Light source modulation circuit, light source modulation method, and projector apparatus
View Patent ↗A light source modulation circuit includes a pulse width modulator (PWM) PWM-modulating an input PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal, a frequency divider circuit frequency-dividing the PWM carrier signal at a predetermined frequency division ratio to output a communication carrier signal, a communication modulator modulating the communication carrier signal according to an input communication modulation code to output a communication modulation signal, an operational circuit performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal, and a light source drive circuit generating a light source drive signal based on the light source modulation signal.
1. A light source modulation circuit comprising:
a pulse width modulator (PWM) PWM-modulating an input PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal;
a frequency divider circuit frequency-dividing the PWM carrier signal at a predetermined frequency division ratio to output a communication carrier signal;
a communication modulator modulating the communication carrier signal according to an input communication modulation code to output a communication modulation signal;
an operational circuit performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal; and
a light source drive circuit generating a light source drive signal based on the light source modulation signal, wherein
the communication modulator outputs the communication modulation signal to the operational circuit.
2. A projector apparatus comprising the light source modulation circuit according to claim 1 .
3. A light source modulation circuit comprising:
a communication modulator modulating an input communication carrier signal according to an input communication modulation code to output a communication modulation signal;
a multiplying circuit multiplying the communication carrier signal by a predetermined multiplication number to output a PWM carrier signal;
a PWM PWM-modulating the PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal;
an operational circuit performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal; and
a light source drive circuit generating a light source drive signal based on the light source modulation signal, wherein
the communication modulator outputs the communication modulation signal to the operational circuit.
4. A projector apparatus comprising the light source modulation circuit according to claim 3 .
5. A light source modulation method comprising the steps of:
PWM-modulating an input PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal;
frequency-dividing the PWM carrier signal at a predetermined frequency division ratio to output a communication carrier signal;
modulating the communication carrier signal according to an input communication modulation code to output a communication modulation signal;
performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal;
generating a light source drive signal based on the light source modulation signal; and
outputting the communication modulation signal for the step of performing the logical AND operation of the PWM-modulated signal and the communication modulation signal.
6. A light source modulation method comprising the steps of:
modulating an input communication carrier signal according to an input communication modulation code to output a communication modulation signal;
multiplying the communication carrier signal by a predetermined multiplication number to output a PWM carrier signal;
PWM-modulating the PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal;
performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal;
generating a light source drive signal based on the light source modulation signal; and
outputting the communication modulation signal for the step of performing the logical AND operation of the PWM-modulated signal and the communication modulation signal.
7. The projector apparatus according to claim 2 , wherein
the input communication modulation code is generated in response to a projected image projected by the projector apparatus.
8. The projector apparatus according to claim 2 , wherein
the input communication modulation code superposes a timing of light generated by the light source modulation circuit on a timing of an image signal of a projected image.
9. The projector apparatus according to claim 4 , wherein
the input communication modulation code is generated in response to a projected image projected by the projector apparatus.
10. The projector apparatus according to claim 4 , wherein
the input communication modulation code superposes a timing of light generated by the light source modulation circuit on a timing of an image signal of a projected image.
11. The light source modulation method according to claim 5 , wherein
the input communication modulation code is generated in response to a projected image projected by the projector apparatus.
12. The light source modulation method according to claim 5 , wherein
the input communication modulation code superposes a timing of light generated by the light source modulation circuit on a timing of an image signal of a projected image.