JP2014038129A - Image projection device, and control method and control program therefor - Google Patents

Abstract

An object of the present invention is to maintain an appropriate projection brightness regardless of the brightness performance of a replaced projection optical system, and to suppress wasteful power consumption and a shortened life of a light source.
An image projection apparatus 20 modulates light from a light source 4 with an image forming element 7 and projects an image onto a projection surface 15 through exchangeable projection optical systems 9 and 13 to display an image. The control unit 11 includes projections attached to the apparatus from storage units 12 and 14 that store optical system brightness information, which is information about the brightness of each of a plurality of projection optical systems that can be exchanged for the apparatus. Use optical system brightness information that is optical system brightness information corresponding to the optical system is read, and using the use optical system brightness information, the brightness of the projection light projected from the projection optical system onto the projection surface is The light output of the light source is controlled so as to achieve the target brightness set in common for the plurality of projection optical systems.
[Selection] Figure 1

Description

  The present invention relates to an image projection apparatus such as a liquid crystal projector capable of exchanging a projection optical system (for example, a projection lens).

  In an image projection apparatus capable of exchanging the projection lens, the brightness of the projection light projected on the projection surface from the mounted projection lens when the light output of the light source such as a lamp is the same (hereinafter referred to as projection brightness). ) Changes according to the brightness performance (for example, F number) of the projection lens. For this reason, when the light source emits light at the maximum light output regardless of the projection lens mounted as in the prior art, an image brighter than necessary may be projected when a bright projection lens with good performance is mounted. In this case, not only is the burden on the viewer viewing the image too bright, but also the power is wasted because the light source is caused to emit excessively. Furthermore, since the light source continues to be heavily loaded, the life of the light source is shortened.

  For example, in the image projection apparatus disclosed in Patent Document 1, in order to prevent a change in hue due to a change in projection luminance due to replacement of the projection lens, the projection brightness is reduced by a diaphragm provided in the projection lens. Increase or decrease.

Japanese Patent Laid-Open No. 06-14326

  However, in the image projection apparatus disclosed in Patent Document 1, the light output of the light source remains high because the diaphragm is only provided in the optical path from the light source to the projection lens to control the amount of light passing through the projection lens. Is done. For this reason, the problem of useless power consumption and shortening of the lifetime of a light source remains.

  Also, if the brightness of the surroundings of the device changes to dark while a projection lens without an aperture is attached and projects an image with appropriate brightness, replace it with a dark projection lens with low performance. And there is no choice but to reduce the projection brightness. For example, this corresponds to the case where the room in which the image projection apparatus is installed is turned off or the apparatus is moved from a bright room to a dark room.

  The present invention provides an image projection apparatus capable of maintaining an appropriate projection brightness regardless of the brightness performance of the replaced projection optical system, and suppressing wasteful power consumption and shortening of the lifetime of the light source, and the image projection apparatus Provide a control method.

An image projection apparatus according to an aspect of the present invention displays an image by modulating light from a light source by an image forming element and projecting the light onto a projection surface through a replaceable projection optical system. The apparatus has control means for controlling the light output of the light source. The control means is attached to the apparatus from storage means that stores optical system brightness information, which is information about the brightness of each of a plurality of projection optical systems that can be exchanged for the apparatus, individually or collectively. Use optical system brightness information that is optical system brightness information corresponding to the projection optical system is read, and the brightness of the projection light projected from the projection optical system onto the projection surface is determined using the use optical system brightness information. The light output of the light source is controlled so that the target brightness is set in common for a plurality of projection optical systems.

  According to another aspect of the present invention, there is provided a control method in which light from a light source is modulated by an image forming element and projected onto a projection surface through a replaceable projection optical system to display an image. Applies to The control method includes a step of preparing optical system brightness information, which is information relating to the brightness of each of a plurality of projection optical systems that can be exchanged for the image projection apparatus, and the image projection apparatus among the optical system brightness information. The brightness of the projection light projected from the projection optical system onto the projection surface is set in common for the plurality of projection optical systems using the used optical system brightness information corresponding to the projection optical system mounted on And controlling the light output of the light source so as to achieve the target brightness.

  Furthermore, a control program according to another aspect of the present invention provides an image projection apparatus that displays an image by modulating light from a light source by an image forming element and projecting the light onto a projection surface through a replaceable projection optical system. Is a computer program that causes a computer provided in to execute an operation including the following steps. The control program is mounted on the apparatus from storage means that stores optical system brightness information, which is information about the brightness of each of a plurality of projection optical systems that can be exchanged for the image projection apparatus, individually or collectively. The used optical system brightness information, which is optical system brightness information corresponding to the projected optical system, and the used optical system brightness information, and the projection light projected from the projection optical system onto the projection surface And controlling the light output of the light source so that the brightness becomes a target brightness set in common for the plurality of projection optical systems.

  In the present invention, the light output of the light source is controlled so that the projection brightness becomes the target brightness common to the plurality of projection optical systems using the used optical system brightness information. Therefore, according to the present invention, it is possible to maintain an appropriate projection brightness regardless of the brightness performance of the mounted projection optical system, and it is possible to prevent wasteful power consumption and shortening of the lifetime of the light source.

1 is a block diagram illustrating a configuration of a projector that is Embodiment 1 of the present invention. FIG. 6 is a flowchart illustrating the operation of the projector according to the first embodiment. FIG. 5 is a block diagram illustrating a configuration of a projector that is Embodiment 2 of the present invention. 9 is a flowchart showing the operation of the liquid crystal projector of Embodiment 2. FIG. 6 is a block diagram illustrating a configuration of a projector that is Embodiment 3 of the present invention. 10 is a flowchart showing the operation of the liquid crystal projector of the third embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the configuration of a projector 20 as an image projection apparatus that is Embodiment 1 of the present invention. Reference numeral 1 denotes an AC-DC power source, which generates a plurality of DC (direct current) power sources from AC (alternating current) which is a commercial power source, and supplies it to each circuit inside the projector. An AC plug 2 connects the AC-DC power source 1 to a commercial power outlet (not shown).

  Reference numeral 3 denotes a ballast power source (hereinafter simply referred to as a ballast), which generates a lamp lighting power (voltage and current) using a DC power source supplied from the AC-DC power source 1 and supplies this to a lamp 4 as a light source. Supply. The power for lighting the lamp is hereinafter referred to as lamp power. As the lamp 4, a discharge light-emitting lamp such as an ultrahigh pressure mercury lamp or a xenon lamp is used. In addition, you may use light sources other than a lamp, such as LED, as a light source. By changing the lamp power, the light output of the lamp 4 (in other words, the light emission intensity or light emission amount of the lamp 4) can be changed.

  An external input interface 5 inputs a video signal supplied from the outside of the projector. The external input interface 5 outputs the input video signal to an image processing circuit 6 constituted by an IC or the like.

  The image processing unit 6 performs predetermined processing on the input video signal to generate an image signal that can drive the image forming panel 7 as an image forming element, and sends this to the panel driver 8. The image forming panel 7 is an element that can modulate light incident from the lamp 4 into image light for displaying an image, such as a reflective or transmissive liquid crystal panel or a digital micromirror device (DMD).

  The panel driver 8 drives the image forming panel 7 in accordance with the image signal input from the image processing unit 6. The same number of image forming panels 7 as a plurality of colors such as RGB (three in this embodiment) are provided. Each of the plurality of color lights separated from each other by the color separation optical system composed of a color separation element, a polarization separation element, and the like is incident on these image forming panels 7. The image forming panel 7 modulates incident color light into image light for each pixel. A plurality of colors of image light emitted from the plurality of image forming panels 7 are combined into one by a color combining optical system configured by a polarization separation element or the like to be full color image light, and pass through the inside of the lens mount 10. To the projection lens 9.

  Here, the projection lens 9 can be attached to and detached from the lens mount 10, and the projection lens 13 can also be attached to and detached from the lens mount 10. Further, although not shown, one or more projection lenses that can be attached to and detached from the lens mount 10 may be present. These projection lenses are a plurality of projection lenses (projection optical systems) that can be exchanged for the projector 20.

  A projection lens (a projection lens 9 in FIG. 1, hereinafter referred to as a used projection lens) mounted on the lens mount 10 enlarges and projects incident projection light as full-color image light onto a projection surface 15 such as a screen or a wall surface. To do. Thereby, a projection image as a full-color image is displayed on the projection surface 15.

  Reference numeral 11 denotes a controller (control means) configured as a computer including a CPU and the like. The controller 11 is electrically connected to a memory (12, 14) which is a storage means such as a ROM provided in the used projection lens (9 or 13) via an electrical contact group (not shown) provided in the lens mount 10. Connected. The controller 11 is also electrically connected to the ballast power source 3 and controls the lamp power supplied from the ballast power source 3 to the lamp 4 (by changing at least one of voltage and current), whereby the light output of the lamp 4 To control.

  The memories 12 and 14 individually store (prepare) lens brightness information (optical system brightness information), which is information regarding the individual brightness performance of the projection lenses 9 and 13 provided therein. The lens brightness information is, for example, an F number as a reciprocal of the aperture ratio, which is a value obtained by dividing the lens diameter by the focal length. The smaller the F number, the brighter the projection lens. In the present embodiment, the projection lenses 9 and 13 have different brightness performances. In other words, the projection lenses 9 and 13 have different optical configurations such as a lens diameter and a focal length. For this reason, the lens brightness information stored in the memory 12 and the lens brightness information stored in the memory 14 are also different from each other.

  Reference numeral 18 denotes a mode setting unit, which inputs a selection signal to the controller 11 in response to an operation for selecting a constant brightness mode, which will be described later, and other various operation modes (for example, a display mode) performed by the user. Further, in the mode setting unit 18, when the constant brightness mode is selected, the user sets the target projection brightness to be constant, that is, the target brightness that is commonly set for a plurality of projection lenses. Operation to set is possible. The projection brightness is the brightness of the projection light projected from the projection lens 13 onto the projection surface 15. The target brightness will be described later.

  In this embodiment, the controller 11 reads lens brightness information of the projection lens (hereinafter referred to as used lens brightness information) from the memory of the used projection lens, and uses the used optical system brightness information to project the projection brightness. The light output of the lamp 4 is controlled so that becomes the target brightness.

  Next, the operation (control method) of the projector will be described with reference to the flowchart of FIG. As described above, this operation is executed by the controller 11 as a computer in accordance with a control program as a computer program stored in an internal or external memory (not shown). This is the same in other embodiments described later.

  Here, the projection lens 9 mounted on the projector is removed from the lens mount (hereinafter simply referred to as “mount”) 10, and a projection lens 13 having a brightness performance different from that of the projection lens 9 is newly mounted on the mount 10. The case where it does is demonstrated. This also applies to other embodiments described later.

  In step S <b> 201, the controller 11 receives a lens mounting signal from a lens mounting sensor (not shown) provided on the mount 10 (or by communication with the projection lens 13 mounted on the mount 10), and the projection lens 13. Is mounted on the mount 10. Then, the process proceeds to step S202.

  In step S <b> 202, the controller 11 reads information on the optical performance of the projection lens 13 from the memory 14 provided in the projection lens 13 that is the used projection lens. This optical performance information includes lens brightness information of the projection lens 13. Then, the process proceeds to step S203.

  In step S203, the controller 11 uses the lens brightness information (used lens brightness information) of the projection lens 13 to obtain the light output of the lamp 4 necessary for setting the projection brightness to the target brightness. To calculate the lamp power to be output to the lamp 4.

  Here, the target brightness is an appropriate projection brightness that is neither too bright nor too dark as the brightness of the projected image observed by the user or the viewer. The target brightness can be set by the user through the mode setting unit 18 described above. For example, it is possible to select from a plurality of predetermined brightness levels such as standard brightness, brighter, brighter, darker, and darker. Further, the target brightness does not necessarily have to be brightness as one value, and may be brightness having a certain range. When the target brightness has a range, the lamp power for obtaining the target brightness also has a range. In the following description, lamp power for obtaining target brightness is referred to as target lamp power.

  Subsequently, in step S204, the controller 11 determines whether or not the constant brightness mode is selected (set) as the projection mode. If the constant brightness mode is set, the process proceeds to step S205. If the constant brightness mode is not set, the process proceeds to step S207, and the lamp power is not changed, in other words, the light output of the lamp 4 is changed. Continue projecting without

  On the other hand, the constant brightness mode is set, and when the process proceeds to step S205, the controller 11 determines whether or not the current lamp power is different from the target lamp power calculated in step S203. At this time, it may be determined that the lamp power is different from the target lamp power when the lamp power is different from the target lamp power by a predetermined value or more. If the lamp power is not different (same) as the target lamp power, the process proceeds to step S206, and if different, the process proceeds to step S208.

  In step S206, the controller 11 maintains the current lamp power. Then, the process proceeds to step S207, and projection is continued without changing the light output of the lamp 4.

  When the lamp power is different from the target lamp power and the process proceeds to step S208, the controller 11 determines whether or not the current lamp power can be changed, that is, whether the current lamp power is the upper limit value or the lower limit value. To do. If the current lamp power is lower than the target lamp power calculated in step S203 and the current lamp power is the upper limit value, it is determined that the lamp power cannot be changed (increased) and the process proceeds to step S207. Proceed and continue projection without changing lamp power. If the current lamp power is higher than the target lamp power and the current lamp power is the lower limit value, it is determined that the lamp power cannot be changed (decreased), and the process proceeds to step S207. Continue projecting without changing power.

  The current lamp power is not the upper limit when the current lamp power is lower than the target lamp power, and the current lamp power is not the lower limit when the current lamp power is higher than the target lamp power In the case, the process proceeds to step S209.

  In step S209, the controller 11 controls the ballast 3 so that the lamp power approaches the target lamp power. In step S205 again, it is determined whether or not the lamp power after the change is different from the target lamp power. If the lamp power becomes the same as the target lamp power by performing or repeating the processes of steps S205, S208, and S209 once, projection is continued with the changed lamp power in steps S206 and S207.

  As described above, in this embodiment, using the use lens brightness information obtained from the use projection lens, the target lamp power for setting the projection brightness to the target brightness is calculated, and the actual lamp power is set as the target lamp power. By controlling to be the same, the light output of the lamp 4 is changed. Specifically, when the used projection lens is replaced with a brighter projection lens, the lamp power is reduced to lower the light output of the lamp 4, and when the projection lens is replaced with a darker projection lens, the lamp power is increased to increase the lamp 4. Increase the light output. Thereby, it is possible to maintain an appropriate projection brightness regardless of the brightness performance of the used projection lens. Further, when a bright projection lens is attached, it is possible to suppress wasteful power consumption and shortening of the life of the lamp 4. The inventor has confirmed that the life of the ultra-high pressure mercury lamp is prolonged by lowering the supplied lamp power.

  In the present embodiment, a case has been described in which each projection lens (9, 13) is individually provided with a memory (12, 14) for storing lens brightness information of the projection lens. However, the projector 20 may be provided with an internal memory (storage means) that collectively stores lens brightness information of these projection lenses. In this case, the controller 11 reads out and uses the used lens brightness information stored in association with the identification information (model, serial number, etc.) of the projection lens obtained by communication with the used projection lens. What should I do?

  Further, similarly, an external memory (storage means) for storing lens brightness information of a plurality of projection lenses collectively may be provided so as to be detachable from the projector 20. In this case, when the use lens brightness information is necessary, the external memory is attached to the projector 20, and the use lens brightness information stored in association with the identification information obtained through communication with the use projection lens is stored in the external lens. What is necessary is just to read and use from a memory.

  FIG. 3 shows a configuration of a projector 30 as an image projection apparatus that is Embodiment 2 of the present invention. The basic configuration of the projector 30 of the present embodiment is the same as that of the projector 20 of the first embodiment, and the same components as those of the projector 20 of the first embodiment are denoted by the same reference numerals as in the first embodiment, and the description is omitted.

  The projector according to the present embodiment includes an external light measurement sensor 16. The ambient light measurement sensor 16 functions as an environmental brightness measurement unit that measures the environmental brightness, which is the brightness around the projector 30. The ambient light measurement sensor 16 is disposed at a position where the projection brightness (including the reflected light from the projection surface 15) of the projector 30 can be measured without incident.

  In this embodiment, the controller 11 reads the use lens brightness information from the memory of the use projection lens, and uses the use optical system brightness information and the ambient brightness measured by the external light measurement sensor 16 to project the projection brightness. The light output of the lamp 4 is controlled so that becomes the target brightness. If the light output of the same lamp 4 is set when the ambient brightness is bright, the projected brightness may not reach the target brightness. For this reason, in this embodiment, when the ambient brightness is bright, the lamp power is increased so that the light output of the lamp 4 is higher than when the ambient brightness is dark. On the other hand, if the light output of the same lamp 4 is set when the ambient brightness is dark, the projected brightness may be too high for the target brightness. For this reason, in this embodiment, when the environmental brightness is dark, the lamp power is reduced so that the light output of the lamp 4 is lower than when the environmental brightness is bright.

  Next, the operation of the projector will be described with reference to the flowchart of FIG. Steps S401, S402, and S404 to S409 in FIG. 4 are the same as steps S201, S202, and S204 to S209 in the first embodiment (FIG. 2), respectively, and thus description thereof is omitted.

  The controller 11 that has advanced from step S402 to step S410 drives the external photometric sensor 16 to measure the ambient brightness.

  Next, in step S411, the controller 11 reads the use lens brightness information from the memory (memory 14) of the use projection lens (projection lens 13). Then, the target lamp power for setting the projection brightness to the target brightness is calculated using the used optical system brightness information and the environmental brightness measured in step S410. And it progresses to the process after step S404.

  According to this embodiment, it is possible to maintain an appropriate projection brightness regardless of the brightness performance of the used projection lens and the environmental brightness. Further, when a bright projection lens is attached or when the environmental brightness is dark, it is possible to suppress wasteful power consumption and shortening of the life of the lamp 4.

  FIG. 5 shows a configuration of a projector 40 as an image projection apparatus that is Embodiment 3 of the present invention. The basic configuration of the projector 40 according to the present embodiment is the same as that of the projector 20 according to the first embodiment, and constituent elements common to the projector 20 according to the first embodiment are denoted by the same reference numerals as in the first embodiment and are not described.

  The projector of this embodiment has a reflected light photometric sensor 17. The reflected light photometric sensor 17 functions as reflected light measuring means for measuring the brightness of the reflected light reflected by the projection surface 15 of the projected light. The reflected light photometric sensor 17 is installed in the projector 40 at a position where it can directly receive the reflected light from the projection surface 15.

  In the present embodiment, the controller 11 reads the use lens brightness information from the memory of the use projection lens, and uses the use optical system brightness information and the brightness of the reflected light measured by the reflected light photometric sensor 17 to project. The light output of the lamp 4 is controlled so that the brightness becomes the target brightness. The light output of the same lamp 4 is set when the reflectance of the projection surface 15 is low (for example, when the wall surface of the room is used instead of the screen) and when it is high (for example, when a dedicated projection screen is used). Then, the projection brightness seen from the user may not reach the target brightness. For this reason, in this embodiment, when the brightness of the measured reflected light is low (when the reflectance of the projection surface 15 is low), the light output of the lamp 4 is higher than when it is high. Increase the lamp power. On the other hand, when the reflectance of the projection surface 15 is high and the light output of the same lamp 4 is set as when it is low, the projection brightness seen from the user may be too high for the target brightness. For this reason, in this embodiment, when the brightness of the measured reflected light is high (when the reflectance of the projection surface 15 is high), the light output of the lamp 4 is lower than when it is low. Reduce the lamp power. When measuring the brightness of the reflected light, it is desirable to set the light output of the lamp 4 that is predetermined for the reflected light measurement.

  Next, the operation of the projector will be described with reference to the flowchart of FIG. Steps S601, S602, and S604 to S609 in FIG. 6 are the same as steps S201, S202, and S204 to S209 in the first embodiment (FIG. 2), respectively, and thus description thereof is omitted.

  The controller 11 that has proceeded from step S602 to step S610 drives the reflected light photometric sensor 17, and measures the brightness of the reflected light reflected by the projection surface 15 out of the projected light.

  Next, in step S611, the controller 11 reads the use lens brightness information from the memory (memory 14) of the use projection lens (projection lens 13). Then, a target lamp power for setting the projection brightness to the target brightness is calculated using the used optical system brightness information and the brightness of the reflected light measured in step S610. And it progresses to the process after step S604.

  According to this embodiment, an appropriate projection brightness can be maintained regardless of the brightness performance of the used projection lens and the reflectance of the projection surface 15. In addition, when a bright projection lens is mounted or when the projection is performed on the projection surface 15 having a high reflectance, wasteful power consumption and shortening of the life of the lamp 4 can be suppressed.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

  An interchangeable lens type image projection apparatus capable of projecting an image with good brightness can be provided.

4 Lamp 3 Ballast power supply 7 Image forming panel 9, 13 Projection lens 11 Controller 12, 14 Memory 20, 30, 40 Projector

Claims (5)

An image projection device that modulates light from a light source with an image forming element and displays an image by projecting it onto a projection surface through a replaceable projection optical system,
Having control means for controlling the light output of the light source;
The control means includes
The projection optics mounted on the apparatus from storage means for storing optical system brightness information, which is information relating to the brightness of each of the plurality of projection optical systems exchangeable with the apparatus, individually or collectively Read the used optical system brightness information which is the optical system brightness information corresponding to the system,
Using the use optical system brightness information, the brightness of the projection light projected from the projection optical system onto the projection surface becomes a target brightness set in common for the plurality of projection optical systems. As described above, the light output is controlled as described above. Environmental brightness measuring means for measuring environmental brightness which is the ambient brightness of the device;
The control means uses the environmental brightness measured by the environmental brightness measurement means and the optical system brightness information to adjust the light output so that the brightness of the projection light becomes the target brightness. The image projection apparatus according to claim 1, wherein the image projection apparatus is controlled. Reflected light measuring means for measuring the brightness of the reflected light projected from the projection optical system and reflected by the projection surface;
The control means uses the brightness of the reflected light measured by the reflected light measuring means and the information on the brightness of the used optical system so that the brightness of the projection light becomes the target brightness. The image projection apparatus according to claim 1, wherein the image projection apparatus is controlled. A method of controlling an image projection apparatus that displays an image by modulating light from a light source with an image forming element and projecting the light onto a projection surface through a replaceable projection optical system,
Preparing optical system brightness information, which is information about the brightness of each of the plurality of projection optical systems that can be exchanged for the image projection apparatus;
The brightness of the projection light projected from the projection optical system onto the projection surface using the use optical system brightness information corresponding to the projection optical system mounted on the image projection apparatus among the optical system brightness information. Controlling the light output of the light source so as to achieve a target brightness set in common for the plurality of projection optical systems. An operation including the following steps is executed on a computer provided in an image projection apparatus that displays an image by modulating light from a light source by an image forming element and projecting it onto a projection surface through a replaceable projection optical system. A control program as a computer program
From the storage means that stores optical system brightness information, which is information regarding the brightness of each of the plurality of projection optical systems that can be exchanged for the image projection apparatus, individually or collectively, the storage unit mounted on the apparatus Reading use optical system brightness information which is the optical system brightness information corresponding to the projection optical system;
Using the used optical system brightness information, the brightness of the projection light projected from the projection optical system onto the projection surface becomes a target brightness set in common for the plurality of projection optical systems. And a step of controlling the light output of the light source as described above.