Drum type washing machine and drying method thereof

Abstract

A nonvolatile semiconductor memory device which is superior in writing and charge holding properties, including a semiconductor substrate in which a channel formation region is formed between a pair of impurity regions formed with an interval, and a first insulating layer, a floating gate, a second insulating layer, and a control gate over an upper layer portion of the semiconductor substrate. It is preferable that a band gap of a semiconductor material forming the floating gate be smaller than that of the semiconductor substrate. For example, it is preferable that the band gap of the semiconductor material forming the floating gate be smaller than that of the channel formation region in the semiconductor substrate by 0.1 eV or more. This is because, by decreasing the bottom energy level of a conduction band of the floating gate electrode to be lower than that of the channel formation region in the semiconductor substrate, carrier injecting and charge holding properties are improved.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a flowchart illustrating a drying cycle of a conventional drum type washing machine;

FIG. 2 is a sectional view illustrating a drum type washing machine according a preferred embodiment of the present invention;

FIG. 3 is a block diagram illustrating the drum type washing machine according to the preferred embodiment of the present invention;

FIG. 4 is a flowchart illustrating a drying cycle of a drum type washing machine according to a first preferred embodiment of the present invention;

FIGS. 5 and 6 are flowcharts illustrating respective drying cycles in FIG. 4;

FIG. 7 is a flowchart illustrating a drying cycle of a drum type washing machine according to a second preferred embodiment of the present invention;

FIGS. 8, 9, and 10 are flowcharts illustrating respective drying cycles in FIG. 6;

FIG. 11 is a graph illustrating the relation between temperature and time during the drying cycle of the drum type washing machine according to the second preferred embodiment of the present invention;

FIG. 12 is a graph illustrating the relation between temperature and time with respect to the quantity of laundry during the drying cycle of the drum type washing machine according to the second preferred embodiment of the present invention;

FIG. 13 is a flowchart illustrating a drying cycle of a drum type washing machine according to a third preferred embodiment of the present invention; and

FIG. 14 is a flowchart illustrating a drying cycle of a drum type washing machine according to a fourth preferred embodiment of the present invention.

Claims

1. A drum type washing machine comprising: a tub including a drum into which laundry is put;a drum motor for rotating the drum;a drying duct installed to communicate with the tub and to provide a path through which air, heated by a drying heater that is installed therein, flows;a blower installed at a side of the drying duct to supply air heated by the drying heater to the tub through the drying duct;a first temperature sensor installed in the drying duct to detect temperature of air to be supplied to the tub; anda microcomputer for dividing the temperature of air in the tub during a drying cycle into a first temperature range and a second temperature range, maintaining the temperature of air to be supplied to the tub within the first and second temperature ranges by controlling the drying heater during drying processes corresponding to the first and second temperature ranges, and controlling an RPM of the drum motor, when the first temperature sensor detects temperature of the drying duct.

2. The drum type washing machine as set forth in claim 1, further comprising a condenser for supplying condensing water to a wall of a condensing duct disposed between the tub and the blower to condense water vapor, in the wet condensing duct, formed during the drying cycle.

3. The drum type washing machine as set forth in claim 1, wherein the first temperature sensor is installed at a side of the tub.

4. The drum type washing machine as set forth in claim 1, further comprising: a second temperature sensor for detecting temperature in the tub and outputting the detected temperature to the microcomputer,wherein the second temperature sensor is installed is between the tub and the drum to control the RPM of the drum motor based on the temperature detected by the second temperature sensor.

5. A washing method of a drum type washing machine comprising the steps of: (1) detecting temperature of air in a tub including a drum and a drying duct communicating with the tub by a first temperature sensor when a drying mode is selected;(2) controlling a drying heater based on the temperature detected by the first temperature sensor to heat air in the drying duct within a first temperature range and to supply the heated air to the tub using a blower;(3) supplying condensing water to a wall of a condensing duct disposed between the tub and the blower to condense water vapor in the drying duct; and(4) controlling the drying heater based on the temperature detected by the first temperature sensor to heat air in the drying duct within a second temperature range such that the heated air is supplied to the tub by the blower.

6. The washing method of a drum type washing machine as set forth in claim 5, wherein the step (1) comprises the sub-step of measuring eccentricity of the drum and performing an detangling cycle when the measure eccentricity is equal to or greater than a predetermined reference eccentricity.

7. The washing method of a drum type washing machine as set forth in claim 5, wherein the step (2) comprises the sub-steps of: (a) driving a drum motor for rotating the drum within a first motor driving range; and(b) driving the drum motor for rotating the drum within a second motor driving range.

8. The washing method of a drum type washing machine as set forth in claim 7, wherein the step (1) further comprises the sub-steps of measuring the quantity of laundry when a completely drying mode is selected from the drying modes and the sub-step (a) is finished, and of estimating and displaying an expected remaining time of a drying cycle according to the measured quantity of laundry.

9. The washing method of a drum type washing machine as set forth in claim 7, wherein in the step (2), when temperature, detected by a second temperature sensor for detecting inner temperature of the tub, is equal to or greater than a reference temperature, only the sub-step (b) among the sub-steps (a) and (b) is carried out.

10. The washing method of a drum type washing machine as set forth in claim 9, wherein the reference temperature is 50 degrees centigrade.

11. The washing method of a drum type washing machine as set forth in claim 9, wherein in the step (2), a slope with respect to temperature change in the tub, which is detected by the second temperature sensor for detecting the inner temperature of the tub, is estimated, and when the detected slope is equal to or greater than a predetermined reference slope, the step (3) is carried out.

12. The washing method of a drum type washing machine as set forth in claim 9, wherein the sub-steps (a) and (b) are carried out for a predetermined time within the first motor driving range and the second motor driving range, respectively.

13. The washing method of a drum type washing machine as set forth in claim 11, wherein the predetermined time is 20 minutes.

14. The washing method of a drum type washing machine as set forth in claim 11, wherein the first motor driving range is 1000 RPM to 1200 RPM.

15. The washing method of a drum type washing machine as set forth in claim 11, wherein the second motor driving range is 40 RPM to 60 RPM.

16. The washing method of a drum type washing machine as set forth in claim 11, wherein the first temperature range is 110 degrees centigrade to 120 degrees centigrade.

17. The washing method of a drum type washing machine as set forth in claim 11, wherein the second temperature range is 95 degrees centigrade to 105 degrees centigrade.

18. A washing method of a drum type washing machine comprising the steps of: (1) detecting temperature in a tub by a second temperature sensor for detecting the temperature in the tub when a drying mode is selected;(2) rotating a drum within a first motor driving range for a first predetermined time by a drum motor for rotating the drum when temperature detected by the second temperature sensor is less than a reference temperature, and of rotating the drum motor within a second motor driving range after that and heating and supplying air in a drying duct within a first temperature range by a drying heater and a blower which are installed in the drying duct communicated with the tub for a second predetermined time;(3) supplying condensing water to a wall of a condensing duct disposed between the tub and the blower to condense water vapor in the drying duct, when the second predetermined time has elapsed; and(4) rotating the drum within the first motor driving range by the drum motor for the first predetermined time when the second predetermined time has elapsed, and of rotating the drum motor within the second motor driving range and heating and supplying air in the drying duct by the drying heater and the blower for the second predetermined time.

19. The washing method of a drum type washing machine as set forth in claim 18, wherein when the temperature, detected by the second temperature sensor for detecting inner temperature of the tub, is equal to or greater than a reference temperature, only step (4) is carried out.

20. The washing method of a drum type washing machine as set forth in claim 19, wherein the reference temperature is 50 degrees centigrade.

21. The washing method of a drum type washing machine as set forth in claim 18, wherein the first predetermined time is 10 minutes.

22. The washing method of a drum type washing machine as set forth in claim 18, wherein the second predetermined time is 40 minutes.

23. The washing method of a drum type washing machine as set forth in claim 18, wherein the first motor driving range is 1000 RPM to 1200 RPM.

24. The washing method of a drum type washing machine as set forth in claim 18, wherein the second motor driving range is 40 RPM to 60 RPM.

25. The washing method of a drum type washing machine as set forth in claim 18, wherein the first temperature range is 110 degrees centigrade to 120 degrees centigrade.

26. The washing method of a drum type washing machine as set forth in claim 18, wherein the second temperature range is 95 degrees centigrade to 105 degrees centigrade.

27. The washing method of a drum type washing machine as set forth in claim 19, wherein in the step (2), the drum motor is driven at an allowable maximal RPM of the drum type washing machine.