Exposure adjusting method of optical mouse

Abstract

The invention relates to an exposure adjusting method of an optical mouse, which comprises the following steps of: after executing exposure, determining a corresponding adjusting value and an image quality index through a captured reflection image, then adjusting exposure time and an exposure starting brightness value, and referring to the characteristic quantity of a working surface applied by the optical mouse by referring to the image quality index. The exposure time is indirectly influenced by a method of adjusting the exposure starting brightness value, and then the next exposure is executed, so that the effects of saving electricity and energy can be achieved on the premise of maintaining the accuracy.

Description

Technical Field

[0001] This invention relates to a control method for an optical mouse, and more particularly to a method for controlling the exposure adjustment of optics. Background Technology

[0002] Generally, optical mice are controlled by sliding their bottom surface across a work surface. An optical mouse has a light source that shines towards the work surface and receives the reflected image, thereby determining the mouse's movement trajectory and speed, as well as its operational status. Therefore, controlling the exposure time of the light source directly affects the quality of the received reflected image, and consequently, the judgment of the mouse's operational status. While a longer exposure time can maintain accuracy, it also increases the optical mouse's power consumption and shortens the lifespan of the light source. Therefore, current optical mice adjust their exposure time according to usage conditions to maintain accuracy while achieving energy efficiency and durability.

[0003] Existing optical mice set a target brightness value. When receiving each frame of reflected image, they observe the difference between the current brightness value and the target brightness value to determine how to adjust the exposure time. However, under the existing adjustment mechanism, the brightness value is mainly affected by the color of the working surface. Therefore, the exposure time adjusted to the same color working surface will fall within a similar range. But even working surfaces of the same color may have different surface features, resulting in different quality of reflected images. For example, a smooth black surface (acrylic desktop) and a rough black surface (mouse pad) do not require the same exposure time, even if they are the same color. Therefore, there is still room for improvement in the existing method. Summary of the Invention

[0004] In view of this, the present invention improves the exposure adjustment method of the existing optical mouse in order to adjust the exposure time more efficiently, thereby achieving the purpose of saving power and durability.

[0005] To achieve the aforementioned objective, this invention provides an exposure adjustment method for an optical mouse, comprising the following steps:

[0006] a. Perform an exposure based on a first exposure time and capture a first reflection image;

[0007] b. Determine a first reflection brightness value based on the first reflected image and a first initial exposure brightness value;

[0008] c. Determine an adjustment value and an image quality index based on the first reflected brightness value and the first reflected image;

[0009] d. Adjust the first exposure time to a second exposure time based on the adjustment value, and adjust the first initial exposure brightness value to a second initial exposure brightness value based on the image quality index;

[0010] e. Perform exposure according to the second exposure time and capture a second reflected image.

[0011] The advantage of this invention is that by referring to image quality indicators to further adjust the initial exposure brightness value, it can better correspond to the working surface conditions applied, thereby indirectly affecting the exposure time, thus combining accuracy with energy saving and durability. Attached Figure Description

[0012] Figure 1 This is a flowchart of the present invention;

[0013] Figure 2 This is a flowchart illustrating one embodiment of some steps of the present invention;

[0014] Figure 3 This is a flowchart illustrating one embodiment of some steps of the present invention. Detailed Implementation

[0015] The following description, in conjunction with the accompanying drawings and embodiments of the present invention, further illustrates the technical means employed by the present invention to achieve its intended purpose.

[0016] Please see Figure 1 As shown, the exposure adjustment method for an optical mouse of the present invention includes the following steps: performing exposure (S10): exposing the light source of the optical mouse according to a set exposure time; capturing a reflected image (S20): after the light emitted by the light source of the optical mouse illuminates the working surface applied by the optical mouse, the receiving component of the optical mouse receives the reflected image from the working surface after the light illumination; determining a reflected brightness value (S30): calculating and determining a reflected brightness value based on the captured reflected image and the set initial exposure brightness value; determining an adjustment value and an image quality index (S40): the calculation unit determines an adjustment value and an image quality index based on the received reflected brightness value and the reflected image; adjusting the exposure time and initial exposure brightness value (S50): adjusting the exposure time according to the adjustment value, adjusting the initial exposure brightness value according to the image quality index, returning to step S10 to perform exposure with the adjusted exposure time, and performing the next step S30 with the adjusted initial exposure brightness value.

[0017] In one embodiment, during exposure, an exposure is performed based on a first exposure time, and a first reflectance value is determined based on a first initial exposure brightness value. This is subsequently adjusted to a second initial exposure brightness value and a second exposure time. The next exposure is then performed based on the second exposure time, and a second reflectance value is determined based on the second initial exposure brightness value. The terms "first" and "second" are merely used to indicate the sequence for easy identification before and after adjustment, and are not intended to specify particular initial exposure brightness values, exposure times, or reflectance brightness values.

[0018] Generally, after exposure, the reflected image of an optical mouse is set to reach a target brightness value to ensure that the captured reflected image has sufficient features for subsequent judgment. Since the preset exposure time may not suit actual usage, as mentioned in the prior art, the exposure time is adjusted according to the brightness value of the reflected image to ensure that the subsequent reflected image reaches the target brightness value. However, if the image quality of the reflected image is good, it can provide sufficient features for subsequent judgment before reaching the target brightness value. Therefore, in addition to adjusting the exposure time, the initial exposure brightness value can also be adjusted by referring to image quality indicators to indirectly adjust the exposure time. The initial exposure brightness value is used to calculate the reflected image brightness value received by the receiving unit. After adjusting the initial exposure brightness value, the brightness of the reflected image is then provided to the calculation unit as the basis for calculating the subsequent exposure time adjustment value, thereby indirectly adjusting the exposure time. The aforementioned calculation of the initial exposure brightness value and the brightness of the reflected image can be processed by hardware (e.g., analog-to-digital converter, DAC) or software. More specifically, assuming the optical mouse's initial exposure brightness value is 0 units when initially detecting an image, and the target brightness value of the reflected image is 100 units, if the exposure starts from the initial exposure brightness value of 0 units, it will take 10 units of exposure time for the brightness of the reflected image to meet the condition of the target brightness value of 100 units. If the image quality is better, the initial exposure brightness value can be set higher, for example, to 20 units. Since the initial exposure brightness value starts from 20 units, the brightness of the reflected image can reach the same target brightness value of 100 units after about 8 units of exposure time (less than 10 units of exposure time). The computing unit can then extract enough features from the reflected image in a shorter exposure time for subsequent judgment.

[0019] The initial exposure brightness value is determined by at least one of a reference value and a compensation value. In one embodiment, the initial exposure brightness value is determined by a reference value and a compensation value. Before step S10 is executed, the reference value is determined based on a reference index. The reference index may be the resolution (DPI, Dots Per Inch) set by the optical mouse, generally referred to as sensitivity. For example, the user can set the resolution of the optical mouse in the operating system or on the shortcut key of the optical mouse. If a higher resolution is required, more exposure time is needed for the obtained reflected image to reach a value close to the target brightness value so that sufficient feature quantity can be obtained from the reflected image for subsequent judgment. Therefore, the reference value is initially set to a lower value, that is, the initial exposure brightness value is set to a position close to or equal to the actual brightness value of 0. Conversely, if a lower resolution is required, it is sufficient to make a judgment under the condition of obtaining relatively less feature quantity. The exposure time for the obtained reflected image to reach a value close to the target brightness value is thus reduced. Therefore, the initial exposure brightness value is set to a position greater than or far from the actual brightness value of 0 at the beginning. Therefore, adjusting the initial exposure brightness value indirectly affects the exposure time, which in turn affects the power efficiency and durability of the optical mouse. It should be noted that when the reference indicators and image quality indicators are within specific values ​​or ranges, both the baseline and compensation values ​​can be zero, depending on system settings or subsequent feedback.

[0020] In one embodiment, the image quality index determined in step S30 may be determined by the following methods, but not limited to: the brightness value of each pixel in the reflected image, such as the average brightness value of each pixel, the average brightness value minus the initial exposure brightness value, the standard deviation of the brightness value of each pixel, or the contrast of the brightness value of each pixel (e.g., using the Laplacian Operator to perform edge detection to obtain contrast and pattern boundaries).

[0021] In one embodiment, in step S50, the compensation value is adjusted based on the image quality index. Please refer to [link to relevant documentation]. Figure 2As shown, firstly, it is determined whether the reflected image comes from a special working surface based on the image quality index (S511). If so, the compensation value is determined to be a preset maximum value or a preset minimum value (S512). The special working surface can be a working surface with extremely low brightness (such as a completely black surface), in which case the compensation value is set to the maximum value, or a working surface with extremely high brightness (such as a completely white surface), in which case the compensation value is set to the minimum value. If step S511 determines no, then the compensation value is further determined based on the image quality index. For example, the image quality index is compared with a first image threshold value (S513). If the image quality index is less than the first image threshold value, the compensation value is adjusted to decrease by 1 unit (S514). If the image quality index is greater than or equal to the first image threshold value, it is further compared with a second image threshold value (S515). If the image quality index is greater than the second image threshold value, the compensation value is adjusted to increase by 1 unit (S516). If the image quality index is less than or equal to the second image threshold value, it means that the image quality index is between the first image threshold value and the second image threshold value, and the compensation value is not adjusted (S517). The unit used to adjust the compensation value can be any value greater than 0. For example, if 1 unit represents the value 3, then increasing or decreasing by 1 unit represents a compensation value of +3 or -3. Furthermore, if the second image threshold value is greater than the first image threshold value, and the image quality index is less than the first image threshold value, it means the image quality is lower than expected. In this case, the compensation value is reduced to decrease the initial exposure brightness value, thereby indirectly lengthening the exposure time. Conversely, if the image quality index is greater than the second image threshold value, it means the image quality is higher than expected. In this case, the compensation value is increased to increase the initial exposure brightness value, thereby indirectly shortening the exposure time. In one embodiment, the adjusted compensation value must be between the aforementioned preset maximum value and preset minimum value, meaning the adjusted compensation value does not exceed the preset maximum value or is not less than the preset minimum value.

[0022] In one embodiment, the adjusted initial exposure brightness value can be directly calculated using the adjusted compensation value. In another embodiment, it can be further determined whether the aforementioned reference index has changed (S518). If the reference index has changed, an adjusted baseline value is determined based on the changed reference index, and the adjusted initial exposure brightness value is calculated using the adjusted baseline value and the adjusted compensation value (S501). If the reference index has not changed, the adjusted initial exposure brightness value is calculated using the original baseline value and the compensation value (S502). For example, the change in the reference index may be due to the user modifying the resolution setting.

[0023] In one embodiment, the initial exposure brightness value is calculated using the following steps in steps S40 and S50, and the exposure time is adjusted using this adjustment value. Please refer to [link to relevant documentation]. Figure 3As shown, first calculate the difference Diff(S421) between the obtained reflected luminance value and the target luminance value in S30, then determine the adjustment value △ based on this difference Diff, and finally adjust the exposure time according to this adjustment value △ (S503). The method of determining the adjustment value △ based on the difference Diff can be: compare the difference Diff with a luminance threshold value (S423), and determine the adjustment value based on the comparison result (S424). For example, set i range values corresponding to i adjustment values △, and compare them with the difference Diff. For example, Diff < -20, -20 ≤ Diff < -15, -15 ≤ Diff < -10, -10 ≤ Diff < -5, -5 ≤ Diff < 5, 5 ≤ Diff < 10, 10 ≤ Diff < 15, 15 ≤ Diff < 20, 20 < Diff, which respectively correspond to the adjustment values △ = 6, 4, 2, 1, 0, -1, -2, -4, or -6.

[0024] In summary, the present invention adjusts the initial exposure luminance value through the image quality index obtained from the reflected image, thereby indirectly affecting the length of the exposure time. Coupled with the direct adjustment of the exposure time after comparing the luminance values, it can maintain a high recognition accuracy for the patterns or textures on the working surface of the optical mouse, thereby achieving the purpose of effective power saving and energy conservation.

[0025] The above description is only an embodiment of the present invention and does not impose any formal limitation on the present invention. Although the present invention has been disclosed as above by way of examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes or modifications to equivalent embodiments within the scope of the technical solution of the present invention without departing from the technical solution of the present invention. However, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An exposure adjustment method for an optical mouse, characterized in that, Includes the following steps: a. Perform an exposure based on a first exposure time and capture a first reflection image; b. Determine a first reflection brightness value of the first reflection image based on the first reflection image and a first initial exposure brightness value; c. Determine an adjustment value and an image quality index based on the first reflected brightness value and the first reflected image; d. Adjust the first exposure time to a second exposure time based on the adjustment value, and adjust the first initial exposure brightness value to a second initial exposure brightness value based on the image quality index; and e. Perform exposure according to the second exposure time and capture a second reflected image, and determine a second reflected image value based on the second reflected image and the second initial exposure brightness value.

2. The exposure adjustment method for an optical mouse as described in claim 1, characterized in that: The first exposure value includes a first compensation value; In step e, the first compensation value is adjusted to a second compensation value based on the image quality index, and the second initial exposure brightness value is calculated using the second compensation value.

3. The exposure adjustment method for an optical mouse as described in claim 1, characterized in that: The initial exposure value is determined based on a first reference value and a first compensation value; Before step a, perform the following steps: a0. Determine the first benchmark value based on a reference index; In step e, the first compensation value is adjusted to a second compensation value based on the image quality index, and the second initial exposure brightness value is calculated using the first reference value and the second compensation value.

4. The exposure adjustment method for an optical mouse as described in claim 3, characterized in that, In step e, it is determined whether the reference index has changed; if the reference index has changed, a second reference value is determined based on the changed reference index, and the second initial exposure brightness value is calculated using the second reference value and the second compensation value. If the reference index remains unchanged, the second initial exposure brightness value is calculated based on the first benchmark value and the second compensation value.

5. The exposure adjustment method for an optical mouse as described in claim 3 or 4, characterized in that, This reference metric refers to the resolution set for this optical mouse.

6. The exposure adjustment method for an optical mouse as described in any one of claims 2 to 4, characterized in that, The steps for adjusting the first compensation value to the second compensation value are as follows: e01. Determine whether the second reflected image originates from a special working surface based on the image quality index; e02. If step e01 determines that it is yes, then the second compensation value is determined to be a preset maximum value or a preset minimum value; e03. If step e01 determines no, then the first compensation value is adjusted to the second compensation value based on the image quality index.

7. The exposure adjustment method for an optical mouse as described in claim 6, characterized in that, Step e03 includes the following steps: e031. Determine whether the image quality index is less than a first image threshold value; e032. If step e031 determines that it is yes, then the first compensation value is reduced by 1 unit to form the second compensation value; e033. If step e031 is incorrect, further determine whether the image quality index is greater than a second image threshold value. e034. If step e033 determines that it is yes, then it is decided that the first compensation value is increased by 1 unit to form the second compensation value; e035. If step e033 determines no, then the first compensation value remains unchanged and is used to form the second compensation value.

8. The exposure adjustment method for an optical mouse as described in any one of claims 1 to 4, characterized in that, In step c, the adjustment value is calculated using the following steps: c01. Calculate the difference between the first reflected brightness value and the brightness value of a target; c03. The adjustment value is determined based on this difference.

9. The exposure adjustment method for an optical mouse as described in claim 8, characterized in that, In step c03, i range values ​​are set to correspond to i adjustment values. When the difference falls on the x-th range value, the x-th adjustment value corresponding to the x-th range value is determined as the adjustment value. Here, i is a positive integer greater than 1, and x is a variable less than i.

10. The exposure adjustment method for an optical mouse as described in any one of claims 1 to 4, characterized in that, Based on the second reflection image captured in step e, steps b, c, and d are repeated.

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