Camera system

Abstract

Title: Camera System The invention relates to a camera system (1) comprising: a camera (2) including an optical sensor (3) and an illuminator (4) configured to illuminate, particularly in the infrared, a target seen by the optical sensor (3); the camera (2) further comprising a power management integrated circuit (5) connected to the optical sensor (3) and optionally to a serializer; a power supply regulator (10) configured to: in an illuminator-off mode (M0), deliver a constant output voltage (Vout) to the power management integrated circuit (5) and zero current to the illuminator (4); in an illuminator-on mode (M1), deliver a predetermined current to the illuminator (4), while simultaneously delivering a voltage to the power management integrated circuit (5). Figure for the abstract: Fig. 1

Description

Title of the invention: Camera system

[0001] The present invention relates to a camera system, in particular configured to be mounted on board a vehicle, in particular an automobile.

[0002] Typically, a camera's power supply uses a voltage regulator for the camera's digital components (optical sensor, serializer, etc.) and a current regulator to supply a specific current to an illuminator when the optical sensor is operating to capture images, in order to control the emitted light output. This therefore requires two regulators, which can be bulky and expensive.

[0003] The present invention aims in particular to remedy the above-mentioned drawbacks.

[0004] The invention thus relates to a camera system comprising: - a camera comprising an optical sensor and an illuminator configured to illuminate, particularly in the infrared, a target seen by the optical sensor, the camera further comprising a power management integrated circuit (designated in English as "PMIC") connected to the optical sensor and possibly to a serializer; - a power regulator configured for: • in an illuminator off mode, deliver at the output, a constant voltage to the power management integrated circuit and zero current to the illuminator; • in an illuminater on mode, deliver a predetermined current to the illuminator, while simultaneously delivering a voltage to the power management integrated circuit.

[0005] Thanks to the invention, the regulator is configured to perform current and voltage regulation depending on the selected mode (illuminator off or on). The invention proposes combining these two voltage and current regulation functions in a single regulator. This makes it possible to reduce the system size because, with only one regulator instead of two, the invention occupies less space. Furthermore, the invention reduces the cost because a single power regulator is used to manage both the digital part of the camera and the illuminator.

[0006] According to one aspect of the invention, the illuminator comprises one or more infrared emitting LEDs, in particular of the laser type.

[0007] According to one aspect of the invention, the camera comprises an optical sensor for capturing video images in the infrared, and a serializer connected to the optical sensor for converting parallel video data into serial data for transmission, in particular by a wired connection, in particular by a coaxial cable, and an electronic control module includes a deserializer configured to receive the data and deserialize this data.

[0008] According to one aspect of the invention, the power regulator includes, in particular, a DC-DC converter. Current regulation can be achieved, in a way, as a reflection of voltage regulation.

[0009] According to one aspect of the invention, the regulator is configured to accept a current that passes through the illuminator.

[0010] According to one aspect of the invention, the regulator is configured to allow regulation (in voltage or current) based on feedback.

[0011] According to one aspect of the invention, the regulator includes for this purpose a return line (or retraction line).

[0012] According to one aspect of the invention, the camera system includes a voltage divider bridge between a regulator output line and a return line (or retraction line).

[0013] According to one aspect of the invention, the divider bridge comprises an electrical resistance Ra and an electrical resistance Rb.

[0014] According to one aspect of the invention, the camera system includes an additional line on which the illuminator and an electrical resistance Rc are arranged in series, and this additional line is connected to the output line of the regulator.

[0015] According to one aspect of the invention, the resistance Rc is lower than the resistance Ra.

[0016] According to one aspect of the invention, the additional line on which the illuminator is located is in parallel (in the electrical sense) with the dividing point.

[0017] According to one aspect of the invention, the voltage divider bridge and the additional line on which the illuminator is located are thus electrically placed between the output line of the regulator and a ground.

[0018] According to one aspect of the invention, the output line of the regulator is connected at the end to the power management integrated circuit (“PMIC”).

[0019] According to one aspect of the invention, the power management integrated circuit (“PMIC”) thus sees the voltage at the output of the regulator.

[0020] According to one aspect of the invention, a feedback link is configured to send a voltage return on the additional line on which the illuminator is located, voltage taken between the illuminator and the resistor, to the regulator.

[0021] Thanks to the voltage divider bridge, it is possible to regulate the voltage (Vout) at the output of the regulator.

[0022] According to one aspect of the invention, the additional line on which the illuminator is located includes a switch configured to be open in illuminator off mode, and to be closed in illuminator on mode.

[0023] According to one aspect of the invention, the switch can be controlled, for example, by an electronic control module to activate or deactivate the illuminator as needed.

[0024] According to one aspect of the invention, when the switch is open (illuminator mode off), the regulator is configured to perform voltage regulation.

[0025] According to one aspect of the invention, when the switch is closed (illuminator mode on), the regulator is configured to perform current regulation.

[0026] The resistance Rc is chosen to be very low compared to the resistance Ra of the divider bridge so that, in illuminater on mode (current regulation), the additional line on which the illuminater is located is predominant compared to the divider bridge.

[0027] Since the resistance Rc is much lower than the resistance Ra, it is the additional line on which the illuminator is located that is seen by the regulator (in illuminator-on mode). The regulator can then be used to regulate the current flowing through the illuminator.

[0028] In illuminator mode, a fixed current passes through the additional line on which the illuminator is located.

[0029] It is possible to consider that this current is variable by using a series resistance which is itself variable.

[0030] In illuminator off mode (zero current through the illuminator), the divider bridge allows voltage regulation.

[0031] According to one aspect of the invention, the power management integrated circuit (“PMIC”) has an operating value range, for example, of 3 and 16 volts.

[0032] According to one aspect of the invention, the system is configured so that the output voltage of the regulator remains within this range.

[0033] The invention further relates to a method for controlling a camera system comprising a camera including an optical sensor and an illuminator configured to illuminate, particularly in the infrared, a target seen by the optical sensor, the camera further comprising a power management integrated circuit (referred to in English as "PMIC") connected to the optical sensor and optionally to a serializer, the method comprising the following steps: - in an illuminator off mode, deliver, using a power regulator, a constant voltage to the power management integrated circuit ("PMIC") and zero current to the illuminator; - in an illuminater on mode, deliver, using the power regulator, a predetermined current to the illuminator, while delivering a voltage to the power management integrated circuit (“PMIC”).

[0034] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and an example of an embodiment given by way of illustration and not limitation with reference to the accompanying schematic drawings on the other hand, in which:

[0035] [Fig-1] Fig. 1 is a schematic representation of the camera system according to a example of implementation of the invention.

[0036] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0037] Figure 1 shows a camera system 1 comprising: - a camera 2 comprising an optical sensor 3 and an illuminator 4 configured to illuminate, in the infrared, a target seen by the optical sensor 3, the camera 2 further comprising a power management integrated circuit 5 (designated in English as "PMIC") connected to the optical sensor 3 and to a serializer 6; - a 10-volt power regulator configured for: • in an illuminator off mode (MO mode), deliver at the output, a constant voltage to the power management integrated circuit 5 and zero current to the illuminator 4; • in an illuminater on mode (Mode Ml), deliver a predetermined current to the illuminator 4, while delivering a voltage to the power management integrated circuit 5.

[0038] The optical sensor 3 is configured to capture video images in the infrared, and the serializer 6 connected to the optical sensor 3 is provided to convert the parallel video data into serial data for transmission to an electronic control module 8 (or ECU).

[0039] The electronic control module 8 includes a deserializer configured to receive data from the serializer 6, and deserialize this data.

[0040] The regulator 10 is configured to perform current and voltage regulation depending on the selected mode (illuminator off or on). The invention proposes combining these two voltage and current regulation functions in the use of a single regulator 10. This makes it possible to reduce the size of the system because, with only one regulator 10 instead of two, the invention allows for a smaller footprint. Furthermore, the invention reduces the cost because a single power supply regulator 10 is used to manage both the digital part of the camera 2 and the illuminator 4.

[0041] The illuminator 4 comprises one or more infrared emitting LEDs, in particular of the laser type.

[0042] The power supply regulator 10 includes, for example, a DC-DC converter. Current regulation can be achieved, in a way, as a representation of voltage regulation.

[0043] The regulator 10 is configured to accept (within the meaning of the regulator 10's own technical specifications) a current which passes through the illuminator 4.

[0044] The regulator 10 is configured to allow regulation (in voltage or current) based on a return or feedback (or “feedback” in English).

[0045] The regulator 10 includes for this purpose a return line 11 (or retraction line).

[0046] The camera system 1 includes a voltage divider bridge 12 between a regulator output line 14 (at voltage Vout) and the return line 11 (or retraction line).

[0047] The divider bridge 12 includes an electrical resistance Ra and an electrical resistance Rb.

[0048] The camera system 1 includes an additional line 16 on which are arranged, in series, the illuminator 4 and an electrical resistance Rc, and this additional line 16 is connected to the output line of the regulator 10.

[0049] The resistance Rc is much lower than the resistance Ra.

[0050] The additional line 16 on which the illuminator 4 is located is in parallel (in the electrical sense) with the dividing point 12.

[0051] The voltage divider bridge 12 and the additional line 16 on which the illuminator 4 is located are thus electrically placed between the output line 14 of the regulator 10 and a ground.

[0052] The output line 14 of the regulator 10 is connected at the end to the power management integrated circuit 5.

[0053] The power management integrated circuit 5 thus sees the output voltage of the regulator 10.

[0054] A feedback link 17 (or "feedback" link) is configured to send to the regulator 10, a voltage return on the additional line 16 on which the illuminator 4 is located, voltage taken between the illuminator 4 and the resistor.

[0055] Thanks to the voltage divider bridge 12, it is possible to regulate the voltage Vout at the output of the regulator 10.

[0056] In the invention, the regulator 10 expects a certain voltage on the feedback line 11. If the measured voltage sent back ("feedback") is greater than a predetermined voltage, the output voltage (Vout) of the regulator 10 is too high, and the regulator 10 reduces the output voltage (Vout). If the output voltage (Vout) of the regulator 10 is too low (i.e., less than a predetermined voltage), the regulator 10 increases the output voltage.

[0057] The additional line 16 on which the illuminator 4 is located includes a switch 19 configured to be open in illuminator off mode (MO), and to be closed in illuminator on mode (Ml).

[0058] The switch 19 can be controlled for example by the electronic control module 8 (via for example a microprocessor) to activate or deactivate the illuminator 4 as required.

[0059] When switch 19 is open (illuminator MO mode off), regulator 10 is configured to perform voltage regulation.

[0060] When the switch is closed (illuminator Ml mode on), the regulator 10 is configured to perform current regulation.

[0061] The resistance Rc is chosen to be very low compared to the resistance Ra of the divider bridge so that, in illuminater on mode (current regulation), the additional line 16 on which the illuminator 4 is located is predominant compared to the divider bridge.

[0062] Since the resistance Rc is much lower (for example, by a factor of at least 10, 20, 50, or 100) than the resistance Ra, it is the additional line 16 on which the illuminator 4 is located that is seen by the regulator 10 (in illuminater-on mode Ml). The regulator 10 can then be used to regulate the current flowing through the illuminator 4.

[0063] In illuminator mode, a fixed current flows in the additional line 16 on which the illuminator 4 is located. In this case: V0=Rc*I(illum) and Vout=V0+U(illum)

[0064] It is specified that I(illum) is the current through the illuminator 4, U(illum) is the voltage across the terminals of the illuminator 4. V0 corresponds to the internal reference voltage of the feedback loop of the regulator 10.

[0065] It is possible to consider that this current is variable by using a series resistance Rc which is itself variable.

[0066] When, for example, the illuminator 4 has a need for 4 amps, the resistance Rc is chosen to allow, in illuminator on mode, a current of 4 amps to pass through the illuminator 4.

[0067] In illuminator off mode (zero current through illuminator 4), the voltage divider allows for voltage regulation. In this case: Vout=V0*Ra / (Ra+Rb)

[0068] The power management integrated circuit 5 has an operating value range, for example, of 3 and 16 volts. The system is configured so that the output voltage (Vout) remains within this range.

[0069] The camera system 1 is configured to be installed on a motor vehicle.

Claims

Demands

1. Camera system (1) comprising: - a camera (2) including an optical sensor (3) and an illuminator (4) configured to illuminate, in particular in the infrared, a target seen by the optical sensor (3), the camera (2) further comprising a power management integrated circuit (5) connected to the optical sensor (3) and optionally to a serializer; - a power regulator (10) configured to: • in an illuminator off mode (MO), deliver a constant output voltage (Vout) to the power management integrated circuit (5) and zero current to the illuminator (4); • in an illuminator on mode (Ml), deliver a predetermined current to the illuminator (4), while delivering a voltage to the power management integrated circuit (5).

2. System according to the preceding claim, wherein the illuminator (4) comprises one or more infrared emitting LEDs, in particular of the laser type.

3. A system according to any one of the preceding claims, wherein the camera (2) includes an optical sensor (3) for capturing video images in the infrared, and a serializer connected to the optical sensor (3) for converting parallel video data into serial data for transmission, in particular by a wired link, in particular by a coaxial cable, and an electronic control module includes a deserializer configured to receive the data and deserialize this data.

4. System according to any one of the preceding claims, wherein the regulator (10) is configured to allow regulation, in voltage or current, as a function of feedback.

5. System according to any one of the preceding claims, wherein the camera system (1) comprises a voltage divider bridge between a regulator output line (10) and a return line (11), and the divider bridge comprises an electrical resistance (Ra) and an electrical resistance (Rb).

6. System according to the preceding claim, wherein the camera system (1) includes an additional line (16) on which are arranged, in series, the illuminator (4) and an electrical resistance (Rc), and this additional line (16) is connected to the output line of the regulator (10), and the resistance (Rc) is lower than the resistance (Ra).

7. System according to the preceding claim, wherein a return link (17) is configured to send a voltage return on the additional line (16) on which the illuminator (4) is located, voltage taken between the illuminator (4) and the resistor, to the regulator (10).

8. System according to claim 6 or 7, wherein the additional line (16) on which the illuminator (4) is located comprises a switch configured to be open in illuminator off mode, and to be closed in illuminator on mode, and the switch is controllable, for example, by an electronic control module to activate or deactivate the illuminator (4) as required.

9. System according to any one of the preceding claims, wherein the power management integrated circuit (5) has an operating value range, for example, of 3 and 16 volts.

10. A method for controlling a camera system (1) comprising a camera (2) including an optical sensor (3) and an illuminator (4) configured to illuminate, particularly in the infrared, a target seen by the optical sensor (3), the camera (2) further comprising a power management integrated circuit (5) connected to the optical sensor (3) and optionally to a serializer, the method comprising the following steps: - in an illuminator off mode, delivering, using a power regulator (10), a constant voltage to the power management integrated circuit (5) and zero current to the illuminator (4); - in an illuminator on mode, delivering, using the power regulator (10), a predetermined current to the illuminator (4), while delivering a voltage to the power management integrated circuit (5).

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