1. A small flexible support structure for a fast reflecting mirror, comprising a bottom, a first connection, a second connection, and a top;

the bottom is a plane structure and is fixed to the base connecting structure;

the top is a plane structure and is fixed to the mirror surface connecting structure;

the first connecting part and the second connecting part are connected with the bottom part and the top part and are arranged in a front-back crossed mode, and the inclination angle is 45 degrees;

the top part is parallel to the bottom part when not acted by driving force, and is transmitted to the first connecting part and the second connecting part when acted by the driving force, and the inclination angles of the first connecting part and the second connecting part are changed to enable the top part to incline.

2. The compact flexible support structure for a fast reflecting mirror according to claim 1, wherein the first connection portion and the second connection portion each have a width half of the width of the bottom portion, and the top portion has the same width as the bottom portion.

3. A compact flexible support structure for a fast reflecting mirror according to claim 1 or 2, wherein the bottom part is bent inwards in its plane along a first direction extension to form the inclined first connection part, the first connection part end part being bent inwards to form a part of the top part;

the bottom part is bent inwards along a first direction opposite direction extension part in the plane of the bottom part to form an inclined second connecting part, and the end part of the second connecting part is bent inwards to form the other part of the top part;

the inner side edge of the first connecting part and the inner side edge of the second connecting part are positioned on the same straight line, and one part of the top formed by the end part of the first connecting part and the other part of the top formed by the end part of the second connecting part are welded to form the top.

4. A compact flexible support structure for a fast reflecting mirror according to claim 1 or 2, wherein the compact flexible support structure material for a fast reflecting mirror has a spring constant E of:

wherein F is the pressure stressed by the small-sized flexible supporting structure material, S is the cross-sectional area of the small-sized flexible supporting structure material, L is the length, Delta L is the elongation, Sigma F is the force stressed by the unit cross-section, and Sigma L is the elongation corresponding to the unit length.

5. A compact flexible support structure for a fast reflecting mirror according to claim 3, wherein the curve of the cartesian equation of the bending radius r-arc of the bend is:

or the parametric equation is expressed as:

wherein t is a polar angle, x and y are respectively a horizontal coordinate and a vertical coordinate of a Cartesian coordinate system, a is a length of a long axis, and b is a length of a short axis.

6. A compact flexible support structure for a fast reflecting mirror according to claim 5, characterized in that the relation of the area A of the top and bottom with the bending radius r is such that:

。

7. a miniature flexible support suspension system for a fast reflective mirror comprising a base attachment structure for attachment to a base, a mirror attachment structure for securing a mirror surface, and a plurality of miniature flexible support structures for a fast reflective mirror as claimed in any one of claims 1 to 6;

a plurality of small-size flexible supporting structures for fast-reflecting mirror along mirror surface connection structure's circumference evenly distributed, be on a parallel with the required every inclined axle of mirror surface and set up a small-size flexible supporting structure or the symmetry sets up two small-size flexible supporting structures, small-size flexible supporting structure's deformation direction is on a parallel with the corresponding inclined axle.

8. A method of forming a compact flexible support structure for a fast reflective mirror as claimed in any one of claims 1 to 6, comprising:

cutting a planar material to form a bottom surface, a first extension and a second extension; the first extension extends in a first direction within the base plane and the second extension extends in a second direction within the base plane;

the first extending part is bent inwards to form an inclined first connecting part, and the end part of the first connecting part is bent inwards to form a part of the top part; the second extending part is bent inwards to form an inclined second connecting part, and the end part of the second connecting part is bent inwards to form the other part of the top part;

welding one portion of the top portion to another portion to form a top portion.

9. The molding method according to claim 8, wherein the cutting is performed by wire cutting, and a rectangle is first formed, the width of the rectangle is the width of the bottom surface, and the length of the rectangle is the sum of three times of the length of the bottom surface and two times of the length of the first connecting part;

selecting the first direction or the reverse direction of the first direction as a feeding direction;

and cutting along the middle line of the length direction, and removing the part of the bottom extending along the first direction and not extending to the first extension part and the part extending along the opposite direction of the first direction and not extending to the second extension part, so that the inner side edge of the first connecting part and the inner side edge of the second connecting part are positioned on the same straight line.

10. The molding method according to claim 9, wherein the bending is performed in a stamping bending manner, a bending line of the bending piece is perpendicular to the direction of the binding, and the relative clean surface is taken as the outer surface of the bending piece; the curve of the cartesian equation for the radius of curvature r arc of the bend is:

or the parametric equation is expressed as:

wherein t is a polar angle, x and y are respectively a horizontal coordinate and a vertical coordinate of a Cartesian coordinate system, a is a length of a long axis, and b is a length of a short axis;

determining a bending radius r according to the areas A of the top and the bottom, wherein the relation between the areas A of the top and the bottom and the bending radius r satisfies the following conditions:

。

Background

The fast reflector is a part working between a light source or a receiver and a target and used for adjusting and stabilizing the visual axis or the light beam direction of an optical system, the deflection direction of the reflector is accurately controlled by adopting a voice coil motor so as to accurately control the deflection angle of the light beam, the fast reflector is used for realizing the fast adjustment of the 'deflection-inclination' azimuth angle of the reflector, and the fast reflector can be used for the visual axis stabilization or the scanning compensation in the field of photoelectricity. The optical fiber is used as a precise optical instrument for controlling the light beam pointing between a light emitting end and a receiving end, integrates light collection, mechanical and electrical technologies, has the advantages of wide system bandwidth, high response speed, high positioning precision, high position resolution and the like, is widely applied to the fields of astronomical telescopes, adaptive optics, image motion compensation, free space optical communication, precise tracking and the like, and becomes a key device for stabilizing light beams and correcting the propagation direction of the light beams in an optical system.

The bearing form of the quick reflector mainly comprises rigid bearing and flexible bearing. Compared with a rigid bearing type quick reflector, the flexible bearing type quick reflector utilizes the deformation of the flexible unit to restrain the degree of freedom of the quick reflector. In order to improve the bandwidth and response speed of the fast reflector system and reduce the influence of friction on the closed loop characteristic of the system, a load supporting mode usually adopts a flexible supporting mode with the advantages of no friction, no backlash, no need of lubrication and the like, and the structural form of the flexible supporting mode comprises a flexible hinge, a flexible flat plate, a flexible shaft and the like. However, since the flexible carrying structure of the fast mirror and the mirror base cannot always be in full contact, a gap may exist between the flexible carrying structure and the mirror base, which is inevitable particularly when the mirror base moves. The presence of such a gap can affect the pointing accuracy of the fast mirror.

In the prior art, the flexible bearing structure of the fast reflector cannot be always in complete contact with the reflector base, and the existence of the gap can influence the pointing accuracy of the fast reflector. An important criterion for a fast mirror is the operating bandwidth, and the component affecting this criterion is the voice coil motor therein, which must have a high output and a short step response time. Conventional fast mirrors typically include four voice coil motors. Two voice coil motors are adopted to form a push-pull type pair in each rotating shaft direction, and smooth and uniform torque is provided for the reflecting mirror.

In order to meet the requirement of pointing accuracy, the flexible bearing structure of the reflector has the problem of large volume, so that the miniaturization of the reflector is influenced. In addition, the manufacturing process of the flexible bearing structure is complex, and the impact vibration resistance is poor.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a small flexible supporting structure for a quick-reflecting mirror and a forming method thereof.

In order to achieve the above object, the present invention provides a small flexible support structure for a fast reflective mirror, comprising a bottom portion, a first connection portion, a second connection portion, and a top portion;

the bottom is a plane structure and is fixed to the base connecting structure;

the top is a plane structure and is fixed to the mirror surface connecting structure;

the first connecting part and the second connecting part are connected with the bottom part and the top part and are arranged in a front-back crossed mode, and the inclination angle is 45 degrees;

the top part is parallel to the bottom part when not acted by driving force, and is transmitted to the first connecting part and the second connecting part when acted by the driving force, and the inclination angles of the first connecting part and the second connecting part are changed to enable the top part to incline.

Further, the widths of the first connecting portion and the second connecting portion are respectively half of the width of the bottom portion, and the width of the top portion is the same as the width of the bottom portion.

Further, the bottom part is bent inwards along a first direction extending part in the plane of the bottom part to form the inclined first connecting part, and the end part of the first connecting part is bent inwards to form a part of the top part;

the bottom part is bent inwards along the first direction opposite direction extension part in the plane of the bottom part to form the inclined second connecting part, and the end part of the second connecting part is bent inwards to form the other part of the top part.

Furthermore, the inner side edge of the first connecting part and the inner side edge of the second connecting part are positioned on the same straight line, and one part of the top part formed by the end part of the first connecting part and the other part of the top part formed by the end part of the second connecting part are welded to form the top part.

Further, the elastic coefficient E of the small flexible support structure material for the fast reflecting mirror is:

wherein F is the pressure stressed by the small-sized flexible supporting structure material, S is the cross-sectional area of the small-sized flexible supporting structure material, L is the length, Delta L is the elongation, Sigma F is the force stressed by the unit cross-section, and Sigma L is the elongation corresponding to the unit length.

Further, the curve of the cartesian equation of the bending radius r arc of the bend is:

or the parametric equation is expressed as:

wherein t is a polar angle, x and y are respectively a horizontal coordinate and a vertical coordinate of a Cartesian coordinate system, a is a length of a long axis, and b is a length of a short axis.

Further, the relation between the area A of the top and the bottom and the bending radius r satisfies:

。

a second aspect provides a compact flexible support suspension system for a fast reflective mirror comprising a base attachment structure for attachment to a base, a mirror attachment structure for securing a mirror surface, and a plurality of said compact flexible support structures for a fast reflective mirror;

a plurality of small-size flexible supporting structures for fast-reflecting mirror along mirror surface connection structure's circumference evenly distributed, be on a parallel with the required every inclined axle of mirror surface and set up a small-size flexible supporting structure or the symmetry sets up two small-size flexible supporting structures, small-size flexible supporting structure's deformation direction is on a parallel with the corresponding inclined axle.

A third aspect provides a method for forming a compact flexible support structure for a fast reflective mirror, comprising:

cutting a planar material to form a bottom surface, a first extension and a second extension; the first extension extends in a first direction within the base plane and the second extension extends in a second direction within the base plane;

the first extending part is bent inwards to form an inclined first connecting part, and the end part of the first connecting part is bent inwards to form a part of the top part; the second extending part is bent inwards to form an inclined second connecting part, and the end part of the second connecting part is bent inwards to form the other part of the top part;

welding one portion of the top portion to another portion to form a top portion.

Further, the cutting adopts a linear cutting mode, firstly, a rectangle is formed, the width of the rectangle is the width of the bottom surface, and the length of the rectangle is the sum of three times of the length of the bottom surface and two times of the length of the first connecting part;

selecting the first direction or the reverse direction of the first direction as a feeding direction;

and cutting along the middle line of the length direction, and removing the part of the bottom extending along the first direction and not extending to the first extension part and the part extending along the opposite direction of the first direction and not extending to the second extension part, so that the inner side edge of the first connecting part and the inner side edge of the second connecting part are positioned on the same straight line.

Furthermore, bending is carried out in a stamping and bending mode, a bending line of the bending piece is perpendicular to the grain binding direction, and the relative clean surface is used as the outer surface of the bending piece; the curve of the cartesian equation for the radius of curvature r arc of the bend is:

or the parametric equation is expressed as:

wherein t is a polar angle, x and y are respectively a horizontal coordinate and a vertical coordinate of a Cartesian coordinate system, a is a length of a long axis, and b is a length of a short axis.

Further, the bending radius r is determined according to the areas A of the top and the bottom, and the relation between the areas A of the top and the bottom and the bending radius r satisfies the following conditions:

。

the technical scheme of the invention has the following beneficial technical effects:

(1) the flexible supporting structure has the advantages of simple production process and mature and reliable processing technology, and greatly reduces the cost required by production.

(2) The invention has small volume, reduces the occupied space as much as possible and can be suitable for a small-sized fast reflecting mirror.

(3) The invention adopts the design of the crossed reeds and is of an integrated structure, so that the shock vibration resistance is greatly improved, and the control bandwidth and the overall reliability of the system are obviously improved.

(4) The supporting structure can realize multidirectional fine angle control through combination; the processing period is short, the yield is high, and the method is suitable for large-scale production; long service life, low failure rate, high stability and reliability.

Drawings

FIG. 1 is a perspective view of a flexible support structure suspension system of the present disclosure;

FIG. 2 illustrates a front view of the flexible support structure after folding of the criss-cross spring design in accordance with the present disclosure;

FIG. 3 illustrates a schematic diagram of the angular variation of a criss-cross spring of a flexible support structure according to the present disclosure;

FIG. 4 is an engineering dimension drawing of a flexible support structure disclosed herein;

FIG. 5 illustrates a top view of a flexible support structure after folding of a criss-cross spring design in accordance with the present disclosure;

FIG. 6 is an elevation view of a suspension system according to the present invention taken along the x-axis;

FIG. 7 is an elevation view of a suspension system according to the present invention taken along the y-axis.

Fig. 8 is a flow chart of a molding method.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

The invention provides a small flexible support structure for a fast reflecting mirror, as shown in figures 1 and 2, the small flexible support structure 1 comprises a bottom part 1-1, a first connecting part 1-2, a second connecting part 1-3 and a top part 1-4.

The bottom 1-1 is a planar structure and is fixed to a base connection structure 3, and the base connection structure 3 is fixed to a base.

The top part 1-4 is a plane structure and is fixed to the mirror surface connecting structure 4, and the connecting structure 4 is a circular ring structure and is used for fixing the mirror surface.

The first connecting part 1-2 and the second connecting part 1-3 are connected with the bottom part 1-1 and the top part 1-4 and are arranged in a front-back cross manner.

The top part 1-4 is parallel to the bottom part 1-1 when not acted by driving force, and is transmitted to the first connecting part 1-2 and the second connecting part 1-3 when acted by driving force, and the inclination angles of the two parts are changed to enable the top part to incline 1-3, which is combined with the figure 3.

Further, the widths of the first connecting portion 1-2 and the second connecting portion 1-3 are half of the width of the bottom portion 1-1, respectively, and the width of the top portion 1-4 is the same as the width of the bottom portion 1-1. A small interval exists between the first connecting part 1-2 and the second connecting part 1-3, and the first connecting part and the second connecting part are not in contact with each other; or a slight contact occurs, resulting in a small frictional force. The bending part of the flexible supporting structure 1 has no relative contact and has small thickness, smooth side surface and small friction force generated by the side edge when bending.

Further, referring to fig. 4, the whole flexible supporting structure is formed by bending and welding a single piece of plane material, the bottom part 1-1 is bent inwards in the plane thereof along a first direction extending part to form the first connecting part 1-2 which is inclined, and the end part of the first connecting part 1-2 is bent inwards to form a part 1-4-1 of the top part.

The bottom part 1-1 is bent inwards in the plane along the first direction opposite direction extension part to form the inclined second connecting part 1-3, and the second connecting part end part 1-3 is bent inwards to form another part 1-4-2 of the top part.

The inner side edge of the first connecting part 1-2 and the inner side edge of the second connecting part 1-3 are located on the same straight line, one part 1-4-1 of the top part formed by the end part of the first connecting part 1-2 and the other part 1-4-2 of the top part formed by the end part of the second connecting part are located on the same plane after being bent, and the top parts 1-4 are formed by welding along connecting lines.

The elastic coefficient E of the small flexible support structure material for the fast reflecting mirror is:

f is the pressure, S is the cross-sectional area, L is the length, Δ L is the elongation, σ F is the stress, i.e., the force applied to a unit cross-section, and σ L is the strain, i.e., the elongation corresponding to a unit length. The flexible support structures are all formed from a single sheet of material. The advantage of this unitary construction is that it avoids the need for joints and the need to weld, braze, bond, and otherwise join the individual parts at such joints.

In one embodiment, the flexible support structure is machined from an Al6061 material so that it has good plasticity and excellent corrosion resistance. The flexible supporting structure has no stress corrosion cracking tendency, and has excellent weldability, corrosion resistance and cold workability.

Furthermore, flexible bearing structure adopts the mode preparation of line cutting, adopts the flexible bearing structure of line cutting processing and compares with interior circle section technology and has that the crookedness is little, the angularity is little, and the depth of parallelism is good, and the gross thickness tolerance discreteness is little, and blade cutting loss is little, and the surface damage layer is shallow, a great deal of advantages such as wafer roughness is little.

Further, the flexible supporting structure obtained by wire cutting is bent along the solid line in fig. 4, and the flexible supporting structure is bent by adopting a stamping and bending process, so that the process has the advantages of high production efficiency, short production period and the like.

Further, the flexible support structure obtained after bending is welded, and the top view is shown in fig. 5 after welding. The welding adopts a brazing process, has the advantages of small deformation, smooth and beautiful joint, and is suitable for welding components which are precise, complex and consist of different materials.

A second aspect of the invention provides a small flexible support suspension system for a fast reflective mirror comprising a base attachment structure 2 for attachment to a base, a mirror attachment structure 4 and a plurality of small flexible support structures 1 for a fast reflective mirror.

The mirror surface connecting structure 4 is a circular ring structure and is used for fixing the mirror surface, transmitting driving force to the capacitive supporting structure 1 and driving the mirror surface to adjust the angle.

The base connecting structure 2 is four supports with oval cross sections, and is fixed to the base to keep the mirror surface stable.

The small flexible supporting structures 1 for the fast reflecting mirror are uniformly distributed along the circumferential direction of the mirror surface connecting structure 4. A plurality of the small flexible supporting structures 1 for the fast reflecting mirror are uniformly distributed along the circumferential direction of the mirror surface connecting structure 4, one small flexible supporting structure is arranged in parallel with each inclined shaft required by the mirror surface or two small flexible supporting structures are symmetrically arranged, and the deformation direction of the small flexible supporting structures is parallel to the corresponding inclined shaft.

In one embodiment, as shown in fig. 6 and 7, 4 small flexible supporting structures 1 are adopted and arranged at intervals of 90 degrees, the deformation direction of the small flexible supporting structures of the first and third fast reflecting mirrors is parallel to the X-axis direction of the plane of the mirror surface, and the deformation direction of the small flexible supporting structures of the second and fourth fast reflecting mirrors is parallel to the Y-axis direction of the plane of the mirror surface. Further, if it is required to realize the inclination in four directions, 8 small flexible supporting structures 1 may be provided, respectively symmetrically arranged in four directions. And so on.

As shown in fig. 6 and 7, the base mounting structure of the suspension system may remain stationary relative to the base while the mirror mounting structure may rotate about the X-axis or the Y-axis relative to the base in accordance with a disclosed embodiment of the invention.

Further, according to other examples of the present disclosure, the number of flexible support structures may be increased in the direction of the tilt axis.

Further, in fig. 6, the flexible support structure is in an intermediate position. In the neutral position, the flexible support structure 1 is parallel to the base mounting structure 2 and parallel to the X-axis of the plane of the mirror. As the flexible support structure bends, it tilts relative to the base mounting structure 2 in a plane perpendicular to the tilt axis X-axis, while the base mounting structure remains parallel to the X-axis. The suspension system behaves like a spring, so the suspension system load-bearing surface will return to a centered or neutral position in the absence of an applied force. Further, the suspension system may allow for deformation of the small flexible support structures of the first and third fast reflective mirrors, providing angular variation in the X-axis direction, allow for deformation of the small flexible support structures of the second and fourth fast reflective mirrors, providing angular variation in the Y-axis direction, while providing relatively lower suspension component friction to allow for higher scanning frequencies. At the same time, the suspension system provides a relatively fixed point of rotation to minimize horizontal movement of the load bearing mirror. For example, the stroke angle along the X and Y axes may be 10. In addition, the suspension system can effectively reduce or eliminate fault points.

A third aspect provides a method for forming a compact flexible support structure for a fast reflective mirror, comprising, in combination with fig. 8, the steps of:

(1) cutting a planar material to form a bottom surface 1-1, a first extension and a second extension; the first extension extends in a first direction within the base plane and the second extension extends in a second direction within the base plane.

The cutting adopts a linear cutting mode, firstly a rectangle is formed, the width of the rectangle is the width of the bottom surface, and the length of the rectangle is three times of the length of the bottom surface plus two times of the length of the first connecting part.

Selecting the first direction or the reverse direction of the first direction as a feeding direction; and cutting along the middle line of the length direction, and removing the part of the bottom extending along the first direction and not extending to the first extension part and the part extending along the opposite direction of the first direction and not extending to the second extension part, so that the inner side edge of the first connecting part and the inner side edge of the second connecting part are positioned on the same straight line.

The pattern produced by cutting is shown in plan view in fig. 4. And selecting the x direction as a feeding direction, wherein the machining instruction is L, and the numerical value behind the L represents the value of a quadrant in which the starting point of the line segment is used as the origin of coordinates and the end point of the machining line segment is located. In the processing process, a little margin is required to be left for the blank material so as to ensure the quality of the processed product. The flexible supporting structure after processing has the advantages of small bending degree, small warping degree, good parallelism, small total thickness tolerance discreteness, small cutting loss of the cutting edge, shallow surface damage layer, small surface roughness of the wafer and the like.

(2) The first extending part is bent inwards to form an inclined first connecting part 1-2, and the end part of the first connecting part 1-2 is bent inwards to form a part 1-4-1 of the top part; the second extending part is bent inwards to form an inclined second connecting part 1-3, and the end part of the second connecting part 1-3 is bent inwards to form the other part 1-4-2 of the top part.

Further, the flexible supporting structure obtained by wire cutting is bent along the solid line in fig. 2, so as to obtain the three-dimensional structure shown in fig. 3. The flexible supporting structure is bent by adopting a stamping and bending process, the bending line of the bending piece is perpendicular to the grain binding direction, the relative clean surface is used as the outer surface of the bending piece, and the outer layer tension crack is reduced. The size of the bending radius can influence the change of the section of the deformation area and the resilience condition after bending forming. The cartesian equation curve of the upper and lower curved lines of the bend is:

can be expressed as:

wherein t is a polar angle, x and y are respectively a horizontal coordinate and a vertical coordinate of a Cartesian coordinate system, a is a length of a long axis, and b is a length of a short axis. For a given arc, a, b are constant values, and when a = b, the curve of the equation is circular.

Along with the increase of r, the areas of the upper surface and the lower surface are gradually increased, and the relationship between the areas of the upper surface and the lower surface and the bending radius is as follows:

the bending radius is thus determined according to the desired bottom area.

(3) One part 1-4-1 and the other part 1-4-2 of the top part are welded to form the top part 1-4.

And further, welding the bent flexible support structure. The brazing process is adopted, oil stains, oxides, burrs and sundries on the surface and the joint of a weldment need to be removed before welding, the end part of a copper pipe and the joint surface of the copper pipe are ensured to be clean and dry, and the brazing filler metal needs to be ensured to be clean and dry. And (5) after cleaning, checking the cleanliness and the dryness of the surface of the weldment. The flexible supporting structure has the advantages of small deformation, smooth and beautiful joint, and suitability for welding precise and complex members made of different materials. The flexible supporting structure is convenient to process, and low-cost and small-volume manufacturing can be realized.

Furthermore, grooves for positioning are formed in the mirror surface connecting structure and the base connecting structure, and the upper surface and the lower surface of the flexible supporting structure are placed in the grooves for positioning and welding. The flexible support structure X intersection is located at the geometric center of the structure. The integral flexible support structure can rotate within a range of +/-10 degrees. The elastic coefficient E of the flexible support structure is:

in summary, the present invention relates to a small flexible support structure for a fast reflective mirror and a method for forming the same. A small flexible support structure comprising a bottom, a first connection, a second connection, and a top; the bottom is a plane structure and is fixed to the base connecting structure; the top is a plane structure and is fixed to the mirror surface connecting structure; the first connecting part and the second connecting part are connected with the bottom and the top and are arranged in a front-back crossed manner; the top part is parallel to the bottom part when not acted by the driving force, and is transmitted to the two connecting parts when acted by the driving force, and the inclination angles of the two parts are changed to enable the top part to incline. The flexible supporting structure has the advantages of simple production process and mature and reliable processing technology, and greatly reduces the cost required by production. The invention has small volume, reduces the occupied space as much as possible and can be suitable for a small-sized fast reflecting mirror. The invention adopts the design of the crossed reeds and is of an integrated structure, so that the shock vibration resistance is greatly improved, and the control bandwidth and the overall reliability of the system are obviously improved.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.