Abstract: An error amplifier amplifies the difference between a first detection voltage VR at a first detection resistor on a path of a driving current ILED and a dimming control signal VDIM that corresponds to the target luminance level of a light emitting element. A pulse width modulator generates a gate pulse signal according to an output VFB of the error amplifier. M comparators each assert an overcurrent detection signal when a corresponding detection voltages VR1 or VR2 that corresponds to voltage drop across detection resistors R1 or R2 exceeds a corresponding threshold voltage VTH1 or VTH2. Of the threshold voltages VTH1 and VTH2, at least one is set (i) to increase as the dimming control signal VDIM increases when the dimming control signal VDIM exceeds a predetermined first value, and (ii) to a predetermined lower limit value when the dimming control signal VDIM is lower than the first value.

Abstract: A display apparatus includes: a cylindrical casing which is rotatably driven; and a plurality of curve-arranged displays which are installed inside the casing and have the same number as a plurality of slits formed in the casing, wherein each curve-arranged display has an L-shaped or inverted L-shaped cross-section, and short sides of a plurality of display device substrates in which a display device is installed on the short side of the L shape or the inverted L shape are arranged in the form of an arc.

Abstract: A current driving circuit is connected to an LED terminal LEDi, and generates an intermittent driving current ILEDi that corresponds to a dimming pulse signal PWMi. An error amplifier generates a feedback voltage VFB that corresponds to the difference between a detection voltage VLEDi and a predetermined reference voltage VREF. A pulse modulator generates a pulse signal having a duty ratio that corresponds to the feedback voltage VFB. A fault detection comparator COMP_OPENi generates a fault detection signal OPEN_DET which is asserted when the detection voltage VLEDi is lower than a predetermined threshold voltage VOPEN—DET. A forced turn-off circuit instructs the current driving circuit to suspend the generation of the driving current ILEDi during a predetermined period after a switching power supply starts to operate. The fault detection circuit detects whether or not the fault detection signal OPEN_DETi has been asserted in a predetermined period.

Abstract: A current generating circuit may include a first current source configured to generate a first current having positive temperature characteristics; a second current source configured to generate a second current; a compensation transistor configured as an NPN bipolar transistor, and arranged such that the second current flows through from its collector and its emitter; and a first current mirror circuit configured to multiply a base current of the compensation transistor by a first coefficient so as to generate a third current. The current generating circuit may be configured to output a fourth current that is proportional to the difference between the first current and the third current.

Abstract: A display apparatus includes: a cylindrical casing which is rotatably driven; and a plurality of curve-arranged displays which are installed inside the casing and have the same number as a plurality of slits formed in the casing, wherein the curve-arranged displays include a light housing which is an approximately semi-cylindrical column having a hollow structure, and a plurality of display device substrates installed on an arc-shaped side surface of the approximately semi-cylindrical column of the light housing.

Abstract: A current driving circuit may include a reference voltage input terminal; a resistor connection terminal; an output terminal via which the light emitting element is connected; a reference voltage generating unit; a transistor arranged such that one terminal thereof is connected to the resistor connection terminal; and an operational amplifier including first and second non-inverting input terminals and a single inverting input terminal, and arranged such that the output terminal thereof is connected to a control terminal of the transistor, the internal reference voltage is input to the first non-inverting input terminal, the external reference voltage is input to the second non-inverting input terminal, and the inverting input terminal thereof is connected to the resistor connection terminal. When the external resistor is connected between the resistor connection terminal and a ground terminal, a driving current is output via the output terminal.

Abstract: A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.

Abstract: A comparator compares a first input voltage and a second input voltage to generate a comparative output depending on a result of the comparison. The comparator includes a first input terminal configured to receive the first input voltage, a second input terminal configured to receive the second input voltage, a differential pair including a first input transistor whose control terminal is connected with the first input terminal and a second input transistor whose control terminal is connected with the second input terminal, a tail current source configured to supply a tail current to the differential pair, and a load circuit connected to the first input transistor and the second input transistor, and the tail current source increases the tail current, as the first input voltage approaches the second input voltage, depending on the first input voltage.

Abstract: A control IC controls a switching power supply configured to supply a driving voltage Vout to one terminal of an LED string to be intermittently driven. In the on period of the LED string, a pulse modulator generates a pulse signal having a duty ratio adjusted such that a detection voltage VLED that corresponds to the output voltage Vout of the switching power supply matches a predetermined reference voltage Vref. A driver drives a switching transistor included in the switching power supply according to the pulse signal. After transition from the on period to the off period, the pulse modulator reduces the duty ratio of the pulse signal over time.

Abstract: A soft-start circuit generates a soft-start voltage Vss having a voltage level that rises over time. A pulse width modulator generates a PWM signal having a duty ratio adjusted such that a feedback voltage Vout? that corresponds to the output voltage Vout of the switching power supply matches the soft-start voltage Vss. A driver circuit controls a switching element according to the PWM signal. A capacitor is arranged such that one terminal thereof is set to a fixed electric potential. A current source generates a charge current that flows intermittently in synchronization with the PWM signal so as to charge the capacitor. The soft-start circuit outputs, as the soft-start voltage Vss, a voltage that occurs at the capacitor.

Abstract: A display apparatus includes: a cylindrical casing which is rotatably driven; and a plurality of curve-arranged displays which are installed inside the casing and have the same number as a plurality of slits formed in the casing, wherein the curve-arranged displays include a light housing which is an approximately semi-cylindrical column having a hollow structure, and a plurality of display device substrates installed on an arc-shaped side surface of the approximately semi-cylindrical column of the light housing.

Abstract: Provided is a display device including a housing whose side surface has one or more slits, and a display that is mounted in the housing and has a substantially arc shape, wherein an image displayed on the display is visually recognized beyond the slit when the housing rotates, and a curvature of the display having the substantially arc shape is formed so that stray light resulting from a specular reflection does not occur.

Abstract: A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.

Abstract: A first current source generates a first current having positive temperature characteristics. A second current source generates a second current. A first current mirror circuit generates a third current by multiplying, by a first coefficient, the base current of a compensation transistor configured as an NPN bipolar transistor arranged on a path of the second current. A second current mirror circuit generates a fourth current that is proportional to the difference between the first current and the third current. A current generating circuit outputs the sum total of the fourth current and a fifth current that is proportional to the base current.

Abstract: A control IC controls a switching power supply configured to supply a driving voltage Vout to one terminal of an LED string to be intermittently driven. In the on period of the LED string, a pulse modulator generates a pulse signal having a duty ratio adjusted such that a detection voltage VLED that corresponds to the output voltage Vout of the switching power supply matches a predetermined reference voltage Vref. A driver drives a switching transistor included in the switching power supply according to the pulse signal. After transition from the on period to the off period, the pulse modulator reduces the duty ratio of the pulse signal over time.

Abstract: A power supply unit, adapted to provide a predetermined output voltage from its output circuit, compares a feedback voltage associated with the output voltage of the output circuit with a reference voltage so as to control the output circuit. The power supply unit is enabled and disabled in response to an externally supplied operation command signal. The reference voltage is generated by a reference voltage generation circuit, which is operable on the voltage of the operation command signal, and is controllably enabled when the voltage of the operation command signal exceeds a predetermined level, but otherwise disabled. Thus, the reference voltage is stabilized to improve the ripple rejection characteristic of the power supply unit without increasing its current consumption.

Abstract: A current mirror circuit duplicates an input current that flows through an input terminal, and outputs an output current via an output terminal. A first transistor, a second transistor, and a diode are sequentially arranged in series between a power supply terminal to which a fixed voltage is applied and an input terminal. A third transistor and a fourth transistor are sequentially arranged in series between the power supply terminal and the output terminal. The gate of the first transistor and the gate of the third transistor are connected to the drain of the second transistor. The gate of the second transistor and the gate of the fourth transistor are connected to the input terminal.

Abstract: A light emitting device includes: a light emitting chip arranged on a substrate; a resin lens which covers the light emitting chip and focuses irradiation light from the light emitting chip; a mask which covers a region of an upper layer surface of the substrate, other than the resin lens; and a low surface tension film formed on a region of the upper layer surface of the substrate, other than in the proximity of the light emitting chip.

Abstract: A light emitting device includes: a light emitting chip arranged on a substrate; and a resin lens formed to cover the light emitting chip, wherein the center of the light emitting chip and the center of the resin lens are offset so that the centers do not match each other.

Abstract: A display apparatus includes: a cylindrical casing which is rotatably driven; and a plurality of curve-arranged displays which are installed inside the casing and have the same number as a plurality of slits formed in the casing, wherein the curve-arranged displays include a light housing which is an approximately semi-cylindrical column having a hollow structure, and a plurality of display device substrates installed on an arc-shaped side surface of the approximately semi-cylindrical column of the light housing.