WO2010018391A2

WO2010018391A2 - Sensor cleaning device

Info

Publication number: WO2010018391A2
Application number: PCT/GB2009/050755
Authority: WO
Inventors: Daniel Kane
Original assignee: Meso Limited
Priority date: 2008-08-14
Filing date: 2009-06-29
Publication date: 2010-02-18
Also published as: WO2010018391A3; GB0814842D0; GB201102692D0; GB2474992A

Abstract

There is herein described a device and a method for removing contamination from sensor surfaces. Moreparticularly, there is described a device and a method for removing dust contamination from electronic sensors found in, for example, camera equipment.

Description

SENSOR CLEANING DEVICE

FIELD OF THE INVENTION

The present invention relates to a device and a method for removing contamination from sensor surfaces. More particularly, the present invention relates to a device and a method for removing dust contamination from electronic sensors found in, for example, camera equipment.

BACKGROUND OF THE INVENTION

Dust has always been a problem for photographers and remains so even today. Any contamination on an image sensor of a digital camera will yield dark patches in the resulting shots. This problem is increased significantly in the case of Digital Single Lens Reflex (DSLR) photography. Unlike compact digital cameras, the image sensor in DSLR's is not permanently sealed within the unit due to the ability to interchange the lens. This coupled with the significantly larger image sensor means that sensor dust is an inevitability for any DSLR owner. As DSLR's lie at the more professional end of the photography market the quality of photograph taken is likely to be of high importance. For professional photographers, post processing to digitally remove spots, can be an extremely time consuming and ultimately costly operation. Unfortunately, removing contamination from Charged Couple Device (CCD) sensors is not an easy process. Moreover, the CCD sensors are sensitive to excess pressure and there is a risk during cleaning of dragging aggressive particles over the delicate optical glass sensor covering, resulting in an expensive repair.

A large proportion of DSLR owners are not willing to clean their own sensors due to the perceived risks involved. Therefore, owners have to send their cameras to be professionally cleaned. This process can cost anywhere between £50 - £100 and take up to two weeks. This option is at best inconvenient and in some situations not possible. For example, take the position of a wildlife photographer in Kenya or a photo journalist in the Middle East, where it would be very difficult to have their camera professionally cleaned.

Photographic based manufacturers have recognised this dust problem and are attempting to introduce preventative measures in the form of ultrasonic shakers attached to sensor housings. This mechanism is designed to try and shake off dust from the sensor when a camera is powered up. While it does have some success in prolonging the time between cleaning, it is still inevitable that a user will have to manually clean the image sensor. The ultrasonic shaker also has some further drawbacks:

• Tests have shown that particle removal is at best 50% even after 25 cycles;

• The ultrasonic shaker slows down power up time by a few seconds which could be extremely precious in some cases and lead to a professional photographer missing an important shot;

• The ultrasonic shaker does not tackle welded on particles and therefore is only capable of removing loose dust; and

• In dusty environments, a tape in the ultrasonic shaker that traps shaken off dust becomes quickly clogged meaning that contamination remains in the chamber.

There are other alternative methods for removing dust contamination from electronic sensors. However, these alternative methods also have significant disadvantages as shown below:

• Air Blowers - do not remove attached dust and can actually cause more dust to settle on the sensor;

• Sensor Swabs - it is not possible to transport methanol via air and it is also difficult to apply fluid to swab;

• Dust Aid - is time consuming in operation and it is difficult to know whether the whole sensor has been covered; and

• Sensor Brushes - it is difficult to remove contamination from a brush after use and it is also expensive for good quality brushes.

It is an object of at least one aspect of the present invention to obviate or mitigate at least one or more of the aforementioned problems.

It is a further object of at least one aspect of the present invention to provide an improved device and/or method for removing dust contamination from DSLR Charged Couple Device Sensors (CCD) that significantly reduces the risk of damage during the dust removal process.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a sensor cleaning device comprising: a cleaning mechanism comprising at least one cleaning pad; said cleaning mechanism comprising deployment means to position the at least one cleaning pad in a first configuration wherein the at least one cleaning pad is in a stored position and a second configuration wherein the at least one cleaning pad is capable of engaging with a surface of a sensor to be cleaned.

The present invention relates to the provision of a sensor cleaning device which allows a user to remove contamination from a sensor surface in a reliable, quick and risk free manner. The sensor may, for example, be a Charged Couple Device (CCD) sensor in a Digital Single Lens Reflex (DSLR) camera.

The cleaning mechanism may be located within a main body of the sensor cleaning device and comprises deployment means to position the at least one cleaning pad in a first configuration wherein the at least one cleaning pad may be in a stored (i.e. retracted) position and a second configuration wherein the at least one cleaning pad may be in an active position and capable of engaging with a surface of the sensor to be cleaned. The cleaning mechanism may therefore be used for removing dust contamination from, for example, electronic sensors located in camera equipment.

The at least one cleaning pad may be mounted on cleaning arms which may be spring mounted. In the first configuration, the cleaning arms may be separated from one another. In the second configuration, the cleaning arms may be substantially adjacent to one another.

The cleaning mechanism comprising the cleaning arms may be spring activated so that the at least one cleaning pad may be biased into the first configuration which is the stored (i.e. retracted) position. The cleaning mechanism may therefore naturally return to the first configuration from the second configuration.

The cleaning mechanism may comprise any suitable number of cleaning pads such as, for example, two cleaning pads mounted on the cleaning arms.

Typically, the cleaning mechanism may comprise an activation means for activating the cleaning mechanism. The activation means may operate the cleaning mechanism in a single motion. In particular embodiments, the activation means may be a collar located around the main body of the sensor cleaning device. The cleaning process may therefore involve a user pulling the activation means (e.g. the collar) substantially down, forcing the cleaning pads to substantially lower and rotate into the correct position (i.e. the second configuration) where they engage the surface of the sensor to be cleaned. During this process, the cleaning arms may move towards one another. Once the cleaning process is complete, the activation means (e.g. the collar) may spring back or may be lifted to return the cleaning pads to their original position. This process may be aided via a spring arrangement.

To remove contamination from the cleaning pads collected from a sensor in, for example, a camera, the cleaning action operated by the activation means may be repeated with a base cap attached to the sensor cleaning device. The base cap may house adhesive pads capable of engaging with and removing contamination from the at least one cleaning pad. Therefore, when the cleaning pads are saturated with contamination, the cleaning pads on contacting the adhesive pads may transfer the contamination to the adhesive pads. The adhesive pads may be provided in a single or multi-layer arrangement so that the top layer may be easily pealed away to reveal the next fresh adhesive leaf which can perform further cleaning operations on the cleaning pads. The adhesive pads may therefore be replaced by removing an adhesive sheet on the top of the adhesive pad. The adhesive pad may comprise about 50 adhesive strips that may be replaced. This step may be performed as many times as necessary. Typically, the cleaning pads may perform about twenty cleaning operations before they are required to be purged of any contaminants using the adhesive pads. The adhesive pads may therefore be pre-sheeted meaning that when the adhesive pad needs to be renewed, a used sheet may be quickly and easily removed exposing a new sheet underneath.

The cleaning device may also comprise a top casing. The top casing may comprise means to enable a user to view a sensor before and after the cleaning process. For example, the top casing may comprise a magnifying lens arrangement which may be illuminated to allow viewing of the sensor to occur. Illumination may be provided by LEDs or any other suitable means.

The cleaning pads may be made from or comprise any elastomeric material suitable for cleaning a surface of a sensor. The cleaning pads may therefore be designed to effectively pick up dry particles such as contaminants (e.g. dust particles) from a surface of a sensor. Typically, the cleaning surfaces of the cleaning pads are smooth. The cleaning pads may be elastomer cleaning pads and may be designed to pick up particles of about 0.4 μm to about 40 μm. It is desired that at least about 50%, 60%, 70%, 80%, or preferably at least about 90% or most preferably at least about 95% of relevant contamination may be removed with a single pass of the cleaning pads. Preferably, the cleaning elastomer pads may be reusable unlike many of the competing technologies. The cleaning pads may also be provided in a variety of sizes to accommodate substantially all camera types and sizes.

The sensor cleaning device according to the present invention has a number of advantages. For example, the system is reliable as it takes away the requirement to use a human to perform the actual cleaning. The sensor cleaning device may also be fitted to most camera mounts providing a stable datum from which to clean, with no risk of excess pressure being applied to the sensor. The sensor cleaning device also provides a sheltered environment to avoid further contamination during cleaning. The sensor cleaning device also does not leave behind any form of residue once the cleaning process is complete as it is a dry cleaning process.

According to a second aspect of the present invention there is provided a method for cleaning a sensor, said method comprising: providing a cleaning mechanism comprising at least one cleaning pad; providing deployment means to position the at least one cleaning pad in a first configuration wherein the at least one cleaning pad is in a stored position and a second configuration wherein the at least one cleaning pad is capable of engaging with a surface of a sensor to be cleaned.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a representation of a cleaning device according to an embodiment of the present invention;

Figure 2 is an exploded view of component parts of the cleaning device shown in Figure 1 ;

Figure 3 is a representation of the cleaning device shown in Figures 1 and 2 with a cap unscrewed;

Figure 4 is a representation of a top casing of the cleaning device shown in Figures 1 to 3;

Figure 5 is an exploded view showing component parts of the top casing shown in Figure 4;

Figures 6a - 6d are representations of the cleaning device shown in Figures 1 to 5 in operation; Figures 7 a - 7c are sectional views of the cleaning device shown in Figures 1 to 6d in operation;

Figures 8a - 8b are schematic representations of part the cleaning device shown in Figures 1 to 7c in operation;

Figures 9a - 9c are top views of the cleaning device shown in Figures 1 to 8b in operation; and

Figure 10 is a view of a circuit diagram used to power the cleaning device shown in Figures 1 to 9c.

BRIEF DESCRIPTION

Figure 1 is a representation of a cleaning device according to the present invention, the cleaning device is generally designated 100. The cleaning device 100 comprises: a main body 110; a base cap 112; and a top casing 114. The top casing 114 may attach to the main body 110 of the cleaning device 100 via a snap-fit arrangement and the base cap 112 may attach to the main body 110 of the cleaning device 100 via a screw-type arrangement.

Figure 2 is an exploded view of component parts of the cleaning device 100. The main body 110 has a central casing 116 which houses a cleaning mechanism for removing dust contamination from, for example, electronic sensors located in camera equipment. Figure 2 also shows that the base cap 112 comprises: a lower case 118; an adhesive pad connector ring 120; and an adhesive pad holder 122. Adhesive pads (not shown) may be located in the adhesive pad holder 122. Above the central casing 116 there is a collar 124. A collar grip 126 is connected around the collar 124. As will be shown below, the collar 124 can be used to activate the cleaning mechanism. There is also an LED holder 128 and a switch 130 for operating LEDs. The LEDs may be used to illuminate a sensor being cleaned which therefore allows a user to determine the level of dust contamination on the sensor before and after cleaning. A coin battery 125 may be held within a coin battery holder 127 and may be used to power the LEDs.

Figure 2 also shows that the top casing 114 comprises: an upper case 132; a lens mount 134; a lens 138; and upper and lower lens protectors 138,140, respectively. The lens mount 134, lens 138, and upper and lower lens protectors 138,140 are connected to the lens mount 134 via a series of screws 142. A user may therefore look through the top casing 114 to see the sensor being cleaned and therefore determine the level of contamination. On both sides of the cleaning device 100 shown in Figure 2, there is the mechanism which performs the cleaning operation. Each side of the cleaning mechanism is a mirror image of the other side. There are sliders 144, 146 which each have two protruding members 148,150, 152,154. The sliders 144,146 are important components within the cleaning device 100 and are responsible for constraining rotation in cleaning arms 158,160 during the mechanism deployment. The cleaning arms 158,160 each comprise two supporting members 162,164,166,168 which are used to support pivot rods 170,172 which themselves are connected to pivot springs 176,178. Figure 2 also shows pads 180,182 which are attached to cleaning pads 184,186.

The cleaning pads 184,186 are made from or comprise any elastomeric material suitable for cleaning a surface of, for example, camera CCD sensors. For example the cleaning pads 184,186 may be made from any suitable elastomer. The cleaning pads 184,186 are therefore designed to effectively pick up contamination including dry particles either stuck to or residing on a surface of a sensor. In particular, the cleaning pads 184,186 are designed to pick up particles of about 0.1 μm to 40 μm. It is desired that at least about 90% of relevant contamination is removed with a single pass of the cleaning pads 184,186.

As shown in Figure 3, the cap 112 may be screwed off the main body 110 allowing a cleaning process on a sensor to occur. The cleaning process is discussed in more detail below.

Figure 4 is an expanded view of the top casing 114. The top casing 114 contains electrical components responsible for illuminating a sensor to check for particles of contamination. Figure 5 shows the components of the top casing 114: the coin battery 125; the coin battery holder 127; the LED holder 128; the switch 130; and the upper case 132.

Figures 6a - 6d show the cleaning device 100 in operation. In Figure 6a, the base cap 112 is still attached to the main body 110 of the cleaning device 100. The base cap 112 serves a dual purpose: to seal the cleaning device 100 when not in use; and to hold adhesive pads which may be used to purge the cleaning pads 184,186 of contamination. In Figure 6b, the base cap 112 has been screwed off the main body 110 of the cleaning device 100. Once the base cap 112 has been screwed off, a camera mount attachment may then be added to the device 100 depending on the DSLR model. This serves two purposes: to secure the device 100 to a camera 200; and to use the level as a datum in order to lower cleaning pads 184,186 to exactly the correct distance within the camera body to contact and clean the sensor.

The cleaning process is shown in Figure 6c. To initiate the cleaning process, a user simply pulls the collar 124 down, forcing the cleaning pads 184,186 to lower and rotate into the correct position and engage with a sensor 196 to be cleaned. Once the cleaning process is complete, the collar 124 is lifted or may spring back to return to the original position. When the cleaning pads 184,186 are in the stored (i.e. retracted) position, a clear view of the sensor is available via the illuminated viewing port of the top casing 114 using the LEDs.

Figure 6d shows that to remove contamination on the cleaning pads 184,186 collected from the sensor 196 in the camera 200, the cleaning action is repeated with the base cap 112 replaced. When the cleaning pads 184,186 are saturated with contamination, the cleaning pads 184,186 on contacting the adhesive pads transfer the contamination to the adhesive pads. The adhesive pads are provided in a multi-layer arrangement so that the top layer is easily pealed away to reveal the next fresh adhesive leaf which can perform further cleaning operations on the cleaning pads 184,186.

Figures 7a - 7c are further views of the cleaning device 100 in operation. Figure 7a shows the cleaning pads 184,186 in a stored (i.e. retracted) position. In Figure 7a, the base cap 112 is attached and the adhesive pad holder 122 is shown. As a downward force is applied to the collar 124, the cleaning arms 158,160 as shown in Figure 7b are forced together with the result that the cleaning pads 184,186 are moved downwards towards a cleaning position. Figure 7c shows that as the collar 124 is forced down, the cleaning pads 184,186 are moved into the cleaning position where no gap is evident between the cleaning pads 184,186. Springs 188,190 in the cleaning arms 158,160 coupled with the pivot rods 170,172 attached to the cleaning pads 184,186 act as a return mechanism for the cleaning arms 158,160 to return to their original position.

Figure 8a is a schematic representation of the cleaning device 100 with the cleaning pads 184,186 in their stored (i.e. retracted) position. Figure 8b shows the cleaning pads 184,186 forced down on to adhesive pads 192 in the base cap 112 which are used to clean the cleaning pads 184,186 once they become dirty from the cleaning process.

Figures 9a - 9c are top views of the cleaning device 100 in operation. Figure 9a is when the collar 124 is in the initial position and the cleaning arms 158,160 are retracted leaving the sensor in full view. In Figure 10b, the sensor being cleaned is illuminated using LEDs to give a clear view of the sensor prior to cleaning. In Figure 9c, when cleaning arms 158,160 come together and the view of the sensor is obstructed, there is no need for the illumination to be turned on.

Figure 10 shows a lighting circuit suitable for operating the illumination of the LEDs in the top casing 114. The lighting circuit is extremely simple yet efficient, consisting of two LEDs in parallel each with a resistor to limit the current, a battery and a simple switch. The luminous intensity of each LED is 1.5cd giving the sensor sufficient illumination.

Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention. For example, any suitable type of mechanism may be used to lower the cleaning pads onto the sensor to be cleaned. Moreover, the cleaning pads may be made of any suitable elastomeric material and the adhesive pads used to decontaminate the cleaning pads may be provided in any appropriate form.

Claims

1. A sensor cleaning device comprising: a cleaning mechanism comprising at least one cleaning pad; said cleaning mechanism comprising deployment means to position the at least one cleaning pad in a first configuration wherein the at least one cleaning pad is in a stored position and a second configuration wherein the at least one cleaning pad is capable of engaging with a surface of a sensor to be cleaned.

2. A sensor cleaning device according to claim 1 , wherein the cleaning mechanism is located within a main body of the sensor cleaning device.

3. A sensor cleaning device according to any of claims 1 or 2, wherein the at least one cleaning pad is mounted on cleaning arms which are spring mounted.

4. A sensor cleaning device according to any preceding claim, wherein in the first configuration, the cleaning arms are separated from one another and in the second configuration, the cleaning arms are substantially adjacent to one another.

5. A sensor cleaning device according to any of claims 3 or 4, wherein the cleaning arms are spring activated so that the at least one cleaning pad is biased into the first configuration and the cleaning mechanism automatically returns to the first configuration from the second configuration.

6. A sensor cleaning device according to any preceding claim, wherein the cleaning mechanism comprises two cleaning pads mounted on cleaning arms.

7. A sensor cleaning device according to any preceding claim, wherein the cleaning mechanism comprises an activation means for activating the cleaning mechanism.

8. A sensor cleaning device according to claim 7, wherein the activation means comprises a collar located around a main body of the sensor cleaning device.

9. A sensor cleaning device according to any preceding claim, wherein a base cap comprising adhesive pads is attached to the sensor cleaning device to remove contamination from the cleaning pads.

10. A sensor cleaning device according to claim 9, wherein the adhesive pads are provided in a multi-layer arrangement so that the top layer is easily pealed away to reveal the next fresh adhesive leaf which can perform further cleaning operations on the cleaning pads.

11. A sensor cleaning device according to any preceding claim, wherein the cleaning device comprises a top casing, said top casing comprising means to enable a user to view a sensor before and after the cleaning process.

12. A sensor cleaning device according to claim 1 1 , wherein the top casing comprises illumination means.

13. A sensor cleaning device according to any preceding claim, wherein the at least one cleaning pad comprises an elastomeric material suitable for cleaning a surface of a sensor.

14. A method for cleaning a sensor, said method comprising: providing a cleaning mechanism comprising at least one cleaning pad; providing deployment means to position the at least one cleaning pad in a first configuration wherein the at least one cleaning pad is in a stored position and a second configuration wherein the at least one cleaning pad is capable of engaging with a surface of a sensor to be cleaned.

15. Use of a sensor cleaning device according to any of claims 1 to 13 for removing contamination from a sensor including a Charged Couple Device (CCD) sensor in a Digital Single Lens Reflex (DSLR) camera.