various embodiments will be described in detail with reference to the drawings , where like reference numerals represent like parts and assemblies throughout the several views . reference to various embodiments does not limit the scope of the invention , which is limited only by the scope of the claims attached hereto . additionally , any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the claimed invention . throughout the specification and claims , the following terms take at least the meanings explicitly associated herein , unless the context clearly dictates otherwise . the meanings identified below are not intended to limit the terms , but merely provide illustrative examples for use of the terms . the meaning of “ a ,” “ an ,” and “ the ” may include reference to both the singular and the plural . the meaning of “ in ” may include “ in ” and “ on .” the term “ coupled ” can mean a direct connection between items , an indirect connection through one or more intermediaries , or communication between items in a manner that may not constitute a connection . briefly stated , the present disclosure generally relates to observing blood flow in a capillary vessel . an apparatus for observing blood flow in a capillary vessel is arranged having a first length that extends from an objective lens to an image sensor , so that a focus point of the light passing through the magnification ratio adjustor 922 is focused upon the image sensor . however , because it is difficult , in practice , to assemble the optics processing and imaging component with sufficiently strict tolerances , an error may occur with respect to a first length “ l ” ( see fig6 , for example ) that extends from the objective lens to the image sensor . accordingly , when a user changes a magnification ratio with the magnification ratio adjustor ( such as when zooming in or out ), a shift of a focus point may result which causes the desired image to be out of focus . conventional methods often include an additional focusing step which is conducted by moving of an optics processing and imaging component in an up or down direction . however , this operation provides a distraction and requires extra care for dealing with the tedious operation of maintaining focus . fig1 is a perspective view that illustrates an apparatus for observing blood flow of capillary vessels . fig2 illustrates a top view of the apparatus . fig3 illustrates a side view from arrow iii of fig1 . fig4 illustrates a side view from arrow iv of fig1 . fig5 illustrates a side view from arrow v of fig1 . in an embodiment , an apparatus 1 comprises a light source 2 for illuminating a fingertip with light , and an optics imaging and processing component 3 for producing an enlarged image of the fingertip . the enlarged image allows blood flow in a capillary vessel at the fingertip to be observed by a health care provider , for example , viewing a display ( not shown ). the optics imaging and processing component 3 in the embodiment comprises a lens - barrel ; a magnification ratio adjustor having an objective lens that is provided at the lower end of the lens - barrel 31 and an imaging component having an image sensor ( such as a ccd , a cmos sensor , and the like ) and being provided at the upper end of the lens - barrel . the lens - barrel 31 comprises an interval adjustment mechanism 7 that is disposed between the imaging component and the lens - barrel in order to adjust the interval therebetween . the interval adjustment mechanism 7 is arranged such that the focus point can be easily maintained when zooming using the interval adjustment mechanism . optical processing / imaging component 3 is mounted to vertical pole 42 with supporting arm 5 , the vertical pole 42 being provided on base 41 in a vertical direction . illuminator 2 is mounted on the base 41 with mounting arm 6 . the optics processing and imaging component 3 , as shown in fig6 ( which is a partly - sectional view of the whole part of the component ), is configured to have a lens - barrel with a cavity of the inside , magnification ratio adjustor 32 with a objective lens ( not shown in figures ), and imaging component 33 with ccd 331 ( as discussed above other imaging sensors can be used ). the example apparatus in various embodiments further comprises interval adjustment mechanism 7 in optical processing / imaging component 3 . as shown in fig6 and 7 ( which is an enlarged view of part a from fig6 ), the interval adjustment mechanism 7 is provided between lens - barrel 31 and imaging component 33 so that the interval x can be adjusted . interval adjustment mechanism 7 comprises lower cylinder 71 that is attached to lens - barrel 31 , and upper cylinder 72 that is attached to imaging component 33 . upper cylinder 72 is threadably mounted onto the outer surface of lower cylinder 71 ( for example , through a spiral screw mechanism ) so that the upper cylinder can move in a longitudinal direction ( as shown by arrow b ) as it rotates in relation to lower cylinder 71 . in other words , interval adjustment mechanism 7 can be configured to alter interval x by rotating upper cylinder 72 . section 70 is helically driven . both cylinders 71 and 72 are designed not to obstruct light passing from magnification ratio adjustor 32 to a sensor , such as ccd 331 . in the embodiment , a first interval l from the object lens of magnification ratio adjustment 32 to ccd 331 is adjustable to match with a reference interval by adjusting interval x by using interval adjustment mechanism 7 . the term “ reference interval ” references the interval that extends from an objective lens to a sensor , which is determined in its design so that a focus point of the light passing through magnification ratio adjustor 32 is focused upon the sensor . in many cases , the apparatus 1 has an error in dimension l when assembled ( due to imprecise tolerances , for example ). the manufacturing error can be corrected by adjusting interval x by using interval adjustment mechanism 7 . fig8 illustrates a side view of supporting arm 5 . fig9 illustrates an exploded perspective view of fig8 . arrows in fig9 indicate a y - axis direction , an x - axis direction , and a z - axis direction . the x - axis is one of the horizontal directions , the y - axis is another horizontal direction that is perpendicular to the x - axis direction ( and that defines a horizontal plane comprising the x and y axes ), and z - axis is the vertical direction . supporting arm 5 includes a first stage 51 , a second stage 52 , a third stage 53 , and a forth stage 54 . supporting arm 5 is mounted on vertical pole 42 with the first stage 51 and also supports optics processing and imaging component 3 with the forth stage 54 . the first stage 51 has an aperture 511 into which vertical pole 42 can be inserted . first stage 51 can be affixed to vertical pole 42 inserted through the penetration hole 511 by tightening first knob 512 , and can also be rotatably mounted in a horizontal direction and moved up and down by loosening first knob 512 . the first stage 51 also has a second knob 513 and a third knob 514 . the first stage 51 further has a first recessed portion ( or concave ) 515 that generally extends in the z - axis direction . the first recessed portion typically has a wider bottom than its opening . the second stage 52 has a first convex portion 512 stretching in the z - axis direction , the shape of which slideably fits that of the first recessed portion 515 of the first stage 51 , and a second convex portion 522 extending in the x - axis direction . both the convex portions 512 and 522 typically have wider top surfaces than the bottom surfaces . the third stage 53 has a second recessed portion 531 stretching in the x - axis direction , and a third recessed portion 532 stretching in the y - axis direction . both recessed portions 531 and 532 have wider bottoms than their openings . the shape of the second recessed portion 531 slideably fits that of the second convex portion 522 . the third stage 53 has a forth knob 533 and a fifth knob 534 . the forth stage 54 has an aperture 541 for holding the optics processing and imaging component 3 . stage 54 also has a third convex portion 542 , the shape of which slideably fits that of the third recessed portion 532 of the third stage 53 . accordingly , first , second , third and forth stages 51 - 54 can be coupled to supporting arm 5 as an assembly when the first convex portion 521 and the first recessed portion 515 are joined together , the second convex portion 522 and the second recessed portion 531 are joined together , and the third convex portion 542 and the third recessed portion 532 are joined together . the z - axis stage can be coupled to the first convex portion 521 to allow rotation of an axis ( not shown in figures ) of the second and third knobs 513 and 514 as a rack and pinion mechanism . the second knob 513 can have a smaller number of pinions than that of the third knob 514 ( those pinions are not shown in figures ). the x - axis stage can be provided with a linkage of the convex portion 522 to rotation of an axis ( not shown ) of the forth knob 533 as a rack and pinion mechanism . the y - axis stage can be provided with a linkage of the third convex portion 542 to rotation of an axis ( not shown ) of the fifth knob 534 as a rack and pinion mechanism . in the example structures of the supporting arm 5 , second stage 52 moves along the z - axis direction in relation to the first stage 51 as the second knob 513 or the third knob 514 is rotated . the third stage 53 moves along the x - axis direction in relation to the second stage 52 as the forth knob is rotated , and the stage part 54 moves along the y - axis direction in relation to the third stage 53 as the fifth knob 534 is rotated . with respect to adjustment using the second and third knobs 513 and 514 , a rotation of the third knob 514 can provide a smaller amount of the movement in the z - axis direction as compared to the amount of rotation provided by the second knob . fig1 illustrates a sectional view of illuminator 2 . in an embodiment , illuminator 2 comprises a housing body 21 , a light source 22 provided in the housing 21 , an opening 23 for emitting the light from the light source 22 to the outside of the housing 21 through a condensing lens 231 , and a fan 24 and air inlet 25 for exhausting heat of the inside of the housing 21 to the outside . the opening 23 typically has an aperture mechanism of the passing light ( not shown ). on the opposite side to the opening a coating of mirror surface is applied . the light source 22 can be , for example , a high pressure mercury lamp . the illuminator 2 is mounted on the base 41 with a mounting arm 6 as shown in fig1 . the mounting arm has two ball joints 61 , 62 , and a 360 degree - rotatable axis 63 provided between the two ball joints . the ball joint 61 is also coupled with an edge 64 that can be fixed to the base 41 . the ball joint 62 is also coupled with another edge 65 that can be fixed to the illuminator 2 . a lock dial 66 can be provided on one end of the rotatable axis 63 . the mounting arm 6 can be configured to lock any movements related to the joint balls 61 , 62 the rotatable axis 63 , and the parts of arm 67 , 68 when the lock dial 66 is tightened . in operation , apparatus 1 can be used as follows . the fingertip of a subject to be tested can be placed on a finger holder 9 as shown in fig3 . the illuminator is typically adjusted so that the fingertip on the holder 9 can be successfully exposed to the light ( for example , by use of rotations at the joint ball 61 , 62 and the axis 63 ). the illuminator can be fixed in a desired position by tightening of the lock dial 66 . when the lock dial 66 is tightened , the first knob 512 can be loosened so the supporting arm 5 can be used to move the optics processing and imaging component 3 to where the component 3 is placed above the fingertip on the holder . the fingertip on the holder 9 can be illuminated by turning on the light source 22 of the illuminator 2 , while focusing the light from the source 22 through an aperture mechanism in the opening 23 . a fan 24 can also be used to cool the illuminator 2 . the objective lens of the magnification ratio adjustor 32 can be brought to a desired location adjacent to the fingertip on the holder 9 by sliding the second stage 52 with respect to the first stage 51 along the z - axis direction by rotation of the second knob 513 or the third knob 514 , and / or sliding of the third stage 53 with respect to the second stage 52 along the x - axis direction by rotation of the forth knob 533 , and / or sliding of the forth stage 54 with respect to the third stage 53 along the y - axis direction by rotation of the fifth knob 534 . the magnification ratio ( such as when zooming is ) can be performed by using the magnification ratio adjustor 32 . an image of the enlarged capillary vessels can be seen as illustrated by fig1 . although the invention has been described herein by way of exemplary embodiments , variations in the structures and methods described herein may be made without departing from the spirit and scope of the invention . for example , the positioning and / or sizing of the various components may be varied . individual components and arrangements of components may be substituted as known to the art . since many embodiments of the invention can be made without departing from the spirit and scope of the invention , the invention is not limited except as by the appended claims .
blood flow in capillary vessels can be observed by using a magnification ratio that can be altered by the magnification ratio adjustor without causing blurring so that zooming operations can be easily performed . an objective lens can easily be centered relative to a fingertip , for example , without causing a burden to patients by having the patients themselves move their fingertips to bring a desired image into focus . heat dissipation from the illuminator can be facilitated , and the imaging units can be more compactly designed .