Abstract:
The present invention provides a projecting apparatus including a driving portion which receives a predetermined signal to output a driving signal, a separating portion which separates a video signal into a horizontal synchronous signal and a vertical synchronous signal, a color correcting portion which adds a color correction to the horizontal synchronous signal and vertical synchronous signal to generate and output a color correction signal, multiple projection cathode ray tubes which receive the driving signal and the color correction signal to emit a light which is projected in accordance with the driving signal and which is subjected to the color correction by the color correction signal, and a display portion which receives the projected light to display a video. This configuration corrects the unevenness of colors from the multiple projection cathode ray tubes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-357865, filed Oct. 17, 2003, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a projecting apparatus using a projection lamp, and in particular, to a projecting apparatus and a method of projection in which loads on a projection lamp are estimated in accordance with the level of an output coefficient to accurately predict the lifetime of the lamp.  
         [0004]     2. Description of the Related Art  
         [0005]     A large number of digital video apparatus have recently been popularized. These digital video apparatuses include, for example, projection apparatuses such as liquid crystal projectors and DLP projectors which employ a light source lamp. The light source lamp utilized in such a liquid crystal projector has a lifetime indicated by an integrated usage time indicating the time for which the lamp remains available. Light source lamps the integrated usage time of which is close to or exceeds the lamp lifetime may have their characteristics degraded or may become defective and unavailable. These lamps are thus unreliable.  
         [0006]     As a conventional technique (Jpn. Pat. Appln. KOKAI Publication No. 2002-287243) for such an optical disk apparatus, a projector apparatus has been disclosed which automatically estimates the integrated usage time for the light source lamp and which urges, on a screen, a user to change the lamp in accordance with the lifetime of the lamp. Thus, the user can determine the lamp lifetime at an optimum time to change the lamp. Accordingly, the capabilities of the lamp can be fully provided.  
         [0007]     This conventional technique recognizes that a variation in projection angle may result in uneven colors, which should be electrically resolved. However, it does not specifically disclose what circuit should be used or how a correction signal should be generated. Thus, this invention clarifies the object but fails to disclose a technique sufficient to allow those skilled in the art to achieve the object.  
         [0008]     That is, the light source lamp of the projector apparatus shown in the above conventional technique has a function to switch the quantity of light as required. In this connection, it is known that loads on the lamp depend on the quantity of light. Accordingly, if a 100% quantity of light is not always projected but a different quantity of light, for example, a 50% quantity of light is used, the method according to the conventional technique cannot obtain the accurate estimated amount of loads on the light source lamp. Thus, disadvantageously, the apparatus may urge the lamp light source to be changed even though it is not fully exhausted.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     An embodiment according to the present invention is a projecting apparatus characterized by comprising a driving portion which outputs a driving current in association with a control signal containing an output coefficient, a lamp portion which receives the driving current from the driving portion to project light, and a control portion which supplies the driving portion with a control signal containing the output coefficient and which estimates loads on the lamp portion in accordance with the output coefficient and an operation time of the control signal. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0010]      FIG. 1  is a block diagram showing an example of the configuration of a projecting apparatus according to the present invention;  
         [0011]      FIGS. 2A and 2B  are schematic views showing an example of the appearance of the projecting apparatus according to the present invention;  
         [0012]      FIG. 3  is a view illustrating an example of an optical configuration of the projecting apparatus according to the present invention;  
         [0013]      FIG. 4  is a flow chart showing an example of a process of estimating the lifetime of a lamp in the projecting apparatus according to the present invention;  
         [0014]      FIGS. 5A and 5B  are views illustrating an example of display provided by the projecting apparatus according to the present invention; and  
         [0015]      FIG. 6  is a timing chart showing an example of a grid signal from a blue projection cathode ray tube according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     With reference to the drawings, a detailed description will be given of an embodiment of a projecting apparatus according to the present invention. The projecting apparatus according to the present invention determines the lifetime of the light source lamp on the basis of the time for which the light source lamp has been used as well as an output coefficient for the light source lamp.  FIG. 1  is a block diagram showing an example of the configuration of the projecting apparatus according to the present invention.  FIGS. 2A and 2B  are schematic views showing an example of the appearance of the projecting apparatus according to the present invention.  FIG. 3  is a view illustrating an example of an optical configuration of the projecting apparatus according to the present invention.  FIG. 4  is a flow chart showing an example of a process of estimating the lifetime of the lamp in the projecting apparatus according to the present invention.  FIGS. 5A and 5B  are views illustrating an example of display provided by the projecting apparatus according to the present invention.  FIG. 6  is a timing chart showing an example of a grid signal from a blue projection cathode ray tube according to the present invention.  
         [0000]     Projecting Apparatus according to Present Invention  
         [0000]     (Construction)  
         [0017]     A projecting apparatus  1  according to the present invention has an RGB component terminal  11 , a Y/CB/CR terminal  12 , an A/D converter  15  that receives these terminals, a scaler  16  that receives an output from the A/D converter  15 , a CVBS terminal  13 , an S-VIDEO terminal  14 , a video decoder  17  that receives outputs from these terminals, a progressive converting portion  18  that receives an output from the video decoder  17 , and an SDRAM  19  connected to the progressive converting portion  18 . Further, a component signal from the A/D converter  15  is supplied to the progressive converting portion  18 . An RGB signal from the progressive converting portion  18  is supplied to the scaler  16 .  
         [0018]     Furthermore, outputs from the scaler  16  which correspond to an R signal, a G signal, and a B signal, respectively, are supplied to respective digital gamma correction portions  20 . Outputs from the digital gamma correction portions  20  are supplied to respective sample hold/DA converters  22 . Outputs from the sample hold/DA converters  22  are provided to liquid crystal panels  23 R,  23 G, and  23 B.  
         [0019]     Further, an output from the scaler  16  is supplied to a timing generator  24 . The timing generator  24  supplies synchronous signals to the liquid crystal panels  23 R,  23 G, and  23 B.  
         [0020]     The projecting apparatus  1  has a control section  32  that controls the above operations. The control section  32  has a function of a lamp load integration portion, described later, to estimate loads on a lamp. The control section  32  has a memory and supplies a control signal to a lamp driver  34 . The lamp driver  34  supplies a projection lamp  35  with a driving current with an output coefficient.  
         [0021]     The projecting apparatus  1  has an appearance such as the one shown in  FIGS. 2A and 2B . The front view in  FIG. 2A  shows a projection lens  36 . The rear view in  FIG. 2B  shows a projection lamp unit  35   a  to be changed.  
         [0022]     The projection lamp unit  35   a  of the projecting apparatus  1  has the projection lamp  35  inside, which is shown by the optical configuration in  FIG. 3 . The projection lamp  35  is placed near an optical unit  41 . Light emitted by the optical unit  41  passes through a multilens  42  and a convex lens  43  provided adjacent to the multilens  42 . The light then passes through or is reflected by a transmission mirror and is then transmitted through the liquid crystal panels  23 R,  23 G, and  23 B. Thus, the light emitted by the projection lamp  35  and containing a video is applied through the projection lens  36 . Consequently, a video image is formed on a screen or the like (not shown) on which the light is projected.  
         [0000]     (Operations)  
         [0023]     Now, operations of the projecting apparatus  1  will be described in detail with reference to the drawings. A video signal is supplied to the RGB component terminal  11 , the Y/CB/CR terminal  12 , the CVBS terminal  13 , or the S-VIDEO terminal  14 . Then, one input is selected under the control of the control portion  32 . If a component signal is inputted via the RGB component terminal  11  or the Y/CB/CR terminal  12 , the A/D converter  15  converts it into a digital signal. If a signal is inputted through the CVBS terminal  13  or the S-VIDEO terminal  14 , the video decoder  17  decodes it. Then, the progressive converting portion  18  converts the decoded signal into an RGB signal and outputs the RGB signal to the scaler  16 . The scaler  16  converts the RGB signal in accordance with the size of each of the liquid crystal panels  23 R,  23 G, and  23 B. The scaler  16  then supplies the converted signal to the digital gamma correction portion  20  for the respective color signals. The digital gamma correction section  20  executes gamma corrections to adjust the linearity of the video information to obtain video signals and then supplies the signals to the respective digital color unevenness correction portion  21 . The video signals subjected to color unevenness corrections are supplied to the sample hold/DA converter  22 . The sample hold/DA converters  22  subject the video signals to DV conversions and supplies the converted signals to the liquid crystal panels  23 R,  23 G, and  23 B, respectively. In accordance with synchronous signals from the timing generator  24 , the liquid crystal panels  23 R,  23 G, and  23 B display videos corresponding to the video information, on respective liquid crystal screens.  
         [0024]     On the other hand, upon receiving an operation signal from an operation portion  31 , the control portion  32  supplies a control signal to the lamp driver  34  in order to provide a lamp output with an output coefficient of 1 (100%). Then, the projection lamp  35  projects light in response to a driving signal from the lamp driver  34 .  
         [0025]     Subsequently, the videos for the respective color signals are displayed on the liquid crystal screens as follows: as shown in  FIG. 3 , light from the projection lamp  35  is projected into an optical unit  41 , passes through the multilens  42  and the convex lens  43 , then passes through or is reflected by the transmission mirror, and is subsequently applied to the liquid crystal panels  23 R,  23 G, and  23 B as projected light. Then, the projected light with the video is applied through the projection lens  36  to form and display the video on the screen or the like (not shown).  
         [0000]     (Lamp Load Integration Process)  
         [0026]     Now, with reference to the flow chart shown in  FIG. 4 , an example of display shown in  FIGS. 5A and 5B  and provided by the projecting apparatus, and the timing chart in  FIG. 6 , a detailed description will be given of a process of estimating loads on the lamp in the projecting apparatus, which process is a characteristic of the present invention. The projecting apparatus  1  according to the present invention determines the lifetime of the projection lamp  3  in accordance with the output coefficient of the projection lamp  3 . Specifically, the projection lamp  35  may not only provide a 100% output but also apply a suppressed output, for example, a 50% or 75% output. This saves power and serves to prolong the lifetime of the lamp. In this case, High (a 100% output) and Low (a 50% output) will be described by way of example.  
         [0027]     In this case, as shown in the timing chart in  FIG. 6 , for a timing T 1  for a timer  1 , which corresponds to a process of estimating loads on the lamp which process does not take the output coefficient of the projection lamp into account, if High lasts 1,000 hours, Low lasts 1,000 hours, and then High lasts 1,000 hours, all estimations are carried out using a coefficient of 1 to determine that a total of 3,000 H of lifetime has been spent. Even in this case, for a timing T 2  for a timer  2 , which corresponds to a process of estimating loads on the lamp which process is executed by the control portion  32  of the projecting apparatus  1  according to the present invention taking the output coefficient of the projection lamp into account, integrated loads on the lamp portion are measured using a coefficient of 0.5 for the 1,000 hours of Low. Thus, the control section  32  recognizes a total of 2,500 hours of integrated loads on the projection lamp. Consequently, the control section  32  can measure a value for the loads actually imposed on the lamp portion to accurately determine the lifetime of the lamp portion.  
         [0028]     Specifically, in the flow chart shown in  FIG. 4 , when the projecting apparatus  1  is activated in response to an operation of the operation portion  31 , the control portion  32  estimates loads on the lamp in accordance with the output coefficient of the lamp (S 11 ). Specifically, the usage time of the lamp portion is estimated as a lamp load using a coefficient of 1 for High (a 100% output) and a coefficient of 0.5 for Low (a 50% output). This makes it possible to accurately determine integrated loads on the projection lamp as shown in connection with the timing T 2  for the timer  2  in the timing chart of  FIG. 6 . Then, an estimating process is executed using, for example, a coefficient of 0.75 for a 75% output or a coefficient of 0.25 for a 25% output.  
         [0029]     Then, if an instruction given by a user using the operation portion  31  urges the usage time of the lamp to be displayed, then for example,  35 H or  40 H is displayed for 100% or 50% usage, respectively, as shown by an icon  51  in  FIG. 5A  on the basis of the integrated time accumulated in a memory  33 . Alternatively and suitably, a 50% output is treated as a time obtained through a multiplication by a coefficient of 0.5 and is displayed as H=35+40×2=55 H.  
         [0030]     Then, it is determined whether or not the integrated loads on the lamp portion exhibit a value corresponding to a given lamp lifetime. Suitably, if it is determined that this value has been reached (S 14 ), the control portion  32  then uses an icon to display “Please change lamp unit” or the like as shown in  FIG. 5B  (S 15 ).  
         [0031]     Moreover, a change of the projection lamp  35  is suitably detected by a sensor (not shown) provided in the lamp unit  35   a  or in the main body of the projecting apparatus  1 . Thus, when a change of the lamp is automatically recognized (S 16 ), the integrated lamp load is suitably automatically reset (S 17 ). However, after the lamp has been changed, the user may suitably manually reset the timer via the operation portion  31 .  
         [0032]     To provide time information on the lamp lifetime, it is possible to provide one value by default or to provide the lamp unit  35   a  with a sensor to determine the lifetime. Alternatively, the user may provide lifetime information to the memory  33  or the like via the operation portion  31 .  
         [0033]     Alternatively, the control portion  32  may suitably determine the remaining available time (lifetime) on the basis of the current integrated lamp load and the given lamp lifetime to display an available time for each of multiple output coefficients for the lamp portion, on the screen of the display portion. Specifically, if 1,000 hours remain, the control portion  32  executes calculations to display 1,000 hours for a 100% output or 2,000 hours for a 50% output on the screen. This enables the user to make an intuitive choice.  
         [0034]     The above projecting apparatus estimates the loads on the light source lamp on the basis of not only the usage time of the light source lamp but also the output coefficient such as 100% or 50%. Specifically, calculations are executed so that even if the lamp has been used for 10 hours, if the output coefficient is 50%, the loads on the light source lamp are assumed to be integrated only for 5 hours for an output coefficient of 100%. This enables the lifetime of the lamp to be accurately predicted also taking the value of the output coefficient into account. Further, by accurately predicting the set lifetime of the light source lamp, it is possible to examine the usage of the light source lamp for the rest of the lifetime also taking the output coefficient of the lamp into account. Specifically, on the basis of the given lifetime of the light source lamp and the integrated loads on the light source lamp, it is possible to show, for example, that the lamp can be used for five more hours if the output coefficient is 100% or for ten more hours if the output coefficient is 50%.  
         [0035]     Those skilled in the art can implement the present invention on the basis of the various embodiments described above. However, many variations of these embodiments occur easily to those skilled in the art and can be applied as various embodiments without any inventive abilities. Therefore, the present invention covers a wide range consistent with the disclosed principles or novel features. The present invention is thus not limited to the above embodiments.