Monolithic optical read-out circuit

• US 20040198463A1
• Filed: 02/10/2003
• Published: 10/07/2004
• Est. Priority Date: 02/06/2003
• Status: Active Grant

• Current Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Original Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Inventors: Knoedgen, Horst
• Granted Patent: US 7,260,422 B2
• Time in Patent Office: Days
• US Class Current: 455/569.1
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: H04M 1/605 involving control of the receiver volume to provide a dual operational mode at close or far distance from the user
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion telephones including GPS signal receivers H04M2250/10
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A circuit and method are given, to realize a loudness control for mobile phone earpieces and speakers with the help of a proximity sensor, which is realized as an infrared photo-electric guard circuit, where only very few external parts are needed. As a novelty here, the necessary photo sensors are integrated onto a single chip. To form the photodiodes within a single IC together with the other circuit elements are much less expensive. Using the advantages of that solution the circuit of the invention is manufactured with standard CMOS technology and only very few discrete external components. This solution reduces also power consumption and manufacturing cost.

Claims

1. A method for realizing a loudness control of an earpiece of a mobile phone in such a way, that unpleasant and harmful loudness levels are avoided for the user by exploiting an optical proximity sensing method, consisting of a photon generating device and photon sensing devices with a common control means also used for the loudness control of a loudspeaker system, comprising:

providing said loudspeaker system of said earpiece, said photon generating device, said photon sensing device, and said common control means;

starting the driving of said sound generating loudspeaker system and establish a secure threshold sound level within said common control means;

setting-up and driving said photon-generating device as primary photon source;

establishing and driving two different photon-sensing devices in two different photo channels;

measuring the distance from a reflective surface by comparing the photo input signals to said two different photo channels;

evaluating said photo input signals taking into account obnoxious side effects thus effectively compensating for said obnoxious side effects;

comparing said measured distance to the correspondingly equivalent of said established secure sound level threshold value;

deciding accordingly to the programmed logic implemented within said common control means with its primary goal, to reduce loudness if distance is small, i.e. phone close to ear; and

generating output signals according to the result of the decision, thus avoiding unpleasant and harmful loudness levels.

2. The method according to claim 1 wherein said step of setting-up and driving said photon generating device as primary photon source is implemented as a driving of said photon source with pulses.

3. The method according to claim 1 wherein said step of establishing and driving two different photon sensing devices in two different photo channels is used for accounting of temperature drift effects and ambient light effects and the like and the driving signals for said different photo channels are synchronized pulses.

4. The method according to claim 1 wherein said photon generating device is implemented as a light emitting diode (LED).

5. The method according to claim 1 wherein said photon sensing devices are implemented as photo diodes.

6. The method according to claim 1 wherein said step of measuring the distance from a reflective surface by comparing said photo input signals to said two photo channels is realized as comparing said photo input signals from periods, where said photon generating device is operating (ON/light) and periods, where said photon generating device is not operating (OFF/dark).

7. The method according to claim 1 wherein said reflective surface is the head of a user.

8. The method according to claim 1 wherein said obnoxious side effects include any effects such as temperature and/or ageing drift and/or ambient light effects.

9. A circuit, capable of controlling the loudness of an earpiece of a phone or the like in such a way, that unpleasant and harmful loudness levels are avoided for the user of the earpiece by exploiting an optical proximity sensing method, comprising:

means for generating photons having a photon control input;

means for sensing said photons having a photon signal output wherein measuring the intensity of said photons reflected from an object establishes said optical proximity sensing method thus determining the distance from circuit to object and generating a distance output signal proportional thereto at said photon signal output;

means for generating phonons having both a phonon signal and a phonon control input and wherein said phonon signal input receives external information signals additionally controlled by phonon control signals fed into said phonon control input by some means for common control of phonons and photons in such a way, that energy and intensity of the phonons are controlled subject to said distance output signal; and

said means for common control of phonons and photons controlling said means for generating photons, said means for sensing photons and said means for generating phonons having both phonon and photon control inputs and both phonon and photon control outputs wherein said phonon control input is appropriately fed from said phonon generating means and said photon control input is fed from said means for sensing photons and said photon control output is feeding said means for generating photons and said phonon control output is appropriately feeding said phonon generating means in such a way, that unpleasant and harmful loudness levels to the user are avoided.

10. The circuit according to claim 9 wherein said means for generating photons is a light emitting diode (LED).

11. The circuit according to claim 9 wherein said means for generating photons contains a driver circuit.

12. The circuit according to claim 9 wherein said means for sensing photons is a photo diode.

13. The circuit according to claim 9 wherein said means for sensing photons contains a photon receiver circuit.

14. The circuit according to claim 9 wherein said means for generating phonons is a loudspeaker in an earpiece.

15. The circuit according to claim 9 wherein said means for generating phonons contains an amplifier.

16. The circuit according to claim 9 wherein said means for common control is an integrated control circuit.

17. The circuit according to claim 9 manufactured in monolithic integrated circuit technology.

18. The circuit according to claim 9 wherein said object is the head of the user of the phone.

19. The circuit according to claim 17 manufactured in monolithic integrated CMOS technology.

20. The circuit according to claim 18 wherein said means for photon sensing is manufactured in N-well technology together with some kind of guard ring.

21. The circuit according to claim 18 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

22. A circuit, capable of detecting and sensing photons and generating an appropriate output signal having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

a photo diode connected to both the gate input of a field effect transistor and to one contact of a switching device;

said switching device also connected to said supply voltage;

said field effect transistor connected with its drain input to said supply voltage and connected with its source input to both a current source and a control circuit;

said current source also connected to ground; and

said control circuit generating said appropriate output signal of the circuit.

23. The circuit according to claim 22 representing an essential part of implementing a mobile phone to computer data link.

24. The circuit according to claim 22 representing an essential part of implementing a computer-to-computer data link.

25. The circuit according to claim 22 representing an essential part of implementing a computer to peripheral data link.

26. The circuit according to claim 22 representing an essential part of implementing a computer to television set data link.

27. The circuit according to claim 22 representing an essential part of implementing a data link with additional power regulation features.

28. The circuit according to claim 22 representing an essential part of implementing a radiation intensity measurement system.

29. The circuit according to claim 22 representing an essential part of implementing a reflection measurement system.

30. The circuit according to claim 22 representing an essential part of implementing a position detection system.

31. The circuit according to claim 22 representing an essential part of implementing a reflection measurement system with visible or invisible light spectra.

32. The circuit according to claim 22 manufactured in monolithic integrated circuit technology.

33. The circuit according to claim 32 manufactured in monolithic integrated CMOS technology.

34. The circuit according to claim 33 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

35. The circuit according to claim 33 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

36. The circuit according to claim 33 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

37. The circuit according to claim 33 wherein said means for photon sensing is manufactured in N-well technology together with some kind of guard ring.

38. The circuit according to claim 33 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

39. A circuit manufactured as an integrated circuit formed on a single chip, capable of detecting and sensing photons and generating an appropriate output signal having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

a photo diode connected to both the gate input of a field effect transistor and to one contact of a switching device;

said switching device also connected to said supply voltage;

said field effect transistor connected with its drain input to said supply voltage and connected with its source input to both a current source and a control circuit;

said current source also connected to ground; and

said control circuit generating said appropriate output signal of the circuit.

40. The circuit according to claim 39 representing an essential part of implementing a mobile phone to computer data link.

41. The circuit according to claim 39 representing an essential part of implementing a computer-to-computer data link.

42. The circuit according to claim 39 representing an essential part of implementing a computer to peripheral data link.

43. The circuit according to claim 39 representing an essential part of implementing a computer to television set data link.

44. The circuit according to claim 39 representing an essential part of implementing a data link with additional power regulation features.

45. The circuit according to claim 39 representing an essential part of implementing a radiation intensity measurement system.

46. The circuit according to claim 39 representing an essential part of implementing a reflection measurement system.

47. The circuit according to claim 39 representing an essential part of implementing a position detection system.

48. The circuit according to claim 39 representing an essential part of implementing a reflection measurement system with visible or invisible light spectra.

49. The circuit according to claim 39 manufactured in monolithic integrated CMOS circuit technology.

50. The circuit according to claim 49 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

51. The circuit according to claim 49 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

52. The circuit according to claim 49 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

53. The circuit according to claim 49 wherein said means for photon sensing is, manufactured in N-well technology together with some kind of guard ring.

54. The circuit according to claim 49 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

55. A circuit, capable of detecting and sensing photons and generating an appropriate output signal having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

a photo diode having an anode terminal connected to ground and a cathode terminal connected to both the gate input of a field effect transistor and to one contact of a single pole switch;

a switching device having said one single pole switch with a single contact on each side wherefrom said one contact is connected to one of said terminals of supply voltages and said contact on the other side of said switch is connected to both said cathode of said photo diode and said gate input of said field effect transistor;

said field effect transistor having said gate input and drain and source connections wherein said drain connection is wired to one of said terminals of supply voltages and said source connection to one terminal of a current source and wherein said gate input is connected to said cathode and switch contact connection point;

said current source having two terminals and driving said field effect transistor wherefrom said one terminal is connected to ground and said other terminal to both said source connection of said field effect transistor and an input terminal of a control circuit thus delivering an intermediate output voltage signal; and

said control circuit in form of a three-pole circuit having said input and an output terminal and a common ground terminal for both said input and output for the processing of said intermediate output voltage signal, delivered from said field effect transistor, thus generating said appropriate output signal of the circuit.

56. The circuit according to claim 55 manufactured in monolithic integrated circuit technology.

57. The circuit according to claim 56 manufactured in monolithic integrated CMOS technology.

58. The circuit according to claim 57 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

59. The circuit according to claim 57 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

60. The circuit according to claim 57 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

61. The circuit according to claim 57 wherein said means for photon sensing is manufactured in N-well technology together with some kind of guard ring.

62. The circuit according to claim 57 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

63. A circuit manufactured as an integrated circuit formed on a single chip, capable of detecting and sensing photons and generating an appropriate output signal having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

a photo diode having an anode terminal connected to ground and a cathode terminal connected to both the gate input of a field effect transistor and to one contact of a single pole switch;

a switching device having said one single pole switch with a single contact on each side wherefrom said one contact is connected to one of said terminals of supply voltages and said contact on the other side of said switch is connected to both said cathode of said photo diode and said gate input of said field effect transistor;

said field effect transistor having said gate input and drain and source connections wherein said drain connection is wired to one of said terminals of supply voltages and said source connection to one terminal of a current source and wherein said gate input is connected to said cathode and switch contact connection point;

said current source having two terminals and driving said field effect transistor wherefrom said one terminal is connected to ground and said other terminal to both said source connection of said field effect transistor and an input terminal of a control circuit thus delivering an intermediate output voltage signal; and

said control circuit in form of a three-pole circuit having said input and an output terminal and a common ground terminal for both said input and output for the processing of said intermediate output voltage signal, delivered from said field effect transistor, thus generating said appropriate output signal of the circuit.

64. The circuit according to claim 63 manufactured in monolithic integrated CMOS technology.

65. The circuit according to claim 64 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

66. The circuit according to claim 64 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

67. The circuit according to claim 64 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

68. The circuit according to claim 64 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

69. A circuit, capable of detecting and sensing photons under consideration of side effects such as temperature changes, drift, aging and ambient light influences thus generating an appropriately corrected output signal of the circuit, and having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

two sets of a basic photo sensitive circuit being operated in parallel to each other, one set in light mode and the other in dark mode;

each set comprising;

a photo;

diode connected to both the gate input of a field effect transistor and to one contact of a switching device;

said switching device also connected to said supply voltage;

said field effect transistor connected with its drain input to said supply voltage and connected with its source input to both a current source and an amplifier input;

said current source also connected to ground; and

a common differential amplifier used commonly for both sets thus having two of said amplifier inputs and outputs;

with

a common control circuit for the processing of the signals delivered from said outputs of said operational amplifier, thus generating said appropriately corrected output signal of the circuit.

70. The circuit according to claim 69 representing an essential part of implementing a mobile phone to computer data link.

71. The circuit according to claim 69 representing an essential part of implementing a computer-to-computer data link.

72. The circuit according to claim 69 representing an essential part of implementing a computer to peripheral data link.

73. The circuit according to claim 69 representing an essential part of implementing a computer to television set data link.

74. The circuit according to claim 69 representing an essential part of implementing a data link with additional power regulation features.

75. The circuit according to claim 69 representing an essential part of implementing a radiation intensity measurement system.

76. The circuit according to claim 69 representing an essential part of implementing a reflection measurement system.

77. The circuit according to claim 69 representing an essential part of implementing a position detection system.

78. The circuit according to claim 69 representing an essential part of implementing a reflection measurement system with visible or invisible light spectra.

79. The circuit according to claim 69 manufactured in monolithic integrated technology.

80. The circuit according to claim 79 manufactured in monolithic integrated CMOS technology.

81. The circuit according to claim 80 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

82. The circuit according to claim 80 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

83. The circuit according to claim 80 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

84. The circuit according to claim 80 wherein said means for photon sensing is manufactured in N-well technology together with some kind of guard ring.

85. The circuit according to claim 80 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.

86. A circuit manufactured as an integrated circuit formed on a single chip, capable of detecting and sensing photons under consideration of side effects such as temperature changes, drift, aging and ambient light influences thus generating an appropriately corrected output signal of the circuit, and having an optical input facility and an output terminal as well as terminals for supply voltages and ground connections, comprising:

two sets of a basic photo sensitive circuit being operated in parallel to each other, one set in light mode and the other in dark mode;

each set comprising;

a photo diode connected to both the gate input of a field effect transistor and to one contact of a switching device;

said switching device also connected to said supply voltage;

said field effect transistor connected with its drain input to said supply voltage and connected with its source input to both a current source and an amplifier input;

said current source also connected to ground; and

a common differential amplifier used commonly for both sets thus having two of said amplifier inputs and outputs;

with

a common control circuit for the processing of the signals delivered from said outputs of said operational amplifier, thus generating said appropriately corrected output signal of the circuit.

87. The circuit according to claim 86 manufactured in monolithic integrated CMOS technology.

88. The circuit according to claim 87 manufactured in monolithic integrated CMOS circuit technology with additional deep N-well technology features.

89. The circuit according to claim 87 manufactured in monolithic integrated CMOS circuit technology with additional deep P-well technology features.

90. The circuit according to claim 87 manufactured in monolithic integrated CMOS technology with additional triple well technology features.

91. The circuit according to claim 87 wherein said means for photon sensing is manufactured in N-well technology together with some kind of guard ring.

92. The circuit according to claim 87 wherein said means for photon sensing is manufactured in P-well technology together with some kind of guard ring.