JP5108454B2 - Electronics - Google Patents

Description

  The present invention relates to an electronic device capable of detecting a deformation amount of a secondary battery.

  In recent years, secondary batteries have been used as power sources for portable devices such as handy cameras, notebook PCs (Personal Computers), mobile phones, PHSs (Personal Handy phone Systems), and PDAs (Personal Digital Assistants). These electronic devices are becoming smaller and lighter, and secondary batteries are also being made smaller and lighter. Secondary batteries include types such as nickel metal hydride batteries, lead acid batteries, and lithium ion batteries. In particular, lithium ion batteries are easy to reduce in size and weight among types of secondary batteries, and have a high voltage and energy density.

Generally, a secondary battery undergoes thermal decomposition when the temperature rises due to a short circuit inside the battery. If charging is repeated over a long period of time, gas generation and deposits of chemical substances occur due to chemical reactions inside the secondary battery. The chemical reaction inside the secondary battery becomes prominent when charging with a high voltage, when the outside air is at a high temperature, or when the battery itself becomes high temperature due to the generation of heat in the battery itself. Due to the influence, deformation occurs outside the secondary battery. A technique is known in which the temperature of the secondary battery is indirectly derived by detecting the current and voltage applied to the secondary battery during charging, and charging is performed while preventing chemical changes in the secondary battery (for example, patents). Reference 1).
JP 2007-228701 A

  If the technique mentioned above is used, a secondary battery can prevent a deformation | transformation by suppressing the heat | fever generated from itself. However, since the temperature of the secondary battery is indirectly detected by current and voltage, the temperature cannot be accurately grasped. Therefore, although the secondary battery is already in a deformed state, if the detected indirect temperature is low, charging is started again, and further chemical reaction proceeds.

  In order to avoid such a problem, it is possible to install a temperature detection unit directly inside the secondary battery, but it does not directly detect the deformation of the secondary battery, so that it is within the allowable range of deformation. I cannot judge whether or not.

  The present invention has been made in view of the above-described problems of conventional techniques, and an object of the present invention is to provide an electronic device capable of detecting the amount of deformation due to a chemical reaction of a secondary battery. is there.

In solving the above-described problems, according to an aspect of the present invention, a secondary battery, a fixing portion for fixing the secondary battery, a charging circuit for charging the secondary battery, and a predetermined amount in a predetermined portion of the secondary battery a detection unit for detecting a deformation of, and a process changing unit that changes the charging process of the rechargeable battery by the charging circuit and for detecting a predetermined amount of deformation during the charging of the secondary battery, the detection unit includes a light emitting portion A reflection part provided at a predetermined part of the secondary battery for reflecting the light from the light emitting part and a light receiving part for receiving the reflected light. An electronic device is provided that is characterized by detecting quantitative deformation .

  With this configuration, the electric device can always check whether the secondary battery itself has reached a predetermined amount of deformation by a chemical reaction inside the secondary battery, and automatically when the deformation amount exceeds a predetermined allowable range. To change the charging process. Therefore, further deformation of the secondary battery can be prevented.

  With this configuration, the detection unit determines the deformation amount of the secondary battery according to the difference in the amount of light received or received by the light receiving unit that is emitted from the light emitting unit and reflected by the reflecting unit before and after the deformation of the secondary battery. It is possible to grasp and detect a predetermined amount of deformation.

According to another aspect of the present invention, a secondary battery, a fixing portion for fixing the secondary battery, a charging circuit for charging the secondary battery, and a predetermined amount of deformation at a predetermined portion of the secondary battery are detected. A detection unit, and a process changing unit that changes a charging process of the secondary battery by the charging circuit when a predetermined amount of deformation is detected during charging of the secondary battery, and the detection unit includes the light emitting unit and the light emitting unit. The electronic device is provided with a light receiving portion arranged at a position where the optical path is blocked by deformation of the secondary battery.

  With this configuration, the detecting unit can grasp the deformation amount of the secondary battery only by the fact that the light emitted from the light emitting unit has not reached the light receiving unit.

  When the process change unit functions, it is possible to further include a notification unit that notifies that the deformation of the secondary battery has reached a predetermined amount.

  Since the notification unit notifies when the deformation of the secondary battery reaches a predetermined amount, the user can recognize the deformation of the secondary battery, and the physical stress that the deformation of the secondary battery gives to other parts. Can be prevented in advance.

  The change in the charging process may be a stop of charging. With this configuration, the charging process changing unit can stop charging so as not to generate heat from the secondary battery when the deformation of the secondary battery reaches a predetermined amount.

  The change of the charging process may be a change of one or two or more values selected from a group of a target voltage value, a stop current value, and a charging time, which are charging completion conditions for the secondary battery.

  With this configuration, when the deformation of the secondary battery reaches a predetermined amount, the process changing unit lowers the target voltage value of the secondary battery, increases the stop current value of the secondary battery, and shortens the charging time. Make process changes. Therefore, although the charging process of the secondary battery is changed and the amount of charge is reduced, the generation of heat can be suppressed low, so that the deformation of the secondary battery does not need to proceed.

  As described above, the electronic device of the present invention can detect the amount of deformation due to the chemical reaction of the secondary battery and prevent further deformation of the secondary battery.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  The purpose of this embodiment is to prevent the occurrence of further adverse effects due to physical stress generated by deformation, particularly expansion, of the secondary battery. The present embodiment can be applied to various electronic devices such as a handy camera, a notebook PC, and a portable terminal that use a secondary battery, but here, a portable terminal will be described as an example for easy understanding. .

  FIG. 1 is a functional block diagram showing functions of the mobile terminal 100, and FIG. 2 is an external perspective view for explaining a schematic configuration of the mobile terminal 100. The portable terminal 100 includes a terminal control unit 110, a terminal memory 112, a display unit 114, an operation unit 116, a voice input unit 118, a voice output unit 120, a wireless communication unit 122, a secondary battery 124, and the like. The fixing unit 126, the charging circuit 128, the detection unit 130, the process change unit 132, and the notification unit 134 are configured.

  The terminal control unit 110 manages and controls the entire mobile terminal 100 by a semiconductor integrated circuit including a central processing unit (CPU). The terminal control unit 110 naturally performs a communication function using the mobile terminal 100 and a mail delivery function using the program in the terminal memory 112.

  The terminal memory 112 includes a ROM, RAM, EEPROM, nonvolatile RAM, flash memory, HDD (Hard Disk Drive), and the like, and stores programs processed by the terminal control unit 110, audio data, and the like.

  The display unit 114 is provided in the first housing 160 and is configured by a liquid crystal display, an EL (Electro Luminescence), a PDP (Plasma Display Panel), etc., and is stored in the terminal memory 112 or an application via a communication network. A GUI (Graphical User Interface) of a Web browser or an application provided from a relay server (not shown) can be displayed.

  The operation unit 116 is provided in the second housing 162 and includes operation keys such as a keyboard, a cross key, and a joystick, and accepts a user operation input.

  The voice input unit 118 is composed of a voice recognition device such as a microphone in the second housing 162, and converts the user's voice input during a call into an electrical signal that can be processed in the mobile terminal 100.

  The voice output unit 120 is configured by a speaker in the first casing 160, and converts the voice signal of the call partner received by the mobile terminal 100 into voice and outputs the voice. Further, a ring tone, an operation sound by an operation unit 116 described later, an alarm sound, and the like can be output.

  The wireless communication unit 122 performs wireless communication with the base station 140 in the mobile phone network. Examples of such wireless communication include a time division multiplexing method in which a plurality of time slots obtained by time division of frames in the base station 140 are assigned to the channels of the mobile terminal 100 to perform communication.

  The secondary battery 124 is composed of a nickel metal hydride battery, a lead storage battery, a lithium ion battery, or the like. For example, in a commonly used lithium ion battery, lithium ions in the electrolyte are responsible for electrical conduction, and the battery does not contain metallic lithium. Even if the battery capacity is reduced or eliminated, the secondary battery 124 can be used again as a battery by charging.

  The fixing unit 126 fixes the secondary battery 124 to the mobile terminal 100.

  The charging circuit 128 charges the secondary battery 124 using electric power received from the outside. In particular, when the secondary battery 124 to be charged is a lithium ion battery, the charging circuit 128 includes a control circuit that controls the charging power in accordance with the charged amount of the lithium ion battery. For example, the control circuit sets the target voltage value to 4.2 V and stops charging when the terminal voltage reaches the set voltage. Further, when the terminal voltage drops to 3.9 V due to discharging, the charge stop state is released and charging is possible again.

  The detection unit 130 always detects whether or not the deformation of the predetermined portion in the plane vertical direction has reached a predetermined amount in a state where the secondary battery 124 is fixed to the fixing unit 126. The detailed configuration of the detection unit 130 will be described later.

  The process changing unit 132 changes the charging process such as stopping charging or shortening the charging time. The process changing unit 132 stops or relaxes further deformation of the secondary battery 124 by changing the charging process.

  The notification unit 134 deforms a predetermined part of the secondary battery 124 through a text message such as “Battery is inflated” on the display unit 114 and a voice such as “Battery is inflated” on the voice output unit 120. Informs the user that a predetermined amount of deformation has been reached.

  FIG. 3 is a perspective view for explaining an example of notification by the notification unit 134. Here, the notification unit 134 notifies the message through the display unit 114. When the secondary battery 124 detects a predetermined amount of deformation, the notification unit 134 displays a message “battery is inflated” on the display unit 114, to that effect. Communicating to users.

  Next, a specific configuration of the secondary battery 124 fitting in the mobile terminal 100 described above will be described.

  FIG. 4 is an assembly diagram illustrating the fitting of the secondary battery 124 of the mobile terminal 100. Here, a configuration is described in which the secondary battery 124 is fitted into the fixing portion 126 provided on the back side of the second casing 162 of the mobile terminal 100 and the outer side thereof is covered with the secondary battery protection cover 170. By fixing the secondary battery 124 to the fixing portion 126, the charging circuit 128 and the secondary battery 124 are electrically connected, and the charging circuit 128 can charge the secondary battery 124.

  Here, the secondary battery protection cover 170 prevents the secondary battery 124 from dropping and the user from coming into contact with the secondary battery 124 that is relatively heated.

  Referring to FIG. 4, it can be understood that the detection unit 130 provided on the fixed unit 126 side overlaps with the predetermined portion 136 of the secondary battery 124, so that a predetermined amount of deformation of the secondary battery 124 can be detected.

  FIG. 5 is a cross-sectional view of the secondary battery 124 described above. In particular, FIG. 5 (a) shows the appearance immediately after purchase and the BB cross section, and FIG. 5 (b) shows the appearance and CC cross section deformed over time.

  The cross section BB of the secondary battery 124 in FIG. 5A has a rectangular shape in which each side is a straight line. However, the secondary battery 124 in FIG. The CC cross section of the secondary battery 124 swells in the lateral direction, and has a barrel shape. Therefore, if the secondary battery 124 in FIG. 5B continues to be used while being mounted in the mobile terminal 100, the fixing portion 126 and the secondary battery protective lid 170 may be pressed and eventually destroyed. is there. Therefore, in the present embodiment, the deformation is detected in advance by the detection unit 130 described above so that the fixing unit 126 and the secondary battery protection lid 170 are not destroyed. Hereinafter, a detection structure of a predetermined amount of deformation by the detection unit 130 will be described in detail.

  FIG. 6 is a cross-sectional view of FIG. 2A-A for explaining the detection unit 130. Here, a switch arranged in the deformation direction of a predetermined part of the secondary battery 124 is used as the detection unit 130. In order to facilitate understanding, only the secondary battery 124, the detection unit 130, the second housing 162, and the secondary battery protection lid 170 will be described here for the configuration.

  As shown in FIG. 6A, in the conventional configuration in which the detection unit 130 is not provided, there is no means for preventing the deformation of the secondary battery 124, so the secondary battery 124 continues to be deformed. The secondary battery protective cover 170 is pressed. Under such circumstances, once the secondary battery protection cover 170 is removed from the second casing 162, the secondary battery protection cover 170 cannot be attached to the second casing 162 as it was.

  In the present embodiment, as shown in FIG. 6B, the detection unit 130 is provided at a position corresponding to the predetermined portion 136 of the secondary battery 124. Here, since the secondary battery 124 is not yet deformed, the detection unit 130 does not react at all.

  The secondary battery 124 expands by repeated charging, and in particular, deformation may occur in the predetermined portion 136. As shown in FIG. 6C, when a predetermined amount of deformation occurs, the detection unit 130 is pressed to detect the deformation, and the process change unit 132 operates. The process changing unit 132 changes the charging process of the charging circuit 128, and the deformation of the secondary battery 124 is stopped. However, since the deformed secondary battery 124 does not return to its original state because the charging process is changed, the detection unit 130 continues to detect a predetermined amount of deformation unless the secondary battery 124 is replaced. .

  FIG. 7 is a cross-sectional view of FIG. 2A-A for explaining another example of the detection unit. Here, as shown in FIG. 7A, the detection unit includes a metal 182 provided on the surface of the predetermined portion 136 of the secondary battery 124 and a metal 184 provided on the fixed portion 126 side.

  A slight current is constantly applied to the metal 184 provided on the fixed portion 126 side, and the electrical resistance between the metals is measured. In the state of FIG. 7A in which the secondary battery 124 is not expanded, a very high electric resistance value is shown. Then, as shown in FIG. 7B, when the metal 182 provided in the secondary battery 124 comes into contact with the two metals 184 on the fixed portion 126 side, the two metals 184 on the fixed portion 126 side become conductive, The metal resistance becomes 0 (zero). By such a change in electrical resistance, the detection unit can detect a predetermined amount of deformation.

  FIG. 8 is a cross-sectional view of FIG. 2A-A for explaining still another example of the detection unit. Here, as shown in FIG. 8A, the detection unit includes a light emitting unit 190, a reflecting unit 192 that is provided in a predetermined portion 136 of the secondary battery 124 and reflects light from the light emitting unit 190, and reflected light. And a light receiving portion 194 for receiving light.

  The light emitting unit 190 emits light toward the reflecting unit 192, the reflecting unit 192 reflects the light, and the light receiving unit 194 receives the light reflected by the reflecting unit 192. The detection unit measures and holds the amount of light received by the light receiving unit 194 in such a state. When the secondary battery 124 is deformed as shown in FIG. 8B, the distances between the light emitting unit 190 and the light receiving unit 194 and the reflecting unit 192 are shortened, and the amount of light received by the light receiving unit 194 changes. If the amount of received light exceeds a predetermined value, it is determined that the deformation is a predetermined amount.

  FIG. 9 is a cross-sectional view of FIG. 2A-A for explaining still another example of the detection unit. Here, the detection unit includes a light emitting unit 196 and a light receiving unit 198 disposed at a position where an optical path from the light emitting unit 196 is blocked by deformation of the secondary battery 124.

  The light emitted from the light emitting unit 196 is directly received by the light receiving unit 198. If the deformation amount of the predetermined portion 136 of the secondary battery 124 does not reach the predetermined amount as shown in FIG. 9A, the light emitted from the light emitting unit 196 continues to be received by the light receiving unit 198. However, as shown in FIG. 9B, if the light emitted from the light emitting unit 196 cannot be received by the light receiving unit 198, the amount of deformation of the predetermined portion 136 has reached the predetermined amount, and it is determined that the light is blocked. To do. Therefore, the detection unit detects that the deformation amount of the secondary battery 124 is a predetermined amount.

  FIG. 10 is an explanatory diagram for explaining the operation of the process changing unit 132, particularly the changing operation of the target voltage value. When the secondary battery 124 does not reach the predetermined amount, the detection unit 130 does not react at all, and the secondary battery 124 is charged when the terminal voltage reaches the target voltage value (charge) as shown in FIG. The process ends when the capacity reaches a predetermined amount.

  However, when the detection unit 130 detects a predetermined amount of deformation of the secondary battery 124, the target voltage value is set to a low setting as shown in FIG. For example, the process change unit 132 changes the target voltage value 4.2V before detection of the detection unit to 4.0V after detection. When the target voltage value is lowered, the final value of the terminal voltage is lowered. By reducing the charging time in a high voltage (for example, 4.2V) state of charge, the chemical reaction can be suppressed, and the terminal voltage can reach the target voltage value early, thereby shortening the charging time. . Therefore, the progress of the deformation amount of the secondary battery 124 can be suppressed.

  FIG. 11 is an explanatory diagram for explaining the operation of the process changing unit 132, particularly the changing operation of the stop current value. When the secondary battery 124 does not reach the predetermined amount, the detection unit 130 does not react at all, and the charging of the secondary battery 124 is performed when the charging current decreases to the stop current value as shown in FIG. End with.

  However, when the detection unit 130 detects a predetermined amount of deformation of the secondary battery 124, the stop current value is set to be higher as shown in FIG. For example, the process change unit 132 changes 5 mA, which is a stop current value before detection of the detection unit, to 20 mA after detection. If the stop current value is set high, the charging current reaches the stop current value early, and the charging time can be shortened. Therefore, the progress of the deformation amount of the secondary battery 124 can be suppressed.

  Further, the process changing unit 132 can forcibly stop charging or shorten the charging time. By stopping the charging and shortening the charging time, the charging of the secondary battery 124 itself is suppressed, so that the generation of heat can be remarkably suppressed, and the deformation amount of the secondary battery 124 can be stopped or alleviated.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used for an electronic device capable of detecting a deformation amount of a secondary battery.

It is the functional block diagram which showed the function of the portable terminal in this embodiment. It is an external appearance perspective view for demonstrating the schematic structure of the portable terminal in this embodiment. It is a perspective view for demonstrating the alerting | reporting process of the deformation | transformation of the secondary battery by the alerting | reporting part in this embodiment. It is an assembly drawing which shows fitting of the secondary battery of the portable terminal in this embodiment. It is sectional drawing before and behind a deformation | transformation of the secondary battery in this embodiment. It is FIG. 2A-A sectional drawing for demonstrating the detection part in this embodiment. It is FIG. 2A-A sectional drawing for demonstrating the other example of the detection part in this embodiment. FIG. 3 is a cross-sectional view of FIG. 2A-A for explaining still another example of the detection unit in the present embodiment. FIG. 3 is a cross-sectional view of FIG. 2A-A for explaining still another example of the detection unit in the present embodiment. It is target voltage value operation | movement of the process change part in this embodiment. It is stop current value operation | movement of the process change part in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Portable terminal 114 ... Display part 120 ... Audio | voice output part 124 ... Secondary battery 126 ... Fixed part 128 ... Charging circuit 130 ... Detection part 132 ... Process change part 134 ... Notification part 136 ... Predetermined part 170 ... Secondary battery protective cover 182, 184 ... Metal 190, 196 ... Light emitting part 192 ... Reflecting part 194, 198 ... Light receiving part

Claims (5)

A secondary battery,
A fixing part for fixing the secondary battery;
A charging circuit for charging the secondary battery;
A detection unit for detecting a predetermined amount of deformation in a predetermined part of the secondary battery;
A process changing unit that changes a charging process of the secondary battery by the charging circuit when the detection unit detects the predetermined amount of deformation during charging of the secondary battery;
Equipped with a,
The detection unit includes a light-emitting unit, a reflection unit that is provided at a predetermined portion of the secondary battery and reflects light from the light-emitting unit, and a light-receiving unit that receives the reflected light. An electronic apparatus , wherein a predetermined amount of deformation is detected by a change in the amount of received light due to deformation of a battery . A secondary battery,
A fixing part for fixing the secondary battery;
A charging circuit for charging the secondary battery;
A detection unit for detecting a predetermined amount of deformation in a predetermined part of the secondary battery;
A process changing unit that changes a charging process of the secondary battery by the charging circuit when the detection unit detects the predetermined amount of deformation during charging of the secondary battery;
Equipped with a,
The electronic device according to claim 1, wherein the detection unit includes a light emitting unit and a light receiving unit disposed at a position where an optical path from the light emitting unit is blocked by deformation of the secondary battery . If the process changing unit is functioning, the deformation of the secondary battery, characterized by further comprising an informing unit for informing that reaches a predetermined amount, the electronic device according to claim 1 or 2. The change of the charging process, characterized in that it is a stop of the charging, the electronic device according to any one of claims 1-3. The change of the charging process is a change of one or two or more values selected from a group of a target voltage value, a stop current value, and a charging time as a charging completion condition of the secondary battery. Item 4. The electronic device according to any one of Items 1 to 3 .

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