Patent Description:
X-rays are electromagnetic waves having wavelengths of <NUM> to <NUM> angstroms (Å), and are widely used, due to their ability to penetrate objects, in medical apparatuses for imaging the inside of a living body or in non-destructive testing equipment for industrial use.

An X-ray apparatus using X-rays may obtain X-ray images of an object by transmitting X-rays emitted from an X-ray source through an object and detecting a difference in intensities of the transmitted X-rays via an X-ray detector. The X-ray images may be used to examine an internal structure of an object and diagnose a disease of the object. The X-ray apparatus facilitates observation of an internal structure of an object by using a principle in which penetrating power of an X-ray varies depending on the density of the object and atomic numbers of atoms constituting the object. As a wavelength of an X-ray decreases, penetrating power of the X-ray increases and an image on a screen becomes brighter.

Prior art document <CIT> discloses a mobile X-ray imaging apparatus and a method of controlling the mobile X-ray apparatus. The mobile X-ray imaging apparatus includes an X-ray source, a battery supplying operating power to the X-ray source, a charger to charge the battery, and a controller to block charging while X-rays are radiated.

Prior art document <CIT> discloses a battery pack, a method of controlling the same, and an energy storage system including the battery pack.

One or more exemplary embodiments may provide a mobile X-ray apparatus including lithium ion batteries.

According to a first aspect of the invention, there is provided a mobile X-ray apparatus according to claim <NUM>. The mobile X-ray apparatus includes: an X-ray radiation device; a controller configured to control the X-ray radiation device; a power supply configured to supply operating power to the X-ray radiation device and the controller via a lithium ion battery and to control overcurrent that occurs during X-ray emission by the X-ray radiation device; and a charger configured to charge the power supply.

The power supply includes a first temperature sensor configured to detect a first temperature of the power supply, : a battery management system (BMS) configured to use the first temperature sensor to monitor the first temperature of the power supply and determine whether the power supply is overheated, and a second temperature sensor configured to detect a second temperature within the power supply, the controller being further configured to directly monitor information about the second temperature detected by the second temperature sensor. The power supply may include a discharge field effect transistor (FET) configured to control the overcurrent and including a plurality of FETs connected in parallel; and a charge FET.

The discharge FET and the charge FET may be further configured to control a path of a discharge current or a charge current when the lithium ion battery is discharged or charged.

The BMS may be further configured to detect the state of the power supply and control a charge path and a discharge path by turning on/off the discharge FET and the charge FET.

The BMS may be further configured to control an operation of a protection circuit for protection against at least one of over-discharge, overcurrent, overheating, and unbalancing between cells in the lithium ion battery.

The power supply may further include a large-capacity current sensor and a small-capacity current sensor, and the BMS may be further configured to detect, during the X-ray emission by the X-ray radiation device, the overcurrent by activating the large-capacity current sensor.

The mobile X-ray apparatus may further include a current sensor located at an output terminal of the charger in order to detect a charge current.

The controller, the power supply, and the charger may each be embodied in a different module.

The power supply includes a temperature sensor configured to detect a temperature within the power supply, and the controller may be further configured to directly monitor information about a temperature detected by the temperature sensor.

The power supply and the charger may respectively include interrupt pins that can be directly controlled by the controller, and the controller may be further configured to respectively turn off the power supply and the charger via the interrupt pins.

The charger may be a wireless charging system composed of a transmitting module and a receiving module.

The charger may be further configured to receive power wirelessly from the outside and charge the power supply based on the received power.

The charger may be further configured to stop charging of the power supply when a low current state, where a charge current is less than a specific reference value, remains for a specific amount of time.

The charger may be further configured to restart the charging of the power supply when a voltage of the lithium ion battery is lower than a specific reference value.

According to a second aspect of the invention, there is provided a method for controlling a mobile X-ray apparatus according to claim <NUM>.

The above and/or other aspects will become more apparent by describing certain exemplary embodiments, with reference to the accompanying drawings, in which:.

Certain exemplary embodiments are described in greater detail below with reference to the accompanying drawings.

In the following description, the same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of exemplary embodiments. Thus, it is apparent that exemplary embodiments can be carried out without those specifically defined matters. Also, well-known functions or constructions are not described in detail since they would obscure exemplary embodiments with unnecessary detail.

The term "part" or "portion" used herein may be implemented using hardware or software, and according to exemplary embodiments, a plurality of "parts" or "portions" may be formed as a single unit or element, or one "part" or "portion" may include a plurality of units or elements.

In the present specification, an image may include a medical image obtained by a magnetic resonance imaging (MRI) apparatus, a computed tomography (CT) apparatus, an ultrasound imaging apparatus, an X-ray apparatus, or another medical imaging apparatus.

Furthermore, in the present specification, an "object" may be a target to be imaged and may include a human, an animal, or a part of a human or animal. For example, the object may include a body part (an organ, tissue, etc.) or a phantom.

<FIG> is an external view and block diagram of an X-ray apparatus <NUM> implemented as a mobile X-ray apparatus, according to an exemplary embodiment.

Referring to <FIG>, the X-ray apparatus <NUM> according to the present exemplary embodiment includes an X-ray radiation device <NUM> for generating and emitting X-rays, an input device <NUM> for receiving a command from a user, a display <NUM> for providing information to the user, a controller <NUM> for controlling the X-ray apparatus <NUM> according to the received command, and a communication unit <NUM>, i.e., a communication device or interface, for communicating with an external device.

The X-ray radiation device <NUM> may include an X-ray source for generating X-rays and a collimator for adjusting a region irradiated with the X-rays generated by the X-ray source.

When the X-ray apparatus <NUM> is implemented as a mobile X-ray apparatus, a main body <NUM> connected to the X-ray radiation device <NUM> is freely movable, and an arm <NUM> connecting the X-ray radiation device <NUM> and the main body <NUM> to each other is rotatable and linearly movable. Thus, the X-ray radiation device <NUM> may be moved freely in a three-dimensional (3D) space.

The input device <NUM> may receive commands for controlling imaging protocols, imaging conditions, imaging timing, and locations of the X-ray radiation device <NUM>. The input device <NUM> may include a keyboard, a mouse, a touch screen, a microphone, a voice recognizer, etc..

The display <NUM> may display a screen for guiding a user's input, an X-ray image, a screen for displaying a state of the X-ray apparatus <NUM>, and the like.

The controller <NUM> may control imaging conditions and imaging timing of the X-ray radiation device <NUM> according to a control command input by the user and generate a medical image based on image data received from an X-ray detector <NUM>. The controller <NUM> may control a position or orientation of the X-ray radiation device <NUM> according to imaging protocols and a position of an object.

The controller <NUM> may include a memory configured to store programs for performing the operations of the X-ray apparatus <NUM> and a processor or a microprocessor configured to execute the stored programs. The controller <NUM> may include a single processor or a plurality of processors or microprocessors. When the controller <NUM> includes the plurality of processors, the plurality of processors may be integrated onto a single chip or be physically separated from one another.

A holder <NUM> may be formed on the main body <NUM> to accommodate the X-ray detector <NUM>. A charging terminal may be disposed in the holder <NUM> to charge the X-ray detector <NUM>. Thus, the holder <NUM> may be used to accommodate and to charge the X-ray detector <NUM>.

The input device <NUM>, the display <NUM>, the controller <NUM>, and the communication unit <NUM> may be provided on the main body <NUM>. Image data acquired by the X-ray detector <NUM> may be transmitted to the main body <NUM> for image processing, and then the resulting image may be displayed on the display <NUM> or transmitted to an external device via the communication unit <NUM>.

The controller <NUM> and the communication unit <NUM> may be separate from the main body <NUM>, or only some components of the controller <NUM> and the communication unit <NUM> may be provided on the main body <NUM>.

The X-ray apparatus <NUM> may be connected to external devices such as a server <NUM>, a medical apparatus <NUM>, and/or a portable terminal <NUM> (e.g., a smart phone, a tablet PC, or a wearable device) in order to transmit or receive data via the communication unit <NUM>.

The communication unit <NUM> may include at least one component that enables communication with an external device. For example, the communication unit <NUM> may include at least one of a local area communication module, a wired communication module, and a wireless communication module.

The communication unit <NUM> may receive a control signal from an external device and transmit the received control signal to the controller <NUM> so that the controller <NUM> may control the X-ray apparatus <NUM> according to the received control signal.

Alternatively, by transmitting a control signal to an external device via the communication unit <NUM>, the controller <NUM> may control the external device according to the transmitted control signal. For example, the external device may process data according to a control signal received from the controller <NUM> via the communication unit <NUM>.

The communication unit <NUM> may further include an internal communication module that enables communications between components of the X-ray apparatus <NUM>. A program for controlling the X-ray apparatus <NUM> may be installed on the external device and may include instructions for performing some or all of the operations of the controller <NUM>.

The program may be preinstalled on the portable terminal <NUM>, or a user of the portable terminal <NUM> may download the program from a server providing an application for installation. The server for providing an application may include a recording medium having the program recorded thereon.

<FIG> is an external view of the X-ray detector <NUM>.

As described above, the X-ray detector <NUM> used in the X-ray apparatus <NUM> may be implemented as a portable X-ray detector. The X-ray detector <NUM> may be equipped with a battery for supplying power to operate wirelessly, or as shown in <FIG>, may operate by connecting a charge port <NUM> to a separate power supply via a cable C.

A case <NUM> maintains an external appearance of the X-ray detector <NUM> and has therein a plurality of detecting elements for detecting X-rays and converting the X-rays into image data, a memory for temporarily or permanently storing the image data, a communication module for receiving a control signal from the X-ray apparatus <NUM> or transmitting the image data to the X-ray apparatus <NUM>, and a battery. Further, image correction information and intrinsic identification (ID) information of the X-ray detector <NUM> may be stored in the memory, and the stored ID information may be transmitted together with the image data during communication with the X-ray apparatus <NUM>.

<FIG> is a block diagram of an X-ray apparatus <NUM> according to an exemplary embodiment.

Referring to <FIG>, the X-ray apparatus <NUM> according to the present exemplary embodiment may include an X-ray radiation device <NUM>, a controller <NUM>, a power supply <NUM> including a lithium ion battery <NUM>, and a charger <NUM>. The X-ray apparatus <NUM> of <FIG> may be implemented as a mobile X-ray apparatus as shown in <FIG>, and <FIG> illustrates only components related to the present exemplary embodiment. Thus, as understood by those of ordinary skill in the art, the X-ray apparatus <NUM> may further include common components in addition to those shown in <FIG>.

The described-above with respect to the X-ray radiation device <NUM> and the controller <NUM> of <FIG> may apply to the X-ray radiation device <NUM> and the controller <NUM>, respectively.

The power supply <NUM> may supply operating power to the X-ray radiation device <NUM> and the controller <NUM> via the lithium ion battery <NUM>. Further, the power supply <NUM> may supply operating power to the components of the X-ray apparatus <NUM> that require the operating power. For example, the power supply <NUM> may supply operating power to the input device <NUM>, the display <NUM>, and the communication unit <NUM> of the X-ray apparatus <NUM> via the lithium ion battery <NUM>.

The power supply <NUM> may control overcurrent that occurs during emission of X-rays by the X-ray radiation device <NUM>. In other words, as the X-ray radiation device <NUM> emits X-rays, overcurrent that is higher than a normal operating current may flow in the power supply <NUM>, and the power supply <NUM> may control the overcurrent. According to an exemplary embodiment, in order to control overcurrent, the power supply <NUM> may include a circuit consisting of a discharge field effect transistor (FET) and a charge FET connected in parallel. According to an exemplary embodiment, in order to control the overcurrent, the power supply <NUM> may include a circuit including current sensors having different capacities for measuring the amount of discharge current.

The charger <NUM> may charge the power supply <NUM>. In detail, the charger <NUM> may supply a charging power to charge the lithium ion battery <NUM> of the power supply <NUM>. The charging power may be a power generated by the charger <NUM>. According to an exemplary embodiment, the charger <NUM> may be combined with an external power supply to receive power from the external power supply. The charger <NUM> may then control the received power according to a user input or arithmetic operations performed within the X-ray apparatus <NUM>, to supply a charging power to the lithium ion battery <NUM>.

The power supply <NUM>, the charger <NUM>, and the controller <NUM> may each include a communication interface that enables communication therebetween. For example, the power supply <NUM>, the charger <NUM>, and the controller <NUM> may communicate with one another via their communication interfaces according to a controller area network (CAN) protocol.

The power supply <NUM>, the charger <NUM>, and the controller <NUM> may each be separately embodied in a different module. Thus, the controller <NUM> does not need to directly monitor a high voltage, and a high voltage circuit is not needed within the controller <NUM>. This may consequently reduce the risks associated with the high voltage circuit, thereby effectively improving stability. When the power supply <NUM>, the charger <NUM>, and the controller <NUM> are each composed of a different module, they may be used for different mobile X-ray apparatuses and thus share a common platform. Further, by applying a shielded case to each separate module of the power supply <NUM>, the charger <NUM>, and the controller <NUM>, it is possible to suppress Electro Magnetic Interference (EMI)/Electro Magnetic Compatibility (EMC) noise that may occur therebetween.

<FIG> illustrates an X-ray apparatus <NUM> according to an exemplary embodiment.

Referring to <FIG>, a power supply <NUM> may include a lithium ion battery <NUM>, a battery management system (BMS) <NUM>, a discharge FET <NUM>, and a charge FET <NUM>. <FIG> illustrates only components related to the present exemplary embodiment. Thus, one of ordinary skill in the art will understand that the X-ray apparatus <NUM> may further include common components other than those shown in <FIG>.

The lithium ion battery <NUM> is a type of secondary battery that includes a combination of a plurality of battery cells connected to each other. For example, the lithium ion battery <NUM> may include a total of <NUM> cells, e.g., a serial connection of <NUM> cells which are connected in parallel as <NUM> strings, e.g., <NUM> parallel cell groups each including <NUM> serially connected cells.

The BMS <NUM> may detect a state of the lithium ion battery <NUM>, such as a voltage and a temperature thereof. According to an exemplary embodiment, the BMS <NUM> may include a battery stack monitor circuit designed to monitor a voltage of the lithium ion battery <NUM> and a temperature of a battery cell. The BMS <NUM> may control and manage the power supply <NUM> based on the state of the lithium ion battery <NUM>. The BMS <NUM> may control on/off states of the charge FET <NUM> and the discharge FET <NUM> to manage a charge path and a discharge path, respectively.

The BMS <NUM> may operate a protection circuit based on the state of the lithium ion battery <NUM>. In other words, the BMS <NUM> may operate the protection circuit to protect the lithium ion battery <NUM>. In detail, based on the state of the lithium ion battery <NUM>, the BMS <NUM> may operate the protection circuit to protect the lithium ion battery <NUM> against at least one of over-discharge, overcurrent, overheating, and unbalancing between battery cells.

The BMS <NUM> may operate the protection circuit when the lithium ion battery <NUM> is in an over-discharged state where a voltage of the lithium ion battery <NUM> is lower than a reference voltage. For example, if a voltage of the lithium ion battery <NUM> drops to less than or equal to 275V, the BMS <NUM> may operate a shutdown circuit to turn itself off. The BMS <NUM> may operate the protection circuit when the lithium ion battery <NUM> is in an overcurrent state where a current of the lithium ion battery <NUM> is higher than a reference value. For example, if the current of the lithium ion battery <NUM> is greater than or equal to 40A, the BMS <NUM> may operate a shutdown circuit to reset itself. The BMS <NUM> may operate the protection circuit when the lithium ion battery <NUM> is in an overheated state where a temperature of the lithium ion battery <NUM> is higher than a reference value. For example, if the temperature of the lithium ion battery <NUM> is greater than or equal to <NUM>, the BMS <NUM> may operate the protection circuit to shut off a charge path and a discharge path. Further, when the lithium ion battery <NUM> is unbalanced between cells, the BMS <NUM> may operate the protection circuit. For example, if a voltage difference between cells in the lithium ion battery <NUM> remains greater than or equal to <NUM> V for <NUM> seconds or more, the BMS <NUM> may operate a shutdown circuit to turn itself off.

The BMS <NUM> may communicate with a controller <NUM> via a communication interface <NUM>, e.g., according to a CAN protocol. Further, the charger <NUM> may communicate with the controller <NUM> via a communication interface <NUM>, e.g., according to the CAN protocol. The BMS <NUM> may supply a DC power to each component of the X-ray apparatus <NUM> including the controller <NUM>.

The discharge FET <NUM> may include a plurality of FETs <NUM> connected in parallel. Since overcurrent may flow in the power supply <NUM> during X-ray emission by the X-ray radiation device <NUM>, the FETs having a specific capacity in the discharge FET <NUM> may be connected in parallel. In other words, by connecting the FETs having the specific capacity in parallel, a maximum allowable current capacity of the discharge FET <NUM> may be increased. For example, if overcurrent greater than or equal to 300A flows within the power supply <NUM> during X-ray emission by the X-ray radiation device <NUM>, the discharge FET <NUM> may include <NUM> FETs which are connected in parallel and have a capacity of 100A each for the protection against the overcurrent.

According to an exemplary embodiment, the discharge FET <NUM> and the charge FET <NUM> may each include N-channel FETs.

The discharge FET <NUM> and the charge FET <NUM> may control a path of discharge or charge current when the lithium ion battery <NUM> is discharged or charged. According to an exemplary embodiment, when the lithium ion battery <NUM> is discharged, the charge FET <NUM> is turned off, and a discharge current loop may be formed by the discharge FET <NUM>. According to an exemplary embodiment, when the lithium ion battery <NUM> is charged, the discharge FET <NUM> is turned off, and a charge current loop may be formed by a diode or diodes <NUM> included in the discharge FET <NUM> and the charge FET <NUM>. Further, the lithium ion battery <NUM> may be discharged and charged at the same time via the discharge FET <NUM> and the charge FET <NUM>.

While <FIG> shows that a load <NUM> for receiving a power from the lithium ion battery <NUM> includes the controller <NUM> and the X-ray radiation device <NUM>, the load <NUM> may further include other components of the X-ray apparatus <NUM> that require power.

<FIG> is a schematic diagram illustrating discharging of a lithium ion battery <NUM> according to an exemplary embodiment.

When the lithium ion battery <NUM> is discharged, a charge FET <NUM> is turned off since a source (S) voltage of the charge FET <NUM> is higher than a drain (D) voltage. Further, a discharge FET <NUM> is turned on since a drain (D) voltage of the discharge FET <NUM> is higher than a source (S) voltage.

Thus, as shown in <FIG>, a discharge current loop may be formed in a clockwise direction in which a discharge current flows through a load <NUM>, the discharge FET <NUM>, and the lithium ion battery <NUM>. Further, even when the charge FET <NUM> is turned off, discharging of the lithium ion battery <NUM> may be performed normally.

<FIG> is a schematic diagram illustrating charging of a lithium ion battery <NUM> according to an exemplary embodiment.

When the lithium ion battery <NUM> is charged, a discharge FET <NUM> is turned off since a source (S) voltage of the discharge FET <NUM> is higher than a drain (D) voltage thereof. When the discharge FET <NUM> is turned off, a charge current may flow through a diode <NUM> of the discharge FET <NUM>. Further, when the lithium ion battery <NUM> is charged, a charge FET <NUM> is turned on since a drain (D) voltage of the charge FET <NUM> is higher than a source (S) voltage thereof.

Thus, as shown in <FIG>, a charge current loop may be formed in a counter-clockwise direction in which a charge current flows through a charger <NUM>, the lithium ion battery <NUM>, a diode <NUM> of the discharge FET <NUM>, and the charge FET <NUM>. Further, even when the discharge FET <NUM> is turned off, charging of the lithium ion battery <NUM> may be performed normally.

<FIG> is a schematic diagram of an X-ray apparatus <NUM> according to an exemplary embodiment.

Referring to <FIG>, a power supply <NUM> may include a lithium ion battery <NUM>, a BMS <NUM>, a discharge FET <NUM>, a charge FET <NUM>, a shutdown circuit <NUM>, a small-capacity current sensor <NUM>, e.g., a first current sensor, a large-capacity current sensor <NUM>, e.g., a second current sensor, a DC-to-DC (DC-DC) converter <NUM>, and a fuse <NUM>. The X-ray apparatus <NUM> may include a charge current sensor <NUM>, e.g., a third current sensor. Since the lithium ion battery <NUM>, the BMS <NUM>, the discharge FET <NUM>, and the charge FET <NUM> respectively correspond to the lithium ion battery <NUM>, the BMS <NUM>, the discharge FET <NUM>, and the charge FET <NUM> described with reference to <FIG>, detailed descriptions thereof will be omitted below.

The BMS <NUM> may detect current of the lithium ion battery <NUM> by using the current sensors having different capacities, i.e., the small-current sensor and large-capacity current sensor <NUM> and <NUM>. In detail, the BMS <NUM> may detect current flowing in the lithium ion battery <NUM> by using the small-capacity current sensor <NUM>. When overcurrent flows in the lithium ion battery <NUM>, the BMS <NUM> may detect overcurrent flowing in the lithium ion battery <NUM> by using the large-capacity current sensor <NUM>.

The BMS <NUM> may detect, via the small-capacity current sensor <NUM>, current flowing in the lithium ion battery <NUM> by activating the small-capacity current sensor <NUM> while deactivating the large-capacity current sensor <NUM>. Then, when an X-ray radiation device <NUM> emits X-rays, the BMS <NUM> may detect overcurrent that occurs during the X-ray emission via the large-capacity current sensor <NUM> by activating the large-capacity current sensor <NUM> while deactivating the small-capacity current sensor <NUM>. Subsequently, when the X-ray emission is completed, the BMS <NUM> may detect, via the small-capacity current sensor <NUM>, current flowing in the lithium ion battery <NUM> by activating the small-capacity current sensor <NUM> while deactivating the large-capacity current sensor <NUM>. According to an exemplary embodiment, the BMS <NUM> may receive an X-ray emission preparation signal from a controller <NUM> and activate the large-capacity current sensor <NUM> to detect overcurrent occurring during X-ray emission via the large-capacity current sensor <NUM>.

The BMS <NUM> may check the residual amount of the lithium ion battery <NUM> based on the amount of current detected using the small-current sensor and large-capacity current sensor <NUM> and <NUM>. In detail, the BMS <NUM> may use Coulomb counting based gauging to check the residual amount of the lithium ion battery <NUM> based on the detected amount of current.

The X-ray apparatus <NUM> may further include the charge current sensor <NUM> for measuring a charge current at an output terminal <NUM> of the charger <NUM>. When the lithium ion battery <NUM> is charged and discharged at the same time, current measured by the small-current sensor and large-capacity current sensor <NUM> or <NUM> may be a sum of a discharge current and a charge current. Thus, in order to accurately measure a discharge current and a charge current, the X-ray apparatus <NUM> may measure the charge current by using the charge current sensor <NUM>.

The BMS <NUM> may receive signals indicating that the X-ray radiation device <NUM> starts emission of X-rays and that the X-ray radiation device <NUM> completes the emission of X-rays from the controller <NUM> via a communication interface <NUM>.

The BMS <NUM> may turn itself off by using the shutdown circuit <NUM>, e.g., by using a switch included therein. When the BMS <NUM> may check a state of the lithium ion battery <NUM> to detect hazardous conditions such as over-discharge and overcharge, the BMS <NUM> may turn itself off by using the shutdown circuit <NUM> that serves as a protection circuit. When the BMS <NUM> turns itself off, the power being supplied to the controller <NUM> is also cut off, so that the controller <NUM> may turn off.

The fuse <NUM> is designed to stop continuous flowing of excessive current that is greater than a nominal value in the power supply <NUM> and may protect a battery cell when the lithium ion battery <NUM> is subjected to an external short circuit.

The DC-DC converter <NUM> may convert a voltage of the lithium ion battery <NUM> into an operating voltage of the BMS <NUM> or a DC power of the components of the X-ray apparatus <NUM>.

<FIG> is a schematic diagram of an X-ray apparatus according to an exemplary embodiment.

Referring to <FIG>, a power supply <NUM>, a controller <NUM>, and a charger <NUM> may each include a communication interface and communicate with one another via their communication interfaces. For example, the power supply <NUM>, the controller <NUM>, and the charger <NUM> may communicate with one another according to a CAN protocol.

The power supply <NUM> may include a BMS-only temperature sensor <NUM>, e.g., a first temperature sensor. The BMS <NUM> may use the BMS-only temperature sensor <NUM> to monitor a temperature of the power supply <NUM> and determine whether the power supply <NUM> is overheated. For example, if the power supply <NUM> is overheated to a temperature higher than a specific threshold value, the BMS <NUM> may operate a protection circuit that cuts off a charge path and a discharge path. As illustrated, the BMS-only temperature sensor <NUM> may include three sensors or three sensing points, but this is not limiting.

The power supply <NUM> may further include a controller-only temperature sensor <NUM>, e.g., a second temperature sensor, that may be directly monitored by the controller <NUM>. If a communication error occurs between the controller <NUM> and the BMS <NUM>, the controller <NUM> might not be able to receive temperature information of the power supply <NUM> from the BMS <NUM>. The controller <NUM> may monitor the temperature of the power supply <NUM> independently via the controller-only temperature sensor <NUM>. Thus, when a communication error occurs, the controller <NUM> may determine whether to turn off the BMS <NUM> by using the controller-only temperature sensor <NUM> without a need to forcibly turn off the BMS <NUM>.

The power supply <NUM> and the charger <NUM> may respectively include first and second interrupt pins <NUM> and <NUM> that can be directly controlled by the controller <NUM>. The controller <NUM> may respectively transmit disable signals to the power supply <NUM> and the charger <NUM> via the first and second interrupt pins <NUM> and <NUM>, and accordingly turn off the power supply <NUM> and the charger <NUM>. Thus, when it is determined that a temperature of the power supply <NUM> is equal to or higher than a specific threshold value via the controller-only temperature sensor <NUM>, the controller <NUM> may forcibly turn off the power supply <NUM> and the charger <NUM> via the first and second interrupt pins <NUM> and <NUM>, respectively.

When the BMS <NUM> operates a shutdown circuit to turn itself off, a shutdown signal from the BMS <NUM> may be transmitted to the controller <NUM>. After receiving the shutdown signal, the controller <NUM> may monitor whether the BMS <NUM> is shut down for a specific amount of time. If the BMS <NUM> is not shut down for the specific amount of time as a result of monitoring, the controller <NUM> may forcibly turn off the BMS <NUM> via the first interrupt pin <NUM>. For example, after the BMS <NUM> activates a shutdown bit, the controller <NUM> may monitor whether the BMS <NUM> is shut down for <NUM> seconds. If the BMS <NUM> is not shut down for <NUM> seconds, the controller <NUM> may forcibly turn off the BMS <NUM> via the first interrupt pin <NUM>.

<FIG> illustrates an X-ray apparatus according to an exemplary embodiment.

According to an exemplary embodiment, the charger <NUM> may include a wireless charging system including a transmitting module <NUM>, e.g., a transmitter, and a receiving module <NUM>, e.g., a receiver. For example, the charger <NUM> may be a self-inductive wireless charging system. In the charger <NUM>, the transmitting module <NUM> may convert an AC power from an external power supply into a DC power, amplify the DC power, and transmit the amplified DC power wirelessly to the receiving module <NUM> via a transmitting coil. The receiving module <NUM> may rectify the received power to charge the lithium ion battery <NUM>.

As another example, the receiving module <NUM> of the charger <NUM> may receive a power transmitted wirelessly by the transmitting module <NUM> installed externally to the receiving module <NUM> and may rectify the received power to charge the lithium ion battery <NUM>. Thus, an X-ray apparatus <NUM> including the charger <NUM> may be located near the transmitting module <NUM> and may charge the lithium ion battery <NUM> by using the power transmitted wirelessly by the transmitting module <NUM>.

<FIG> is a timing diagram of an operation of charging a lithium ion battery <NUM> according to an exemplary embodiment.

First, during interval A, as the charger <NUM> performs a charging operation, a charge voltage may increase while a charge current remains constant.

Thereafter, during interval B, as the lithium ion battery <NUM> relaxes, the charge current may decrease.

An interval C indicates a low current state in which a charge current less than a specific threshold value remains for a specific amount of time. The charger <NUM> may detect the low current state, as will be described in detail below with reference to <FIG>. If the low current state is detected for a specific amount of time or a specific number of times, the charger <NUM> may stop a charging operation. For example, if the charger <NUM> detects a low current state, in which the charge current is less than or equal to <NUM>. 5A, <NUM> times, the charger <NUM> may stop a charging operation. Thus, if the lithium ion battery <NUM> relaxes, the charger <NUM> may stop the charging operation, thereby preventing unnecessary power consumption.

Subsequently, during interval D, when a voltage of the lithium ion battery <NUM> drops to a preset value, the charger <NUM> may restart the charging operation, and the charge current may also increase.

Thereafter, during interval E, which corresponds to the interval A, as the charger <NUM> performs the charging operation, the charge voltage may increase while the charge current remains constant.

<FIG> is a flowchart of a method of sensing of a low current state by the charger <NUM>, according to an exemplary embodiment.

The charger <NUM> may detect a charge current value (operation S1101).

The charger <NUM> may determine whether the detected charge current value is less than an upper off-state charge current threshold (operation S1103). For example, the upper off-state charge current may be <NUM>.

If the detected charge current value is less than the upper off-state charge current threshold in operation S1103, the charger <NUM> may increase a low current count value by <NUM> (operation S1105). In other words, if the low current count value is increased by <NUM> each cycle to reach a certain count value, e.g., <NUM>, the charger <NUM> may determine that the current has remained low for a certain amount of time.

Otherwise, if the detected charge current value is not less than the upper off-state charge current threshold in operation S1103, the charger <NUM> may determine whether the detected charge current value is greater than a lower on-state charge current threshold (operation S1107). For example, the lower on-state charge current threshold may be <NUM>.

If the detected charge current value is greater than the lower on-state charge current threshold in operation S1107, the charger <NUM> may set the low current count value to <NUM> (operation S1109).

Otherwise, if the detected charge current value is not greater than the lower on-state charge current threshold in operation S1107, the charger <NUM> may detect a charge current value (operation S1101).

The charger <NUM> may determine whether the low current count value is five <NUM> (operation S <NUM>).

If the low current count value is <NUM> in operation S1111, the charger <NUM> may generate a signal indicating that a charging operation is to be stopped after a lapse of a certain amount of time (operation S1113).

Otherwise, if the low current count value is not <NUM> in operation S1111, the charger <NUM> may determine whether the low current count value is <NUM> (operation S1115).

If the low current count value is <NUM> in operation S1115, the charger <NUM> may stop the charging operation (operation S1117). In other words, if the low current count value is <NUM>, the charger <NUM> may determine that the low current state has remained for the certain amount of time and then stop the charging operation.

Otherwise, if the low current count value is not <NUM> in operation S1115, the charger <NUM> may detect a charge current value (operation S1101).

Exemplary embodiments may be implemented through non-transitory computer-readable recording media having recorded thereon computer-executable instructions and data. The non-transitory computer-readable medium may include a compact disc (CD), a digital versatile disc (DVD), a hard disc, a Blu-ray disc, a universal serial bus (USB), a memory card, a read only memory (ROM), and the like. The instructions may be stored as program codes, and when executed by a processor, may generate a predetermined program module to perform a specific operation. When being executed by the processor, the instructions may perform specific operations according to the exemplary embodiments.

Claim 1:
A mobile X-ray apparatus comprising:
an X-ray radiation device (<NUM>) configured to emit X-rays;
a controller (<NUM>) configured to control the X-ray radiation device (<NUM>);
a power supply (<NUM>) comprising a lithium ion battery (<NUM>) and configured to supply operating power to the X-ray radiation device (<NUM>) and the controller (<NUM>) from the lithium ion battery (<NUM>), and to control overcurrent that occurs during emission of the X-rays by the X-ray radiation device (<NUM>); and
a charger (<NUM>) configured to charge the lithium ion battery (<NUM>),
characterised in that the power supply (<NUM>) comprises:
a first temperature sensor (<NUM>) configured to detect a first temperature of the power supply (<NUM>),
a battery management system (<NUM>), BMS, configured to use the first temperature sensor (<NUM>) to monitor the first temperature of the power supply (<NUM>) and determine whether the power supply (<NUM>) is overheated, and
a second temperature sensor (<NUM>) configured to detect a second temperature within the power supply (<NUM>), the controller (<NUM>) being further configured to directly monitor information about the second temperature detected by the second temperature sensor (<NUM>).