Patent Abstract:
A portable x-ray viewer is configured as a clipboard. The clipboard configuration makes the portable x-ray viewer easy to handle by doctors and other medical personnel. Since the viewer is portable, the number of required x-ray viewers in a doctor&#39;s office or a medical facility is greatly reduced, thus reducing the overall cost. In addition, the portable x-ray viewer is provided with an automatic control for controlling the viewer. In particular, in accordance with an important aspect of the invention, the viewer is automatically turned on when an x-ray is inserted and is automatically turned off when the x-ray is removed. As such, use of the x-ray viewer is facilitated for medical personnel and also eliminates the problem of premature burnout of the display or lamp when the x-ray viewer is left on for extended periods of time.

Full Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a film viewer and more particularly to a portable film viewer configured as a clipboard with an automatic control circuit which automatically turns the viewer on when a hard copy film is inserted and automatically turns the viewer off when the film is removed. 
   2. Description of the Prior Art 
   Film viewers, such as x-ray viewers, are generally known in the art. Such x-ray viewers are known to be used in the medical industry by medical personnel to view x-ray films. Examples of such x-ray viewers are disclosed in U.S. Pat. Nos. 4,118,654; 4,510,708; 4,908,876; 6,031,516; 6,088,941; 6,208,437; 6,462,868; and 6,548,823. X-ray viewers are also known for viewing digital x-rays. U.S. Pat. Nos. 6,031,516 and 6,462,868 disclose dual-function x-ray viewers that are configured to view both hard copy x-ray films as well as digital x-rays. 
   In the medical industry, hard copy x-ray films are predominately used. Such x-ray film viewers are normally wall-mounted and include a lightbox. One known conventional viewer includes a light source or lamp, a reflector plate, and a diffuser plate. The lamp and the reflector plate are disposed adjacent a rear wall of the light box. The diffuser plate forms the front wall of the lightbox. The diffuser plate causes relatively uniform light to be distributed across its surface to allow relatively accurate reading of the x-ray film. An example of such an x-ray viewer is disclosed in U.S. Pat. Nos. 4,118,654 and 4,510,708. 
   There are several problems with such known x-ray viewers. First, in many medical applications, such as doctors&#39; offices, such x-ray viewers are required in each of the patient examination rooms—especially in patient examination rooms of orthopedic surgeons. By having an x-ray viewer in the patient examination rooms, the orthopedic surgeon is able to show patients the exact nature of their problem. However, such x-ray viewers are relatively expensive. Thus, separate x-ray viewers in each patient examination room can be costly for a doctor. 
   Another problem with known x-ray viewers is that the light or display must be controlled manually by the medical personnel, which is cumbersome. Additionally, medical personnel are known to leave the lamp or display on for extended periods of time. Accordingly, the lamps and displays are known to burn out prematurely, thus increasing the cost to the medical facility. Thus, there is a need to reduce the cost of such x-ray viewers. 
   SUMMARY OF THE INVENTION 
   Briefly, the present invention relates to a portable film viewer configured as a tabletop clipboard device with a handle. The handle and the clipboard configuration make the portable film viewer easy to handle by doctors and other medical personnel. Since the viewer is portable, the number of required film viewers in a doctor&#39;s office or a medical facility is greatly reduced, thus reducing the overall cost. In addition, the portable film viewer is provided with an automatic control circuit for controlling the light source in the viewer. In particular, the automatic control circuit automatically turns the film viewer on when a hard copy film is inserted and automatically turns off the film viewer when the film is removed. As such, use of the film viewer is facilitated for medical personnel and also eliminates the problem of premature burnout of the display or lamp. 

   
     DESCRIPTION OF THE DRAWINGS 
     These and other advantages of the present invention will be readily understood with reference to the following drawings and attached specification wherein: 
       FIG. 1  is a perspective view of a portable film viewer in accordance with the present invention. 
       FIG. 2  is another perspective view, illustrating a top portion of the portable film viewer, formed with a slot for carrying a marking pencil. 
       FIG. 3  is an exploded perspective view of the film viewer in accordance with the present invention. 
       FIG. 4A  is a front view of the film viewer in accordance with the present invention. 
       FIG. 4B  is a bottom view of the film viewer in accordance with the present invention. 
       FIG. 4C  is a left side view of the film viewer in accordance with the present invention. 
       FIG. 4D  is a top view of the film viewer in accordance with the present invention. 
       FIG. 4E  is a right side view of the film viewer in accordance with the present invention. 
       FIG. 5A  is a back view of the film viewer in accordance with the present invention. 
       FIG. 5B  is a sectional view of the right side of the film viewer in accordance with the present invention. 
       FIG. 5C  is a detailed view of a portion of the film viewer, illustrating a contact switch and film grip in accordance with the present invention. 
       FIG. 6  is a perspective view of a front portion of the film viewer in accordance with the present invention. 
       FIG. 7  is a perspective view of the back of the film viewer in accordance with the present invention. 
       FIG. 8  is a block diagram, illustrating the electrical connections for the film viewer in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   The present invention relates to a portable film viewer, for example, an x-ray viewer. In order to facilitate handling of the portable film viewer, the device includes a handle and is configured as a clipboard. In addition, a slot for carrying a marking pencil commonly known as a so-called “China marker”. In order to further facilitate use of the film viewer in accordance with the present invention, the film viewer is provided with a control circuit, which automatically turns on the film viewer when an x-ray film or other hard copy film is inserted into a film grip. The automatic control circuit also automatically turns off the film viewer when the hard copy film is removed from the film grip. 
   The portable film viewer is described and illustrated herein for use in medical applications for viewing x-ray films in the medical industry. It is to be understood that the principles of the present invention are also applicable to other applications, such as dental x-rays and industrial x-rays. Furthermore, it is to be further understood that the portable film viewer in accordance with the present invention can also be used with other hard copy films, other than x-ray films. 
   Referring to the drawings, the portable film viewer in accordance with the present invention is generally identified with the reference numeral  20 . As shown in  FIG. 1 , the portable film viewer  20  in accordance with the present invention includes a front panel  22 , a viewing window  24 , and a film grip assembly  26 . The film grip assembly  26  includes a notch  28  for receiving hard copy films (not shown), such as x-ray films. As will be discussed in more detail below, the film grip assembly  26  includes an automatic control circuit for automatically turning on the viewer when hard copy film is inserted therein and shutting the viewer  20  off when the hard copy film is removed. 
   As shown best in  FIGS. 5A and 7 , a handle or knob  27  may be provided to facilitate handling of the device  20 . An exemplary oval knob is illustrated. However, other types of handles are contemplated, such as a circular knob, as well as non-circular knobs or handles of virtually any configuration. The portable film viewer  20  is configured to rest on a flat surface, such as a tabletop, as shown in  FIGS. 1 and 2 . The knob  27  facilitates handling of the viewer  20  when it is not resting on a flat surface. In particular, the knob  27  facilitates a user holding the viewer  20  in one hand and while marking on the film with the other hand. The knob  27  may be configured to either be concealed from view when the film viewer  20  is resting on a flat surface or alternatively exposed. 
   In order to further facilitate the use of the portable film viewer  20 , a transverse slot  30  ( FIG. 2 ) is provided along a top portion of the portable film viewer  20 . The width of the slot  30  is configured to receive a conventional marking pencil  32 , known as a so-called “China marker”. Such marking pencils  32  are often used by medical personnel to highlight portions of an x-ray film. 
   As shown in the Figures, the portable film viewer  20  is configured as a clipboard and is rather compact in size. For example, with reference to  FIGS. 4A through 4E , the portable film viewer  20  may be configured with a length L 1  of around 400 mm and a width W 1  of about 230 mm. With such a configuration, the viewing window  24  may be configured with a length L 2  of about 230 mm and a width of about 190 mm. The overall depth W 3  of the portable viewer  20  may be about 40 mm and have an overall weight of around 18 ounces. 
   The portable viewer  20  may be configured in the shape of a clipboard and formed with a molded plastic housing  34  ( FIG. 3 ). The molded housing  34  includes a front panel  22  configured with the viewing window  24  and a rear panel  36 , as generally shown in  FIGS. 3 ,  5 A, and  7 . 
   The front panel  22  includes a viewing window  24 . A flange  48  is formed on the top of the front panel  22 . A separate top plate  50  forms a portion of the film grip assembly  26 . The top plate  50  is connected in a cantilever configuration to the front panel  22  as shown defining a film receiving slot  51  ( FIG. 1 ). In particular, the top plate  50  is formed with a one or more bosses  38 ,  40 , and  42  on its underside. The bosses  38 ,  40 , and  42  are formed as cylindrical members and project outwardly toward the front panel  22  after assembly. The bosses  38 ,  40 , and  42  are for receiving metal balls  44  and biasing springs  46 . In a normal position, the metal balls  46  are urged against the front panel  22  under the influence of the biasing springs  46 . 
   A microswitch actuator  54  is formed on one end of a lever arm  55  that is coupled to a momentary action microswitch  56  configured as an automatic control circuit. When a hard copy film  60  is inserted into the film grip assembly  26 , the microswitch actuator  54  is depressed which causes the lever arm  55  to change the state of a momentary contact  57  ( FIG. 8 ) within the microswitch  56  to a state opposite to that shown in  FIG. 8 . In a normal position (i.e. when no film inserted into the film grip assembly  26 ) and when the film  60  has been removed from the film grip assembly  26 , the momentary contact  57  returns to a normally open state as shown in  FIG. 8 . Other automatic control circuits can also be used. For example, an optical sensor can alternatively be used and configured to interrupt a light beam when a film is inserted. 
   The back panel  36  forms the base of the portable film viewer  20  and includes a generally C-shaped surface  62  that is configured to enable the portable viewer  20  to rest on a table, cabinet, or the like. A battery compartment  64  may be provided for carrying a battery  66 . An access door  68  may also be provided to allow the battery  66  to be replaced from the bottom of the portable viewer  20 . An on-off switch  70  may also be provided. The on-off switch  70  is located on a side wall  76  of the rear panel  36 . 
   Various types of illumination devices or lamps may be used for the portable film viewer  20 . As shown, and as illustrated herein, an electroluminescent lamp, for example, a model number SH-200-BE, as manufactured by Ping Po Lighting Electronics Factory of TungKuan City, Guangdong, China, may be used for viewing hard copy film, such as x-ray film. Referring to  FIG. 8 , the electroluminescent display  72  may be powered by an inverter  74 , for example, a model no. SH-12-200 manufactured by Shang Hong Factory GuangZhou City, Guangdong, China, and a battery  66 , for example, a nine-volt battery. In one exemplary embodiment, the on-off switch  70  is connected in parallel with the momentary contact  57 . As shown in  FIG. 8 , the position of the momentary contact  57  is in a state as shown in  FIG. 5C  (i.e., an x-ray  60  has been inserted into the film grip assembly  26 , tripping the microswitch actuator  54  and closing the momentary contact  57  of the microswitch  56 ), defining a view mode. When the film  60  is removed from the film grip assembly  26 , the microswitch actuator  54  and thus the momentary contact  57  returns to its normal position. As such, assuming the on-off switch  70  is open as shown in  FIG. 8 , insertion of a film  60  into the film grip assembly  26  causes the momentary contact  57  of the microswitch  56  to close, as shown in  FIG. 8 , thus providing a closed-current path between the battery  66  and the inverter  74 . The inverter  74  converts the nine-volt DC output from the battery  66  to a 120-volt AC output for use with the electroluminescent display  72 . When the film  60  is removed from the film grip assembly  26 , the momentary contact  57  in the microswitch  56  opens, thus disconnecting the positive terminal of the battery  66  from the inverter  74 , which, in turn, turns off the electroluminescent display  72 . 
   The on-off switch  70  may be connected in parallel with the microswitch  56 , as shown in  FIG. 8 . In such a configuration, the on-off switch  70  may be used to connect the battery  66  directly to the inverter  74 , irrespective of the state of the momentary contact  57  of the microswitch  56 . Assuming the momentary contact  57  is open as shown in  FIG. 8 , when the on-off switch  70  is open or off, as shown in  FIG. 8 , the battery  66  is disconnected from the inverter  74 , causing the electroluminescent display  72  to be off. During such a condition, when the on-off switch  70  is closed, the positive terminal of the battery  66  is connected to the inverter  74 , which, in turn, causes the electroluminescent display  72  to be turned on. 
   In alternate embodiments of the invention, the portable film viewer  20  may be provided with an electrical cord (not shown) and an electrical plug for direct connection to a 120-volt AC receptacle. In this embodiment, the battery  66  and the inverter  74  would be eliminated. However, the parallel combination of the microswitch  56  and the on-off switch  70  may be connected in series with a line  1  terminal L 1  of the 120-volt plug, so that the automatic control of the electroluminescent display  72  operates in the same manner as discussed above. 
   Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described above.

Technology Classification (CPC): 8