JP4534647B2 - Projection display device and multi-screen system - Google Patents

Description

  The present invention relates to a projection display apparatus that forms an optical image by modulating light intensity of light from a light source using a display panel such as a liquid crystal panel and projects the optical image on a screen. In particular, the present invention relates to a projection display apparatus in which there are a plurality of light sources, and these are switched to light.

  In a projection display apparatus that modulates light intensity of light from a light source using a display panel, forms an optical image corresponding to a video signal, and projects it, a light source such as a discharge lamp (hereinafter simply referred to as “high pressure mercury lamp”). Abbreviated as “lamp”). This lamp has a short life compared to that of a cathode ray tube. Therefore, for example, as disclosed in Patent Document 1 or 2, the sensor or the light source power source detects that the currently used light source is cut off and is not lit, as disclosed in Patent Document 1 or 2. It has been proposed to extend the service life by automatically switching to the other light source.

  There are various methods other than the above as the light source switching method. For example, in Patent Document 3, it is proposed to set a lighting time in which the light amount of a light source is expected to start decreasing in advance and switch from the currently used light source to the other light source when the lighting time is reached. ing.

  Further, Patent Document 4 proposes that a plurality of light sources be switched and operated at predetermined time intervals to average the light source usage time.

JP-A-7-225430 JP 7-225431 A Japanese Patent Laid-Open No. 11-149061 JP 2001-357984 A

  In the above-described projection display devices of Patent Documents 1, 2, and 3, switching to another light source is performed by detecting the non-lighting or measuring the lifetime prediction time, and the lighting time is extended by the number of light sources. For example, if two light sources are used, it is possible to view without interruption for twice as much time as in the case of one light source. However, these disclosed technologies are aimed at interrupting viewing or reducing the replacement frequency of the light source lamp, and do not extend the life of the lamp itself.

  For example, a projection display device that is used in the field of monitoring and control and that requires continuous operation for 24 hours and 365 days is required to be able to watch without being interrupted for a long period of time. Therefore, a plurality of light sources are used to satisfy this requirement. However, in order to achieve stable viewing over a longer period, it is desired to extend the life of the lamp itself.

  In addition, in the projection display device that alternately switches a plurality of light sources at a preset time disclosed in Patent Document 4, for example, when two light sources are used, one cumulative lighting time becomes longer than the other, However, control is performed for the purpose of aligning (averaging) the cumulative lighting time of a plurality of light sources so that the lamp does not burn out earlier (does not turn off), and does not extend the life of the lamp itself. Furthermore, according to the disclosed technology, since the cumulative lighting time of a plurality of light sources is averaged, all the light sources reach the end of life almost at the same time, and even though there are a plurality of light sources, a complete non-lighting state There is a risk of falling into.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a projection display device capable of extending the life of a light source without averaging the cumulative lighting time of a plurality of light sources, and The object is to provide a multi-screen system used in combination.

  In order to achieve the above object, a projection display apparatus according to the present invention selectively turns on one of a first light source and a second light source (that is, turns on the first and second light sources alternately). The control means for controlling the first and second light sources is provided so that the lighting time of the first light source and the lighting time of the second light source are different from each other. Here, when paying attention to the first light source, the first light source repeats a lighting state and a light-off state at a predetermined cycle (for example, 12 hours and 24 hours), but the lighting time is set to be longer than the light-off time. Control. When the first light source is turned off, the second light source is turned on.

  The light source switching control is performed in accordance with a first set time that determines the lighting time of the first light source and a second set time that determines the lighting time of the second light source and is shorter than the first set time. . At this time, the first or second set time may be a time that is 2/100 or less of the lifetime of the light source (the lifetime when the first or second light source is continuously turned on). The lower limit of the first or second set time may be approximately 4 hours.

  In the multi-screen system according to the present invention, a plurality of projection display devices including the control means are combined, and the switching control by the control means is not performed simultaneously between the plurality of projection display devices. It is characterized by that.

  Thus, in the present invention, when attention is paid to one of the first and second light sources, the length of the light source can be increased by turning on the light source only during a unit lighting time set within a predetermined period. This is intended to extend the service life. That is, the present invention has been made on the basis of a new finding obtained by experiments and examinations by the present inventors that the light source can have a longer life than the continuous lighting when the intermittent lighting is used. Then, the present invention makes the cumulative lighting times of the first and second light sources different by making the lighting times in these predetermined cycles different from each other while the first and second light sources are intermittently lit at a predetermined cycle. This makes it possible to extend the service life.

  According to the present invention, it is possible to extend the lifetime of a plurality of light sources as compared to the lifetime during continuous lighting without averaging the cumulative lighting time of each light source.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the invention will be described in detail with reference to the drawings. Before that, the basic principle of the present invention will be described.

As a result of examining the extension of the light source life in a projection display device using a plurality of light sources, the present inventors have found the following novel findings. That is, the first predetermined time (T _on time) is turned on and the second predetermined time (T _off time) is _rested from the continuous lighting life time when measured by continuously lighting until the lamp is turned off (no lighting). This is a finding that the intermittent lighting life time becomes longer when measured until the lamp is turned off (not lighted) in units of cycles (of course, the rest period is not included in the life time). Furthermore, in the case of intermittent lighting in which such a pause period is provided to intermittently light, it has been found that the shorter the lighting period (T _on time), the longer the lifetime.

  FIG. 1 schematically shows the life characteristics of a 100 W high pressure mercury lamp. In FIG. 1, 101 is a life characteristic at the time of continuous lighting, 102 is a lighting period of 167 hours (hereinafter, 1 hour is represented by “h”), and a rest period of 1 h. Characteristic 103 is a life characteristic during intermittent lighting with a lighting period 11h and a rest period 1h. The horizontal axis in FIG. 1 is the cumulative lighting time, and the vertical axis is the remaining rate of the lamp as the light source. As is apparent from FIG. 1, the intermittent lighting life characteristic 102 has a cumulative lighting time of 50% remaining rate (hereinafter simply referred to as “cumulative lighting time”) more than double the cumulative lighting time of the continuous lighting life characteristic 101. In addition, the intermittent lighting life characteristic 103 further extends the cumulative lighting time as compared with that of the intermittent lighting life characteristic 102. That is, as the lighting period of one cycle period (hereinafter, this lighting period is referred to as “unit lighting period”, and the time length of this period is referred to as “unit lighting period”), the life characteristic is extended (lengthened). I understand that. In general, the average life (50% survival rate) of a 100 W high-pressure mercury lamp is about 8000 hours, and the unit lighting period of the intermittent lighting life characteristic 102 is about 2% of the continuous lighting life. The unit lighting period is about 0.14% of the continuous lighting life.

  In the projection display device using a plurality of light sources, the present invention makes use of the life characteristic that the life of the lamp is extended if driven intermittently. For example, when two light sources are used, the two light sources are turned on alternately. (It turns on intermittently when focusing on one light source), and the length of the unit lighting period (unit lighting time) is varied, and the longest unit lighting period is about two-hundreds of the lifetime of continuous lighting. It is characterized by the following times. The length of the unit lighting period (unit lighting time) is made different in order to avoid the interruption of viewing by extending the lamp life time so as not to reach the lamp life almost at the same time.

  The present invention is effective for a projection display device that is continuously operated over a long period of time, and is suitable for a display device for monitoring and controlling, for example, electricity, gas, and water.

  FIG. 2 is a schematic configuration diagram of the projection display apparatus according to the first embodiment of the present invention. Hereinafter, in order to simplify the description, it is assumed that there are two light sources, but the present invention is not limited to this, and there may be two or more.

  In FIG. 2, the projection display device has a first light source 1A and a second light source 1B. A light beam from either one of the light sources is modulated by the optical unit 5 to form an optical image. The image is enlarged and projected onto the screen 9. As an example of the optical unit 5, an illumination optical system (not shown), a color separation means (not shown) that separates a white light beam from a light source irradiated by the illumination optical system into three primary colors of light, and a color separation means Liquid crystal panels 6A, 6B, and 6C that form optical images via the liquid crystal drive circuit 21 by performing light intensity modulation that changes the separated color lights (not shown) into light shades according to the video signal Sv; A cross prism 7 for synthesizing optical images of the respective color lights formed by the liquid crystal panel 6 and a projection lens 8 for enlarging and projecting the color optical image synthesized by the cross prism 7 are provided.

  Reference numeral 2A (2B) includes a light source lighting detection means 2Aa (2Bb) for driving the first light source 1A (second light source 1B) and detecting that the first light source 1A (second light source 1B) is lit. A driving power source, 4 is a motor, and 3 is a movable mirror disposed on the rotating shaft of the motor 4. 10 performs lighting control so that the first light source 1A and the second light source 1B are alternately turned on via the driving power supplies 2A and 2B, and is turned on in synchronization with the lighting of the first light source 1A or the second light source 1B. This is a control circuit that controls the angle of the reflecting mirror surface of the movable mirror 3 by driving the motor 4 so that the light beam from the light source enters the optical unit 5. The control circuit 10 includes means such as an accurate positioning of the movable mirror 3, a stopper for restricting excessive movement of the motor, and a limiter. Further, the control circuit 10 receives a remote control signal from the optical remote controller 14 for remote operation of the projection display device received by the remote control light receiving unit 30. 11 is a timer for measuring the lighting time of the first light source 1A and the second light source 1B, 12 is a unit lighting time of each light source 1A (1B), lighting period information of each light source indicating which light source is in the lighting period, A memory 13 for storing non-lighting information (lamp light information) indicating non-lighting (lamp-off) of each light source, and a CPU 13 for performing control for operating the entire projection display device. The CPU 13 controls the entire projection display device in accordance with a program stored in a ROM (not shown), and unit lighting time, lighting period information (flag), non-lighting information (flag) of each light source stored in the memory 12. In addition, using the measurement information from the timer 11 based on the unit lighting time of the light source set in the timer 11, the first light source 1A and the second light source 1B are controlled to be alternately turned on via the control circuit 10. Further, if necessary, the CPU 13 has a function of superimposing predetermined display information in the memory 12 on the video signal Sv by the OSD circuit 22 and displaying it on the screen via the liquid crystal driving circuit 21.

  In the memory 12, the unit lighting time of each light source is set in advance by the user using the optical remote controller 14 or input means (not shown). This unit lighting time differs for each light source. For example, the unit lighting time of the first light source 1A is set to 11h, and the unit lighting time of the second light source 1B is set to 1h. Hereinafter, for convenience, the first light source may be referred to as a main light source and the second light source as a secondary light source.

  The first light source 1A, the second light source 1B, the movable mirror 3, and the motor 4 constitute a light source unit, and the control circuit 10, the timer 11, the memory 12, and the CPU 13 constitute a control unit.

  In the projection display device configured as described above, the first light source 1 </ b> A and the second light source 1 </ b> B are controlled by the CPU 13 so as to be alternately lit at the unit lighting time set for each light source. That is, the CPU 13 refers to the unit lighting time of each light source set in the memory 12 to instruct the timer 11 to measure time, and the first light source 1A and the second light source 1B are alternately switched according to the time measurement result of the timer 11. The control circuit 10 is instructed to illuminate, and the control circuit 10 receives the instruction and switches the lighting of the first light source 1A and the second light source 1B alternately via the drive power supplies 2A and 2B. The light beams from the first light source 1A and the second light source 1B are incident on the optical unit 5 as the movable mirror 3 is rotated by the control circuit 10 which is formed in synchronization with the lighting of the first light source 1A and the second light source 1B. The color optical image formed by the optical unit 5 is enlarged and projected on the screen 9.

  Next, with reference to the flowcharts of FIGS. 3, 4, and 5, the alternate driving process of a plurality of light sources in the projection display device will be described in detail. Here, for ease of explanation, description will be made based on the projection display device shown in FIG. 2, and the unit lighting time of the first light source 1A is 11h and the unit lighting time of the second light source 1B is 1h. And

  FIG. 3 is a flowchart of unit lighting time setting processing in a projection display device having two light sources. FIG. 4 is a flowchart of light source switching processing in a projection display apparatus having two light sources. FIG. 5 is a detailed flowchart of the light source switching process from the first light source to the second light source in FIG.

  First, the flowchart of FIG. 3 will be described. In FIG. 3, in the unit lighting time setting process for setting the unit lighting time, for example, when the user presses a unit lighting time setting key (not shown) of the optical remote controller 14, the CPU 13 starts the unit lighting time setting process. . The unit lighting time setting key (not shown) is a key for instructing on / off of the unit lighting time setting process, and the unit lighting time setting mode is entered by the first operation. ) Is cleared when operated.

  When the unit lighting time setting process is started, first, the unit lighting time setting mode of the first light source 1A is set. When a desired unit lighting time, for example, 11h is set with a numeric key (not shown) and a decision key (not shown) of the optical remote controller 14 at step 111 (hereinafter, step is abbreviated as “S”), The CPU 13 stores the set unit lighting time of the first light source in the memory 12. Next, when the unit lighting time setting mode of the second light source 1B is set and a desired unit lighting time, for example, 1h is set in S112, the CPU 13 stores the set unit lighting time of the second light source in the memory 12. Then, the unit lighting time setting process ends.

  In the above description, the unit lighting time is input by the user. For example, when setting the unit lighting time, the combination candidate display of the unit lighting times of the first light source and the second light source is superimposed on the video signal Sv by the OSD circuit 22. At the same time, it may be displayed on the screen via the liquid crystal driving circuit 21 and selected from several candidates using the direction key (not shown) and the enter key (not shown) of the optical remote controller 14.

  Next, the flowchart of the light source switching process of FIG. 4 will be described. Here, for convenience, the description will be made assuming that one of the two light sources is being lit. In FIG. 4, when the light source switching process is started, the CPU 13 first reads out the non-lighting information (flag) of the first light source stored in the memory 12 in S121, and checks whether the first light source is out of lamp. If it is determined that the lamp cannot be used due to the lamp being out, a first light source lamp replacement instruction display is displayed on the screen via the liquid crystal driving circuit 21 in S122, and the process goes to S131. If it can be used, the process goes to S123, and the lighting period information (flag) of the first light source stored in the memory 12 is read and checked to determine whether it is the lighting period of the first light source. If it is not the lighting period, the process goes to S131. If it is the lighting period, the process goes to S124, and the light source lighting detection means 2Aa in the driving power source 2A of the first light source detects whether the lamp of the light source 1A is burned out. If the lighting is performed without any abnormality in S124, the process goes to S127, and it is determined by checking the time measurement value of the timer 11 whether or not the set unit lighting time of the first light source has been exceeded. The timer 11 is set with a unit lighting time in the memory 12 when the light source is turned on, and the timer 11 counts down from this value. Therefore, if the count value becomes 0, it is known that the unit lighting time has elapsed. Can do. If the first light source is not turned on in S124, the non-lighting information (flag) of the first light source is set in the memory 12 in S125, the first light source lamp replacement instruction is displayed in S126, and the process goes to S131. If the set unit lighting time has elapsed in S127, the first light source → second light source switching process in S150 is executed, the light source switching process is terminated, and the process returns to the main process. If it has not elapsed, the light source switching process is terminated and the process returns to the main process.

  S131 to S137 and S160 are processes relating to the second light source, corresponding to the above-described processes relating to the first light source of S121 to S127 and S150, and the operation is the same, and the description thereof is omitted.

  The light source switching process described above is incorporated in the main process flow, and the above process is repeated every predetermined time.

  Next, details of the first light source → second light source switching process of S150 described in FIG. 4 will be described with reference to the flowchart of FIG. In FIG. 5, when the first light source → second light source switching process is started, the CPU 13 instructs the drive power source 2B to turn on the second light source 1B via the control circuit 10 in S151, and the second light source 1B in S152. Is turned on by the detection result of the light source lighting detection means 2Bb built in the drive power supply 2B via the control circuit 10. If it is determined not to be lit in S152, a flag of non-lighting information is set in the memory 12 in S153, a lamp replacement instruction is displayed in S154, and a lighting continuation process is performed so that the first light source is continuously lit in S155. To exit.

  When it is determined in S152 that the second light source 1B is normally lit, the process goes to S156 and waits for a predetermined time until the second light source 1B exhibits a sufficient amount of light. When the light quantity is stabilized, in S157, the CPU 13 rotates the motor 4 via the control circuit 10 in a time of 1 second or less, and the movable mirror 3 reflects the light from the second light source 1B to the optical unit 5. In step S158, the unit 11 is set to the unit lighting time of the second light source, and time measurement is started. In step S159, the first light source 1A is turned off, and the light source switching process ends.

  Note that the second light source → first light source switching process in S160 is the same as the light source switching process in S150, and the description of the operation is omitted.

  Since the light source switching process is configured as described above, even if the first light source and the second light source are both normally lit even in the continuous operation state of 24 hours 365 days, for each set unit lighting time. In other words, if the set unit lighting time is 11h and 1h, for example, the first light source is turned on for 11h and the second light source is turned on for 1h (period of 12 hours). As shown in the life characteristics 102 and 103 of FIG. 1, for example, the life of the lamp of the light source itself can be extended. In addition, the unit lighting time of each light source is made different so that the cumulative lighting time is not averaged, so that the risk of the lamp reaching the end of its life can be reduced almost at the same time, and the interruption of hearing due to the lamp burnout is avoided. Can do. In addition, according to the present embodiment, when it is detected that the light source that has been turned on is not turned on, the light source is automatically switched to another light source, and it is avoided that the screen becomes dark and the hearing is interrupted. The lamp replacement (replacement of a non-lighted lamp with a new lamp) is displayed to prompt the user to replace the lamp, so that all of the lamps of the plurality of light sources can be prevented from being turned off.

  In the above description, the unit lighting time of the first light source, which is the main light source, is 11 h, and the cycle is 12 hours, with the unit lighting time of the second light source being 1 h. However, the present invention is not limited to this. As the unit lighting time of the main light source, it is desirable to set the time within about two hundredths of the life time during continuous lighting from the intermittent lighting life characteristics of FIG. Further, if the light source is switched frequently, the luminance fluctuation at the time of the light source switching may be annoying to the viewer. Therefore, the unit lighting time of the main light source is preferably several hours or more, for example, 4 hours or more. The cycle may be a 24-hour cycle in which the unit lighting time of the first light source is 23 h and the unit lighting time of the second light source is 1 h, or a 6-hour cycle, an 8-hour cycle, and 168 hours. It is also possible to set any time, such as a cycle (weekly cycle).

  In the above description, the unit lighting time of each light source is input using the optical remote controller 14. However, the present invention is not limited to this. For example, external control is performed using a communication line (not shown). You may make it input from a terminal (not shown).

  In the above description, the case where the image is continuously displayed for a long time (for example, 24 hours or more) has been described. However, in a time shorter than the unit lighting time of the main light source, for example, with the power key (not shown) of the optical remote controller 14, In the case of the pseudo power-off state, the CPU 13 resets the timer 11 that measures the unit lighting time (for example, sets the measuring time to zero), and at the next power-on, the timer 11 again sets the unit lighting time of the main light source. By setting it to be measured, it is possible to provide a projection display device that does not perform unnecessary alternating operation.

  Also, the alternate lighting mode (continuous operation mode) is set by, for example, an alternate lighting setting key (not shown) of the optical remote controller 14 so that the alternate lighting mode (continuous operation mode) is turned on / off. In this case, or when the alternate lighting mode is set on the menu screen on which the alternate lighting mode is displayed, the alternate lighting operation described above may be performed. Otherwise, the alternate lighting operation may not be performed.

  FIG. 6 is a schematic configuration diagram of a projection display apparatus according to the second embodiment. In the first embodiment, for example, the alternate lighting (intermittent lighting) is performed at a cycle of 12 hours. However, in this embodiment, a clock for measuring time is provided instead of the timer, and the alternate lighting is controlled at the lighting start time. To. Accordingly, FIG. 6 includes a clock 15 that records the current time. The CPU 13 ′ is different from the CPU 13 of the first embodiment in that the alternate lighting is controlled by the lighting start time, and the others are the same. In the present embodiment, similarly to the first embodiment, it is assumed that two light sources are provided. Needless to say, the present invention can be applied to two or more light sources.

  In this embodiment, in order to switch the light source at a predetermined time, the lighting start time of the unit lighting period of the first light source (that is, the second light source → first light source switching time) and the lighting start of the unit lighting period of the second light source. The time (that is, the first light source → second light source switching time) is set by, for example, the optical remote controller 14 serving as input means. Accordingly, the CPU 13 periodically watches the current time of the clock 15, and turns on the first light source and the second light source when it coincides with the lighting start time of the first light source stored in the memory 12. When the second light source is turned on, the operation of turning on the second light source and turning off the first light source is repeated.

  Now, as a display device used as a monitoring device that is operated continuously for 24 hours 365 days, for example, the lighting start time of the first light source and the lighting start time of the second light source are not very busy. (For example, at midnight and 11:00 p.m. in the middle of the night), there is no possibility of causing trouble even if there is some luminance fluctuation due to light source switching.

  With this setting, it is possible to repeat an intermittent lighting cycle in which the main first light source is turned on at midnight and the second light source is turned on in accordance with 23:00 (11:00 pm). The same effect as that of the first embodiment, that is, the lifetime of the lamp of the light source itself can be extended. In addition, the unit lighting time of each light source is made different so that the cumulative lighting time is not averaged, so that the risk of the lamp reaching the end of its life can be reduced almost at the same time, and the interruption of hearing due to the lamp burnout is avoided. Can do.

  In the above description, the light source lighting is controlled using a clock. However, the present time is not limited to the clock, and the current time information is managed by the Japan Standard Time Group of the National Institute of Information and Communications Technology. It may be obtained through the “standard radio wave” or the Internet / telephone line.

  In addition, by providing a clock, it is possible to register a schedule in advance such as every day and night, every day of the week, every week, every month, etc. It becomes easy to execute.

  For example, when using a projection display device as a monitoring device, there are many busy hours in the daytime, so the frequency of light source switching is reduced, and the frequency of light source switching is increased at less busy nights. Even if there are some luminance fluctuations due to light source switching, the trouble can be minimized. Similarly, since Sunday is not as busy as weekdays, the frequency of light source switching on weekdays can be reduced and the frequency of light source switching on Sundays can be increased to minimize the impact of light source switching. it can.

  In addition, when changing the frequency of the said light source switching frequency in a time slot | zone as mentioned above, you may make it change the switching frequency by changing the unit lighting time of the main light source.

FIG. 7 is an example of a multi-screen system showing a third embodiment in which the projection display apparatus of the second embodiment described in FIG. 6 is combined with four vertical rows and four horizontal rows. In the multi-screen system of FIG. 7, the projection display device 19 is referred to as a cube display device. Each of the projection display devices 19 is established as an independent display device, and can be used in combination. Each projection display device 19 includes 19 ₁ , 19 ₂ ,..., 19 _i (hereinafter, any projection display device is denoted by reference numeral 19 _i ),..., 19 ₁₅ , 19 ₁₆ from the upper left corner of FIG. It is arranged in four vertical rows and four horizontal rows, and has a display unit 20 comprising a light source unit, a control unit, an optical unit, a liquid crystal drive circuit, a screen, etc. as shown in FIG. When doing so, the communication terminal 17 is connected to the control terminal 18.

The control terminal 18 is set in advance with a lighting start time of a unit lighting period, which is light source switching information in each projection display device 19 _i . This setting content is the same as the setting in the projection display apparatus of the second embodiment described above, for example, as the length of the unit lighting period, that is, the unit lighting time, approximately 100% of the light source lifetime during continuous lighting. In the case where there are two light sources, the lighting time of the main light source and the sub light source is made to be long or short, the light source switching cycle is set to 12 hours, or the 24-hour cycle is set. Needless to say, the device such as the above can also be applied to a multi-screen system.

  In addition, if light source switching is performed all at once, brightness fluctuations are conspicuous on the entire screen, and viewing may become difficult, so the lighting start times in each projection display device are set different from each other by a predetermined time. The light source is not switched at a time.

The light source switching information of each projection display device 19 _i set in the control terminal 18 is transmitted to each corresponding projection display device 19 _i via the communication line 17 every predetermined time as necessary. These are stored in the memory 12 of each projection display device 19 _i .

Each projection display device 19 _i which is constructed as described above, at the light source switching time (lighting start time of the unit lighting period), for example, at the light source switching time of the projection display device 19 _1, the projection display device 19 ₁ performs predetermined light source switching process, then shifted by a predetermined time to become a source switching time of the projection display device 19 _2, the projection display apparatus 19 ₂ performs a predetermined light source switching process. Thus, the light source switching process of each projection display device 19 _i is executed one after another at predetermined time intervals. In this way, even if brightness fluctuation occurs due to light source switching, the fluctuation occurs with a time lag for each projection display device, so that it can be made inconspicuous. Further, at the time of switching the light source, as described in FIG. 5, both the first light source and the second light source are turned on for a while, so that the light source driving current increases. However, the light source switching is performed all at once as in this embodiment. Without switching, the projection display devices are switched with a time shift, so that it is possible to avoid a rapid increase in the light source driving current in the entire multi-screen.

  In the present embodiment described above, light source switching information is sent from the control terminal 18 to each projection display device, and based on this, each projection display device performs light source switching of a plurality of light sources. For example, the control terminal 18 may exchange commands with the CPU of each projection display device via the communication line 17 to directly control light source switching.

A diagram schematically showing the life characteristics of a 100W high-pressure mercury lamp. 1 is a schematic configuration diagram of a projection display apparatus according to a first embodiment. Unit lighting time setting process flow chart Flow diagram of light source switching process Detailed flow chart of light source switching process Schematic configuration diagram of a projection display device showing a second embodiment Diagram showing an example of a multi-screen system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A ... 1st light source, 1B ... 2nd light source, 2A ... Drive power supply, 2Aa ... Light source lighting detection means, 2B ... Drive power supply, 2Bb ... Light source lighting detection means, 3 ... Movable mirror, 4 ... Motor, 5 ... Optical unit, 6A, 6B, 6C ... Liquid crystal panel, 7 ... Cross prism, 8 ... Projection lens, 9 ... Screen, 10 ... Control circuit, 11 ... Timer, 12 ... Memory, 13 ... CPU, 14 ... Optical remote control, 15 ... Clock, 16 DESCRIPTION OF SYMBOLS ... Multi-screen system, 17 ... Communication line, 18 ... Control terminal, 19 ... Projection type display apparatus, 20 ... Display unit, 21 ... Liquid crystal drive circuit, 22 ... OSD circuit, 30 ... Remote control light-receiving part, 101 ... Continuous lighting Life characteristics, 102, 103 ... Life characteristics when intermittent lighting is performed.

Claims (12)

In a projection display device,
A first light source; a second light source; a display panel that modulates light from the first or second light source; projection means that projects the light modulated by the display panel on a screen; and the first or second light source. Control means for selectively lighting any one of these as a light source for irradiating the display panel with light,
The control means includes a first set time for determining a lighting time of the first light source , which is 2/100 or less of a lifetime during continuous lighting of the first and second light sources, and the second light source. The projection display apparatus is characterized in that switching control is performed so that the first and second light sources are alternately lit according to a second set time shorter than the first set time.   2. The projection display device according to claim 1, further comprising optical switching means for irradiating the display panel by switching light from the first light source and light from the second light source. A projection display apparatus that controls the optical switching means in synchronization with the switching control to the first and second light sources.   The projection display apparatus according to claim 1, wherein the total of the first set time and the second set time is 12 hours.   2. The projection display device according to claim 1, wherein a total of the first predetermined time and the second predetermined time is 24 hours.   2. The projection display device according to claim 1, further comprising a timer for measuring a lighting time of the first light source or the second light source, wherein the control means measures the lighting time of the first light source measured by the timer. When the first set time is exceeded, switching control from the first light source to the second light source is performed, and when the lighting time of the second light source measured by the timer exceeds the second set time, the second light source A projection display device that performs switching control to a first light source.   2. The projection display device according to claim 1, further comprising light source lighting detection means for detecting lighting of the first or second light source, wherein the control means is operated by the light source lighting detection means during the first set time. When the lighting of the first light source is not detected, switching control from the first light source to the second light source is performed, and the lighting of the second light source is not detected by the light source lighting detection means during the second setting time. A projection display device that performs switching control from the second light source to the first light source in the event of a failure.   2. The projection display device according to claim 1, further comprising a clock function capable of setting a time for executing the switching control of the first and second light sources, wherein the control means is configured to perform the control according to a time set for the clock function. A projection display device characterized by executing switching control.   8. The projection display apparatus according to claim 7, wherein the set time is set for each daytime and nighttime period.   8. The projection display apparatus according to claim 7, wherein the set time can be set for each day of the week, for each week, for each month. A first light source; a second light source; a display panel that modulates light from the first or second light source; projection means that projects the light modulated by the display panel on a screen; and the first or second light source. In a multi-screen system that uses a combination of a plurality of projection display devices including control means for controlling to selectively light one of
The lighting time of the first light source and the lighting time of the second light source are times less than 2/100 of the lifetime during continuous lighting of the first and second light sources, and the control means Switching control of the first and second light sources so that the lighting time of the light source and the lighting time of the second light source are different from each other;
The multi-screen system, wherein the switching control by the control means is not performed simultaneously between the plurality of projection display devices. In a projection display device,
A first light source; a second light source; a display panel that modulates light from the first or second light source; projection means that projects the light modulated by the display panel on a screen; and the first or second light source. And control means for controlling to selectively light one of the
The control means controls one of the first light source and the second light source to switch to the other light source after lighting for a predetermined time, and sets the predetermined time for determining the lighting time of the light source to the first light source. Alternatively, the projection type display apparatus is characterized in that the lifetime of the second light source is set to 2/100 or less and the lighting time of the first light source is different from the lighting time of the second light source .   12. The projection display device according to claim 11, wherein a lower limit of the predetermined time is approximately 4 hours.

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