is operated (the capacitor 27 is controlled to have a constant voltage) so that the capacitor 27 is maintained at the constant voltage. Since the discharge current of the capacitor 27 and the power consumption of the resistance element are much smaller than the current consumption at the time of lighting, the opening and closing operation of the second switching element 22 is performed at a lower duty ratio than at the time of lighting.

Fig. 3 is a diagram illustrating an input/output pattern of current.

In the uppermost layer, switching of the emission color with respect to the time axis is shown. As described above, the emission colors are periodically switched in the order of R, Y, G, B every cycle. The period is the length of the switching that the viewer of the projected image cannot visually recognize. The above-described period may be different for each color, and may be different in length between colors depending on human vision and the like.

In order to perform the time-sharing control of the emitted light as described above, the output of the blue-light-emitting LD (B-LD) is turned on when Y, G, B is emitted and turned off when R is emitted, as described above. During the emission period, the current output circuit 200 performs constant current control, and the input of the current is switched at a high duty ratio. During the injection stop period, the current output circuit 200 performs constant voltage control. During this period, since there is no output of the B-LD, the power consumption is reduced accordingly, and therefore the input of the current is switched at a low duty ratio.

Here, the output voltage Vc that is the voltage of the capacitor 27 is maintained at the same constant voltage as the voltage at the time of constant current control, and a voltage drop at the time of stopping the injection and a sharp voltage rise at the time of restarting the injection do not occur as in the conventional case shown by the broken line. This suppresses the occurrence of a squealing noise associated with rapid deformation of the capacitor 27. The output voltage Vc during the constant current control is obtained by measurement by the voltage measuring unit 28.

As described above, the output of the R-LED is turned on when R, Y is emitted, and turned off when G, B is emitted. During the injection period, the current output circuit 200 performs a constant current operation, and the input of the current is switched at a high duty ratio. During the injection stop period, the current output circuit 200 performs a constant voltage operation. During this time, since there is no output of the R-LED and the power consumption is reduced accordingly, the input of the current is switched at a low duty ratio.

In this case as well, similarly to B-LD, the voltage drop at the time of stop of the injection as shown by the broken line is suppressed, and thereby the ringing sound caused by the deformation of the capacitor 27 is also suppressed.

Fig. 4 is a flowchart showing a control procedure by the CPU11 (control unit) of the current input/output control process executed in the light source device 1 as the control method of the current output circuit according to the present embodiment. The input/output control process is started when the lighting operation of the light source of the light emitting unit 161 is started, and is continuously executed. The input/output control process may be executed in parallel for each of the plurality of light sources (R-LED, B-LD).

When the input/output control process is started, the CPU11 determines whether or not the light source is the first lighting period of the time-sharing light source (step S101). If it is determined that the lighting time is not the first lighting time of the light source (no in step S101), the CPU11 repeats the process of step S101.

When it is determined that the lighting period is the first lighting period of the light source (yes in step S101), the CPU11 outputs a control signal for turning on the first switching element 29 on the output side to the driver IC212 (step S102). The CPU11 starts the constant current control by the driver IC212 and performs the opening and closing operation of the second switching element 22 on the input side (step S103). Thereby, the driver IC212 starts the constant current control of the circuit section 220. The CPU11 obtains the output voltage during the constant current control from the voltage measuring unit 28 (step S104). After that, the CPU11 proceeds to step S110.

When the process proceeds to step S110, the CPU11 determines whether or not the switching timing of the lighting-off period in the time-sharing control is reached (step S110). If it is determined that the lighting-off period is not the switching timing (no in step S110), the CPU11 repeats the process of step S110.

When it is determined that the switching timing is the lighting-off period (yes in step S110), the CPU11 determines whether the switched period is the lighting period (step S110). If it is determined that the lighting period is present (yes in step S111), the CPU11 proceeds to step S102.

When it is determined that the switched period is not the lighting period (is the turning-off period) (no in step S111), the CPU11 outputs a control signal for turning off the first switching element 29 on the output side to the driver IC212 (step S121). The CPU11 starts the constant voltage control by the driver IC212 so that the voltage value obtained in the process of step S104 is obtained, and opens and closes the second switching element 22 on the input side (step S122). Thereby, the driver IC212 starts the constant voltage control of the circuit portion 220. Then, the CPU11 returns the process to step S110.

The processing of steps S102 and S121 constitutes a first switching step (first switching means) of the present embodiment, and steps S103 and S122 constitute a second switching step (second switching means) of the present embodiment.

As described above, the current output circuit 200 of the present embodiment includes the circuit unit 220, and the CPU11 and the driver IC212 (control unit 210) as the control unit, and the circuit unit 220 includes: a first switching element 29 that switches whether or not to output a current to a light source that is a destination of power supply; a second switching element 22 that switches whether or not energization from an external power source or the like, which is a power supply source; and a capacitor 27 connected to the first switching element 29 and the second switching element 22. The driver IC212 instructs the first switching element 29 to periodically switch the presence or absence of current output based on the control of the CPU11, and instructs the second switching element 22 to conduct current to the power supply source by a switching operation having a duty ratio smaller than that in the case where current output is performed by the first switching element 29 when current output is not performed by the first switching element 29. The change in duty ratio includes a change in duty ratio due to an increase or decrease in power consumption by a supply destination (light source) of current or the like.

By continuing the supply of current to capacitor 27 while reducing the voltage drop due to self-discharge of capacitor 27, the deformation of capacitor 27 caused by the voltage drop can be reduced. Therefore, in the current output circuit 200, the ringing sound according to the deformation accompanying the recharging when the current output is restarted can be reduced. In particular, in the case where a plurality of capacitors 27 for the same purpose are charged and discharged simultaneously, that is, deformed, it is difficult to reduce the sound by taking a mental effort in arranging the capacitors 27, and therefore, by reducing the deformation itself in this way, the sound due to periodic charging and discharging can be reduced.

The control unit (CPU 11 and/or driver IC 212) performs constant current control of the current output from the current input/output unit 20 (circuit unit 220) by the operation of the second switching element 22 while the current is output by the first switching element 29, and performs constant voltage control of the capacitor 27 by the operation of the second switching element 22 while the current is not output by the first switching element 29.

This can appropriately reduce the deformation of the capacitor 27, and thus can effectively reduce the ringing sound associated with the deformation.

The constant current control and the constant voltage control are performed by PWM control for opening and closing the second switching element 22. Since PWM control can be performed at high speed and with high accuracy with low power consumption and with little power loss, it is possible to control the current and voltage while appropriately reducing unnecessary voltage and current fluctuation.

The current output circuit 200 includes a voltage measuring unit 28 that measures the voltage of the capacitor 27. The control unit obtains the voltage at the time of constant current control from the voltage measuring unit 28, and performs constant voltage control by the second switching element 22 using the obtained voltage.

This makes it possible to prevent the voltage from changing substantially during the constant current control and the constant voltage control, and thus deformation of the capacitor 27 can be effectively suppressed, and ringing can be effectively suppressed.

The current output circuit 200 includes a plurality of circuit units 220. The control unit determines the period during which the current is output by the first switching element 29 in each of the plurality of circuit units 220. That is, the current input/output unit 20 having the circuit unit 220 is preferably a current output circuit 200 for causing light sources of a plurality of wavelengths to perform an on/off operation, respectively, in order to output a multicolor color by time division. Even when a plurality of sets of capacitors 27 are provided and operated individually as described above, it is difficult to suppress vibration of the entire substrate due to the positional relationship of the plurality of capacitors 27, and therefore, in the current output circuit 200, by reducing the deformation of the capacitors 27, it is possible to suppress ringing.

The light source device 1 of the present embodiment includes the current output circuit 200 described above and a light source including a light emitting unit 161 that emits light in accordance with the current output by the current output circuit 200. According to the light source device 1, unnecessary ringing sound is suppressed at the time of exhibition or the like using the light source device 1, and light corresponding to a desired image or the like can be emitted while operating quietly.

In addition, the method for controlling a current output circuit according to the present embodiment includes: a first switching step of instructing the first switching element 29 to periodically switch the presence or absence of output of a current to the light source as a power supply destination; and a second switching step of, when the current output to the light source is not performed by the first switching element 29, instructing the second switching element 22 to perform a switching operation at a duty ratio smaller than that in a case where the current output to the light source is performed by the first switching element 29, thereby causing the current to flow between the external power supply or the like, which is a power supply source. With such a method of controlling the current output circuit, in a circuit in which the current output is intermittently switched, the charging and discharging of the capacitor 27, particularly a ceramic capacitor having a large conductivity, which stores electric power between the first switching element 29 and the second switching element 22, can be suppressed, and the distortion accompanying the charging and discharging can be reduced, thereby reducing the ringing of the capacitor.

The program 121 of the present embodiment causes a computer provided with the CPU11 to function as a first switching means for instructing the first switching element 29 whether or not to switch the output of the current to the light source, and a second switching means for instructing the second switching element 22 to perform a switching operation with a duty ratio smaller than that in the case where the output of the current to the light source is performed by the first switching element 29, so as to allow the power to be supplied to the external power source, which is the power supply source, when the output of the current to the light source is not performed by the first switching element 29.

By installing and executing the program 121, the sound of the capacitor can be appropriately reduced without adding or changing the hardware configuration.

The present invention is not limited to the above embodiment, and various modifications are possible.

For example, in the above-described embodiment, the case where the voltage value is acquired during the constant current control and the constant voltage control is performed using the acquired voltage value has been described, but the present invention is not limited thereto. The voltage value of the constant voltage control may also be predetermined. Alternatively, instead of actively performing the constant voltage control, the PWM control may be performed by determining a duty ratio to be a substantially constant voltage in advance. That is, the voltage may be reduced to a level at least capable of suppressing the ringing sound. In this case, when the current output is not performed, the voltage may be increased as compared with the case of performing the current output. The voltage rise range may be set to a voltage rise range smaller than the voltage drop range in the case where the second switching element 22 is completely turned off, without generating an overvoltage or excessive deformation of the capacitor 27 (excessive stress to the substrate or a bonding member to the substrate) accompanying the overvoltage or an overcurrent to the light source when the current output is restarted.

In the above embodiment, the duty ratio is changed by PWM control while keeping the operation interval of turning on the second switching element 22 constant during duty drive, but the duty ratio may be changed by changing the on interval while fixing the current (power) input time (the time of turning on the second switching element 22).

In the above embodiment, the case where the CPU11 collectively controls the current output periods of the plurality of current input/output units 20 (circuit units 220), that is, the light emission periods of the light sources has been described, but the CPU alone may independently control the current output periods. The timing control may be independent control or may be synchronized with each other based on setting data, a synchronization signal, or the like.

In the above-described embodiment, the case where two light sources, i.e., the R-LED and the B-LD, are provided has been described, but the present invention is not limited thereto. There may be 3 or more light sources, or only 1 light source.

In the above embodiment, the current output circuit 200 that outputs a current to the light source of the light source device 1 as the projection device is described as an example, but the present invention is not limited thereto. The light source may be not a projection device but a device for outputting other light signals or the like. The current output circuit 200 may be used not for the light source device 1 but for other electronic devices, for example, a device that performs intensity change of continuous operation such as motor operation, sound output, and heating (heat generation) operation by duty drive. Further, control of current output to the light source and control of current output to another load may be combined.

In the above-described embodiment, the CPU11 executes the program 121 to control the input and output of the current, but in this case, the CPU11 may perform all the control operations and the driver IC212 may simply output only the voltage corresponding to the drive signal. On the contrary, the control operation may be performed by a microcomputer or the like instead of the control operation of the CPU11, and the light source device 1 may have a dedicated hardware circuit for performing current input/output control.

In the above description, the ROM12 configured by a mask ROM, a nonvolatile memory such as a flash memory, or the like is used as an example of a computer-readable medium storing the program 121 for current input/output control according to the present invention, but the present invention is not limited thereto. Other computer-readable media include other nonvolatile memories such as MRAM and other portable recording media (non-transitory computer-readable recording media) such as HDD, CD-ROM, and DVD disk. In addition, as a medium to which data of the program of the present invention is supplied via a communication line, carrier wave (carrier wave) is also applicable to the present invention.

The specific configurations, contents of processing operations, steps, and the like shown in the above embodiments can be modified as appropriate without departing from the scope of the present invention.

Although the embodiments of the present invention have been described, the scope of the present invention is not limited to the above embodiments, and includes the scope of the invention described in the claims and the equivalent scope thereof.

Hereinafter, the invention described in the claims attached at the beginning is attached to the application of the present application. The reference numerals of the technical means described in the attached drawings are as described in the claims attached to the first of the specification of the present application.

Claims (8)

1. A current output circuit is characterized in that,

comprises a circuit part and a control part, wherein,

the circuit unit includes:

a first switching unit for switching the output of current;

a second switching unit that switches whether or not power is supplied from a power supply source; and

a capacitor connected to the first switching part and the second switching part,

the control part is used for controlling the operation of the motor,

instructing the first switching section to periodically switch the presence or absence of the output,

when the output is not performed by the first switching unit, the second switching unit is instructed to perform a switching operation at a duty ratio smaller than that in a case where the output is performed by the first switching unit, thereby causing the current to flow between the second switching unit and the supply source.

2. The current output circuit of claim 1,

the control unit performs constant current control of the output by the operation of the second switching unit while the output is performed by the first switching unit, and performs constant voltage control of the capacitor by the operation of the second switching unit while the output is not performed by the first switching unit.

3. The current output circuit of claim 2,

the constant current control and the constant voltage control are performed by pulse width modulation control for opening and closing the second switching unit.

4. Current output circuit according to claim 2 or 3,

a voltage measuring unit for measuring the voltage of the capacitor,

the control unit obtains the voltage at the time of the constant current control from the voltage measuring unit, and performs the constant voltage control by the second switching unit using the obtained voltage.

5. The current output circuit according to any one of claims 1 to 4,

the circuit device is provided with a plurality of circuit parts,

the control unit determines a period during which the output is performed by the first switching unit in each of the plurality of circuit units.

6. A light source device is characterized by comprising:

a current output circuit according to any one of claims 1 to 5; and

and a light source unit for emitting light in accordance with the current output from the current output circuit.

7. A control method of a current output circuit, the current output circuit using: a first switching unit for switching the output of current; a second switching unit that switches whether or not power is supplied from a power supply source; and a capacitor connected to the first switching unit and the second switching unit, wherein the method for controlling the current output circuit includes:

a first switching step of instructing the first switching unit to periodically switch the presence or absence of the output; and

a second switching step of instructing the second switching unit to perform a switching operation with a duty ratio smaller than that in a case where the output is not performed by the first switching unit, and to cause the power supply to be supplied to the supply source.

8. A non-transitory computer-readable recording medium having a program recorded thereon, the program causing a computer to function as a first switching means and a second switching means,

the computer operates a circuit unit, the circuit unit including: a first switching unit for switching the output of current; a second switching unit that switches whether or not power is supplied from a power supply source; and a capacitor connected to the first switching portion and the second switching portion,

the first switching unit instructs the first switching unit to switch the output,

the second switching unit instructs the second switching unit to perform a switching operation with a duty ratio smaller than that in a case where the output is not performed by the first switching unit, and to cause the supply source to be energized.

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