Small medium-wave infrared continuous zoom lens structure

Abstract

The utility model relates to a small medium-wave infrared continuous zoom lens structure. The small medium-wave infrared continuous zoom lens structure is characterized by comprising a front fixed lens, a zoom lens, a compensation lens, a focusing lens, a reflector and a rear fixed lens group, the front fixed lens, the zoom lens, the compensation lens and the focusing lens are respectively composed of an optical lens; the rear fixed lens group comprises three groups of lenses; according to the utility model, the zooming and focusing functions of the optical system are realized by adopting a cam curve mode; the optical lens is not provided with a baffle plate for view field correction, but adopts a focusing pull virtual imaging mode for view field correction. Meanwhile, the optical lens has the advantages of small size and light weight.

Description

Technical Field

[0001] The utility model belongs to the technical field of optics, machinery and electricity, and in particular relates to the structure of a compact medium-wave infrared continuous zoom lens. Background Art

[0002] In recent years, medium-wave infrared has been widely used in industrial detection, military reconnaissance, environmental testing and other fields, so weight and volume have become the primary considerations for designers.

[0003] The distance between the lenses of the current medium-wave infrared zoom lenses is relatively large, and the overall size of the lenses is relatively long, which affects some of the adaptability range.

[0004] For example, the Chinese patent "A high-transmittance medium-wave infrared zoom lens", publication number CN106054364B, includes a front fixed group, a magnification group, a compensation group, a first rear fixed group, a second rear fixed group and a detector, which are distributed in sequence along the optical axis from the object side to the image side. It is characterized in that: it adopts a positive meniscus lens, a double concave negative lens, a double convex positive lens, a positive meniscus lens and two positive meniscus lenses respectively; the magnification group and the compensation group are driven by a driving mechanism to move forward and backward to respectively change the focal length and compensate for the defocus of the image plane. Although this invention can realize the zoom function of the medium-wave infrared lens, the distance between the lenses is large, and the overall size of the lens is long, which is not suitable for installation in equipment with a small space. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a compact medium-wave infrared continuous zoom lens structure, which has a compact size and can be installed in equipment with a small space.

[0006] The utility model is a compact medium-wave infrared continuous zoom lens structure, which is characterized by:

[0007] It includes a front fixed lens, a magnification lens, a compensating lens, a focusing lens, a reflector and a rear fixed lens group; the front fixed lens, magnification lens, compensating lens and focusing lens are all composed of a single optical lens; the rear fixed lens group includes three groups of lenses; the spacing between the front fixed lens and the magnification lens is 3.2 to 13.1 mm; the spacing between the magnification lens and the compensating lens is 2.3 to 18.2 mm; the spacing between the compensating lens and the focusing lens is 3.3 to 11.8 mm; the spacing between the focusing lens and the first rear fixed lens group is 28.66 mm; the spacing between the first rear fixed lens group and the second rear fixed lens group is 7.63 mm; the spacing between the second rear fixed lens group and the third rear fixed lens group is 1.22 mm; the optical axes of the front fixed lens, magnification lens, compensating lens and focusing lens are perpendicular to the optical axis of the rear fixed lens group.

[0008] Preferably, the front fixed lens is fixed in the main lens barrel by a front fixed lens pressure ring, the magnification lens is installed in the magnification slide to form a magnification assembly, and the compensation lens is installed in the compensation slide to form a compensation assembly, and the magnification assembly and the compensation assembly are both installed in the main lens barrel; the main lens barrel is provided with guide straight grooves for magnification and compensation; the magnification assembly and the compensation assembly are fixed with a zoom guide pin assembly by means of a threaded connection, and the zoom guide pin assembly cooperates with the guide straight groove on the main lens barrel; the zoom cam is connected to the main lens barrel through a steel ball to form a rolling bearing, and the zoom cam is provided with a magnification curved groove, and the zoom guide pin assembly passes through the magnification curved groove and the guide straight groove from the outside to the inside in turn and is connected and fixed to the magnification assembly or the compensation assembly.

[0009] Preferably, the zoom motor assembly, zoom potentiometer assembly and zoom limit switch assembly constitute an electric zoom mechanism;

[0010] The gear of the zoom motor assembly meshes with the gear on the zoom cam. When the zoom motor rotor rotates in the positive or negative direction, it drives the zoom cam to rotate accordingly. Through the cooperation of the zoom curve groove, compensation curve groove and zoom guide pin assembly, the zoom assembly and compensation assembly are driven to change from rotational motion to linear motion, thereby realizing the zoom function of the lens.

[0011] Preferably, the engagement of the zoom cam with the gear of the zoom potentiometer assembly causes the zoom potentiometer assembly to rotate relative to one another; the zoom limit pin is placed on the zoom cam and follows the rotation of the zoom cam, and the zoom cam angle is limited by the combined action of the zoom limit switch assembly and the zoom limit pin.

[0012] Preferably, the focusing assembly includes a focusing lens, a reflecting mirror and a rear fixed lens group; the focusing lens is installed in the zoom lens barrel to form a focusing lens group, and the focusing lens group is installed inside the focusing main lens barrel; two guide straight grooves are evenly distributed on the focusing main lens barrel, and the focusing cam is installed on the outer peripheral side of the focusing main lens barrel. The focusing cam is circumferentially provided with two linear oblique grooves evenly distributed at 180°, and the focusing guide pin passes through the linear oblique grooves and the guide straight grooves from the outside to the inside in sequence and is fixedly connected to the focusing lens group.

[0013] Preferably, the focusing potentiometer assembly, the focusing motor assembly, the focusing main barrel, the focusing cam and the focusing limit assembly constitute an electric focusing mechanism; the focusing motor assembly gear is engaged with the focusing cam gear, and the focusing motor assembly is energized to rotate, driving the focusing cam to rotate through the gears. The rotation of the focusing lens group is restricted by the straight groove on the focusing main barrel so that it only makes linear motion within the straight groove, thereby realizing the focusing function of distant and near targets.

[0014] Preferably, the focusing potentiometer assembly gear is engaged with the focusing cam gear, and when the focusing cam rotates, it rotates synchronously with the focusing potentiometer gear; the focusing limit pin is placed on the focusing cam and follows the rotation of the focusing cam, and the rotation angle of the focusing cam is limited by the joint action of the focusing limit assembly and the focusing limit pin.

[0015] The medium-wave infrared continuous zoom lens of the utility model has the characteristics of compact structure and miniaturization.

[0016] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the optical system of an embodiment of the present patent;

[0018] Figure 2 This is a schematic diagram of the structural system of the embodiment of this patent;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure of the zoom assembly in the embodiment of the present patent;

[0020] Figure 4 yes Figure 3 Left view of;

[0021] Figure 5 This is a stereoscopic diagram of the zoom assembly in the embodiment of the present patent;

[0022] Figure 6 This is a schematic diagram of the cross-sectional structure of the focusing assembly in the embodiment of the present patent;

[0023] Figure 7 yes Figure 6 Left view

[0024] Figure 8 This is a three-dimensional diagram of the focusing assembly in the embodiment of this patent;

[0025] Figure 1 Middle: A-front fixed lens; B-zoom lens; C-compensating lens; D-focusing lens; E-reflecting mirror; F-rear fixed lens group;

[0026] Figure 2 Middle: 10-zoom assembly; 20-focusing assembly; 30-rear fixed assembly;

[0027] Figure 3 、 4 In the middle, 101-front fixed lens; 102-zoom assembly; 103-main lens barrel; 104-zoom cam; 105-zoom cam pressure ring; 106-compensation assembly; 107-zoom guide pin assembly; 108-zoom motor assembly; 109-zoom limit switch assembly; 110-zoom potentiometer assembly.

[0028] Figure 6 、 7 201-focusing motor assembly; 202-focusing potentiometer assembly; 203-focusing limit assembly; 204-focusing lens group; 205-focusing main lens barrel; 206-focusing cam; 207-focusing cam pressure ring; 208-reflector; 209-rear fixing group. DETAILED DESCRIPTION

[0029] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0030] Figure 1 The optical system diagram shown in this patent mainly includes a front fixed lens A, a zoom lens B, a compensating lens C, a focusing lens D, a reflector E and a rear fixed lens group F; the front fixed lens A, the zoom lens B, the compensating lens C and the focusing lens D are all composed of a single optical lens; the rear fixed lens group includes three groups of lenses.

[0031] Among them, the interval between the front fixed lens A and the zoom lens B is 3.2 to 13.1 mm; the interval between the zoom lens B and the compensating lens C is 2.3 to 18.2 mm; the interval between the compensating lens C and the focusing lens D is 3.3 to 11.8 mm; the interval between the focusing lens D and the rear fixed lens group F1 is 28.66 mm; the interval between the rear fixed lens group F1 and the rear fixed lens group F2 is 7.63 mm; the interval between the rear fixed lens group F2 and the rear fixed lens group F3 is 1.22 mm; the optical axes of the front fixed lens A, zoom lens B, compensating lens C and focusing lens D are perpendicular to the optical axis of the rear fixed lens group F.

[0032] The front fixed lens A is a positive meniscus lens; the zoom lens B is a biconcave negative lens; the compensation lens C is a biconvex positive lens; the focusing lens D is a negative meniscus lens; the rear fixed lens group F includes a biconvex positive lens, a negative meniscus lens and a negative meniscus lens in sequence.

[0033] Figure 2 This is a structural diagram shown in this patent, which mainly consists of a zoom component 10, a focusing component 20 and a rear fixed component 30.

[0034] Zoom assembly 10 Figure 3 、 4As shown, the front fixed lens 101 is fixed in the main lens barrel 103 by a front fixed lens pressure ring, the zoom lens B is installed in the zoom slide to form a zoom assembly 102, and the compensation lens C is installed in the compensation slide to form a compensation assembly 106. After the assembly is completed, it is installed by grinding with the main lens barrel 103; the main lens barrel 103 is evenly provided with guide grooves for zoom and compensation; the zoom assembly 102 and the compensation assembly 106 are fixed with a zoom guide pin assembly 107 by means of threaded connection, and the zoom guide pin assembly 107 cooperates with the guide groove on the main lens barrel 103; the zoom cam 104 is connected to the main lens barrel 103 by a steel ball. The rolling bearing, that is, the zoom cam 104, can rotate relative to the main lens barrel 103, and the zoom cam pressure ring 105 limits the axial movement of the zoom cam 104, together forming a zoom assembly 10; the zoom cam 104 is provided with a magnification curve groove, and the zoom guide pin assembly 107 passes through the magnification curve groove and the guide straight groove from the outside to the inside in sequence and is connected and fixed to the magnification assembly 102 or the compensation assembly 106. The zoom guide pin assembly 107 connects the zoom cam 103 with the magnification assembly 102 and the compensation assembly 106 together, and the zoom motor assembly 108, the zoom potentiometer assembly 110 and the zoom limit switch assembly 109 constitute an electric zoom mechanism.

[0035] The gears of the zoom motor assembly 108 mesh with the gears on the zoom cam 104. When the zoom motor rotor rotates positively or negatively, it drives the zoom cam 104 to rotate accordingly. This, through the zoom curve groove, the compensation curve groove, and the zoom guide pin assembly 107, drives the zoom assembly 102 and the compensation assembly 106 to move according to the optical design requirements. Two straight grooves on the main barrel 103 act as constraints on the zoom guide pin assembly 107, converting the rotational motion of the zoom assembly 102 and the compensation assembly 106 into linear motion, thereby achieving the zoom function of the system lens. When the focal length of the system changes, the meshing of the zoom cam 104 and the gears of the zoom potentiometer assembly 110 causes the zoom potentiometer assembly 110 to rotate relative to each other, causing the resistance value of the potentiometer to change. The changed value of the potentiometer can be determined by an appropriate sampling circuit and transmitted to the controller, thereby displaying the zoom value. Conversely, the controller issues a corresponding resistance value command, enabling real-time control of the focal length.

[0036] The zoom limit pin is placed on the zoom cam 104 and follows the rotation of the zoom cam 104 . The zoom limit switch assembly 109 and the zoom limit pin work together to limit and protect the rotation angle of the zoom cam 104 .

[0037] Focusing components such as Figure 6 、 7As shown, it mainly includes a focusing lens D, a reflecting mirror E and a rear fixed lens group F; the focusing lens D is installed in the zoom lens barrel to form a focusing lens group 204, which is installed inside the focusing main lens barrel 205 after assembly; two guide straight grooves are evenly distributed on the focusing main lens barrel 205, and a focusing cam 206 is installed on the outer peripheral side of the focusing main lens barrel 205. The focusing cam 206 is circumferentially provided with two linear oblique grooves evenly distributed at 180°. The focusing guide pin passes through the linear oblique grooves and the guide straight grooves from the outside to the inside in sequence and is fixedly connected to the focusing lens group 204; the focusing potentiometer assembly 202, the focusing motor assembly 201, the focusing main lens barrel 205, the focusing cam 206, and the focusing limit assembly 203 in the figure constitute an electric focusing mechanism; the focusing motor assembly 20 The gear 1 of the focus motor assembly 201 meshes with the gear of the focus cam 206. When the focus motor assembly 201 is powered on and rotated, the gear drives the focus cam 206 to rotate. The straight groove on the focus main lens barrel 205 restricts the rotation of the focus lens group 204 so that it only moves linearly within the straight groove, thereby achieving the function of focusing on distant and near targets. The gear of the focus potentiometer assembly 202 meshes with the gear of the focus cam 206. When the focus cam 206 rotates, it synchronously rotates relative to the focus potentiometer gear, causing the resistance of the potentiometer to change. The changed value of the potentiometer can be calculated through an appropriate sampling circuit and transmitted to the controller, thereby realizing the display of the focus value. Conversely, the controller can issue a corresponding resistance value command to achieve real-time control of the focus.

[0038] The focus limiting pin is placed on the focus cam 206 and follows the rotation of the focus cam 206 . The focus limiting assembly 203 and the focus limiting pin work together to limit and protect the focus cam 206 at the corner.

[0039] The optical lens does not have a baffle for field of view correction, but adopts the method of focusing and virtual imaging to perform field of view correction; at the same time, the optical lens has the advantages of small size and light weight.

[0040] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A compact medium-wave infrared continuous zoom lens structure, characterized by: The lens assembly comprises a front fixed lens (A), a zoom lens (B), a compensating lens (C), a focusing lens (D), a reflector (E) and a rear fixed lens group (F); the front fixed lens (A), the zoom lens (B), the compensating lens (C) and the focusing lens (D) are all composed of a single optical lens; the rear fixed lens group comprises three groups of lenses; the spacing between the front fixed lens (A) and the zoom lens (B) is 3.2 to 13.1 mm; the spacing between the zoom lens (B) and the compensating lens (C) is 2.3 to 18.2 mm; the compensating lens The spacing between the front fixed lens (A), zoom lens (B), compensating lens (C) and focusing lens (D) is 3.3 to 11.8 mm; the spacing between the focusing lens (D) and the first rear fixed lens group (F1) is 28.66 mm; the spacing between the first rear fixed lens group (F1) and the second rear fixed lens group (F2) is 7.63 mm; the spacing between the second rear fixed lens group (F2) and the third rear fixed lens group (F3) is 1.22 mm; the optical axes of the front fixed lens (A), zoom lens (B), compensating lens (C) and focusing lens (D) are perpendicular to the optical axis of the rear fixed lens group (F).

2. The compact medium-wave infrared continuous zoom lens structure according to claim 1, characterized in that: The front fixed lens (A) is fixed in the main lens barrel (103) by the front fixed lens pressing ring, the zoom lens (B) is installed in the zoom slide to form a zoom assembly (102), the compensation lens (C) is installed in the compensation slide to form a compensation assembly (106), the zoom assembly (102) and the compensation assembly (106) are both installed in the main lens barrel (103); the main lens barrel (103) is provided with a guide straight groove for zooming and compensation; the zoom assembly (102) and the compensation assembly (106) are ... ) is fixedly provided with a zoom guide pin assembly (107) by means of a threaded connection, and the zoom guide pin assembly (107) cooperates with the guide straight groove on the main lens barrel (103); the zoom cam (104) is sleeved with the main lens barrel (103) through a steel ball to form a rolling bearing, and the zoom cam (104) is provided with a zoom curve groove, and the zoom guide pin assembly (107) passes through the zoom curve groove and the guide straight groove from the outside to the inside in sequence and is connected and fixed to the zoom assembly (102) or the compensation assembly (106).

3. The compact medium-wave infrared continuous zoom lens structure according to claim 2, characterized in that: The zoom motor assembly (108), the zoom potentiometer assembly (110) and the zoom limit switch assembly (109) constitute an electric zoom mechanism; The gear of the zoom motor assembly (108) is meshed with the gear on the zoom cam (104). When the zoom motor rotor rotates in the positive and negative directions, the zoom cam (104) is driven to rotate accordingly. The zoom component (102) and the compensation component (106) are driven to change from rotational motion to linear motion through the zoom curve groove, the compensation curve groove and the zoom guide pin assembly (107), thereby realizing the zoom function of the lens.

4. The compact medium-wave infrared continuous zoom lens structure according to claim 3, characterized in that: The zoom cam (104) is engaged with the gear of the zoom potentiometer assembly (110), causing the zoom potentiometer assembly (110) to rotate relative to the zoom cam (104); a zoom limit pin is arranged on the zoom cam (104), follows the rotation of the zoom cam (104), and limits the rotation angle of the zoom cam (104) through the combined action of the zoom limit switch assembly (109) and the zoom limit pin.

5. The compact medium-wave infrared continuous zoom lens structure according to claim 3, characterized in that: The focusing assembly comprises a focusing lens (D), a reflecting mirror (E) and a rear fixed lens group (F); the focusing lens (D) is installed in the zoom lens barrel to form a focusing lens group (204), and the focusing lens group (204) is installed in the interior of the focusing main lens barrel (205); two guide straight grooves are evenly distributed on the focusing main lens barrel (205), a focusing cam (206) is installed on the outer peripheral side of the focusing main lens barrel (205), and the focusing cam (206) is circumferentially provided with two linear oblique grooves evenly distributed at 180 degrees, and a focusing guide pin passes through the linear oblique grooves and the guide straight grooves in sequence from the outside to the inside and is fixedly connected to the focusing lens group (204).

6. The compact medium-wave infrared continuous zoom lens structure according to claim 5, characterized in that: The electric focusing mechanism is composed of a focusing potentiometer assembly (202), a focusing motor assembly (201), a focusing main lens barrel (205), a focusing cam (206), and a focusing limit assembly (203); the gear of the focusing motor assembly (201) is engaged with the gear of the focusing cam (206); the focusing motor assembly (201) is energized to rotate, and the focusing cam (206) is driven to rotate by the gear; the rotation of the focusing lens group (204) is restricted by the straight groove on the focusing main lens barrel (205), so that the focusing lens group (204) only performs linear motion within the straight groove, thereby realizing the focusing function of the near and far targets.

7. The compact medium-wave infrared continuous zoom lens structure according to claim 6, characterized in that: The gear of the focus potentiometer assembly (202) is meshed with the gear of the focus cam (206). When the focus cam (206) rotates, it rotates synchronously with the focus potentiometer gear. The focus limiting pin is arranged on the focus cam (206) and follows the rotation of the focus cam (206). The focus limiting pin limits the rotation angle of the focus cam (206) through the combined action of the focus limiting assembly (203) and the focus limiting pin.

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