WO2016098729A1

WO2016098729A1 - Light source device, projector, and method for controlling light source device

Info

Publication number: WO2016098729A1
Application number: PCT/JP2015/084942
Authority: WO
Inventors: 三浦　雄一
Original assignee: ウシオ電機株式会社
Priority date: 2014-12-18
Filing date: 2015-12-14
Publication date: 2016-06-23
Also published as: JP2016119150A

Abstract

Provided is a light source device capable of maintaining brightness and chromaticity at fixed levels during a predetermined time period. The light source device is provided with a plurality of light sources having mutually different colors of light to be emitted, a light-detecting unit for individually detecting the amount of light emitted from the plurality of light sources, and a control unit for controlling the amount of light emitted from the plurality of light sources by adjusting the electric current supplied to the plurality of light sources. The control unit carries out: a first control in which the values of a target amount of light and a first threshold electric current are stored for each of the plurality of light sources, the detected amount of light detected by the light-detecting unit and the target amount of light are compared for each color, and the electric current supplied to each of the plurality of light sources is adjusted so that the detected amount of light matches the target amount of light; and a second control in which the value of the target amount of light after the completion of the first control is reduced when the electric current supplied to at least one of the light sources exceeds the first threshold electric current during the first control.

Description

Light source device, projector, and light source device control method

The present invention relates to a light source device, and more particularly, to a light source device including a plurality of light sources having different colors of emitted light. The present invention also relates to a projector including such a light source device and a method for controlling the light source device.

Development of devices using solid-state light sources such as LEDs and laser elements (LDs) instead of conventional lamps as a light source for projection projectors used for movies, home theaters, and the like is underway.

The projector has a function of displaying a desired image by projecting light emitted from the light source onto a distant screen by a projection optical system. Here, when the amount of light emitted from the light source changes, the observer recognizes that the illuminance of the video image displayed on the screen has changed. Therefore, in a light source device used for a projector, control is normally performed to keep the light quantity emitted from the light source constant.

Since the light source deteriorates with time, the illuminance decreases when the same amount of current is supplied. Therefore, for example, in order to detect the amount of light, a part of the optical path is divided to extract a part of the light, and feedback control is performed to adjust the amount of current to the light source so that the extracted amount of light indicates a predetermined amount of light. Is called.

Here, when a lamp is used as a light source as in the prior art, since the light emitted from the light source is white light, even if the amount of light emitted from the light source is reduced, the illuminance is simply reduced, and the color balance is Still retained. However, when using a solid-state light source as a light source, it is necessary to prepare a different light source for each color, and each light source uses a phenomenon that emits light based on a different composition and principle, so that deterioration occurs for each color. The degree is different. For this reason, it is necessary to maintain the chromaticity (color balance) as well as the illuminance by performing the feedback control for each color. As such a technique, for example, one described in Patent Document 1 below is known.

Japanese Patent No. 4792665

Patent Document 1 discloses a light source control device including a plurality of light sources composed of R, G, and B color laser elements and detection means for detecting a light output value for each color. The light source control device includes control means for performing control so that the light output values of the plurality of light sources are always constant based on the detection result of the detection means. As described above, when the deterioration of the light source progresses, it is necessary to increase the amount of current supplied to the light source in order to emit the target amount of light, and the control unit performs such control.

By the way, a solid state light source such as a laser element has a property that a physical property value changes when a current exceeding a predetermined current amount is supplied. For example, this value is defined as a rated current value. When the deterioration of the solid state light source element proceeds, the supply current to the solid state light source element increases when the above control is performed, and eventually reaches the rated current value. Even when a current amount corresponding to the rated current value is supplied to the solid-state light source element, the target light amount may not be realized. In order to avoid the occurrence of such a state, in the apparatus of Patent Document 1, when there is a light source that is likely to be supplied with a current exceeding a preset allowable maximum value, the light output of each light source It is configured to automatically switch from the control for making the value itself constant to the control for making the relative value of the light output of each light source constant. With such control, even when the light source deteriorates and a constant illuminance cannot be maintained, the relative intensities of R, G, and B can be kept constant, and the change in chromaticity can be suppressed. Has been.

However, when control is performed to keep the relative value of the light output of each light source constant as in the device described in Patent Document 1, the light output itself of each light source is kept constant even if the change in chromaticity is suppressed. As a result, the illuminance changes while the device is being driven. This means that, for example, when such a light source device is used as a light source for a video projector (projector), the illuminance decreases during the projection of the video. This means that the illuminance differs between the beginning and end of the projected image.

In view of the above problems, an object of the present invention is to realize a light source device capable of keeping illuminance and chromaticity constant within a predetermined period. It is another object of the present invention to provide a method for controlling such a light source device and a projector including such a light source device.

In order to solve the above problems, a light source device according to the present invention is:
A plurality of light sources having different colors of emitted light, and
A light detection unit that individually detects the amount of light emitted from the plurality of light sources;
A controller that controls the amount of light emitted from the plurality of light sources by adjusting the current supplied to the plurality of light sources;
The controller is
Each value of the target light amount and the first threshold current is stored for each of the plurality of light sources,
The detected light amount detected by the light detection unit and the target light amount are compared for each color, and the current supplied to each of the plurality of light sources is adjusted so that the detected light amount matches the target light amount Control
During the execution of the first control, when the current supplied to at least one of the light sources exceeds the first threshold current, the second control for reducing the value of the target light amount after the end of the first control. It is characterized by performing.

The control unit stores a value related to the target light amount for each color. While the first control is being executed, the current supply amount to each light source is adjusted so that the light amount detected by the light detection unit matches the target light amount.

Here, as described above, as the deterioration of the light source proceeds, the amount of current to be supplied to the light source increases so that the detected light amount matches the target light amount. In the light source device according to the present invention, information on a predetermined threshold value (first threshold current) is stored for each color in the control unit with respect to the current amount. Then, if the amount of current supplied to the light source exceeds the first threshold current during the first control, the control unit, after the first control is finished, Control to reduce the value of the amount of light. That is, after this, the value of the target light amount of each light source changes.

In such a configuration, since the target light amount does not change during the execution of the first control, the illuminance is kept constant during this period. That is, assuming that this light source device is used as a projection light source for a movie theater, the illuminance does not decrease during the screening by performing only the first control during the single screening period. During the screening, if the amount of current supplied to the light source of any color exceeds the first threshold current, for example, control is performed to reduce the target light amount after the screening ends, so the next screening period In, the first control is executed again under a target light amount lower than that during the previous screening. That is, the illuminance decreases when compared between different screening periods, but the illuminance does not decrease within one screening period, so the observer will not recognize that the illuminance has decreased during the screening. .

Further, when the current supplied to at least one light source exceeds the first threshold current, control is performed to reduce the target light amount value of each of the plurality of light sources as well as the light source. In other words, instead of reducing only the amount of current supplied to the light source that emits light of a specific color, the amount of current supplied to each light source is reduced, so the color before and after the target light amount is reduced. Can hold the degree. That is, the chromaticity of the projected image does not change within different projection periods.

In the above configuration, when the current supplied to at least one light source during the first control exceeds the first threshold current, the control unit preferably performs the second control immediately after the end of the first control. The present invention is not limited to this aspect. That is, even when the current supplied to at least one light source during the first control exceeds the first threshold current, the control unit performs the first control with the same target light quantity for the subsequent two or more times. You may perform 2nd control after performing. That is, the present invention performs the first control performed by the control unit immediately after the current supplied to at least one light source during the first control exceeds the first threshold current, or after 2-3 times, for example. The right control includes the case where the first control is executed with the same target light amount value, and then the control unit executes the first control under the target light amount that is reduced by executing the second control.

Here, the value of the first threshold current is set to a value lower than the rated current described above. More specifically, the first threshold current corresponds to a rated current in each of the plurality of light sources or a maximum current that can be supplied to each of the plurality of light sources within a range that does not affect physical characteristics. The value can be lower than the two threshold current.

By setting the value of the first threshold current in this way, control is performed to increase the amount of current supplied to the light source in order to output the target light amount during the period in which the first control is being executed. Even if it is performed, it can be adjusted so as not to exceed the allowable maximum current value (second threshold current) that affects the element characteristics. Therefore, during the period in which the first control is performed, each light source can emit a target amount of light, and the illuminance and chromaticity can be maintained at desired values.

In the light source device,
The controller is configured to repeat a cycle of stopping the first control over a second period a plurality of times after performing the first control over a first period,
When the first threshold current is supplied to the light source at the start of the first period, the first threshold current is the amount of current supplied to the light source within the first period. It may be set so as not to exceed the two threshold currents.

According to the above configuration, the amount of current supplied to the light source can be reliably set to be equal to or less than the second threshold current within each first period. For example, by setting the first period as the screening period, the illuminance and chromaticity can be reliably kept constant during the screening of each movie. At this time, the second period can be an interval period between the screening of one movie and the screening of another movie.

In the light source device,
The control unit is configured so that a current supplied to the light source immediately after the start of the first control after the value of the target light amount is decreased by the second control is equal to or less than the first threshold current. It is also possible to set a reduction range of the value of the target light amount in the second control.

In such a configuration, in the state immediately after the first control is started after the target light amount is reduced by the second control, the amount of current supplied to each light source is lower than the first threshold current. Thereby, it can suppress that the electric current amount supplied with respect to each light source reaches a 2nd threshold current within the period when this 1st control is performed.

The projector according to the present invention is
It includes a light source device having any one of the above features and an optical system that projects light emitted from the light source device.

Further, the present invention is a method for controlling a light source device including a plurality of light sources having different colors of emitted light,
Each value of the target light amount and the first threshold current is stored for each of the plurality of light sources,
The amount of light emitted from the plurality of light sources is detected separately, and the detected amount of light detected and the target amount of light are compared for each color so that the detected amount of light matches the target amount of light. A first control for adjusting the current supplied to each of the plurality of light sources;
During the execution of the first control, when the current supplied to at least one of the light sources exceeds the first threshold current, a second control for reducing the value of the target light amount after the end of the first control; It is characterized by including.

According to the light source device of the present invention, it is possible to keep the illuminance and chromaticity constant during a period in which the amount of light emitted from the light source is controlled to coincide with a predetermined target amount of light. For this reason, when such a light source device is used as a light source device for projection, the occurrence of a situation in which chromaticity or illuminance decreases during image projection is suppressed.

It is a block diagram which shows typically the structure of the projector containing a light source device. It is a flowchart which shows an example of the control content performed in the control part with which a light source device is provided. 6 is a graph schematically showing temporal changes in the amount of current supplied to each light source and the amount of light emitted from each light source within each control period. It is a block diagram which shows typically another structure of the projector containing a light source device.

The light source device and projector of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram schematically showing a configuration of a projector including the light source device of the present embodiment. A projector 10 shown in FIG. 1 includes a light source device 1 and an optical system 2 that projects light emitted from the light source device. FIG. 1 also shows a screen 3 on which an image from the projector 10 is projected.

The light source device 1 includes a light source unit 11, a light detection unit 12, and a control unit 13. The light source unit 11 includes a light source 11R that emits red light, a light source 11G that emits green light, and a light source 11B that emits blue light. Each light source (11R, 11G, 11B) includes a solid light source element such as an LED element or a laser diode element.

In addition, although this embodiment demonstrates the case where the light source part 11 is comprised with the light source which emits the light of 3 colors, it is not limited to 3 about the number of colors. Each light source may be configured to include a known wavelength conversion element in addition to the solid light source element. For example, the light source 11G includes a laser diode element that emits infrared light and a wavelength conversion element such as PPLN (Periodically Poled Lithium Niobat) that converts the wavelength of the infrared light to ½. You may be comprised by.

The light source unit 11 is driven and controlled by the control unit 13. More specifically, the light source unit 11 includes a power source for driving each light source, and the control unit 13 separately controls the amount of current supplied from the power source to each light source (11R, 11G, 11B). It is a configuration that can.

The light detection unit 12 is configured to be able to detect the amount of light emitted from each light source (11R, 11G, 11B). More specifically, the light detection unit 12 detects a part of the light emitted from the light source 11R, a light detection unit 12R that detects a part of the light emitted from the light source 11G, and a light source 11B. The light detection part 12B which detects a part of light inject | emitted from is provided.

In the embodiment shown in FIG. 1, a partially reflecting mirror 14R is installed on the optical path of the light emitted from the light source 11R toward the optical system 2, and the light reflected through the mirror 14R is directed toward the light detection unit 12R. This is a configuration that proceeds. The same applies to green light and blue light. A partially reflecting mirror 14G is installed on the optical path of the light emitted from the light source 11G toward the optical system 2, and the light reflected through the mirror 14G travels toward the light detection unit 12G. A partially reflecting mirror 14B is installed on the optical path of the light emitted from the light source 11B toward the optical system 2, and the light reflected through the mirror 14B travels toward the light detection unit 12B.

As described above, when the light detection unit 12 detects the amount of light emitted from each light source (11R, 11G, 11B) separately, it gives the control unit 13 information on the detected light amount. The control unit 13 stores a target light amount value and a predetermined threshold current (corresponding to “first threshold current”) for each of the light sources (11R, 11G, and 11B).

Hereinafter, the control contents performed by the control unit 13 will be described with reference to the flowchart shown in FIG.

When the light source device 1 is turned on, control by the control unit 13 is started. The control unit 13 first determines whether or not it is necessary to change the value of the target light amount (step S1). Here, the case where there is no need to change the value of the target light amount (No in step S1) will be described first. The case where the target light amount value needs to be changed will be described after the step of changing the target light amount value.

The control unit 13 reads the value of the target light amount stored for each color (step S2A). And the control part 13 acquires the value of the detected light quantity for every color from the light detection part 12 (12R, 12G, 12B) (step S3). And the control part 13 compares the value of the target light quantity read by step S2 with the value of the detected light quantity acquired by step S3 for every color (step S4).

And the control part 13 adjusts the electric current amount supplied with respect to the light source (11R, 11G, 11B) for every color so that the value of detected light quantity may correspond with the value of target light quantity (step S5). That is, the control unit 13 compares the detected light amount value with the target light amount value for each color, and if they match (Yes in step S4), does not change the amount of current supplied to the light source corresponding to the color. On the other hand, the control unit 13 compares the value of the detected light amount and the value of the target light amount for each color, and if they do not match (No in step S4), changes the amount of current supplied to the light source corresponding to the color. More specifically, if the detected light quantity is higher than the target light quantity, the control unit 13 performs control to reduce the amount of current supplied to the target light source, and the detected light quantity shows a value lower than the target light quantity. If so, the control unit 13 performs control to increase the amount of current supplied to the target light source.

Control unit 13 acquires the amount of current supplied to each light source (11R, 11G, 11B) separately (step S6). Then, the control unit 13 reads the value of the first threshold current amount stored for each color, and compares the magnitude relationship with the amount of current supplied to each light source acquired for each color in step S6 (step S7). ).

In all colors, when the amount of current supplied to each light source is equal to or less than the corresponding first threshold current (Yes in step S7), the control unit 13 repeatedly executes each step of steps S3-S7. On the other hand, when the supply current amount to the light source exceeds the corresponding first threshold current in at least one or more colors (No in step S7), the control unit 13 determines the next control period for the light source of the color. In step S8, the fact that the target light amount value is to be decreased is stored (step S8), and steps S3-S7 are repeated.

Here, for the sake of explanation, it is assumed that the values of the first threshold current set in the light source 11R, the light source 11G, and the light source 11B are RI1, GI1, and BI1, respectively. Further, it is assumed that the target light amount values set in the light source 11R, the light source 11G, and the light source 11B in the certain control period T1 are RL1, GL1, and BL1, respectively. Then, it is assumed that the current amount Ib supplied to the light source 11B exceeds the first threshold current BI1 set for the light source 11B at a predetermined time point in the control period T1. Further, it is assumed that the current amounts of the other light sources do not exceed the corresponding first threshold current value. That is, during this control period T1, the current amount Ir supplied to the light source 11R does not exceed the first threshold current RI1 set for the light source 11R, and the current amount Ig supplied to the light source 11G is equal to the light source 11G. A case is assumed where the first threshold current GI1 that has been set to is not exceeded.

In the above case, in step S8, the control unit 13 stores that the target light amount is reduced in the next control period (for convenience, “T2”). In this step S8, it is only stored that the target light amount is decreased in the next control period T2, and the target light amounts of the

light sources

11R, 11G, and 11B are still RL1, It remains GL1 and BL1.

When the control period T1 ends and the control of the light source device 1 is started again, that is, when the control period T2 is started, the control unit 13 firstly sets the target light amount of each light source (11R, 11G, 11B). It is determined whether or not it is necessary to change the value of (step S1). Here, since it is necessary to decrease the value of the target light amount (Yes in step S1), the control unit 13 decreases the value of the target light amount currently set for each light source (11R, 11G, 11B). Control is performed (step S2B).

Here, in the above-described example, only the current amount Ib supplied to the light source 11B exceeds the corresponding first threshold current BI1 within the control period T1, and the current supplied to the other light sources (11R, 11G). The amount (Ir, Ig) does not exceed the corresponding first threshold current (RI1, GI1). However, in step S2B of the control period T2, the control unit 13 performs control to reduce the value of the target light amount for all the light sources (11R, 11G, 11B). Here, the values of the target light amounts of the newly set

light sources

11R, 11G, and 11B are RL2, GL2, and BL2, respectively.

Hereinafter, as described above, the control unit 13 executes steps S3 to S8.

When the control unit 13 performs such control, the control unit 13 holds the light amount emitted from each light source (11R, 11G, 11B) at a predetermined light amount within a predetermined period. The fact that the illuminance and chromaticity can be maintained within the controlled period (within the control period) will be described with reference to the graph of FIG.

FIG. 3 is a graph schematically showing temporal changes in the amount of current supplied to each light source (11R, 11G, 11B) and the amount of light emitted from each light source within each control period. Here, as described above, in the control period T1, the supply current amount Ib of only the blue light source 11B exceeds the first threshold current BI1, and the supply current amount of the other light sources exceeds the first threshold current. Shall not. For example, this corresponds to a case where the blue light source 11B is more deteriorated than the other light sources (11R, 11G).

In FIG. 3, the control periods T0, T1, T2, and T3 are illustrated. That is, in FIG. 3, the supply current amount Ib does not exceed the first threshold current BI1 for the blue light source 11B in the control period T0, and the supply current amount Ib exceeds the first threshold current BI1 for the first time in the control period T1. It is shown.

In the control period T0, the amount of current Ib supplied to the light source 11B increases with time. This corresponds to the case where the deterioration of the light source 11B is progressing compared to the

light sources

11R and 11G. That is, if the light source (11R, 11G, 11B) deteriorates, the light emission amount under the same supply current amount decreases, so the supply current amount is increased to achieve the target light amount (RL1, GL1, BL1). Must. Since the deterioration of the element proceeds with the passage of time, the supply current amount in the light source 11B also increases with the passage of time. Note that, with respect to the

light sources

11R and 11G, since the element hardly deteriorates, the amount of current supplied to each light source (Ir, Ig) is almost constant.

Note that one control period can be, for example, from when the power source is turned on to the light source device 1 until when the power source is released. As another example, when the projector 10 is used for movie screening, one control period can be set as one movie screening period. In the latter case, for example, in a movie theater, a movie M0 is shown during the control period T0, and another movie M1 is shown during the next control period T1 after a predetermined interval. Can do.

As described above, in the example of this embodiment, the supply current amount Ib to the light source 11B exceeds the first threshold current BI1 within the control period T1. For this reason, in the next control period T2, the target light amounts of all the

light sources

11R, 11G, and 11B are decreased from RL1, GL1, and BL1 in the control period T1, respectively, and are set to RL2, GL2, and BL2. .

When the target light amount decreases, the amount of current that should be supplied to the light source in order to realize the light amount naturally decreases. This applies not only to the light source 11B but also to the light source 11R and the light source 11G. As for the light source 11R and the light source 11G, FIG. 3 shows that the amount of emitted light and the amount of supplied current in the control period T2 are lower than those in the control period T1, respectively.

And also in the light source 11B, the amount of supplied current and the amount of emitted light are lower in the control period T2 than in the control period T1. Here, in the present embodiment, as shown in FIG. 3, the current amount Ib supplied to the light source 11B is lower than the first threshold current BI1 within the control period T2. That is, in this case, in the next control period T3, the target light amount of each light source (11R, 11G, 11B) is set to the same value as in the control period T2.

In the example of FIG. 3, the current amount Ib supplied to the light source 11B again exceeds the first threshold current BI1 in the control period T3. For this reason, after the end of the control period T3, the target light amount of (11R, 11G, 11B) of each light source is set to a value decreased from the control period T3.

As shown in FIG. 3, when a deteriorated light source (here, the light source 11B) is present, the rate of increase in the amount of current supplied to the light source is faster than other light sources. However, according to the light source device 1 of the present embodiment, when the amount of current supplied to the light source within the control period exceeds the first threshold current, the target light amount is reduced in the subsequent control period. The supply current amount at this time also decreases. As a result, the amount of current Ib supplied to the light source 11B can be prevented from reaching the second threshold current BI2. For the light sources (11R, 11G) that are not degraded or have not progressed, of course, the amount of supplied current does not reach the second threshold current.

In the light source device 1, the target light amount value is kept constant within each control period (T0, T1, T2, T3). Therefore, more specifically, while the control is being performed by the control unit 13, the control unit 13 controls the light amount emitted from each light source (11R, 11G, 11B) to be held at a predetermined light amount. Within the period, the amount of light emitted from each light source is kept constant. Therefore, the illuminance and chromaticity do not change within each control period.

Further, in the light source device 1, when the supply current amount exceeds the first threshold current for a certain light source (here, the light source 11 </ b> B) within a certain control period (here, the period T <b> 1), only this light source is used in the later control period. In addition, the target light amount is reduced for other light sources. This means that, when changing the target light amount, the ratio of the light emission amount from each light source can be kept constant or substantially constant. That is, chromaticity can be maintained over a control period (here, control periods T1 and T2) before and after the target light amount is changed.

According to this control method, the amount of emitted light is different between the control period T1 and the control period T2, and thus when used as the projector 10, the illuminance of the image projected on the screen 3 is different. However, when each control period corresponds to a movie screening period, for example, according to the projector 10 of the present invention, the illuminance of the image does not change during the movie screening. The observer does not recognize that the illuminance has decreased during the screening.

As described above, the information regarding the first threshold current (RI1, GI1, BI1) may be stored in advance by the control unit 13. Here, the value of each first threshold current depends on the rising speed of the supply current amount when each light source (11R, 11G, 11B) deteriorates and the length of the assumed control period (T1, T2, etc.). Can be set in advance. For example, when the light source device 1 is used as a light source for the projector 3 and the projector 3 is used in a movie theater, each control period corresponds to one movie showing time as described above. The movie show time is generally configured within an approximate range (for example, 1.5 hours to 4 hours). Therefore, immediately after the start of the control period, when the amount of current supplied to the light source is the value of the first threshold current, at the end of the control period, the amount of current supplied to the light source falls below the second threshold current. It is preferable to set the value of the first threshold current.

Furthermore, as the reduction width of the target light amount of each light source (11R, 11G, 11B) in step S2B, for example, the current supplied to the light source immediately after the control is started under the reduced target light amount is equal to or less than the first threshold current. It is preferable to set so as to be. This is because the amount of current supplied to the deteriorated light source can be reduced to a range that does not approach the second threshold current by using a new target light amount.

In addition, a well-known optical system can be used for the structure of the optical system 2 with which the projector 10 shown in FIG. 1 is provided. As an example, the projector 10 includes a spatial modulation element 21 (21R, 21G, 21B) that converts light emitted from each light source (11R, 11G, 11B) into an optical image, and a light image emitted from each spatial modulation element 21. A color synthesizing optical system 22 for synthesizing and a projection optical system 23 for enlarging and projecting the light image emitted from the color synthesizing optical system 22 onto the screen 3 are configured. The spatial modulation element 21 is composed of, for example, a digital micromirror device or a liquid crystal display device, the color composition optical system 22 is composed of a color composition prism such as a dichroic prism, and the projection optical system 23 is composed of, for example, a projection lens. The

In the above-described embodiment, the case where only the blue light source 11B is deteriorated has been described. However, the same discussion is possible for other colors, and thus the description thereof is omitted.

[Another embodiment]
In the following, another embodiment will be described.

<1> As shown in FIG. 4, filters (16R, 16G, 16B) in which the light detection unit 12 (12R, 12G, 12B) transmits light of a target color and does not transmit light of other colors. It can be set as the structure provided with. In this case, the light source device 1 includes the

dichroic mirrors

15R and 15G and the partial reflection mirror 14B, so that a part of the light emitted from each light source (11R, 11G, and 11B) is superimposed. It does not matter even if it proceeds to the light detection unit 12. Even in this case, the

light detection units

12R, 12G, and 12B can detect the amounts of light corresponding to the amounts of light emitted from the

light sources

11R, 11G, and 11B, respectively.

<2> In the embodiment described above, when the amount of current supplied to the light source 11B exceeds the first threshold current BI1 in the control period T1, the target light amount of each of the

light sources

11R, 11G, and 11B in the next control period T2. Has been described for the case of lowering than the control period T1. Although it is preferable to perform such control in the control part 13, the control content which the light source device 1 which concerns on this invention performs is not restricted to this aspect. For example, in the above example, the amount of current supplied to the light source 11B in the control period T1 exceeds the first threshold current BI1, but not the control period T2 immediately after, but the next control period T3 or more. The target light amount may be decreased for the first time within the control period after several times.

1: Light source device 2: Optical system 3: Screen 10: Projector 11:

Light source unit

11R, 11G, 11B: Light source 12:

Light detection unit

12R, 12G, 12B: Light detection unit 13:

Control unit

14R, 14G, 14B: One

Partial reflection mirror

15R, 15G:

Dichroic mirror

16R, 16G, 16B: Filter 21:

Spatial modulation element

21R, 21G, 21B: Spatial modulation element 22: Color synthesizing optical system 23: Projection optical system

Claims

A plurality of light sources having different colors of emitted light, and
A light detection unit that individually detects the amount of light emitted from the plurality of light sources;
A controller that controls the amount of light emitted from the plurality of light sources by adjusting the current supplied to the plurality of light sources;
The controller is
Each value of the target light amount and the first threshold current is stored for each of the plurality of light sources,
The detected light amount detected by the light detection unit and the target light amount are compared for each color, and the current supplied to each of the plurality of light sources is adjusted so that the detected light amount matches the target light amount Control
When the current supplied to at least one of the light sources exceeds the first threshold current during execution of the first control, the value of the target light amount of each of the plurality of light sources after the end of the first control. A second light source device for reducing the light is performed.
The first threshold current is higher than a second threshold current corresponding to a maximum current that can be supplied to each of the plurality of light sources within a range that does not affect a rated current or physical characteristics of each of the plurality of light sources. The light source device according to claim 1, wherein the light source device has a low value.
The controller is configured to repeat a cycle of stopping the first control over a second period a plurality of times after performing the first control over a first period,
When the first threshold current is supplied to the light source at the start of the first period, the first threshold current is the amount of current supplied to the light source within the first period. The light source device according to claim 2, wherein the light source device is set so as not to exceed two threshold currents.
The control unit is configured so that a current supplied to the light source immediately after the start of the first control after the value of the target light amount is decreased by the second control is equal to or less than the first threshold current. 4. The light source device according to claim 2, wherein a reduction range of the value of the target light amount in two controls is set.
The light source device according to any one of claims 1 to 4,
An optical system that projects light emitted from the light source device.
A method of controlling a light source device including a plurality of light sources having different colors of emitted light,
Each value of the target light amount and the first threshold current is stored for each of the plurality of light sources,
The amount of light emitted from the plurality of light sources is detected separately, and the detected amount of light detected and the target amount of light are compared for each color so that the detected amount of light matches the target amount of light. A first control for adjusting the current supplied to each of the plurality of light sources;
During the execution of the first control, when the current supplied to at least one of the light sources exceeds the first threshold current, a second control for reducing the value of the target light amount after the end of the first control; A control method for a light source device, comprising: