Vacuum cleaner

1. A vacuum cleaner, comprising:

a housing comprising a bottom, a top and a side interconnecting the top and the bottom;

at least one bottom opening formed in the bottom of the housing;

a cavity formed in the housing in fluid communication with the at least one bottom opening;

an ultra violet light source configured to irradiate ultra violet light to a surface under the bottom;

a hitting duster configured to beat the surface under the bottom;

means for forcing air in a direction within the housing to form a negative pressure in the cavity such that an air flow can be made through the at least one bottom opening from outside the housing to the cavity during operation of the vacuum cleaner;

at least one auxiliary opening formed on at least one of the side and the top, wherein the at least one auxiliary opening is also in fluid communication with the cavity such that a substantial air flow is made through the at least one auxiliary opening from outside the housing to the cavity as a negative pressure is formed in the cavity, even if the at least one bottom opening is completely blocked during operation of the vacuum cleaner; and

wherein the at least one auxiliary opening is provided by a plurality of ribs formed on the at least one of the side and the top of the housing.

2. The vacuum cleaner of claim 1 , wherein the plurality of ribs further provide at least one air flow channel to connect to the cavity.

3. The vacuum cleaner of claim 1 , wherein the top and the side of the housing do not have a discrete boundary therebetween.

4. The vacuum cleaner of claim 1 , wherein the substantial air flow from the at least one auxiliary opening to the cavity is to prevent the negative pressure created in the cavity from being excessive.

5. The vacuum cleaner of claim 1 , wherein the hitting duster comprises a head configured to make repeated movements to the surface and back to the housing through a hitting duster opening formed in the bottom of the housing.

6. The vacuum cleaner of claim 5 , wherein the hitting duster further comprises an actuator connected to the head and configured to actuate the movements of the head.

7. The vacuum cleaner of claim 1 , further comprises:

a first filter located at a first position within the suction passage and configured to filter air flowing through the suction passage; and

a second filter located at a second position within the suction passage downstream the first position and configured to further filter the air flowing through the suction passage past the first filter.

8. The vacuum cleaner of claim 1 , further comprising a heater configured to heat air being transferred through the suction passage.

9. The vacuum cleaner of claim 1 , further comprising:

a suction passage formed in the housing and in fluid communication with the cavity so as to create a negative pressure in the cavity during operation of the vacuum cleaner, wherein the at least one bottom opening is configured to suck outside dust into the cavity when a negative pressure is created in the cavity.

10. The vacuum cleaner of claim 9 , wherein the suction passage comprises an inlet open to the cavity.

11. The vacuum cleaner of claim 9 , further comprising an ultra violet light source configured to irradiate ultra violet light to air being transferred through the suction passage.

12. A method of vacuum cleaning, comprising:

providing a vacuum cleaner comprising:

a housing comprising a bottom, a top and a side interconnecting the top and the bottom,

at least one bottom opening formed in the bottom of the housing;

a cavity formed in the housing in fluid communication with the at least one bottom opening,

an ultra violet light source configured to irradiate ultra violet light to a surface under the bottom,

a hitting duster configured to beat the surface under the bottom,

means for forcing air in a direction within the housing to form a negative pressure in the cavity such that an air flow can be made through the at least one bottom opening from outside the housing to the cavity during operation of the vacuum cleaner, and

at least one auxiliary opening formed on at least one of the side and the top, wherein the at least one auxiliary opening is also in fluid communication with the cavity such that a substantial air flow is made through the at least one auxiliary opening from outside the housing to the cavity as a negative pressure is formed in the cavity, even if the at least one bottom opening is completely blocked during operation of the vacuum cleaner,

wherein the at least auxiliary opening is provided by a plurality of ribs formed on the at least one of the side and the top of the housing;

placing the vacuum cleaner over a surface such that the bottom faces the surface to clean; and

operating the vacuum cleaner so as to create a negative pressure in the cavity, thereby sucking dust and particles into the cavity from the surface via the at least one bottom opening, and thereby creating a substantial air flow into the cavity via the at least one auxiliary opening.

13. The method of claim 12 , wherein the surface comprises a mattress surface or a bedding surface made of a fabric.

14. The method of claim 12 , wherein the method further comprise irradiating ultra violet light onto the surface during the operation.

15. The method of claim 12 , wherein the substantial air flow from the at least one auxiliary opening to the cavity is to prevent the negative pressure created in the cavity from being excessive.

16. The method of claim 12 , wherein the housing comprises a plurality of ribs arranged so as to provide the at least one auxiliary opening.

17. The method of claim 12 , wherein the vacuum cleaner further comprises a suction passage formed in the housing and in fluid communication with the cavity so as to create a negative pressure in the cavity during operation of the vacuum cleaner, wherein the at least one bottom opening is configured to suck outside dust into the cavity when a negative pressure is created in the cavity, wherein the suction passage comprises an inlet open to the cavity.