JP5471194B2 - projector - Google Patents

Description

  The present invention relates to a projector that projects a light beam formed by a liquid crystal panel or the like on a screen as an image.

  As an optical device such as a video camera, a rear focus zoom lens including a moving lens group, an automatic focusing means for detecting a focusing state of the rear focus zoom lens, and an automatic for driving the moving lens group to perform automatic focusing. Some include a focusing control means (see Patent Document 1). In this optical apparatus, when detecting means such as temperature and humidity is provided in the rear focus zoom lens and the operation of the automatic focusing means is stopped, the temperature, humidity and the like are changed based on the output of the detecting means. The position shift of the image plane of the rear focus zoom lens is corrected.

Japanese Patent Laid-Open No. 9-211312

  However, in the case of a projector, a heat distribution is often formed in the case, and not only the temperature change of the projection lens itself, but also the temperature change around the projection lens, the space between the imaging surface and the liquid crystal panel. Misalignment often occurs. That is, when the focus state of the projection lens is adjusted based on only changes in the temperature, humidity, etc. of the projection lens itself as in the above-mentioned Patent Document 1, there is a possibility that the focus shift cannot be sufficiently suppressed.

  SUMMARY An advantage of some aspects of the invention is to provide a projector that can compensate for a focus shift caused by a change in the surrounding environment of the projection lens.

  In order to solve the above problems, a projector according to the present invention includes a display unit that displays an image, a projection lens that projects an image displayed on the display unit, a coupling unit that couples the display unit and the projection lens, and a coupling And a lens moving unit that moves at least a part of the projection lens based on the detection result of the detecting unit.

  According to the projector, since the lens moving unit moves at least a part of the projection lens based on the detection result of the detection unit that detects information on the state of the connecting unit, Even when the distance from the display unit changes, the back focus position of the projection lens can be adjusted to offset this, and the image-forming position on the screen side can be maintained. A projector capable of projecting on a screen can be provided.

  According to a specific aspect or aspect of the invention, in the projector, the detection unit includes a first sensor that is attached to the connection unit and detects the temperature of the connection unit. In this case, it is possible to change the back focus position of the projection lens so as to cancel out the amount of expansion and contraction of the connecting portion due to the temperature change, and provide a projector that can project a good image regardless of the temperature change of the connecting portion. be able to.

  According to another aspect of the present invention, the lens moving unit calculates a movement amount of the whole or a part of the projection lens based on the detection result of the detection unit, and the projection lens according to the calculation result of the calculation unit A lens driving device for moving all or part of the lens. In this case, the back focus position can be appropriately changed by driving the projection lens according to the temperature of the connecting portion.

  According to still another aspect of the invention, the detection unit includes a second sensor that is attached to the projection lens and detects the temperature of the projection lens. In this case, the temperature state of the projection lens itself can be monitored.

  According to still another aspect of the invention, the calculation unit calculates the movement amount of the whole or a part of the projection lens based on the detection results of the first and second sensors. In this case, the focus state of the projection lens can be adjusted in consideration of the temperature change of the projection lens itself, and a projector capable of projecting a better image can be provided.

  According to still another aspect of the present invention, an illumination optical system that emits illumination light for illuminating the display unit is further provided. In this case, the image displayed on the display unit can be projected onto a screen or the like with sufficient luminance.

  According to still another aspect of the present invention, the display unit is a light modulation device that modulates illumination light from the illumination optical system. In this case, various images displayed on the light modulation device can be projected on a screen or the like.

  According to still another aspect of the present invention, the illumination optical system can change the emission intensity of the illumination light, and the detection unit maintains the emission intensity of the illumination light from the illumination optical system at a predetermined level or higher. 2nd operation mode in which it detects that a connection part is a comparatively high-temperature state as information regarding the condition of a connection part, and the emission intensity | strength of the illumination light from an illuminating device changes to less than predetermined when it is 1 operation mode If it is, it detects that a connection part is a comparatively low temperature state as information regarding the condition of a connection part. In this case, the back focus position of the projection lens can be adjusted so as to conform to the first and second operation modes related to the emission intensity of the illumination light from the illumination optical system.

1 is a diagram conceptually illustrating a projector according to a first embodiment. It is a side view explaining the principal part of the optical system of the projector shown in FIG. 2 is a flowchart for explaining the operation of the projector shown in FIG. It is a side view explaining the principal part of the projector which concerns on 2nd Embodiment. It is a flowchart explaining operation | movement of the projector which concerns on 2nd Embodiment. It is a figure which shows notionally the projector which concerns on 3rd Embodiment. 7 is a flowchart for explaining the operation of the projector shown in FIG. 6.

[First Embodiment]
The projector according to the first embodiment of the present invention will be described below with reference to FIG. The illustrated projector 100 includes an optical system portion 10 for image formation and projection, and a control device 90 that controls the operation of the optical system portion 10.

[1. Projector optics)
The optical system portion 10 shown in FIG. 1 includes an illumination optical system 20 that emits illumination light, a color separation light guide optical system 40 that separates illumination light from the illumination optical system 20 into three color lights of blue, green, and red, and a color A light modulating unit 50 that modulates the three color lights emitted from the separation light guide optical system 40 according to image information, a light combining optical system 60 that combines the image light of each color emitted from the light modulating unit 50, and light combining A projection optical system that projects the image light combined by the optical system 60 onto a screen (not shown). Among these, the light modulation unit 50 and the light combining optical system 60 constitute a display device 81 for modulating illumination light to form an image. The parts from the illumination optical system 20 to the light combining optical system 60 are accommodated in the optical component casing 11.

■ Claim 6
The illumination optical system 20 includes a light source device 21, a concave lens 22, first and second lens arrays 24 and 25, a polarization conversion device 26, a superimposing lens 27, and a light control mechanism 31. Among these, the light source device 21 is a light source that emits a light beam for illumination. For example, a discharge-type arc tube 21 a such as a high-pressure mercury lamp and the light beam emitted from the arc tube 21 a are collected and emitted forward. And an ellipsoidal concave mirror 21b. The concave lens 22 has a role of collimating the light beam from the light source device 21, but may be omitted when the concave mirror 21b is a parabolic mirror, for example. The first and second lens arrays 24 and 25 are fly-eye lenses each composed of a plurality of element lenses arranged in a matrix. Among these, the light beam emitted from the light source device 21 is divided into a plurality of partial light beams by the element lenses constituting the first lens array 24. In addition, each partial light beam from the first lens array 24 is emitted at an appropriate divergence angle by the element lenses constituting the second lens array 25. The polarization conversion device 26 is composed of a prism array incorporating a PBS and a wavelength plate, and is a polarization conversion unit that converts the split light beam emitted from the lens array 25 into only linearly polarized light in a specific direction and supplies it to the next stage optical system. is there. The superimposing lens 27 appropriately superimposes the illumination light as linearly polarized light that has passed through the polarization converter 26 as a whole, thereby superimposing illumination on the liquid crystal light valves 50r, 50g, and 50b of the respective colors provided in the illuminated region, that is, the light modulation unit 50. Enable. In other words, the illumination light that has passed through both the lens arrays 24 and 25 and the superimposing lens 27 passes through the color separation light guide optical system 40 described in detail below, and each color liquid crystal panel 51r, provided in the light modulation unit 50. 51g and 51b are uniformly superimposed and illuminated.

  The light control mechanism 31 is disposed inside the illumination optical system 20, for example, between the first and second lens arrays 24 and 25, and is emitted from the illumination optical system 20 by opening and closing the pair of light shielding portions 33 and 34. At least part of the illumination light to be emitted is shielded continuously or stepwise to adjust the amount of illumination light, that is, the emission intensity of the illumination light.

  The color separation light guide optical system 40 includes first and second dichroic mirrors 41a and 41b, reflection mirrors 42a, 42b, and 42c, and three field lenses 43r, 43g, and 43b, and is emitted from the light source device 21. The separated illumination light is separated into three colors of red (R), green (G), and blue (B), and the separated color lights are guided to the liquid crystal light valves 50r, 50g, and 50b at the subsequent stage. More specifically, first, the first dichroic mirror 41a reflects the R illumination light LR out of the three RGB colors and transmits the G and B illumination lights LG and LB. Further, the second dichroic mirror 41b reflects the G illumination light LG of the two colors GB and transmits the B illumination light LB. That is, the red light LR reflected by the first dichroic mirror 41a is guided to the first optical path OP1 with the field lens 43r, is transmitted through the first dichroic mirror 41a, and is reflected by the second dichroic mirror 41b. The green light LG is guided to the second optical path OP2 having the field lens 43g, and the blue light LB having passed through the second dichroic mirror 41b is guided to the third optical path OP3 having the field lens 43b. The field lenses 43r, 43g, and 43b for the respective colors are adjusted so that the partial light beams emitted from the second lens array 25 have an appropriate incident angle on the irradiated areas of the liquid crystal light valves 50r, 50g, and 50b. doing. The pair of relay lenses 44a and 44b is disposed on a third optical path OP3 that is relatively longer than the first optical path OP1 and the second optical path OP2, and an image formed immediately before the first relay lens 44a on the incident side. By transmitting the light to the field lens 43b on the exit side almost as it is, the light use efficiency is prevented from being lowered due to light diffusion or the like.

  The light modulation unit 50 includes three liquid crystal light valves 50r, 50g, and 50b into which illumination lights LR, LG, and LB of three colors are incident, respectively. Each of the liquid crystal light valves 50r, 50g, and 50b is a non-light-emitting light modulator that modulates the spatial distribution of the intensity of incident illumination light.

  Each of the liquid crystal light valves 50r, 50g, 50b includes a liquid crystal panel 51r, 51g, 51b disposed in the center, and an incident side polarizing filter 52r, 52g, 52b disposed on one light incident side so as to sandwich the liquid crystal panel 51r, 51g, 51b. Emission side polarization filters 53r, 53g, and 53b are provided on the other light emission side, respectively. The liquid crystal panels 51r, 51g, and 51b are not shown in the drawings, but a light-transmitting substrate having a transparent electrode or the like, a light-transmitting driving substrate having a pixel electrode or the like, and between the light-transmitting substrate and the driving substrate And a liquid crystal layer hermetically sealed. The color lights LR, LG, LB incident on the liquid crystal light valves 50r, 50g, 50b are in units of pixels in accordance with the drive signals or image signals input as electrical signals to the liquid crystal light valves 50r, 50g, 50b. Intensity modulated.

  The light combining optical system 60 is a cross dichroic prism, has a substantially square shape in plan view in which four right angle prisms are bonded together, and a pair of dichroic mirrors 61 intersecting in an X shape at the interface where the right angle prisms are bonded together. , 62 are formed. Both dichroic mirrors 61 and 62 are formed of dielectric multilayer films having different characteristics. That is, one first dichroic mirror 61 reflects red light LR, and the other first dichroic mirror 62 reflects blue light LB. The light combining optical system 60 reflects the modulated red light LR from the liquid crystal light valve 50r by the first dichroic mirror 61 and emits it in the Z direction by bending the optical path, and modulates green light from the liquid crystal light valve 50g. The light LG is transmitted through the first and second dichroic mirrors 61 and 62 so as to travel straight in the Z direction, and the modulated blue light LB from the liquid crystal light valve 50b is reflected by the second dichroic mirror 62 to bend the optical path. To inject in the Z direction. On the light emitting side of the light combining optical system 60, the color lights LR, LG, and LB are superimposed to perform color combining.

  The projection optical system 70 includes a projection lens 71 that enlarges and projects the color image light combined by the light combining optical system 60, a lens driving device 72 that operates under the control of the control device 90, and adjusts the state of the projection lens 71. Is provided. The projection lens 71 is a zoom lens that projects images on the liquid crystal panels 51r, 51g, 51b onto a screen (not shown) at a desired magnification. Although not shown, the lens driving device 72 includes an actuator, a mechanical mechanism, a sensor, and the like. The lens driving device 72 detects lens information such as the projection magnification and the lens shift amount of the projection lens 71 and outputs the detected lens information to a lens drive control unit 95 described later, and projects based on a control signal from the lens drive control unit 95. The projection magnification, lens shift amount, back-for-focus amount, etc. of the lens 71 can be changed. Note that by changing the lens shift amount, which is the overall movement of the projection lens 71 in the Y direction, image projection in a state with little shape distortion at a position shifted in the + Y direction from the system optical axis SA or the optical axis OA. Is possible. Although details will be described later, by moving a part of the projection lens 71 in the direction of the optical axis OA, the projection magnification can be changed, or the back-for-focus amount can be changed minutely. ing. By the above projection optical system 70, a color moving image or a color still image obtained by synthesizing each color image corresponding to the drive signal or display signal input to each liquid crystal panel 51r, 51g, 51b is projected on the screen at a desired magnification. The

  FIG. 2 is a side view for explaining a method for fixing the light modulation unit 50 and the light combining optical system 60 to the projection optical system 70. The light modulation unit 50 and the light combining optical system 60 are integrated to form a display device 81 and function as a display unit that displays an image.

  The connecting portion 82 for fixing the projection optical system 70 and the display device 81 to each other includes a frame member 82a that supports the projection optical system 70, a holder member 82b that supports the display device 81, a frame member 82a, and a holder member 82b. And an intermediate member 82c interposed therebetween. The frame member 82a, the holder member 82b, and the intermediate member 82c are integrally formed of, for example, an aluminum die cast, a magnesium die cast, or other material having a relatively small linear expansion coefficient. A first temperature sensor 97 that detects the temperature of the connecting portion 82 is attached to the intermediate member 82c as a first sensor. The first temperature sensor 97 is formed of a temperature sensitive element such as a thermistor, for example, and its operation is controlled by a detection circuit 96 provided in the control device 90. Note that the frame member 82a of the connecting portion 82 is fixed to the optical component casing 11 shown in FIG.

  The projection lens 71 of the projection optical system 70 is supported by the frame member 82 a via the lens driving device 72. That is, the lens driving device 72 is fixed to the frame member 82a on the one hand and supported by the frame member 82a, and is fixed to the flange 71f of the projection lens 71 on the other hand to support the projection lens 71. A second temperature sensor 98 that detects the temperature of the projection optical system 70 is attached to the projection lens 71 as a second sensor. The second temperature sensor 98 is formed of a temperature sensitive element such as a thermistor, for example, and its operation is controlled by a detection circuit 96 provided in the control device 90. In addition, the display device 81 side, that is, the optical path upstream side portion of the lens barrel 71a of the projection lens 71 is passed through the opening 85 of the frame member 82a.

  The display device 81 is fixed to the holder member 82b by using an adhesive or the like on the bottom surface 60r of the photosynthetic optical system 60. Here, liquid crystal light valves 50r, 50g, and 50b for the respective colors are fixed to the three incident surfaces 65 that are the side surfaces of the light combining optical system 60 via support members 68r, 68g, and 68b for alignment.

  The lens driving device 72 can appropriately translate the projection lens 71 from the position on the optical axis OA along the CD direction perpendicular to the optical axis OA direction. Thus, the optical axis OA of the projection lens 71 is system-controlled. By the lens shift intentionally shifted with respect to the optical axis SA, the projection direction by the projection lens 71 can be set to an oblique direction inclined by a desired angle with respect to the optical axis OA, for example, in the + Y direction. Further, the lens driving device 72 can individually reciprocate the lens groups 71 a, 71 b, 71 c, etc. in the direction of the optical axis OA via a partial driving mechanism 73 provided in the projection lens 71. The magnification can be adjusted. Further, the lens driving device 72 can finely move the lens groups 71a, 71c and the like in the direction of the optical axis OA via the partial driving mechanism 73, and can project in accordance with environmental conditions such as a positional deviation of the display device 81. The back focus amount of the lens 71 can be adjusted. That is, the lens driving device 72 constitutes a lens moving unit for moving a part of the projection lens 71 based on the temperature detection result of the connecting unit 82 together with a main control unit 99 of the control device 90 described later. Of the projection lens 71, for example, the lens group 71d can be manually finely moved in the direction of the optical axis OA, and is used for manual adjustment of a focus state by the projection lens 71, that is, a screen-like focus state.

  Hereinafter, the first focus compensation function of the lens driving device 72 will be described. First, it is assumed that the connecting portion 82 slightly expands and contracts with a change in temperature, and the position of the liquid crystal light valve 50g and the like with respect to the frame member 82a that supports the projection lens 71 slightly changes with the temperature. . More specifically, when the connection part 82, particularly the periphery of the intermediate member 82c, is at room temperature, the distance from the frame member 82a to the liquid crystal light valve 50g is D0 as shown by the solid line in FIG. Here, assuming that the projection lens 71 is maintained at a normal temperature and its back focus amount is kept at the standard value BF0, the back focus position of the projection lens 71 corresponds to the position of the liquid crystal light valve 50r indicated by the solid line. Thus, focusing on a screen (not shown) is possible. After that, when the periphery of the connecting portion 82 is heated to a high temperature state by the temperature difference ΔT1, the distance from the frame member 82a to the liquid crystal light valve 50g increases from D0 as shown by a two-dot chain line in FIG. The change value D1. Here, it is assumed that the temperature of the projection lens 71 remains unchanged. In this case, the back focus amount of the projection lens 71 is adjusted with respect to the standard value BF0 by appropriately operating the lens driving device 72 to finely move the lens groups 71a, 71c and the like constituting the projection lens 71 in the direction of the optical axis OA. Thus, the corrected back focus amount BF1 = BF0 + ΔD, which is increased by adding the positive difference ΔD = D1−D0, can be obtained. Here, since the difference ΔD is generally proportional to the temperature difference ΔT1, if the temperature coefficient α is used, it can be expressed as ΔD = α · ΔT1. By performing the correction of the back focus amount as described above, the back focus position of the projection lens 71 can be matched with the position of the liquid crystal light valve 50r or the like indicated by a two-dot chain line. On the other hand, when the periphery of the connecting portion 82 is at a temperature lower than the normal temperature by the temperature difference ΔT1, the illustration is omitted, but the distance from the frame member 82a to the liquid crystal light valve 50g is smaller than D0 and the change value D1. It becomes. Here, the lens driving device 72 is operated as appropriate, and the corrected back focus amount BF1 = BF0 + ΔD, which is obtained by adding the negative difference ΔD = D1-D0 to the standard value BF0 and reducing the back focus amount. If so, the back focus position of the projection lens 71 can be matched with the position of the liquid crystal light valve 50r or the like. That is, the images of the liquid crystal light valves 50r, 50g, and 50b can be projected in a focused state on a screen (not shown) regardless of the temperature environment around the connecting portion 82. In the above description, the temperature coefficient α is assumed to be constant. However, if the temperature coefficient α (T) that varies with temperature is used even if the temperature coefficient α varies greatly with temperature, the back focus position can be accurately determined. Temperature compensation becomes possible.

  Hereinafter, the second focus compensation function of the lens driving device 72 will be described. In the above description, it is assumed that the projection lens 71 is kept at room temperature, but the actual temperature of the projection lens 71 changes due to the influence of the environment and the like. When the projection lens 71 is heated during image projection and becomes a relatively high temperature state, for example, the back focus amount of the projection lens 71 decreases from BF0 to BF1 ′, and the back focus position shifts to the downstream side of the optical path by the difference ΔB. It will be a thing. That is, the temperature coefficient β of increase / decrease in the focal length of the projection lens 71 is a negative value in this example, and the back focus amount tends to be shortened by the difference ΔB = β · ΔT2 with the rising temperature difference ΔT2. . Here, it is assumed that the distance from the frame member 82a to the liquid crystal light valve 50g is maintained at the standard value D0 when the connecting portion 82 is at room temperature. In this case, the back focus amount BF1 ′ of the projection lens 71 is set to a positive difference ΔB by appropriately operating the lens driving device 72 and finely moving the lens groups 71a, 71c and the like constituting the projection lens 71 in the optical axis OA direction. '= -ΔB = -β · ΔT2 can be increased and returned to the standard value BF0. Thereby, the back focus position of the projection lens 71 can be made to coincide with the position of the liquid crystal light valve 50r indicated by the solid line. Conversely, when the projection lens 71 is in a relatively low temperature state, although not shown, the back focus amount of the projection lens 71 increases from BF0, and the back focus position is shifted to the upstream side of the optical path. Here, if the back drive amount of the projection lens 71 is decreased by a negative difference ΔB ′ = − β · ΔT2 and returned to the standard value BF0 by appropriately operating the lens driving device 72, the back focus of the projection lens 71 is restored. The position can be matched with the position of the liquid crystal light valve 50r or the like. That is, regardless of the temperature of the projection lens 71, the images of the liquid crystal light valves 50r, 50g, and 50b can be projected in a focused state on a screen (not shown). In the above, the temperature coefficient β is considered to be constant. However, if the temperature coefficient β (T) that changes with temperature is used even if the temperature coefficient β changes greatly with temperature, the accurate temperature of the back focus position is used. Compensation is possible.

  In the above, it is assumed that the projection lens 71 is in a normal temperature state or the connecting portion 82 is in a normal temperature state. However, both the projection lens 71 and the connecting portion 82 may be deviated from the normal temperature state. In this case, the first focus compensation function and the second focus compensation function are performed collectively. That is, the lens groups 71a, 71c and the like constituting the projection lens 71 are finely moved in the direction of the optical axis OA as appropriate, and the back focus amount of the projection lens 71 is offset by the compensation amount obtained by adding ΔD and ΔB ′. Focus compensation is possible in the system including the projection optical system 70 and the display device 81.

  The lens to be moved during the focus compensation is not limited to the lens groups 71a and 71c, but may be a correction lens (not shown) specially provided in the projection lens 71.

[2. Projector control system)
As shown in FIG. 1, the control device 90 drives the liquid crystal light valves 50 r, 50 g, and 50 b based on the image processing unit 91 to which an external image signal such as a video signal is input and the output of the image processing unit 91. A panel driving unit 92, a dimming mechanism driving unit 93 that drives the dimming mechanism 31 based on the output of the image processing unit 91, and a lighting driving unit 94 that supplies power to the light source device 21 to adjust the lighting state of the arc tube 21a. And a lens drive control unit 95 for adjusting the image formation state by the projection optical system 70 and a main control unit 99 for comprehensively controlling the operations of these circuit portions 91, 94, 95 and the like. The control device 90 operates by receiving power from the power supply device 101.

  In the control device 90, the image processing unit 91 performs color correction, distortion correction, or the like on the input external image signal, and displays character information or the like instead of or superimposing the image corresponding to the external image signal. can do.

  The panel drive unit 92 generates a drive signal for adjusting the state of each of the liquid crystal light valves 50r, 50g, and 50b based on the image signal after image processing output from the image processing unit 91. Accordingly, an image as a transmittance distribution can be formed in the liquid crystal light valves 50r, 50g, and 50b corresponding to the image signal input from the image processing unit 91.

  The dimming mechanism driving unit 93 controls the open / closed state of the dimming mechanism 31. The dimming mechanism driving unit 93 moves the dimming mechanism 31 between the closed state in which the light shielding units 33 and 34 block most of the optical path and the open state in which the light shielding units 33 and 34 open the optical path. A continuous or stepwise opening / closing operation is performed.

  The lighting drive unit 94 adjusts the light emission state of the arc tube 21a by adjusting the voltage and current amplitude and period supplied to the arc tube 21a.

  The lens drive control unit 95 appropriately operates the lens drive device 72 by outputting a control signal to the lens drive device 72, and sets the projection magnification of the projection lens 71, the lens shift amount, the back for focus amount, and the like as desired. Can be in a state. The lens drive control unit 95 receives detection signals from a zoom position sensor, a shift sensor, and the like built in the lens drive device 72, and monitors lens information such as the projection magnification of the projection lens 71 and the lens shift amount. doing.

  The main control unit 99 includes a microcomputer, a memory, and the like, and operates based on a program appropriately prepared for controlling the image processing unit 91, the lighting drive unit 94, the lens drive control unit 95, and the like. Thereby, the operation state of the projector 100 is appropriately maintained. In the present embodiment, the main control unit 99 monitors the detection output of the first temperature sensor 97 via the detection circuit 96, and uses the projection lens 71 as a calculation unit based on the detection result of the first temperature sensor 97. A first movement amount that is an amount by which some of the constituent lens groups 71a and 71c are moved for temperature compensation is calculated. The amount of movement need not directly represent the distance, but may be any amount that corresponds to the driving amount of the lens driving device 72. The main control unit 99 also monitors the detection output of the second temperature sensor 98 via the detection circuit 96, and as a calculation unit, a part of the projection lens 71 that constitutes the projection lens 71 based on the detection result of the second temperature sensor 98. A second movement amount that is an amount by which the lens groups 71a and 71c are moved for temperature compensation is calculated. The main control unit 99 adds the first movement amount and the second movement amount, prepares a control signal for changing the back focus amount of the projection lens 71 by the addition value ΔD + ΔB ′, and outputs this control signal. This is output to the lens drive control unit 95. The main control unit 99 stores a conversion table and a conversion formula necessary for calculating the above differences ΔD and ΔB ′ in the nonvolatile memory portion.

[3. Focus compensation operation)
Hereinafter, the focus compensation operation in the projector 100 of the present embodiment will be described with reference to the flowchart of FIG.

  First, the projector 100 performs image signal display processing (step S10). That is, when a video signal is input to the control device 90 via the image signal input terminal, the main control unit 99 operates the image processing unit 91 to cause the liquid crystal light valves 50r, 50g, and 50b to respond to the video signal. Light modulation is performed.

  Next, the main control unit 99 detects the temperature difference ΔT1 from the normal temperature of the intermediate member 82c based on the detection result of the first temperature sensor 97 as a detection unit (step S11).

  Next, the main control unit 99 calculates the above-described difference ΔD as the correction amount of the back focus amount of the projection lens 71 from the temperature difference ΔT1 obtained in step S11 (step S12).

  Next, the main control unit 99 detects the temperature difference ΔT2 from the normal temperature of the projection lens 71 based on the detection result of the second temperature sensor 98 which is a detection unit (step S13).

  Next, the main control unit 99 calculates the above-described difference ΔB ′ as the correction amount of the back focus amount of the projection lens 71 from the temperature difference ΔT2 obtained in step S13 (step S14).

  Next, the main control unit 99 calculates the addition value ΔD + ΔB ′ of the two differences described above as the total correction amount of the back focus amount of the projection lens 71 (step S15).

  Next, the main control unit 99 outputs the control signal corresponding to the amount of movement that gives the added value ΔD + ΔB ′ to the lens drive control unit 95, thereby appropriately operating the lens drive device 72 to display the projection optical system 70 and the display. Focus compensation is performed in the system including the device 81 (step S17).

  The main control unit 99 returns to step S10 after the operation of step S17 (N in step S18) until the end of the projection operation is instructed by turning off the power (Y in step S18).

  In the above description, the difference ΔB ′, which is a change in the back focus amount of the projection lens 71 due to the temperature change of the projection lens 71, is relatively large. However, when the difference ΔB ′ is small compared to the difference ΔD, The control unit 99 can operate based only on the detection result of the first temperature sensor 97. In this case, the second temperature sensor 98 is not necessary, and the main control unit 99 calculates only the difference ΔD as the total correction amount of the back focus amount of the projection lens 71, and sends a control signal corresponding to the movement amount of the difference ΔD to the lens. By outputting to the drive control unit 95, the lens driving device 72 is appropriately operated to perform focus compensation.

  According to the projector 100 described above, a part of the projection lens 71 is based on the detection result of the first temperature sensor 97 in which the main control unit 99 as the lens moving unit and the lens driving device 72 detect the temperature information of the connecting unit 82. Therefore, even when the interval between the projection lens 71 and the display device 81 changes due to the temperature change of the connecting portion 82, the back focus position of the projection lens 71 can be adjusted so as to cancel out the change. The projector 100 that can project a good image regardless of the change can be provided.

[Second Embodiment]
Hereinafter, the configuration of the optical system of the projector according to the second embodiment will be described. The projector according to the second embodiment is a modification of the projector 100 according to the first embodiment, and portions that are not particularly described are the same as those in the first embodiment.

  FIG. 4 corresponds to FIG. 2 and is a side view of a main part of the projector 100 according to the second embodiment. In this case, the lens driving device 72 can slightly change the back-for-focus position by moving the entire projection lens 71 in the direction of the optical axis OA.

  Hereinafter, the first focus compensation function of the lens driving device 72 will be described. When the periphery of the connecting portion 82, particularly the intermediate member 82c, is at room temperature, the distance from the frame member 82a to the liquid crystal light valve 50g is D0 as shown by the solid line in FIG. Here, if the back focus amount BF0 of the projection lens 71 is maintained at a standard value, the back focus position of the projection lens 71 corresponds to the position of the liquid crystal light valve 50r and the like indicated by a solid line. Thus, focused imaging can be performed on a screen (not shown). Thereafter, when the periphery of the connecting portion 82 is heated to a high temperature state by the temperature difference ΔT1, the distance from the frame member 82a to the liquid crystal light valve 50g extends to D1, as indicated by a two-dot chain line in FIG. . Here, if the back focus amount BF0 of the projection lens 71 is maintained at the standard value, the lens driving device 72 is appropriately operated to make the projection lens 71 as a whole positive difference ΔD = D1−D0 in the −Z direction. By moving by = α · ΔT1, the back focus position of the projection lens 71 can be matched with the position of the liquid crystal light valve 50r or the like indicated by a two-dot chain line. On the contrary, when the periphery of the connecting portion 82 becomes a temperature lower than the normal temperature by the temperature difference ΔT1, the distance from the frame member 82a to the liquid crystal light valve 50g is shorter than D0 although illustration is omitted. Here, if the back focus amount BF0 of the projection lens 71 is maintained at the standard value, the lens driving device 72 is appropriately operated to cause the entire projection lens 71 to have a negative difference ΔD = D1−D0 in the −Z direction. By appropriately moving = α · ΔT1, that is, in the + Z direction, the back focus position of the projection lens 71 can be matched with the position of the liquid crystal light valve 50r or the like. That is, the images of the liquid crystal light valves 50r, 50g, and 50b can be projected in a focused state on a screen (not shown) regardless of the temperature environment around the connecting portion 82.

  Hereinafter, the second focus compensation function of the lens driving device 72 will be described. In the following, it is assumed that the projection lens 71 changes from the normal temperature state and the back focus amount BF0 changes. When the projection lens 71 is heated during image projection and becomes a high temperature state by ΔT2, the back focus amount of the projection lens 71 is decreased from BF0 to BF2, and the back focus position is the difference ΔB = β · ΔT2 on the downstream side of the optical path. It will be shifted. Here, if the distance from the frame member 82a to the liquid crystal light valve 50g is maintained at the standard value D0, the lens driving device 72 is appropriately operated to make the entire projection lens 71 have a negative difference ΔB ′ in the + Z direction. By moving by = −ΔB, the back focus position of the projection lens 71 can be made to coincide with the position of the liquid crystal light valve 50r indicated by the solid line. On the contrary, when the projection lens 71 is in a state of lower temperature than the normal temperature by the temperature difference ΔT2, the back focus amount of the projection lens 71 is increased from BF0, and the back focus position is shifted to the upstream side of the optical path. It will be a thing. Here, if the distance from the frame member 82a to the liquid crystal light valve 50g is maintained at the standard value D0, the lens driving device 72 is appropriately operated to make the entire projection lens 71 positive difference ΔB ′ in the + Z direction. By moving by = −ΔB, the back focus position of the projection lens 71 can be made to coincide with the position of the liquid crystal light valve 50r indicated by the solid line. That is, regardless of the temperature of the projection lens 71, the images of the liquid crystal light valves 50r, 50g, and 50b can be projected in a focused state on a screen (not shown).

  FIG. 5 is a flowchart for explaining the operation of the projector 100 according to the second embodiment. In this case, the main control unit 99 calculates the above-described difference ΔD as the movement amount of the entire projection lens 71 necessary for focus compensation from the temperature difference ΔT1 obtained in step S11 (step S112). Further, the main control unit 99 calculates the above-described difference ΔB ′ as the movement amount of the entire projection lens 71 necessary for focus compensation from the temperature difference ΔT2 obtained in step S13 (step S114). In step S115, the main control unit 99 calculates the added value ΔD + ΔB ′ of the two differences as the total moving amount of the projection lens 71, and in step S17, the control corresponding to the moving amount of the added value ΔD + ΔB ′. The signal is output to the lens drive control unit 95, and the lens drive device 72 causes the system including the projection optical system 70 and the display device 81 to perform focus compensation.

  According to the projector 100 described above, the main control unit 99 as the lens moving unit and the lens driving device 72 move the entire projection lens 71 based on the detection result of the first temperature sensor 97 that detects the temperature information of the connecting unit 82. Therefore, even when the distance between the projection lens 71 and the display device 81 is changed due to the temperature change of the connecting portion 82, the back focus position of the projection lens 71 can be adjusted so as to cancel out the change, and the environment changes. Regardless, it is possible to provide the projector 100 that can project a good image.

[Third Embodiment]
Hereinafter, the configuration of the optical system of the projector according to the third embodiment will be described. The projector according to the third embodiment is a modification of the projector 100 according to the first embodiment, and portions that are not particularly described are the same as those in the first embodiment.

  FIG. 6 corresponds to FIG. 1 and illustrates the structure of the projector 200 according to the third embodiment. In this case, without providing the temperature sensors 98 and 98 as shown in FIG. 1, the main control unit 99 detects the open / closed state of the pair of light shielding units 33 and 34 constituting the dimming mechanism 31. That is, the main control unit 99 monitors the open / closed state of the light shielding units 33 and 34 as the operation state of the light control mechanism driving unit 93 via the image processing unit 91.

  The projector 200 can operate in a first operation mode in which the light control mechanism 31 is in an open state and a second operation mode in which the amount of light blocked by the light control mechanism 31 is increased or decreased according to the display image. . The second operation mode is an operation mode for increasing dynamic contrast. When the projector 200 operates in the second operation mode, the dimming mechanism 31 opens and closes according to the projection image under the control of the dimming mechanism driving unit 93. That is, in the second operation mode, the amount of light shielding is increased or decreased according to the display image, so that the contrast of the moving image can be improved. The user can set, for example, whether the dynamic contrast priority second operation mode or the luminance priority first operation mode is selected, and the main control unit 99 can select the operation mode. Remembered.

  FIG. 7 is a flowchart for explaining the operation of the projector 200 according to the third embodiment. In this case, the main control unit 99 determines whether or not the projector 200 is set to the high brightness operation mode (step S21). When the main control unit 99 determines that the second operation mode with priority on dynamic contrast is not selected and the first operation mode with priority on luminance is selected, the main control unit 99 sets the correction amount for the back focus amount of the projection lens 71. The difference ΔD is calculated (step S22). In this case, the difference ΔD corresponds to the amount of expansion in the optical axis OA direction of the connecting portion 82 predicted by the operation in the first operation mode. The main control unit 99 outputs a control signal corresponding to the movement amount that cancels out the difference ΔD to the lens drive control unit 95, and causes a part of the projection lens 71 to be finely moved to perform focus compensation (step S17). When the main control unit 99 determines that the second operation mode is selected, it is assumed that the extension amount of the coupling unit 82 in the optical axis OA direction can be almost ignored, and the processing in steps S22 and S17 is omitted. .

  In the above, focus compensation in the first operation mode with high luminance is achieved not only by slightly moving a part of the projection lens 71 but also by slightly moving the entire projection lens 71.

  In the above processing, the temperature change of the projection lens 71 itself is ignored. However, the back focus amount of the projection lens 71 can be increased or decreased in consideration of the temperature change of the projection lens 71.

  In the projector 200 according to the third embodiment described above, the main control unit 99 serves as a detection unit in the first operation mode in which the illumination intensity of the illumination light is maintained at a predetermined level or higher. Since it is determined or detected that it is in a high temperature state, and it is the second operation mode in which the emission intensity of the illumination light changes below a predetermined value, it is determined or detected that the connecting portion 82 is in a relatively low temperature state. The back focus position of the projection lens 71 can be adjusted so as to conform to the first and second operation modes.

  In addition, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it can be implemented in a various aspect, For example, the following deformation | transformation is also possible.

  That is, in the above embodiment, it is assumed that the projectors 100 and 200 are not the autofocus type. However, if the projectors 100 and 200 are the autofocus type, the lens driving device 72 causes the projection lens 71 to perform automatic focus adjustment. be able to. In this case as well, when the autofocus function is stopped, the focus state of the projection lens 71 changes depending on the environmental temperature. Therefore, by executing the operations shown in FIGS. Can project.

  In the above embodiment, the back focus position is adjusted based on the temperature change around the projection lens 71. However, the back focus position can be adjusted in consideration of the humidity change.

  Moreover, in the said embodiment, although the high pressure mercury lamp is used as the light emission tube 21a of the light source device 21 provided in the illumination optical system 20, various light sources, such as a metal halide lamp, can be used as the light emission tube 21a.

  In the above embodiment, a pair of lens arrays 24 and 25 are used to divide the light from the light source device 21 into a plurality of partial light beams. However, the present invention is applied to a projector that does not use such a lens array. Is also applicable. Furthermore, the lens arrays 24 and 25 can be replaced with rod integrators.

  In the first embodiment, the polarization conversion device 26 that converts the light from the light source device 21 or the like into polarized light in a specific direction is used. However, the present invention can also be applied to a projector that does not use such a polarization conversion device 26. It is.

  In the above embodiment, an example in which the present invention is applied to a projector including transmissive liquid crystal light valves 50r, 50g, and 50b has been described. However, the present invention is also applied to a projector including a reflective liquid crystal light valve. It is possible. Here, “transmission type” means that a liquid crystal light valve including a liquid crystal panel transmits light, and “reflection type” means that the liquid crystal light valve reflects light. It means that there is.

  As a projector, there are a front projection type projector that projects an image from the direction of observing the projection surface, and a rear projection type projector that projects an image from the side opposite to the direction of observing the projection surface. The configurations of the projectors 100 and 200 shown in FIG.

  In the above embodiment, only the examples of the projectors 100 and 200 using the three liquid crystal light valves 50r, 50g, and 50b have been described. However, the present invention may include four or more projectors using one or two liquid crystal light valves. It can also be applied to projectors using liquid crystal light valves. When a projector is configured with a single liquid crystal light valve, this liquid crystal light valve serves as a display unit.

  In the projectors 100 and 200 according to the above-described embodiments, the light modulation of each color is performed using the color separation light guide optical system 40, the liquid crystal light valves 50r, 50g, 50b, and the like. Color light modulation and synthesis by using a combination of an illuminated color wheel and a device (light valve as a light modulator) that is composed of pixels of a micromirror and is irradiated with light transmitted through the color wheel Can also be done.

  As a projector, there is an apparatus (OHP) of a type that illuminates a sheet-like original and enlarges and projects an enlarged image of the original with a projection lens, but the present invention is also applicable to this type of projector. At this time, the document support table serves as the display unit, and the detection unit detects information such as the temperature of the connecting unit interposed between the support table and the projection lens.

  DESCRIPTION OF SYMBOLS 10 ... Optical system part, 11 ... Optical component housing, 20 ... Illumination optical system, 21 ... Light source device, 22 ... Concave lens, 24, 25 ... Lens array, 26 ... Polarization conversion device, 27 ... Superimposing lens, 31 ... Tone 40: Color separation light guide optical system, 41a, 41b ... Dichroic mirror, 42a, 42b, 42c ... Reflection mirror, 43r, 43g, 43b ... Field lens, 50 ... Light modulation unit, 50r, 50g, 50b ... Liquid crystal Light valve, 51r, 51g, 51b ... Liquid crystal panel, 52r, 52g, 52b ... Incident side polarizing filter, 53r, 53g, 53b ... Emission side polarizing filter, 60 ... Photosynthesis optical system, 61, 62 ... Dichroic mirror, 70 ... Projection Optical system 71 ... Projection lens 71a, 71b, 71c, 71d ... Lens group 72 ... , A partial drive mechanism, 81 a display device, 82 a connecting portion, 82 a a frame member, 82 b a holder member, 82 c an intermediate member, 90 a control device, 91 an image processing unit, and 92 a panel drive. 93: Dimming mechanism drive unit, 94 ... Lighting drive unit, 95 ... Lens drive control unit, 98, 98 ... Temperature sensor, 99 ... Main control unit, 100, 200 ... Projector, 101 ... Power supply device, LB ... Blue Light, LG ... Green light, LR ... Red light, OA ... Optical axis, OP1, OP2, OP3 ... Optical path

Claims (6)

A display for displaying an image;
A projection lens that projects the image displayed on the display unit;
A connecting part for connecting the display part and the projection lens;
A detecting unit for detecting information on the status of the connecting unit;
A lens moving unit that moves at least a part of the projection lens based on the detection result of the detection unit;
An illumination optical system that emits illumination light for illuminating the display unit;
With
The illumination optical system can change the emission intensity of illumination light,
The detection unit is in a first operation mode in which the emission intensity of illumination light from the illumination optical system is maintained at a predetermined level or higher, or the emission intensity of illumination light from the illumination device changes to less than the predetermined level. Detect whether the operation mode is 2,
When the detection unit detects the first operation mode, the lens moving unit moves at least a part of the projection lens, and the detection unit detects the second operation mode. Furthermore, the lens moving unit does not move the projection lens .   The projector according to claim 1, wherein the detection unit includes a first sensor that is attached to the connection unit and detects a temperature of the connection unit.   The lens moving unit calculates a movement amount of the whole or a part of the projection lens based on the detection result of the detection unit, and the whole or a part of the projection lens according to the calculation result of the calculation unit The projector according to claim 1, further comprising a lens driving device that moves the lens.   The projector according to any one of claims 1 to 3, wherein the detection unit includes a second sensor that is attached to the projection lens and detects a temperature of the projection lens.   The projector according to claim 4, wherein the calculation unit calculates a movement amount of the whole or a part of the projection lens based on detection results of the first and second sensors. The projector according to any one of claims 1 to 5 , wherein the display unit is a light modulation device that modulates illumination light from the illumination optical system.

Images