Multiple-resolution scanning device

A multiple-resolution scanning device introduces an image information obtained by scanning a document into a light folding device and the image information is reflected in the light folding device. The image information comes out from the light folding device and received and reflected by a final reflection mirror unit, and passes through a lens unit and then focused on an optical sensor. By adjusting the light folding device or the final reflection mirror unit, or by adjusting the light source and the light folding device to change the position or angle thereof to achieve the purpose of changing the path of light of the image information and obtain the scanned results having different resolutions.

FIELD OF THE INVENTION

The present invention relates to a scanning device with a multiple-resolution feature which is achieved by changing the light path of the information of an object.

BACKGROUND OF THE INVENTION

There are different requirements for scanning documents and films due to the ranges and the requirements of resolutions are different so that specific document scanners and specific film scanners are developed to meet the requirements.

The trend for the modem scanning devices is to include a higher resolution and a lower resolution in one scanning device. This purpose can be reached by using multiple sets of optical sensors and lenses. The purpose may also be reached by using reflection mirrors and lenses to change the paths of the light, and using masks to obstacle the paths of light and to change the paths of the light.

The devices mentioned employ multiple sets of lenses and sensors and which increase manufacturing cost. The resolution is limited by the number of sets of sensors and lenses so that the present scanners cannot meet the requirements of increase of the resolution for the needs of the market. Therefore, the conventional way by installing multiple sets of sensors and lenses in a scanning device to have a dual-resolution feature cannot catch up the requirements of market.

SUMMARY OF THE INVENTION

The present invention is a multiple-resolution scanning device that changes paths of light to have the multiple-resolution.

The scanning device is embodied as a multiple-resolution scanning device which comprises:

at least one light source which is used to illuminate the documents to be scanned to get the images;

a light folding device having a first reflection mirror and a second reflection mirror which faces the first reflection mirror such that the images introduced by the light folding device is reflected between the first reflection mirror and the second reflection mirror;

a final reflection mirror unit comprising at least one reflection mirror which receives the images coming from the light folding device;

a lens located in the path where the images are reflected from the final reflection mirror unit and focusing on the images;

an optical sensor for receiving the focused images from the lens; and

at least one driving device for driving one of the light source, the light folding device, and the final reflection mirror unit so as to change the status of the assembly.

By adjusting the angle or position of the light folding device, or by adjusting the angle or position of the final reflection mirror unit, or by adjusting the positions of the light folding device and the light source simultaneously, the purpose of changing the path of light can be achieved and the scanning device may have a dual-resolution feature.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, the image of the original document1is focused onto an optical sensor2by a lens3. The distance between the document1and the lens3is designated by “p” which means a path of light between the original document1and the lens3. The distance between the images and the lens3is designated by “q” which means a path of light between the sensor2and the lens3. The focus of the lens3is designated by “f”. An equation for obtaining an image is expressed by 1/p+1/q=1/f.

The definition of magnifying rate is M=q/p.

The path of light is designated by T=p+q.

Accordingly, the magnifying rate can be increased by shortening “p” or “T”.

When “p” is shortened, the image of the original document4as shown by dotted lines is focused onto the sensor2by the lens3. The magnifying rate is increased with the shortening of the distance between the original document4and the lens3. In order to meet the equation mentioned above, the distance “q” between the image and the lens3has to be adjusted to be “q′” so as to have a better focused result.

The distance “p” is changed to be “q′”, and “p′” is less than “p”. The distance “q” between the image and the lens3is changed to be “q′” (the change between the q and q′ is obtained by changing the distance between the lens and the position of the final image, and q′ is close to q). The final M′ (=q′/p′) is larger than the original M (=q/p).

For example, if the original document1has an 8-inch width and the sensor2has 9600 sensing units, the image information of the 8-inch is recorded into the 9600 sensing units and has a resolution of 1200 dpi. If the original document4has a 4-inch width, the image information of the 4-inch width is recorded into the 9600 sensing units to have a resolution of 2400 dpi.

The principle of the present invention is to adjust the light path to increase the magnifying rate M and the resolution, and will be described hereinafter.

Assembly of the First Type

Referring toFIG. 2, a light folding device12and a final reflection mirror unit13are connected to a base11. A lens module14and a sensor15are located in the light path of the final reflection mirror unit13. The final reflection mirror unit13includes a first reflection mirror25which is located beside the light folding device12.

The lens module14is driven by a driving device16(which can be a motor or solenoid valve) to move along the path indicated by the arrows.

The light folding device12includes a first reflection mirror21and a second reflection mirror22which is located in opposite to the first reflection mirror21. Each of the first reflection mirror21and the second reflection mirror22is composed of a single reflection mirror.

Referring toFIGS. 3 and 4, at the second end24of the light folding device12is provided an angle driving device31which is composed of a power supply member32(such as a servo or step motor) for driving a worm rod33and a worm wheel34. The worm wheel34is fixed on the second end24of the light folding device12, and the second end24is pivotally connected to the base11. When the worm rod33is driven by the power supply member32, the worm wheel34and the light folding device12are rotated.

It is to be noted that the angle driving device31as shown inFIG. 3for driving the light folding device12can also be replaced with a simple solenoid valve (not shown). The angle driving device31may also be connected to the first end23of the light folding device12.

Referring toFIG. 5, the lens module14and the sensor15are connected to the base11by pair. The lens module14is fixed and the sensor15is connected to a slide frame35with which the sensor15is moved.

The slide frame35is driven by a displacement driving device36which includes a power supply member (such as a servo or step motor), a threaded rod38and a nut39which is fixed on the slide frame35. The threaded rod38extends through the nut39and is driven by the displacement driving device36. When the threaded rod38is rotated by the power supply member37, the slide frame35slides and the sensor17can approach to or move away from the lens module14so as to change the distance between the sensor15and the lens module14.

The lens module14can be movable and is driven by the displacement driving device36, and the sensor15can be fixed. By this arrangement, the purpose of changing the distance between the sensor15and the lens module14can also be reached.

The First Embodiment of the First Type

FIG. 6shows the path of light and the structure of the first type of the present invention. The light source10lights on document44and the optical image obtained by the scanning on the document is defined to be the image information41which is introduced into the light folding device12and reflected between the first reflection mirror21and the second reflection mirror22of the light folding device12.

After the image information41passed through the light folding device12, it is received by the first refection mirror25of the final reflection mirror unit13and then reflected out. The image information41reflected out passes through the lens module14and is received by the sensor15.

The summation of the path of the image information41in the light folding device12and the path that the image information41is reflected from the final reflection mirror13to the lens module14is defined as “p”. The distance between the lens module14and the sensor15is defined as “q”. The focus distance of the lens module14is “f”.

When the image is clear in the sensor15, the relationship between the p, q, and f has to meet the limitation of the principle of forming an image. The total path of light T=p+q. The rate of magnifying M=q/p. In this embodiment, the image information41is reflected 6 times in the light folding device12.

FIG. 7shows the path of light when the light folding device12is adjusted. This is achieved by driving the first reflection mirror21and the first reflection mirror22of the light folding device12by the angle driving device (not shown) respectively.

The image information41is received and reflected by the light folding device12and the final reflection mirror unit13. When the sensor15gets the clear image, the total path of light T′=p′+q′, the rate of magnifying M′=q′/p′. The image information41is reflected 4 times in the light folding device12.

In order to let the image information41be precisely focused on the sensor15, the position of the lens module14or the sensor15has to be adjusted slightly. In practical use, the adjustment of the value of the q is very minor, the q′ after being adjusted is almost the same as the value of the q.

The way of adjusting the value of q is shown inFIGS. 2 and 3. The lens module14is driven and moved along the arrows by the driving device16which can be a solenoid valve, step motor or other linear driving assembly.

Comparing the results of the FIG.6andFIG. 7, the p′ that the image information41is reflected 4 times is less than the p that the image information41is reflected 6 times, and the q′ is close to the q. Therefore, the rate of magnifying M′ is larger than the M, and the resolution is increased.

The Second Embodiment of the First Type

FIG. 8shows the path of light and the structure of the result of rotating the light folding device12and the second reflection mirror22. The second reflection mirror22of the light folding device12is rotated an angle by the angle driving device (not shown).

After the image information41passed through the light folding device12, the path of the reflection of the image information41is changed dramatically when compared with the path inFIG. 6, so that the p is changed. By changing the q or f, we can have the image with different resolutions. The total path of light T″=p″+q″, the rate of magnifying M″=q″/p″. The image information41is reflected 2 times in the light folding device12. The p″ is less than the p′, so that the rate of magnifying from the largest to the smallest is M″, M′ and M.

The Third Embodiment of the First Type

FIG. 9shows the light folding device12is composed of multiple sub-reflection mirrors42,43and the path of light thereof. At least one of the sub-reflection mirrors42, or43can be changed its angle or position by cooperating with the angle driving device (not shown) or position driving device (not shown).

When the image information41enters in light folding device12, the image information41reflects between the sub-reflection mirrors42,43. The value of p is changed by changing the angle or position of at least one of the sub-reflection mirrors42or43, a scanned image with different resolution can be obtained by cooperating with the changes of the value of q or f. It is to be noted that the sub-reflection mirrors42and43do not have be flat. They can be arranged to obtain the path of light as desired.

Assembly of the Second Type

FIG. 10shows the assembly of the second type. The assembly includes a base11which has a light folding device12and a final reflection mirror unit13. A lens module14and a sensor15are connected to the light path of the final reflection mirror unit13. The final reflection mirror unit13includes a first reflection mirror25and a second reflection mirror26. The final reflection mirror unit13is slightly different from that of the assembly of the first type.

FIG. 11shows the path of light and the structure of the assembly of the second type of the present invention. The final reflection mirror unit13includes a first reflection mirror25and a second reflection mirror26. At least one of the first reflection mirror25and the second reflection mirror26is moved or rotated by a driving means (not shown) so as to change the configuration of the assembly. As shown in the drawing, the image information41is reflected 4 times in the light folding device12. After being reflected, the image information is received by the second reflection mirror26of the final reflection mirror unit13and sent to the lens module14.

FIG. 12shows the path of light and the structure when the first reflection mirror25of the final reflection mirror unit13is moved. The first reflection mirror25of the final reflection mirror unit13is moved by the driving device (not shown) into the light folding device12. By this way, the image information41is reflected in the light folding device12, the image information41is received by the first reflection mirror25and passes through the lens module14. The image information41is reflected 2 times in the light folding device12.

Comparing the path of light shown in theFIGS. 11 and 12, the value of p when the image information41is reflected 2 times is less than the value of p when the image information41is reflected 6 times. The value of q after being adjusted is close to the value of the original q. The rate of magnifying increases when the value of p decreases.

The Second Embodiment of the Second Type

FIG. 13shows that one of the sub-reflection mirrors42in the light folding device12is deemed to be a part of the final reflection mirror unit13, and the structure and the path of light are shown in this figure. The first reflection mirror21and the second reflection mirror22of the light folding device12are respectively composed of a plurality of sub-reflection mirrors42,43. One of the sub-reflection mirror42of the first reflection mirror unit21and the second reflection mirror26are cooperated to be the final reflection mirror unit13. When the sub-reflection mirror42is located on a top of the light folding device12as shown in dotted lines, the image information41is reflected 6 times in the light folding device12(not shown).

When the sub-reflection mirror42is driven by the driving device (not shown) to a position in front of the second reflection mirror26, the sub-reflection mirror42is rotated and the image information41is reflected in the light folding device12. The image information41is received in the shifted sub-reflection mirror42and reflected to and passes through the lens unit14and then is received by the sensor15. The image information41is reflected 4 times in the light folding device12. Accordingly, the rate of magnifying can be increased by adjusting the position and the angle of the sub-reflection mirror42.

The Third Embodiment of the Second Type

FIG. 14shows the structure and the path of light after the second reflection mirror26of the final reflection mirror unit13is adjusted. This arrangement is to move the second reflection mirror26away from the light folding device12.

After the image information41is reflected in the light folding device12, the image information41is received by the fixed first reflection mirror25and then reflected to the second reflection mirror26. The image information41then passes through the lens unit14and is received by the sensor15.

Comparing the results inFIGS. 11 and 14, the path of light of the image information41inFIG. 11does not reach to the first reflection mirror25. However, the path of light of the image information41inFIG. 14reaches to the first reflection mirror25and the second reflection mirror26. The image information41then passes through the lens unit14and becomes an image on the sensor15. It is to be noted that the image information41inFIG. 11is different from that in FIG.14.

The image information41is reflected 6 times in the light folding device12before the final reflection mirror unit13is adjusted, and the image information41is reflected 1 time in the light folding device12after the final reflection mirror unit13is adjusted. Therefore, the rate of magnifying can be increased.

FIG. 15shows an equivalent of the embodiment. The first reflection mirror25of the final reflection mirror unit13is fixedly connected to a side of the light folding device12and located adjacent to the second reflection mirror unit22and the second reflection mirror26of the final reflection mirror unit13. The second reflection mirror26of the final reflection mirror unit13is able to be driven by the driving device (not shown) and receives the image information41as shown in dotted lines. In this situation, the image information41does not reach to the first reflection mirror25.

It is advantageous that when designing the device, the first reflection mirror25can be first fixed by referencing the factors and is cooperated with the movable second reflection mirror26. There will be more flexibility while the resolution is adjusted from 1200 dpi to 1800 dpi, 2400 dpi or 3600 dpi.

The Fourth Embodiment of the Second Type

FIG. 16shows the structure and the path of light after the first reflection mirror25of the final reflection mirror unit13is located in the light folding device12. The first reflection mirror25is located in the light folding device12, it is located at an angle that the image information41will not be reflected to the lens unit14. The image information41is reflected 6 times in the light folding device12, and is received and reflected by the second reflection mirror26.

FIG. 17shows the structure and the path of light after the first reflection mirror25is rotated. The image information41is reflected between the first reflection mirror21and the second reflection mirror22of the light folding device12. Due to the first reflection mirror25is rotated an angle, the image information41is reflected in the light folding device12and reaches to the first reflection mirror25but not to the second reflection mirror26. The image information41is only reflected 2 times in the light folding device12.

The value p after the 2-time reflection in the light folding device12is obviously less than that after 6-time reflection. Therefore, under the situation that the value of q is almost not changed, the rate of magnifying with a smaller value of p can be increased.

The Fifth Embodiment of the Second Type

FIG. 18shows the structure and the path of light when the final reflection mirror unit13is a movable second reflection mirror26. The second reflection mirror26can be driven horizontally by a driving device (not shown). After the image information41in the light folding device12is reflected 4 times, the image information41is received by the second reflection mirror26and passes through the lens unit14. The image information41is focused in the lens unit14and passed to the sensor15.

FIG. 19shows the structure and the path of light after the second reflection mirror26is moved toward the lens unit14. The image information41obtained by scanning the document is introduced in the light folding device12. The second reflection mirror26is moved toward the lens unit14by a driving device (not shown). The image information41reflected twice between the first reflection mirror21and the second reflection mirror26of the light folding device12is received by the second reflection mirror26, and the image information41passes the lens unit14and is received by the sensor15.

The value p after the 2-time reflection in the light folding device12is obviously less than that after 4-time reflection. Therefore, under the situation that the value of q is not changed, the rate of magnifying can be increased by moving the second reflection mirror26.

The Sixth Embodiment of the Second Type

FIG. 20shows the structure and the path of light when the final reflection mirror unit13is a rotatable reflection mirror27. The reflection mirror27is driven by an angle driving device (not shown) so as to perform different angular status. The image information41obtained by scanning the document is introduced in the light folding device12. The image information41is reflected 6 times in the light folding device12and is received by the reflection mirror27and passes through the lens unit14and received by the sensor15.

FIG. 21shows the structure and the path of light when the reflection mirror27is rotated an angle such that the path of light of the image information41inFIG. 20does not reach to the lens unit14via the reflection mirror27.

Instead, another path of light of the image information41is reflected in the light folding device12. The path of light is received by the reflection mirror27and passes through the lens unit14and received by the sensor15. The image information41is reflected 2 times in the light folding device12.

Therefore, the value of p when the image information41is reflected 2 times in the light folding device12is less than the value of p when the number of reflection is 6. Under the condition that the value of q is not changed, the rate of magnifying can be increased by rotating the reflection mirror27.

Assembly of the Third Type

FIG. 22shows the structure and the path of light of the third type assembly. The difference between the first type is that the first reflection mirror21of the light folding device12can be moved.

FIG. 24shows the structure and the path of light of the third type. The difference between the first type is that the first reflection mirror21of the light folding device12can be moved.

The First Embodiment of the Third Type Assembly

Referring toFIG. 22, the first reflection mirror21is moved away from the light source10which is not movable (from the position shown in dotted lines to the position shown in solid lines). The image information41is reflected 4 times in the light folding device12, and is finally reflected by the final reflection mirror unit13to the lens unit14and become an image in the sensor15. The final reflection mirror unit13is a single reflection mirror.

FIG. 23shows the structure and the path of light when the first reflection mirror21is moved further away from the light source10. The first reflection mirror21is moved further away from the light source10which is not movable (from the position shown in dotted lines to the position shown in solid lines). The image information41is reflected 2 times in the light folding device12, and is finally reflected by the final reflection mirror unit13to the lens unit14and become an image in the sensor15.

Comparing the results ofFIGS. 22 and 23, the farther the first reflection mirror21is away from the light source10, the number of times of reflection of the image information41between the first reflection mirror21and the second reflection mirror22is less. The value of p due to the reflection of the image information becomes smaller. Under the condition that the value of p is reduced and the value of q is increased, moving the first reflection mirror21away from the light source10causes a larger resolution and rate of magnifying.

Comparing the results ofFIGS. 22 and 23, the image information41in those two situations is different, due to the scattering of the light on the scanned document, when the illumination condition is accepted, different paths of light of the image information41may have clear scanning result.

The Third Embodiment of the Second Type Assembly

Referring toFIG. 24, the light source10and the light folding device12are movable from the position shown in dotted lines to the position shown in solid lines. For example, the first reflection mirror21of the light folding device12can be made to be movable and the light source10is also movable. The first reflection mirror21and the light source10can be fixed on the same base (not shown).

When the first reflection mirror21and the light source10are moved, the first reflection mirror21and the light source10are moved relative to the second reflection mirror22, so that the relative position between the light folding device12and the light source10can be accordingly adjusted. The image information41is reflected 4 times between the first reflection mirror21and the second reflection mirror22of the light folding device12. The image information41is finally received and reflected by the final reflection mirror unit13and becomes an image on the sensor15.

FIG. 25shows the structure and the path of light when the first reflection mirror21and the light source are moved. As shown in the figure, the first reflection mirror21is moved further away from the second reflection mirror21, and the light source10is closer to the second reflection mirror22(from the position shown in dotted lines to the position shown in solid lines). The area of the first reflection mirror21facing the second reflection mirror22becomes smaller so that the image information41is reflected 2 times between the first reflection mirror21and the second reflection mirror22. The image information41is reflected by the final reflection mirror unit13and passes through the lens unit14and becomes an image on the sensor15.

Comparing the results of theFIGS. 24 and 25, the first reflection mirror21and the light source10are simultaneously moved to left, the corresponding area between the first reflection mirror21and the second reflection mirror22becomes smaller. The number of reflection between the first reflection mirror21and the second reflection mirror22becomes less. The image information41is projected on a distal end of the second reflection mirror22and the value p resulted in the reflection of the image information41becomes smaller. Under the condition that the value of p is smaller and the value q changes in a minor way, a larger rate of magnifying and resolution can be obtained by moving the first reflection mirror21away from the second reflection mirror22, and by moving the light source10close to the second reflection mirror22.

The Third Embodiment of the Third Type Assembly

FIG. 26shows the structure and the path of light of the light folding device12wherein the first reflection mirror21is composed of a plurality of sub-reflection mirrors42. At least one of the sub-reflection mirror42of the first reflection mirror21is movable so that any one of the sub-reflection mirror42can be moved away from or close to the light source10. In normal condition, the image information41is reflected 6 times in the light folding device12.

FIG. 27shows the structure and the path of light when the light source10is not movable and the sub-reflection mirror42is moved. When proceeding the adjustment, the light source10is not movable and the sub-reflection mirror42is moved toward the sub-reflection mirror42. The path of the image information changes and is reflected 4 times between the first reflection mirror21and the second reflection mirror22.

FIG. 28shows the structure and the path of light when the light source10is not movable and the sub-reflection mirrors42at the right and middle of the first reflection mirror21are moved to the left toward the sub-reflection mirror42. As shown in the figure, the sub-reflection mirrors42are moved away from the light source10so as to avoid the original image information41. The other image information41is reflected 2 times between the sub-reflection mirror42of the first reflection mirror21and the second reflection mirror22after it is entered in the light folding device12. The image information41is received and reflected by the final reflection mirror13and passes through the lens unit14and becomes an image on the sensor15.

Comparing the results of theFIGS. 27 and 28, it is noticed that when adjusting any of the sub-reflection mirror42of the first reflection mirror21reduces the number of reflection of the image information41between the first reflection mirror21and the second reflection mirror22. The value of p formed by the reflection of the image information becomes smaller under the condition that the value of p is obviously reduces and q is not changed too much, a larger rate of magnifying and resolution can be obtained by adjusting the relative position between any one of the sub-reflection mirrors42of the first reflection mirror21and the light source10.

The Fourth Embodiment of the Third Type Assembly

FIG. 29shows the structure and the path of light when the sub-reflection mirror42and the light source10are moved. The first reflection mirror21of the light folding device12is composed of a plurality of sub-reflection mirrors42. At least one of the sub-reflection mirrors42of the first reflection mirror21and the light source are moved by a driving device (not shown).

When moving one of the sub-reflection mirrors42at the right of the first reflection mirror21toward the sub-reflection mirror42at the left and moving the light source10toward the second reflection mirror22. The image information41is reflected 4 times between the first reflection mirror21and the second reflection mirror22.

Comparing the results of theFIGS. 26 and 29, it is noticed that when the light source is moved close to the second reflection mirror22, and the sub-reflection mirrors42of the first reflection mirror21are moved toward with each other, the number of times of reflection between the first reflection mirror21and the second reflection mirror22is reduced. The value of p formed by the reflection of the image information becomes smaller under the condition that the value of p is obviously reduces and q is not changed too much, a larger rate of magnifying and resolution can be obtained by adjusting the sub-reflection mirror42of the first reflection mirror21and the light source10.

CONCLUSION

In the types of assembly mentioned above, the angle driving device31for driving the light folding device12, the driving device for driving the final reflection unit13, and the driving device for simultaneously driving the light source10and the light folding device12are not necessarily existed simultaneously. In other words, at least one of the driving devices to drive its corresponding item can achieve the purpose of changing the path of light of the image information.

The adjustment can be automatically completed when the users sets the resolution and the types of the document to be scanned. The lens unit14and the sensor15automatically adjust the focus distance and the image distance needed, and this is easily to be operated.