Apparatus and method for recognizing home position of rotatable body

Provided are an apparatus and method for recognizing a home position of a rotatable body. The apparatus includes: a tray including a support surface on which the rotatable body can be seated; a rotatable body position alignment unit for controlling the position of the rotatable body so that the rotatable body is aligned to be in a predetermined position when the rotatable body is seated on the support surface of the tray; a motor including a motor shaft that rotates by power supply, and a turntable that can be coupled with the rotatable body and rotates the rotatable body; and an encoder that is connected to the motor shaft and generates signals for measuring a rotational angle and a rotational direction of the motor shaft.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2009-0003406, filed on Jan. 15, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more embodiments relate to an apparatus and method for recognizing a home position of a rotatable body such as a disc-shaped microfluidic apparatus.

2. Description of the Related Art

In microfluidics, research into disc-shaped microfluidic apparatuses that are used to perform immunoserology and gene tests for a short time period is being conducted. Disc-shaped microfluidic apparatuses are referred to as a Lab Compact Disc (CD) or a Lab-on-a-CD, and transport a fluid by using a centrifugal force generated due to their rotary motion.

In order to perform biological sample reactions and detect reaction results in such a microfluidic apparatus, the positions of structures placed in microfluidic apparatus, such as valves, functional units, or chambers for sensing reactions, need to be precisely recognized. In the related art, a process of recognizing a home position, which is a reference position to identify the positions of structures, is performed and then, the positions of the structures are identified. The home position can be recognized by using a light source for irradiating light, a mark that is formed in the rotatable body and reflects light irradiated from the light source, and an optic sensor that senses the reflected light.

SUMMARY

One or more embodiments include an apparatus and method for recognizing a home position of a rotatable body, without a process or sensor for recognizing the home position of the rotatable body.

To achieve the above and/or other aspects, one or more embodiments may include an apparatus for recognizing a home position of a rotatable body, the apparatus including: the rotatable body; a tray including a support surface on which the rotatable body can be seated; a rotatable body position alignment unit for controlling the home position of the rotatable body in such a way that only when the rotatable body is aligned to be in a predetermined position, the rotatable body is seated on the support surface of the tray; a motor including a motor shaft that rotates by power supply and a turntable that can be coupled with the rotatable body and rotates the rotatable body; and an encoder that is connected to the motor shaft and generates signals for measuring a rotational angle and rotational direction of the motor shaft, wherein when the encoder outputs a Z-phase signal, the turntable is coupled with the rotatable body so that the rotatable body rotates, or the turntable is separated from the rotatable body so that rotary motion of the rotatable body stops and the rotatable body is seated on the support surface of the tray.

The rotatable body position alignment unit includes: a protrusion that is formed in the tray and protrudes toward the rotatable body; and a groove that is formed in the rotatable body and is recessed corresponding to the protrusion.

The apparatus may further include an elasticity application unit that elastically presses against the rotatable body to reduce a positioning error of the rotatable body and is formed in the protrusion or the turntable.

The rotatable body may have an engagement hole in a central portion of the rotatable body so that the turntable can be inserted into and coupled with the rotatable body, the support surface of the tray may have an opening through which the turntable is passable, and the turntable is lifted through the opening of the support surface of the tray and is coupled with the engagement hole of the rotatable body and is descended through the opening of the support surface of the tray and is separated from the engagement hole of the rotatable body.

The turntable may lift the rotatable body seated on the support surface of the tray so that the turntable is separated from the support surface of the tray, and after the rotatable body is seated on the support surface of the tray, the turntable is descended further from the rotatable body so that the turntable is separated from the rotatable body.

The rotatable body may be a microfluidic apparatus for performing a biochemical reaction using a small amount of a biological sample.

The tray may be slideable between a first position in which a lengthwise direction extension line of the motor shaft passes through a central portion of the rotatable body seated on the support surface of the tray and a second position in which the tray is located out of the lengthwise direction extension line of the motor shaft.

To achieve the above and/or other aspects, one or more embodiments may include a method of recognizing a home position of a rotatable body, the method including: mounting the rotatable body, the mounting including aligning the rotatable body to be in a predetermined position and seating the aligned rotatable body on a support surface of a tray; and coupling a turntable with the rotatable body when an encoder that is connected to a motor shaft for rotating the rotatable body outputs a Z-phase signal.

The method may further include: driving the rotatable body, the driving including separating the rotatable body from the support surface of the tray and rotating the turntable and the rotatable body coupled with the turntable; stopping the rotary motion of the rotatable body when the encoder outputs the Z-phase signal, so that the rotatable body is aligned to be in a predetermined position; and separating the turntable from the rotatable body, the separating including seating the rotatable body on the support surface of the tray and separating the turntable from the rotatable body.

DETAILED DESCRIPTION

Hereinafter, an apparatus and method for recognizing a home position of a rotatable body according to one or more embodiments will be described in detail with reference to the attached drawings.

FIG. 1is a perspective view of an apparatus for recognizing a home position of a rotatable body100according to an embodiment.

Referring toFIG. 1, the apparatus may include the rotatable body100. The rotatable body100may be a disc-shaped microfluidic apparatus. The apparatus may also include: a tray120A having a support surface122on which the rotatable body100can be seated; a motor140including a motor shaft155that rotates by power supply, and a turntable145that can be coupled with the rotatable body100and rotate the rotatable body100; and an encoder150that is connected to the motor shaft155and generates signals for measuring a rotational angle and a rotational direction of the motor shaft155.

The disc-shaped microfluidic apparatus is used to perform a biochemical reaction using a small amount of a biological sample. Although not illustrated inFIG. 1, the disc-shaped microfluidic apparatus may include chambers for accommodating a fluid, channels through which the fluid flows, valves for adjusting the fluid flow, or various functional units for performing a predetermined function using the fluid. The rotatable body100may have an engagement hole102in a central portion of the rotatable body100to allow the turntable145to be inserted into the rotatable body100. The turntable145has an alignment protrusion147that protrudes in a radial direction of the turntable145, and the engagement hole102of the rotatable body100has an alignment groove103corresponding to the alignment protrusion147. If the turntable145and the engagement hole102are aligned with one another and the turntable145is inserted into the engagement hole102in such a way that the alignment protrusion147is correspondingly inserted in the alignment groove103, when the turntable145rotates, the rotatable body100is synchronized with the turntable145and rotates together with the turntable145. In this case, idling rotation of the rotatable body100with respect to the turntable145is prevented.

The support surface122of the tray120A has an opening124through which the turntable145is passable. The turntable145can be upwardly inserted through the opening124of the support surface122and is coupled with the engagement hole102of the rotatable body100. Also, the turntable145can be downwardly lowered through the opening124and is separated from the engagement hole102of the rotatable body100.

The apparatus may further include a rotatable body position alignment unit that controls the position of the rotatable body100in such a way that only when the rotatable body100is aligned to be in a predetermined position, the rotatable body100is seated on the support surface122of the tray120A. The rotatable body position alignment unit may include a protrusion126that is formed in the tray120A and protrudes toward the rotatable body100so that the protrusion can correspond to a groove105that is formed in the rotatable body100and is recessed to correspond to the protrusion126. Due to the protrusion126, only when the groove105is positioned to correspondingly receive the protrusion126, the rotatable body100is seated on the support surface122.

The encoder150outputs A-phase, B-phase, and Z-phase signals as the motor shaft155rotates. The Z-phase signal is regularly generated once whenever the motor shaft155makes one complete rotation. In the rotatable body position alignment unit, when the rotatable body100is seated on the support surface122and the turntable145is aligned so as to be inserted into the engagement hole102of the rotatable body100, in other words, when the alignment groove103of the engagement hole102and the alignment protrusion147of the turntable145are aligned, the encoder150is initialized to output the Z-phase signal.

In a case in which the rotatable body100is seated on the support surface122, when the encoder150outputs the Z-phase signal while the turntable145fixed to the motor shaft155rotates, the turntable145stops. Then, the turntable145is upwardly inserted into the engagement hole102, thereby coupling with the rotatable body100(seeFIG. 2B.) Then, if the turntable145is lifted further, the rotatable body100is lifted together with the turntable145, and separates from the support surface122(seeFIG. 2C.) Then, the rotatable body100is rotated by rotating the turntable145. A position of the rotatable body100when the rotatable body100begins to rotate is maintained uniform due to the protrusion126, and the rotational angle may be precisely determined according to an output signal of the encoder150. Accordingly, despite the rotary motion of the rotatable body100, the location of chambers, channels, valves, or functional units, which are included in the rotatable body100, may be precisely identified.

To seat the rotatable body100back on the tray120A, when the encoder150outputs the Z-phase signal, the rotary motion is stopped. In this case, the protrusion126of the tray120A and the groove105of the rotatable body100are aligned. Then, the turntable145is descended so that the rotatable body100is seated on the support surface122. Then, the turntable145is descended further from the tray120A, thereby separating the turntable145from the rotatable body100.

FIGS. 2A through 2Care perspective views for sequentially explaining a method of recognizing a home position of a rotatable body by using an apparatus for recognizing the home position of the rotatable body, according to another embodiment. Hereinafter, the apparatus for recognizing a home position of a rotatable body and the method of recognizing a home position of the rotatable body will be described in detail with reference toFIGS. 2A through 2C. Like elements illustrated inFIGS. 1 and 2Athrough2C are denoted by like reference numerals. Accordingly, the method and apparatus for recognizing the home position of the rotatable body100of FIGS.2A through2C will now be described in terms of differences between the method and apparatus for recognizing the home position of the previous embodiment that is shown inFIG. 1and the method and apparatus for recognizing the home position that is shown inFIGS. 2A through 2C.

Referring toFIG. 2A, the apparatus for recognizing a home position of the rotatable body100may be included in a biochemical analyzer10. The biochemical analyzer10may provide outer conditions appropriate for a biological sample reaction that is measurable in the rotatable body100such as a microfluidic apparatus, and detects the results of the biological sample reaction that occurs in the microfluidic apparatus100. The apparatus includes the rotatable body100, a tray120B having the support surface122on which the rotatable body100can be seated, the motor140including the motor shaft155and the turntable145, and the encoder150that is connected to the motor shaft155. Since the rotatable body100, the motor140, and the encoder150have already been described with reference toFIG. 1, the rotatable body100, the motor140, and the encoder150will not be described in detail in this section.

The tray120B has the support surface122on which the rotatable body100can be seated, and the support surface122has the opening124through which the turntable145is passable. In the biochemical analyzer10, the tray120B is slideable between a first position (seeFIGS. 2B and 2C) in which a lengthwise direction extension line S of the motor shaft155passes through a central portion of the rotatable body100seated on the support surface122and a second position (seeFIG. 2A) in which the tray120B is located out of the lengthwise direction extension line S of the motor shaft155. The tray120B is moved from the first position to the second position through a slot (see15ofFIG. 2B) of the biochemical analyzer10.

The method of recognizing a home position of the rotatable body100by using the apparatus described above may include: mounting the rotatable body100, the mounting including aligning the rotatable body100to be in a predetermined position and seating the aligned rotatable body100on the support surface122of the tray120B; and coupling the turntable145with the rotatable body100when the encoder150outputs the Z-phase signal. In addition, the method of recognizing a home position of the rotatable body100may further include: driving the rotatable body100, the driving including separating the rotatable body100from the support surface122and rotating the turntable145and the rotatable body100coupled with the turntable145; stopping the rotary motion of the rotatable body100when the encoder150outputs the Z-phase signal, so that the rotatable body100is aligned to be in a predetermined position; and separating the turntable145from the rotatable body100, the separating including seating the rotatable body100on the support surface122and separating the turntable145from the rotatable body100.

Specifically, to mount the rotatable body100, the tray120B is moved to the second position, the groove105of the rotatable body100is aligned with the protrusion126of the tray120B, and the rotatable body100is descended onto the support surface122of the tray120B, thereby seating the rotatable body100on the support surface122of the tray120B.

Referring toFIG. 2B, the coupling of the turntable145with the rotatable body100may include moving the tray120B to the first position, rotating the turntable145of the motor140until the encoder150outputs the Z-phase signal, and when the Z-phase signal is generated, stopping the rotary motion of the turntable145and lifting the turntable145. The lifted turntable145is correspondingly inserted into the engagement hole102of the rotatable body100and coupled with the rotatable body100.

Referring toFIG. 2C, the driving of the rotatable body100may include separating the rotatable body100from the support surface122by further lifting the turntable145when the rotatable body100is seated on the support surface122, and, in this separation state, rotating the rotatable body100by rotating the turntable145. When the rotatable body100begins to rotate, the position of the rotatable body100is maintained uniform due to the protrusion126, and the rotational angle is precisely identified by referring to an output signal of the encoder150. Accordingly, despite the rotary motion of the rotatable body100, the location of chambers, channels, valves, or functional units, which are included in the rotatable body100, may be precisely identified.

The stopping of the rotary motion of the rotatable body100includes stopping the rotary motion of the turntable145when the encoder150outputs the Z-phase signal. When the rotary motion of the rotatable body100is stopped, the protrusion126of the tray120B and the groove105of the rotatable body100are aligned. The separating of the turntable145from the rotatable body100includes seating the rotatable body100on the support surface122by lowering the turntable145and separating the turntable145from the rotatable body100by lowering the turntable145further from the tray120B. Then, the tray120B is moved to the second position illustrated inFIG. 2Aand the rotatable body100is removed from the biochemical analyzer10.

FIG. 3is a plan view of the apparatus illustrated inFIG. 1orFIGS. 2A through 2C, wherein the rotatable body100is seated on the tray120A or120B and inserted into the turntable145, according to an embodiment.

Referring toFIG. 3, the apparatus may further include an elasticity application unit that elastically presses against the rotatable body100to reduce a positioning error of the rotatable body100. For example, the elasticity application unit may include a first ball plunger130that elastically presses against an inner surface of the groove105of the rotatable body100and is formed in the protrusion126of the tray120A or120B, or a second ball plunger148that elastically presses against an inner surface of the alignment groove103of the rotatable body100and is formed in the alignment protrusion147of the turntable145. To further reduce the positioning error of the rotatable body100, the inner surface of the groove105and the inner surface of the alignment groove103which are elastically pressed by the ball plungers130and148may be partly recessed to form grooves having an appropriate size to receive the ball plungers130and148.