Aperture diaphragm and camera module including the same
阅读说明:本技术 孔径光阑和包括孔径光阑的相机模块 (Aperture diaphragm and camera module including the same ) 是由 金在京 尹永復 于 2019-08-19 设计创作,主要内容包括:本申请涉及孔径光阑和包括孔径光阑的相机模块。孔径光阑包括:壳体;叶片,设置在壳体中并且旋转以形成具有可变尺寸的入射孔;以及可旋转地移动叶片的驱动器。每个叶片包括通孔和设置在通孔的形成入射孔的内表面上的突起。(The present application relates to an aperture stop and a camera module including the aperture stop. The aperture stop includes: a housing; a blade disposed in the housing and rotating to form an entry hole having a variable size; and a driver rotatably moving the blade. Each blade includes a through hole and a protrusion disposed on an inner surface of the through hole forming the entry hole.)
1. An aperture stop, comprising:
a housing;
a blade disposed in the housing and configured to rotate to form an entry hole having a variable size; and
a driver configured to rotatably move the blade,
wherein each blade includes a through hole and a protrusion provided on an inner surface of the through hole, which forms the entry hole.
2. The aperture stop according to claim 1, wherein each blade includes a blocking portion on a top surface or a bottom surface in the optical axis direction.
3. The aperture stop according to claim 1, wherein the protrusion is formed by an etching process of the blade.
4. The aperture stop of claim 2, wherein each barrier comprises at least one of a carbon-based material, a chromium-based oxide, a copper-based oxide, a manganese-based oxide, a cobalt-based oxide, a sulfide, and a nickel-based oxide.
5. The aperture stop of claim 1, further comprising a blocking spacer disposed on an image side of the housing.
6. The aperture stop of claim 1, wherein the driver comprises:
a drive ring configured to rotate such that the blades rotate about rotational axes of the blades, respectively; and
a magnet and a coil disposed on at least a portion of the drive ring in a circumferential direction.
7. The aperture stop of claim 6, wherein the magnet is fixedly disposed with the drive ring, and
the coil is disposed in the housing to face the magnet.
8. The aperture stop of claim 6, wherein the coil is fixedly disposed with the drive ring, and
the magnet is disposed in the housing to face the coil.
9. The aperture stop of claim 6, wherein the drive ring includes a stop configured to limit rotation of the blades.
10. The aperture stop according to claim 7, wherein the housing includes an annular yoke in a portion of the housing corresponding to the magnet in the optical axis direction, and
the yoke includes an enlarged diameter portion in a circumferential direction to vary a thickness in a radial direction.
11. The aperture stop according to claim 1, wherein the blades are driven in a multistage manner, wherein the blades are rotatably moved to form N entry holes having different sizes by mutual combination of the blades, wherein N is a positive integer.
12. The aperture stop of claim 7, wherein the magnet is fixed to the drive ring by insert injection.
13. The aperture stop of claim 7, further comprising position sensors disposed on both sides of the coil.
14. The aperture stop of claim 6, further comprising a ball bearing disposed between the drive ring and a surface of the housing.
15. The aperture stop of claim 1, wherein the blade is configured to close the entry hole when rotated innermost.
16. The aperture stop of claim 6, wherein the drive ring includes a drive shaft configured to be inserted into a drive shaft hole of the blade to rotate the blade.
17. The aperture stop of claim 16, wherein the drive shaft aperture is inclined with respect to a direction of rotation of the drive ring, and a size of the entry hole varies based on a position of the drive shaft within the drive shaft aperture.
18. A camera module, comprising:
a lens barrel accommodating lenses stacked in order in an optical axis direction; and
the aperture stop of claim 1, disposed between and aligned with the lenses.
Technical Field
The following description relates to an aperture stop and a camera module including the aperture stop.
Background
In general, products that cause degradation of camera images due to temperature changes or the surrounding environment are mainly monitoring cameras and the like in closed-circuit television (CCVD) systems. With the increase in demand for and application to automotive cameras, a solution to image degradation caused by the surrounding environment is required.
For example, the most advanced automobiles are equipped with a rear view camera and various other cameras, such as a view-around monitoring (SVM) camera or the like, mounted on the entire body, including a rear view mirror and front and rear bodies, for an Advanced Driver Assistance System (ADAS). In the future, it is expected that many cameras having various functions will be mounted on automobiles.
Furthermore, as the demand and demand for autonomous driving increases, the importance of obtaining stable images by an automobile ADAS camera is increasing.
Light Emitting Diodes (LEDs) are used in traffic signs, traffic lights and various types of lighting. Since most LEDs for illumination and signals use a Pulse Width Modulation (PWM) control method, they may individually have a blinking period according to respective LED illumination. Therefore, LED flicker may occur in an image input to the camera. The method of preventing LED flicker is called LED Flicker Mitigation (LFM).
The flash period of the LED illumination depends on the plurality of light sources, and the exposure time of the camera should be applied over the flash period of the LEDs to achieve LFM. Due to these characteristics, some or all of the images may be saturated in a daytime environment under clear weather, and the dynamic range of these saturated images may be reduced.
In order to perform LFM with a relatively small diameter of the aperture stop, the exposure time of the camera is longer than the blinking period of the LEDs to have at least one LED "on" period. Meanwhile, in the case where the aperture stop has a relatively large diameter, it is difficult to implement LFM when the exposure time is reduced to prevent image saturation to compensate for the dynamic range.
Therefore, there is a need for a camera having means for appropriately adjusting the exposure time and the amount of exposure.
Disclosure of Invention
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In one general aspect, an aperture stop includes: a housing; a blade disposed in the housing and rotating to form an entry hole having a variable size; and a driver rotatably moving the blade. Each blade includes a through hole and a protrusion provided on an inner surface of the through hole, which forms the entry hole.
Each of the blades may include a blocking portion on a top surface or a bottom surface in the optical axis direction.
The protrusion may be formed by an etching process of the blade.
Each barrier may include at least one of a carbon-based material, a chromium-based oxide, a copper-based oxide, a manganese-based oxide, a cobalt-based oxide, a sulfide, and a nickel-based oxide.
The aperture stop may include a blocking spacer disposed on an image side of the housing.
The driver may include: a drive ring that rotates such that the blades rotate about rotation axes of the blades, respectively; and a magnet and a coil provided on at least a part of the drive ring in a circumferential direction.
The magnet may be fixedly provided with the drive ring, and the coil may be provided in the housing so as to face the magnet.
The coil may be fixedly provided with the drive ring, and the magnet may be provided in the housing so as to face the coil.
The drive ring may include a stop configured to limit rotation of the blades.
The housing may include an annular yoke in a portion of the housing corresponding to the magnet in the optical axis direction, and the yoke may include an enlarged diameter portion in a circumferential direction to vary in thickness in a radial direction.
The blades may be driven in a multi-stage manner, in which the blades are rotatably moved to form N entry holes having different sizes by the mutual combination of the blades, where N is a positive integer.
The magnet may be fixed to the drive ring by insert injection.
The aperture stop may include position sensors disposed on both sides of the coil.
The aperture stop may include a ball bearing disposed between the drive ring and a surface of the housing.
The blades may close the entry hole when rotated innermost.
The drive ring may include a drive shaft inserted into the drive shaft hole of the blade to rotate the blade.
The drive shaft hole may be inclined with respect to a rotational direction of the drive ring, and the size of the entry hole may be varied based on a position of the drive shaft within the drive shaft hole.
In another general aspect, a camera module includes: a lens barrel accommodating lenses stacked in order in an optical axis direction; and an aperture stop disposed between and aligned with the lenses.
Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
Drawings
Fig. 1 is a perspective view of an aperture stop according to an example.
Fig. 2 is an exploded perspective view of an aperture stop according to an example.
Fig. 3 is a perspective view of the aperture stop of fig. 1 with the cover removed.
Fig. 4A is a sectional view taken along line I-I in fig. 1.
Fig. 4B is a modified version of a sectional view taken along line I-I in fig. 1, and is a sectional view of an aperture stop according to another example.
Fig. 5 is an enlarged view of a portion a in fig. 4.
Fig. 6 is an enlarged view of a portion B in fig. 4.
Fig. 7A, 7B, and 7C are reference diagrams illustrating driving an aperture stop according to an example.
Fig. 8 shows an example of a camera module on which an aperture stop according to an example is mounted.
Fig. 9 is a reference diagram of a camera module associated with camera degradation according to an example.
Like reference numerals refer to like elements throughout the drawings and detailed description. The figures may not be drawn to scale and the relative sizes, proportions and depictions of the elements in the figures may be exaggerated for clarity, illustration and convenience.
Detailed Description
The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. Various changes, modifications, and equivalents of the methods, devices, and/or systems described in this application will, however, become apparent after understanding the disclosure of this application. For example, the order of operations described in this application is merely an example, and is not limited to the order set forth in this application, except to the extent that operations must occur in a particular order, as obvious variations may be made upon understanding the disclosure of this application. In addition, descriptions of features well known in the art may be omitted for the sake of clarity and conciseness.
The features described in this application may be embodied in different forms and should not be construed as limited to the examples described in this application. Rather, the examples described herein are provided merely to illustrate some of the many possible ways of implementing the methods, apparatuses, and/or systems described herein, which will be apparent after understanding the disclosure of the present application.
It should be noted that in this application, the use of the word "may" with respect to an example or embodiment (e.g., with respect to what the example or embodiment may include or implement) means that there is at least one example or embodiment in which such feature is included or implemented, but all examples and embodiments are not limited thereto.
Throughout the specification, when an element such as a layer, region or substrate is described as being "on," "connected to" or "coupled to" another element, it can be directly on, "connected to" or "coupled to" the other element or one or more other elements may be present between the element and the other element. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no other elements intervening between the element and the other element.
As used in this application, the term "and/or" includes any one of the associated listed items as well as any combination of any two or more of the items.
Although terms such as "first", "second", and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections are not limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first member, first component, first region, first layer, or first portion referred to in an example described in this application may also be referred to as a second member, second component, second region, second layer, or second portion without departing from the teachings of the example.
Spatially relative terms such as "above … …," "above," "below … …," and "below" may be used herein for descriptive convenience to describe one element's relationship to another element as illustrated in the figures. These spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to another element would then be "below" or "lower" relative to the other element. Thus, the phrase "above … …" encompasses both an orientation of "above … …" and "below … …" depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this application should be interpreted accordingly.
The terminology used in the present application is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The articles "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, integers, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or groups thereof.
Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may occur. Accordingly, examples described in this application are not limited to the particular shapes shown in the drawings, but include changes in shapes that occur during manufacturing.
The features of the examples described in this application may be combined in various ways that will be apparent after understanding the disclosure of this application. Further, while the examples described in this application have a variety of configurations, other configurations are possible as will be apparent after understanding the disclosure of this application.
Hereinafter, examples will be described with reference to the drawings.
The camera module according to an example may be mounted on automobiles and buildings as well as portable electronic devices such as mobile communication terminals, smart phones, tablet computers, and the like.
Fig. 1 is a perspective view of an aperture stop according to an example, fig. 2 is an exploded perspective view of the aperture stop according to the example, fig. 3 is a perspective view of the aperture stop of fig. 1 with a cover removed, fig. 4A is a cross-sectional view taken along line I-I in fig. 1, fig. 4B is a modified version of the cross-sectional view taken along line I-I in fig. 1 and is a cross-sectional view of the aperture stop according to another example, fig. 5 is an enlarged view of a portion a in fig. 4, and fig. 6 is an enlarged view of a portion B in fig. 4.
Referring to fig. 1 to 6, an
The
The
The first through
The
Light is incident through the
The
Further, the
The
Light is incident through the
In this example, the through
Since the first to
The first to
The
The
A through
The
Even when the
The first to
The first to
Hereinafter, the rotation shaft holes 143, 153, and 163 and the driving
The rotation shaft holes 143, 153, and 163 of the first to
Accordingly, the driving
Since the first to
The fixed
For example, the first to
The entry holes 180 may have a shape repeatedly forming a circular arc in the circumferential direction (when the through
Therefore, light may be incident through one of the incident holes having various sizes depending on the photographing environment.
Referring to fig. 4A, the
The driving
As shown in fig. 4B, the
The size of the
The
In the case of a mobile device, since the driving magnet has a small size, there is no problem of position sensing even when only one position sensor is used. However, in the case of an automobile or the like, since the driving magnet and the driving coil have relatively large sizes, a pair of
Only one
The
When the
When power is applied to the driving
In the present example, the size of the
The
When the
The
Fig. 7A to 7C show driving of the aperture stop (representatively showing the
As shown in fig. 7A, when the driving
As shown in fig. 7B, when the driving
As shown in fig. 7C, when the driving
Referring to fig. 7A to 7C, when the driving
Fig. 8 shows an example of a camera module on which an aperture stop according to an example is mounted.
As shown in fig. 8, a
Fig. 8 shows a structure in which the
Fig. 9 is a reference diagram of a camera module associated with camera degradation according to an example.
As shown in fig. 9, when the exposure time is reduced to prevent image saturation to compensate for a dynamic range such as a large-diameter aperture stop, it may be difficult to achieve LED Flicker Mitigation (LFM).
Accordingly, as shown in fig. 9, in the present disclosure, an iris diaphragm is applied to a camera module. In an environment of high intensity light, a small-diameter diaphragm is applied to reduce the intensity of incident light, and therefore, the exposure time may be longer than the LED blinking period, thereby ensuring LFM performance or preventing image saturation even when a predetermined exposure time level is ensured. In a low-luminance environment, LFM and Wide Dynamic Range (WDR) can be realized by increasing light intensity through a large diameter regardless of the surrounding environment. In addition, a predetermined luminance level can be ensured even in a low-luminance environment.
Therefore, when the
As described above, an apparatus for adjusting an exposure time of a camera to prevent degradation of the camera is provided. Therefore, deterioration of the captured image of the car camera can be reduced.
Further, occurrence of halo at the aperture stop can be prevented. Therefore, deterioration of the captured image of the camera can be further reduced.
While the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail may be made to these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered merely as illustrative and not for purposes of limitation. The description of features or aspects of the disclosure in each example should be considered applicable to similar features or aspects of the disclosure in other examples. Suitable results may also be obtained if the described techniques are performed in a different order and/or if components in the described systems, architectures, devices, or circuits are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure should be defined not by the detailed description but by the claims and their equivalents, and all modifications within the scope of the claims and their equivalents should be understood as being included in the present disclosure.
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