CN210093336U - Filter device of camera and camera - Google Patents

Abstract

The utility model provides a filter device for a camera and a camera. The filter device provided by the present invention includes a filter assembly, which has a rotation axis deviated from the imaging field of view of the camera, and includes a first filter element and a second filter element arranged around the rotation axis, wherein , the first filter element cuts off infrared light, and the second filter element transmits infrared light; the driving component is connected to the filter component in a driving manner, so that the first filter element and the second filter element follow any The rotation of the filter assembly alternately blocks the imaging field of view. When the filter assembly is rotated by the drive assembly, the first filter element and the second filter element can alternately block the imaging field of view, so the camera using the filter device can realize alternate imaging with infrared light and visible light.

Description

Camera filter device and camera

technical field

The utility model relates to the field of imaging, in particular to a filter device for a video camera and a video camera.

Background technique

In some surveillance scenarios, the camera needs to be exposed to visible light and infrared light separately for imaging.

Therefore, how to make the camera use visible light and infrared light to expose and form images respectively has become a technical problem to be solved in the prior art.

Utility model content

In view of this, an embodiment of the present invention provides a filter device for a camera, including:

A filter assembly having a rotation axis deviated from the imaging field of view of the camera, and comprising a first filter element and a second filter element arranged around the rotation axis, wherein the first filter element is sensitive to infrared light cut off, the second filter element transmits infrared light;

A driving assembly is in driving connection with the filter assembly, so that the first filter element and the second filter element alternately block the imaging field of view with the rotation of the filter assembly.

Optionally, the first filter element cuts off infrared light and transmits visible light, and the second filter element transmits infrared light and cuts off visible light, or transmits infrared light and transmits visible light.

Optionally, the filter assembly is in the shape of a circular plane, and the first filter element and the second filter element are in the shape of a fan plane.

Optionally, the central angles of the first filter element and the second filter element are both 180 degrees.

Optionally, the central angle of one of the first filter element and the second filter element is less than 180 degrees, and the center of the other of the first filter element and the second filter element The angle is greater than 180 degrees.

Optionally, the filter assembly includes a plurality of first filter elements and a plurality of second filter elements, wherein the number of the first filter elements and the number of the second filter elements are the same , and the first filter element and the second filter element are alternately arranged.

Optionally, the number of the first filter elements or the second filter elements is an even number.

Optionally, the number of the first filter element or the second filter element is 2, 4 or 8.

Optionally, the central angle of the first filter element is less than 90 degrees, and the central angle of the second filter element is less than 90 degrees.

Optionally, the drive assembly includes a stepper motor or a DC motor.

Another embodiment of the present invention provides a camera, comprising:

lens mount;

a lens fixedly mounted on the lens holder;

a sensing module, which is fixedly installed on the lens holder and includes an image sensor, wherein the image sensor is arranged in the imaging field of view formed by the external light entering the camera through the lens;

The filter device as described above, wherein the filter component of the filter device is disposed between the lens and the sensing module, so that the image sensor alternately generates the imaging field of view by the image sensor. A first image when the first filter element is blocked, and a second image when the imaging field of view is blocked by the second filter element.

Optionally, the driving assembly is fixedly mounted on the lens holder by a fastener, wherein the rotation axis of the driving assembly is aligned with the rotation axis of the filter assembly.

Optionally, the first filter element and the second filter element alternately form a projection covering the image sensor within the imaging field of view.

Optionally, the lens mount includes a base, a support plate, and a mounting plate, wherein the base, the support plate, and the mounting plate form an accommodating space, and the lens portion is disposed in the accommodating space, In addition, the first filter element and the second filter element pass through the accommodating space alternately with the rotation of the filter assembly.

Optionally, the sensing module further includes an electronic shutter, and the first filter element or the second filter element is within the imaging field of view during the period from when the electronic shutter is opened to when the electronic shutter is closed. The resulting projection always covers the image sensor.

Optionally, the camera further comprises: a light-interrupting sensor, the light-interrupting sensor comprising a light receiver and a light transmitter;

The optical filter assembly is rotatably disposed between the optical receiver and the optical transmitter, wherein one of the first optical filter element and the second optical filter element transmits the optical transmitter light, the other one of the first filter element and the second filter element cuts off the light of the optical transmitter;

When the optical filter assembly rotates, the optical receiver generates a voltage jump signal in response to successful and unsuccessful reception of the light of the optical transmitter, which is used to determine that the image sensor is receiving the first The light transmitted by the filter element or the light transmitted by the second filter element is received.

Based on the above embodiment, when the filter component of the filter device is driven to rotate by the driving component, the first filter element and the second filter element can be used to alternately block the imaging field of view, Since the first filter element cuts off infrared light, the second filter element transmits infrared light, and the image sensor alternately generates a first image when the imaging field of view is blocked by the first filter element, and the second image when the imaging field of view is blocked by the second filter element, so the camera using the filter device can realize alternate imaging with infrared light and visible light.

Description of drawings

The following drawings merely illustrate and explain the present utility model schematically, and do not limit the scope of the present utility model:

FIG. 1 is a schematic diagram of the assembly structure of an imaging assembly in one embodiment;

FIG. 2 is a schematic diagram of an exploded structure of the imaging assembly shown in FIG. 1;

FIG. 3 is a schematic diagram of the control architecture of the imaging component as shown in FIG. 1 applied to the camera;

4a to 4d are schematic diagrams of exposure cycles of the imaging assembly shown in FIG. 1;

FIG. 5 is a schematic diagram of an example of a filter color wheel in which the imaging assembly as shown in FIG. 1 supports night vision shooting of a camera;

6 is a schematic diagram of the signal timing in the example shown in FIG. 5;

FIG. 7 is a schematic diagram of an example of a filter color wheel in which the imaging assembly as shown in FIG. 1 supports spectral acquisition of a camera;

8 is a schematic diagram of the signal timing in the example shown in FIG. 7;

FIG. 9 is a schematic diagram of the layout principle of the color filter disk of the imaging assembly as shown in FIG. 1;

10 is a schematic diagram of an example of an extension of a filter color wheel in which the imaging assembly supports night vision shooting of a camera as shown in FIG. 1;

FIG. 11 is a schematic diagram of an example of filter color wheel expansion in which the imaging assembly as shown in FIG. 1 supports spectrum acquisition of a camera;

12 is a schematic diagram of an example of a spectral curve supported by the extended instance as shown in FIG. 11;

FIG. 13 is a schematic diagram of another example of a spectral curve supported by the extended instance as shown in FIG. 11;

FIG. 14 is an exemplary flowchart of a filter control method for a camera in another embodiment;

FIG. 15 is a schematic flowchart of an example of the filter control method shown in FIG. 14 .

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model more clearly understood, the present utility model will be further described in detail below with reference to the accompanying drawings and examples.

FIG. 1 is a schematic diagram of the assembly structure of an imaging assembly in one embodiment. FIG. 2 is a schematic diagram of an exploded structure of the imaging assembly shown in FIG. 1 . FIG. 3 is a schematic diagram of a control architecture of the imaging component as shown in FIG. 1 applied in a camera. Referring to FIG. 1 in conjunction with FIG. 2 and FIG. 3 , in one embodiment, the imaging assembly of the camera may include a lens 20 , a sensing module 30 , a filter assembly 50 and a driving assembly 40 , and the lens 20 , the sensing module The group 30 , the filter assembly 50 and the driving assembly 40 can be assembled with each other through the lens mount 10 .

The lens mount 10 includes a base 11 , a support plate 12 and a mounting plate 13 , wherein the base 11 is provided with a view hole 100 , the support plate 12 is located at the side of the base 11 , and supports the mounting plate 13 on the side of the view hole 100 . above.

The lens 20 can use M12 mount, C mount, CS mount, The lens 20 can be fixedly installed on the lens holder 10 , specifically, the lens 20 can be fixedly installed on the mounting plate 13 , so that the field of view is aligned with the field of view hole 100 . Furthermore, as can be seen from FIG. 1 , the base 11 , the support plate 12 and the mounting plate 13 form an accommodating space, and the lens 20 can be partially arranged in the accommodating space. For convenience of description, the field of view hole 100 is equivalently described as the imaging field of view 100 hereinafter.

The sensing module 30 may include, for example, a CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) or a CCD (Charge Coupled Device, charge coupled device) or any other image sensor based on exposure imaging. Wherein, the sensing module 30 can be fixedly installed on the lens holder 10, specifically, the sensing module 30 can be installed on a PCB (Printed Circuit Board, printed circuit board) 300, and the sensing module 30 is installed The PCB 300 can be fixed to the base 11 of the lens mount 10 by means of fasteners such as screws or by bonding, and the image sensor of the sensing module 30 is exposed to the imaging field of view 100 . That is, the image sensor of the sensing module 30 is disposed within the imaging field of view 100 formed by the external light entering the camera through the lens 20 , and has a photosensitive surface located within the imaging field of view 100 of the lens 20 .

The filter assembly 50 has a rotation axis deviated from the imaging field of view 100 of the camera, and is rotatably arranged between the lens 20 and the sensing module 30, wherein the filter assembly 50 has a rotation axis deviated from the imaging field of view 100 of the camera. The outer rotation axis includes at least two filter elements 51 and 52 arranged around the rotation axis, and the filter properties of the at least two filter elements 51 and 52 are different from each other.

At least two filter elements 51 and 52 can alternately pass through the aforementioned accommodating space with the rotation of the filter assembly 50 . Thus, the at least two filter elements 51 and 52 can alternately form projections of the image sensor covering the sensing module 30 within the imaging field of view 100 . In addition, the sensing module may further include an electronic shutter. During the period from when the electronic shutter is opened to when the electronic shutter is closed, the projection formed by any one of the at least two filter elements 51 and 52 in the imaging field of view 100 always covers the sensor. The image sensor of the module 30 .

In the embodiments shown in FIGS. 1 to 3 , the filter assembly 50 includes two filter elements 51 and 52 as an example. In addition, in the embodiments shown in FIGS. 1 to 3 , the filter element 50 is only a circular plane shape, and the filter elements 51 and 52 are fan-shaped plane shapes and are combined with each other as an example, but this does not mean that Other forms of filter assembly 50 and filter elements 51 and 52 are excluded. Wherein, the circular plane filter assembly 50 may be referred to as a color filter wheel, and the fan-shaped plane filter elements 51 and 52 may be referred to as sector filters.

In addition, in the embodiments shown in FIGS. 1 to 3 , the central angles of the filter elements 51 and 52 are both 180 degrees as an example, but in practical applications, one of the filter elements 51 and 52 may be set The central angle of one is less than 180 degrees, and the central angle of the other is greater than 180 degrees. Moreover, for the case where the number of filter elements is more than two, the central angle of the filter elements can be set to a smaller equal value, for example, the central angles of the four filter elements are all 90°, or the The central angle may be set as a non-equal value, for example, the central angle of at least one of the four filter elements is larger/smaller than 90 degrees, and the remaining central angles are smaller/greater than 90 degrees.

The drive assembly 40 is connected to the filter assembly 50 in a driving manner. For example, the rotation axis of the drive assembly 40 and the rotation axis of the filter assembly 50 can be aligned, so as to provide a support with rotational freedom to the filter assembly 50, so that the filter element 51 and the filter assembly 50 are supported. 52 alternately blocks the imaging field of view 100 with the rotation of the filter assembly 50 . Specifically, the base 11 of the lens mount 10 has a motor mounting plate 14 on the other side opposite to the supporting plate 12 , the driving assembly 40 can be mounted on the motor mounting plate 14 by screwing, and the output shaft of the driving assembly 40 It is connected at the center of the filter assembly 50 , so that the filter assembly 50 is supported between the base 11 and the lens 20 mounted on the mounting plate.

Based on the above structure, the drive assembly 40 can drive the filter assembly 50 to rotate, and when the drive assembly 40 can drive the filter assembly 50 to rotate, the filter elements 51 and 52 of the filter assembly 50 can circulate through the imaging field of view 100, and , the sensing module 50 can expose and image the image when each filter element 51 or 52 forms an effective in-position state in which the imaging field of view 100 is completely blocked.

4a to 4d are schematic diagrams of exposure cycles of the imaging assembly shown in FIG. 1 .

4a, before the filter element 51 covers the sensing module 30, when the splicing boundary 500 between the filter elements 51 and 52 begins to block the sensing module 30, the filter element 51 In the effective in-position state where the imaging field of view 100 is fully covered, the sensing module 30 stops exposing until the splicing boundary 500 between the filter elements 51 and 52 crosses the sensing module 30, that is, the sensing module 30 stops exposing The shortest duration of is at least the rotation duration of the combined boundary 500 passing through the invalid exposure interval α_inv.

Referring to FIG. 4b again, following the state shown in FIG. 4a , after the splicing boundary 500 between the filter elements 51 and 52 crosses the sensing module 30 , the sensing module 30 can be completely closed by the filter element 51 . Expose imaging under the condition of occlusion, until the splicing limit 500 between the filter elements 51 and 52 starts to occlude the sensing module 30 again, that is, the exposure time of the sensing module 30 can be as long as the splicing limit 500 after the effective exposure interval. The rotation duration of α_samp.

Please continue to refer to FIG. 4c , before the filter element 52 covers the sensing module 30, when the splicing boundary 500 between the filter elements 51 and 52 begins to block the sensing module 30, the filter element 52 is not in a position sufficient to satisfy the In the effective in-position state where the imaging field of view 100 is fully covered, the sensing module 30 stops exposing again until the splicing boundary 500 between the filter elements 51 and 52 crosses the sensing module 30, that is, the sensing module 30 stops. The shortest duration of exposure is still at least the rotation duration of the stitching boundary 500 passing through the invalid exposure interval α_inv.

Please refer to FIG. 4d finally, following the state shown in FIG. 4c, after the splicing boundary 500 between the filter elements 51 and 52 crosses the sensing module 30, the sensing module 30 can be completely in the filter element 52. In the case of occlusion, the imaging is exposed until the splicing boundary 500 between the filter elements 51 and 52 begins to occlude the sensing module 30 again, that is, the exposure time of the sensing module 30 can still be as long as the splicing boundary 500 after effective exposure. The rotation duration of the interval α_samp.

It can be seen from FIG. 4a to FIG. 4d that the effective in-position state of each filter element 51 or 52 (the splicing boundary 500 is within the effective exposure interval α_samp) triggers the exposure duration, which does not exceed the effective in-position state of the filter element 51 or 52. The duration of the bit state (ie, total occlusion of the imaging field of view 100 ). When the combined boundary 500 between the filter elements 51 and 52 is located in the imaging field of view 100, the filter elements 51 and 52 both form complementary partial occlusions for the imaging field of view 100. At this time, the filter elements 51 and 52 are It is not a valid in-position state.

Referring back to FIG. 3 , a camera applying the above imaging assembly may include a processor 90 , the processor 90 is configured to control the drive assembly 40 to drive the filter assembly 50 to rotate, so that each filter element 51 and 52 of the filter assembly 50 circulates through The imaging field of view 100; and the processor 90 is further configured to trigger the exposure imaging of the sensing module 30 in response to each filter element 51 or 52 forming an effective in-position state that the imaging field of view 100 is completely blocked.

In order to ensure that the exposure imaging of the sensing module 30 is synchronized with the effective in-position state of each filter element 51 or 52 (for example, when the exposure frequency is at a fixed value), the processor 90 can adjust the rotational speed of the driving assembly 40 to make the transmission The exposure duration of the sensing module 30 falls within the effective in-position duration range of each filter element 51 or 52 synchronously.

Considering the accuracy of adjusting the rotational speed of the drive assembly 40 , the rotational speed may be adjusted in real time by means of closed-loop control, or the rotational speed may be corrected periodically by means of closed-loop feedback.

Still referring to FIGS. 1 to 3 , in this embodiment, the imaging assembly of the camera may further include a photodetector 60 , and the photodetector 60 may be arranged at a fixed position adjacent to the imaging field of view 100 . It can be seen from FIG. 1 to FIG. 3 that the base 11 of the lens mount 10 has a detector mounting plate 15 at a position close to the support plate 12, the photodetector 60 can be arranged on the detector bracket 600, and the detector The bracket 600 is fixed to the detector mounting plate 15 by screwing.

In addition, the light-sensing detector 60 is used to detect the light-sensing change produced by the filter assembly 50 at the splicing boundary 500 between the filter elements 51 and 52 .

For example, the photodetector 60 may have a light transmitter 61 and a light receiver 62 arranged on opposite sides of the filter assembly 50, respectively, and the filter assembly 50 may rotate within a slot between the light transmitter 61 and the light receiver 62 , wherein the filter elements 51 and 52 alternately transmit and cut off the light of the optical transmitter 61, so that the optical receiver 62 generates a high/low voltage transition signal in response to successful and unsuccessful reception of the light of the optical transmitter 61, It is used to determine that the image sensor of the sensing module 30 is or is about to receive the light transmitted by the filter element 51 or 52 .

That is, when the test light emitted by the optical transmitter 61 changes due to different light transmission properties of the filter element 51 or 52, the sensing result of the optical receiver 62 will also undergo corresponding changes in light perception. In addition, the light sensing detector 60 may output a detection pulse signal to the processor 90 in response to the detected light sensing change, wherein the detection pulse signal may have a response to the light sensing change and a difference between the filter elements 51 and 52 The flattened boundary 500 is the waveform of the transition node.

The processor 90 can monitor the effective presence of each filter element 51 and 52 by detecting the photosensitive change frequency generated by the filter element splicing boundary 500 between the filter elements 51 and 52 sensed by the photosensitive detector 60. The switching frequency of the state, and according to the synchronization deviation between the switching frequency of the effective in-position state and the exposure frequency of the sensing module 30, the rotational speed of the driving assembly 40 is adjusted so that the exposure time of the sensing module 30 synchronously falls within each The effective in-bit duration of each filter element 51 or 52 is within the range. That is, the driving component 40 can use the frequency of the light-sensing change sensed by the light-sensing detector as a closed-loop feedback.

For example, if the driving assembly 40 includes a DC motor (eg, a brushless DC motor), the rotational speed of the DC motor can be controlled by the frequency of the light-sensing change sensed by the light-sensing detector 60 . Specifically, the processor 90 can determine the switching frequency of the effective in-position state of each filter element 51 and 52 according to the switching identification frequency of the effective in-position state, and according to the difference between the determined switching frequency and the exposure frequency of the sensing module 30 The speed of the drive assembly 40 is adjusted in real time according to the synchronization deviation between the two.

For another example, if the driving component 40 includes a stepping motor, the rotational speed of the stepping motor can be calibrated based on the light sensing change frequency sensed by the light sensing detector 60 . Specifically, the processor 90 can estimate the switching frequency of the effective presence state of each filter element 51 and 52 by counting the step size of the stepping drive assembly, and, according to the switching identification frequency of the effective presence state, periodically The estimated switching frequency is corrected and the rotation angle of the stepping motor is compensated, so as to indirectly realize the constraint adjustment of the rotational speed through the compensation of the rotation angle.

In addition, the processor 90 detects the light perception change generated by the filter element splicing boundary 500 between the filter elements 51 and 52 sensed by the light sensor detector 60, and can also estimate the light perception change whenever the light perception change is detected. The filter element 51 or 52 that is about to reach the imaging field of view 100 starts to fully cover the delay time of the effective in-position interval, and when the estimated delay time arrives, the sensing module 30 is activated to start exposure according to the preset exposure time. That is, the exposure frequency of the sensing module 30 can be synchronized with the photosensitive change frequency of the filter element detected by the photodetector 60 generated by the splicing boundary 500 between the filter elements 51 and 52 .

FIG. 5 is a schematic diagram of an example of a filter color wheel in which the imaging assembly as shown in FIG. 1 supports night vision shooting of a camera. Referring to FIG. 5 , the filter assembly 50 ′ in this example includes alternately arranged first filter elements 51 ′ and second filter elements 52 ′, wherein the first filter element 51 ′ is sensitive to infrared light (wavelength at 700 to 1000 nm), the second filter element 52' transmits infrared light. Further, the first filter element 51' that cuts off infrared light can transmit visible light, and the second filter element 52' that transmits infrared light can cut off visible light, or can transmit visible light at the same time (ie, full projection).

At this time, the photodetector 60' can be selected as a photo-interrupting sensor, wherein the photodetector 60' has an infrared emitting end and an infrared receiving end respectively arranged on opposite sides of the filter assembly 50', and the infrared emitting end and the infrared The arrangement position of the receiving end may refer to the arrangement positions of the optical transmitter 61 and the optical receiver 62 as shown in FIG. 3 . The second filter element 52 can transmit the light of the infrared emission end, and the first filter element 51 can cut off the light of the infrared emission end.

Moreover, FIG. 5 shows the effective in-position interval α_cov that completely blocks the imaging field of view 100 , and there is a pre-check deviation interval α_pre between the fixed position of the photodetector 60 ′ and the effective in-position interval α_cov, that is, when the first When the splicing boundary 500' of the filter element 51' and the second filter element 52' reaches the fixed position of the photo-interrupting sensor 60', the first filter element 51' or the second filter element 52' has not yet reached the effective in-position interval α_cov.

At this time, the processor 90 can estimate that the combined boundary 500 ′ of the first filter element 51 ′ and the second filter element 52 ′ exceeds the effective in-position interval α_cov and makes the first filter element 51 ′ that is about to reach the imaging field of view 100 Or the second filter element 52' starts to fully cover the delay duration of the effective in-position interval α_cov, the processor 90 may also activate the sensing module 30 to start exposure according to the preset exposure duration after the predicted delay duration arrives.

After the sensing module 30 starts to expose, its exposure duration can be the maximum duration of the effective exposure interval α_samp that continuously covers the imaging field of view 100 , and within the invalid exposure interval α_inv that is not sufficient to fully cover the imaging field of view 100 , the sensing The exposure of the module 30 is stopped.

Among them, the phase amplitude of the invalid exposure interval α_inv is not less than the phase amplitude of the valid in-position interval α_cov, and although the phase amplitude of the invalid exposure interval α_inv is smaller than the phase amplitude of the pre-check deviation interval α_pre in FIG. 5 as an example, this does not mean It should be understood that there is a necessary value relationship between the phase amplitude of the invalid exposure interval α_inv and the phase amplitude of the precheck deviation α_pre, that is, the phase amplitude of the invalid exposure interval α_inv may also be equal to or greater than the phase amplitude of the precheck deviation interval α_pre.

It can be understood that no matter what value relationship exists between the invalid exposure interval α_inv and the phase amplitude of the pre-check deviation α_pre, the frame interval between two consecutive valid exposure intervals α_samp can be determined by the invalid exposure interval α_inv.

FIG. 6 is a schematic diagram of signal timing in the example shown in FIG. 5 . See Figure 6:

When the first filter element 51' passes through the notch between the infrared emitting end and the infrared receiving end of the photodetector 60', due to the cut-off characteristic of the first filter element 51' to infrared light, the infrared receiving end will The infrared light emitted by the infrared transmitter cannot be detected and a low level is generated;

When the second filter element 52' passes through the notch between the infrared emitting end and the infrared receiving end of the photodetector 60', due to the light transmittance of the second filter element 52' to infrared light, the infrared receiving end will A high level is generated due to the detection of the infrared light emitted by the infrared transmitter;

In this way, a pulsed square wave can be formed which responds to changes in light perception and takes the combined boundary 500' between the first filter element 51' and the second filter element 52' as a transition node.

Accordingly, the processor 90 can monitor the effectiveness of the first filter element 51' and the second filter element 52' in response to the rising and falling edges in the output signal of the photodetector 60' as shown in FIG. 6 . The switching frequency of the in-position state, and according to the synchronization deviation between the switching frequency of the effective in-position state and the exposure frequency of the sensing module 30, the rotational speed of the driving assembly 40 is adjusted so that the exposure time of the sensing module 30 is The exposure duration synchronously falls within the effective in-position duration range of the first filter element 51 ′ or the second filter element 52 ′ corresponding to the effective exposure interval α_samp.

Therefore, the exposure output of the imaging module shown in FIG. 6 includes an imaging image P1 generated by exposure imaging when the first filter element 51' is effectively in place, and the second filter element 52' is effectively in place The imaged image P2 produced by exposure imaging. That is, the filter assembly 50 is disposed between the lens 20 and the sensing module 30, so that the image sensor of the sensing module 30 can alternately generate the first image P1, and the second image P2 when the imaging field of view 100 is blocked by the second filter element 52 .

And, in the exposure output of the imaging module shown in FIG. 6 , the generation of the imaging image P1 and the imaging image P2 is constrained within the effective exposure interval α_samp, and the inter-frame interval between the imaging image P1 and the imaging image P2 is given by The invalid exposure interval α_inv is determined.

Based on the above principles, the processor 90 can also image the sensing module 30 when the first filter element 51 ′ and the second filter element 52 ′ are effectively in place during each rotation period of the filter assembly 50 ′. The obtained images P1 and P2 are subjected to image fusion processing to obtain a fusion image, so as to realize the night shooting function.

Moreover, the processor 90 can be further configured to control the start and stop of the driving assembly 40 according to the day and night time of the time zone where the camera is located, wherein the processor 90 can control the driving assembly 40 to stop at the second filter element 52' in the daytime period. The phase position is effectively in place, and the processor 90 can control the drive assembly 40 to start up during the night time period.

It can be understood that, FIG. 5 only takes one first filter element 51' and one filter element 52' as an example, but the filter assembly 50 may also include multiple first filter elements 51' and multiple filter elements 52'. Optical element 52'. For example, the number of the first filter elements 51' or the second filter elements 52' is an even number such as 2, 4, 6 or 8. For another example, the number of the first filter elements 51 and the number of the second filter elements 52 may be the same, and the first filter elements 51' and the second filter elements 52' are alternately arranged.

Although the example shown in FIG. 5 shows an equiangular distribution in which the first filter element 51 ′ and the second filter element 52 ′ both cover a 180-degree phase interval, in practical applications, the first filter element 51 ' and the second filter element 52' may not be arranged in an equiangular distribution.

FIG. 7 is a schematic diagram of an example of a color filter disk in which the imaging assembly as shown in FIG. 1 supports spectrum acquisition by a camera. Referring to FIG. 7 , the filter elements 51 ″ and 52 ″ of the filter assembly 50 ″ in this example cut off infrared light and transmit visible light in different wavelength ranges.

At this time, the photodetector 60'' can still choose a photo-interrupting sensor, but different from the example shown in FIG. 5, the photodetector 60'' in this example has two opposite sides respectively arranged on the filter assembly 50''. (The arrangement positions of the infrared transmitter and the infrared receiver can refer to the arrangement positions of the optical transmitter 61 and the optical receiver 62 as shown in FIG. 3 ).

Since the infrared light emitted by the infrared emitting end of the photodetector 60" is cut off for all the filter elements 51" and 52", in order to generate the photosensitive change at the combined boundary of the filter elements 51" and 52" , a splicing boundary can be formed between the adjacent filter elements 51 ″ and 52 ″ by fitting the fully transparent strips 600 , which are transparent to all wavelengths of infrared light and visible light.

In addition, FIG. 7 also shows the effective in-position interval α_cov that completely blocks the imaging field of view 100, and there is a pre-check deviation interval α_pre between the fixed position of the photodetector 60″ and the effective in-position interval α_cov. Moreover, the processor 90 can estimate that the split boundary formed by the fully transparent strip 600 between the filter elements 51" and 52" crosses the effective in-position interval α_cov and is sufficient for the filter element 51" or 52" to fully cover the effective in-position interval α_cov. Correspondingly, the processor 90 can activate the sensing module 30 to start exposure after the predicted delay time is reached.

After the sensing module 30 starts to expose, its exposure duration can be the maximum duration of the effective exposure interval α_samp that continuously covers the imaging field of view 100 , and within the invalid exposure interval α_inv that is not sufficient to fully cover the imaging field of view 100 , the sensing The exposure of the module 30 is stopped.

FIG. 8 is a schematic diagram of signal timing in the example shown in FIG. 7 . See Figure 8:

When the infrared receiving end of the photodetector 60" is blocked by the filter element 51" or 52" in the imaging field of view 100 and cannot sense the infrared light generated by the infrared transmitting end, a low level can be generated, and when the photodetector detects When the infrared receiving end of the visible light receiver of the visible light receiver 60" senses the infrared visible light generated by the infrared transmitting end of the visible light transmitter, it can generate a high level;

Therefore, whenever the split boundary formed by the fully transparent strip 600 between the filter elements 51" and 52" passes through the notch between the infrared transmitting end and the infrared receiving end of the photodetector 60", the fully transparent strip 500 will Causes the infrared receiving end to produce short-term effective sensing of the infrared light at the infrared transmitting end, and generates a high-level narrow pulse width jump during effective sensing;

In this way, a pulsed square wave can be formed that responds to changes in light perception and uses the fully transparent bar 500 as a transition node.

Accordingly, the processor 90 can monitor the switching frequency of the active in-position states of the filter elements 51 ″ and 52 ″ in response to the high level narrow pulse width in the output signal of the photodetector 60 ″ as shown in FIG. 8 , and according to the synchronization deviation between the switching frequency of the effective in-position state and the exposure frequency of the sensing module 30 , the rotational speed of the driving assembly 40 is adjusted so that the exposure duration within the exposure duration of the sensing module 30 synchronously falls within the The filter element 51" or 52" corresponds to the effective in-bit duration range of the effective exposure interval α_samp.

Thus, the exposure output of the imaging module shown in FIG. 8 includes the imaging images P1 and P2 generated by exposure imaging when the filter elements 51 ″ and 52 ″ are respectively effectively in place. Also, in the exposure output of the imaging module shown in FIG. 8 , the generation of the imaging images P1 and P2 is constrained within the effective exposure interval α_samp, and the inter-frame interval between the imaging image P1 and the imaging image P2 is determined by the invalid exposure The interval α_inv is determined.

Based on the above-mentioned principle, the processor 90 can also, during each rotation period of the filter assembly 50", perform the image processing on the images P1 and P2 obtained by the imaging of the sensing module 30 when the filter elements 51" and 52" are effectively in place, respectively. Group spectral analysis to realize the function of a spectral camera.

It can be understood that, although the example shown in FIG. 7 takes the equiangular distribution manner in which the filter elements 51" and 52" both cover the 180-degree phase interval as an example, the filter elements 51" and 52" may not be set as Equiangular distribution.

In practical application, the fixed position of the photodetector 60' or 60" can be arbitrarily adjusted according to the needs of the spatial arrangement, and the processor 90 can adjust the estimated time for the change of the phase amplitude of the pre-detection deviation interval α_pre caused by this. to fit.

Furthermore, since the phase amplitude of the invalid exposure interval α_inv and the valid exposure interval α_samp may be complementary, the ratio of the invalid exposure interval α_inv to the valid exposure interval α_samp can be adjusted arbitrarily according to the desired exposure duration.

Alternatively, for the adaptation of the exposure duration, the drive assembly 40 can also be controlled to rotate at a variable speed, that is, to rotate at a rotational speed different from (eg higher than) the effective exposure interval α_samp in the invalid exposure interval α_inv.

Moreover, whether it is the example shown in FIG. 5 or the example shown in FIG. 7 , the rotation speed of the filter assembly 50' or 50" and the exposure time of the sensing module 30 can be set according to the desired frame rate.

For example, for the example shown in FIG. 5 , assuming that the desired frame rate of the fusion image is f frames/second, the sensing module 30 needs to utilize the effective effects of the first filter element 51 ′ and the second filter element 52 ′. Exposure imaging in the in-position state is 2f frames/sec. To this end, the rotational speed of the driving assembly 40 can be set to f revolutions/sec. In addition, the sensing module 30 is connected between the first filter element 51' and the second filter element 52'. When each of them is valid, the exposure duration that completely covers the valid exposure interval α_samp can be set to Xms, and the inter-frame interval of the invalid exposure interval α_inv occupies Yms, where 2×(X+Y)=1/f.

The above example is the same for the example shown in FIG. 7 .

If it is desired to increase the desired frame rate, the rotational speed of the driving assembly 40 may be increased proportionally, or the number of filter elements may also be increased.

As the number of filter elements increases, the size design of the filter assembly 50 and the positional arrangement relative to the sensing module 30 need to be considered.

FIG. 9 is a schematic diagram of the layout principle of the color filter disk of the imaging assembly shown in FIG. 1 . Referring to FIG. 9 , the effective in-position interval α_cov that completely blocks the imaging field of view 100 can be determined by the width dimension W of the sensing module 30 in the tangential direction of the filter assembly 50 and the relative relationship of the sensing module 30 to the filter The center-to-center distance E of the component 50 is determined. That is, the smaller the width dimension W of the sensing module 30 and/or the larger the distance E from the center of the sensing module 30, the narrower the interval range of the effective presence interval α_cov; the narrower the interval range of the effective presence interval α_cov , the number of filter elements can be more. At the same time, the radius of the filter assembly 50 needs to be greater than the sum of the center distance D of the sensing module 30 and the length L of the sensing module 30 in the radial direction of the filter assembly 50 .

It can be understood from this that the above-mentioned embodiments should not limit the number of the filter elements unnecessarily. That is, the number of filter elements included in the filter assembly may be at least two.

FIG. 10 is a schematic diagram of an example of the expansion of the filter color wheel in which the imaging assembly as shown in FIG. 1 supports night vision shooting of the camera. Referring to FIG. 10 , in this extended example, the filter assembly 70 may include two pairs of alternately arranged first filter elements 71 and second filter elements 72 , wherein the first filter element 71 cuts off infrared light, and Visible light see-through, the second filter element 72 is transparent to both infrared light and visible light, and the photodetector 60' can select a photo-interrupting sensor that utilizes infrared light testing to detect the filter element 70 between the filter elements 71 and 72. The light perception change produced by the flattened boundary 700 between.

Compared with the example shown in FIG. 5 , the extended example shown in FIG. 8 can support twice the expected frame rate of the example shown in FIG. That is, in the example shown in FIG. 8 , 4×(X+Y)=1/f, but the exposure time of the sensing module 30 will be shorter than the example shown in FIG. 5 .

In addition, in the extended example shown in FIG. 8 , the two pairs of the first filter element 71 and the second filter element 72 can be arranged equiangularly or unequally, as long as they can match the exposure time of the sensing module 30 can match.

FIG. 11 is a schematic diagram of an example of the expansion of the filter color wheel in which the imaging assembly as shown in FIG. 1 supports the spectrum acquisition of the camera. Referring to FIG. 11 , in this extended example, the filter element 70 ′ may have four filter elements 71 ′, 72 ′, 73 ′ and 74 ′ that cut off infrared light and transmit visible light in different wavelength ranges. . Moreover, every two adjacent filter elements of the four filter elements 71', 72', 73' and 74' can form a split boundary by fitting the fully transparent strip 800, so that the light-sensing detector 60" can detect the filter. The light perception changes produced by the assembly 70 ′ between the filter elements formed by the split boundaries formed by the translucent strips 800 are provided to the processor 90 .

For example, the four filter elements 71', 72', 73' and 74' can be selected in any combination from the following alternative filters:

Alternative filter 1: Band-transmitting the three wavelength ranges of blue visible light Band_B1 from 430 to 460 nm, green visible light Band_G1 from 540 to 560 nm, and red visible light Band_R1 from 640 to 660 nm;

Alternative filter 2: Band-transmitting the three wavelength ranges of blue visible light Band_B2 from 450 to 470 nm, green visible light Band_G2 from 520 to 540 nm, and red visible light Band_R2 from 620 to 640 nm;

Optional filter 3: Band-transmitting the two wavelength ranges of blue visible light Band_B3 from 490 to 510 nm and red visible light Band_R3 from 570 to 590 nm;

Optional filter 4: Band-transmitting the two wavelength ranges of blue visible light Band_B4 from 400 to 420 nm and red visible light Band_R4 from 670 to 690 nm;

Alternative filter 5: Band-transmit to the two wavelength ranges of blue visible light Band_B5 from 470 to 490 nm and red visible light Band_R5 from 590 to 610 nm.

FIG. 12 is a schematic diagram of an example of a spectral curve supported by the extended instance shown in FIG. 11 . As shown in FIG. 12 , using the filter assembly 70 ′ including the above-mentioned four filter elements 71 ′, 72 ′, 73 ′ and 74 ′, spectrum acquisition in multiple visible light wavelength ranges can be provided, so that the spectral analysis can be used to simulate Combine the spectral curves of the visible light band from 400 to 690 nm.

Moreover, the alternative filters can also be used in combination of two, three or five, so as to support the above-mentioned four filter elements 71', 72', 73' and 74' to be replaced by other filter elements. instance.

FIG. 13 is a schematic diagram of another example of a spectral curve supported by the extended instance shown in FIG. 11 . As shown in FIG. 13 , in addition to the optional filter that transmits visible light, a filter element that transmits infrared light can be further added to the filter assembly 70 , so that the spectral curve can be related to the visible light band at the same time. And infrared band Band_Inf, such as 710 to 730nm, 750 to 770nm, 810 to 830nm and 850 to 870nm and other bands.

That is, the filter elements included in the filter assembly 70 can be further expanded to six, seven or even more.

Moreover, the filter elements included in the filter assembly 70 may be arranged equiangularly or unequally, as long as it can match the exposure time of the sensing module 30 .

FIG. 14 is an exemplary flowchart of a filter control method for a camera in another embodiment. Referring to FIG. 14, in another embodiment, a filter control method for a camera may include:

S1410: Controlling the drive assembly to drive the filter assembly between the lens and the sensing module to rotate, so that at least two filter elements of the filter assembly circulate through the imaging field of view of the lens;

S1420: Trigger exposure imaging of the sensing module in response to the effective presence state in which each filter element completely blocks the imaging field of view, wherein the exposure duration triggered by the effective presence state of each filter element does not exceed the The duration for which the filter element forms a total occlusion of the imaging field of view.

The above-mentioned S1410 may further use the frequency of the light-sensing change sensed by the light-sensing detector as the closed-loop feedback of the driving component. For example, the S1410 can detect the light sensitivity change sensed by the light sensor detector, and monitor the switching frequency of the effective in-position state of each filter element according to the frequency of the light-sensing change, and monitor the switching frequency of the effective in-position state according to the switching frequency of the effective in-position state. The synchronization deviation between the exposure frequencies of the modules adjusts the rotational speed of the drive assembly, so that the exposure duration of the sensing module synchronously falls within the effective in-position duration range of each filter element.

The above-mentioned S1420 can further synchronize the exposure frequency of the sensing module with the frequency of the light sensitivity change sensed by the photosensitive detector. For example, S1420 can detect the light perception change sensed by the light perception detector, and, whenever the light perception change is detected, estimate the delay time that the filter element that is about to reach the imaging field of view begins to fully cover the effective in-position interval. When the estimated delay time arrives, the sensor module is activated to start exposure according to the preset exposure time.

FIG. 15 is a schematic flowchart of an example of the filter control method shown in FIG. 14 . Referring to Figure 15, the filter control method shown in Figure 14 can be extended to include the following steps:

S1510: Control the driving component to drive the filter component between the lens and the sensing module to rotate at a preset default rotational speed, so that at least two filter elements of the filter component circulate through the imaging field of the lens.

S1520: Detect the switching of the valid in-position state of the filter element.

S1530: In response to the detected effective in-position state switching, trigger the sensing module to expose the image with a preset exposure duration, and then return to S1520.

S1540: Monitor the synchronization deviation between the switching frequency of the effective in-position state of the filter element and the exposure frequency of the sensing module.

S1550: In response to the monitored synchronization deviation, adjust the output rotational speed of the drive assembly, and then return to S1540.

The rotational speed adjustment described in this step may be real-time adjustment in the case of using a DC motor as the driving component, and may be periodically corrected in the case of using a stepping motor as the driving component.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall include within the scope of protection of the present invention.

Claims (16)

1. A filter device for a camera, comprising:

a filter assembly having an axis of rotation offset from an imaging field of view of the camera and including a first filter element and a second filter element disposed about the axis of rotation, wherein the first filter element is cut off from infrared light and the second filter element transmits infrared light;

and the driving component is in transmission connection with the filtering component, so that the first filtering element and the second filtering element alternately block the imaging field of view along with the rotation of the filtering component.

2. The filter device of claim 1, wherein the first filter element cuts off infrared light and transmits visible light, and the second filter element transmits infrared light and cuts off visible light, or transmits infrared light and transmits visible light.

3. The filter device of claim 2, wherein the filter assembly is circular-planar and the first filter element and the second filter element are sector-planar.

4. A filter device according to claim 3, wherein the first filter element and the second filter element each have a central angle of 180 degrees.

5. The light filtering device of claim 3, wherein one of said first light filtering element and said second light filtering element has a central angle of less than 180 degrees and the other of said first light filtering element and said second light filtering element has a central angle of more than 180 degrees.

6. The filtering device of claim 3, wherein said filtering assembly includes a plurality of first filtering elements and a plurality of second filtering elements, wherein the number of said first filtering elements and the number of said second filtering elements are the same, and the first filtering elements and the second filtering elements are alternately arranged.

7. The filtering device of claim 6, wherein the number of said first filtering elements or said second filtering elements is an even number.

8. A filter device according to claim 6, in which the number of said first filter elements or said second filter elements is 2, 4 or 8.

9. The filtering device of claim 6, wherein the first filtering element has a central angle of less than 90 degrees and the second filtering element has a central angle of less than 90 degrees.

10. The filter device of claim 1, wherein the drive assembly comprises a stepper motor or a dc motor.

11. A camera, comprising:

a lens mount;

the lens is fixedly arranged on the lens seat;

the sensing module is fixedly arranged on the lens mount and comprises an image sensor, wherein the image sensor is arranged in an imaging view field formed by the fact that external light rays are emitted into the camera through the lens;

the light filtering device of any one of claims 1 to 10, wherein the light filtering component of the light filtering device is disposed between the lens and the sensing module such that the image sensor alternately generates a first image when the imaging field of view is blocked by the first light filtering element and a second image when the imaging field of view is blocked by the second light filtering element.

12. The camera of claim 11, wherein the drive assembly is fixedly attached to the lens mount by a fastener, wherein an axis of rotation of the drive assembly is aligned with an axis of rotation of the filter assembly.

13. The camera of claim 12, wherein the first filter element and the second filter element alternate to form projections covering the image sensor within the imaging field of view.

14. The camera of claim 13, wherein the lens mount comprises a base, a support plate, and a mounting plate, wherein the base, the support plate, and the mounting plate form an accommodation space, the lens portion is disposed in the accommodation space, and the first filter element and the second filter element alternate through the accommodation space as the filter assembly rotates.

15. The camera of claim 11, wherein the sensing module further comprises an electronic shutter, and a projection of the first filter element or the second filter element formed in the imaging field of view covers the image sensor at all times during a period from when the electronic shutter is opened to when the electronic shutter is closed.

16. The camera of claim 11, wherein the camera further comprises: a light-interruption sensor including a light receiver and a light transmitter;

the filter assembly is rotatably disposed between the optical receiver and the optical transmitter, wherein one of the first filter element and the second filter element transmits light of the optical transmitter, and the other of the first filter element and the second filter element cuts off light of the optical transmitter;

when the filter assembly rotates, the optical receiver responds to the successful and failed reception of the light of the optical transmitter to generate a voltage jump signal for determining whether the image sensor is receiving the light transmitted by the first filter element or the light transmitted by the second filter element.

Images