Infrared lamp driving circuit, eyeball tracking device and electronic equipment

Abstract

The invention discloses an infrared lamp driving circuit, an eyeball tracking device and electronic equipment, and the infrared lamp driving circuit comprises a power management module, a driving module, an infrared lamp array and a protection module. The driving module is electrically connected with the infrared lamp array and is used for driving the infrared lamps; the power management module is electrically connected with the driving module and is used for providing working voltage for the driving module; the protection module is electrically connected with the infrared lamp array and is used for detecting the value of current flowing through the infrared lamp; the protection module is also used for controlling the power management module to reduce the working voltage output to the driving module when the current value exceeds a first set threshold value; and / or the protection module is also used for controlling an enable signal sent to the power management module to be in an invalid level state when the current value exceeds a second set threshold value; therefore, the power management module stops providing the working voltage for the driving module. According to the technical scheme provided by the invention, the power of the infrared lamp can be safely controlled.

Description

Technical Field

[0001] The present invention relates to the field of eye tracking technology, and in particular to an infrared lamp driving circuit, an eye tracking device, and an electronic device. Background Art

[0002] Eye tracking, also known as line of sight tracking, is a technology that estimates the line of sight and / or fixation point of the eyes by measuring eye movement. When a person's eyes look in different directions, there will be subtle changes in the eyes, and these changes will produce extractable features. Computers can extract these features through image capture or scanning, thereby tracking the changes in the eyes in real time, predicting the user's state and needs, and responding to achieve the purpose of controlling the device with the eyes. One of the more common methods of eye tracking currently is to use an infrared light source to illuminate the human eye and use a camera or video camera to record the subject's eye movement, that is, to obtain an eye image reflecting the eye movement, and extract eye features from the obtained eye image to establish a line of sight / fixation point estimation model.

[0003] If the power of the infrared light source is too high, it will cause damage to the human eye. The existing technology does not contain an active current detection solution. Specifically, the abnormal processing is controlled by the lamp driver chip. There is no solution to the failure caused by the lamp driver chip itself, which poses a great safety hazard. Summary of the invention

[0004] The embodiment of the present invention provides an infrared lamp driving circuit, an eye tracking device, and an electronic device to achieve safe control of the power of the infrared lamp.

[0005] In a first aspect, an embodiment of the present invention provides an infrared lamp driving circuit, comprising: a power management module, a driving module, an infrared lamp array and a protection module;

[0006] The driving module is electrically connected to the infrared lamp array and is used to drive the infrared lamps;

[0007] The power management module is electrically connected to the driving module and is used to provide an operating voltage for the driving module;

[0008] The protection module is electrically connected to the infrared lamp array and is used to detect the current value flowing through the infrared lamp; the protection module is also used to control the power management module to reduce the operating voltage output to the driving module through a current control signal when the current value exceeds a first set threshold; and / or,

[0009] The protection module is also used to control the enable signal sent to the power management module to an invalid level state when the current value exceeds a second set threshold value, so that the power management module stops providing the operating voltage to the driving module.

[0010] In a second aspect, an embodiment of the present invention provides an eye tracking device, comprising: an image acquisition device; an infrared light source; and an infrared light driving circuit provided by any embodiment of the present invention.

[0011] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising the eye tracking device provided by any embodiment of the present invention.

[0012] In the present invention, in addition to the power management module, the driving module and the infrared lamp array, the infrared lamp driving circuit is also provided with a protection module. Specifically, the power management module can provide a working voltage for the driving module so that the driving module drives each infrared lamp of the infrared lamp array. The protection module is directly connected to the infrared lamp array, and can detect the current value flowing through the infrared lamp, reduce the working voltage output by the power management module when the current value exceeds the first set threshold, or control the enable signal sent by the protection module to the power management module to an invalid level state when the current value exceeds the second set threshold, so that the power management module stops providing the working voltage for the driving signal. The embodiment of the present invention actively performs safety detection of the current value through the protection module, and can learn about the abnormal current situation in advance and reduce or disconnect the working voltage in time, especially the abnormal current situation caused by the abnormality of the driving module itself. In the prior art, only the driving module detects the abnormal current, which is prone to the situation that there is no timely response plan for the abnormal current value caused by the abnormal driving module. The embodiment of the present invention can effectively improve the safety and reliability of the infrared lamp driving circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of an infrared lamp driving circuit provided by an embodiment of the present invention;

[0014] Figure 2 A schematic diagram of the structure of another infrared lamp driving circuit provided by an embodiment of the present invention;

[0015] Figure 3 A schematic diagram of the structure of a driving module provided by an embodiment of the present invention;

[0016] Figure 4 A schematic diagram of the structure of an infrared lamp array provided by an embodiment of the present invention;

[0017] Figure 5 A schematic diagram of the structure of a power management module provided by an embodiment of the present invention;

[0018] Figure 6 A schematic diagram of the structure of a power management module provided by an embodiment of the present invention;

[0019] Figure 7 A schematic diagram of the structure of an eye tracking device provided by an embodiment of the present invention;

[0020] Figure 8 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0022] One of the more common methods in eye tracking methods is to use an infrared lamp to illuminate the human eye and use a camera or video camera to record the subject's eye movement, that is, to obtain an eye image reflecting the eye movement, and extract eye features from the obtained eye image to establish a line of sight / fixation point estimation model. If the power of the infrared lamp is too large, it will cause damage to the human eye. In the prior art, the infrared lamp is controlled by the infrared lamp driver chip. When the infrared lamp driver chip detects that the current of the infrared lamp is abnormal, the driver chip responds to it, for example, disconnecting the power supply of the infrared lamp, or increasing or decreasing the current flowing through the infrared lamp. However, the inventors found in the process of implementing the present invention that if the driver chip itself is abnormal or fails, the current value of the infrared lamp cannot be controlled, and the power of the infrared lamp cannot be controlled. In response to this situation, the current infrared lamp drive circuit has no response plan, and the safety hazard is relatively large.

[0023] To solve the above problems, an embodiment of the present invention provides an infrared lamp driving circuit, such as Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of an infrared lamp driving circuit provided by an embodiment of the present invention. The infrared lamp driving circuit specifically includes: a power management module 11, a driving module 12, an infrared lamp array 13 and a protection module 14;

[0024] The driving module 12 is electrically connected to the infrared lamp array 13 and is used to drive the infrared lamps;

[0025] The power management module 11 is electrically connected to the driving module 12 and is used to provide a working voltage for the driving module 12;

[0026] The protection module 14 is electrically connected to the infrared lamp array 13, and is used to detect the current value flowing through the infrared lamp; the protection module 14 is also used to control the power management module 11 to reduce the operating voltage output to the driving module 12 through a current control signal when the current value exceeds a first set threshold; and / or, the protection module 14 is also used to control the enable signal sent to the power management module 11 to an invalid level state when the current value exceeds a second set threshold; so that the power management module 11 stops providing the operating voltage to the driving module 12.

[0027] Optionally, the second set threshold value may be greater than the first set threshold value. In this embodiment, when the current value exceeds the first set threshold value, the operating voltage output by the power management module 11 to the driving module 12 can be reduced, and when the current value is greater, that is, exceeds the second set threshold value, the power management module 11 can directly stop providing the operating voltage to the driving module 12, thereby providing a double protection solution for the infrared lamp driving circuit.

[0028] In the embodiment of the present invention, in addition to the power management module, the driving module and the infrared lamp array, the infrared lamp driving circuit is also provided with a protection module. Specifically, the power management module can provide a working voltage for the driving module so that the driving module drives each infrared lamp of the infrared lamp array. The protection module is directly connected to the infrared lamp array, and can detect the current value flowing through the infrared lamp, and reduce the working voltage output by the power management module when the current value exceeds the first set threshold, or control the enable signal sent by the protection module to the power management module to an invalid level state when the current value exceeds the second set threshold, so that the power management module stops providing the working voltage for the driving signal. In the embodiment of the present invention, the protection module actively performs a safety detection of the current value, and the abnormal current situation can be known in advance and the working voltage can be reduced or disconnected in time, especially the abnormal current situation caused by the abnormality of the driving module itself can be known. In the prior art, only the driving module detects the abnormal current, which is prone to the situation that there is no timely response plan for the abnormal current value caused by the abnormal driving module. The embodiment of the present invention can effectively improve the safety and reliability of the infrared lamp driving circuit.

[0029] The above is the core idea of ​​the present invention. The technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In this embodiment, the power management module 11 is used to supply power to the entire infrared lamp driving circuit. The power management module 11 is electrically connected to the driving module 12, and can provide a working voltage to the driving module 12. The driving chip 12 is electrically connected to the infrared lamp array 13, and can further provide a working voltage to the infrared lamp array 13. The infrared lamp array 13 includes a plurality of infrared lamps, and the array formed by the infrared lamps can effectively acquire eye images.

[0031] In this embodiment, the infrared lamp driving circuit also includes: a protection module 14. The protection module 14 can detect the current value flowing through the infrared lamp. The protection module 14 can also be electrically connected to the power management module 11, and is used to send a current control signal to the power management module 11. When it is detected that the current value of the infrared lamp is greater than the first set threshold, the power management module 11 is controlled by the current control signal to reduce the working voltage output to the driving module 12, so that the driving module 12 reduces the current value output to the infrared lamp to avoid the infrared lamp from causing damage to the human eye. Alternatively, optionally, the protection module 14 can also be electrically connected to the power management module 11, and is used to send an enable signal to the power management module 11. The above-mentioned enable signal has two states: a valid level state and an invalid level state. When the enable signal is in a valid level state, the power management module 11 can provide a working voltage to the driving module 12; when the enable signal is in an invalid level state, the power management module 11 stops providing a working voltage to the driving module 12. For example, the enable signal is in a valid level state at a high level, and the enable signal is in an invalid level state at a low level; or, the enable signal is in a valid level state at a low level, and the enable signal is in an invalid level state at a high level. When the current value exceeds the second set threshold, the protection module 14 controls the enable signal sent by the protection module 14 to the power management module 11 to be in an invalid level state, so that the power management module 11 stops providing the working voltage to the driving module 12. Regardless of whether the driving module 12 fails, the protection module 14 can control the current value of the infrared lamp array 13, thereby preventing the infrared lamp from emitting too much power and causing damage to the human eye. It should be noted that the above-mentioned second set threshold can be set according to the human eye's acceptance of infrared light to ensure that the current value is not harmed by infrared light at the second set threshold. In this embodiment, optionally, the second set threshold can be greater than the first set threshold, so that when the current value is large, the current value of the infrared lamp can be reduced. When the current value is too large, the infrared lamp is directly turned off to prevent the situation where the infrared lamp power cannot be guaranteed to be within a safe range even if the current value is reduced.

[0032] Figure 2 The schematic diagram of another infrared lamp driving circuit provided by an embodiment of the present invention is as follows. Optionally, the infrared lamp driving circuit may further include: a control module 15; the control module 15 is electrically connected to the driving module 12, and is used to send a PWM adjustment signal to the driving module 12; the driving module 12 adjusts the working voltage output to the infrared lamp according to the PWM adjustment signal. The control module 15 can output a PWM adjustment signal to the driving module 12, for example, Figure 3 As shown, Figure 3A schematic diagram of the structure of a driving module provided by an embodiment of the present invention. The driving module may include a logic gate chip U1 and a boost driving chip U2. The logic gate chip U1 obtains the above-mentioned PWM adjustment signal through the terminal EN / PWM and sends it to the terminal CTRL of the boost driving chip U2. Then, the boost driving chip U2 adjusts the size of the final output current according to the PWM adjustment signal. The boost driving chip U2 outputs the current value through the terminal SW, which is then filtered by the diode D1 and the capacitor C1, and then transmitted to the infrared lamp array through the terminal LEDA+.

[0033] Figure 4 A schematic diagram of the structure of an infrared lamp array provided by an embodiment of the present invention. Optionally, the infrared lamp array may include multiple infrared lamps, for example, LED1 to LED (2n) with a total of 2n infrared lamps, where n is an integer greater than or equal to 1; multiple infrared lamps are connected in series or in parallel. Figure 4 In the figure, infrared lamps are connected in series for illustration. The specific connection method of the infrared lamps is not limited in this embodiment. Optionally, the infrared lamps can be formed into a matrix, a circle, an ellipse, etc., so as to form a light spot on the eye and illuminate the eye.

[0034] Figure 5 A schematic diagram of the structure of a power management module provided by an embodiment of the present invention. Figures 3 to 5 , the protection module 14 may include a monitoring chip U3. Specifically, the output terminal VOUT of the power management module 11 is connected to the terminal VIN of the driving module 12 to provide an operating voltage for the driving module 12. The driving module 12 is connected to the infrared lamp array 13 through the terminal LEDA+, and the output terminal LEDC+ of the infrared lamp array 13 is connected to the input terminal IN+ of the protection module 14. The protection module 14 sends the enable signal LED_PWR_ERR_N to the power management module 11 through the output terminal ALERT#. When the enable signal LED_PWR_ERR_N is in a valid level state, the power management module 11 supplies power to the driving module 12.

[0035] In addition, if Figure 2 and Figure 5 As shown, the protection module 14 is connected to the current feedback pin IR_FB of the driving module 12, and the protection module 14 feeds back the current value of the infrared lamp array 13 to the driving module 12, and the driving module 12 can also control the current value. That is, in this embodiment, the driving module 12 and the protection module 14 monitor and control the current value at the same time, further increasing the reliability of the entire infrared lamp driving circuit, effectively avoiding the problem of excessive power of the infrared lamp, and protecting the eyes.

[0036] Figure 6 A schematic diagram of the structure of a power management module provided by an embodiment of the present invention. Figure 2 and Figure 6 As shown, the control module 15 is connected to the terminal LED_OCP of the power management module 11, and can be used to obtain the enable signal LED_PWR_ERR_N; the control module 15 can also be used to reduce the duty cycle of the PWM adjustment signal when it is detected that the enable signal LED_PWR_ERR_N is in an invalid level state, until the enable signal LED_PWR_ERR_N is in a valid level state; the power management module 11 is used to provide an operating voltage to the driving module 12 when the enable signal LED_PWR_ERR_N is in a valid level state.

[0037] This embodiment ensures that after the current value of the infrared lamp array exceeds the second set threshold, the protection module 14 controls the power management module 11 to stop supplying power to the driver module 12, so as to prevent the excessive power of the infrared lamp from causing damage to the eyes. In addition, in this embodiment, the control module 15 is connected to the power management module 11, and can restore the current to a reasonable range, that is, when the control module 15 detects that the enable signal of the power management module 11 is in a valid level state, it continues to control the power management module 11 to supply power to the driver module 12. This embodiment makes the control module more intelligent. Specifically, when the current value of the infrared lamp array fluctuates less, that is, when the overcurrent phenomenon can be eliminated quickly, the control module 15 can quickly restore the current value to a reasonable range by reducing the duty cycle of the PWM adjustment signal until the enable signal LED_PWR_ERR_N is in a valid level state, the power management module 11 continues to supply power to the driver module 12, and the infrared lamp array can also quickly resume work, thereby improving the efficiency of eye tracking.

[0038] Continue to refer Figure 2 and Figure 6 Optionally, the control module 15 can also be used to control the enable signal LED_PWR_ERR_N issued by the protection module 14 to remain in an invalid level state if the enable signal LED_PWR_ERR_N continues to be in an invalid level state after reducing the duty cycle of the PWM adjustment signal. Of course, when the current value of the infrared lamp array fluctuates greatly, and the current value cannot be restored to a reasonable range by reducing the duty cycle of the small PWM adjustment signal, the control module 15 directly controls the enable signal LED_PWR_ERR_N issued by the protection module 14 to remain in an invalid level state, quickly stop the infrared lamp array from working, and protect the eyes.

[0039] In a specific example, the low level of the enable signal LED_PWR_ERR_N is set to an invalid level state, and the high level of the enable signal LED_PWR_ERR_N is set to a valid level state. If the control module 15 obtains the enable signal LED_PWR_ERR_N as a low level through the terminal LED_OCP, the duty cycle of the PWM adjustment signal is reduced, and it is detected whether the enable signal LED_PWR_ERR_N is a high level. If not, the duty cycle of the PWM adjustment signal continues to be reduced until the enable signal LED_PWR_ERR_N is a high level. Then the duty cycle of the PWM adjustment signal is increased to restore to a normal working state, and the enable signal LED_PWR_ERR_N is detected to be a high level. If the enable signal LED_PWR_ERR_N is a high level, it means that the fluctuation of the current value of the infrared lamp array is eliminated and the normal working state has been restored. However, if after increasing the duty cycle of the PWM regulation signal to restore to a normal working state, the enable signal LED_PWR_ERR_N is monitored to be at a low level, the process of "decreasing the duty cycle of the PWM regulation signal until the enable signal LED_PWR_ERR_N is at a high level, and then increasing the duty cycle of the PWM regulation signal to restore to a normal working state" can be repeated n times. If the enable signal LED_PWR_ERR_N remains at an invalid level, the power management module 11 is directly shut down through the protection module 14.

[0040] The above example is the automatic adjustment process of the infrared lamp driving circuit after the current value exceeds the second set threshold value. It does not require manual operation. It can automatically adjust the current value when there is a small fluctuation in the current value to prevent the infrared lamp power from being too high. It can also turn off the power management module when the current value changes too much to control the entire infrared lamp driving circuit to stop working. The reliability and safety of the infrared lamp driving circuit in this embodiment are much higher than the solution of controlling the current value only by the driver chip.

[0041] Continue to refer Figure 2 and Figure 6 Optionally, the control module 15 is connected to the protection module 14, and is used to send a reset signal RESET to the protection module 14; the control module 15 is also used to control the reset signal RESET to a valid level state when the enable signal LED_PWR_ERR_N is detected to be in an invalid level state, so that the protection module 14 continues to detect the current value of the infrared lamp. The control module 15 controls the protection module 14 to work through the reset signal RESET. Specifically, when the reset signal RESET is at a valid level, the protection module 14 can restart, so that the protection module 14 continues to detect the current value, thereby outputting the enable signal LED_PWR_ERR_N to the power management module 11.

[0042] After the protection module 14 outputs the enable signal LED_PWR_ERR_N as an invalid level state, the protection module 14 stops detecting the current value. The control module 15 can also send a reset signal RESET to the protection module 14 to restart the protection module 14 so that the protection module 14 detects the current value again. Specifically, when the control module 15 detects that the enable signal LED_PWR_ERR_N is in an invalid level state, the reset signal RESET is controlled to be in a valid level state, and the protection module 14 re-detects the current value. This embodiment further enhances the automation process of the infrared lamp drive circuit, so that processes such as current value detection, current value regulation, and infrared lamp shutdown are automatically executed, thereby improving work efficiency and improving the safety of the infrared lamp drive circuit.

[0043] Continue to refer Figure 2 Optionally, the infrared lamp driving circuit may further include: a control module 15; the control module 15 is connected to the camera 16 and is used to obtain the exposure time; the control module 15 is also used to send a strobe control signal STROBE to the driving module 12 according to the exposure time; the driving module 12 controls the lighting time of the infrared lamp according to the strobe control signal STROBE. In this embodiment, the control module 15 can control the lighting time of the infrared lamp according to the exposure time of the camera, so as to light up the infrared lamp during the exposure time, improve the utilization rate of the infrared lamp, and can turn off the infrared lamp during the non-exposure time to achieve the purpose of saving energy.

[0044] Continue to refer Figure 2 Optionally, the infrared lamp driving circuit may further include: a control module 15; the protection module 14 is also used to detect the current value of the infrared lamp and send the current value to the control module 15; the control module 15 stores the current value. The control module 15 can store the current value of the infrared lamp to facilitate subsequent detection and tracing of the working status of the infrared lamp.

[0045] The embodiment of the present invention also provides an eye tracking device. Figure 7 A schematic diagram of the structure of an eye tracking device provided by an embodiment of the present invention is shown in FIG. Figure 7 As shown, the eye tracking device provided by the embodiment of the present invention includes: an image acquisition device 1; an infrared light source 3; and the infrared light driving circuit 2 described in any embodiment of the present invention.

[0046] The image acquisition device 1 may be a traditional image sensor or an optical sensor based on MEMS (Microelectro Mechanical Systems).

[0047] It should be noted that the eye tracking device in this embodiment includes the technical features of the infrared light driving circuit provided in any embodiment of the present invention, and has the beneficial effects of the corresponding features, which will not be repeated here.

[0048] An embodiment of the present invention further provides an electronic device. Figure 8 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention is shown in FIG. Figure 8 As shown, the electronic device provided by the embodiment of the present invention includes the eye tracking device 4 described in any embodiment of the present invention. The electronic device can be as follows Figure 8 The mobile phone shown in the figure may also be an infrared device such as a computer, a television, a monitoring device, a smart wearable device, etc., and this embodiment does not specifically limit this.

[0049] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An infrared lamp driving circuit, characterized in that: include: Power management module, driver module, infrared light array and protection module; The driving module is electrically connected to the infrared lamp array and is used to drive the infrared lamps; The power management module is electrically connected to the driving module and is used to provide a working voltage for the driving module; the protection module is electrically connected to the infrared lamp array and is used to detect the current value flowing through the infrared lamp; The protection module is further configured to control the power management module to reduce the operating voltage output to the driving module through a current control signal when the current value exceeds a first set threshold; and / or, The protection module is also used to control the enable signal sent to the power management module to an invalid level state when the current value exceeds a second set threshold value, so that the power management module stops providing the operating voltage to the driving module.

2. The infrared lamp driving circuit according to claim 1, characterized in that: Also includes: Control module; The control module is electrically connected to the driving module and is used to send a PWM adjustment signal to the driving module; The driving module adjusts the operating voltage output to the infrared lamp according to the PWM adjustment signal.

3. The infrared lamp driving circuit according to claim 2, characterized in that: The control module is connected to the power management module and is used to obtain the enable signal; the control module is also used to reduce the duty cycle of the PWM regulation signal when detecting that the enable signal is in an invalid level state until the enable signal is in a valid level state; The power management module is used to provide an operating voltage to the driving module when the enable signal is in a valid level state.

4. The infrared lamp driving circuit according to claim 3, characterized in that: The control module is further configured to control the enable signal sent by the protection module to remain in an invalid level state if the enable signal continues to be in an invalid level state after the duty cycle of the PWM regulation signal is reduced.

5. The infrared lamp driving circuit according to claim 3, characterized in that: The control module is connected to the protection module and is used to send a reset signal to the protection module; The control module is also used to control the reset signal to be in a valid level state when it is detected that the enable signal is in an invalid level state, so that the protection module continues to detect the current value of the infrared lamp.

6. The infrared lamp driving circuit according to claim 1, characterized in that: Also includes: Control module; The control module is connected to the camera and is used to obtain the exposure time; The control module is also used to send a gating control signal to the driving module according to the exposure time; The driving module controls the lighting time of the infrared lamp according to the strobe control signal.

7. The infrared lamp driving circuit according to claim 1, characterized in that: The infrared lamp array includes a plurality of infrared lamps; the plurality of infrared lamps are connected in series or in parallel.

8. The infrared lamp driving circuit according to claim 1, characterized in that: Also includes: Control module; The protection module is also used to detect the current value of the infrared lamp and send the current value to the control module; The control module stores the current value.

9. An eye tracking device, characterized in that: include: Image acquisition device; Infrared light source; and the infrared lamp driving circuit as described in any one of claims 1 to 8 above.

10. An electronic device, characterized in that: Including the eye tracking device as claimed in claim 9.

Images