Dryer and method for controlling the same

A dryer is disclosed. The dryer includes dryer includes a door opening sensing unit sensing an opening of a door, a heater heating air provided in a drum, and a microcomputer determining an error in the heater based on an internal temperature condition of the drum, which changes in accordance with a driving time of the heater, and setting a new driving time of the heater, when the door is open before the driving time of the heater being counted reaches a predetermined driving time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Application Nos. P2003-059061, filed on Aug. 26, 2003, and P2003-059062, filed on Aug. 26, 2003, which are hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dryer, and more particularly, to a dryer and a method for controlling the same. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for controlling the dryer when a door thereof is open and when a drum thereof comes into physical contact with a user.

2. Discussion of the Related Art

A dryer is a machine for drying damp washed clothes by using heated air. A structure of a general dryer will now be described in detail. Referring toFIG. 1, a drum2is fixed within a case1, and an opening3for inputting washed clothes into the drum2is formed on a front surface of the case1. A door4that can be opened and closed is fixed to the opening3.

A motor5for rotating the drum2is formed on an upper portion inside the case1. The motor5transmits a rotating force to the drum2through a belt6for drums. A plurality of wings7is formed on an inner wall of the drum2so as to stir the washed clothes when the drum2is rotated. A circulation duct8for circulating the air within the drum2is formed below the drum2. And, in order to provide hot air to the drum2, a heater11for heating air is provided between the drum2and the circulation duct8. A fan9for exhausting the air within the drum2is formed behind the drum2. The fan9rotates by receiving a driving force from the motor5through the belt10. A supply duct11supplying ambient air to the circulation duct8and a condensed water discharge duct13for discharging condensed water, which is produced during the circulation of the air, to the outside are connected to the circulation duct8.

When the door4is open during the drying cycle, ambient air is flown into the drum2, and after the door4is closed, the dryer resumes the drying cycle. At this point, the temperature condition inside the drum2is abruptly changed, thereby preventing the washed clothes from being completely dried. Also, in case of large capacity dryers, when a child puts himself or herself inside the drum, the dryer cannot sense the presence of the child, which may result in accidents caused by carelessness.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a dryer and a method for controlling the same that can reset a driving time of the heater, when the door of the dryer is open during a drying cycle, while taking various external factors into consideration.

Another object of the present invention is to provide a dryer and a method for controlling the same that can prevent accidents caused by carelessness.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a dryer includes a door opening sensing unit sensing an opening of a door, a heater heating air provided in a drum, and a microcomputer determining an error in the heater based on an internal temperature condition of the drum, which changes in accordance with a driving time of the heater, and setting a new driving time of the heater, when the door is open before the driving time of the heater being counted reaches a predetermined driving time.

Herein, the microcomputer provides an alarm or a message to a user, so as to inform the user of an error occurring in the heater, and the microcomputer sets a new driving time of the heater based on the counted driving time of the heater. Also, the microcomputer either sets a new driving time of the heater based on an internal temperature condition of the drum, or compares the internal temperature condition of the drum with a plurality of reference internal temperature conditions and sets a new driving time of the heater based on the compared value.

In another aspect of the present invention, a method for controlling a dryer includes initially setting a driving time of a heater, the heater heating air provided in a drum, sensing whether a door of the dryer is open during the initially set driving time, and setting a new driving time of the heater, if the door of the dryer is open during the initially set driving time, and determining whether an error is occurring based on an internal temperature condition, which changes in accordance with the driving time of the heater.

Herein, the initially setting a driving time of a heater includes initially setting a driving time of the heater in accordance with an amount or a type of clothes to be dried.

Also, the setting a new driving time of the heater includes setting a new driving time of the heater in accordance with an internal temperature condition of the drum. Moreover, the setting a new driving time of the heater in accordance with an internal temperature condition of the drum includes comparing the internal temperature condition of the drum with a plurality of reference temperature conditions, and setting a new driving time of the heater in accordance with the compared result.

The setting a new driving time of the heater includes setting a new driving time of the heater in accordance with a processed driving time of the heater.

In another aspect of the present invention, a dryer includes a heater heating air provided in a drum, a sensor sensing whether a human body is in physical contact with a drum, and a microcomputer stopping a driving of the heater and a rotation of the drum, when the human body comes into physical contact with the drum.

Herein, the sensor senses a change in electrostatic capacity of the drum.

The microcomputer outputs an alarm or a warning message and opens a door of the dryer, when the human body comes into physical contact with the drum. At this point, the microcomputer also discharges air within the drum.

In a further aspect of the present invention, a method for controlling a dryer includes sensing whether a human body comes into physical contact with a drum, and stopping a driving of the heater and a rotation of the drum, when the human body comes into physical contact with the drum.

The method for controlling the dryer further includes opening a door of the dryer and discharging air within the drum, when the human body comes into physical contact with the drum.

Herein, the sensing whether a human body comes into physical contact with a drum includes detecting a changed amount of electrostatic capacity of the drum, comparing the detected changed amount of electrostatic capacity with a reference changed amount, and determining whether the human body comes into physical contact with the drum depending upon the compared result.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

FIG. 2illustrates a block diagram showing the structure of a dryer according to a first embodiment of the present invention. Referring toFIG. 2, the dryer according to the present invention includes a key input unit100for inputting user command, a motor400for rotating a drum, a heater500for heating air provided in the drum, a load driving unit600for driving the motor400and the heater500according to the user command, a door opening sensing unit200for sensing the door (numeral4ofFIG. 1) of the dryer being open, a microcomputer300resetting the driving time of the heater500, when the door opening sensing unit200senses the door being open, and re-counting the time, an error display unit700displaying any error occurring in a unit of the dryer, such as the heater, in accordance with the control of the microcomputer300, and a temperature sensing unit800sensing the temperature condition within the drum (numeral2ofFIG. 1) of the dryer.

The method for controlling the dryer according to the present invention will now be described in detail. The user selects a course or an option for drying washed clothes through the key input unit100, for example, a driving time of the heater500depending upon the amount or type of the washed clothes, or a heating level of the heater500. Alternatively, the microcomputer300can automatically set up driving time of the heater500and the heating level of the heater500depending upon the amount or type of the washed clothes to be dried. Also, when the user inputs a “start” command, the microcomputer300drives the motor400and the heater500in accordance with the selected course or option (S101to S103).

When the heater500is driven, the microcomputer300begins to count the driving time of the heater500and periodically determines as to whether the driving time being counted is equal to a predetermined driving time of the motor500(S104). If the door is open before the driving time being counted reaches the predetermined driving time (S105), then the microcomputer300stops the driving of the heater500and sets up a new driving time of the heater500(S106). When the door opens during the drying cycle, the temperature condition within the drum may be decreased due to the inflow of ambient air. If the driving time of the heater500is not reset, then the damp clothes may not be completely dried and the controller (or microcomputer)300may determine that an error has occurred in the heater500. Therefore, the microcomputer300sets up a new driving time of the heater500depending upon the previously counted driving time or the measured temperature condition within the drum. More specifically, if the previously counted driving time is long, then the newly set driving time is relatively shorter, and if the previously counted driving time is short, then the newly set driving time is relatively longer. Additionally, if the measured temperature condition within the drum is high, then the new driving time of the heater500is set to be short, and if the measured temperature condition within the drum is low, then the new driving time of the heater500is set to be long. Evidently, the newly set driving time of the heater500can also be decided in accordance with a comparison result after comparing the temperature condition within the drum with reference temperatures. Accordingly, the microcomputer300restarts the driving of the heater500for a newly set driving time, and the counting of the driving time of the heater500is also restarted.

The temperature sensing unit800constantly senses the internal temperature condition of the drum. The microcomputer300determined the error in the heater500based on the change in the internal temperature condition of the drum as the driving time of the heater500is being processed (S107). For example, when the internal temperature condition of the drum is lower than the predetermined temperature by the time the driving time of the heater500reaches the predetermined driving time, the microcomputer300determines that an error has occurred in the heater500(S110). Then, the microcomputer300either displays a message on the error display unit700or sets off an alarm in order to notify the user of the error in the heater500(S111). On the other hand, when the internal temperature condition of the drum reaches the predetermined temperature level, the microcomputer300determines that the heater500is operating normally and ends the drying cycle.

Second Embodiment

FIG. 4illustrates a block diagram showing the structure of a dryer according to a second embodiment of the present invention. Referring toFIG. 4, the dryer includes a key input unit110for inputting user command, a motor510for rotating a drum, a heater610for heating air provided in the drum, a sensor210for sensing physical contact of the drum with a human body, a microcomputer310stopping the rotation of the motor510and the driving of the heater610, when the sensor210senses a human body being in physical contact with the drum, and a load driving unit410for driving the motor510and the heater610according to the controls of the microcomputer310.

The sensor210is an electrostatic capacity detecting sensor detecting the amount of electrostatic capacity of the drum, which is mounted on an inner wall of the drum. The drum is formed of a metal, such as aluminum, and so, the sensor210can sense a human body physically contacting the drum based on a change in the electrostatic capacity of the drum. The microcomputer310verifies a changed amount of electrostatic capacity of the drum from the sensor210and, then, compares the changed amount of electrostatic capacity with a reference amount of electrostatic capacity. If the changed amount of the electrostatic capacity exceeds the reference changed amount, the microcomputer310determined that a human body is in physical contact with the drum.

A method for controlling the dryer according to the second embodiment of the present invention will now be described in detail.FIG. 5illustrates a flow chart showing the process steps of the method for controlling the dryer in accordance with the second embodiment of the present invention. Referring toFIG. 5, a user turns on the dryer (S201), and then the user selects a course or an option for drying washed clothes through the key input unit110, for example, a driving time of the heater610depending upon the amount or type of the washed clothes, or a heating level of the heater610. Alternatively, the microcomputer310can automatically set up driving time of the heater610and the heating level of the heater610depending upon the amount or type of the washed clothes to be dried. Also, when the user inputs a “start” command (S202), the microcomputer310drives the motor510and the heater610in accordance with the selected course or option.

When the dryer is turned on, the sensor210senses whether a human body is in physical contact with the drum. If there is no physical contact in the drum, the microcomputer310drives the motor510and the heater610in accordance with the selected course or option, thereby performing the drying cycle. Also, the senor210sense whether a human body is in physical contact with the drum, even while the drying course is in process (S203).

If a physical contact with a human body occurs during the drying cycle (S204), the microcomputer310controls the load driving unit410, so as to stop the driving of the motor510and the heater610. Accordingly, the load driving unit410shuts down the power supplied to the motor510and the heater610based on the control of the microcomputer310(S205). Then, the microcomputer310opens the door in order to discharge the heated air within the drum to the outside of the dryer. Thereafter, the microcomputer310sets off an alarm or displays a warning message on a display unit (not shown).

On the other hand, if a physical contact with a human, body does not occur during the drying cycle, the microcomputer310drives the motor510and the heater610normally. Nevertheless, the microcomputer310constantly verifies whether the drum comes into a physical contact with a human body at any random time during the course of the drying cycle.

As described above, the dryer according to the present invention has the following advantages.

By resetting a driving time of a heater when the door of the dryer is open during the course of a drying cycle, the drying efficiency for damp washed clothes that are to be dried can be enhanced. Also, by sensing the internal temperature condition of the drum, a microcomputer can accurately control the operation of the heater in accordance with the change in the temperature conditions. Finally, the dryer according to the present invention can detect any physical contact of the drum with a human body, thereby preventing accidents caused by carelessness.