KR100481522B1 - Structure for fixing lens - Google Patents

Abstract

A lens fixing structure in which the lens barrel 31 can be easily mounted using a plurality of elastic brackets 54 and 58 is disclosed. The lens fixing structure according to the present invention includes a barrel holder (50) for elastically supporting the lens barrel (31) in at least two axial directions perpendicular to each other, wherein the barrel holder (50) is an outer circumferential surface of the lens barrel (31). The mounting portion 53, which is a reference when assembling, and the lens barrel 31 seated on the seating portion 53 to restrain the radial flow of the lens barrel 31 are elastic toward the seating portion 53. And a first elastic bracket 54 for supporting, a support protrusion 57 and a second elastic bracket 58 for elastically supporting the lens barrel 31 in the longitudinal direction so as to suppress the axial flow of the lens barrel 31. do. According to this, since the lens barrel 31 is elastically supported by the plurality of elastic brackets 54 and 58, the assembly process of the product is simplified at the time of assembly, and the defect rate is also reduced, and the shock transmitted from the outside to the lens barrel is reduced. There is an effect that can elastically suppress the flow of the lens barrel.

Description

Structure for fixing lens

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly, to a lens fixing structure for fixing a condensing lens unit for condensing light incident from the outside so as to form an image on an imaging device included in an imaging optical system of an image reading apparatus. will be.

In general, an image reading apparatus includes an image pickup device such as an electronic coupling element and a condenser lens unit, and is adopted in a digital image pickup device such as a digital camera to convert an image of a subject into an electric signal. In this case, the image reading apparatus further including an exposure lamp may be used in an office equipment for copying a coated object such as a copying machine, a scanner and outputting an image.

The condensing lens unit includes a cylindrical lens barrel, and the lens barrel is fixed to the frame of the image reading apparatus by the barrel holder, which will be described below with reference to the accompanying drawings.

1 is a side cross-sectional view schematically showing a conventional lens barrel coupling structure.

As shown in FIG. 1, a plurality of lenses 13 for condensing incident light are provided inside the cylindrical lens barrel 11, and the lens barrel 11 is fixed to a frame (not shown). It is inserted into the mounting hole 16 of the holder 15.

Conventionally, a male screw portion 11a is formed outside the lens barrel 11 and a female screw portion 16a corresponding to the male screw portion 11a is formed on the inner circumference of the mounting hole 16. As the male screw portion 11a is screwed into the female screw portion 16a, the lens barrel 11 is screwed with the mounting hole 16, and the lens barrel 11 mounted to the mounting hole 16 is rotated. The focus of the image formed on the image pickup device (not shown) can be adjusted by moving in the mounting hole 16 in the direction of the arrow A shown in FIG. 1. The lens barrel 11 after the focal length between the lens barrel 11 and the image pickup device is adjusted is fixed to maintain the adjusted focal length by the small screw 14 press-fitted through the barrel holder 15. .

However, the imaging optical system 10 having such a lens fixing structure has a problem in that threads are formed on the outer surface of the lens barrel 11 and the lens holder 15 when the product is assembled. When the screw thread is formed, the outer surface of the lens barrel 11 may be damaged, and the inner surface of the lens barrel 11 may be damaged depending on the damage of the outer surface of the lens barrel 11. If the inner surface of the lens barrel 11 is damaged in this way, it may adversely affect the optical path condensed by the image pickup device, and thus there is a problem in that an image formed on the image pickup device is not accurately formed.

Then, when the small screw 14 presses one point of the outer circumferential surface of the lens barrel 11, a phenomenon occurs in which the entire lens barrel 11 is driven in one direction in the mounting hole 16, so that the focus of light that is focused is focused on the imaging device. It may not be located precisely in the center of.

Accordingly, there is a problem that data of the image is not output correctly from the image reading apparatus.

In addition, when an impact is transmitted from the outside to the image reading apparatus as in the case of transportation of a product adopting the image reading apparatus configured as described above, the impact is transmitted to the lens barrel 11 and the barrel holder 15 as it is, so that the lens barrel ( 11) the lens barrel 11 is damaged, or there is a problem that the image is not accurately formed in the image pickup device.

The present invention has been made to solve the above problems, and the object of the present invention is to provide a lens fixing structure of an imaging optical system whose structure is improved so that the assembly of the product is improved and the focus of the image formed on the image pickup device is not changed. have.

In the lens fixing structure of the present invention for achieving the above object, the lens fixing structure including a cylindrical lens barrel having a plurality of lenses and a barrel holder to which the lens barrel is mounted, the radial flow of the lens barrel And first elastic fixing means for elastically supporting the outer circumferential surface of the lens barrel so as to be suppressed, and second elastic fixing means for elastically supporting either side of the lens barrel in the axial direction to suppress axial flow of the lens barrel. .

According to this, it is not necessary to process the thread on the outer surface of the lens barrel, it is possible to simplify the assembly process during production of the product, there is an effect that can reduce the defective rate of the lens barrel.

In addition, the shock transmitted from the outside to the lens barrel is alleviated, and when the lens barrel is moved by the impact, the lens barrel can be returned to its original position by the elastic fixing means, so that the focus of the image formed on the image pickup device can be moved. There is also an advantage that can be suppressed.

According to a preferred embodiment of the present invention, the barrel holder is provided with a seating portion for supporting a portion of the outer peripheral surface adjacent to the lower and lower ends of the lens barrel, the first elastic fixing means is installed on the barrel holder, between the lens barrel And a first elastic bracket mounted on top of the seat and elastically pressing the lens barrel toward the seat.

The second elastic fixing means is attached to the barrel holder to be in contact with the other end of the lens barrel and the support protrusion protruding from the bottom surface of the barrel holder to be in contact with one end of the lens barrel seated on the seating portion. And a second elastic body elastically pressed toward the support protrusion side.

Here, it is preferable that the first elastic bracket is an elastic body that is bent to extend the coupling portion coupled to the seating portion at both ends.

In addition, according to another aspect of the present invention, the first elastic bracket, the contact portion is bent and extended at both ends of the coupling portion coupled to the seating portion, the elastic piece protruding so that the lens barrel and the end contact from one side of the contact portion It is preferable to include.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exploded perspective view illustrating a structure of an imaging optical system, FIG. 3 is a perspective view illustrating a state in which a lens barrel is mounted on a barrel holder, and FIGS. 4 and 5 are cross-sectional views of the imaging optical system.

As shown, the imaging optical system 20 of the image reading apparatus includes a condensing lens unit 30, an imaging unit 40, and a barrel holder 50.

The imaging unit 40 includes an imaging device 41 and a support 43 for supporting the imaging device 41. The imaging device 41 performs a function of converting image information of incident light into an electrical signal and outputting the electrical signal.

The condensing lens unit 30 is for condensing light incident from the outside to form an image on the imaging device 41. The condensing lens barrel 31 and its lens barrel 31 having open ends are formed. It is installed inside and includes a plurality of lenses 33 for collecting the external light. Here, the lens barrel 31 is provided spaced apart from the imaging element 41 at intervals equal to the focal length of the image formed on the imaging element 41. The imaging device 41 is, of course, arranged on the optical axis X of the light projected from the condensing lens unit 30.

The barrel holder 50 is formed on the frame 70 and includes a first mounting part 51 and a second mounting part 60. The first mounting unit 51 is for fixing the condenser lens unit 30 on the frame 70 of the image reading apparatus, and the second mounting unit 60 mounts the imaging unit 40 on the barrel holder 50. It is for fixing. Here, the imaging unit 40 is not limited to being mounted on the barrel holder 50, but may be directly installed in the frame 70. In this case, the barrel holder 50 may be omitted from the second mounting unit 60. Of course.

Even if the condenser lens unit 30 is moved by an external impact or the like, the first mounting unit 51 according to the present exemplary embodiment may return the lens to its original position so that the image formed on the imaging device 41 is not shaken or the focal point is not changed. 31) elastically support. In order to perform such a function, the first mounting portion 51 includes elastic fixing means for elastically supporting the lens barrel 31 in a plurality of axial directions perpendicular to each other, wherein the elastic fixing means includes first elastic fixing means ( 52) and second elastic fixing means (56).

The first elastic fixing means 52 is elastically supported while surrounding the outer circumferential surface of the lens barrel 31, and includes a seating portion 53 and the first elastic bracket 54, the lens barrel 31 in its radial direction Support with.

The seating part 53 is formed to protrude from the bottom surface of the barrel holder 50 so as to surround and support a lower portion and a side portion of the lens barrel 31. Here, the seating portion 53 is formed so that the distance between both sides is greater than the diameter of the lens barrel 31 to facilitate assembly of the product, so that a gap is formed between the lens barrel 31 and the seating portion 53. It is preferable.

The first elastic bracket 54 is coupled to the upper portion of the seating portion 53, and the lens barrel 31 is installed in a space between the first elastic bracket 54 and the seating portion 53. Here, the first elastic bracket 54 is formed in a plate shape with a contact portion 54a formed at a central portion thereof, and a coupling portion 54b for coupling with the barrel holder 50 is formed at both ends of the contact portion 54a. The coupling part 54b is coupled to the first support part 50b formed on both sides of the seating part 53 by a predetermined fastening member 71. Accordingly, the inner surface of the contact portion 54a and a portion of the outer surface of the lens barrel 31 make line contact or surface contact. Here, the first elastic bracket 54 may be formed of various materials, and in particular, when the first elastic bracket 54 is formed of an elastic body having elastic force, the lens barrel 31 may be moved toward the seating part 53 only by the first elastic bracket 54 itself. It may be elastically pressed and fixed. On the other hand, the first elastic bracket 54 and the seating portion 53 is not necessarily limited to the same structure as in the present embodiment, the seating portion 53 supports the lower and / or side surfaces of the lens barrel 31 A part of the inner surface of the contact portion 54a and the outer surface of the lens barrel 31 come into contact with each other so that the first elastic bracket 54 can press the lens barrel 31 toward the seating portion 53 in various ways. Implementation will be possible. In the present embodiment, the contact portion 54a may be formed in a rectangular shape. Alternatively, the contact portion 54a may be modified in various ways such that its shape may be formed in a circular shape.

In addition, the first elastic fixing means 52 further suppresses the flow of the lens barrel 31 mounted on the barrel holder 31, and at the same time, further includes an elastic piece 55 for elastically fixing the lens barrel 31. Include. The elastic piece 55 protrudes from an inner surface of the contact portion 54a facing the lens barrel 31, and the elastic piece 55 contacts the lens barrel 31 when the first elastic bracket 54 is mounted. The lens barrel 31 is elastically pressed in the lateral direction of the seating portion 53 in contact with the lens barrel 31 in a direction different from the supporting direction of 54a. According to this, when the shock is transmitted from the outside during the assembly or transportation of the product to the lens barrel 31 mounted with a predetermined clearance with the mounting portion 53, the lens barrel 31 tries to flow as much as the clearance, but the hidden line in FIG. As shown in FIG. 5, the lens barrel 31 may be elastically suppressed by the elastic piece 55. On the other hand, the elastic piece 55 can be variously modified according to the structure of the first elastic bracket 54. If the contact portion 54a of the first elastic bracket 54 is formed in a circular shape so as to correspond to the shape of the outer circumferential surface of the lens barrel 31, and is formed of an elastic body having an elastic force as a whole, the lens barrel may be omitted even if the elastic piece 55 is omitted. At the same time as fixing the elastically (31) it will be possible to perform the function of preventing the flow of the lens barrel (31).

The second elastic fixing means 56 is for elastically supporting the lens barrel 31 in the longitudinal direction parallel to the optical axis X, that is, in the axial direction of the lens barrel 31. The second elastic fixing means 56 in the present embodiment is a support projection 57 protruding from the bottom surface of the barrel holder 50 to a predetermined length so as to support the rear of the lens barrel 31 and the lens barrel 31. It includes a second elastic bracket 58 is installed on the barrel holder 50 to support the front of the.

The support protrusion 57 is in contact with the rear lower end of the lens barrel 31 close to the imaging device 41 when the lens barrel 31 is seated on the mounting portion 53. At this time, the support protrusion 57 is formed to protrude from the bottom surface of the barrel holder 50 to a height capable of supporting only the bottom rear surface of the lens barrel 31 so as not to obstruct the path of the light collected by the lens 33.

The second elastic bracket 58 is installed in the barrel holder 50 to elastically support the front lower end of the lens barrel 31. The second elastic bracket 58 in the present embodiment is fixed to the barrel holder 50 by being mounted in the insertion groove 50a formed on the bottom surface of the barrel holder 50, and the insertion groove 50a is the lens barrel 31. ), That is, the front side of the seating portion 53 of the bottom surface of the barrel holder (50). The end of the second elastic bracket 58 is in contact with the front lower end of the lens barrel 31 in the state in which it is mounted in the insertion groove 50a, and the lens barrel 31 is provided with the second elastic bracket 58 and the support protrusion. It is elastically supported by the 57 in the direction parallel to the optical axis X. According to the second elastic fixing means 56 configured as described above, it is possible to elastically suppress the flow of the lens barrel 31 in the direction parallel to the optical axis (X). In this case, the second elastic bracket 58 and the support protrusion 57 may be installed at opposite positions. If the second elastic bracket 58 and the support protrusion 57 may satisfy only the length of the lens barrel 31, the shape and the installation position may be satisfied. Can be modified in various ways.

On the other hand, the second mounting portion 60 is a space between the plurality of side walls 50c protruding from the outer surface of the barrel holder 50 in the space between the barrel holder 50 and the image pickup device 41 and the side wall 50c. And a portion 50d. The side wall 50c extends from the coupling portion 50b toward the imaging unit 40, and the support 43 of the imaging unit 40 is mounted on the upper surface. The space portion 50d is connected from the lens barrel 31 to the imaging device 41 so that the light collected through the lens barrel 31 can reach the imaging device 41.

Here, the support 43 of the imaging unit 40 is coupled to the side wall 50c through a plurality of sliding grooves 44 formed in a part of the support 43 in contact with the side wall 50c and the sliding groove. The fastening means 72 is provided on the side wall 50c so as to be slidable in a direction parallel to the optical axis X, as indicated by arrow B in FIG. 2. According to this, in installing the imaging unit 40 to the barrel holder 50, the support 43 is temporarily coupled to the side wall 50c, and then the support 43 is slid in the same direction as the optical axis X to capture the image. After the focal length of the image formed on the element 41 is adjusted, the fastening means 72 is completely coupled to the side wall 50c to fix the image unit 40 while adjusting the focus of the image formed on the image sensing element 41. Can be.

On the other hand, the lens fixing structure in this embodiment is not necessarily limited to this embodiment, the shape and installation position of the first and second elastic brackets 54, 58 can be variously modified. The first and second elastic brackets 54 and 58 which are deformed in this manner only need to satisfy the lens barrel 31 to be elastically supported in the lateral direction and the longitudinal direction.

According to the lens fixing structure of this invention comprised as mentioned above, the lens barrel 31 for condensing external light on the imaging element 41 is parallel with the optical axis X by the elastic fixing means of the barrel holder 50. As shown in FIG. It is elastically supported and fixed in the axial direction and the axial direction orthogonal to the optical axis (X). Accordingly, the lens barrel 31 can be fixed not only without fixing the lens barrel 31 to the lens barrel 31 to fix the lens barrel 31, but also a small screw 14 (see FIG. 1). Since it is not necessary to force the press, the assembly process of the product is simplified, there is an effect that the failure rate is also reduced.

In addition, when the lens barrel 31 is elastically supported, the shock transmitted from the outside can be buffered, and when the lens barrel 31 flows due to an external impact, the image formed on the image pickup device 41 may be out of focus. Even if it occurs, the lens barrel 31 has the effect of returning itself to the original position by the elastic fixing means 52, 56.

As mentioned above, although the preferred embodiment for illustrating the principle of this invention was shown and demonstrated, this invention is not limited to the structure and operation as it was shown and described. Rather, those skilled in the art will appreciate that various changes and modifications can be made to the present invention without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

1 is a side cross-sectional view showing a conventional lens fixing structure.

Figure 2 is an exploded perspective view showing the structure of the imaging optical system of the image reading apparatus according to the present invention.

3 is a perspective view illustrating a state in which the lens barrel of FIG. 2 is fixed to the barrel holder;

4 is a cross-sectional view taken along the line IV-IV of FIG.

FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 3; FIG.

Explanation of symbols on the main parts of the drawings

20: imaging optical system 30: condensing lens unit

31: lens barrel 33: condenser lens

40: imaging unit 41: imaging device

43: support 44: sliding groove

50: barrel holder 51: first mounting portion

52: first elastic fixing means 53: seating portion

54: first elastic bracket 55: elastic piece

56: second elastic fixing means 57: support protrusion

58: second elastic bracket 60: second mounting portion

70 frame 71, 72 fastening means

Claims (5)

A cylindrical lens barrel including a plurality of lenses; A barrel holder having a seating portion supporting a lower side of an outer circumferential surface of the lens barrel; First elastic fixing means for suppressing flow along the radial direction of the lens barrel by being installed in the barrel holder to elastically press the outer circumferential surface of the lens barrel exposed to the outside of the barrel holder toward the barrel holder side; One side is fixed to the lens barrel to contact the rear end of the lens barrel along the axial direction of the lens barrel, and the other side is in contact with the front end of the lens barrel to elastically press the front end to the rear end side. And a second elastic fixing means for suppressing axial flow of the lens barrel. The method of claim 1, The seating portion is formed in a shape surrounding a portion of the outer circumferential surface of the lens barrel, The first elastic fixing means is mounted to the barrel holder to be in contact with at least two points of the outer peripheral surface of the lens barrel exposed to the outside of the barrel holder, the first to prevent the lens barrel from being separated from the seating portion Lens fixing structure, characterized in that it comprises an elastic bracket. The method of claim 2, The first elastic bracket is a lens fixing structure, characterized in that the coupling portion coupled to the barrel holder is an elastic body formed by bending both ends. The method of claim 2, The first elastic bracket, A contact part contacting with an outer circumferential surface of the lens barrel exposed to an upper end of the barrel holder in at least one point by any one of a line contact and a surface contact; A coupling part formed at both ends of the contact part by bending and coupled to the barrel holder; And And an elastic piece integrally protruding from the contact portion toward the lens barrel. The elastic piece is in contact with another portion spaced apart from the contact portion of the lens barrel and the contact portion of the lens barrel of the outer peripheral surface of the lens barrel exposed to the outside of the barrel holder to elastically fix the lens barrel in the radial direction of the lens barrel. Lens fixing structure, characterized in that the pressing. The method of claim 1, wherein the second elastic fixing means, A support protrusion protruding from a bottom surface of the barrel holder to be in contact with one end of the lens barrel seated on the seating portion; And And a second elastic bracket mounted to the barrel holder to be in contact with the other end of the lens barrel and elastically pressing the lens barrel toward the support protrusion.