Abstract:
The image reading device of the present invention is an image reading device comprising a reading unit reading an image of an original document, a clear plate disposed between the original document and the reading unit, a clear photoemitting layer included in the clear plate and having a plurality of emitting areas, a clear input sensor included in the clear plate and outputting a two-dimensional position of a pushed place on the clear plate and an controller displaying an operation panel on the clear plate using the clear photoemitting layer and receiving operations to the operation panel.

Description:
RELATED APPLICATIONS 
     This application is based on application No. 2005-200486, filed in Japan, the contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image reading device that is included in a copying machine or the like and reads images of original documents, as well as to an image forming apparatus having such device, and more particularly to an image reading device that also functions as an operation panel and to an image forming apparatus having such device. 
     2. Description of the Prior Art 
     An image forming apparatus such as a copying machine, for example, conventionally includes an image reading device that reads images of original documents. An image reading device generally includes a platen glass on which the original document is placed, a photoelectric conversion element or the like that receives the light emitted to the original document surface via the platen glass and reflected therefrom and converts this light into electric signals. In addition, an image forming apparatus includes an operation panel, and the user of the apparatus inputs various desired operation parameters via this operation panel. For example, in a copying operation carried out using a copying machine, copied images are formed based on the image data read by the image reading device and in accordance with the input copying operation parameters. 
     Such an operation panel is often disposed on the front side or top side of the apparatus to enable easy use thereof by the user. Furthermore, because the operation panel must be made compact due to space limitations, while the number of display items has increased with the increasing number of functions incorporated in image forming apparatuses in recent years, a layered system or the like is often used for the display. However, it is still sometimes difficult to determine the relationship between the original document size and the actual print size, or the setting of printing orientation. In view of this problem, Japanese Laid-Open Patent Applications H5-40317 and H7-84233 disclose copying machines having a platen glass comprising a photo-transmitting liquid crystal panel. According these technologies, information such as the position and size of the original document can be displayed on the liquid crystal panel in a way that is easy to understand. 
     However, because a liquid crystal panel is used in both of the conventional technologies mentioned above, the viewing angle is narrow, and depending on the position or the height of the user, the display may be difficult to see. In addition, the problem exists that because liquid crystal is not a self-illuminating display, it requires light, which leads to a complex apparatus construction. Furthermore, because a liquid crystal panel generally uses a deflecting plate and the panel thickness is in the order of several millimeters due to the considerable thickness of the liquid crystal cells, the amount of light declines significantly when light is transmitted through the panel. As a result, in an image reading device that illuminates an original document from below the platen glass using a lamp or the like and inputs the reflected light to a photoelectric conversion element, noise may increase and lead to a deterioration in image quality. 
     Furthermore, with an apparatus in which instructions are input via the operation panel while the user views the display thereon, as in the case of the technology disclosed in the Japanese Laid-Open Patent Application H7-84233 mentioned above, while detailed instructions can be provided, the buttons and the like used for input purposes tend to become small, which may render the apparatus less easy to use. Moreover, if letters or the like are to be added to the printing, it is difficult to accurately input such letters in the desired positions, resulting in a number of input attempts while viewing the display. 
     SUMMARY OF THE INVENTION 
     The present invention was devised in order to resolve the problems with the image reading device of the conventional art and the image forming apparatuses that includes an image reading device of this type. An object of the present invention is to provide an image reading device that takes up a small amount of space and is easy to use, as well as to an image forming apparatus that includes such device. 
     In order to attain this object, the image reading device of the present invention comprising a reading unit reading an image of an original document, a clear plate disposed between the original document and the reading unit, a clear photoemitting layer included in the clear plate and having a plurality of emitting areas, a clear input sensor included in the clear plate and outputting a two-dimensional position of a pushed place on the clear plate and an controller displaying an operation panel on the clear plate using the clear photoemitting layer and receiving operations to the operation panel. 
     According to the image reading device of the present invention, images of an original document placed on the clear plate is read by the reading unit. Because the clear plate has a clear photoemitting layer, an operation panel can be displayed on the clear panel via control by the controller. In addition, because the clear plate has a clear input sensor, operations to the operation panel can be received by the controller. Therefore, because the clear plate on which the original document is placed can be used as the operation panel, it is no longer necessary to set aside a large space for an operation panel and therefore space conservation can be achieved. 
     The present invention also comprises an image forming apparatus comprising a reading unit reading an image of an original document, a clear plate disposed between the original document and the reading unit, a clear photoemitting layer included in the clear plate and having a plurality of emitting areas, a clear input sensor included in the clear plate and outputting the two-dimensional position of a pushed place on the clear plate, an controller displaying an operation panel on the clear plate using the clear photoemitting layer and receiving operations to the operation panel and an image forming unit forming the image read by the reading unit on a recording medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is an external view showing the basic construction of a copying machine pertaining to an embodiment; 
         FIG. 2  is a cross-sectional view showing the basic construction of an image reading device pertaining to the embodiment; 
         FIG. 3  is a cross-sectional view showing the basic construction of a platen glass pertaining to the embodiment; 
         FIG. 4  is an explanatory drawing showing an example of the driving method for a photoemitting layer; 
         FIG. 5  is an explanatory drawing showing the basic construction of a pressure sensor; 
         FIG. 6  is an explanatory drawing showing the operation of the pressure sensor; 
         FIG. 7  is an explanatory drawing showing the basic construction of an original document size detection sensor; 
         FIG. 8  is an explanatory drawing showing an example of display contents; 
         FIG. 9  is an explanatory drawing showing an example of display contents; 
         FIG. 10  is an explanatory drawing showing an example of display contents; and 
         FIG. 11  is an explanatory drawing showing an example of display contents. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom. 
     An embodiment is described below in which the present invention is applied in a copying machine having an image reading device that reads the images of original documents. 
     The copying machine  100  of this embodiment has an image reading device  1  as shown in the external view of  FIG. 1 . The copying machine  100  further includes an automatic document feeder  110  at the top part thereof, as well as a printing unit  120 , a paper supply unit  130  and a manual paper supply tray  140 , which are disposed in this order from the top. The copying machine  100  also includes an internal storage device  150  that stores various image data, operation parameter values and the like. The top surface of the printing unit  120  also serves as an ejection tray. 
     The image reading device  1  reads the images of original documents, and the image data read thereby can be accumulated in the storage device  150 . The image reading device  1  is described in detail below. The automatic document feeder  110  feeds the original document to the image reading device  1  one sheet at a time. It may also have a function to flip over the sheet. The printing unit  120  forms an image on a sheet of paper supplied from the paper supply unit  130  or the manual paper supply tray  140  using the public-domain electrophotographic method based on the image data read by the image reading device  1 . Alternatively, image formation may be carried out based on image data accumulated in the storage device  150  or received from an external device. 
     The image reading device  1  of this embodiment has a platen glass  10  on which an original document S is placed on the top surface of the reading unit  2  as shown in  FIG. 2 . A controller  3  that controls the platen glass  10  is connected thereto. The reading unit  2  reads the image of the original document placed on the platen glass  10 , and has a first slider unit  11 , a second slider unit  12 , a lens  13  and a photoelectric conversion element  14 . Furthermore, the first slider unit  11  includes a light source  15 , a reflecting plate  16  and a first reflecting mirror  17 , while the second slider unit  12  includes a second reflecting mirror  18  and a third reflecting mirror  19 . 
     With this image reading device  1 , the light emitted from the light source  15  illuminates the original document S directly or via the reflecting plate  16 . The light reflected from the original document S is reflected off the first reflecting mirror  17 , second reflecting mirror  18  and third reflecting mirror  19 , is reduced by the lens  13 , and finally forms an image on the light-receiving surface of the photoelectric conversion element  14 . The components other than the platen glass  10  are generally used in reduction image reading devices and will not be explained herein. 
     As shown in the partially expanded view in  FIG. 3 , the platen glass  10  of this embodiment comprises a transparent organic EL (electroluminescence) display  20  and a pressure sensor  30 , which are layered together. The use of a transparent organic EL display enables the platen glass to be formed thinner than when a liquid crystal panel is used and minimizes the amount of light reduction. As a result, original documents can be read while maintaining high image quality. The transparent organic EL display  20  comprises a glass substrate  21 , a transparent electrode layer  22 , an EL photoemitting layer  23 , a cathode layer  24 , a transparent electrode layer  25  and cover glass  26 . The EL photoemitting layer  23  is a light source formed of a transparent organic EL element using an organic compound, and emits light by re-combining electrons of an electron carrier layer and electron holes of a hole carrier layer within the EL photoemitting layer  23 . The transparent electrode layers  22 ,  25  comprise transparent electrodes using indium-tin oxide (ITO) compound and serves to convey electricity to the EL photoemitting layer  23 . 
     Voltage impressed to the transparent electron layers  22 ,  25  is controlled by drive circuits  41 ,  42  that are disposed along the edges of the platen glass  10 , respectively, as shown in  FIG. 4 . These transparent electrode layers  22 ,  25  are disposed such that the electrodes of respective layers are disposed at a right angle to each other with the EL photoemitting layer  23  and cathode layer  24  therebetween, as shown in  FIGS. 3 and 4 . The band-shaped electrodes of the transparent electrode layer  22  that are disposed in a lateral fashion in the drawings are selectively controlled by the drive circuit  41  while the band-shaped electrodes of the transparent electrode layer  25  that are disposed in a longitudinal fashion in the drawings are selectively controlled by the drive circuit  42 . The areas at which these electrodes of the transparent electrode layers  22  and  25  cross each other comprise photoemitting units  27 , which are disposed in a lattice configuration in the platen glass  10 . In other words, because each photoemitting unit  27  is driven by the drive circuits  41 ,  42  to turn ON or OFF, the EL photoemitting layer  23  can be caused to emit light at the desired areas. These drive circuits  41 ,  42  are disposed outside the image reading range and are controlled by the controller  3 . 
     The pressure sensor  30  comprises, as shown in  FIG. 3 , a transparent conductive film  31  disposed on the cover glass  26 , spacers  32 , a transparent conductive film  33  and a film  34 , which are layered together. Transparent X-axis electrodes  44  and Y-axis electrodes  45  are formed in the transparent conductive films  31 ,  33 , respectively, as shown in  FIG. 5 , and are usually separated from each other by the spacers  32 . When pressure is exerted on the pressure sensor  30  from above, parts of the transparent conductive films  31  and  33  come into contact with each other as shown in  FIG. 6 . As a result, the X-axis electrodes  44  and Y-axis electrodes  45  come into contact and a current flow. Here, the precise location that was pressed can be detected by measuring the voltage division ratio created by the resistance values for the transparent conductive films  31 ,  33 . The result of detection by the pressure sensor  30  is input to the controller  3 . 
     Dot spacers comprising granular insulators are generally used as the spacers  32  used in the pressure sensor  30 , and highly durable and relatively large spacers (having a diameter of approximately 80 μm) are used in this embodiment. However, where it is required that the display contain no observable dots, spacers having a diameter of approximately 50 μm may be used. In addition, in devices that requires more specific positioning via the use of a more precise input tool such as a pen or the like instead of a finger, spacers having a smaller diameter of 30 μm or less may be used. 
     Multiple original document size detection sensors  50  are disposed at prescribed positions below the platen glass  10 , as shown in  FIG. 7 . Each original document size detection sensor  50  has a photoemitting surface  51  and light-receiving surface  52 , and the light emitted from the photoemitting surface  51  and reflected by the original document is received by the light-receiving surface  52 . When the light is received, the distance to the object can be measured based on the angle of incidence to the light-receiving surface  52 . In this embodiment, it is determined, based on whether or not an object (comprising an original document here) falls within a prescribed threshold range, whether or not an original document is placed there. Multiple original document size detection sensors  50  are placed within the reading range of the platen glass  10 , and after an original document is placed on the platen glass  10 , the results of detection by the original document size sensors  50  are aggregated prior to reading in order to detect the size of the original document in advance. The results of detection by the original document size sensors  50  are input to the controller  3 . 
     The processing to read the image of the original document S using the image reading device  1  of this embodiment will now be explained below. This processing is performed mainly by the controller  3 . In the description below, an explanation is provided based on the image reading device  1  included in a copying machine. First, as shown in  FIG. 8 , longitudinal and lateral standard scales  61 , a paper size frame  62  conforming to the currently set paper supply cassette, a copying setting display area  63 , an operation button area  64  and the like are displayed on the platen glass  10 . This prevents such errors as placement of an original document on the wrong area. Buttons to set the expansion/reduction rate and the number of copies to be made and the copy mode are displayed in the copy settings display area  63  and to instruct that copying operations be started or stopped, are displayed in the operation button area  64 . When an area within the operation button area  64  is pressed by the finger or the like, the location of the area pressed is detected by the pressure sensor  30  and prescribed setting change is carried out accordingly. 
     When the original document S is set on the platen glass  10  by the user, the paper size frame  62  becomes hidden, as shown in  FIG. 9 . Therefore, the size of the original document is first detected by the original document size detection sensors  50 , and the original document size  65  is displayed outside the original document range. Because the original document size  65  is displayed outside the original document range, the display is not hidden by the original document, making the apparatus easy to use. Where a paper size that matches the size of the original document is not set in the paper supply cassette, the smallest paper size that accommodates the entire original document may be displayed together with the paper size frame  62  therefor. Various setting instructions input by the user from the operation button area  64  from the user are accepted in this state, and when the reading start button is pressed, reading is begun. 
     During reading, the platen glass  10  is maintained in a transparent state. In other words, the drive circuits  41 ,  42  do not cause any photoemitting units  27  to emit light. Therefore, the image reading device  1  works in the same way as a general reduction optical image reading device, and the image of the original document S is input as image data S 1  by the photoelectric conversion element  14 . 
     The image data S 1  read of the original document is displayed on the platen glass  10  as shown in  FIG. 10 . The user can view this display by removing the original document S from the platen glass  10 . When this is done, the paper size frame  66  set via the current settings is simultaneously displayed. The user can now instruct various setting changes directly on the display by operating the copy settings display area  63  and operation button area  64  while viewing the read original document image. For example, it is acceptable if various setting options are displayed as buttons in the operation button area  64  by pressing the setting items desired to be changed in the copy settings display area  63 . 
     Furthermore, letters and images may be added to the image data using a software keyboard on the platen glass  10  or by enabling input using an input pen  67 . It is acceptable if handwritten letters are recognized and corrected into standard style letters. In addition, the image residing within a prescribed area range may be deleted by using an eraser pen or by having the range recognized. In addition, image areas may be designated and moved or the colors thereof may be changed. 
     When the image data to be output is displayed on the platen glass  10 , the user presses the ‘OK’ button in the operation button area  64 . This causes the currently-displayed image to be formed on designated paper. 
     Although the original document holder that covers the platen glass  10  was not explained in the description given above, such a holder is generally of a size that covers the entire platen glass  10  in a copying machine or the like. This is because the original document holder prevents the original document S from being displaced during reading and prevents the light emitted from the light source  15  for image reading from striking the eyes of the user. In contrast, the image reading device  1  may include an original document holder  70  that matches the reading range and a platen glass  10  that is larger than the reading range as shown in  FIG. 11 . 
     In this way, because the copy settings display area  63  and operation button area  64  can be displayed outside the reading range of the platen glass  10 , various instructions can be input with the original document holder  70  closed. Once reading of the original document is completed, the original document holder  70  can be opened, enabling the original document S to be removed and the display on the platen glass  10  to be viewed. 
     As described above in detail, with the copying machine  100  of this embodiment, because a transparent organic EL display  20  is used as the platen glass  10  of the image reading device  1 , the platen glass  10  can be made transparent during image reading. Because the organic EL display  20  can be made thin in comparison with a liquid crystal panel, high-quality image reading is obtained. Furthermore, the read image data can be displayed on the platen glass  10  after reading. In addition, because the platen glass  10  of this embodiment includes a pressure sensor  30 , it can also function as an operation panel. User operation even during viewing of the actual-size image data is accordingly enabled, providing good operability. Therefore, as a whole, space conservation can be achieved while easy operability is obtained via the image reading device  1  that reads high-quality images and the copying machine  100  that incorporates the image reading device  1 . 
     This embodiment is a mere example, and does not limit the present invention in any way. Therefore, the present invention can naturally be improved and/or modified in various ways within the essential scope thereof. 
     For example, the EL photoemitting layer  23  of the image reading device  1  may comprise an inorganic EL light source or an organic EL light source. 
     In addition, while the embodiment described above uses as the driving method the passive-matrix method in which the drive circuits are externally mounted, it is acceptable if the active-matrix method in which switching elements are added to the pixels is used. 
     Furthermore, for example, the embodiment described above enables various types of editing of the read image, but it is acceptable if a storage device is included in the image reading device such that the same types of processing can be performed to an image retrieved from the storage device. It is also acceptable if various types of editing are enabled with regard to image data sent from an external device such as a computer.