Electronic device and display device
According to one embodiment, an electronic device includes a circuit board and a circuit component on an upper surface or a lower surface of the circuit board. The circuit component includes a first ceramic capacitor and a second ceramic capacitor. Vibration characteristics of the first ceramic capacitor and a second ceramic capacitor are opposed to each other. The first ceramic capacitor is near the second ceramic capacitor to cause vibrations of the first and second ceramic capacitors to cancel each other.
1. A display device, comprising: a two-dimensional pixel array;
a backlight under the pixel array; and
a drive circuit configured to drive the backlight,
wherein the drive circuit comprises a step-up circuit configured to step up an input voltage,
the step-up circuit comprises at least one first ceramic capacitor electrically connected to an input side and at least one second ceramic capacitor electrically connected to an output side,
the at least one first ceramic capacitor is near the at least one second ceramic capacitor to cause vibrations of the at least one first ceramic capacitor and the at least one second ceramic capacitor to cancel each other.
2. An electronic device comprising:
a circuit board; and
a circuit component on an upper surface or a lower surface of the circuit board, wherein
the circuit component comprises a first ceramic capacitor and a second ceramic capacitor,
vibration characteristics of the first ceramic capacitor and a second ceramic capacitor are opposed to each other,
the first ceramic capacitor is near the second ceramic capacitor to cause vibrations of the first and second ceramic capacitors to cancel each other,
the first ceramic capacitor comprises first capacitors, the second ceramic capacitor comprises second capacitors, and
the first capacitors and the second capacitors are arranged alternately.
3. The electronic device of claim 2 , wherein
each of the first capacitors and each of the second capacitors are arranged alternately.
4. The electronic device of claim 2 , wherein
each of the first capacitors and each of the second capacitors are arranged alternately in column and row directions.
5. An electronic device comprising:
a circuit board; and
a circuit component on an upper surface or a lower surface of the circuit board,
wherein
the circuit component comprises a first ceramic capacitor and a second ceramic capacitor,
vibration characteristics of the first ceramic capacitor and a second ceramic capacitor are opposed to each other,
the first ceramic capacitor is near the second ceramic capacitor to cause vibrations of the first and second ceramic capacitors to cancel each other,
the first ceramic capacitor comprises first capacitors,
the second ceramic capacitor comprises second capacitors,
an amplitude of the vibration of the first ceramic capacitor is different from an amplitude of the vibration of the second ceramic capacitor, and
number corresponding to the amplitude of the vibration of the second ceramic capacitor, of the first capacitors and number corresponding to the amplitude of the vibration of the first ceramic capacitor, of the second capacitors, are arranged alternately.
6. The electronic device of claim 5 , wherein
the first capacitors and the second capacitors are arranged alternately in the column and row directions.
7. An electronic device comprising,
a circuit board; and
a circuit component on an upper surface or a lower surface of the circuit board,
wherein
the circuit component comprises a first ceramic capacitor and a second ceramic capacitor,
vibration characteristics of the first ceramic capacitor and a second ceramic capacitor are opposed to each other,
the first ceramic capacitor is near the second ceramic capacitor to cause vibrations of the first and second ceramic capacitors to cancel each other,
the circuit component further comprises a first component of a step-up circuit configured to step up an input voltage to a predetermined voltage,
the first ceramic capacitor comprises a capacitor electrically connected to an input side of the step-up circuit, and
the second ceramic capacitor comprises a capacitor electrically connected to an output side of the step-up circuit.
8. The electronic device of claim 7 , wherein
the circuit component further comprises a second component of a driving circuit configured to drive a light-emitting diode with the predetermined voltage and a third component of a switch control circuit configured to operate or stop the step-up circuit based on a dimming signal.
9. The electronic device of claim 8 , wherein
the dimming signal comprises a binary rectangular wave having a frequency of 1 kHz or less.
10. The electronic device of claim 7 , wherein
the step-up circuit comprises a switching regulator or a three-terminal regulator.
11. An electronic device comprising:
a circuit board; and
a circuit component on an upper surface or a lower surface of the circuit board,
wherein
the circuit component comprises a first ceramic capacitor and a second ceramic capacitor,
vibration characteristics of the first ceramic capacitor and a second ceramic capacitor are opposed to each other,
the first ceramic capacitor is near the second ceramic capacitor to cause vibrations of the first and second ceramic capacitors to cancel each other, and
a power source voltage applied to the first ceramic capacitor is applied to the second ceramic capacitor via an inverting circuit.
12. The electronic device of claim 11 , wherein
the inverting circuit comprises an operational amplifier,
a voltage is applied to an inverted input terminal of the operational amplifier via an input resistor, and
half of the power source voltage is applied to a non-inverted input terminal of the operational amplifier.
13. An electronic device, comprising:
a circuit board; and
a circuit component on an upper surface or a lower surface of the circuit board,
wherein
the circuit component comprises a first ceramic capacitor and a second ceramic capacitor,
each of the first ceramic capacitor and the second ceramic capacitor comprises a pair of external electrodes,
the first ceramic capacitor and the second ceramic capacitor are arranged adjacent to each other wherein the pair of external electrodes are arranged in a same direction,
a first alternating voltage is applied to the pair of external electrodes of the first ceramic capacitor,
a second alternating voltage is applied to the pair of external electrodes of the second ceramic capacitor, and
a phase of the first alternating voltage is opposite to a phase of the second alternating voltage.
14. The electronic device of claim 13 , wherein
each of the first ceramic capacitor and the second ceramic capacitor comprises internal electrodes layered alternately with ceramic dielectric; and the pair of the external electrodes is connected to the internal electrodes and on both sides of the first ceramic capacitor and the second ceramic capacitor.