Rack with movable shielding component, and auto-sampler having the rack

A rack is provided wherein the type of micro-plate that is placed on the rack can be determined even when using one type of rack. The rack includes a bottom piece on which micro-plate is placed; at least one shielding component for recognizing the type of micro-plate; and a recognition unit having an enclosure disposed with a shielding component. When the rack is housed in a housing unit of an analyzer main unit, the shielding component is movable with respect to the enclosure so that the shielding component is positioned either in a detection position where detectable by a sensor or in a non-detection position where undetectable by the sensor.

TECHNICAL FIELD

The present invention relates to a rack on which micro-plates are placed and an auto-sampler having the rack. The rack can be used, for example, in auto-samplers that are used in liquid chromatographic analyzers.

BACKGROUND

Liquid chromatographic analyzers are used for analyzing liquid specimens. A liquid chromatographic analyzer uses a needle to collect liquid specimens, which are injected into an analysis flowpath. When doing this, the liquid specimen is contained in a test tube (container) that is made of transparent glass or plastic.

Liquid chromatographic analyzers are sometimes used to analyze many liquid specimens. This has led to liquid chromatographic analyzers that are equipped with auto-samplers (e.g., see Patent Literature 1).FIG. 5shows a perspective view of a portion of a liquid chromatographic analyzer.FIG. 6shows a perspective view of a portion of an auto-sampler.FIG. 7shows a perspective view of a rack on which two micro-plates are placed.

The auto-sampler101includes: a control unit160and housing unit170, which houses rack120, both of which are disposed in the liquid chromatographic analyzer main unit150; a plurality of types (e.g., 7 types) of micro-plates10for holding a plurality of test tubes; and a plurality of types (e.g., 7 types) of racks120on which micro-plates10are placed.

A first micro-plate10is a case made of plastic. The first micro-plate10has a substantially rectangular parallelepiped shape with, for example, a width (X) of 85 mm, length (Y) of 125 mm and height (Z) of 25 mm. A first hole11through a 45thhole11are formed on the upper surface with five holes arranged in the X-direction (row direction) and nine holes arranged in the Y-direction (column direction). Each hole11is cylindrically-shaped which allows the lower half of a test tube to be inserted into a hole11. The result is that 45 test tubes are held in the first micro-plate10arranged as described in the X-direction and the Y-direction.

Furthermore, a second micro-plate (not illustrated) is a case made of plastic. The second micro-plate has a substantially rectangular parallelepiped shape with, for example, a width (X) of 85 mm, length (Y) of 125 mm and height (Z) of 25 mm. A first hole through a 32ndhole are formed on the upper surface with four holes arranged in the X-direction (row direction) and eight holes arranged in the Y-direction (column direction). Each hole is cylindrically-shaped which allows the lower half of a test tube to be inserted into a hole. The result is that 32 test tubes are held in the second micro-plate arranged as described in the X-direction and the Y-direction. In other words, different types of micro-plates are available, featuring different number of holes and different hole locations. The description of the third through the seventh micro-plate is omitted here.

The first rack120includes: a bottom piece121having, for example, a width (X) of 94 mm, length (Y) of 260 mm and height (Z) of 20 mm; a recognition unit122that is disposed at the front end (positive Y-direction end) of the bottom piece121; and a grip part123that is formed at the rear end (negative Y-direction end) of the bottom piece121. Two of the first micro-plates10can be placed in the Y-direction (column direction) on the upper surface of the bottom piece121.

The first rack120is provided with a recognition unit122which allows the control unit160of the liquid chromatographic analyzer main unit150to automatically recognize the type of micro-plate10that is housed in the housing unit170. The recognition unit122includes: an enclosure124that is made of resin and having a rectangular parallelepiped shape; and a first light-shielding plate125that is made of resin and protruding 4 mm out in the Y-direction from the enclosure124.

The second rack (not illustrated) includes: a bottom piece having, for example, a width (X) of 94 mm, length (Y) of 260 mm and height (Z) of 20 mm; a recognition unit that is disposed at the front end (positive Y-direction end) of the bottom piece; and a grip part that is formed at the rear end (negative Y-direction end) of the bottom piece. Two of the second micro-plates can be placed in the Y-direction (column direction) on the upper surface of the bottom piece. A recognition unit includes: an enclosure that is made of resin and having a rectangular parallelepiped shape; and a first light-shielding plate and a second light-shielding plate both made of resin and protruding 4 mm out in the Y-direction and being aligned in the X-direction. In other words, the first rack120and the second rack have different number of light-shielding plates125, and each micro-plate10has its own dedicated rack.

The housing unit170is provided with a plurality (e.g., three) of photosensors71at positions corresponding to the recognition unit122of the rack120. Beach photosensor71includes: an emission unit71athat emits light in the Z-direction; and a detection unit71bwhich detects light from the emission unit71awith a predetermined distance (e.g., 20 mm) of separation between them. Furthermore, a first photosensor71, a second photosensor71and a third photosensor71are formed to be aligned with each other in the X-direction. In this way, if three photosensors71are provided, there are eight possible combinations in which photosensors71may be shielded or not shielded from light. Since it is desirable for the housing unit170to be able to automatically recognize the absence of rack120, it is possible for the housing unit170to discriminate among 7 types of micro-plates10, excluding the situation where none of the photosensors71is shielded from light.

The control unit160determines the type of micro-plate10that is housed in the housing unit170based on the status of the recognition information (light-shielding information) that is detected by the three photosensors71.

For example, if the first rack120is housed in the housing unit170, since the first rack120has the first light-shielding plate125, the first photosensor71is shielded from light while the second photosensor71and the third photosensor71are not shielded from light. From this combination, it is determined that a first micro-plate10is housed in the housing unit170. If a second rack is housed in the housing unit170, since the second rack has both the first light-shielding plate and the second light-shielding plate, the first photosensor71and the second photosensor71are shielded from light while the third photosensor71is not shielded from light. From this combination, it is determined that a second micro-plate is housed in the housing unit170.

PATENT LITERATURE

Patent Literature 1: Unexamined Patent Application Publication H06-034614.

SUMMARY OF THE INVENTION

However, with the afore-described rack120, as many number of racks120is required as the number of different types of micro-plates10. Even though it is possible to use one replaceable rack and to swap and replace different recognition units from among a plurality of types of available recognition units, even then, as many recognition units as the number of types of micro-plates10would be necessary.

Hence, it is the object of the present invention to provide a rack wherein one type of rack can accept and recognize a plurality of different types of micro-plates.

To solve the afore-described problems, the rack according to the present invention to be housed in a housing unit of an analyzer main unit comprises:

a bottom piece on which micro-plates are placed;

at least one shielding component for recognizing the type of micro-plate; and

a recognition unit having an enclosure on which the shielding component is installed;

when the rack is housed in the housing unit of the analyzer main unit, the shielding component is movable with respect to the enclosure so that the shielding component is positioned at either a detection position detectable by a sensor that is installed on the housing unit of the analyzer main unit or a non-detection position undetectable by the sensor.

With a rack according to the present invention, when, for example, a person performing the analysis places a first micro-plate on the rack, a first shielding component is moved to the detection position. The rack is then placed in the housing unit of the analyzer main unit. This causes the first sensor, but not the second sensor, to detect the shielding component, resulting in the analyzer main unit to recognize what is housed as a first micro-plate. If the person performing the analysis places a second micro-plate on the rack, the first shielding component and the second shielding component are moved to the detection positions. The rack is then placed in the housing unit of the analyzer main unit. This causes the first sensor and the second sensor to detect the shielding components and the analyzer main unit to recognize that the second micro-plate is housed. Furthermore, if the person performing the analysis places a third micro-plate on the rack, the second shielding component is moved to the detection position. The rack is then placed in the housing unit of the analyzer main unit. This causes the second sensor, but not the first sensor, to detect the shielding component, resulting in the analyzer main unit to recognize the presence of a third micro-plate.

As afore-described, with a rack according to the present invention, any one of a plurality of different types of micro-plates that is placed on a rack can be recognized while using only one type of rack.

With the rack according to the present invention, the sensors may comprise an emission unit for emitting light and a detection unit for detecting, from a predetermined distance away, the light from the emission unit. The shielding component may be positioned at either a detection position or a non-detection position situated between the emission unit and the detection unit.

Here, the term “predetermined distance” refers to any distance that allows the insertion of the shielding component.

Furthermore, with the rack according to the present invention, the analyzer main unit is provided with a plurality of sensors, and the enclosure for the recognition unit is provided with a plurality of shielding components. Each of the shielding components are made to be independently movable with respect to the enclosure.

Furthermore, with the rack according to the present invention, formed on an upper surface of the enclosure of the recognition unit are movement grooves comprising a front-end portion and a rear-end portion having an increased width in plan view and a coupling part having a narrow width and coupling the front-end portion and the rear-end portion; and formed on the shielding component is a vertically extending protruding part whose top portion has a width narrower than the width of its bottom portion; the top portion of the protruding part passing through the movement groove in the horizontal direction while penetrating vertically through the coupling part of the movement groove; the bottom portion of the protruding part passing through the movement groove in the horizontal direction while penetrating vertically through the coupling part of the movement groove; and the shielding component being movable with respect to the enclosure when the protruding part is pressed downwardly.

The auto-sampler according to the present invention includes: a rack as afore-described; a plurality of types of micro-plates for holding a plurality of containers; and control unit and a housing unit for housing the racks, both of which are disposed on the analyzer main unit; wherein sensors are disposed on the housing unit, and the control unit determines the type of micro-plate based on recognition information from the sensors.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described next with reference to figures. It should be noted that the present invention is not limited to the embodiments described below, and needless to say, various modifications are possible without deviating from the gist of the present invention.

FIG. 1shows a perspective view of a part of a liquid chromatographic analyzer according to the present invention.FIG. 2shows a perspective view of a part of a rack according to the present invention. The same numerical references are used for the same components that appear in the description above of the auto-sampler101.

The auto-sampler1includes: a control unit60and a housing unit70in which racks20are housed, both units being provided in the liquid chromatographic analyzer main unit50; a plurality of types (e.g., 7 types) of micro-plates10for holding a plurality of test tubes; and one type of rack20on which a plurality of types (e.g., 7 types) of micro-plates10is placed.

The rack20includes: a bottom piece21having, for example, width (X) of 94 mm, length (Y) of 260 mm and height (Z) of 20 mm; a recognition unit22that is disposed at the front end (positive Y-direction end) of the bottom piece21; and a grip part23that is formed at the rear end (negative Y-direction end) of the bottom piece21. Two micro-plates10of different types are placed next to each other in the Y-direction (column direction) on the upper surface of the bottom piece21.

FIG. 3shows a perspective view of the recognition unit22that is shown inFIG. 2.FIG. 4shows an exploded perspective view of the recognition unit22shown inFIG. 3. The recognition unit22includes: a resin-made enclosure24in the shape of a quadrangular cylinder lying on its side with the central axis about the Y-direction; and four resin-made light-shielding components25that are installed on the interior of the enclosure24.

Formed on the upper surface of enclosure24are four movement grooves26that penetrate through the upper surface of enclosure24. In plan view, each movement groove26is shaped like the letter “I” with a quadrangular front-end portion26awith a broad width (X), a quadrangular rear-end portion26bwith a broad width (X) and a rectangular coupling part26chaving a narrow width (X) and joining the front-end portion26aand the rear-end portion26bin the Y-direction. The first movement groove26, second movement groove26, third movement groove26and fourth movement groove26are successively lined up in the X-direction. Furthermore, formed on the top portion of the lower surface of the enclosure24at positions corresponding to the movement grooves26are four rails (not illustrated) extending in the Y-direction.

The light-shielding component25includes: a black rectangular parallelepiped-shaped light-shielding part25a; a leaf spring part25bextending from the top of the light-shielding part25ain the negative Y-direction; and a protruding part25cthat extends from the tip of the leaf spring part25bin the Z-direction (upwardly). With the protruding part25c, the width (X) of the top portion (located higher than height h1) is narrower than the width (X) of the bottom portion (located lower than height h1). This arrangement means that the top portion of the protruding part25cpenetrates through the coupling part26cof the movement groove26in the Z-direction while passing through the coupling part26cof the movement groove26in the Y-direction, and the bottom portion of the protruding part25cpenetrates through the coupling part26cof the movement groove26in the Z-direction while passing through the coupling part26cof the movement groove26in the Y-direction. This means that when the light-shielding component25is attached to the movement groove26and the person performing the analysis presses in the protruding part25cby distance h1, the light-shielding component25moves in the Y-direction relative to the enclosure24. On the other hand, if the protruding part25cis not pushed in and either the front-end portion26aor the rear-end portion26bis penetrated through, the light-shielding component25becomes fixed to the enclosure24. At this time, if the protruding part25cis located at the position of the front-end portion26a, the light-shielding component25protrudes from the enclosure24by 4 mm in the Y-direction in a protruded state (detection position). On the other hand, if the protruding part25cis located at the position of the rear-end portion26b, the light-shielding component25remains contained (no-detection position) within the enclosure24.

After that, the first light-shielding component25is installed in the first movement groove26, the second light-shielding component25is installed in the second movement groove26, the third light-shielding component25is installed in the third movement groove26, and the fourth light-shielding component25is installed in the fourth movement groove26. This results in rack20to be housed in the housing unit70of the liquid chromatographic analyzer main unit50. If the first light-shielding component25is in the protruded state, first light-shielding component25becomes interposed between the emission unit71aof the first photosensor71and the detection unit71b(seeFIG. 6). On the other hand, if the first light-shielding component25remains contained within the enclosure, the first light-shielding component25is not interposed between the emission unit71of the first photosensor71and the detection unit71b. Also, if the second light-shielding component25is in the protruded state, the second light-shielding component25becomes interposed between the emission unit71aof the second photosensor71and the detection unit71b. On the other hand, if the second light-shielding component25is contained within the enclosure, the second light-shielding component25is not interposed between the emission unit71aof the second photosensor71and the detection unit71b. The third light-shielding component25and the fourth light-shielding component25are positioned similarly as the first light-shielding component25with respect to the third photosensor71and the fourth photosensor71, respectively.

On the housing unit70, a plurality (e.g., 4) of photosensors71is disposed at positions corresponding to the recognition unit22of the rack20. Each photosensor71includes: an emission unit71athat emits light in the Z-direction; and a detection unit71bthat detects light from the emission unit71awith a predetermined distance (e.g., 20 mm) of separation. First photosensor71, second photosensor71, third photosensor71and fourth photosensor71are formed to be successively lined up in the X-direction. By disposing the four photosensors71as afore-described, there are 16 different ways in which light from photosensors71can be shielded or not shielded. Incidentally, since it is desirable for the absence of a rack20in the housing unit70to be automatically recognized, a total of 15 types of micro-plates10can be recognized, not including the situation where none of the photosensors71is shielded from the light.

The control unit60uses the recognition information (light-shielding information) detected by the four photosensors71to determine the type of micro-plate10that is housed in the housing unit70.

For example, when the person performing the analysis places a first micro-plate10on rack20, the first light-shielding component25is moved to create a protruded state (detection position), and the second through the fourth light-shielding components25are moved to the contained state (no-detection position). Rack20is then placed in the housing unit70of the liquid chromatographic analyzer main unit50. This causes the first photosensor71to detect the presence of the light-shielding component, and the second through the fourth photosensors71to not detect the presence of a light-shielding component25. As a result, the control unit60recognizes that a first micro-plate10is housed within the enclosure.

Also, when the person performing the analysis places a second micro-plate on the rack20, the first light-shielding component25and the second light-shielding component25are moved to the protruded state (detection position), and the third through the fourth light-shielding components25are moved to the contained state (non-detection position). The rack20is then placed in the housing unit70of the liquid chromatographic analyzer main unit50. This causes the first photosensor71and the second photosensor71to detect the presence of the light-shielding components25, and the third through the fourth photosensors71to not detect the light-shielding component25. The result is for the control unit60to recognize the micro-plate as a second micro-plate.

In this way, the person performing the analysis places a micro-plate10of a certain type on the rack20and moves the light-shielding components25that correspond to that certain type of micro-plate11to the protruded state (detection position). The control unit60then determines the type of micro-plate10that is housed in the housing unit70. Information regarding the positioning of the light-shielding components25and the corresponding type of micro-plate10is stored in advance in the control unit60.

As afore-described, one type of rack20can accommodate a variety of types of micro-plates10and still recognize particular types of micro-plate10.

Other Embodiments

The afore-described auto-sampler1was equipped with photosensors71but other devices such as microswitches and magnetic sensors may be used instead.

The present invention can be used with racks and the like that are used with auto-samplers that are used with liquid chromatographic analyzers.

DESCRIPTION OF THE NUMERICAL REFERENCES