JP2017173477A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that when removing dust, as dust removal is actuated without confirming the presence or quantity of dust, or as dust removal is actuated manually only when a user feels upon visual confirmation of a projected image that dust obstructs the view, a large amount of energy is consumed for the effect obtained or video quality can hardly be maintained constant depending on an installation environment or a user.SOLUTION: Provided is a projector including a single or a plurality of display elements, the projector also including a first optical path leading from the display elements to a projection lens and a second optical path for efficiently condensing and forming an image of leakage light therefrom, and also arranging in the second optical path an imaging element and a movable lens for focusing for forming an image on the imaging element surface. By adjusting the movable lens for focusing in the second optical path, the display element in the first optical path and an adjacent optical component and the lens surface are brought into focus, whereby states of dust sticking to these are imaged.SELECTED DRAWING: Figure 2

Description

  The present invention automatically detects dust adhering to the display element, optical components in the vicinity thereof, and the surface of the optical lens, and alerts the user or automatically if the dust exceeds a certain size and quantity. The present invention relates to a projector for removing dust.

  Compared to a self-luminous display device such as a display, a projector is a device that optically enlarges an image projected on a display element and projects it on a screen. For this reason, if dust adheres to the interior of the device, particularly the surface of the display element, or the surface of an optical component such as a lens or mirror that is disposed adjacently, it will also appear in the projected image. Depending on the quantity and the place where it is attached, the video quality will be significantly degraded.

  In order to eliminate the above-described adverse effects, a proposal as in Patent Document 1 has been made. In Patent Document 1, in a liquid crystal projector, a vibration element is attached to a liquid crystal panel which is a display element and a polarizing plate, and when dust adheres to the liquid crystal projector, the dust is shaken off by driving them, and by blowing air. An invention has been disclosed to the effect of preventing reattachment by blowing off the fallen dust.

JP 2004-219852 A

  However, the technique disclosed in the above-mentioned Patent Document 1 automatically removes dust without confirming the presence or absence, or when the user visually observes the projected image and feels that the dust is obstructive Only the manual removal operation was performed.

  For this reason, when the check is performed without confirming the presence or absence of dust, the detection interval may be too long in a dusty environment, and the removal effect may not be expected. Conversely, in an environment where there is little dust, the dust removal operation will be performed more than necessary, leading to failure or waste of power consumption. In addition, when the dust removal is manually operated, the operation depends on the subjectivity of the user who is viewing the projected image, so it is difficult to maintain the original image quality regardless of the ground environment or the user.

  For these reasons, the object of the present invention is to automatically detect the presence or absence of dust adhering to the surface of an optical component such as a display element, a lens and a mirror arranged adjacent to each other, and the state of dust adhesion. Therefore, it is an object of the present invention to provide a projector that removes dust only when the image quality is significant and maintains a constant image quality regardless of the user or installation environment.

In order to achieve the above object, a projector according to the present invention provides:
From the image data obtained by providing a dedicated optical path for monitoring dust on the surface of the display element and adjacent optical parts such as lenses and mirrors, and using an image sensor It is characterized in that the presence / absence and amount of dust is calculated, dust removal is performed only when the size exceeds a certain size and quantity, or the user is alerted.

  According to the projector of the present invention, the dust removal operation or the alert display is performed based on the result of automatically determining the presence or absence of dust attached to the display element and the optical components such as the adjacent lens and mirror. Do. Therefore, in an environment where there is little dust, it is not necessary to perform an unnecessary dust removal operation or a warning display, which contributes to energy saving. Further, since the dust adhesion state can be maintained at a certain level regardless of the installation environment and the user, a high-quality projection image can be provided.

Embodiment (outline) Embodiment (Optical) Block Diagram Block Diagram Flow chart of the first embodiment Flowchart of the second embodiment Warning screen Test image for dust detection

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a top view (a) of a projector according to an embodiment of the present invention, and side views (b), (c), and (d) viewed from the direction of an arrow in the drawing.

  In FIG. 1A, 101 is a projector body, and 102 is a projection lens. Reference numeral 103 is a power button, 104 is a menu button for calling a setting screen, 105 is a button for selecting a video signal input destination, and 106 is a button for determining on the menu screen. Reference numerals 107 to 110 are buttons for menu selection.

  In FIG. 1B, 111 is a digital video signal input terminal, and 112 is an analog video signal input terminal. Reference numeral 113 denotes a high-speed data communication terminal for connecting to an image data input device such as a digital camera or a storage device by wire. Reference numeral 114 denotes a video signal input terminal, 115 denotes an audio signal input terminal, and 116 denotes an audio signal output terminal to an external device.

  In FIG.1 (c), 117 is an optical sensor which can measure the illumination on the screen surface side to project. Reference numeral 118 denotes an outside air intake port for exhausting heat inside the projector, and is provided with a filter for removing dust in the air.

  In FIG.1 (d), 119 is AC inlet used at the time of battery charging, and is connected with an external commercial power supply with a cable. Reference numeral 120 denotes a large exhaust port for exhausting the heat inside the projector, and fins for adjusting the exhaust direction are attached.

  FIG. 2A is a diagram showing an optical path inside the projector shown in FIG. In this embodiment, the liquid crystal panel as a display element is configured by a three-plate system of R, G, and B, and the driving method of the liquid crystal panel is the same.

  Reference numeral 201 denotes a lamp serving as a light source for the projector, and a lamp with higher brightness is used as a brighter projected image is required.

  Reference numeral 202 denotes a fly-eye lens, which is used in combination with the condenser lens 204 to make the light from the light source into a uniform parallel light beam on the irradiation surface.

  Reference numeral 203 denotes a PS conversion element. The light emitted from the fly-eye lens 202 is in a random polarization state, and is an element for aligning this with P-polarized light or S-polarized light.

  Reference numeral 205 denotes a dichroic mirror, which can reflect or transmit light of a specific wavelength. In the present embodiment, the light of the green (G) wavelength is transmitted through the dichroic mirror 205, and the light of the red (R) and blue (B) wavelengths is reflected in the 90 ° perpendicular direction.

  Reference numeral 214 denotes a polarizing beam splitter (hereinafter abbreviated as PBS: Polarizing Beam Splitter), which is formed by coating a sloped surface of a 45 ° right-angle prism with a dielectric polarizing film. When a light beam is incident on this, it can be separated into transmitted light and reflected light depending on the direction of polarization.

  In this embodiment, a green light beam is incident on the PBS 214, is reflected by the adhesive surface, and is emitted by bending 90 ° toward the liquid crystal panel 215. The emitted green (G) light beam is incident on the λ / 4 phase plate 223, is further reflected on the surface of the liquid crystal panel 215, and is incident on the λ / 4 phase plate again. The liquid crystal panel 215 can change the alignment of the liquid crystal molecules by voltage, and arbitrary image information can be superimposed on the reflected light according to the alignment state. The light beam that is incident on the PBS 214 again passes through the λ / 4 phase plate twice, so that the polarization direction is rotated by 90 °. (Hereinafter, abbreviated as HBC: Hybrid Beam Combiner).

  On the other hand, red (R) and blue (B) light beams are emitted from the dichroic mirror 205 in a direction perpendicular to 90 °, enter the color select element 221 after passing through the polarizing plate 222. The color select element 221 transmits a light beam having a short wavelength (here, blue) as it is, but behaves in the same manner as a λ / 2 phase plate when a light beam having a long wavelength (here, red) is transmitted. That is, the red light beam is emitted with the polarization direction rotated by 90 °.

  For this reason, the blue light beam is reflected in the 90 ° direction at the joint surface of the PBS 206, transmitted through the λ / 4 phase plate 219, reflected by the liquid crystal panel 207, transmitted again through λ / 4, and then enters the PBS. In the PBS 206, since the polarization direction is rotated by 90 ° from the time of the first incident, the light is transmitted without being reflected by the PBS joint surface and is incident on the HBC 213.

  Since the red light beam is incident on the PBS 206 with the polarization direction rotated by 90 ° with respect to the blue light beam, the red light beam is transmitted without being reflected by the PBS joint surface, transmitted through the λ / 4 phase plate 220, and reflected by the liquid crystal panel 208. After passing through λ / 4 again, it enters the PBS. In the PBS 206, since the polarization direction is rotated by 90 ° from the time of the first incident, it is reflected without passing through the PBS joint surface and is incident on the HBC 213.

  As described above, the reflected light rays from the RGB liquid crystal panels are incident on the HBC 213. The HBC 213 is an optical element having both properties of a dichroic mirror and PBS. In this embodiment, it plays the role of combining the incident RGB light beams, and the combined light beam is emitted to the projection lens 102 side. The light beam magnified by the projection lens 102 projects an image on the screen.

  The above is the description of the first optical path related to normal projection.

  Next, the second optical path related to dust detection will be described.

  Most of the light beams are emitted in the direction of the projection lens 102 at the joint surface of the HBC 213, but a part of the synthesized light is emitted as leakage light in a direction bent by 90 °. The optical path for imaging this leaked light on the image sensor surface is the second optical path.

  An optical aperture 212 is used to adjust the amount of light to an appropriate amount when capturing the leaked light with the image sensor 210.

  The imaging element 210 is an image sensor, and is an element that converts light incident on the imaging surface into an electrical signal. The image sensor 210 may also be used for purposes other than the application of the present embodiment when detecting flicker or adjusting white balance (color adjustment).

  Reference numeral 209 denotes a neutral density filter which complements the optical aperture 212.

  Reference numeral 211 denotes a movable focus lens for forming an image of leakage light on the surface of the image sensor 210. By adjusting the lens 211, it is arranged on the surface of each of the RGB liquid crystal panels 207, 208, and 215 or in the vicinity thereof. It is possible to focus on the surface of each λ / 4 phase plate 219, 220, 223.

  Reference numerals 216, 217, and 218 denote dust removing fans for blowing off dust adhering to the vicinity of the RGB liquid crystal panels 207, 208, and 215 or the λ / 4 phase plates 219, 220, and 223, respectively.

  A broken line 252 indicates a path through which the leakage light of the green light (G) from the liquid crystal panel 215 reaches the image sensor 210. Similarly, a broken line 251 indicates a path through which the leaked light of the blue light (B) from the liquid crystal panel 207 reaches the image sensor 210, and a broken line 250 indicates a leaked light of the red light (R) from the liquid crystal panel 208 from the HBC 213. Indicates paths to the image sensor 210.

  FIG. 3 is a block diagram showing components such as an LSI, a sensor, an actuator, a light source, and a power source for causing the projector shown in FIGS. 1 and 2 to function.

  Reference numeral 301 denotes a one-chip microcomputer for scaling and color correcting a video signal input from an external video signal output device in an analog or digital format to the resolution of the projector liquid crystal panel (hereinafter referred to as video signal processing). Called a microcomputer).

  When the video signal processing microcomputer 301 detects an input from the digital video input terminal 111, the analog video input terminal 112, or the concept data communication terminal, the input video signal is decoded in the case of a digital signal, and in the case of an analog signal. A / D conversion is performed to perform resolution conversion (scaling) so that the display resolution of the liquid crystal panels 207, 208, and 215 is reached, and video data is sent to the liquid crystal panel driver 313 in a predetermined format. During this time, color correction and trapezoidal correction can be performed.

  The liquid crystal panels 207, 208, and 215 receive control signals and video data from the liquid crystal panel driver 313 and display images.

  303 is a sensor built in the projector, such as signal control from the operation buttons 103 to 110 of the projector, a cooling fan 314, a lamp control circuit 314 that controls lighting of a high-intensity lamp, and a plurality of temperature sensors 316 that detect the temperature in the housing, A microcomputer (hereinafter referred to as a projector control microcomputer) that performs overall control of the entire actuator.

  Upon receiving a zoom control instruction from the operation buttons 103 to 110, the projector control microcomputer 303 sends a signal to the motor driver circuit 312 to drive the zoom motor 317 to control the projection lens.

  Reference numeral 316 denotes a temperature sensor attached to the periphery of the lamp 318, and the projector control microcomputer 303 determines values from these sensors and controls the rotational speed of the cooling fan 314 to adjust the air volume.

  Reference numeral 311 denotes a focusing motor for focusing the projection lens 102 on the screen surface, and the projector control microcomputer 303 controls and drives the motor driver 312.

  Reference numeral 302 denotes a microcomputer for decoding a signal input from the high-speed digital data communication port 113 and converting it into a signal format that can be processed by the video signal processing microcomputer 301.

  Reference numeral 309 denotes a projector AC-DC power conversion circuit which supplies DC power used by the projector from a commercial power source.

  Reference numeral 315 denotes a lamp control circuit which receives a command from the projector control microcomputer 303 and generates a high voltage necessary for lighting the lamp 318.

  Reference numerals 306 and 321 denote non-volatile memories, which store programs and data of connection destination microcomputers, respectively. Reference numerals 307 and 308 denote volatile memories, which are used for the frame buffer of the projected image and the calculation in the microcomputer.

  Reference numeral 323 denotes a motor for driving the focus lens 211 that focuses the leaked light from the HBC 213 onto the surface of the image sensor 210, and is controlled by the motor driver 322.

  Reference numeral 325 denotes a picked-up image processing microcomputer, which determines a dust adhesion state from an image obtained by picking up an image of the vicinity of the panel surface with the image pickup device 210. The determined information is notified to the projector control microcomputer 303.

  The nonvolatile memory 328 stores a program for the imaging processing microcomputer 325, and the volatile memory 327 is used as a temporary storage memory for the imaging processing microcomputer 325.

  FIG. 4 shows a flowchart of this embodiment.

  First, the projector is pressed by pressing the power button 103 (S401).

  In this state, the video signal processing microcomputer 201 resets a counter N_red (hereinafter, dust detection counter) for detecting the dust removal operation of the red light liquid crystal panel 208 to zero (S402).

  Next, in order to image the dust adhesion state on the surface of the liquid crystal panel 207, the focus lens 211 disposed in the second optical path is controlled to a position preset by the captured image processing microcomputer 325 (S403). .

  After the elapse of X time, a test image for detecting dust is displayed for one frame (S404). Here, the test image for dust detection refers to a solid red image, and the reflected light from the liquid crystal panels 207 and 215 other than the red light disappears during display. That is, only the reflected light from the red liquid crystal panel 208 can be imaged for one frame. This state is shown at 701 in FIG. Further, the time interval for inserting the dust detection test image, that is, the interval X for performing the dust detection and removal may be uniquely determined or may be changed depending on the use environment. For example, when the projector is used in an environment where there is a lot of dust, by reducing the value of X, it is possible to frequently check the state of dust adhesion during operation, and to suppress dust adhesion.

  Next, in synchronization with the test image being displayed in one frame, the image from the image sensor 210 is captured by the imaging processing microcomputer 325 (S405). The captured image data includes a surface state of the liquid crystal panel 208 of red light as indicated by reference numeral 701 in FIG. If dust is attached, it is reflected as a bright spot or dark spot different from the surrounding color.

  The imaging data is subjected to image processing by the imaging processing microcomputer 325, and the amount of dust adhering to the surface of the liquid crystal panel 208 is determined (S406). When it is determined that there is dust exceeding the allowable value and the dust detection counter is smaller than a predetermined value (10 in this embodiment) (S421), the projector control microcomputer 303 rotates the fan 216 for dust removal, Control is performed to blow off dust (S423). Subsequently, the dust detection counter is incremented by 1 (S424), and the process returns to the process of displaying the dust detection test image after X hours (S404). Also, if the number of dust detection counters exceeds 10 in the process (S406), that is, if the dust cannot be removed even after the dust removal operation is repeated 10 times, the red light liquid crystal panel has dust. Is displayed (S422), and the flow is completed (S414). An example of the display screen at this time is shown in FIG. On the other hand, if it is determined in the processing (S406) that there is no dust adhering to the red light liquid crystal panel, the dust detection counter N_grn of the green light liquid crystal panel 215 is reset to zero (S407).

  Next, in order to image the adhesion state of dust on the surface of the liquid crystal panel 215, the focus lens 211 disposed in the second optical path is controlled to a position preset by the captured image processing microcomputer 325 (S408). .

  Thereafter, after a lapse of X hours, a dust detection test image is displayed for one frame (S409). Here, the test image indicates a green solid image, and the reflected light from the liquid crystal panels 207 and 208 other than the green light disappears during display. In other words, only the reflected light from the red light liquid crystal panel 215 can be captured for one frame. This state is shown at 702 in FIG.

  Thereafter, the same processing as that for the red light liquid crystal panel 208 is repeated (S410 to S411, S431 to S434).

  After the dust detection and removal work is completed for the green light liquid crystal panel, the dust detection counter N_blue of the blue light liquid crystal panel 208 is reset to zero (S412). The same processing is repeated (S413 to S416, S441 to S444).

  However, a blue plain image is used as the test image for dust detection (703 in FIG. 7).

  By repeating the above series of operations during projection, it is possible to suppress the adhesion of dust to the surfaces of the liquid crystal panels 207, 208, and 215. Further, in this embodiment, it is possible to detect the adhesion of dust even during image projection, so that it is not necessary to request the user to interrupt use or perform a special operation.

  Next, a second embodiment will be described. The basic configuration is the same as that of the first embodiment, and only different parts in the configuration will be described below.

  FIG. 2B is a diagram showing an optical path inside the projector shown in FIG.

  In this embodiment, instead of the dust removal fan shown in the first embodiment, the piezoelectric elements 220, 221, and 222 for vibrating the RGB liquid crystal panels 207, 208, and 215 to shake off the dust are the liquid crystals. Bonded to the panel. Other configurations are the same as those described in the first embodiment.

  FIG. 5 shows a flowchart of this embodiment.

  First, the power button 103 is operated to turn off when the power is already on, and turn on when the power is off (S501).

  Next, in order to image the adhesion state of dust on the surface of the red light liquid crystal panel 207, the focus lens 211 disposed in the second optical path is controlled from the captured image processing microcomputer 325 to a preset position (S502). .

  Subsequently, a test image for dust detection is displayed (S503). As in the first embodiment, the dust detection test image here refers to a red solid image, and the reflected light from the liquid crystal panels 207 and 215 other than the red light disappears during display. That is, since an image of the surface of the liquid crystal panel 208 of red light is formed on the imaging surface of the imaging device 210, this state is captured (S504).

  The imaging data is subjected to image processing by the imaging processing microcomputer 325, and the amount of dust adhering to the surface of the liquid crystal panel 208 is determined (S505). If it is determined that there is dust exceeding the allowable limit, the projector control microcomputer 303 drives the piezoelectric element 221 bonded to the liquid crystal panel 208 to shake off dust adhering to the panel surface (S506). . In order to image the state of dust adhesion on the surface of the green liquid crystal panel 207, the focus lens 211 disposed in the second optical path is controlled to a preset position from the captured image processing microcomputer 325 (S508). On the other hand, if it is determined in the process (S505) that the quantity of dust is within the allowable range, the process proceeds to the process (S508) without performing the dust removal process.

  Thereafter, the same processing as that for the red light liquid crystal panel 208 is repeated (S508 to S511).

  Finally, the same processing as the other two panels is repeated for the blue light liquid crystal panel 215 (S512 to 516), and the dust detection and removal processing is completed (S517).

  By performing the above series of operations, dust attached to the surfaces of the liquid crystal panels 207, 208, and 215 during use of the projector can be removed. Further, in this embodiment, the processing is performed immediately after the power ON / OFF sequence, so that the user does not have to perform a special operation. In addition to the power ON or OFF sequence, the dust removal operation may be performed when the input video is switched. Furthermore, in this embodiment, the detection and removal of dust attached to the surfaces of the liquid crystal panels 208, 209, and 215 are specialized. However, by adjusting the focus lens 250, the λ / 4 phase plates 219, 220, and 223 are adjusted. It is also possible to take an image of dust adhering to the surface.

  As mentioned above, although preferred embodiment of this invention was described as Example 1, 2, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

207, 208, 215 liquid crystal panel, 209 neutral density filter, 210 image sensor,
211 Focus lens, 325 imaging image element microcomputer,
216 to 218 Dust removing fan, 220 to 222 Piezoelectric element

Claims (10)

A projector having a single or a plurality of display elements, and a first optical path from the display elements to the projection lens, and a second light for efficiently condensing and imaging the leaked light therefrom The second optical path has a configuration in which an imaging element and a movable movable lens for focusing to form an image on the imaging element surface are arranged in the second optical path. A projector characterized in that, by adjusting a movable lens, the display element in the first optical path, the adjacent optical component, and the surface of the lens are focused, and the state of dust adhering thereto is imaged. The projector according to claim 1, wherein the image sensor disposed in the second optical path is also used as a sensor for flicker detection or white balance correction. By pre-setting the focus element to the display element of the focus lens in the second optical path, the lens disposed adjacently, and the focus position to the optical component position, at a high speed and accurately, 3. The projector according to claim 1, wherein the display element, an adjacent optical component, and a lens surface are focused, and an image of a dust adhesion state can be imaged. When the shape and size of dust on the display element, adjacent optical components and lens surface are extracted and determined from the data of the image sensor, and the adhesion of a certain amount or more of dust is detected, it is displayed on the projection screen. The projector according to any one of claims 1 to 3, wherein a warning display is performed. The display device and the adjacent optical component, a projector having a device for removing dust adhering to the lens surface by wind pressure, and from the data of the imaging device, the display device and the adjacent optical component, The shape and size of the dust on the lens surface is extracted and determined, and when dust of a certain level or more is detected, they are blown off by applying wind pressure to the specified part. 4. The projector according to any one of 3. The display element and the adjacent optical component, a projector having a device for removing dust attached to the lens surface by vibration, and from the data of the image sensor, the display element and the adjacent optical component, 2. The shape and size of dust on the lens surface is extracted and determined, and when dust of a certain level or more is detected, the part where the dust is detected is shaken off by the vibration device. The projector according to claim 3. 7. The display device according to claim 1, wherein the display element or the adjacent optical component, the imaging of the lens surface, and the dust detection or removal operation are performed during image projection. projector. 7. The display element or an adjacent optical component, imaging of a lens surface, and dust detection and removal operations are performed when the power is turned on or when the power is turned off. Projector. The projector according to any one of claims 1 to 6, wherein the display element or an adjacent optical component, imaging of a lens surface, and dust detection and removal operations are performed when video input is switched. . In order to make it easier to extract the number and shape of dust adhering to the display element, adjacent optical components, and dust on the lens surface from the data from the imaging element, a specific image is projected at the time of imaging. The projector according to any one of claims 1 to 9.