WO2010002840A2

WO2010002840A2 - Two dimensional flatbed scanner with no moving parts

Info

Publication number: WO2010002840A2
Application number: PCT/US2009/049175
Authority: WO
Inventors: Min-Hao "Michael" Lu
Original assignee: Lu Min-Hao Michael
Priority date: 2008-06-30
Filing date: 2009-06-30
Publication date: 2010-01-07
Also published as: WO2010002840A3

Abstract

Provided is a flatbed scanner having a two-dimensional image sensor. The flatbed scanner includes a flatbed scanner housing for housing a plurality of flatbed scanner components including a two-dimensional image sensor. The two-dimensional image sensor includes a two-dimensional non-pixelated light source, a first substrate disposed over the two-dimensional non-pixelated light source, and a two-dimensional array of photodetectors disposed over the first substrate where each photodetector effectively surrounds a transparent, non-active region.

Description

TWO DIMENSIONAL FLATBED SCANNER WITH NO MOVING PARTS

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is related to, and claims priority from, US provisional application 61/076,714 filed on June 30, 2008 by Min-Hao Michael Lu entitled "TWO DIMENSIONAL CONTACT IMAGE SENSOR WITH INTEGRATED NON-PIXELATED LIGHT SOURCE", the contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] This invention generally relates to a two- dimensional contact image sensor with an integrated non- pixelated light source, and more particularly, to their use in a two-dimensional flatbed scanner with no moving parts.

BACKGROUND OF THE INVENTION

[0003] A scanner is a piece of widely used office equipment. It converts a document or image (hereinafter, "the image object") into digital information that can be stored, retrieved and shared electronically. Conventional flatbed scanners operate in a "linear scan and scroll" mode where a scanner head scans one line at a time and is scrolled transversely to scan the entire image (Figure 1). Alternatively, the scanner head is kept stationary and the image object is scrolled. In either implementation, the need for moving parts imposes size limitations, making the conventional scanner unsuitable for integration into mobile devices . It is therefore desirable to have a two dimensional scanner that does not contain any moving parts. Broadly speaking, a scanner is a type of contact image sensor. The present invention relates to a contact image sensor that is composed of a two-dimensional light source and a two- dimensional array of photodetectors .

[0004] U.S. Patent Nos . 5239189, 5313055, 5319182, 6480305, 6717560 and 7046282 disclose various two-dimensional imaging devices that comprise a plurality of light emitting elements interspersed among a plurality of light sensing elements, arranged in two dimensions. However, it may be cost- prohibitive to pattern an array of light-emitting elements to the resolution required by a scanner which is normally in the range of hundreds of dots per inch (dpi) and above. For example, one candidate technology for the light emitting element is inorganic light emitting diodes (LEDs) . Inorganic LEDs are generally made from crystalline semiconductors such as GaAs, AIGaAs or InGaN, and can be patterned using conventional photolithographic techniques. However, the contact image sensor must be of comparable size to the image object which entails using an expensive, large semiconductor wafer as the substrate.

[0005] Another candidate for the light emitting element is organic light emitting devices (OLEDs) . OLEDs can be fabricated on amorphous substrates such as glass which are cheaper than compound semiconductor wafers. On the other hand, the organic material and reactive cathode in the OLED are easily degraded in the conventional photolithographic process. Currently, OLEDs are patterned by evaporation through a shifting fine shadow mask or by inkjet deposition in solution-processed OLEDs. The material utilization rate in VTE (vacuum thermal evaporation) is low. Solution-processed OLEDs are less mature than their evaporated counterparts. InkJet deposition may be more time consuming and have different dynamics from spin-casting, the standard process for depositing solution-processed OLEDs. Accordingly, the present invention utilizes a large area, non-pixelated light source that circumvents the need for patterning the light emitting elements .

[0006] Therefore, there is a need for a two-dimensional flatbed scanner that does not require moving parts, yet does not involve expensive pixelated light emitting elements .

INDUSTRIAL APPLICABILITY

[0032] The present invention has significant industrial application in the field of flatbed scanners and image sensor technology.

SUMMARY OF THE INVENTION

[0008] In an aspect of the invention, A two-dimensional contact sensor that is composed of a two-dimensional array of photodetectors and a non-pixelated two-dimensional light source is provided. An optional array of color filters may be placed above the photodetectors to enable full-color imaging. There are two alternative structures in implementing the present invention. In one alternative, the light source is above the photodetectors. In the other alternative, the light source is below the photodetectors. As used herein, "above" is intended to mean that the component is closer to the image object, whereas "below" is intended to mean that the component is further away from the image object.

[0009] In another aspect of the invention, the flatbed scanner as described here may use any of an assortment of photodetectors, including amorphous silicon (a-Si) p-i-n or n- i-p photodetectors, charge-coupled detectors (CCDs), organic photodetectors, or any other device that converts photons into electric signals, without limitation.

[00010] Another aspect of the invention provides that the light source may be a substrate with an edge-coupled fluorescent light, or a substrate with edge-coupled LEDs. Light from the edge may be waveguided in the substrate and emitted in a direction substantially normal to the substrate. The substrate may be treated to enhance emission from one side or to enhance uniformity of the emission. Such treatment may include texturing one surface of the substrate or laminating a film onto one surface of the substrate. The light source may also be an organic light emitting device (OLED), which may be fabricated on top of the photodetectors or may be fabricated on a separate substrate. For monochromatic (e.g., black/white or grey scale) imaging, the light source may be monochromatic. A monochromatic light source is defined herein as one where light is emitted from a single molecular species. For full- color imaging, a light source with a broad spectrum, including components in the red, green and blue regions of the visible spectrum may be used in conjunction with RGB color filters deposited on the photodetectors. The light source is non- pixelated in that its emission is substantially contiguous and uniform over an area much larger than that of a single pixel. More preferably, the light source and the image sensor are substantially equal in area.

[0011] Another aspect of the invention provides a substantially transparent light source in embodiments where the light source is above the photodetectors. Therein, the light reflected by the image object is transmitted through the light source before reaching the photodetectors. In embodiments where the light source is below the photodetectors, there may be structures that reduce light entering the photodetectors directly without being reflected off the image object.

[0012] In various aspects of the invention where the light source is below the photodetectors, each photodetector may effectively surround a transparent, non-active region. During device operation, the light emitted by the light source passes through said transparent, non-active region, reflects off the image target, and is detected by the photodetectors . Having the photodetector effectively surrounding the transparent, non-active region ensures that the reflected light is detected by the proper pixel rather than being waveguided into adjacent pixels which contributes to the noise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram illustrating the linear scroll and scan mode of operation employed in prior art conventional scanners;

[0014] Figure 2 is a cross-sectional schematic diagram illustrating a typical prior art a-Si p-i-n or n-i-p photodetector ;

[0015] Figure 3 is a cross-sectional schematic diagram illustrating a typical prior art OLED;

[0016] Figure 4 is a circuit diagram illustrating a pixel or subpixel in an active-matrix array of photodetectors, in accordance with an embodiment of the present invention; [0017] Figure 5 is a cross-sectional view of an exemplary two-dimensional image contact sensor with integrated non- pixelated light source, in accordance with an embodiment of the present invention;

[0018] Figure 6 is a cross-sectional view of another exemplary two-dimensional image contact sensor with integrated non-pixelated light source, in accordance with an embodiment of the present invention;

[0019] Figure 7 is a cross-sectional view of another exemplary two-dimensional image contact sensor with integrated non-pixelated light source, in accordance with an embodiment of the present invention; [0020] Figures 8A and 8B depict a single photodetector for an exemplary embodiment of the present invention wherein the light source is placed below the photodetectors;

[0021] Figure 9 depicts a schematic cross-sectional view of an embodiment of the present invention in which the light source lies further away from the image object than the array of photodetectors;

[0022] Figure 10 depicts a schematic cross-sectional view of an embodiment of the present invention in which the light source lies further away from the image object than the array of photodetectors;

[0023] Figure 11 depicts a schematic cross-sectional view of an embodiment of the present invention in which the light source lies further away from the image object than the array of photodetectors; and

[0024] Figure 12 depicts a schematic cross-sectional view of an embodiment of the present invention in which the light source lies further away from the image object than the array of photodetectors.

DETAILED DESCRIPTION

[0025] In the following description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one having ordinary skill in the art, that the invention may be practiced without these specific details. In some instances, well-known features may be omitted or simplified so as not to obscure the present invention. Furthermore, reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment .

[0026] The present invention advantageously provides for a two-dimensional flatbed scanner that does not require moving parts, yet does not involve expensive pixelated light emitting elements or a large semiconductor wafer as the substrate.

[0027] The invention as described herein with reference to particular exemplary embodiments may also be embodied in different forms and should not be construed as limited the embodiments as set forth herein. For example, although the embodiments below are substantially directed to a-Si photodetectors, the configurations and structures of the present invention are applicable to other photodetectors, such as organic photodetectors.

[0028] Throughout this application the terms "effectively surrounds" and "effectively surrounding" are used with respect to embodiments of the present invention wherein each photodetector surrounds a transparent, non-active region. This term and its variants is used to indicate that the photodetector may completely surround the non-active region, or, in the alternative, the photodetector may surround the the non-active region on three sides, leaving a gap where the fourth side would be, without limitation.

[0029] Conventional scanners generally employ a linear scroll and scan mode of operation, such as represented in

Figure 1. Typically, a scanner head 100 is composed of a linear array of photodetectors 101 and a linear light source

102. The scanner head scrolls transversely to complete a scan .

[0030] Figure 2 depicts a cross-sectional schematic diagram of a typical a-Si p-i-n or n-i-p photodetector, showing a substrate 200, a first electrode 202, a first doped layer 204, an intrinsic layer 206, a second doped layer 208 and a second electrode 210.

[0031] Figure 3 depicts a cross-sectional schematic diagram of a typical prior art OLED. This depiction includes a substrate 300, a first electrode 302 that may also include a first charge injection layer at the interface between the first electrode 302 and a group of organic layers 304 that may include one or several of the following: a first charge transport layer, an emitting layer, a charge blocking layer, and a second charge transport layer. Also depicted is a second electrode 306 that may also include a second charge injection layer at the interface between the organic layers 304 and the second electrode 306.

[0032] Figure 4 is a circuit diagram of an exemplary pixel or subpixel in an active-matrix array of photodetectors, which includes a gate line 400, a data line 402, a bias line 404, a transistor 406, and a photodetector 408.

[0033] A contact image sensor requires, broadly speaking, two components: a light source and a means to detect the light reflected by the image object. The present invention includes a contact image sensor composed of a non-pixelated light source and a two-dimensional array of photodetectors. Prior devices proposed in U.S. Patent Nos . 5239189, 5313055, 5319182, 6480305, 6717560 and 7046282 all feature pixilated light emitting elements. For the light source there are two main candidate solid-state lighting technologies: LED and OLED. Both involve certain challenges which must be overcome if they are to be used in an array of pixilated light emitting elements. LEDs are commonly made with crystalline compound semiconductors that can be patterned with standard photolithographic techniques. However, if pixilated LEDs were to be used as the light source, a large semiconductor wafer would be required as the substrate, which is presently cost prohibitive. OLEDs can be deposited on amorphous substrates; however, they are prone to chemical degradation and cannot be processed using standard photolithographic techniques. Vacuum thermal deposition with shifting shadow masks is the standard patterning method used in manufacturing OLED displays. However, this method has a low material utilization rate, a low process throughput, and requires high precision shadow masks. Therefore, the non-pixelated light source used in the present invention simplifies the manufacturing process and reduces the cost of the end product.

[0034] OLEDs may be produced by well-known conventional means, such as forming electrodes by sputtering or vacuum thermal evaporation, organic layers by vacuum thermal evaporation, spin-coating or inkjet printing, and other techniques, without limitation. Similarly, LEDs may also be formed using known conventional technology, such as forming electrodes by sputtering or vacuum thermal evaporation, and semiconductor layers by chemical vapor deposition or molecular beam epitaxy. Also, a-Si photodetectors may be formed using known methods, such as forming electrodes by sputtering or vacuum thermal evaporation, and a-Si layers by plasma enhanced chemical vapor deposition. Organic photodetectors may also be formed using well-known methods, such as forming electrodes by sputtering or vacuum thermal evaporation, and forming organic layers by vacuum thermal evaporation, spin-coating or inkjet printing.

[0035] To achieve full-color imaging, prior art, such as U.S. Patent No. 6,717,560, proposes detecting reflected light originated from RGB light emitting elements. In contrast, embodiments of the present invention employ RGB color filters on photodetectors in conjunction with a broad-spectrum, non- pixelated light source to generate RGB signals at the pixel level. Pattern deposition of RGB color filters is a mature process that is routinely used in color LCD manufacturing. Thus, devices deploying the present invention are easier to manufacture than are those proposed by the prior art. [0036] There are two structural alternatives in realizing the current invention depending on the relative positioning of the light source and the array of photodetectors . In the first alternative, the light source is above, i.e., closer to the image object than, the array of photodetectors. In this configuration, light is emitted in both the up and down directions. The downward traveling light enters the photodetectors as noise. The upward traveling light is reflected off the image object, travels through the light source and enters the photodetectors as the signal. It is important that the light source is at least partially transparent to its own emission. Throughout this application, the term "partially transparent" is used to denote a transparency of 25% or greater. The light source is to be designed to maximize the signal-to-noise ratio (SNR) by enhancing the upward traveling light relative to the downward traveling light. This may be achieved by any of several methods, such as microcavity effects in an OLED through selecting appropriate thicknesses and indices of refraction of OLED layers, without limitation.

[0037] An embodiment of the invention provides a flatbed scanner having a two-dimensional image sensor. The flatbed scanner includes a flatbed scanner housing for housing the flatbed scanner components. Also included is a two- dimensional image sensor. The flatbed scanner components include a power connector/power supply for powering the electrical components, a control interface for user control of scanner operation, a processor and associated memory, both configured to operate the various electrical components, as well as all required circuitry for interconnection of the components, processor, memory control and power connector/supply. These components are generally well understood in the scanner industry and are provided as required for operation of the flatbed scanner.

[0038] An exemplary two-dimensional image sensor in accordance with an embodiment of the invention includes a two- dimensional non-pixelated light source, a first substrate disposed over the two-dimensional non-pixelated light source, and a two-dimensional array of photodetectors disposed over the first substrate, where each photodetector effectively surrounds a transparent, non-active region.

[0039] Various embodiments of the invention will now be described in the following Examples.

[0040] Example 1: Figure 5 shows a cross-sectional schematic diagram of an embodiment of the present invention in which the two-dimensional light source 508 is above the array of photodetectors 502. The two-dimensional light source 508 consists of a substrate and an LED 510 side-coupled to it. The substrate can be a plain glass substrate or a light diffuser with enhanced light scattering capabilities. Multiple side-coupled LEDs may be employed to enhance the uniformity of the light source. Further, a thin fluorescent light tube may be used in place of the LED. An array of photodetectors 502 are provided. The photodetectors 502 may be a-Si p-i-n or n-i-p photodetectors, a typical cross-section of which can be found in Figure 2. The photodetectors 502 are fabricated on the side of the substrate that is nearest to the light source 508. The array of photodetectors 502 is preferably an active-matrix array where the circuit diagram for each pixel or sub-pixel is illustrated in Figure 4. For monochrome (black/white or grey scale) imaging, color filters are not necessary. For full-color imaging, RGB color filters 504 are deposited over RGB sub-pixels in the array of photodetectors 502. For full-color imaging, the spectrum of the light source needs to be sufficiently broad as to have significant components in the RGB regions of the spectrum. To minimize optical losses, an index-matching gel or adhesive 506 is deployed between the light source 508 and the array of photodetectors 502.

[0041] Example 2: Figure 6 is a schematic drawing of the cross-sectional view of another embodiment of the first alternative implementation of the present invention. It is similar to the previous Figure 5, except an OLED 608 is used as the two-dimensional light source. A representative cross- section of an OLED is shown in FIG. 3. The OLED is deposited on the side of the substrate closest to the photodetectors. The OLED microcavity should be engineered, i.e., the materials with the proper indices of refraction selected and layer thicknesses controlled, to make the majority of the emission towards the image object so that the SNR is enhanced. The OLED may alternatively be deposited on the side of the substrate furthest from the photodetectors, in which case the OLED needs to be encapsulated either with a cover glass or with one or more monolithically deposited thin films. An array of photodetectors 602 is provided. The photodetectors 602 may be a-Si p-i-n or n-i-p photodetectors, a typical cross-section of which can be found in Figure 2. The photodetectors 602 are fabricated on the side of substrate that is closest to the light source. The array of photodetectors 602 is preferably an active-matrix array, where an exemplary circuit diagram for each pixel or subpixel is illustrated in Figure 4. For monochrome (black/white or grey scale) imaging, color filters are not necessary. For full- color imaging, RGB color filters 604 are deposited over RGB subpixels in the array of photodetectors 602. For full-color imaging, the spectrum of the light source needs to be sufficiently broad as to have significant components in the RGB regions of the spectrum. To minimize optical losses, an index-matching gel or adhesive 606 is deployed between the light source and array of photodetectors.

[0042] Example 3: Figure 7 is a schematic drawing of the cross-sectional view of another embodiment of the first alternative. Unlike in Figure 6, here the OLED is deposited directly over the color filter, which lies above the array of photodetectors 702. The active layers of the OLED are depicted in FIG. 3 as layers 302, 304 and 306. It is understood that for monochrome imaging, color filters are not needed. The OLED may be encapsulated from the above with a cover glass 710 and gel or adhesive 708. The OLED may alternatively be encapsulated with monolithically integrated thin films .

[0043] In the second alternative implementation of the present invention, the light source lies below, i.e. further away from the image object, than the array of photodetectors. The present invention discloses devices where the light source is non-pixilated and where each photodetector contains a transparent, non-active region. Figures 8a and 8b show the top and cross-sectional views of a pixel or subpixel in the two-dimensional array. Figure 8a is the top view where the photodetector region 802 and TFT region 818 in each pixel or subpixel are outlined. The photodetector may be in a-Si p-i-n or n-i-p photodetector. The transparent, non-active region is represented by the opening 804. FIG. 8b shows the cross- sectional view along the dash-dot line in FIG. 8a. 806 is a substrate. 808 is the first electrode layer that is opaque. 810 is the first doped a-Si layer. 812 is the intrinsic a-Si layer. 814 is the second doped a-Si layer. 816 is the second electrode layer. A light source is placed below substrate 806. Since the first electrode 810 is opaque, light is prevented from entering the photodetector directly, which would contribute to noise. Instead, light is emitted forward through the opening 804 where it reflects off the image object and enters the photodetector from above. The downward traveling light from the light source is either absorbed or redirected upwards. In an alternative embodiment, the first electrode is transparent, but the same function is accomplished with an opaque interface layer between the first electrode and the substrate.

[0044] Example 4: Figure 9 is a schematic drawing of the cross-sectional view of an embodiment of the second alternative to implement the present invention. Substrate 902 and side-coupled LED 904 are arranged such that the substrate 902 is simultaneously a substrate to the array of photodetectors and a two dimensional light source due to the wave-guided light from the LED 904. The backside of substrate 902 may be treated to enhance the amount or uniformity of light emission. A first electrode layer 906 is opaque. Alternatively, the same function can be served by a transparent first electrode and an opaque interface layer between the substrate and the first electrode layer. A first doped a-Si layer 908 is also provided, as are the intrinsic a- Si layer 910, the second doped a-Si layer 912, and the second electrode layer 914. For monochrome (black/white or grey scale) imaging, color filters are not necessary. In order to achieve full-color imaging, a color filter 916 is deposited over the second electrode 914. The color filter 916 is patterned to match the shape of the photodetector below. For full-color imaging, the spectrum of the light source needs to be sufficiently broad as to have significant components in the RGB regions of the spectrum. The forward emitted light is reflected by the image object 900 which in most instances is not perfectly planar. The reflected light enters the photodetector through the color filter 916, thus the localized RGB information of the image object may be recorded. The device may be sealed from the top with a cover glass and an adhesive or monolithically with one or more thin films. [0045] Example 5: Figure 10 is another schematic drawing of the cross-sectional view of an embodiment of the second alternative to implement the present invention. Examples 4 and 5 are similar except for the insulating layer 1018 surrounding the edge of the first electrode 1008. This insulating layer prevents the photodetectors from shorting. [0046] Example 6: Figure 11 is a schematic drawing of the cross-sectional view of another embodiment of the second alternative to implement the present invention. The two- dimensional-light source 1102 consists of a substrate and an LED 1104 side-coupled to it. The substrate can be a plain glass substrate or a light diffuser with enhanced light scattering capabilities . Multiple side-coupled LEDs may be employed to enhance the uniformity of the light source. Further, a thin fluorescent light tube may be used in place of the LED. 1108 is an array of photodetectors, each containing a transparent, non-active region. The photodetectors may be a-SI p-i-n or n-i-; photodetectors, a typical cross section of which can be found in Figure 8b. The photodetectors are fabricated on the side of substrate that is furthest from the light source. The array of photodetectors is preferably an active-matrix array where the circuit diagram for each pixel or subpixel is illustrated in Figure 4. In order to achieve full-color imaging, a color filter 1110 is deposited over the array of photodetectors. Each color filter 1110 is patterned to match the shape of the photodetector below. For full-color imaging, the spectrum of the light source needs to be sufficiently broad as to have significant components in the RGB regions of the spectrum. To minimize optical losses, an index-matching gel or adhesive 1106 is deployed between the light source and array of photodetectors .

[0047] Example 7: Figure 12 is a schematic drawing of the cross-sectional view of another embodiment of the second alternative to implement the present invention. It is similar to Figure 11, except an OLED 1202 is used as the two- dimensional light source. A representative cross-section of the OLED is shown in Figure 3. The OLED 1202 is deposited on a side of its substrate that is closest to the photodetectors. An array of photodetectors 1206, each containing a transparent, non-active region is also provided. The photodetectors may be a-Si p-i-n or n-i-p photodetectors, a typical cross-section of which can be found in Figure 8b. The photodetectors are fabricated on the side of substrate that is furthest from the light source. The array of photodetectors is preferably an active-matrix array where the circuit diagram for each pixel or subpixel is illustrated in Figure 4. In order to achieve full-color imaging, color filter 1208 is deposited over the array of photodetectors. Each color filter is patterned to match the shape of the photodetector below. For full-color imaging, the spectrum of the light source needs to be sufficiently broad as to have significant components in the RGB regions of the spectrum. To minimize optical losses, an index-matching gel or adhesive 1204 is deployed between the light source and array of photodetectors.

[0048] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims .

Claims

CLAIMS :

1. A flatbed scanner having a two-dimensional image sensor, the flatbed scanner comprising: a flatbed scanner housing for housing a plurality of flatbed scanner components including a two-dimensional image sensor; the two-dimensional image sensor comprising: a two-dimensional non-pixelated light source (1202); a first substrate disposed over the two-dimensional non- pixelated light source; and a two-dimensional array of photodetectors (1206) disposed over the first substrate where each photodetector effectively surrounds a transparent, non-active region.

2. The flatbed scanner according to claim 1, wherein the two-dimensional array of photodetectors (1206) is an active matrix array.

3. The flatbed scanner according to claim 1, wherein the photodetectors (1206) are amorphous Si p-i-n or n-i-p photodiodes .

4. The flatbed scanner according to claim 1, wherein the photodetectors (1206) are organic photodetectors.

5. The flatbed scanner according to claim 1, wherein the two-dimensional non-pixelated light source (1102) is composed of a second substrate and a light source edge-coupled to the second substrate.

6. The flatbed scanner according to claim 5, wherein an inorganic light emitting diode (LED) (1104) is edge-coupled into the second substrate.

7. The flatbed scanner according to claim 5, wherein a cold cathode fluorescent lamp is edge-coupled into the second substrate .

8. The flatbed scanner according to claim 5, wherein one side of the second substrate is non-planar.

9. The flatbed scanner according to claim 5, wherein a thin film is laminated onto one side of the second substrate.

10. The flatbed scanner according to claim 1, wherein the two-dimensional non-pixelated light source (1202) is an organic light emitting diode (OLED) comprising: a second substrate (300); a first electrode (302) disposed over the second substrate; one or more organic layer (s) (304) disposed over the first electrode; and a second electrode (306) disposed over the organic layer .

11. The flatbed scanner according to claim 10, wherein the OLED is disposed over a surface of the second substrate closer to the first substrate and the first and second substrates are glued together with an adhesive or gel (1204) .

12. The flatbed scanner according to claim 1, wherein pixilated color filters are disposed over the array of photodetectors (1208) .

13. The flatbed scanner according to claim 1, wherein an opaque layer blocks emission from the light source in the direction of the photodetectors (1206) except in the transparent, non-active region.

14. A flatbed scanner having a two-dimensional image sensor, the flatbed scanner comprising: a flatbed scanner housing for housing a plurality of flatbed scanner components including a two-dimensional image sensor; the two-dimensional image sensor comprising: a substrate (902) ; a two-dimensional array of photodetectors (908-914) disposed over a first surface of the substrate, and a light source (904) edge coupled into the substrate.

15. The flatbed scanner according to claim 14, wherein each photodetector (908-914) effectively surrounds a transparent, non-active region.

16. The flatbed scanner according to claim 15, wherein the two-dimensional array of photodetectors (908-914) is an active matrix array.

17. The flatbed scanner according to claim 15, wherein the photodetectors (908-914) are amorphous Si p-i-n or n-i-p photodiodes .

18. The flatbed scanner according to claim 15, wherein the photodetectors are organic photodetectors.

19. The flatbed scanner according to claim 15, wherein an inorganic light emitting diode (LED) (904) is edge-coupled into the substrate.

20. The flatbed scanner according to claim 15, wherein a cold cathode fluorescent lamp is edge-coupled into the substrate .

21. The flatbed scanner according to claim 15, wherein the second surface of the substrate is non-planar.

22. The flatbed scanner according to claim 15, wherein a thin film is laminated on the second surface of the substrate.

23. The flatbed scanner according to claim 15, wherein pixilated color filters (916) are disposed over the array of photodetectors (908-914).

24. The flatbed scanner according to claim 15, wherein an opaque layer blocks the waveguide emission from the edge coupled light source in the direction of the photodetectors (908-914) except in the transparent, non-active region.

25. A two-dimensional image sensor comprising: a first substrate (602); a two-dimensional array of photodetectors (604) disposed over said first substrate; and a two-dimensional non-pixelated light source (608) disposed over said array of photodetectors;

where the two-dimensional non-pixelated light source is at least partially transparent to its own emission.

26. The two-dimensional image sensor according to claim 25, wherein the two-dimensional array of photodetectors (602) is an active matrix array.

27. The two-dimensional image sensor according to claim 25, wherein the photodetectors (602) are amorphous Si p-i-n or n- i-p photodiodes .

28. The two-dimensional image sensor according to claim 25, wherein the photodetectors (602) are organic photodetectors.

29. The two-dimensional image sensor according to claim 25, wherein pixilated color filters (604) are disposed over the array of photodetectors .

30. The two-dimensional image sensor according to claim 25, wherein the two-dimensional non-pixelated light source (508) is composed of a second substrate and a light source (510) edge-coupled to the second substrate.

31. The two-dimensional image sensor according to claim 25, wherein the two-dimensional non-pixelated light source (608) is an organic light emitting diode (OLED) comprising: a second substrate (300); a first electrode (302) disposed over the second substrate; one or more organic layer (s) (304) disposed over the first electrode; and a second electrode (306) disposed over the organic layer .

32. The two-dimensional image sensor according to claim 31, wherein the OLED (608) is disposed over a surface of the second substrate closer to the first substrate and the first and second substrates are glued together with an adhesive or gel (606) .

33. A flatbed scanner having a two-dimensional image sensor, the flatbed scanner comprising: a flatbed scanner housing for housing a plurality of flatbed scanner components including a two-dimensional image sensor; the two-dimensional image sensor comprising: a first substrate; a two-dimensional array of photodetectors (602) disposed over said first substrate; and a two-dimensional non-pixelated light source (608) disposed over said array of photodetectors;

where the two-dimensional non-pixelated light source (608) is at least partially transparent to its own emission.

34. The flatbed scanner according to claim 33, wherein the two-dimensional array of photodetectors (602) is an active matrix array.

35. The flatbed scanner according to claim 33, wherein the photodetectors (602) are amorphous Si p-i-n or n-i-p photodiodes .

36. The flatbed scanner according to claim 33, wherein the photodetectors (602) are organic photodetectors.

37. The device in claim 33, wherein the two-dimensional non- pixelated light source (508) is a light source comprising: a second substrate, and a light source (510) edge-coupled into said second substrate .

38. The flatbed scanner according to claim 33, wherein the two-dimensional non-pixelated light source (608) is an organic light emitting diode (OLED) comprising: a second substrate (300); a first electrode (302) disposed over the second substrate; one or more organic layer (s) (304) disposed over the first electrode; and a second electrode (306) disposed over the organic layer .

39. A flatbed scanner having a two-dimensional image sensor, the flatbed scanner comprising: a flatbed scanner housing for housing a plurality of flatbed scanner components including a two-dimensional image sensor; the two-dimensional image sensor comprising: a first substrate,

a two-dimensional array of photodetectors (702) disposed over said first substrate, and a non-pixelated OLED disposed over the two- dimensional array of photodetectors (706), the OLED comprising: a first electrode (302), one or more organic layer (s) (304) disposed over said first electrode, and a second electrode (306) disposed over said organic layer . where the non-pixelated OLED is at least partially transparent to its own emission.

40. The flatbed scanner according to claim 39, wherein pixilated color filters (704) are disposed over the array of photodetectors (702) and the OLED (706) is disposed over said pixilated color filters .