A digital focusing device

Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention

[0001] This invention is related to a digital focusing device.

Background of the invention

[0002] Accurate focusing of sample placed under a microscope is very critical in medical fields for diagnosis, as the sample is viewable at higher magnifications, for example, 400X magnification. At such high magnification, even a small movement of the sample or the objective lens can cause distortion in the focused image. In the current microscopes, a stage moves up to achieve fine focusing. As the stage is bulky, the design of a positional controller for movement in three dimensions (i.e. X axis, Y axis and Z axis] becomes more complex due to usage of gears, rack and pinion mechanism, etc. which in turn leads the stage heavy. To achieve the focus, the positional controller powered by piezo motors are used, but this makes the entire setup expensive.

[0003] A prior art document US20100067104 discloses a a sample holder for a microscope.The sample holder comprises a sample chamber which is filled with an immersion liquid and in which a sample is located. The sample chamber has an upper opening. It further comprises means for translating the sample relative to a detection objective of the microscope, and means for rotating the sample around an axis of rotation extending in a substantially horizontal plane which encloses an angle other than zero degrees with the optical axis of the detection objective. In a sample holder of this kind, the sample is embedded in a transparent embedding medium having at least partially a greater solidity than the immersion liquid. Further, the sample chamber has means for horizontally supporting the embedded sample against the effect of gravity.

Brief description of the accompanying drawings

[0004] Figure 1 illustrates a digital focusing device, in accordance with an embodiment of the present invention;

[0005] Figure 2 illustrates a first plate of the digital focusing device, in accordance with an embodiment of the invention;

[0006] Figure 3 illustrates a first motor assembly of the digital focusing device, in accordance with an embodiment of the invention, and

[0007] Figure 4 illustrates the digital focusing device, in accordance with an embodiment of the invention.

Detailed description of the embodiments

[0007] Figure 1 illustrates a digital focusing device 10, in accordance with an embodiment of the present invention. The digital focusing device 10 comprises a sample holder 12 adapted to hold a sample 13. The device 10 characterized in that, further comprises a first plate 18 comprising a first guide rail assembly 14 and a second guide rail assembly 16. The device 10 comprises a second plate 20 slidably fitted on top of the first and second guide rail assemblies (14, 16). The device 10 comprises a third guide rail assembly 22 mounted on the second plate 20. The device 10 further comprises a first connecting block 26 movably fitted on the third guide rail assembly 22, and connected to the sample holder 12 .

[0008] Further the construction of the digital focusing device 10 and the components of the digital focusing device 10 is explained as follows. According to one embodiment of the invention, the first and the second guide rail assemblies (14, 16) are made identical to each other. The second plate 20 is positioned in perpendicular to the first plate 18 in a horizontal plane. The first plate 18 comprises a first cavity (28(a)) and a second cavity 28(b)) (Refer fig. 2) to accommodate the first and the second guide rail assemblies (14, 16). The first plate 18 further comprises a third cavity 30 (Refer Fig. 2) made at the center of the plate 18 to allow light from the light source 32 to illuminate the content of the sample 13. The light source 32 is placed under the first plate 18 at the center portion where the third cavity 30 is made. The first and the second guide rails assemblies (14, 16] are fitted on the cavities (28(a], 28(b]] of the first plate 18 using at least one of the fitting techniques that is known to a person skilled in the art. One such fitting technique used in this disclosure is a screw fitting technique. However, it is not restricted to the above-disclosed fitting technique.

[0009] Figure 2 illustrates a first plate of the digital focusing device, in accordance with an embodiment of the invention. The first plate 18 is made in the form of any polygonal shape comprising a rectangle, a square and the like. The dimensions of the first plate 18 is different from the second plate 20. The second plate 20 is made smaller in dimensions than the first plate 18. According to one embodiment of the invention, the position of the first and the second plates (18, 20] when placed above each other takes the shape of a cross symbol. The second plate 20 further comprises a vertical extension 24 made on a side of the second plate 20. The vertical extension 24 is made perpendicular to the second plate 20 in the vertical plane.

[0010] The third guide rail assembly 22 is mounted on the vertical extension 24, such that, the sample holder 12 is made to move on the third rail guide 46 along the length of the vertical extension 24 of the second plate 20. One end of the first connecting block 26 is fixed on the guide of the third guide assembly 22 and another end is fixed on a portion of the second plate 20. The first connecting block 26 connects the sample holder 12 to the second plate 20.

[0011] Figure 3 illustrates a first motor assembly of the digital focusing device, in accordance with an embodiment of the invention. The device 10 comprises a first motor assembly 34, a second motor assembly 38 and a third motor assembly 46. The first motor assembly 34 is mounted on one end of the second plate 20 in proximity to the first guide rail assembly 14. The first motor assembly 34 comprises a spindle 36. The first connecting block 26 is coupled to the spindle 36 and is connected to the sample holder 12. The second motor assembly 38 is fitted to a bottom surface of the first plate 18. The second motor assembly 38 comprises a spindle 40. According to one embodiment of the invention, the position of the second motor assembly 38 is perpendicular to the first motor assembly 34 (fitted on the top surface of the second plate 20] in a horizontal plane.

[0012] Figure 4 illustrates the digital focusing device, in accordance with an embodiment of an invention. The second motor assembly 38 is firmly fixed (made stationary] to the bottom surface of the first plate 18 , wherein , the first motor assembly 34 is made movable on the first and second guide rail assemblies (14,16] along with the second plate 18 and the first connecting block 26.. The device 10 further comprises a second connecting block 42 that is coupled to the second motor assembly 38 through the spindle 40, and connected to the second plate 20. A rotational movement of the spindle 40 of the second motor assembly 38 moves the second connecting block 42, which in turn moves the second plate 20 and the sample holder 12in y-axis direction.

[0013] The third motor assembly 46 is placed in a housing 44 of the device 10 and is coupled to a movable objective holder 48 positioned above the sample holder 12. The third motor 46(a] is adapted to adjust a position of the objective holder 48 above the sample holder 12. The device 10 comprises a control unit 54 electronically connected to the first, second and third motor assemblies (34, 38, 46] The control unit 54 is adapted to adjust the objective holder 48 and the sample holder 12 via the respective spindles (36, 40] and connecting blocks (26, 42] The first, second and the third motors (34(a], 38(a], 46(a]] of the respective motor assemblies (34, 38, 46] are chosen from a group of motors comprising a linear motor, a stepper motor and the like. However, the first, the second and the third motor (34(a], 38(a], 46(a]] types are not restricted to a linear motor or a stepper motor, but can be any motor chosen from a group of motor comprising a piezo-electric motor, a hydraulic motor and the like.

[0014] The objective holder 48 comprises a lens 56 adapted to focus on the sample 13 when focused. The housing 44 of the device 10 further comprises a camera (not shown] placed in a focal holder, such that, the lens 56 of the objective holder 48, the camera, the sample holder 12 and the light source 32 of the device 10 are positioned in a straight line (arranged one above the other in a predetermined pattern and distance]. The objective holder 48 is moved/adjusted in a tangential /perpendicular (such as z-axis] direction with respect to the sample 13 during focusing on at least one portion of the sample 13. The objective holder 48 is connected to the third motor 46(a] mechanically via an inverted L-shaped plate 50 and a fourth guide rail assembly 52.

[0015] The sample 13 in the sample holder 12 is placed in a planar position. The content of the sample 13 is chosen from a group of contents comprising a blood sample, a urine sample, a semen sample or the like. The content of the sample 13 is smeared on the surface of the sample 13, before placing it in the sample holder 12. According to one embodiment of the invention, the sample holder 12 is maintained in a fixed portion, when the objective holder 48 is adjusted for focusing of the sample 13. In another embodiment of the invention, the sampled holder 12 is moved, when objective holder 48 is maintained in a fixed portion for focusing on the sample 13.

[0016] A method of working of the above-disclosed device 10 is explained as follows. In order to view and analyze the content in the sample 13, the sample 13 that is placed in the sample holder 12 is moved in any one of the directions comprising axial direction, radial direction and a tangential direction. The first motor assembly 34 is adapted to move the sample holder 12 in the axial direction (i.e., x-axis direction] and the second motor assembly 38 is adapted to move the sample holder 12 in the radial direction (i.e., y-axis direction]. The third motor assembly 46 is adapted to move the movable objective holder 48 to move in the tangential direction (z-axis direction], such that, the content of the sample 13 is efficiently analyzed.

[0017] When the control unit 54 operates the first motor 34(a] of the first motor assembly 34, the spindle 36 of the first motor assembly 34 is rotated. The rotatory movement of the spindle 36 moves the sample holder 12 in the axial direction. The first connecting block 26 moves the sample holder 12 from one end of the first plate 18 to another end in the horizontal plane. Since the first connecting block 26 is mounted on the third guide rail assembly 22, the movement of the sample holder 12 along with the first connecting block 26 is made smooth. The first connecting block 26 and the sample holder 12 moves in coordination with the third guide on the third rail.

[0018] When the second motor 38 (a] is operated by the control unit 54, the spindle 40 rotates. Due to the rotational movement of the spindle 40, the second connecting block 42 moves the second plate 20, along with and the first motor assembly 34 which is fixed on the second plate 20 and the first connecting block 26 that is connected to the sample holder 12. The entire setup (the second plate 20 and the first motor assembly 34 and the first connecting block 26 along with the sample holder 12] moves on the first and the second guide rail assemblies (14, 16], due to the movement of the spindle 40 of the second motor assembly 38. Due to a roller based ball-screw mechanism used in the first and the second guide rail assemblies (14, 16], the above disclosed setup moves in the y- axis direction. Since, only the first motor assembly 34 is movable, the second motor 38 (a] is operated in such a way that, the above disclosed setup is moved to adjust the sample holder 12 in the y-axis direction.

[0019] When the control unit 54 operates the third motor 46(a], the third motor 46(a] moves the movable objective holder 48 via the inverted L-shaped plate 50 and the fourth guide rail assembly 52. The lens 56 of the objective holder 48 is properly focused on the content of the sample 13 in the sample holder 12 for an efficient analysis. The light is allowed to pass through the third cavity 30 of the first plate 18 to illuminate the content of the sample 13. The light source 32, the lens 56 and the sample holder 12 are positioned co-axial to each other.

[0020] With the above-disclosed digital focusing device 10, less number of components of the device 10 are in motion during the operating mode, when compared to the conventional structures, thus providing more accurate analysis on the content of the sample 13. The replacement or repair of the components that are connected to the first plate 18 can be done without much hassle. The dimensions of the first plate 18 and the other components are made as per the user requirement by maintaining the co-axial factor between the movable objective holder 48, the sample holder 12 and the light source 32. The above-disclosed device 10 works efficiently in the inclined positions, as there are less components that require movement during the operation of the device 10. The device 10 allows for scalability, when there is demand for increased movement in all three axes. Assembly and disassembly of the components connected to the first plate 18 allows for ease of serviceability due to the above-disclosed arrangement The automatic adjustment of the objective holder 48 on the sample 13 provides a cost- effective, less strain solution for the people working in the medical labs, as it reduces the human intervention to focus on the sample 13 manually.

[0021] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims