TWI883331B - Lens device - Google Patents

Abstract

A lens device includes a first optical element, a movable frame, a first frame, a second optical element and an aperture. The movable frame is moved in a direction parallel to an optical axis. The first optical element is disposed on the movable frame. The second optical element is disposed on the first frame. The aperture is disposed between the movable frame and the first frame. The first optical element, the aperture and the second optical element are sequentially arranged along the optical axis from an object side to an image side.

Description

Lens device

The present invention relates to a lens device.

As consumers have higher requirements for lens quality, the pixel size is getting smaller and smaller, and even very small dust or particles in the lens can be easily captured. In the past, the lens structure could not prevent dust or particles generated by the mechanism from falling on the infrared cutoff filter and the light sensing element, causing dark spots or dark blocks in the captured image, which seriously affected the image quality.

In view of this, the present invention provides a lens device to solve the above problems.

The lens device of the present invention includes a first optical element, a movable frame, a first frame, a second optical element and an aperture. The movable frame moves along a direction parallel to an optical axis, and the first optical element is arranged on the movable frame. The second optical element is arranged on the first frame. The aperture is arranged between the movable frame and the first frame. The first optical element, the aperture and the second optical element are arranged in sequence from an object side to an image side along the optical axis.

In one embodiment, the lens device further includes a filter and a light sensing element, wherein the first frame is integrally formed and covers the filter and the light sensing element.

In one embodiment, the lens device further includes a second frame, a fixed frame and a third optical element, wherein the third optical element is disposed on the fixed frame, the second frame surrounds the aperture and the fixed frame, and the aperture and the fixed frame both extend toward the inner wall of the second frame, and the aperture is closer to the inner wall of the second frame than the fixed frame.

In one embodiment, the second frame is not formed integrally with the first frame, or the fixed frame is not formed integrally with the first frame.

In one embodiment, the first optical element, the third optical element, the aperture, the second optical element, the filter and the light sensing element are arranged in sequence along the optical axis from the object side to the image side, the movable frame is arranged beside the first optical element and surrounds the intersection of the first optical element and the optical axis, the fixed frame is arranged beside the third optical element and surrounds the intersection of the third optical element and the optical axis, the aperture surrounds the optical axis, and the first frame is arranged beside the second optical element and surrounds the intersection of the second optical element and the optical axis.

In one embodiment, the lens device further includes a light sensing element, wherein the first frame is disposed beside the second optical element and surrounds the intersection of the second optical element and the optical axis, the light sensing element and the aperture are disposed on different sides of the second optical element, and the movable frame is disposed beside the first optical element and surrounds the intersection of the first optical element and the optical axis.

In one embodiment, the third optical element has a vertex, which is closer to the first optical element than other parts of the third optical element, the aperture has a light entrance hole, and the lens device meets at least one of the following conditions: 0.27≦H ₂₃₀ /H ₂₆₀ ≦0.90, 17.80mm≦D ₂₃₀ ≦20.75mm, 22mm≦L ₂₆₀ ≦27mm, 19mm≦W ₂₆₀ ≦24mm, 0.20≦H ₂₄₀ /H ₂₆₀ ≦4.3, 14.35mm≦D ₂₄₀ ≦14.45mm, 0.48≦D1/D2≦0.50, D ₂₄₀ <L ₂₆₀ , D ₂₄₀ <W ₂₆₀ , wherein H ₂₃₀ is the height of the movable frame, H ₂₆₀ is the height of the first frame, D ₂₃₀ is the outer diameter of the movable frame, L ₂₆₀ is the length of the first frame, W ₂₆₀ is the width of the first frame, H ₂₄₀ is the height of the fixed frame, D ₂₄₀ is the outer diameter of the fixed frame, D1 is the distance between the vertex and the light entrance hole, and D2 is the distance between the light entrance hole and the filter.

2: Lens device

200: Circuit board

210: Second frame

220: Guide rod

230: Movable frame

231: First group

240: Fixed frame

241: Second lens group

250: aperture

251: Light entry hole

260: First frame

261: The third lens group

270: Infrared cut-off filter

280: Light sensing element

290: Bracket

D1, D2: distance

D ₂₃₀ , D ₂₄₀ : outer diameter

H ₂₃₀ , H ₂₄₀ , H ₂₆₀ : Height

L ₂₆₀ : Length

OA: optical axis

P:Vertex

W ₂₆₀ : Width

Figure 1 is a top view of a lens device according to one embodiment of the present invention.

Figure 2 is a cross-sectional view of the lens device in Figure 1 along II-II.

Figure 3 is a cross-sectional view of the lens device in Figure 1 along the plane III-III.

Figure 4 is a three-dimensional cross-sectional view of the lens device in Figure 1 along III-III.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a top view of a lens device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the lens device along II-II of FIG. 1. As shown in the figure, the lens device 2 includes a first lens group 231, a second lens group 241, an aperture 250, a third lens group 261, an infrared cut-off filter 270, and a light sensing element 280 arranged in sequence along the optical axis OA from the object side (light incident side) to the image side (light sensing side). It is worth noting that when the lens device is used, in most cases, the lens device 2 shown in FIG. 2 is used flat (rotated about 90 degrees to the left or right), and the following description will not specifically emphasize this. The configuration and function of each component of this embodiment are described in detail below. It can be understood that the first lens group 231, the second lens group 241 and/or the third lens group 261 can be replaced by optical components such as lenses, prisms and/or reflectors, and the infrared cut-off filter 270 can also be replaced by different filters as needed. The first lens group 231 is the first optical component, the second lens group 241 is the third optical component, and the third lens group 261 is the second optical component, which will not be described in detail below.

The first lens group 231 may include one or more lenses (one lens is shown as a representative in the figure, but the present invention is not limited thereto), and is supported or connected by a movable frame 230, and the movable frame 230 is sleeved on the guide rod 220. The so-called support here means that the movable frame 230 is arranged beside the first lens group 231 and surrounds the intersection of the first lens group 231 and the optical axis OA, but is not limited thereto. In other embodiments, no matter what angle the lens device 2 is placed at (horizontally, vertically, or tilted, etc.), as long as the lenses can be attached to or connected to the movable frame 230, it will suffice. During operation, the movable frame 230 can slide along the guide rod 220, so the first lens group 231 is a movable lens group. It is worth noting that since the extension direction of the guide rod 220 is parallel to the optical axis OA, the guide rod 220 can be regarded as a linear guide rod, which can make the position limit of the first lens group 231 simple and clear, and has the advantages of stability and small deviation. When the movable frame 230 moves along the guide rod 220, the guide rod 230 can also be regarded as moving along a direction parallel to the optical axis OA.

The second lens group 241 may include one or more lenses (two lenses are shown as a representative in the figure, but the present invention is not limited thereto), and is supported or connected by a fixed frame 240. The fixed frame 240 will not move relative to the optical axis, so the second lens group 241 is a fixed lens group. In this embodiment, the fixed frame 240 is arranged beside the second lens group 241 and surrounds the intersection of the second lens group 241 and the optical axis OA, but the above-mentioned arrangement is not limited thereto.

The aperture 250 includes a plurality of blades, which are driven by a stepping motor (not shown). The number of driving steps can control the position of the blades, and further control the aperture size of the light-entering hole 251 (shown in FIG. 4) to determine the amount of light entering. The aperture 250 surrounds the optical axis OA.

The lens device 2 of the present invention further includes a second frame 210 and a first frame 260, wherein the aperture 250 is disposed between the movable frame 230 and the first frame 260. The second frame 210 surrounds the movable frame 230 (including the first lens group 231), the fixed frame 240 (including the second lens group 241), and the aperture 250, that is, the second frame 210 is located on the other side of the movable frame 230 (including the first lens group 231), the fixed frame 240 (including the second lens group 241), and the aperture 250 relative to the optical axis. It is worth noting that the aperture 250 and the fixed frame 240 both extend toward the inner wall of the second frame 210 (the side of the second frame 210 close to the optical axis), but the aperture 250 is closer to the inner wall of the second frame 210 than the fixed frame 240. Specifically, except for the light entrance hole 251 in the middle, the other parts of the aperture 250 extend as close to the second frame 210 as possible, which can be used to intercept dust passing through the fixed frame 240 and the second frame 210 or particles generated by the movable frame 230 when moving, effectively forming the first dust prevention measure.

The first frame 260 and the second frame 210 are connected to form the outer shell of the lens device 2, and the second frame 210 and the first frame 260 are not formed in one piece. In addition, the first frame 260 has a group frame function in addition to the outer shell function, that is, it is used to support or connect the third lens group 261. The third lens group 261 may include one or more lenses (four lenses are shown as a representative in the figure, but the present invention is not limited thereto). The first frame 260 is disposed beside the third lens group 261 and surrounds the intersection of the third lens group 261 and the optical axis OA. It is further explained that a portion of the first frame 260 extends away from the optical axis and connects to the second frame 210, and another portion surrounds the third lens group 261 to form a space for accommodating optical elements, and the portion close to the photosensitive side is tightly connected to a bracket 290, for example but not limited to being sealed with full-circle adhesive. Since the first frame 260 will not move relative to the optical axis, the third lens group 261 is a fixed lens group.

The infrared cut filter (IR-Cut Filter) 270 is supported or connected by the bracket 290 and is used to filter infrared rays, but allows visible light to pass through and reach the light sensing element 280. In actual applications, other filters can be used as needed.

The photosensitive element 280 is mounted on the circuit board 200 and is used to convert the received optical signal into an electrical signal and then output it. The bracket 290 is connected to the circuit board 200 so that there is no air gap between the outer periphery of the bracket 290 away from the optical axis and the outer periphery of the circuit board 200 away from the optical axis. In other embodiments, the bracket 290 can also be a frame with a housing structure, so that the filter, the photosensitive element and the circuit board can be set therein.

It is worth noting that the first frame 260 is an integrally formed part, completely covering the infrared cut-off filter 270 and the light sensing element 280. The said covering means that the first frame 260 can completely cover the infrared cut-off filter 270 and the light sensing element 280 from the object side to the image side except for the holes through which light can pass, so as to serve as the second (and main) dust prevention measure. It is also worth noting that the fixed frame 240 and the first frame 260 are not integrally formed, but are different parts separated from each other.

As can be seen from the above description, the present invention designs the lens structure into a front and rear group form, and uses the aperture 250 as the first dust prevention measure in the front group (i.e., the first lens group 231 and the second lens group 241), and uses the integrally formed first frame 260 to completely cover or fully cover the infrared cut-off filter 270 and the photosensitive element 280 in the rear group (i.e., the third lens group 261) as the second dust prevention measure, so that dust in the lens or particles generated by the mechanism operation can be effectively prevented from falling on the infrared cut-off filter 270 and the photosensitive element 280, thereby helping to improve the image quality.

The above can achieve the basic action and effect. The following details are helpful to optimize the above dustproof effect: Please refer to Figure 2 and Figure 3 at the same time. Figure 3 is a cross-sectional view of the lens device along III-III in Figure 1. In this embodiment, the height H ₂₆₀ of the first frame 260 satisfies 1.03mm≦H ₂₆₀ ≦21.45mm, and the height H ₂₆₀ is preferably 12.95mm±0.05mm, the length L ₂₆₀ of the first frame 260 satisfies 22mm≦L ₂₆₀ ≦27mm, and the width W ₂₆₀ satisfies 19mm≦W ₂₆₀ ≦24mm. Such a design enables the first frame 260 to provide an area required to completely cover the infrared cut-off filter 270 and the light sensing element 280, thereby achieving the purpose of sealing and dustproofing.

The height H230 of the movable frame ₂₃₀ satisfies 5.92mm≦ _H230 ≦5.98mm, and the height _H230 is preferably 5.95mm. The outer diameter _D230 satisfies 17.80mm≦ _D230 ≦20.75mm, and the outer diameter _D230 is preferably 19.6mm±0.05mm. It is worth noting that if the length of the guide rod 220 is increased, the height _H230 of the movable frame 230 can be increased to 9.14mm±0.03mm. The ratio of the height of the movable frame 230 to the height of the first frame 260 is 0.27≦ _H230 / _H260 ≦9.0, preferably 0.46≦ _H230 / _H260 ≦0.7

The height H ₂₄₀ of the fixing frame 240 satisfies 4.325 mm ≤ H ₂₄₀ ≤ 4.425 mm, and the height H ₂₄₀ is preferably 4.375 mm. The outer diameter D ₂₄₀ satisfies 14.35 mm ≤ D ₂₄₀ ≤ 14.45 mm, and the outer diameter D ₂₄₀ is preferably 14.4 mm. The ratio of the height H240 of the fixed frame ₂₄₀ to the height H260 of the first frame ₂₆₀ satisfies 0.2≦ _H240 / _H260 ≦4.3, so that the first frame 260 can fully isolate the infrared cut filter 270 and the light sensing element 280 from the aperture 250 and the movable frame 230 above, effectively preventing dust or foreign objects from falling on the infrared cut filter 270 and the light sensing element 280. In addition, the outer diameter _D240 of the fixed frame 240 is smaller than the length _L260 (i.e., _D240 < _L260 ) and/or the width _W260 (i.e., _D240 < _W260 ) of the first frame 260, which can effectively reduce the space and achieve a dust-proof state.

Please refer to FIG. 4, which is also a cross-sectional view of the lens device of FIG. 1 along line III-III. Unlike FIG. 3, FIG. 4 is a three-dimensional view, while FIG. 3 is a plan view. As shown in the figure, the second lens group 241 has a vertex P, and the vertex P is closer to the first lens group 231 than other parts of the second lens group. The aperture 250 has a light entrance hole 251. In this embodiment, the distance D1 between the vertex P and the light entrance hole 251 satisfies 5.59mm≦D1≦5.69mm, and the distance D1 is preferably 5.64mm. The distance D2 between the light entrance hole 251 and the top surface of the infrared cut-off filter 270 satisfies 11.57mm≦D2≦11.67mm, and the distance D2 is preferably 11.62mm. D1/D2 satisfies 0.48≦D1/D2≦0.50. The advantage of this configuration ratio is the average space utilization rate, so that the first mirror group 231 can obtain the maximum movable range.

Although the present invention has been disclosed in the form of implementation as above, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

2: Lens device

200: Circuit board

210: Second frame

220: Guide rod

230: Movable frame

231: First group

240: Fixed frame

241: Second lens group

250: aperture

260: First frame

261: The third lens group

270: Infrared cut-off filter

280: Light sensing element

290: Bracket

L ₂₆₀ : Length

OA: optical axis

Claims (10)

A lens device includes: a first optical element; a movable frame, the movable frame moves along a direction parallel to an optical axis, the first optical element is arranged on the movable frame; a first frame; a second optical element, the second optical element is arranged on the first frame; an aperture, the aperture is arranged between the movable frame and the first frame; a third optical element; a fixed frame; wherein the first optical element, the third optical element, the aperture and the second optical element are arranged in sequence from an object side to an image side along the optical axis; wherein the third optical element is arranged on the fixed frame. The lens device as described in item 1 of the patent application scope further includes a filter and a light sensing element, wherein the first frame is integrally formed and covers the filter and the light sensing element. The lens device as described in item 2 of the patent application further includes a second frame, wherein the second frame surrounds the aperture and the fixed frame, and the aperture and the fixed frame both extend toward the inner wall of the second frame, and the aperture is closer to the inner wall of the second frame than the fixed frame. The lens device as described in item 3 of the patent application scope, wherein the second frame and the first frame are not integrally formed, or the fixed frame and the first frame are not integrally formed. The lens device as described in item 3 of the patent application, wherein the first optical element, the third optical element, the aperture, the second optical element, the filter and the light sensing element are arranged in sequence along the optical axis from the object side to the image side, the movable frame is arranged beside the first optical element and surrounds the intersection of the first optical element and the optical axis, the fixed frame is arranged beside the third optical element and surrounds the intersection of the third optical element and the optical axis, the aperture surrounds the optical axis, and the first frame is arranged beside the second optical element and surrounds the intersection of the second optical element and the optical axis. The lens device as described in item 1 of the patent application scope further includes a light sensing element, wherein the first frame is arranged beside the second optical element and surrounds the intersection of the second optical element and the optical axis, the light sensing element and the aperture are arranged on different sides of the second optical element, and the movable frame is arranged beside the first optical element and surrounds the intersection of the first optical element and the optical axis. A lens device as described in any one of items 1 to 6 of the patent application scope, wherein the third optical element has a vertex, the vertex is closer to the first optical element than other parts of the third optical element, the aperture has a light entrance hole, and the lens device meets at least one of the following conditions: 0.27≦H ₂₃₀ /H ₂₆₀ ≦0.90, 17.80mm≦D ₂₃₀ ≦20.75mm, 22mm≦L ₂₆₀ ≦27mm, 19mm≦W ₂₆₀ ≦24mm, 0.20≦H ₂₄₀ /H ₂₆₀ ≦4.3, 14.35mm≦D ₂₄₀ ≦14.45mm, 0.48≦D1/D2≦0.50, D ₂₄₀ <L ₂₆₀ , D ₂₄₀ <W ₂₆₀ , wherein H ₂₃₀ is the height of the movable frame, H ₂₆₀ is the height of the first frame, D ₂₃₀ is the outer diameter of the movable frame, L ₂₆₀ is the length of the first frame, W ₂₆₀ is the width of the first frame, H ₂₄₀ is the height of the fixed frame, D ₂₄₀ is the outer diameter of the fixed frame, D1 is the distance between the vertex and the light entrance hole, and D2 is the distance between the light entrance hole and the filter. A lens device comprises: a first optical element; a movable frame, the movable frame moves along a direction parallel to an optical axis, the first optical element is arranged on the movable frame; a first frame; a second optical element, the second optical element is arranged on the first frame; an aperture, the aperture is arranged between the movable frame and the first frame; wherein the first optical element, the aperture and the second optical element are arranged in sequence from an object side to an image side along the optical axis; wherein the lens device satisfies at least one of the following conditions: 0.27≦H ₂₃₀ /H ₂₆₀ ≦0.90, 17.80mm≦D ₂₃₀ ≦20.75mm, 22mm≦L ₂₆₀ ≦27mm, 19mm≦W ₂₆₀ ≦24mm, wherein H ₂₃₀ is the height of the movable frame, H ₂₆₀ is the height of the first frame, D ₂₃₀ is the outer diameter of the movable frame, L ₂₆₀ is the length of the first frame, and W ₂₆₀ is the width of the first frame. The lens device as described in item 8 of the patent application further includes a filter, a light sensing element, a second frame, a fixed frame and a third optical element, wherein the first frame is integrally formed and covers the filter and the light sensing element, the third optical element is arranged on the fixed frame, the second frame surrounds the aperture and the fixed frame, and the aperture and the fixed frame both extend toward the inner wall of the second frame, and the aperture is closer to the inner wall of the second frame than the fixed frame. The lens device as described in item 9 of the patent application, wherein the first optical element, the third optical element, the aperture, the second optical element, the filter and the light sensing element are arranged in sequence along the optical axis from the object side to the image side, the movable frame is arranged beside the first optical element and surrounds the intersection of the first optical element and the optical axis, the fixed frame is arranged beside the third optical element and surrounds the intersection of the third optical element and the optical axis, the aperture surrounds the optical axis, and the first frame is arranged beside the second optical element and surrounds the intersection of the second optical element and the optical axis.

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