AUTOMATED ANALYSIS DEVICE

The present disclosure proposes, in order to increase a liquid temperature in a reaction tank to a predetermined temperature in a short time without increasing a capacity of a heater, an automatic analyzer including: the reaction tank configured to hold a liquid in which a reaction vessel configured to contain a reaction liquid is to be immersed; a pump configured to circulate the liquid and supply the liquid to the reaction tank; the heater configured to heat the liquid; a Peltier element configured to heat and cool the liquid; a first temperature sensor configured to detect a temperature of the liquid; and a control device configured to control an output of the heater and an output of the Peltier element based on the temperature detected by the first temperature sensor.

TECHNICAL FIELD

The present disclosure relates to an automatic analyzer.

BACKGROUND ART

In an automatic analyzer that analyzes a target component by mixing a sample and a reagent in a reaction vessel and measuring optical characteristics of a reaction liquid, it is necessary to accurately control a temperature of a liquid in which the reaction vessel is immersed in order to maintain measurement accuracy.

PTL 1 discloses an automatic analyzer having a configuration in which “a reaction vessel 2 attached on a circumference of a circular reaction disc 1 is immersed into a liquid held by a circular reaction tank 3. The liquid in the reaction tank is constantly circulated by a circulation pump 6 disposed between a discharge pipe 4 and a supply pipe 5. A temperature of the liquid is controlled through ON/OFF control by a heater 7 to maintain a reaction liquid held in the reaction vessel 2 at an optimal temperature for reaction (for example, 37° C.). The liquid in the reaction tank may be water or any other solution. A cooling unit 8 may be provided for cooling the liquid if the liquid temperature in the reaction tank rises too much.” (see paragraph 0015 in PTL 1)

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Since the cooling unit disclosed in PTL 1 has only a cooling function, when an ambient temperature is low in winter or the like, it takes a long time until a liquid temperature of the reaction tank reaches a predetermined temperature. In order to quickly increase the liquid temperature, it is necessary to increase a capacity of the heater.

Therefore, the present disclosure provides a technique for increasing a liquid temperature of a reaction tank to a predetermined temperature in a short time without increasing a capacity of a heater.

Solution to Problem

In order to solve the above problems, an automatic analyzer in the present disclosure includes: a reaction tank configured to hold a liquid in which a reaction vessel configured to contain a reaction liquid is to be immersed; a pump configured to circulate the liquid and supply the liquid to the reaction tank; a heater configured to heat the liquid; a Peltier element configured to heat and cool the liquid; a first temperature sensor configured to detect a temperature of the liquid; and a control device configured to control an output of the heater and an output of the Peltier element based on the temperature detected by the first temperature sensor.

Additional features related to the present disclosure will be clarified based on the description of the present description and the accompanying drawings. Aspects of the present disclosure may be achieved and implemented using elements, combinations of various elements, the following detailed description, and accompanying claims. The description of the present description is merely a typical example, and does not limit the scope of the claims or application examples of the present disclosure in any sense.

Advantageous Effects of Invention

According to the technique of the present disclosure, a liquid temperature of the reaction tank can be increased to a predetermined temperature in a short time without increasing a capacity of the heater. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

DESCRIPTION OF EMBODIMENTS

First Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.1is a schematic diagram showing a configuration in the vicinity of a reaction tank1in an automatic analyzer according to a first embodiment. The automatic analyzer includes the reaction tank1, a pump3, a Peltier unit5, a heater6, a temperature sensor7, a control device8, a light source10, a photometer11, a disc12, and a tube13.

FIG.1shows a vertical cross-sectional view of the reaction tank1. The reaction tank1has a substantially circular shape in a top view. A thermostatic water tank14is provided inside the reaction tank1. The reaction tank1is of a water circulation type in which circulating water circulates inside the thermostatic water tank14.

The disc12has a substantially circular shape in the top view, and is configured to hold a plurality of reaction vessels2. The reaction vessel2contains a reaction liquid in which a biological sample such as blood or urine and a reagent are mixed. The reaction vessel2is immersed in the thermostatic water tank14.

The pump3circulates the circulating water to the reaction tank1. The circulating water discharged from the reaction tank1is cooled or heated in the Peltier unit5, heated in the heater6, reaches the reaction tank1, and returns from the reaction tank1to the pump3. The tube13connects the above components through which the circulating water flows. The temperature sensor7is disposed downstream of the heater6, detects a temperature of the circulating water introduced into the reaction tank1, and outputs a detection signal of the temperature to the control device8.

The control device8is a computer device such as a general-purpose computer, a smartphone, or a tablet terminal. Although not illustrated, the control device8includes a processor that executes processing described in the present description, a memory that temporarily stores a program executed by the processor and other necessary data, a storage device that stores the program, and an input and output device.

The control device8controls an input to the Peltier unit5and an input to the heater6such that a temperature detected by the temperature sensor7becomes a target temperature. Thus, in the present embodiment, the heater6is disposed downstream of the Peltier unit5, and a temperature of circulating water passing through the heater6is detected by the temperature sensor7. Such a configuration is advantageous when the temperature of the circulating water supplied to the reaction tank1is adjusted mainly by the heater6.

The Peltier unit5includes a Peltier element4, a liquid jacket9, fins51, and a fan52. A detailed configuration of the Peltier unit5will be described later.

The light source10is disposed inside the reaction tank1and irradiates the reaction vessel2with light. The photometer11measures absorbance of light passing through the reaction vessel, and outputs a measurement signal to the control device8or another arithmetic device. The control device8or the other arithmetic device performs a qualitative and quantitative analysis on a specific component in the biological sample based on the measurement signal received from the photometer11. Since a temperature of the reaction liquid affects analysis accuracy, it is necessary to control a water temperature in the thermostatic water tank14in which the reaction vessel2is immersed to a constant temperature.

<Configuration Example of Peltier Unit>

FIG.2is a cross-sectional view of the Peltier unit5. As shown inFIG.2, the Peltier unit5includes the Peltier element4, thermal interfaces201to203such as grease, a heat spreader204, a case205made of, for example, a resin, the fins51, a fin base206, the fan52, and a tube connector211. The tube connector211connects the tube13(not shown inFIG.2) and a flow path214in the liquid jacket9.

When the circulating water is cooled, the Peltier element4is energized so that a temperature of a surface of the Peltier element4on a side of the liquid jacket9is low, and a temperature on a side of the fin base206is high. Heat of the circulating water flowing through the flow path214of the liquid jacket9is absorbed by the Peltier element4from the liquid jacket9via the thermal interface201and the heat spreader204, so that the circulating water is cooled. On the other hand, an opposite side of the Peltier element4generates heat, and the heat is transferred from the fin base206to the fins51via the thermal interface203, and is radiated to air sent between the fins51by the fan52.

On the other hand, when the circulating water is heated, the Peltier element4is energized so that the temperature of the surface of the Peltier element4on the side of the liquid jacket9is high, and the temperature on the side of the fin base206is low. The surface of the Peltier element4on the side of the liquid jacket9generates heat, the heat is transferred to the liquid jacket9, and the circulating water flowing through the flow path214is heated. The opposite side of the Peltier element4becomes a heat absorbing surface, and absorbs heat from the air flowing between the fins51through the fins51and the fin base206. In the following description, an operation in which the Peltier element4cools the circulating water is referred to as a cooling operation, and an operation in which the Peltier element4heats the circulating water is referred to as a heating operation.

The liquid jacket9, the heat spreader204, the fins51, and the fin base206can be made of metal such as stainless steel or aluminum. The case205can be formed of a heat insulating material such as a resin having heat insulating properties, which can further prevent heat conduction between the liquid jacket9and the fins51, allowing for efficient cooling and heating of the circulating water in the liquid jacket9.

FIG.3is a cross-sectional view showing a configuration example of the liquid jacket9.FIG.3shows a cross section in a direction orthogonal to a cross section inFIG.2. As shown inFIG.3, the flow path214in the liquid jacket9can be divided into a plurality of flow paths by a plurality of fins213. The circulating water supplied from the tube connector211to the liquid jacket9flows through the flow path214between the fins213to absorb or radiate heat, and is discharged from a tube connector212.

FIG.4is a cross-sectional view showing another configuration example of the liquid jacket9. In the example inFIG.4, a meandering flow path215is provided instead of the flow path214. The circulating water supplied from the tube connector211to the liquid jacket absorbs or radiates heat while flowing through the meandering flow path215, and is discharged from the tube connector212.

<Configuration Example of Heater>

FIG.5is a cross-sectional view showing a configuration example of the heater6. The heater6includes a sheath heater301serving as a heating unit, a water channel wall302, a heat insulating material303, a flow path304, a tube connector305, a tube connector306, and a power cord307.

The water channel wall302has a substantially cylindrical shape, and the linear sheath heater301is disposed in an internal space of the water channel wall302, and the flow path304is defined. A joint between the sheath heater301and the water channel wall302is sealed to prevent the circulating water from leaking to an outside. The water channel wall302is covered with the heat insulating material303. The power cord307connects the sheath heater301and power supply, and energization of the sheath heater301by the power supply is controlled by the control device8. The sheath heater301is heated by being energized. The circulating water is supplied from the inlet tube connector305, and is heated by the sheath heater301while passing through the flow path304and flowing to the outlet tube connector306. A heating amount of the sheath heater301is controlled by adjusting an input from the power supply. A type of the sheath heater301may be either DC power supply or AC power supply. Methods of changing an input to the sheath heater301include changing a voltage of the power supply, changing an energization rate (operation rate) by switching the power supply at a constant voltage, and using a thyristor in the case of an alternating current.

<Peltier Element and Operation Method of Heater>

Next, an operation pattern of the Peltier element4of the Peltier unit5and the heater6in the present embodiment will be described in comparison with an example in the related art.

FIG.6Ais a diagram showing an operation pattern of a cooling unit (refrigerator) and a heater in an example in the related art (PTL 1). As shown inFIG.6A, in the example in the related art, since the cooling unit can only perform a cooling operation, the cooling operation is always performed regardless of a water temperature of the circulating water. On the other hand, the heater is always in heating operation, but a heating amount applied to the circulating water is controlled by changing an input to the heater.

FIG.6Bis a diagram showing an operation pattern of the Peltier element4and the heater6in the present embodiment. In the present embodiment, when the water temperature detected by the temperature sensor7is lower than a predetermined operation switching temperature Tc, the control device8controls the Peltier element4to perform a heating operation of heating the surface on the side of the liquid jacket9, and when the water temperature is equal to or higher than the operation switching temperature Tc, the control device8controls the Peltier element4to perform a cooling operation of cooling the surface on the side of the liquid jacket9. The operation switching temperature Tc can be set lower than a target temperature of the circulating water.

FIG.7is a diagram showing another example of the operation pattern of the Peltier element4and the heater6in the present embodiment. As shown inFIG.7, instead of setting one operation switching temperature Tc, an operation switching temperature Tc1when the water temperature increases and an operation switching temperature Tc2when the water temperature decreases may be set to different temperatures to provide hysteresis. In this case, the control device8switches to the cooling operation when the temperature of the temperature sensor7becomes equal to or higher than the operation switching temperature Tc1during the heating operation of the Peltier element4, and switches to the heating operation when the temperature of the temperature sensor7becomes equal to or lower than the operation switching temperature Tc2during the cooling operation of the Peltier element4. A difference between the operation switching temperature Tc1and the operation switching temperature Tc2may be, for example, about 1° C. With such hysteresis, it is possible to prevent frequent switching between the heating operation and the cooling operation of the Peltier element4.

FIG.8is a flowchart showing a method of controlling the temperature of circulating water executed by the control device8. Upon receiving an input of an instruction to start activation of the automatic analyzer, the control device8executes processing shown inFIG.8in accordance with a program stored in a memory (not shown).

In step S11, the control device8determines whether a water temperature Tw detected by the temperature sensor7is higher than the operation switching temperature Tc. When the water temperature Tw is higher than the operation switching temperature Tc (Yes), the processing proceeds to step S12, and the control device8performs a cooling operation of the Peltier element4. When the water temperature Tw is equal to or lower than the operation switching temperature Tc (No), the processing proceeds to step S13, and the control device8performs a heating operation on the Peltier element4.

Next, in step S14, the control device8determines an input to the heater6according to the water temperature Tw and a predetermined target water temperature of the circulating water, and controls the water temperature by changing the input by PID control or the like.

Next, in step S15, the control device8determines whether measurement of the reaction liquid in the reaction vessel2is ended. When the measurement is ended (Yes), the processing is ended. When the measurement is not ended (No), the processing returns to step S11.

<About Operation Rate of Peltier Element>

FIG.9is a diagram showing a method of setting an operation rate of the Peltier element4when activating the automatic analyzer. InFIG.9, a vertical axis represents the operation rate of the Peltier element4, a positive value represents an operation rate of the cooling operation, and a negative value represents an operation rate of the heating operation. A horizontal axis indicates the water temperature Tw detected by the temperature sensor7at the time of activation.

At the time of activation of the automatic analyzer, when the water temperature Tw detected by the temperature sensor7is equal to or lower than the operation switching temperature Tc, the Peltier element4may be always subjected to a heating operation at an operation rate of 100%. Alternatively, as shown inFIG.9, an operating condition of the Peltier element4may be changed according to the water temperature Tw at the time of activation. As shown inFIG.9, when the water temperature Tw at the time of activation is low, the Peltier element4is subjected to a heating operation, and when the water temperature Tw at the time of activation is high, the Peltier element4is subjected to a cooling operation, and furthermore, by changing the operation rate of the Peltier element4according to the water temperature Tw at the time of activation, the water temperature in the reaction tank1can be made to reach the target temperature more quickly. The water temperature Tw at the time of activation at which the operation rate of the Peltier element4becomes 0% can be set to, for example, equal to or lower than the operation switching temperature Tc. The water temperature Tw at which a heating operation rate of the Peltier element4is set to 100% and the water temperature Tw at which a cooling operation rate is set to 100% can be freely set in advance before shipment of the automatic analyzer, and is stored in the storage device of the control device8.

The operation rate of the Peltier element4can be controlled by switching at a constant current and changing a ratio between ON and OFF. Instead of changing the operation rate, a capacity of the Peltier element4may be changed by changing a current flowing through the Peltier element4.

FIG.10is a graph schematically showing changes in water temperature in an operation method according to an example in the related art and the operation method according to the present embodiment. As shown inFIG.10, by performing a heating operation on the Peltier element4when the water temperature is equal to or lower than the operation switching temperature Tc as in the present embodiment, the water temperature can be made to reach a target temperature Ts faster than in the example in the related art, and the automatic analyzer can be quickly started up. In the example in the related art, when a capacity of the heater is increased in order to rapidly increase a liquid temperature, the heater becomes large, the device becomes large, and cost of the heater and the power supply increases. In contrast, according to the present embodiment, when there is an extra start-up time, a capacity of the heater6can be reduced, so that it is possible to reduce a size of the heater6and to reduce cost required for the heater6.

Summary of First Embodiment

As described above, the automatic analyzer in the present embodiment includes: the reaction tank1configured to hold circulating water (a liquid) in which the reaction vessel2configured to contain a reaction liquid is to be immersed; the pump3configured to circulate the circulating water and supply the circulating water to the reaction tank1; the heater6configured to heat the circulating water; the Peltier element4configured to heat and cool the circulating water; the temperature sensor7configured to detect a temperature of the circulating water; and the control device8configured to control an output of the heater6and an output of the Peltier element4based on the temperature detected by the temperature sensor. Thus, by combining the heater6and the Peltier element4capable of heating and cooling, a total heating capacity of the circulating water can be improved without increasing the capacity of the heater6. Therefore, even when an ambient air temperature is low, a liquid temperature of the reaction tank1can be increased to a predetermined temperature more quickly. For example, when the water temperature is increased to a certain extent, the water temperature of the circulating water can be stabilized by performing a cooling operation of the Peltier element4.

Second Embodiment

In the first embodiment described above, the operation rate of the Peltier element4is determined based on the water temperature of the circulating water when activating the automatic analyzer. In a second embodiment, a method of determining the operation rate of the Peltier element4when a water temperature of circulating water is stable will be proposed. Since a configuration of the automatic analyzer in the present embodiment is the same as that of the first embodiment, the description thereof will be omitted.

<About Operation Rate of Peltier Element>

FIG.11is a diagram showing a method of setting the operation rate of the Peltier element4in the second embodiment. InFIG.11, a vertical axis is similar as that inFIG.9. A horizontal axis indicates an operation rate of the heater6in a state where the water temperature Tw detected by the temperature sensor7is stable after a certain amount of time elapses after the activation. In the present embodiment, as shown inFIG.11, at a time point when the water temperature Tw detected by the temperature sensor7is stabilized to some extent, the control device8changes the operation rate of the Peltier element4according to the operation rate of the heater6or an input of the heater6, and changes a cooling capacity and a heating capacity of the Peltier element4. When the operation rate of the heater6is high, it is estimated that a heat load of the reaction tank1or the like, that is, a heat radiation amount is large, and as the operation rate of the heater6is high, the cooling capacity of the Peltier element4decreases, and when the operation rate of the heater6is high, the heating capacity of the Peltier element4increases. The operation rate of the heater6when the operation rate of the Peltier element4is 0% can be set to 50%, for example. The operation rate of the heater6at which a heating operation rate of the Peltier element4is set to 100% and the operation rate of the heater6at which a cooling operation rate is set to 100% can be freely set in advance before shipment of the automatic analyzer, and is stored in the storage device of the control device8.

FIG.12is a diagram showing a method of setting the operation rate of the Peltier element4according to a modification of the second embodiment. InFIG.11, the operation rate of the Peltier element4is linearly changed. In contrast, as shown inFIG.12, the operation rate of the Peltier element4may be changed in a stepwise manner, and hysteresis may be provided when the operation rate of the heater6increases and decreases.

In order to avoid the operation from becoming unstable, the operation rate of the Peltier element4based onFIGS.11and12is not constantly changed, but may be performed at a certain time interval.

Summary of Second Embodiment

In an automatic analyzer in the example in the related art, a cooling unit performs a cooling operation regardless of a heat load that varies depending on an ambient air temperature, and thus power consumption of the heater tends to increase. In contrast, as in the present embodiment, by controlling the operation rate of the Peltier element4and the operation rate of the heater6according to the heat load, unnecessary cooling and heating are not performed, and power consumption can be reduced.

Third Embodiment

<About Operation Rate of Peltier Element>

FIG.13is a diagram showing a method of setting the operation rate of the Peltier element4in a third embodiment. InFIG.13, a vertical axis is similar as that inFIG.9. A horizontal axis indicates a difference between an operation rate of the heater6and an operation rate of the Peltier element4in a state where the water temperature Tw detected by the temperature sensor7is stable after a certain amount of time elapses after activation. The difference between the operation rate of the heater6and the operation rate of the Peltier element4in a state where the water temperature Tw is stable is considered to represent a total heating amount at that time, that is, a heat load of the reaction tank1and the like. Therefore, the control device8changes the operation rate of the Peltier element4according to the difference between the operation rate of the heater6and the operation rate of the Peltier element4. Actually, the operation rate of the heater6may be multiplied by a constant A, and the operation rate of the Peltier element4may be multiplied by a constant B, so that the horizontal axis inFIG.13may be defined as “A×operation rate of heater−B×operation rate of Peltier element”.

FIG.13shows a graph when the operation rate of the heater6is higher than the operation rate of the Peltier element4, but a line in the graph inFIG.13shifts according to a balance between the operation rate of the heater6and the operation rate of the Peltier element4(a balance between a capacity of the heater6and a capacity of the Peltier element4).

In order to avoid the operation from becoming unstable, the operation rate of the Peltier element based onFIG.13is not constantly changed, but may be performed at a certain time interval.

Summary of Third Embodiment

As described above, as in the present embodiment, by controlling the operation rate of the Peltier element4and the operation rate of the heater6according to the heat load, unnecessary cooling and heating are not performed, and power consumption can be reduced.

Fourth Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.14is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer according to a fourth embodiment. The automatic analyzer in the present embodiment is different from the configuration of the first embodiment in that an air temperature sensor15configured to detect an ambient air temperature is further provided. The other configurations are similar as those in the first embodiment, and thus the description thereof will be omitted. The air temperature sensor15outputs a detection signal of an air temperature to the control device8.

<About Operation Rate of Peltier Element>

FIG.15is a diagram showing a method of setting the operation rate of the Peltier element in the present embodiment. InFIG.15, a vertical axis is similar as that inFIG.9. A horizontal axis indicates the ambient air temperature detected by the air temperature sensor15. The lower an air temperature is, the larger a heat radiation amount from the reaction tank1or the like to surroundings, that is, the larger a heat load is. Therefore, in the present embodiment, the control device8performs a heating operation on the Peltier element4when the ambient air temperature detected by the air temperature sensor15is lower than a predetermined air temperature, and controls the operation rate of the Peltier element4such that the operation rate of the Peltier element4becomes higher as the ambient air temperature is lower. When the ambient air temperature detected by the air temperature sensor15is equal to or higher than a predetermined air temperature, a cooling operation of the Peltier element4is performed, and the operation rate of the Peltier element4becomes higher as the ambient air temperature is higher. The ambient air temperature (the above-described predetermined air temperature: the air temperature when switching between the heating operation and the cooling operation) at which the operation rate of the Peltier element4is 0% can be set to, for example, a temperature lower than a target temperature of the circulating water.

FIG.16is a diagram showing a method of setting the operation rate of the Peltier element4according to a modification of the fourth embodiment. InFIG.15, the operation rate of the Peltier element4is linearly changed. In contrast, as shown inFIG.16, the operation rate of the Peltier element4may be changed in a stepwise manner, and hysteresis may be provided when the operation rate of the heater6increases and decreases.

In order to avoid the operation from becoming unstable, the operation rate of the Peltier element4based onFIGS.15and16is not constantly changed, but may be performed at a certain time interval.

Summary of Fourth Embodiment

As described above, as in the present embodiment, by controlling the operation rate of the Peltier element4and the operation rate of the heater6according to the heat load, unnecessary cooling and heating are not performed, and power consumption can be reduced.

Fifth Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.17is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer according to a fifth embodiment. The automatic analyzer in the present embodiment is different from the configuration of the first embodiment in that a temperature sensor16provided between the reaction tank1and the pump3and configured to detect a temperature of the circulating water is further provided. The temperature sensor16outputs a detection signal of the temperature of the circulating water to the control device8.

<About Operation Rate of Peltier Element>

FIG.18is a diagram showing a method of setting the operation rate of the Peltier element in the present embodiment. InFIG.18, a vertical axis is similar as that inFIG.9. A horizontal axis indicates a difference between a water temperature detected by the temperature sensor7(a first temperature sensor) and a water temperature detected by the temperature sensor16(a second temperature sensor). The present embodiment utilizes the fact that the larger the heat radiation amount from the reaction tank1or the like, the larger the difference between the temperature detected by the temperature sensor7and the temperature detected by the temperature sensor16. Specifically, when the difference between the temperature detected by the temperature sensor7and the temperature detected by the temperature sensor16is equal to or larger than a predetermined value, the control device8performs a heating operation on the Peltier element4, and sets the operation rate to be higher as the temperature difference is larger. When the temperature difference between the two temperature sensors7and16is smaller than a predetermined value, the control device8performs a cooling operation of the Peltier element4, and sets the operation rate of the Peltier element4to be higher as the temperature difference is smaller. The temperature difference between the two temperature sensors7and16when the operation rate of the Peltier element4is 0% (the above-described predetermined value: the air temperature when switching between the heating operation and the cooling operation) can be set to, for example, less than 1° C.

FIG.19is a diagram showing a method of setting the operation rate of the Peltier element4according to a modification of the fifth embodiment. InFIG.18, the operation rate of the Peltier unit is linearly changed. In contrast, as shown inFIG.19, the operation rate of the Peltier element4may be changed in a stepwise manner, and hysteresis may be provided when the operation rate of the heater6increases and decreases.

In order to avoid the operation from becoming unstable, the operation rate of the Peltier element4based onFIGS.18and19is not constantly changed, but may be performed at a certain time interval.

Sixth Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.20is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer according to a sixth embodiment. The automatic analyzer in the present embodiment differs from the configuration of the first embodiment in that the Peltier unit5is disposed downstream of the heater6. In the present embodiment, the control device8controls the cooling capacity or the heating capacity of the Peltier element4according to the water temperature Tw of the circulating water detected by the temperature sensor7and the target temperature. The cooling capacity or heating capacity of the Peltier element4is controlled by changing a voltage application direction and operation rate of the Peltier element4.

More specifically, when the water temperature Tw detected by the temperature sensor7at the start of an operation is equal to or lower than a predetermined value, the control device8operates the heater6at a constant output, performs a heating operation on the Peltier element4, and controls the heating capacity or the cooling capacity of the Peltier element4according to the water temperature Tw detected by the temperature sensor7. During the operation of the heater6, at a time point when a temperature of the temperature sensor7is stabilized, and when the operation rate of the Peltier element4is equal to or smaller than a predetermined value in a case where the Peltier element4is in a cooling operation or in a heating operation, the control device8stops the heater6and controls a temperature of the circulating water by the Peltier element4.

Summary of Sixth Embodiment

As described above, according to the present embodiment, when a heating load is small, the heater6is stopped and the temperature of the circulating water is controlled only by the Peltier element4, thereby achieving a power-saving operation.

Seventh Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.21is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer according to a seventh embodiment. The automatic analyzer in the present embodiment is different from the configuration of the first embodiment in that a radiator60is provided instead of the Peltier unit5and heat of the circulating water is radiated to the air by the radiator60to cool the circulating water.

The radiator60includes the liquid jacket9, the fins51, and the fan52. A detailed configuration of the radiator60will be described later. An operation of the fan52of the radiator60is controlled by the control device8.

<Configuration Example of Radiator>

FIG.22is a cross-sectional view showing a configuration example of the radiator60. The radiator60includes the liquid jacket9, the fins51, the fan52, the thermal interface201such as grease, and the fin base206. The liquid jacket9is connected to the fin base206via the thermal interface201. Heat from the liquid jacket9is conducted from the fin base206to the fins51via the thermal interface201. Heat is radiated from the fins51and the fin base206to the air flowing between the fins51by the fan52. A structure of the liquid jacket9can be similar as a structure illustrated in the first embodiment (FIG.3or4).

FIG.23is a schematic diagram showing a radiator70having another structure in a modification of the seventh embodiment. A left side ofFIG.23shows the radiator70viewed from a first direction. A right side ofFIG.23shows the radiator70viewed from a second direction orthogonal to the first direction. The radiator70includes a pipe53through which circulating water flows, instead of the liquid jacket9, the fins51, the thermal interface201, and the fin base206. The pipe53is connected to the tube13(not shown inFIG.23). The pipe53may be made of metal such as stainless steel. The circulating water flows through the pipe53, air is caused to flow around the pipe53by the fan52, and heat of the circulating water is radiated from the pipe53to the air.

Although the fans52of the radiators60and70may be constantly operated, the following control may be performed. The control device8stops the fan52when the temperature detected by the temperature sensor7at the time of activation is lower than a predetermined value. Accordingly, the water temperature can quickly reach the target temperature. Further, the control device8stops the fan52when the operation rate of the heater6is equal to or more than a predetermined value in a state where the water temperature is stable. Accordingly, power consumption in a steady state can be reduced.

In the present embodiment, as in the second embodiment, an operation (cooling) and stop of the fan52may be controlled according to the operation rate of the heater6or the input of the heater6. In this case, the control device8operates the fan52when the operation rate or an applied voltage of the heater6is smaller than a predetermined value, and stops the fan52when the operation rate or the applied voltage of the heater6is equal to or larger than the predetermined value.

Summary of Seventh Embodiment

As described above, according to the present embodiment, it is possible to reduce cost by using a radiator having a relatively simple structure for cooling circulating water.

Eighth Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.24is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer according to an eighth embodiment. The automatic analyzer in the present embodiment is different from a configuration of the seventh embodiment in that the air temperature sensor15configured to detect an ambient air temperature is further provided. The other configurations are similar as those in the seventh embodiment, and thus the description thereof will be omitted. The air temperature sensor15outputs a detection signal of an air temperature to the control device8.

In the present embodiment, the control device8stops the fan52when the ambient air temperature detected by the air temperature sensor15is lower than a predetermined value, and operates the fan52when the ambient air temperature is equal to or higher than the predetermined value. The predetermined value for stopping the fan52may be, for example, a temperature lower than the target temperature of the circulating water. Accordingly, the water temperature can be made to reach the target temperature faster than that in the related art, and the automatic analyzer can be quickly started up.

Ninth Embodiment

<Configuration Example of Vicinity of Reaction Tank of Automatic Analyzer>

FIG.25is a schematic diagram showing a configuration in the vicinity of the reaction tank1in the automatic analyzer in the ninth embodiment. The automatic analyzer in the present embodiment is different from the configuration of the seventh embodiment in that the temperature sensor16provided between the reaction tank1and the pump3and configured to detect a temperature of the circulating water is further provided. The temperature sensor16outputs a detection signal of the temperature of the circulating water to the control device8.

In the present embodiment, the control device8stops the fan52when the temperature detected by the temperature sensor7at the time of activation is lower than a predetermined value. Accordingly, the water temperature can quickly reach the target temperature. Further, the control device8stops the fan52when a temperature difference between the temperature sensor7and the temperature sensor16is equal to or larger than a predetermined value when the water temperature is stable. Accordingly, it is possible to reduce power consumption in a steady state.

Modification

The present disclosure is not limited to the above-described embodiment, and includes various modifications. For example, the embodiments described above have been described in detail to facilitate understanding of the present disclosure, and it is not necessary to include all of the configurations described. A part of one embodiment can be replaced with a configuration of another embodiment. A configuration of another embodiment can be added to a configuration of one embodiment. A part of a configuration of each embodiment may be added, deleted, or replaced with a part of a configuration of another embodiment.

REFERENCE SIGNS LIST