Optical navigation device and optical navigation method of optical navigation device
By introducing detection circuits and control circuits into the optical navigation device, the detection of low characteristic conditions and switching modes are realized, which solves the problem of traditional optical navigation devices producing erroneous displacement data under low characteristic conditions, and improves data accuracy.
Patent Information
- Application Number
- CN202411056461.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-12-08
- Filing Date
- 2024-08-02
- Publication Date
- 2025-06-10
AI Technical Summary
In low characteristic conditions, traditional optical navigation devices may generate erroneous displacement data due to low signal-to-noise ratio, resulting in unnecessary motion data calculations.
An optical navigation device is designed, including an optical sensor, a detection circuit and a control circuit. The detection circuit is used for low feature detection. When a low feature condition is detected, the control circuit will control the optical sensor to switch from operating mode to rest mode to avoid displacement calculations.
By switching modes, erroneous displacement data is avoided under low characteristic conditions, data accuracy is improved, and unnecessary motion data calculation is reduced.
Smart Images
Figure CN120120965A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an optical navigation mechanism, and in particular to an optical navigation device and a corresponding method. Background Art
[0002] Generally speaking, a conventional optical navigation device needs to calculate displacement data or detect motion data in an operating mode. When the number of detected feature points is lower than a minimum feature threshold, the conventional optical navigation device will not calculate displacement data. However, if the number of detected feature points is higher than the minimum feature threshold but the conventional optical navigation device operates in a low feature condition, erroneous displacement data may be generated due to the low signal-to-noise ratio of the low feature condition, thereby calculating and generating unnecessary motion data. Summary of the invention
[0003] Therefore, one of the purposes of the present invention is to disclose a novel optical navigation device and a corresponding method to solve the above problems.
[0004] According to an embodiment, an optical navigation device is disclosed. The optical navigation device includes an optical sensor, a detection circuit, and a control circuit. The optical sensor is used to operate in an operation mode to sense a plurality of pixel images for displacement calculation. The detection circuit is coupled to the optical sensor and is used to perform low feature detection on the sensed plurality of pixel images. The control circuit is coupled to the detection circuit and is used to control the optical sensor to switch from the operation mode to a rest mode when the low feature detection indicates a low feature condition result, wherein the optical sensor does not perform the displacement calculation in the rest mode.
[0005] According to an embodiment, an optical navigation method of an optical navigation device is disclosed. The method includes: providing an optical sensor to operate in an operating mode to sense a plurality of pixel images for displacement calculation; performing low feature detection on the sensed plurality of pixel images; and controlling the optical sensor to switch from the operating mode to a rest mode when the low feature detection indicates a low feature condition result, wherein the optical sensor does not perform the displacement calculation in the rest mode. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 FIG. 4 is a block diagram of an optical navigation device according to an embodiment of the present invention.
[0007] Figure 2 is an operation flow chart of the optical navigation device according to an embodiment of the present invention.
[0008] Figure 3 is a flow chart of the operation of a detection circuit for performing low signature detection according to an embodiment of the present invention.
[0009] Figure 4 is a flow chart of the operation of a detection circuit for performing low signature detection according to various embodiments of the present invention.
[0010] Figure 5 is a flow chart of an operation of a detection circuit for performing low signature detection according to another embodiment of the present invention.
[0011] The reference numerals are described as follows:
[0012] 100 Optical navigation device
[0013] 103 Light-emitting circuit
[0014] 105 Optical Sensor
[0015] 110 Detection circuit
[0016] 115 Control Circuit DETAILED DESCRIPTION
[0017] The object of the present invention is to disclose a technical solution of an optical navigation device and a corresponding method, which is capable of performing a low feature detection on multiple pixel images (or values) of multiple sensed or monitored frames to more accurately detect displacement data, thereby avoiding erroneous or misleading reports of displacement data.
[0018] Please see Figure 1 and Figure 2 . Figure 1 is a block diagram of an optical navigation device 100 according to an embodiment of the present invention. Figure 2 FIG. 1 is an operation flow chart of the optical navigation device 100 according to an embodiment of the present invention. Figure 1 In the embodiment, the optical navigation device 100 is, for example (but not limited to), an optical mouse device, which may include a light emitting circuit 103 (such as a light emitting diode), an optical sensor 105, a detection circuit 110, and a control circuit 115. In other embodiments, the optical navigation device 100 may also be an optical tracking device for different applications, such as a printer device or other different electronic devices.
[0019] The optical navigation device 100 includes a run mode and a rest mode. For example (but not limited to), initially under a preset setting, when it is detected that the user is operating the optical navigation device 100 normally or the optical navigation device 100 is enabled, the optical navigation device 100 can enter the run mode (step S200). In the run mode (step S205), the light emitting diode 103 is configured to emit light to a work surface on which the optical navigation device 100 is placed, and the optical sensor 105 is used to operate in the run mode to receive reflected light to generate and sense multiple pixel images to perform a displacement calculation. Alternatively, in other different applications, the optical navigation device 100 may not include the light emitting diode 103. In this case, the optical sensor 105 can receive reflected light from ambient light to generate and sense multiple pixel images to perform the displacement calculation. In the run mode, the optical sensor 105 can report the displacement data of the performed displacement calculation to a computer device ( Figure 1 ), wherein the displacement data may be a difference value of a position tracking or an absolute value of the position tracking. In addition, in the operation mode, the optical sensor 105 may be used to output and transmit a plurality of pixel images of one or more frames currently sensed to the detection circuit 110.
[0020] The detection circuit 110 is coupled to the optical sensor 105 and is used to perform a low feature detection on the sensed multiple pixel images output by the optical sensor 105. In step S210, the detection circuit 110 is used to determine whether the sensed multiple pixel images are associated with a low feature condition by performing the low feature detection. If the sensed multiple pixel images are not associated with a low feature surface, the detection circuit 110 will output a non-low feature condition result to the control circuit 115, and then in step S220, the control circuit 115 will be used to maintain or keep the optical sensor 105 in the operating mode (i.e., will not switch to the rest mode). Alternatively, if the sensed multiple pixel images are associated with a low feature surface, the detection circuit 110 will output a low feature condition result to the control circuit 115, and then in step S215, the control circuit 115 will be used to control the optical sensor 105 to switch from the operating mode to the rest mode. It should be noted that when the optical sensor 105 switches to the rest mode, the optical sensor 105 will not perform the displacement calculation, that is, no displacement data will be output to the computer device.
[0021] Figure 3is an operation flow chart of the detection circuit 115 for performing the low feature detection according to an embodiment of the present invention. In step S300, when the detection circuit 115 receives the sensed plurality of pixel images from the optical sensor 105, the detection circuit 115 starts to perform the low feature detection on the sensed plurality of pixel images. In this embodiment, in practice, the detection circuit 115 executes a feature extraction engine to extract a plurality of texture features from the sensed plurality of pixel images, and counts the number of total texture features to generate or calculate a surface feature count, i.e., a feature count of the sensed plurality of pixel images. Then, the detection circuit 115 may compare the surface feature count with a specific threshold TH1 (i.e., a low feature count threshold), and compare the surface feature count with a minimum feature count threshold, as shown in step S305. If the surface feature count is less than the specific threshold TH1 and greater than the minimum feature count threshold (i.e., the surface feature count is between the threshold TH1 and the minimum feature count threshold), the detection circuit 115 determines that the surface feature count corresponds to a low feature condition (or may be referred to as a low surface feature condition) and generates a low feature condition result and outputs it to the control circuit 115 (step S310). If the surface feature count is not less than the specific threshold TH1 and greater than the minimum feature count threshold, the detection circuit 115 determines that the surface feature count corresponds to a non-low feature condition (or may be referred to as a non-low surface feature condition) and generates and outputs the non-low feature condition result to the control circuit 115 (step S315). Therefore, in this case, the control circuit 115 controls the optical sensor 105 not to switch from the operating mode to the rest mode, i.e., does not change the mode of the sensor.
[0022] In other embodiments, the detection circuit 115 may detect a directional change of the generated displacement data (ie, multiple directions of multiple motions occurring in the sensed multiple pixel images) to perform and implement the low feature detection. Figure 41 is an operation flow chart of the detection circuit 115 for performing low feature detection according to different embodiments of the present invention. In step S400, when the detection circuit 115 receives the sensed plurality of pixel images from the optical sensor 105, the detection circuit 115 starts and performs the low feature detection to receive the displacement (or motion) data reported by the optical sensor 105. In this example, in practice, the detection circuit 115 does not execute the feature extraction engine described above, but is used to receive the displacement data generated or reported by the optical sensor 105 to count the number of direction changes of the plurality of displacement data continuously generated by the optical sensor 105 to calculate and obtain a direction change count, as shown in step S405, without counting the total number of texture features of the sensed plurality of pixel images. Then, the detection circuit 115 may compare the direction change count with a second threshold TH2 (i.e., a specific direction threshold), and compare the surface feature count with the minimum feature count threshold, as shown in step S410. In other embodiments, when the plurality of motions occurring in the sensed plurality of pixel images have continuous direction switching, the detection circuit 110 may determine that the low feature detection indicates the low feature condition result.
[0023] It is worth noting that, ideally, when a user operates the optical navigation device 100, for example, as an optical mouse device, the user himself rarely vibrates the optical navigation device 100, so the displacement / motion data periodically reported to a computer device by the optical navigation device 100 does not frequently change the direction of movement. Therefore, if the accumulated direction change count during a specific time interval is greater than the second threshold TH2 and the accumulated surface feature count is between the minimum feature count threshold and the low feature count threshold TH1, the detection circuit 115 can determine that an abnormal condition such as a low surface feature condition has occurred, and thus can determine whether the surface feature count corresponds to a low feature condition (e.g., a low surface feature condition), and generate and output a low feature condition result to the control circuit 115 (step S415). Alternatively, if the surface feature count accumulated during the specific time interval is not less than the second threshold value TH2, the detection circuit 115 can determine that no abnormal situation has occurred, and can determine that the surface feature count corresponds to a non-low feature situation (or can be called a non-low surface feature situation) and generate and output a non-low feature situation result to the control circuit 115 (step S420). Therefore, in this case, the control circuit 115 will control the optical sensor 105 not to switch from the operating mode to the rest mode, that is, the mode of the sensor will not be changed.
[0024] Furthermore, in one example, when the number of changes in the multiple directions of the multiple movements during the specific time interval is greater than the specific direction threshold TH2 and the accumulated feature count is not between the minimum feature count threshold and the low feature count threshold TH1, the detection circuit 110 may determine that the low feature detection does not indicate a low feature condition result. In addition, in another example, when the number of changes in the multiple directions of the multiple movements during the specific time interval is not greater than the specific direction threshold TH2 and the accumulated feature count is between the minimum feature count threshold and the low feature count threshold TH1, the detection circuit 110 may determine that the low feature detection indicates a low feature condition result.
[0025] In addition, in one embodiment, the detection circuit 110 is used to perform the low feature detection by calculating a hysteresis value of multiple feature counts of multiple pixel images sensed during a specific time interval, such as an average value of the multiple values, by comparing the hysteresis value of the multiple feature counts with the minimum feature count threshold and by comparing the hysteresis value of the multiple feature counts with the low feature count threshold TH1.
[0026] Furthermore, in other embodiments, the length of the specific time interval may be flexibly adjusted and may also be replaced by other operations. Figure 5 is an operation flow chart of the detection circuit 115 performing low feature detection according to another different embodiment of the present invention. In step S500, when receiving the sensed plurality of pixel images from the optical sensor 105, the detection circuit 115 starts and performs the low feature detection to perform the operation of the feature extraction engine and receives the displacement / motion data reported by the optical sensor 105. In practice, the detection circuit 115 executes the feature extraction engine to extract a plurality of texture features from the sensed plurality of pixel images and counts the number of total texture features to generate or calculate a surface feature count. Then, the detection circuit 115 may compare the surface feature count with a specific threshold value TH1, as shown in step S505. If the surface feature count is less than the specific threshold value TH1, the detection circuit 115 may determine that the surface feature count corresponds to a low feature condition (or may be referred to as a low surface feature condition), and generate and output a low feature condition result to the control circuit 112, as shown in step S505. If the surface feature count is not less than the specific threshold TH1, the process proceeds to step S510.
[0027] In step S510, the detection circuit 115 counts the number of direction changes of the plurality of displacement data continuously generated by the optical sensor 105 to calculate a direction change number, and the detection circuit 115 counts and accumulates the number of the plurality of displacement data continuously generated by the optical sensor 105 to calculate and obtain a total sensor count. Then, in step S515, the detection circuit 115 compares the direction change count with the second threshold TH2 to determine whether a first condition is satisfied (the direction change count is greater than the second threshold TH2), and also compares the accumulated total sensor count with a third threshold TH3 to determine whether a second condition is satisfied (the accumulated total sensor count is less than the third threshold TH3).
[0028] If both the first condition and the second condition are met, that is, the direction change count is greater than the second threshold value TH2 and the accumulated total sensor count is less than the third threshold value TH3, the detection circuit 110 can determine that an abnormal situation has occurred, such as a low surface feature condition, and thus can determine that the surface feature count corresponds to a low feature condition (such as the low surface feature condition) and generate and output a low feature condition result to the control circuit 115 (step S520).
[0029] Alternatively, if either the first condition or the second condition is not satisfied, that is, one condition or both conditions are not satisfied, the detection circuit 115 can determine that no abnormal situation has occurred, and can determine that the surface feature count corresponds to a non-low feature condition (or can be called a non-low surface feature condition) and generate and output a non-low feature condition result to the control circuit 115 (step S525), so in this case the control circuit 115 will control the optical sensor 105 not to switch from the operating mode to the rest mode, that is, not to change the sensor mode. The value of the third threshold TH3 is set to be greater than the value of the second threshold TH2, however, this is not a limitation of the present invention. In addition, for example (but not limited to), when the accumulated total sensor count is still less than the third threshold TH3 and when the direction change count becomes greater than the second threshold TH2 but has not yet reached the value of the third threshold TH3, the detection circuit 110 can determine that a low feature condition has occurred.
[0030] In this way, when the optical navigation device 100 is in a stationary state and / or a low-characteristic condition, the optical navigation device 100 can effectively eliminate stationary cursor jitter. The present invention proposes changing the operating state of an optical sensor when a low-characteristic condition is detected. For example, when a low-characteristic condition is detected, the operating state will be changed from an operating mode to a rest mode. When the optical sensor is in the rest mode, no displacement calculation will be performed. On the contrary, the optical sensor will perform a wake-up check operation. The wake-up check operation is a test that only checks for changes in image attributes. That is, if the number of changes in image attributes exceeds a predefined threshold, the optical sensor will return to the operating mode. In addition, in the rest mode, since no displacement calculation is performed, no unnecessary motion results will be generated.
[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. An optical navigation device, comprising: an optical sensor, configured to operate in a running mode to sense a plurality of pixel images for displacement calculation; a detection circuit, coupled to the optical sensor, for performing low-feature detection on the sensed plurality of pixel images; as well as A control circuit is coupled to the detection circuit, and is used to control the optical sensor to switch from the operating mode to a rest mode when the low characteristic detection indicates a low characteristic condition result, wherein the optical sensor does not perform the displacement calculation in the rest mode.
2. The optical navigation device according to claim 1, wherein: The detection circuit is used to perform the low feature detection by comparing the sensed feature counts of the plurality of pixel images with a minimum feature count threshold and by comparing the feature counts with a low feature count threshold.
3. The optical navigation device according to claim 2, wherein: The detection circuit determines that the low feature detection indicates the low feature condition result when the feature count is between the minimum feature count threshold and the low feature count threshold.
4. The optical navigation device according to claim 1, wherein: The detection circuit performs the low feature detection by detecting multiple directions of multiple motions occurring in the sensed multiple pixel images.
5. The optical navigation device according to claim 4, wherein: The detection circuit determines that the low feature detection indicates the low feature condition result when a continuous direction switch of the plurality of motions occurs in the sensed plurality of pixel images.
6. The optical navigation device according to claim 4, wherein: When the number of changes in the multiple directions of the multiple movements during a specific time interval is greater than a specific direction threshold and the cumulative feature count is between the minimum feature count threshold and the low feature count threshold, the detection circuit determines that the low feature detection indicates the low feature condition result.
7. The optical navigation device according to claim 4, wherein: When the number of changes in the multiple directions of the multiple movements during a specific time interval is greater than a specific direction threshold and the cumulative feature count is not between the minimum feature count threshold and the low feature count threshold, the detection circuit determines that the low feature detection will not indicate the low feature condition result.
8. The optical navigation device according to claim 4, wherein: When the number of changes in the multiple directions of the multiple movements during a specific time interval is not greater than a specific direction threshold and the cumulative feature count is between the minimum feature count threshold and the low feature count threshold, the detection circuit determines that the low feature detection indicates the low feature condition result.
9. The optical navigation device according to claim 1, wherein: The detection circuit is used to perform the low feature detection by calculating hysteresis values of multiple feature counts of the multiple pixel images sensed during a specific time interval, by comparing the hysteresis values of the multiple feature counts with the minimum feature count threshold, and by comparing the hysteresis values of the multiple feature counts with a low feature count threshold.
10. An optical navigation method of an optical navigation device, comprising: Providing an optical sensor to operate in an operating mode to sense a plurality of pixel images for displacement calculation; Performing low feature detection on the sensed plurality of pixel images; as well as The optical sensor is controlled to switch from the operating mode to a rest mode when the low feature detection indicates a low feature condition result, wherein the optical sensor does not perform the displacement calculation in the rest mode.
11. The optical navigation method according to claim 10, further comprising: The low feature detection is performed by comparing the sensed feature counts of the plurality of pixel images to a minimum feature count threshold and by comparing the feature counts to a low feature count threshold.
12. The optical navigation method according to claim 11, further comprising: The low feature detection is determined to indicate the low feature condition result when the feature count is between the minimum feature count threshold and the low feature count threshold.
13. The optical navigation method according to claim 10, further comprising: The low feature detection is performed by detecting directions of motions occurring in the sensed pixel images.
14. The optical navigation method as claimed in claim 13, further comprising: The low feature detection is determined to indicate the low feature condition result when a continuous direction switch of the plurality of motions occurs in the sensed plurality of pixel images.
15. The optical navigation method according to claim 13, further comprising: When the number of changes in the multiple directions of the multiple motions during a specific time interval is greater than a specific direction threshold and the cumulative feature count is between the minimum feature count threshold and the low feature count threshold, it is determined that the low feature detection indicates the low feature condition result.
16. The optical navigation method according to claim 13, further comprising: When the number of changes in the multiple directions of the multiple motions during the specific time interval is greater than a specific direction threshold and the cumulative feature count is not between the minimum feature count threshold and the low feature count threshold, it is determined that the low feature detection does not indicate the low feature condition result.
17. The optical navigation method according to claim 13, further comprising: When the number of changes in the multiple directions of the multiple motions during a specific time interval is not greater than a specific direction threshold and the cumulative feature count is within the minimum feature count threshold and the low feature count threshold, it is determined that the low feature detection indicates the low feature condition result.
18. The optical navigation method according to claim 10, further comprising: The low feature detection is performed by calculating hysteresis values of a plurality of feature counts of the plurality of pixel images sensed during a specific time interval, by comparing the hysteresis values of the plurality of feature counts with the minimum feature count threshold, and by comparing the hysteresis values of the plurality of feature counts with a low feature count threshold.