Lens device and lens focusing method

Abstract

The invention discloses a lens device which comprises a circuit board, an actuator, a lens, a memory and a processor. The circuit board is provided with a temperature sensor and a photosensitive element, and the temperature sensor is used for sensing and obtaining environment temperature. The lens is arranged on the actuator and corresponds to the photosensitive element. The memory stores the compensation temperature and the compensation distance value. The processor is connected to the actuator, the temperature sensor and the memory. When the environment temperature is equal to the compensation temperature, the processor sequentially outputs a compensation control signal and an automatic focusing signal, and the compensation control signal controls the actuator to drive the lens to continuously move a compensation distance value relative to the photosensitive element, so that the lens moves from an initial position to a compensation position. The automatic focusing signal controls the actuator to drive the lens to move from a compensation position to a focusing position by a plurality of focusing steps, and the compensation position is located between the initial position and the focusing position.

Description

Technical Field

[0001] The invention relates to an optical device, in particular to a lens device and a lens focusing method. Background Art

[0002] With the development of technology, lens devices are increasingly used in personal electronic products, automotive fields, medical fields, etc. to obtain external images. For example, most computer devices (such as notebook computers or tablet computers) have lens devices to support functions such as photography, web video or face recognition.

[0003] However, when the lens device is in use, each electronic component inside it generates heat during operation, causing the temperature of the lens device to continue to rise, resulting in the position of the lens being shifted, thereby changing the focal length of the lens and affecting the clarity of the displayed image. Summary of the invention

[0004] In view of the above, in one embodiment, a lens device is provided, including a circuit board, an actuator, a lens, a memory and a processor. The circuit board has a temperature sensor and a photosensitive element, and the temperature sensor senses and obtains the ambient temperature. The actuator is arranged on the circuit board. The lens is arranged on the actuator and corresponds to the photosensitive element, and the lens is located at an initial position. The memory stores a compensation temperature and a compensation distance value corresponding to the compensation temperature. The processor is connected to the actuator, the temperature sensor and the memory. When the ambient temperature is equal to the compensation temperature, the processor sequentially outputs a compensation control signal and an autofocus signal, the compensation control signal controls the actuator to drive the lens to continuously move the compensation distance value relative to the photosensitive element, so that the lens moves from the initial position to the compensation position, and the autofocus signal controls the actuator to drive the lens to move a plurality of focus steps from the compensation position to a focus position, and the compensation position is located between the initial position and the focus position.

[0005] In another embodiment, a lens focusing method is provided, including sensing an ambient temperature with a temperature sensor; determining with a processor whether the ambient temperature is equal to a compensation temperature, wherein the compensation temperature corresponds to a compensation distance value; when the ambient temperature is equal to the compensation temperature, the processor outputs a compensation control signal, the compensation control signal controls an actuator to drive the lens to continuously move the compensation distance value relative to a photosensitive element, so that the lens moves from an initial position to a compensation position; and the processor outputs an autofocus signal, the autofocus signal controls the actuator to drive the lens to move a plurality of focus steps from the compensation position to a focus position, and the compensation position is located between the initial position and the focus position.

[0006] In summary, according to the lens device and lens focusing method of the embodiments of the present invention, when the ambient temperature changes to a compensation temperature, the processor first outputs a compensation control signal to control the actuator to drive the lens to move a compensation distance value continuously, and then the processor outputs an autofocus signal to control the actuator to drive the lens to move multiple focus steps for autofocusing, so that the lens device can automatically adjust its position for focusing when the temperature changes and greatly shorten the focusing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a three-dimensional diagram of an embodiment of the lens device of the present application.

[0008] Figure 2 It is an exploded perspective view of an embodiment of the lens device of the present application.

[0009] Figure 3 It is a cross-sectional view of an embodiment of the lens device of the present application.

[0010] Figure 4 1 is a hardware block diagram of an embodiment of the lens device of the present application.

[0011] Figure 5 It is the focus curve diagram of a known lens.

[0012] Figure 6 It is a flowchart of the steps of an embodiment of the lens focusing method of the present application.

[0013] Figure 7 It is a compensation diagram of an embodiment of the lens device of the present application.

[0014] Figure 8 It is a focus curve diagram of an embodiment of the lens device of the present application.

[0015] Fig. 9 It is a flowchart of the steps of another embodiment of the lens focusing method of the present application.

[0016] Explanation of symbols:

[0017] 1: Lens device;

[0018] 10: Circuit board;

[0019] 11: Processor;

[0020] 12: Temperature sensor;

[0021] 13: memory;

[0022] 14: photosensitive element;

[0023] 20: actuator;

[0024] 21: shaft hole;

[0025] 30: Lens

[0026] 40: hollow base;

[0027] 41: internal space;

[0028] 42: Open your mouth;

[0029] 50,51: focus curve;

[0030] A: optical axis;

[0031] P: initial position;

[0032] C: Compensation position;

[0033] F, F1: focus position;

[0034] S01~S07: steps. DETAILED DESCRIPTION

[0035] Figure 1 This is a three-dimensional diagram of an embodiment of the lens device of the present application. Figure 2 This is an exploded perspective view of an embodiment of the lens device of the present application. Figure 3 is a cross-sectional view of an embodiment of the lens device of the present application, Figure 4 FIG. 1 is a hardware block diagram of an embodiment of the lens device of the present application. Figures 1 to 3 As shown, the lens device 1 of this embodiment includes a circuit board 10, an actuator 20, a lens 30, a memory 13, and a processor 11. In some embodiments, the lens device 1 can be applied to various electronic products to obtain images around the electronic products. For example, the lens device 1 can be applied to electronic products such as mobile devices (such as smart phones, tablet computers, or notebook computers), automotive products (such as driving recorders, reversing imaging systems, or surround image systems), or cameras.

[0036] like Figures 1 to 3 As shown, the circuit board 10 has a temperature sensor 12 and a photosensitive element 14. In some embodiments, the photosensitive element 14 can be a charge-coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), or a complementary metal-oxide semiconductor active pixel sensor (CMOS Active pixel sensor). In some embodiments, the temperature sensor 12 can be a thermistor or a thermocouple, and the temperature sensor 12 is used to sense and obtain an ambient temperature.

[0037] like Figures 1 to 3As shown, the actuator 20 is disposed on the circuit board 10, and the lens 30 is disposed on the actuator 20 and is located at an initial position, and the position of the lens 30 corresponds to the position of the photosensitive element 14, so that the external light can be concentrated on the photosensitive element 14 after being incident from the lens 30, so that the photosensitive element 14 senses and obtains the external image.

[0038] In some embodiments, the actuator 20 may be a voice coil motor, a stepping motor or a piezo actuator. The actuator 20 is used to drive the lens 30 to move relative to the photosensitive element 14 to adjust the relative position of the lens 30 and the photosensitive element 14.

[0039] like Figures 1 to 3 As shown, the memory 13 stores at least one compensation temperature and the compensation distance value corresponding to the compensation temperature. For example, the memory 13 can store multiple compensation temperatures higher than normal temperature, such as multiple compensation temperatures including 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, etc. In addition, the memory 13 stores the corresponding compensation distance value for each compensation temperature, for example, the compensation distance value corresponding to 30 degrees is 9.35 micrometers (Micrometer, um), the compensation distance value corresponding to 35 degrees is 18.24 micrometers, and the compensation distance value corresponding to 40 degrees is 26.48 micrometers. In other words, the higher the compensation temperature, the larger the corresponding compensation distance value, and so on.

[0040] In some embodiments, the memory 13 may be a fixed or removable random access memory (RAM), a read-only memory (ROM), a flash memory, a hard disk or other similar devices or a combination of these devices.

[0041] like Figures 2 to 4 As shown, the processor 11 is connected to the actuator 20, the temperature sensor 12 and the memory 13, so that the processor 11 can obtain the ambient temperature sensed by the temperature sensor 12 and the compensation temperature and compensation distance values ​​stored in the memory 13, and the processor 11 can output a signal to control the actuator 20 to drive the lens 30 to move relative to the photosensitive element 14.

[0042] In some embodiments, the processor 11 may be a central processing unit (CPU) composed of a single core or multiple cores, or other programmable general-purpose or special-purpose microprocessor (Microprocessor), digital signal processor (Digital Signal Processor, DSP), programmable controller, application specific integrated circuits (Application Specific Integrated Circuits, ASIC), programmable logic device (Programmab1 e ​​Logic Device, PLD) or other similar devices.

[0043] In some embodiments, the processor 11 may be connected to the actuator 20, the temperature sensor 12, and the memory 13 via wired or wireless means. In addition, the processor 11 may also be directly or indirectly connected to the actuator 20, the temperature sensor 12, and the memory 13.

[0044] Figure 5 is the focus curve of a known lens, Figure 6 This is a flowchart of the steps of an embodiment of the lens focusing method of this application. First, please refer to Figure 5 As shown, the auto focus method of the conventional lens is mainly to control the lens to move to multiple positions by multiple steps, and the lens will stay for a period of time when moving to different positions, and calculate the focus value corresponding to each position through an algorithm to know the clarity of the image currently captured by the lens at each position, wherein the position where the lens has the highest image clarity is the focus position.

[0045] For example, if Figure 5 As shown, when the ambient temperature does not change, it is known that the lens will generate a focus curve 50 during the autofocus process. In this figure, the X-axis represents the Dac value corresponding to the lens position (here 0 to 27 Dac), and the Y-axis represents the focus value (here 0.1 to 0.9), wherein the focus curve 50 shows that the maximum focus value is 0.8, and the maximum focus value corresponds to the lens position, i.e., the focus position F. Assuming that the known moving step of the lens during the autofocus process is 1 Dac, it takes 15 steps for the lens to move from the initial position P to the focus position F, and each step must be stopped and the focus value calculated.

[0046] like Figure 6As shown, the lens focusing method of the embodiment of the present application includes steps S01 to S04. The hardware structure mentioned below can be referred to the lens device 1 disclosed above, and is described here first. In step S01, the temperature sensor 12 is used to sense an ambient temperature, wherein the ambient temperature may refer to the temperature of the environment where the temperature sensor 12 is located. For example, please refer to Figure 2 and Figure 3 As shown, in this embodiment, a hollow base 40 is disposed on the circuit board 10, and the hollow base 40 has an internal space 41, and one end of the lens 30 is adjacent to the internal space 41, and the temperature sensor 12 and the photosensitive element 14 are both located in the internal space 41, and the ambient temperature is the temperature of the internal space 41. In some embodiments, the temperature sensor 12 can also be disposed outside the hollow base 40 to sense the ambient temperature around the lens 30.

[0047] In addition, if Figure 2 and Figure 3 As shown, in the present embodiment, the processor 11 and the memory 13 are both disposed outside the hollow base 40, but this is not limited to this. In some embodiments, at least one of the processor 11 and the memory 13 may also be disposed in the internal space 41 of the hollow base 40, or the processor 11 and the memory 13 may not be disposed on the circuit board 10.

[0048] like Figure 6 As shown, after step S01, step S02 may be performed: the processor 11 determines whether the ambient temperature is equal to the compensation temperature. Figures 1 to 4 As shown, during the use of the lens device 1, each electronic component inside it generates heat during operation, causing the temperature sensor 12 to detect a gradual increase in the ambient temperature. The processor 11 can determine whether the ambient temperature reaches a certain compensation temperature stored in the above-mentioned memory 13. If so, step S03 is performed. If not, the processor 11 continues to make judgments.

[0049] like Figure 6 As shown, when the ambient temperature is equal to the compensation temperature, step S03 is performed first: the processor 11 outputs a compensation control signal. The compensation control signal can control the actuator 20 to drive the lens 30 to continuously move the compensation distance value relative to the photosensitive element 14, so that the lens 30 moves from the initial position P to the compensation position C.

[0050] For more details, please refer to Figure 5 and Figure 7 As shown, when the ambient temperature increases due to the operation of the lens device 1, the focus curve 50 will shift and become another focus curve 51 (such as Figure 7As shown in FIG. 1 , the original focus position F is changed to the focus position F1 which is further away from the initial position P of the lens 30, resulting in a longer focus time for the lens 30. For example, in the present embodiment, assuming that the moving step of the lens 30 is 1 Dac, when the ambient temperature rises, the lens 30 needs 22 steps to move from the initial position P to the focus position F1, which is more than the 15 steps required for the initial position P to move to the focus position F. Therefore, in terms of the traditional focus method, the increase in ambient temperature will increase the focus movement time of the lens 30.

[0051] Based on the above, please refer to Figures 3 to 8 As shown, in step S03 of the present embodiment, assuming that when the lens 30 is at the initial position P, the ambient temperature sensed by the temperature sensor 12 is 25 degrees. When the ambient temperature rises due to the operation of the lens device 1 and reaches the compensation temperature stored in the memory 13 (such as the above-mentioned 30 degrees), the processor 11 outputs a compensation control signal. The compensation control signal can immediately control the actuator 20 to drive the lens 30 to continuously move the compensation distance value corresponding to the compensation temperature (such as the above-mentioned 9.35 microns corresponding to the 30 degrees), so that the lens 30 moves from the initial position P to the compensation position C first, wherein the compensation position C can be the starting position of the above-mentioned other focus curve 51 (such as Figure 7 As shown) or other positions between the starting position and the focus position F1. Figure 7 As shown, the above “uninterrupted movement” means that the lens 30 does not stop during the process of moving from the initial position P to the compensation position C, so the focus value of the lens 30 during the movement is not calculated.

[0052] Then, if Figure 6 As shown, step S04 is performed after step S03: the processor 11 outputs an auto-focus signal, which can control the actuator 20 to drive the lens 30 to move from the compensation position C to the focus position F1 by multiple focus steps, and the compensation position C is located between the initial position and the focus position F1. Figure 8 As shown, compared with the known auto-focusing process, the starting position of the auto-focusing process of the lens 30 of this embodiment is changed from the initial position P to the compensation position C (such as Figure 8 Therefore, assuming that the focusing step of the lens 30 during the autofocus process is 1 Dac, when the ambient temperature rises, it only takes 15 steps for the lens 30 to move from the initial position P to the focusing position F1, thereby greatly reducing the time for staying and calculating the focus value. For example, assuming that the focusing time of the lens is known to be 0.3 seconds, the total focusing time of the lens 30 in the embodiment of the present application (i.e., the time for executing step S03 and step S04) can be reduced to at least 0.2 seconds, so that the lens device 1 can automatically adjust the position for focusing when the temperature changes and greatly reduce the focusing time.

[0053] Specifically, since in step S03, the lens 30 moves from the initial position P to the compensation position C in a "continuous movement" and in step S04, the lens 30 moves from the compensation position C to the focus position F1 in a "step-by-step movement", the average speed of the lens 30 during the movement from the initial position P to the compensation position C is greater than the average speed during the movement from the compensation position C to the focus position F1, which can greatly reduce the focus movement time of the lens 30 from the initial position P to the focus position F1.

[0054] In addition, please check Figure 3 and Figure 6 As shown, in this embodiment, one side of the hollow base 40 is fixed on the circuit board 10, and the other side of the hollow base 40 has an opening 42. The position of the photosensitive element 14 corresponds to the position of the opening 42. The actuator 20 is arranged on the side of the hollow base 40 having the opening 42, and the actuator 20 is annular and has an axial hole 21, and the axial hole 21 is connected to the opening 42 of the hollow base 40. The lens 30 is assembled in the axial hole 21 of the actuator 20 to cover the opening 42 of the hollow base 40, wherein the lens 30 has an optical axis A. In the above steps S03 and S04, the actuator 20 drives the movement of the lens 30 along the direction of the optical axis A.

[0055] Fig. 9 This is a flowchart of another embodiment of the lens focusing method of the present application. Fig. 9 As shown, in this embodiment, before the above step S01, the processor 11 may enter a sleep mode (step S05). For example, the processor 11 may enter a sleep mode or a wake-up mode. For example, the processor 11 may be set to enter the sleep mode when the lens device 1 is not used for a predetermined time (such as 1 minute or 5 minutes). When the lens device 1 receives a working signal, the processor 11 switches from the sleep mode to the wake-up mode. Alternatively, when the lens device 1 is applied to a notebook computer, the processor 11 may enter the sleep mode when the notebook computer is closed to save energy. When the notebook computer is opened, the processor 11 switches from the sleep mode to the wake-up mode.

[0056] like Fig. 9 As shown, after the processor 11 enters the sleep mode (step S05), the temperature sensor 12 continuously detects and obtains the ambient temperature (step S01), and the processor 11 continuously receives the ambient temperature sensed by the temperature sensor 12 (step S06) to obtain the current ambient temperature at any time.

[0057] like Fig. 9As shown, after step S06, it is then determined whether the processor 11 enters the wake-up mode (step S07). For example, if the lens device 1 does not receive the working signal, the processor 11 continues to be in the sleep mode, so that the temperature sensor 12 continues to detect and obtain the ambient temperature. When the processor 11 enters the wake-up mode from the sleep mode, the processor 11 executes the above steps S02 to S04. That is, when the processor 11 enters the sleep mode, it does not determine whether the ambient temperature is equal to the compensation temperature, so as to reduce the energy consumption of the processor 11.

[0058] In addition, if Fig. 9 As shown, in the present embodiment, when the processor 11 is in the sleep mode, the temperature sensor 12 continuously detects and obtains the ambient temperature in advance, rather than waiting until the processor 11 enters the wake-up mode to start sensing the ambient temperature. Therefore, when the processor 11 enters the wake-up mode, it can immediately compare the latest ambient temperature to determine whether it is equal to the compensation temperature. When the ambient temperature is equal to the compensation temperature, the compensation control signal and the auto-focus signal can be output in sequence immediately, so that the lens device 1 can quickly complete the focusing, thereby further reducing the focusing time.

[0059] In summary, according to the lens device 1 and the lens focusing method of the above-mentioned embodiment of the present application, when the ambient temperature of the processor 11 is equal to the compensation temperature, the processor 11 first outputs a compensation control signal to control the actuator 20 to drive the lens 30 to continuously move the compensation distance value relative to the photosensitive element 14, and then the processor 11 outputs an autofocus signal to control the actuator 20 to drive the lens 30 to move multiple focus steps for autofocusing, so that the lens device 1 can automatically adjust its position for focusing when the temperature changes and greatly reduce the focusing time.

[0060] Although the technical content of this application has been disclosed as above in the form of a preferred embodiment, it is not intended to limit this application. Any slight changes and modifications made by any technical personnel in this field without departing from the spirit of this application should be included in the scope of this application. Therefore, the scope of protection of this application shall be based on the scope of the attached patent application.

Claims

1. A lens device, characterized in that: include: The circuit board has a temperature sensor and a photosensitive element, wherein the temperature sensor senses and obtains the ambient temperature; an actuator, disposed on the circuit board; A lens, disposed on the actuator and corresponding to the photosensitive element, and the lens is located at an initial position; A memory, storing a compensation temperature and a compensation distance value corresponding to the compensation temperature; as well as a processor connected to the actuator, the temperature sensor and the memory; When the ambient temperature is equal to the compensation temperature, the processor sequentially outputs a compensation control signal and an autofocus signal, wherein the compensation control signal controls the actuator to drive the lens to continuously move the compensation distance value relative to the photosensitive element so that the lens moves from the initial position to the compensation position, and the autofocus signal controls the actuator to drive the lens to move a plurality of focus steps from the compensation position to the focus position, and the compensation position is located between the initial position and the focus position.

2. The lens device according to claim 1, wherein: The processor can selectively enter a sleep mode or a wake-up mode. When the processor is in the sleep mode, the temperature sensor continuously detects and obtains the ambient temperature. When the processor is in the wake-up mode, the processor determines whether the ambient temperature is equal to the compensation temperature.

3. The lens device according to claim 1, wherein: A hollow base is arranged on the circuit board, and the hollow base has an internal space. The temperature sensor and the photosensitive element are located in the internal space, and the ambient temperature is the temperature of the internal space.

4. The lens device according to claim 1, wherein: An average speed at which the initial position moves to the compensation position is greater than an average speed at which the compensation position moves to the focus position.

5. The lens device according to claim 1, wherein: The actuator is a voice coil motor.

6. A lens focusing method, characterized in that: include: (a) obtaining the ambient temperature by using a temperature sensor; (b) determining, by a processor, whether the ambient temperature is equal to a compensation temperature, wherein the compensation temperature corresponds to a compensation distance value; (c) when the ambient temperature is equal to the compensation temperature, the processor outputs a compensation control signal, wherein the compensation control signal controls the actuator to drive the lens to continuously move the compensation distance value relative to the photosensitive element, so that the lens moves from an initial position to a compensation position; as well as (d) The processor outputs an auto-focus signal, wherein the auto-focus signal controls the actuator to drive the lens to move from the compensation position to a focus position by a plurality of focus steps, and the compensation position is located between the initial position and the focus position.

7. The lens focusing method according to claim 6, wherein: The processor can selectively enter a sleep mode or a wake-up mode. Before step (a), the processor enters the sleep mode. Before step (b), the processor continuously receives the ambient temperature. During step (b), the processor has entered the wake-up mode from the sleep mode.

8. The lens focusing method according to claim 6, wherein: The temperature sensor and the photosensitive element are located in the inner space of the hollow base, and the ambient temperature is the temperature of the inner space.

9. The lens focusing method according to claim 6, wherein: An average speed at which the initial position moves to the compensation position is greater than an average speed at which the compensation position moves to the focus position.

10. The lens focusing method according to claim 6, wherein: The actuator is a voice coil motor.

Images