Patent Application
20070291329
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:
a is a drawing illustrating a side view of an optical system of an image scanner and transparent media adapter according to an alternative embodiment of the present invention;
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Refer to
In the embodiment shown in
In other embodiments alternatives to the image side optic 140 are used to shift the focus location of intermediate image 142. In
In this way, the transparent media adapter of the present invention efficiently creates an intermediate image 142 of the transparent media 175 so that the scanner module 110 can capture a digital image of the media 175.
In some embodiments each prism is basically a coated right angle prism that allows light to enter from below (where the diffuser 170 is located) and allows light to exit into the lens array 150 located on the left. Therefore, the first prism 155 has transparent surfaces on the bottom and left side and the 45 degree surface of the first prism 155 is a mirror that reflects light or an internally reflecting surface with an air gap behind the prism.
The second prism 145 is similar to the first prism 155. It has transparent surfaces on the right face and bottom face and is mirrored on the 45 degree surface.
In an embodiment of the present invention, the media holder 160 comprises a media holder base and diffuser 170 and a media holder cover 165. The media holder cover 165 located above the transparent media 175 is transparent.
In the embodiment illustrated in
In
Refer to
In the embodiment illustrated in
Additionally, magnets 280, 285 that are used to couple the existing scan module and the TMA have been added. This allows the TMA and the underlying scan module to properly align and move in a synchronized manner. The magnets 280, 285 keep the TMA aligned with the scan module as it moves from left to right or from right to left. As a result, multiple slides or negatives can be scanned in a single scanning operation.
Since the magnets 280, 285 magnetically couple with each other, the motor and drive system of the existing scan module effectively moves the lens assembly 200 of the transparent media adapter. Therefore, there is no need for a separate motor or drive system for the TMA. This greatly reduces the cost and complexity of the TMA.
As shown in
In this embodiment, the first prism, the second prism, and the lens array are positioned in a horizontal orientation so the overall height of the TMA is reduced making the TMA more compact.
A TMA magnet 280 or a plurality of TMA magnets are attached to the transparent media adapter 200. A scanner magnet 285 or a plurality of scanner magnets is attached to the scan module 210. The TMA magnet 280 couples with the scanner magnet 285. As the scan module 210 moves across the transparent media 275 the magnetically coupled transparent media adapter 200 moves in a synchronized manner in the same direction and creates an intermediate image of the transparent media 275 using light from the scan module 210. This allows images of larger or multiple transparent media objects to be captured.
A plurality of sliders 295 is positioned on the bottom of the TMA 200 to enhance movement of the TMA 200. These sliders cooperate with the physical properties of the media holder cover 265 to provide a low friction environment in which the TMA moves across the media holder cover 265. In some embodiments multiple sliders are used. In other embodiments a single slider is used. In yet other embodiments, the bottom of the TMA is treated, coated, or fabricated from low-friction material to act as a slide.
In the embodiment illustrated in
In another embodiment of the present invention, the TMA module or scan module use a metal plate instead of a magnet, as long as the magnet on the other module is strong enough to provide sufficient coupling to the metal plate. For example, when using a scan module with a metal plate instead of a magnet installed, positioning a magnet or magnets on the TMA module allows the magnet of the TMA module to couple with the metal plate on the scan module and follow the scan module movement. Alternatively, a metal plate is attached to the TMA. A magnet on the scan module couples to the metal plate and allows the TMA to move with the scan module.
Refer to
In
This view illustrates the direction of light through the TMA. In use, the transparent media 375 is installed in the media holder 370. Once the scan operation begins, light is emitted from the light source 315 of the scan module. This light is diffused by the diffuser and illuminates the transparent media. The light shines onto the third prism 390 and is reflected to the first prism 355. This light is then reflected into the lens array 350 and travels to the second prism 345. The second prism 345 reflects the light onto the third prism 390 that reflects the light to the image side optical component. The image side optical component creates an optical path difference that shifts the focus location of intermediate image between the transparent media adapter and the scanner platen glass. The lens array 320 of the scan module cooperates with the sensor of the scan module to capture an image of the transparent media. As a result, light from a light source of a scan module is used to effectively and efficiently illuminate the transparent media and the optical components in the TMA create an intermediate image that can be captured by lens array 320 of the scan module.
The light rays forming the intermediate image created by the TMA can be captured by the underlying scan module as long as the capture angle of the underlying scanner is larger than the light angels that form the intermediate image. For the 12E lens array, the capture angle is approximately 6 degrees in the y direction and 12 degrees in the x direction (along the scan line). For a TMA using the 12B lens array from Nippon Sheet Glass, the light angles at the intermediate image allow the image to be completely captured provided the 12E and 12B are aligned to +/−0.5 mm. Beyond this range, the percentage of light captured decreases as the misalignment increases. This means it is important to achieve good alignment and good magnetic tracking to capture all the light present in the intermediate image.
In the above embodiments, the TMA comprises two or three prisms; first prism and second prism or first prism, second prism, and third prism. In the embodiment illustrated in
In an embodiment of the present invention, the TMA is manufactured by creating an outer molded assembly and aluminizing the inner surfaces. For example, using the prisms as a mold insert, the housing is molded around the prisms. When the mold insert is removed, all the inner surfaces of the part are aluminized to be reflective. As a result, a mirrored cavity in the shape of the prisms is achieved. Alternatively, the TMA is built with glass or plastic. In other embodiments the prisms are mirrors, mirrored surfaces, or other types of reflective surfaces.
Furthermore, in some embodiments of the present invention, the TMA comprises optical fibers to transfer light from illuminated media to the image side optic module. This allows the passive transparent media adapter to achieve an extremely low profile. For example, a plurality of optical fibers is installed in a housing. Light from the illuminated media travels through the optical fibers and is emitted at the intermediate image focal plane.
As described above, the present invention provides a compact, low cost transparent media adapter that is magnetically coupled to the scan system. This allows the cost of the transport system to be reduced because the need for a motor and drive system are eliminated.
The present invention utilizes light from the system's existing scan module to backlight transparent media and focuses this light to create an intermediate image of the transparent media so it can be imaged by the underlying scanner module. The TMA transfers the media image to the correct focal plane for the underlying scan module. This is particularly important for CIS based scanners because they have very shallow depth of field and cannot scan media that is above the platen glass.
Additionally, the TMA is passive meaning it has no active electronic components. As a result, it is simpler to integrate into existing scan systems because it utilizes the existing illumination and sensor systems and their corresponding control systems. Since the TMA has no active electronics or illumination, it does not require control or power to operate. The magnetic coupling allows the optical components to be optimized to efficiently illuminate and image a narrow section of the media that moves in sync with the scan module. This allows multiple frames of negative and slides to be captured in a minimal amount of time.
The passive transparent media adapter of the present invention solves the problem of how to flatten and scan transparent media for a CIS or reduced optics based scanner. Because it is passive, it reduces the cost and complexity of the TMA solution.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the invention and its equivalent.
