JP5503374B2 - Image projection device - Google Patents

Description

  The present invention relates to an image projection apparatus (projector) that projects an image formed on an image display element (liquid crystal panel, light guide, etc.) on an irradiated surface by a projection optical system.

  Conventionally, various image projection apparatuses (liquid crystal projectors) for enlarging and projecting an image based on an image display element (liquid crystal panel, light valve) on a screen by a projection optical system have been proposed as apparatuses for observing an enlarged projection image. Yes. In the field of image projection devices, in the field of always-installation type such as presentations and exhibitions, there are demands such as high brightness of projected images and long life of light source means.

  In order to satisfy these requirements, a plurality of light sources (lamps) are provided, and switching control of a plurality of light sources that are turned on according to the projection mode is performed. For example, when importance is attached to the brightness of the projected image, a plurality of lights are turned on simultaneously. Further, when importance is attached to the life of the light source, lighting control such as lighting only one lamp is performed. At that time, as a control method for making the life of the light source as long as possible, there is known an image projection apparatus that uses a method for managing lighting times of a plurality of lamps and controlling lighting with priority from a lamp with a short lighting time. (Patent Document 1).

JP 09-096786 A

  In general, the lighting time and life of a light source are not always in a proportional relationship. For example, when there is a lamp A with the cumulative lighting time ta and a lamp B with the cumulative lighting time tb (provided that ta> tb), the lamp A always has a larger light quantity attenuation rate than the lamp B, and the life is shortened. Not exclusively. In many cases, the light amount attenuation rate, that is, the lifetime is caused by variations inherent in the lamp.

  Therefore, even if the lifetime is simply estimated based on the cumulative lighting time of the light source, a complete system for extending the lifetime of the light source cannot be obtained. In addition, for example, when using a video mode (cinema mode) suitable for movie viewing, color tone or the like may be more important than the brightness of the projected image. In this case, although a long-life lamp, that is, a bright lamp is used, there is a problem in that the amount of projection light is reduced by attenuating the signal level by gamma conversion or gain processing.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image projection apparatus that can easily achieve a long life of a light source.

An image projection apparatus according to the present invention is an image projection apparatus that projects an image illuminated with a light beam when one or a plurality of light sources among a plurality of light sources is turned on, and a light source that drives each of the plurality of light sources. The light source lighting control means includes a light source light quantity measuring means for measuring the light quantity emitted from the plurality of light sources, a storage means for storing a measurement history of the light source light quantity measuring means, and the light source. A light source light quantity managing means for managing the plurality of light sources by obtaining a light quantity attenuation rate of each light source from the light quantities emitted from the plurality of light sources measured by the light quantity measuring means, and turning on the light source control means, when turning it selects some of the plurality of light sources, that preferentially lighting control than other light sources small source of light intensity attenuation rate of the light source which has been determined by the amount of source light management unit It is a symptom.

  According to the present invention, an image projection apparatus with a long light source life can be obtained.

It is the figure which showed the structure of the image projection apparatus of Example 1 of this invention. It is the figure which showed the structure of the lamp lighting control means contained in Example 1. FIG. It is the figure which showed an example of the lamp life estimation method. 3 is a flowchart illustrating a processing flow of the first embodiment. 3 is a flowchart illustrating a processing flow of the first embodiment. It is a figure of the light quantity change which showed the effect of this invention. It is the figure which showed the structure of the image projection apparatus of Example 2 of this invention. It is the figure which showed the structure of the lamp lighting control means contained in Example 2. FIG. 10 is a flowchart illustrating a processing flow of the second embodiment. 10 is a flowchart illustrating a processing flow of the second embodiment.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The image projection apparatus of the present invention projects a light illuminated with a light beam when a plurality of light sources (lamps) 14 and 17 and one or more of the light sources 14 and 17 are turned on. Projecting on the screen. Here, the number of light sources may be two or more and any number. A plurality of light source driving means (lamp driving means) 13 and 16 for driving a plurality of light sources, respectively, and a light source lighting control means (lamp lighting control means) 19 for independently controlling the plurality of light source driving means 13 and 16 are provided. Furthermore, it has light source light quantity measuring means (optical sensors) 15 and 18 for measuring the light quantity emitted from a plurality of light sources. Here, the aforementioned light source lighting control means may include a plurality of light source driving means, and the plurality of light source driving means may be included in the light source.

  The light source lighting control unit 19 includes a light source light amount management unit 20 that performs history management of light amounts emitted from a plurality of light sources using signals from the light source light amount measurement units 15 and 18. Furthermore, the light source lighting control unit 19 selectively drives one or a plurality of (a part of the light source driving units) among the plurality of light source driving units 13 and 16 based on the information from the light source light quantity management unit 20. Light source selection lighting control means 21 is provided. The light source light quantity management means 20 manages the plurality of light sources by obtaining the light quantity attenuation amount of each light source from the light quantities emitted from the plurality of light sources 14 and 17 measured by the light source light quantity measurement means (optical sensors) 15 and 18. ing. For example, it manages which light source should be turned on among a plurality of light sources. The light source selective lighting control unit 21 controls lighting of a light source having a small light amount attenuation rate obtained by the light source light amount management unit 20 with priority over other light sources. Here, the light source lighting control unit 21 may include both the light source selection lighting control unit 21 and the light source light amount management unit 20 based on the output from the light source light amount management unit 20.

  In addition, the image projection apparatus of the present invention may have a projection mode setting means 30 for setting or selecting a projection mode when projecting an image. At this time, the light source selective lighting control unit 31 selectively drives one or a plurality of the plurality of light source driving units 13 and 16 based on information from the light source light amount management unit 20 and the projection mode setting unit 30. ing. The light source light quantity management means 20 further manages the plurality of light sources 14 and 17 by obtaining the absolute light quantity of each light source from the light quantities emitted from the plurality of light sources 14 and 17.

  Here, in the projection mode setting means 30, priority is given to the life priority mode for the purpose of maintaining the brightness by the light flux emitted from the light source for a long period of time and other items than to maintain the brightness for a long period of time. Including brightness non-priority mode. The light source selection lighting control unit 31 lights a light source having a small light amount attenuation rate of the light source obtained by the light source light amount management unit 20 with priority over other light sources when the projection mode setting unit 30 selects the life priority mode. Control is in progress. When the brightness non-priority mode is selected by the projection mode setting means 30, the light source having the smaller absolute light quantity obtained by the light source light quantity management means 20 is controlled to be turned on preferentially.

[Example 1]
FIG. 1 is a principal block diagram of a configuration of a projector (image projection apparatus) in Embodiment 1 of the present invention. First, a signal flow until a projection image is displayed on the display panel (image display element) 12 will be briefly described.

  The video signal processing unit 10 performs video signal processing such as color processing such as gamma conversion and color conversion processing, and luminance processing on the video input signal Video_In. Generally, each of these processes is selected in conjunction with the video mode setting performed by the user. For example, when the user sets “presentation mode”, gamma correction processing and color conversion processing for the presentation mode are performed. When “cinema mode” is set, gamma correction processing for the cinema mode is performed. Color conversion processing and the like are performed. The video signal that has been subjected to various types of video signal processing in the video signal processing unit 1 is subjected to conversion suitable for driving the display panel 12 by the panel drive circuit 11, and an image is displayed on the display panel 12.

  Next, control of a light source (lamp) for projecting an image on the display panel 12 will be described. In this embodiment, a system including two lamps is taken as an example. There may be two or more lamps. A lamp A driving circuit (light source driving means) 13 and a lamp B driving circuit (light source driving means) 16 are connected to the lamp A (light source) 14 and the lamp B (light source) 17 respectively, and lamp lighting control means (light source lighting control means). ) 19, the lamp can be selected and turned on arbitrarily.

  Further, the optical sensor A (light source light quantity measuring means) 15 and the optical sensor B (light source light quantity measuring means) 18 are sensors capable of independently detecting the light quantities of the lamp A14 and the lamp B17, respectively. The lamp lighting control means 19 includes a circuit for lighting the lamp and a means for determining the lamp to be lit. The lamp lighting control means 19 acquires light amount information from the optical sensor A15 and the optical sensor B18, and performs predetermined arithmetic processing on the light amount information. Depending on the calculation result, drive control of the lamp A drive means (light source drive means) 13 and / or the lamp B drive means (light source drive means) 16 is performed.

  FIG. 2 is an internal detailed block diagram of the lamp lighting control means 19 of FIG. The detection of light amount data from each of the optical sensors A15 and B18 is managed by a light amount history management (light source light amount management means) 20. Here, several recently acquired light quantity data are stored in the memory (storage means) 23, the measurement history is read out as necessary, and the lamp A and B history management such as calculation of the light quantity attenuation rate is performed. The lamp lighting control (light source selection lighting control means) 21 determines which lamp A or lamp B is to be lit using information from the light amount history management 20 and an external lighting mode setting, and a lamp A driving circuit. The lighting command is transmitted to the lamp B driving circuit. Here, the lighting mode setting is a setting of “two-lamp lighting mode” in which both lamp A and lamp B are lit, or “one-lamp lighting mode” in which either lamp A or lamp B is lit.

  Detailed processing of the light quantity history management 20 and the lamp lighting control 21 will be described in the next processing flow. Next, specific processing of the lamp lighting control means 19 will be described with reference to processing flowcharts (FIGS. 4 and 5).

[STEP 0]
This is a wait state for a “lamp lighting start command” from the lamp non-lighting state or a “lamp lighting mode change command” from the lamp lighting state.

[STEP 1]
◇ After “Lamp lighting start command” or “Lamp lighting mode change command”, check the lamp lighting mode and perform branch processing according to the lighting mode.
It is determined whether the lamp lighting mode is “two-lamp lighting mode” or “one-lamp lighting mode”. If it is the “2-lamp lighting mode”, the process proceeds to [STEP 2]. If it is the “1-lamp lighting mode”, the process proceeds to [STEP 4] in FIG.

[STEP 2]
◇ Turn on both lamp A and lamp B.
In general, many lamps require a stabilization time (t0) until the light intensity becomes constant after lighting. Therefore, the light quantity measurement is not performed until a certain time (t0) elapses.
◇ Wait until the fixed time (t0) elapses. If the fixed time (t0) elapses, move to [STEP 3]

[STEP 3]
◇ The light quantity information from the optical sensors A and B is acquired by the optical quantity history management 20.
Light intensity of photosensor A: L_A [n]
Light intensity of photo sensor B: L_B [m]
(Here, n and m indicate the number of measurements.)
And These pieces of information are stored in the memory 23 for recent several times (α times).
At this time, on the memory 23,
Light amount data of optical sensor A: L_A [n], L_A [n-1], L_A [n-2], ..., L_A [n-α]
Light intensity data of optical sensor B: L_B [m], L_B [m-1], L_B [m-2], ..., L_B [m-α]
Is stored.
After acquiring the light amount data by the light amount history management 20 and storing the light amount data in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command, and proceeds to [STEP 0].

[STEP 4]
In STEP 1, processing is performed when “one lamp lighting mode” is selected in the “lamp lighting mode change command” or “lamp lighting start command”.
◇ The lifetime of each lamp is calculated from the past photosensor light quantity data stored in the memory 23.
A specific example of life calculation is shown below.
First, the light sensor data of the past several times of each lamp Light amount data of the optical sensor A: L_A [n], L_A [n-1], L_A [n-2], ..., L_A [n-α]
Light intensity data of optical sensor B: L_B [m], L_B [m-1], L_B [m-2], ..., L_B [m-α]
Is read.
An approximate function is generated from these α light quantity data. Each approximation function
y = f_a (x) (Optical sensor A) y = f_b (x) (Optical sensor B)
(Where x: projection time y: light intensity)
And
Further, the light quantity values of the light sensors in the initial state of the lamps A and B are assumed to be L_A0 and L_B0. (This information is memorized in advance)
At this time, x (time) when the output y of the approximate function is 20% of the light quantity values L_A0 and L_B0 is set as the lifetime.
FIG. 3 is a diagram showing the relationship between the approximate function and the calculated lifetime. FIG. 3A is an example of a lamp having a long life, and FIG. 3-B is an example of a lamp having a short life. Using the above method,
Estimated life of lamp A: LT_A
Estimated life of lamp B: LT_B
Is calculated. Here, the approximate function is used for the lifetime calculation, but it is not limited thereto. Moreover, although the light quantity value 20% attenuation from the initial state is described as the lifetime, it is not limited to that.

[STEP 5]
◇ Compare the estimated life of each lamp calculated in [STEP4], and determine the lamp to be turned on according to the result. Turn on the lamp with the longer estimated life.
When LT_A> LT_B When lamp A has a longer estimated life than lamp B (when the light quantity attenuation rate is small), lamp A is turned on.
When LT_A <LT_B If lamp B has a longer estimated life than lamp A, lamp B is lit.

[STEP 6a]
Wait until a certain time (t0) elapses after the lamp A is lit (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor A is acquired.
Light intensity of photosensor A: L_A [n]
(Here, n indicates the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23. At this time, the oldest data stored in the memory 23 is erased.
That is, the memory 23 always stores light amount data for the latest several times (α).
After the light amount data is acquired by the light amount history management 20 and stored in the memory 23, the process waits for a lamp lighting mode change command or a lamp lighting start command, and proceeds to [STEP 0].

[STEP 6b]
Wait until a certain time (t0) elapses after lamp B is lit (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor B is acquired.
Light intensity of photo sensor B: L_B [m]
(Here, m is the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23.
After acquiring the light amount data by the light amount history management 20 and storing the light amount data in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command. Move to [STEP0].

  As described above, in this embodiment, the brightness of each lamp is sensed (detected) at any time, and the estimated life (amount of light attenuation) is calculated from the data to thereby determine the lamp to be lit in the single lamp lighting mode. Then, control is performed to turn on the lamp having the longer estimated life (smaller light amount attenuation rate).

Next, what kind of improvement effect is obtained by performing the lighting selection control as described above will be described. FIGS. 6A and 6B are diagrams showing the difference in brightness of the projected video when the control of this embodiment is performed and when it is not performed. In this example, the projection is performed in a two-lamp lighting mode after a predetermined time (1000 h in this example) is projected in the one-lamp lighting mode. Here, it is assumed that the lamp A has a long life of 80% light quantity after 1000h projection, and the lamp B has a short life of 50% light quantity after 1000h projection. FIG. 6A shows an example of a change in the amount of light when the lamp A having a long estimated life is turned on in the single lamp lighting mode as in this embodiment. According to this, the brightness when projecting in two-lamp lighting mode after 1000h is
0.8 × L_A0 + L_B0 ―――――――――― (1)
It is.

On the other hand, FIG. 6B shows an example of the change in the amount of light when the lamp B having a short estimated life is turned on in the one-lamp lighting mode, unlike the present embodiment. According to this, the brightness when projecting in two-lamp lighting mode after 1000h is
L_A0 + 0.5 × L_B0 ―――――――――― (2)
It is. Since it can be said that there is not much difference between the initial light amounts of the lamp A and the lamp B, if L_A0≈L_B0, it can be said that (1) is brighter than (2). That is, when there are many forms using both the one-lamp lighting mode and the two-lamp lighting mode, it can be understood that a bright state can be maintained for a long time in the two-lamp lighting mode by performing the processing of this embodiment.

[Example 2]
FIG. 7 is a principal block diagram of the configuration of the projector according to the second embodiment of the present invention. The difference from the first embodiment is the configuration of the lamp lighting control means (light source lighting control means) 30. FIG. 8 is an internal detailed block diagram of the lamp lighting control means 30 of FIG. The light quantity history management 20 has the same function as that of the first embodiment, and is a block for recording and managing light quantity data acquired from the optical sensor A and the optical sensor B. In the second embodiment, the function of the lamp lighting control (light source selection lighting control means) 31 included in the lamp lighting control means 30 is different from that in the first embodiment.

  The lamp lighting control 31 performs the following operation (a) according to information from the optical sensor A15 and the optical sensor B18, an external lighting mode setting, and a video mode setting from the external projection mode setting means 30. Perform (c).

Operation (a) Decide whether to turn on lamp A or lamp B Depending on the result of operation (b) and operation (a), send a lighting command to the lamp A drive circuit and lamp B drive circuit. c) Gamma and gain settings for the video signal processing unit 10 are performed.

  Here, the lighting mode setting is a setting of “two-lamp lighting mode” in which both lamp A and lamp B are lit, or “one-lamp lighting mode” in which either lamp A or lamp B is lit. The mode setting from the projection mode setting means 30 from the outside is a setting such as “long life mode” (life priority mode) emphasizing brightness and “cinema mode” (brightness non-priority mode) emphasizing contrast. is there. The operation (c) is different from the first embodiment.

  Next, specific processing of the lamp lighting control 30 that is a feature of the present embodiment will be described with reference to processing flowcharts (FIGS. 9 and 10). Here, the processing flow in the two-lamp lighting mode is the same as that in FIG.

[STEP 0]
This is a wait state for a “lamp lighting start command” from the lamp non-lighting state or a “lamp lighting mode change command” from the lamp lighting state.

[STEP 1]
This is a process when “one lamp lighting mode” is selected in the “lamp lighting mode change command” or “lamp lighting start command”.
At this time, the branching process is performed with the projection video mode set to “long life mode” or “cinema mode”. Here, the “long life mode” is a mode in which the brightness of the lamp can be maintained for a long period of time, and the “cinema mode” is a mode in which the brightness and the contrast are important without requiring much brightness. And
If the video mode specified by the user is "Long Life Mode", move to [STEP 2].
If it is “Cinema mode”, move to [STEP 5].
STEP2 to STEP4a in the “long life mode” are the same as STEP4 to STEP6a in FIG.

[STEP 2]
◇ The lifetime of each lamp is calculated from the past photosensor light quantity data stored in the memory 23.
A specific example of life calculation is shown below.
First, the light sensor data of the past several times of each lamp Light amount data of the optical sensor A: L_A [n], L_A [n-1], L_A [n-2], ..., L_A [n-α]
Light intensity data of optical sensor B: L_B [m], L_B [m-1], L_B [m-2], ..., L_B [m-α]
Is read.
An approximate function is generated from these α light quantity data. Each approximation function
y = f_a (x) (Optical sensor A) y = f_b (x) (Optical sensor B)
(Where x: projection time y: light intensity)
And
Further, the light quantity values of the light sensors in the initial state of the lamps A and B are assumed to be L_A0 and L_B0. (This information is memorized in advance)
At this time, x (time) when the output y of the approximate function is 20% of the light quantity values L_A0 and L_B0 is set as the lifetime.

Using the above method,
Estimated life of lamp A: LT_A
Estimated life of lamp B: LT_B
Is calculated. Here, the approximate function is used for the lifetime calculation, but it is not limited thereto. Moreover, although the light amount attenuation of 20% from the initial state is described as the lifetime, it is not limited to that.

[STEP 3]
◇ Compare the estimated life of each lamp calculated in [STEP2], and determine the lamp to be turned on according to the result. Turn on the lamp with the longer estimated life.
When LT_A> LT_B When lamp A has a longer estimated life than lamp B, lamp A is turned on.
When LT_A <LT_B If lamp B has a longer estimated life than lamp A, lamp B is lit.

[STEP 4a]
Wait until a certain time (t0) elapses after the lamp A is lit (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor A is acquired.
Light intensity of photosensor A: L_A [n]
(Here, n indicates the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23. At this time, the oldest data stored in the memory 23 is erased.
That is, the memory 23 always stores light amount data for the latest several times (α).
After the light amount data is acquired by the light amount history management 202 and the light amount data is stored in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command. Move to [STEP0].

[STEP 4b]
Wait until a certain time (t0) elapses after lamp B is lit (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor B is acquired.
Light intensity of photo sensor B: L_B [m]
(Here, m is the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23.
After acquiring the light amount data by the light amount history management 20 and storing the light amount data in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command. Move to [STEP0].

  As described above, in the present embodiment, when the “long life mode” is selected, the brightness of each lamp is sensed at any time and the estimated life is calculated to light up in the single lamp lighting mode. The lamp is controlled so that the lamp having the longer estimated life is turned on.

[STEP 5]
This step is processing when a mode that does not require brightness (brightness non-priority mode) such as “cinema mode” is selected.
◇ Latest light quantity data (absolute light quantity) of each lamp from past light quantity data of light sensor stored in memory 23
Photosensor A light intensity data: L_A [n]
Photosensor B light quantity data: L_B [m]
Is read.
◇ Compare the above light quantities and determine which lamp is the darker as a result.
When L_A [n] <L_B [m] If Lamp A is darker than Lamp B, the process proceeds to [STEP 6a].
When L_A [n]> L_B [m] If the lamp B is darker than the lamp A, the process proceeds to [STEP 6b].

[STEP 6a]
In this step, the lamp to be lit is selected and the gain for signal processing is set.
Basically, the darker lamp is turned on, but if it is below a certain threshold (too dark), the brighter lamp is turned on. At this time, the brightness of the projected image does not differ depending on the lamp to be lit by reducing the gain by signal processing for the amount of light that has become brighter.
◇ Judge whether the brightness of the lamp A determined to be darker is above a certain threshold (LTH).
When L_A [n]> LTH When the brightness of lamp A is brighter than the specified brightness threshold (LTH)
Move on to [STEP 7a] (Lamp A lighting process).
When L_A [n] <LTH When the brightness of lamp A is darker than the predetermined brightness threshold (LTH)
The following gain calculation is performed and set for the video signal processing unit 10.
Gain = LTH ÷ L_B
Move to [STEP 7b] (Lamp B lighting process).

[STEP 6b]
◇ Judge whether the brightness of the lamp B judged to be darker is above a certain threshold (LTH).
When L_B [n]> LTH When the brightness of lamp B is brighter than the specified brightness threshold (LTH)
Move to [STEP 7b] (Lamp B lighting process).
When L_B [n] <LTH When the brightness of lamp B is darker than the predetermined brightness threshold (LTH)
The following gain calculation is performed and set for the video signal processing unit 10.
Gain = LTH ÷ L_A
Move on to [STEP 7a] (Lamp A lighting process).
Here, the threshold (LTH) is owned as a fixed value in consideration of the usage environment of the video mode in advance.

[STEP 7a]
◇ Control the lighting of lamp A.
Wait until a certain time (t0) elapses after lighting (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor A is acquired.
Light intensity of photosensor A: L_A [n]
(Here, n indicates the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23. At this time, the oldest data stored in the memory 23 is erased.
After acquiring the light amount data by the light amount history management 20 and storing the light amount data in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command. Move to [STEP0].

[STEP 7b]
◇ Control the lighting of lamp B.
Wait until a certain time (t0) elapses after lighting (wait until the light intensity stabilizes)
If the predetermined time (t0) has elapsed, the light amount of the optical sensor B is acquired.
Light intensity of photo sensor B: L_B [n]
(Here, n indicates the number of measurements.)
The light amount data acquired by the light amount history management 20 is stored in the memory 23. At this time, the oldest data stored in the memory 23 is erased.
After acquiring the light amount data by the light amount history management 20 and storing the light amount data in the memory 23, it waits for a lamp lighting mode change command or a lamp lighting start command. Move to [STEP0].

  As described above, in the second embodiment, the darker lamp is turned on in the projection mode that does not require brightness as in the “cinema mode”. However, if it is too dark, the brighter lamp is turned on and the gain of signal processing is set so that the brightness of the projected image does not differ depending on the lamp to be turned on.

  According to each of the embodiments described above, it is possible to easily extend the life of the lamp by efficiently using the lamp according to the situation.

10: Video signal processing circuit, 11: Panel drive circuit, 13, 16: Lamp drive circuit, 14, 17: Light source such as high-pressure mercury lamp, 15, 18: Optical sensor, 12: Display panel such as liquid crystal, 19, 30 : Lamp lighting control block, 20: Light intensity history management block, 21, 30: Lamp lighting control block, 23: Storage means such as memory

Claims (4)

In an image projection apparatus for projecting an image illuminated with a light beam when one or a plurality of light sources among a plurality of light sources is turned on,
Comprising light source lighting control means for driving each of the plurality of light sources,
The light source lighting control means is
A light source light quantity measuring means for measuring the light quantity emitted from the plurality of light sources;
Storage means for storing a measurement history of the light source light quantity measurement means;
A light source light quantity management means for managing the plurality of light sources by obtaining a light quantity attenuation rate of each light source from the light quantities emitted from the plurality of light sources measured by the light source light quantity measurement means;
Have
When the light source lighting control unit selects and turns on a part of the plurality of light sources, the light source with a small light amount attenuation rate among the light sources obtained by the light source light amount management unit is preferentially controlled over other light sources. An image projection apparatus characterized by: A projection mode setting means for setting a projection mode for projecting the image, the light source lighting control means, on the basis of further information from the projection mode setting means, selecting some of the plurality of light sources The image projection apparatus according to claim 1, wherein the image projection apparatus is turned on. The light source light quantity management means obtains the light quantity attenuation amount of each light source from the light quantities emitted from the plurality of light sources measured by the light source light quantity measurement means, or determines the light quantity of each light source from the light quantities emitted from the plurality of light sources. The image projection apparatus according to claim 2 , wherein the plurality of light sources are managed by obtaining an absolute light amount. The projection mode setting means includes a life priority mode for maintaining the brightness of the light flux emitted from the light source for a long period of time, and a brightness for giving priority to other items over maintaining the brightness for a long period of time. Non-priority mode, and when the life priority mode is selected by the projection mode setting means, the light source lighting control means selects a light source having a small light quantity attenuation rate among the light sources obtained by the light source light quantity management means. preferentially lighting control from the light source, the when the brightness non-priority mode is selected by the projection mode setting means, the absolute quantity of light in the light source light quantity management unit, lighting towards the light source less the absolute amount preferentially The image projection apparatus according to claim 2 , wherein the image projection apparatus is controlled.