OPTOELECTRONIC SENSOR DEVICE, DETECTOR AND ELECTRONIC DEVICE, AND METHOD OF OPERATING SUCH A SENSOR DEVICE OR DETECTOR

Abstract

An optoelectronic sensing device may include an optoelectronic detection device configured to detect light and provide an electrical signal as a function of detected light. The device may further include a signal detection device configured to store at least one signal value of the electrical signal in a memory during a time interval of repeating time intervals and to output an indication signal after the time interval has elapsed.

Claims

1. An optoelectronic sensor device comprising: an optoelectronic detection device configured to detect light and configured to provide an electrical signal as a function of detected light based on a detected light intensity; a communication interface; and a signal detection device configured to store at least one signal value of the electrical signal in a memory during a time interval of repetitive time intervals and to output a display signal over the communication interface after the time interval has elapsed.

2. The optoelectronic sensor device according to claim 1, wherein the time interval is adjustable.

3. The optoelectronic sensor device according to claim 1, wherein the display signal corresponds to a first value of a digital signal.

4. The optoelectronic sensor device according to claim 3, wherein the sensor device is configured to output a second value of the digital signal different from the first value, outside a time period during which the display signal corresponding to the first value is output.

5. The optoelectronic sensor device according to claim 3, wherein the sensor device is adapted to change the first value into a second value as soon as at least one byte of the signal value is read out from the memory.

6. (canceled)

7. The optoelectronic sensor device according to claim 1, wherein the signal detection device is configured to store at least one value of the respective current time interval in the memory.

8. The optoelectronic sensor device according to claim 7, wherein the signal detection device is configured to delete or overwrite the at least one value from a preceding time interval from the memory.

9. The optoelectronic sensor device according to claim 1, wherein the display signal corresponds to a first value of a digital signal; and the sensor device is configured to change the first value to a second value as soon as at least one byte of the signal value is read out from the memory.

10. The optoelectronic sensor device according to claim 1, wherein the sensor device is configured to store exactly one signal value per time interval in the memory.

11. The optoelectronic sensor device according to claim 1, wherein the memory is a memory register.

12. A detector comprising: an optoelectronic sensor device according to claim 1; and a control device in communication with the sensor device.

13. The detector according to claim 12, wherein the control device is configured to determine the time interval.

14. The detector according to claim 12, wherein: the control device is configured to detect the display signal between the sensor device and the control device; and in response to the detection of the display signal, the control device is configured to read out the at least one signal value from the memory of the sensor device.

15. The detector according to claim 14, wherein the control device is configured to collect the read-out signal values from several successive time intervals.

16. The detector according to claim 1, wherein the control device is configured to determine a flicker frequency for the detected light as a function of the signal values of a plurality of successive time intervals.

17. An electronic device comprising: an optoelectronic sensor device according to claim 1; a housing; wherein the optoelectronic detection device is arranged in the housing in such a way that light incident from outside is detectable.

18. The electronic device according to claim 17, wherein the electronic device is a cell phone, smartphone, tablet, or camera.

19. A method of operating an optoelectronic sensor device according to claim 1, wherein: an electrical signal is provided during a repetitive time interval, the electrical signal being generated in response to the detected light intensity; during the time interval at least one signal value of the electrical signal is stored in the memory; and the display signal is output over the communication interface after the time interval has elapsed.

20. A method of operating a detector according to claim 12, wherein: the sensor device is configured to output the display signal after the time interval has elapsed, the control device is configured to detect the display signal; and in response to the detection of the display signal, the control device is configured to read out the at least one signal value from the memory of the sensor device; after reading out, the display signal is not displayed until the next time interval has elapsed; and during the next time interval again at least one or exactly one signal value of the electrical signal is stored in the memory.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In the following, embodiments are explained in more detail with reference to the accompanying drawings. They show, schematically in each case,

[0045] FIG. 1 a block diagram of a detector with a sensor device and a control device,

[0046] FIG. 2 block diagram of a detector with a sensor device and a control device, and

[0047] FIG. 3 time lapse diagram of a sensor device.

DETAILED DESCRIPTION

[0048] The detector shown in FIG. 1 comprises an optoelectronic sensor device 11 and a control device 13 which is in communication with the sensor device 11. Both the sensor device 11 and the control device 13 may be implemented in a respective chip.

[0049] The sensor device 11 includes an optoelectronic detection device 15, in this case in the form of a plurality of photodiodes, each having a detector surface for detecting light. Each photodiode 15 can detect light of different wavelengths, for example, by arranging different color filters in front of the detector surfaces of the photodiodes 15. This enables a spectral resolution of the detected light.

[0050] Each photodiode 15 generates an electrical signal in response to the light detected by the photodiode 15, which is provided to a signal conditioning circuit 17 associated with the respective photodiode 15. In a respective signal conditioning circuit 17, the signal provided by the associated photodiode 15 can be manipulated to be suitable for analog-to-digital conversion, for example. In this regard, the signal may be processed, for example, by means of an anti-aliasing filter. Furthermore, the electrical signal can be converted into a digital signal value in the respective signal conditioning circuit 17.

[0051] The sensor device 11 may have a signal detection device 21 comprising at least one data memory 19. A respective digital signal value can be stored in the data memory 19. Signal values from different photodiodes 15 may be stored in different data memories 19, in particular memory registers.

[0052] The signal detection device 21 may include an optional command register 23 in which commands for controlling the signal conditioning circuits 17 may be stored and applied.

[0053] The signal detection device 21 comprises a communication interface 25 by means of which communication with the control device 13 can take place. The communication interface 25 may be an I2C interface that enables communication via clock (SCL) and data (SDA) lines. I2C stands for Inter-Integrated Circuit.

[0054] In addition, the signal detection device 21 includes an interrupt output 27, also called an interrupt pin, through which an interrupt signal INT can be output, which in turn can be detected by the control device 13.

[0055] The detector, shown in a block diagram in FIG. 2, comprises a sensor device 11 and a control device 13, which is in communication with the sensor device 11. Both the sensor device 11 and the control device 13 may be implemented as a chip. For example, the sensor device 11 may be implemented as an integral circuit in a silicon chip.

[0056] The sensor device 11 comprises an optoelectronic detection device 15, for example in the form of one or more photodiodes or in the form of a photodiode array. The detection device 15 is configured to detect light and provides an electrical signal as a function of detected light. For example, a photodiode generates an electrical current as a function of the intensity of light absorbed by the photodiode. Furthermore, the detection device 15 may comprise an analog-to-digital converter so that the electrical signal can be provided in the form of an instantaneous signal value.

[0057] A signal detection device 21 is provided for storing a signal value of the electric signal in a memory 19 during a time interval of repetitive time intervals. For determining a flicker frequency, for example, if several photodiodes are present per time interval, the signal value of that photodiode can be stored which detects light in a wavelength range which is at or at least near the maximum of the spectral brightness sensitivity of the human eye in daylight. Thus, a kind of photopic response can be detected.

[0058] After the time interval has elapsed, the signal detection device 21 outputs an indication signal via an interrupt output 27 which can be received by the control device 13. The indication signal is a first state, such as the low state, of an interrupt signal which is otherwise output in its second state, such as its higher state.

[0059] The control device 13 can communicate with the sensor device 11 via the communication interface 25. In particular, the control device 13 can determine the length of the time interval and read the signal value stored in the memory 19 during a time interval.

[0060] FIG. 3 illustrates the operation of the sensor device 11 in a time lapse diagram over several successive time intervals T. In the bottom line A, the state of the sensor device 11 is indicated. In the middle line I2C, a communication is indicated via the communication interface 25, which is an I2C communication interface. In the top line the signal INT at the interrupt output 27 is displayed.

[0061] During the first time interval T, 301 the control device 13 is in an idle mode, also referred to as standby mode. Communication 303 between the control device 13 and the sensor device 11 starts via the communication interface 25. A normal state 305 of the interrupt signal is indicated at the interrupt output 27 (cf. INT), here in the form of a high signal level.

[0062] During the 2nd time interval T, 307 a measurement takes place (see “Measurement in progress” 309 in the 3rd line of FIG. 3). During this time interval 307, a determined signal value of the electrical signal is stored in the memory 19.

[0063] After the 2nd time interval 307 has elapsed and thus at the beginning of a subsequent 3rd time interval 311, the display signal 313 is output at the interrupt output 27 (INT) by switching the output interrupt signal from the normal state (see INT, 305) to a state with a low signal level. This state 313 remains for a time duration t1. The time duration t1 may correspond to a period of time required to read out from memory a first byte of the signal value determined during the 2nd time interval 307.

[0064] After the time period t1 has elapsed, the state at the interrupt output 27 changes back to the normal state 305. INT thus returns to the normal state 305 with a high signal level. As shown in the 2nd line in FIG. 3, a data transmission 315 between the control device 13 and the sensor device 11 to read out all bytes of the signal value from the previous time interval may extend over a large part of the subsequent time interval. For example, the time period t1 may be approximately half as long as the duration of the data transmission 315.

[0065] The above process is repeated accordingly for the subsequent time windows, for example a fourth and fifth time window 317 and 319. The measurement process ends with a corresponding command from the control device 13 to the sensor device 11 (not shown).

[0066] The control device 13 or a downstream device can collect the signal values measured over several time intervals T and process them further. For example, an FFT method can be used to calculate any flicker frequency of the detected light. The maximum possible flicker frequency that can be determined results from the inverse of twice the time duration (f.sub.max=1/(2*T)).

REFERENCE LIST

[0067] 11 sensor device [0068] 13 control device [0069] 15 detection device, photodiode [0070] 17 signal conditioning circuit [0071] 19 data storage [0072] 21 signal acquisition device [0073] 23 command register [0074] 25 communication interface [0075] 27 interrupt output [0076] 301 first time interval [0077] 303 communication starts [0078] 305 normal state [0079] 307 second time interval [0080] 309 measurement running [0081] 311 time interval [0082] 313 Display signal [0083] 315 Data transmission [0084] 317 fourth duration [0085] 319 fifth period [0086] INT Interrupt signal [0087] SCL clock line [0088] SDA data line [0089] T time interval [0090] t1 Duration [0091] t2 Duration