JP5078447B2 - Projection television - Google Patents

Description

  The present invention relates to a projection television provided with a discharge-type light source unit.

  In a conventional light source projection television, a method of projecting an image on a screen using a semiconductor mirror element that reflects a part of light according to an image signal is known. In such a system, a lamp such as a high-pressure mercury lamp, a metal halide lamp, or a halogen lamp is used as the light source unit.

  Patent Document 1 describes a projection television that includes an optical sensor that detects lighting of a light source unit, a control unit, and a memory unit. In the projection television having this configuration, data processing is performed after a while after the lighting of the light source unit is detected. In this way, data is protected from noise generated from the light source unit immediately after lighting.

  Further, the lamp used as the light source unit of the projection television has a long life and needs to be replaced periodically. Therefore, in a conventional projection television, a method has been proposed in which a predetermined lifetime is counted down immediately after lamp replacement using a time timer, and the value is displayed as the remaining lifetime of the lamp.

JP 2006-3607 A

  However, it is known that the luminance of a lamp used as a light source unit deteriorates with the passage of usage time. Therefore, the conventional projection television has a problem that the brightness of the image projected on the screen becomes darker as the usage time elapses.

  Further, the lifetime of the lamp is not constant and varies from lamp to lamp. Therefore, there is a problem that the remaining life counted by the above-described method is not accurate and is merely a guide.

  The present invention has been made to solve the above-described problems, and prevents the brightness of an image projected on a screen from being darkened with the passage of time of use, and the accuracy of a lamp. The purpose is to display the remaining life.

Projection television according to claim 1 comprises an optical sensor for detecting a light source section for video projection, the luminance of the light source unit, and related to the luminance of the light source unit, associated with the passage of use time, beginning And a memory unit in which a plurality of luminance temporal change patterns ranked from the end to the end are stored. Then, it is sequentially determined whether or not the change of the luminance of the light source unit detected by the optical sensor every predetermined time matches the one time-dependent change pattern of the luminance, and it is determined that they match. In this case, the next time-dependent change pattern on the order of the matched time-dependent change pattern is used from the next determination , and a predetermined correction is added corresponding to the matched time-dependent change pattern. The light source unit is driven while changing the driving voltage of the light source unit.

According to the projection television of the first aspect, it is possible to prevent the brightness of the image projected on the screen from becoming dark as the usage time elapses .

<Embodiment 1>
Before describing the projection television according to the present embodiment, a conventional projection television will be described. FIG. 9 is a schematic diagram showing a configuration of a conventional projection television. The conventional projection TV shown in FIG. 9 is a DLP (Digital Light Processing) type projection TV that projects an image on a screen 8, and includes a ballast unit 1, a control unit 2, a memory unit 3, and an image projection unit. The light source unit includes a lamp 4, a color wheel 5, a light pipe 6, a projection lens 7, and a DMD (Digital Mirror Device) element 18.

  The lamp 4 emits light according to the voltage 9 supplied from the ballast unit 1. The ballast unit 1 controls the voltage 9 supplied to the lamp 4. The ballast unit 1 includes a lamp driving circuit 1a and a ballast control unit 1b. As shown in FIG. 9, the ballast controller 1b controls the lamp driving circuit 1a by transmitting a lamp driving control signal 12 to the lamp driving circuit 1a. The lamp driving circuit 1 a supplies the voltage 9 to the lamp 4 in response to the lamp driving control signal 12. The ballast control unit 1 b is controlled by the control unit 2 by transmitting and receiving a ballast control signal 11 to and from the control unit 2.

  FIG. 10 is a diagram illustrating an example of the voltage 9 supplied to the lamp 4 by the lamp driving circuit 1a. As shown in FIG. 10, the lamp driving circuit 1 a supplies the ignition voltage necessary for the start of lighting of the lamp 4 to the lamp 4 as the voltage 9 under the control of the ballast controller 1 b, and then keeps the luminance of the lamp 4 constant. The drive voltage for maintaining is supplied to the lamp 4 as the voltage 9. In supplying the driving voltage to the lamp 4, if an excessive voltage is continuously supplied to the electrode of the lamp 4, the life of the lamp 4 becomes extremely short. Therefore, the drive voltage is maintained within an appropriate range, for example, within the lamp drive voltage range indicated by the two-dot chain lines in FIG. As shown in FIG. 10, the conventional driving voltage is continuously maintained constant. When the lamp driving circuit 1a supplies a voltage to the lamp 4, the lamp driving circuit 1a transmits a lamp driving detection signal 10 to the ballast controller 1b.

  The color wheel 5 is formed by arranging a plurality of color filters including at least three colors of R (red), G (green), and B (blue). The color wheel 5 is arranged so that light from the lamp 4 passes through one of the plurality of color filters. The color wheel 5 changes the color filter that transmits the light from the lamp 4 by rotating the color filter in accordance with the color wheel control signal 14 transmitted from the control unit 2. Further, the color wheel 5 transmits a color wheel operation detection signal 15 to the control unit 2 in accordance with the rotation operation.

  The control unit 2 controls the memory unit 3 by transmitting and receiving a memory unit control signal 16 to and from the memory unit 3. Information necessary for the control unit 2 to control the DMD element 18 is stored in the memory unit 3.

  The DMD element 18 is a semiconductor mirror element, and is controlled according to a DMD element control signal 19 from the control unit 2. The DMD element 18 receives light transmitted through the color wheel 5 and reflects a part of the light. The reflected light is guided by the light pipe 6, magnified by the projection lens 7, and projected as an image on the screen 8. By performing the above operation in a minute time, the conventional projection television can display a color moving image on the screen 8.

  As described above, in the conventional projection television, the lamp 4 is used as a light source for images projected on the screen 8. FIG. 2 shows, as an example, the simplest change with time in the luminance of the lamp 4. As shown in this figure, in the conventional projection television, the luminance of the lamp 4 deteriorates as the usage time elapses. For this reason, there is a problem that the brightness of the image projected on the screen 8 becomes darker with the use time. In the conventional projection television, a predetermined lifetime is counted down immediately after the lamp 4 is replaced using a time timer, and the value is displayed as the remaining lifetime. However, there is a problem that the remaining life counted by this method is not accurate and is merely a guide.

  Next, the projection television according to the present embodiment that solves such problems will be described. FIG. 1 is a schematic diagram of a projection television according to the present embodiment. As shown in FIG. 1, the projection television according to the present embodiment includes a ballast unit 1, a control unit 2, a memory unit 3, a lamp 4 that is a light source unit for video projection, a color wheel 5, and a light. A pipe 6, a projection lens 7, an optical sensor 17, a DMD element 18, and a display unit 20 are provided.

  The ballast unit 1 includes a lamp driving circuit 1a, a ballast control unit 1b, and a memory unit 1c. In the projection television according to the present embodiment, the configuration that is not newly described below is the same as the conventional configuration, and is given the same reference numeral.

  The optical sensor 17 detects the luminance of the lamp 4. The luminance detected by the optical sensor 17 is transmitted to the control unit 2 as a luminance signal 13. The optical sensor 17 is preferably arranged at a position where the effective luminance of the lamp 4 is not reduced. For example, the optical sensor 17 is preferably arranged at a position where light leaked from the lamp 4 is detected.

  The memory unit 1c stores a plurality of time-varying patterns ordered with respect to the luminance of the lamp 4. In the present embodiment, as shown in FIG. 3, four temporal change patterns 1 to 4 are stored in the memory unit 1c in advance. Then, for example, according to the setting of the user, these four time-varying patterns are ordered and stored in the memory unit 1c.

  In the present embodiment, as an example, a case will be described in which the temporal change pattern 1 → the temporal change pattern 2 → the temporal change pattern 3 → the temporal change pattern 4 are stored in order. As shown in FIG. 3, the luminance correction rates X1 to X4 are set corresponding to the temporal change patterns 1 to 4, respectively. The brightness correction factors X1 to X4 are changed by the user according to the type of the lamp 4 when the user replaces the lamp 4, for example.

  In this embodiment, each time-varying pattern 1 to 4 is used once, and a total of four time-varying patterns are ordered and stored in the memory unit 1c. However, the present invention is not limited to this. It is not a thing. For example, as illustrated in FIG. 4, the time-varying patterns 1 to 4 may be used a plurality of times so that a total of n time-varying patterns are ordered and stored in the memory unit 1c.

In the projection television according to the present embodiment, it is sequentially determined whether the change in luminance of the lamp 4 detected by the optical sensor 17 matches one temporal change pattern. In the present embodiment, first, the brightness of the lamp 4 is detected every time t _k (k = 1, 2,...). Then, a change in the luminance of the lamp 4 in a period including the time t _k is calculated and stored in the memory unit 1c. In the present embodiment, it is assumed that the change in luminance is a value Q _{k obtained} by using a moving average method for time-averaged luminance P _n .

Here, the luminance P _n averaged over time is represented by P _n = (A _n −A _n−1 ) / (t _n −t _n−1 ). In this equation, A _n-1 is the luminance of the lamp 4 at time t _n-1 , and _An is the luminance of the lamp 4 at time t _n . This P _n corresponds to the slope of a straight line in FIG.

Q _k is a period including time t _k, for example, in the _{t kN / 2 ~t k ~t k} + N / 2, a value obtained using the moving average method to the above-described _{P n, Q k = (P} kN _{/ 2} + P _{kN / 2 + 1} +... + P _k-1 + P _k + P _{k + 1} +... + P _{k + N / 2} ) / N. In this way, the brightness of the lamp 4 detected by the optical sensor 17, and calculates a change Q _k of the luminance in a time period including t _k, stores the change Q _k of the luminance memory unit 1c.

In the memory unit 1c, as described above, the four temporal change patterns 1 to 4 shown in FIG. 3 are stored in advance. In this embodiment, these four time course patterns, Q _k-1 is calculated from Q _k as described above, and is represented by Q _k-1 / Q k. Here, Q _k-1 is the change in luminance in the previous period _{(t k-1-N /} 2 ~t k-1 ~t k-1 + N / 2), Q k is the period after This is a change in luminance at (t _{kN / 2 to} t _{k to} t _{k + N / 2} ).

In the case of FIG. 3, the temporal change pattern 1 is “Q _k−1 / Q _k ≧ C”, the temporal change pattern 2 is “0 <Q _k−1 / Q _k <C”, and the temporal change pattern 3 is “Q _k-1 <0 and Q _k-1 / Q _k is a negative number ", and the time-varying pattern 4 is" Q _k-1 ≥0 and Q _k-1 / Q _k is a negative number " It is expressed by a condition. Here, C is a predetermined value.

As described above, the change in luminance Q _k of the lamp 4 detected by the optical sensor 17 is stored in the memory unit 1c. Projection television according to the present embodiment, the Q _k stored in the memory unit 1c, a change Q _k-1 of the luminance in the period of the previous reads Q _k of the luminance in the period after. Then, Q _k−1 , Q _k−1 / Q _k are calculated, and whether or not they match one time-varying pattern is determined as follows: time-varying pattern 1 → time-varying pattern 2 → time-varying pattern 3 → time-varying pattern 4 Judgment is made in order.

This determination is performed at predetermined time intervals in the same manner as the detection by the optical sensor 17. Incidentally, this determination, a change Q _k-1 of the luminance in the period before, after use and change Q _k of the luminance in the period. Here, the time point to be determined is a time point between the time point at which Q _k is obtained and the time point at which Q _k−1 is obtained, while the time point at which the determination is possible is obtained as Q _k. It is time. Therefore, there is a time lag between the time when the determination is made and the time when the determination is possible. However, the time lag can be reduced by shortening the interval of the time t _k when the optical sensor 17 detects the luminance and shortening the interval of the predetermined time for performing the above-described determination.

  As described above, the projection television according to the present embodiment sequentially determines whether the change in luminance of the lamp 4 detected by the optical sensor 17 matches one temporal change pattern.

  In the projection television according to the present embodiment, when it is determined that they are matched in the above-described determination, the order is advanced by one, and a predetermined correction corresponding to one matched temporal change pattern is added, and the lamp 4 Drive. In the present embodiment, the lamp 4 is driven while the drive voltage is changed by adding luminance correction factors X1 to X4 that are determined in advance corresponding to one time-varying pattern.

  Further, in the projection television according to the present embodiment, in addition to the above-described operation, the change in the brightness of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 4 that is the final temporal change pattern in the order. If determined, the remaining life of the lamp 4 is displayed. These operations will be described below with reference to FIG.

  First, as in the prior art, when the lamp 4 is turned on, the ignition voltage is supplied to the lamp 4 as the voltage 9 and then the drive voltage is supplied as the voltage 9. Then, it is determined whether the luminance change of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 1 that is the initial temporal change pattern in the order. In the present embodiment, the drive voltage is maintained at a predetermined voltage until it is determined that the change in luminance of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 1. And

FIG. 6 shows a case where it is determined that the time-dependent change pattern 1 is matched at time A after the above-described time lag elapses from time A. When it is determined in this way, the order of the temporal change pattern used for the determination is advanced by one from the temporal change pattern 1 to the temporal change pattern 2. At the same time, the lamp 4 is driven by adding a predetermined luminance correction rate X1 corresponding to the temporal change pattern 1. Aging pattern 1, to changes Q _k-1 of the luminance in the period preceding the change Q _k of luminance in the period after the gradually falls. Therefore, in this embodiment, when the luminance correction factor X1 is added, the drive voltage is changed to be increased as shown in FIG.

  Note that the drive voltage is changed so as to be within the lamp drive voltage range indicated by two one-dot chain lines in FIG. The same applies to the change of the driving voltage in the following. Thereby, an excessive voltage can be supplied to the electrode of the lamp 4 to prevent the life of the lamp 4 from becoming extremely short. The operation for realizing this will be described later.

  As described above, the order of the temporal change pattern used for determination is advanced by one from the temporal change pattern 1 to the temporal change pattern 2. Therefore, after the elapse of the above-described time lag from time A, it is determined whether or not the change in the brightness of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 2.

FIG. 6 shows a case where it is determined that the time change pattern 2 is matched at the time point B after the time lag elapses from the time point B. When it is determined in this way, the order of the temporal change pattern used for the determination is advanced by one from the temporal change pattern 2 to the temporal change pattern 3. At the same time, the lamp 4 is driven by adding a predetermined luminance correction factor X2 corresponding to the temporal change pattern 2. Aging pattern 2, with respect to the change Q _k-1 of the luminance in the period preceding the change Q _k of luminance in the period after is abruptly lowered. Therefore, in this embodiment, when the luminance correction factor X2 is added, the drive voltage is changed to be increased as shown in FIG.

  As described above, the order of the temporal change pattern used for the determination is advanced by one from the temporal change pattern 2 to the temporal change pattern 3. Therefore, after the elapse of the above-described time lag from the time point B, it is determined whether or not the luminance change of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 3.

FIG. 6 shows a case where it is determined that the time-varying pattern 3 is matched at time C after the above-described time lag elapses from time C. When it is determined in this way, the order of the temporal change pattern used for the determination is advanced by one from the temporal change pattern 3 to the temporal change pattern 4. At the same time, the lamp 4 is driven by adding a predetermined luminance correction factor X3 corresponding to the temporal change pattern 3. Aging pattern 3, with respect to the change Q _k-1 of the luminance in the period preceding the change Q _k of luminance in the period after rises rapidly. Therefore, in this embodiment, when the luminance correction factor X3 is added, the drive voltage is changed to be lowered as shown in FIG.

  As described above, the order of the temporal change pattern used for determination is advanced by one from the temporal change pattern 3 to the temporal change pattern 4. Therefore, after the time lag elapses from time C, it is determined whether or not the change in luminance of the lamp 4 detected by the optical sensor 17 matches the temporal change pattern 4.

FIG. 6 shows a case where it is determined that the time change pattern 4 is matched at the time D after the time lag has elapsed from the time D. When it is determined in this way, the lamp 4 is driven by adding a predetermined luminance correction factor X4 corresponding to the temporal change pattern 4. Aging pattern 4, to changes Q _k-1 of the luminance in the period preceding the change Q _k of luminance in the period after is abruptly lowered. Therefore, in this embodiment, when the luminance correction factor X4 is added, the drive voltage is changed to be increased as shown in FIG.

  Further, in the determination at this time, it is determined that the change in the brightness of the lamp 4 detected by the optical sensor 17 matches the time-dependent change pattern 4 that is the last time-dependent change pattern in the order. Start displaying. In the present embodiment, the control unit 2 performs control to count down from a predetermined lifetime using an internal time timer and display the value on the display unit 20 as the remaining lifetime of the lamp 4.

  7 and 8 are flowcharts showing the operation of the projection television according to the present embodiment configured as described above. Next, the operation of the projection television according to the present embodiment will be described according to these flowcharts.

  First, as an initial mode, a default aging pattern is set. In the present embodiment, the determination conditions of the four time-varying patterns 1 to 4 in FIG. 3 are stored in the memory unit 1c in the above-described order. Then, a default power supply modulation mode is set. In the present embodiment, as shown in FIG. 3, each of the luminance correction factors X1 to X4 is set for each of the four temporal change patterns 1 to 4 (step S1). The brightness correction factors X1 to X4 are changed by the user according to the type of the lamp 4 when the user replaces the lamp 4, for example.

Next, the light sensor 17 detects the luminance of the lamp 4 (step S2). After step S2, the time-averaged brightness P _n is obtained from the brightness of the lamp 4 detected by the optical sensor 17. For this P _n , Q _k is _obtained using a moving average method (step S3). Thereafter, Q _k is stored in the memory unit 1c (step S4).

After step S4, Q _k-1 and Q _k-1 / Q _k are _obtained from Q _k stored in the memory unit 1c. Then, Q _k−1 and Q _k−1 / Q _k are sequentially judged in the above-described order as to whether or not they match with the judgment condition of the temporal change pattern set in step S 1 (step S 5). If it is determined in step S5 that they do not match, the process returns to step S2. This determination is repeated every predetermined time. In this way, steps S2 to S5 are repeated until Q _k-1 and Q _k-1 / Q _k match the temporal change pattern.

  If it is determined in step S5 that they match, it is determined whether or not the matched temporal change pattern is the final temporal change pattern in the order (step S6). In the present embodiment, as described above, the time-varying pattern at the end in the order is the time-varying pattern 4.

  If it is determined in step S6 that the pattern has changed with time, the lamp burnout warning is displayed. In the present embodiment, a time timer provided inside is used to count down from a predetermined lifetime, and the value is displayed on the display unit 20 as the remaining lifetime of the lamp 4 (step S7).

  If it is determined in step S6 that it is not the final time-varying pattern, the current time-varying pattern is stored in the memory unit 1c. After being stored in the memory unit 1c, the temporal change pattern used in the determination in step S5 is shifted to the next temporal change pattern by advancing one rank from the temporal change pattern at the current stage (step S8).

  After step S8, the luminance correction rate corresponding to the current temporal change pattern is read from the memory unit 1c. Then, the drive voltage is calculated by adding the read luminance correction rate. Then, it is determined whether or not the calculated drive voltage is larger than a preset upper limit value (step S9). In the present embodiment, the upper limit value is the upper limit value of the lamp driving voltage range shown in FIG.

  If it is determined in step S9 that the calculated drive voltage is greater than the upper limit value, the drive voltage of the lamp 4 is set to the upper limit value of the lamp drive voltage range, and the drive voltage is supplied to the lamp 4 ( Step S10). Then, it returns to step S2. In this way, the drive voltage is prevented from becoming larger than the upper limit value of the lamp drive voltage range.

  When it is determined in step S9 that the calculated drive voltage is equal to or lower than the upper limit value, it is determined whether or not the drive voltage is smaller than a preset lower limit value (step S11). In the present embodiment, the lower limit value is the lower limit value of the lamp driving voltage range shown in FIG.

  When it is determined in step S11 that the calculated drive voltage is smaller than the lower limit value, the drive voltage of the lamp 4 is set to the lower limit value of the lamp drive voltage range, and the drive voltage is supplied to the lamp 4 ( Step S12). Then, it returns to step S2. In this way, the drive voltage is prevented from becoming smaller than the lower limit value of the lamp drive voltage range.

  When it is determined in step S11 that the calculated drive voltage is equal to or greater than the lower limit value, the calculated drive voltage is supplied to the lamp 4. Thereafter, the process returns to step S2 (step S13).

  According to the projection television according to the present embodiment that performs the above operation, it is sequentially determined in the above-described order whether the luminance of the lamp 4 detected by the optical sensor 17 matches a plurality of temporal change patterns. Then, the lamp 4 is driven by adding a predetermined luminance correction rate corresponding to the matched temporal change pattern. Thereby, the brightness of the image projected on the screen 8 can be prevented from becoming darker as the usage time elapses.

  In addition, according to the projection television according to the present embodiment, the remaining life of the lamp 4 is displayed when the time-varying change pattern at the end in the order is met. In this way, since the remaining life can be displayed at a time close to the life of the lamp 4, the accurate life of the lamp 4 can be displayed.

  In the present embodiment, a plurality of temporal change patterns related to the luminance of the lamp 4 are stored in the memory unit 1c in order. However, the present invention is not limited to this, and may be stored in the memory unit 3 instead of the memory unit 1c.

In the present embodiment, the plurality of temporal change patterns are stored in the memory unit 1c in order of the four temporal change patterns 1 to 4. However, the time-varying pattern is not limited to these four patterns. For example, the time-varying pattern 1 can be further timed by setting the conditions in the range of Q _k−1 / Q _k ≧ C with respect to the time-varying pattern 1. The change pattern may be increased. In this case, a plurality of temporal change patterns 1 having different determination conditions may be used without using the temporal change patterns 2 to 4.

  In the present embodiment, the case has been described in which the temporal change pattern 4 is the final temporal change pattern in the order. However, the present invention is not limited to this, and any of the temporal change patterns 1 to 3 may be a final temporal change pattern.

Further, in the present embodiment, as the change in the luminance of the lamp 4, the value Q _{k obtained} by the moving average method is used as the luminance averaged over time. However, the present invention is not limited to this, and the time-averaged luminance P _n may be used as the luminance change. However, in this case, since it is easily affected by short-term fluctuations, for example, noise, it is desirable to use the value Q _k by the moving average method.

  In the present embodiment, the brightness of the image projected on the screen 8 can be prevented from becoming darker as the usage time elapses, and the accurate remaining life of the lamp 4 can be displayed. showed that. However, the present invention is not limited to this, and only a configuration capable of displaying the accurate remaining life of the lamp 4 may be used.

  In this case, the projection television includes a lamp 4 that is a light source unit for video projection, and an optical sensor 17 that detects the luminance of the lamp 4. And the memory part 1c in which at least the last time-dependent change pattern regarding the luminance of the lamp 4 is stored is provided. When it is determined that the change in luminance of the lamp 4 detected by the optical sensor 17 matches the final time-dependent change pattern, the remaining life of the lamp 4 is displayed.

  Even with such a configuration, since the remaining life can be displayed at a time close to the life of the lamp 4 as in the above-described configuration, the accurate life of the lamp 4 can be displayed.

1 is a schematic diagram of a projection television according to Embodiment 1. FIG. FIG. 6 is a diagram illustrating an operation of the projection television according to the first embodiment. FIG. 6 is a diagram illustrating an operation of the projection television according to the first embodiment. FIG. 6 is a diagram illustrating an operation of the projection television according to the first embodiment. FIG. 6 is a diagram illustrating an operation of the projection television according to the first embodiment. FIG. 6 is a diagram illustrating an operation of the projection television according to the first embodiment. 3 is a flowchart showing an operation of the projection television according to the first embodiment. 3 is a flowchart showing an operation of the projection television according to the first embodiment. It is a schematic diagram of the conventional projection television. It is a figure which shows operation | movement of the conventional projection television.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Ballast part, 1a Lamp drive circuit, 1b Ballast control part, 1c, 3 Memory part, 2 Control part, 4 Lamp, 5 Color wheel, 6 Light pipe, 7 Projection lens, 8 Screen, 9 Voltage, 10 Lamp drive detection signal , 11 Ballast control signal, 12 Lamp drive control signal, 13 Luminance signal, 14 Color wheel control signal, 15 Color wheel operation detection signal, 16 Memory unit control signal, 17 Optical sensor, 18 DMD element, 19 DMD element control signal, 20 Display section.

Claims (2)

A light source for image projection;
An optical sensor for detecting the luminance of the light source unit;
And regarding the luminance of the light source unit, associated with the passage of use time, and a memory unit for aging pattern is stored in the plurality of luminance associated hierarchy to end from the beginning,
When it is determined that the change of the luminance of the light source unit detected by the optical sensor at a predetermined time interval matches one of the luminance temporal change patterns in order, and it is determined that they match. , together with the use of the following one aging pattern on the order of the one aging pattern matching from the next determination, the addition of predetermined correction corresponding to a change over time pattern the coincides Driving the light source unit while changing the driving voltage of the light source unit;
Projection television. When it is determined that the change in luminance of the light source unit detected by the light sensor matches the temporal change pattern at the end of the order, the remaining life of the light source unit is displayed.
The projection television set according to claim 1.

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