JP2004045809A - Projector inspection apparatus and projector inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector inspection apparatus capable of exactly discriminating the normal/defective condition of a projector by exactly inspecting the optical characteristics of the projector. <P>SOLUTION: The projector inspection apparatus is provided with a reflector body 721 which reflects the projected light from the projector 1, a reflector moving mechanism 722 which advances and retreats the reflector body, a transmission screen 71 on which the projected images of the reflected light are foemed, three CCD (Charge Coupled Device) cameras 81 which imagethe projected images from the back side, and a computer 90 which performs image processing in accordance with the image signals captured by a video capturing board 100. The computer is provided with a focus position adjusting section 92 which controls the driving of the reflector moving mechanism so as to match the foci of the picked up images, a moving quantity acquiring section 93 which acquires the moving quantities of the reflector body from its reference position after the adjustment by each of three color light rays, an axial chromatic aberration measuring section 94 which measures axial chromatic aberrations based on these moving quantities and a normal/defective condition deciding section 98 which decides the normal/defective condition of the projector based on the axial chromatic aberration values. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projector inspection device and a projector inspection method.
[0002]
[Background Art]
2. Description of the Related Art Conventionally, a projector that modulates a light beam emitted from a light source according to image information and projects it on a screen via a projection lens is known, and is widely used for multimedia presentations at conferences, conferences, exhibitions, and the like. .
As such a projector, a light source lamp, a color separation optical system that separates a light beam emitted from the light source lamp into three color lights R, G, and B using a dichroic mirror, and a light separation lamp that separates these separated light beams Three light modulators that modulate each color light in accordance with image information, a cross dichroic prism that combines light beams modulated by each light modulator to form an optical image, and enlarges the combined optical image. There is known a so-called three-plate type projector including a projection lens for projecting light.
[0003]
At the time of manufacturing such a projector, a focus adjustment for accurately arranging each liquid crystal panel at the back focus position of the projection lens and a pixel of each liquid crystal panel between each liquid crystal panel to obtain a clearer projected image. It was necessary to perform the alignment adjustment to make them coincide with each other with high precision. In particular, with the miniaturization and high brightness of the projector, more accurate adjustment has been required.
Therefore, in the focus / alignment adjustment of the liquid crystal panels, for example, an optical device including three liquid crystal panels and a cross dichroic prism is to be adjusted. The relative position of each liquid crystal panel is adjusted by adjusting the position and orientation of each liquid crystal panel while imaging a light beam incident from the light incident end face and emitted from the light output end face with a CCD camera.
[0004]
Here, as an image pickup by a CCD camera, a standard projection lens is preliminarily incorporated as a master lens in a manufacturing apparatus, an optical device and a light beam passing through the projection lens are projected onto a screen, and a method of capturing the projection image ( (A master lens system) and a system (direct-view system) for directly taking in a light beam having passed through an optical device. By adopting such a method, the optical device can be inspected independently without combining with the projection lens, which has been efficient.
[0005]
[Problems to be solved by the invention]
However, in the inspection of the optical device by any method, since the adjustment is performed based on the light source light of the specific wavelength using the specific reference light source, the adjustment is not necessarily performed in the case of the projector as a completed product using the light source actually incorporated. There is a problem that they do not match, and the quality of the projector may not be determined strictly.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a projector inspection apparatus and a projector inspection method capable of accurately inspecting the optical characteristics of a completed projector and accurately determining the quality of the projector.
[0007]
[Means for Solving the Problems]
A projector inspection apparatus according to the present invention includes a light source, an optical device that modulates a light beam emitted from the light source according to image information to form an optical image, and enlarges and projects the optical image emitted from the optical device. A projector inspection apparatus for inspecting the quality of a projector including a projection optical system, based on an installation table on which a projector to be inspected is installed and an optical image enlarged and projected from the inspection object installed on the installation table A transmission screen device on which a projection image is formed, a screen device moving mechanism capable of moving the transmission screen device in the forward / backward direction with respect to the projection optical system, and a transmission screen device installed on the back side of the transmission screen device; An image pickup apparatus including an image pickup element for picking up an image projected on a transmissive screen device; And an image processing device that performs an arithmetic operation on an image based on an image signal captured by the image capturing device. A focus position adjustment unit that performs drive control of the screen device moving mechanism so that the focus of the projection image matches, and the transmission after the focus adjustment by the focus position adjustment unit for each of a plurality of color lights forming the projection image A moving amount obtaining unit that obtains a moving amount from a reference position of the screen device, and an axial chromatic aberration measuring unit that measures axial chromatic aberration of a projected image based on the obtained moving amount of each color light, A quality judgment unit for judging the quality of the projector to be inspected based on the measured value of the axial chromatic aberration.
[0008]
Here, the transmission screen device includes, in addition to the configuration of only the transmission screen, a configuration in which a reflection mirror as a reflection device is combined with the transmission screen.
The plurality of color lights may be, for example, three color lights of red (R), green (G), and blue (B).
As an image pickup device constituting the image pickup apparatus, a CCD (Charge Coupled Device) or the like can be adopted. As an image pickup device, a device provided with a CCD and filters of three colors of red (R), green (G), and blue (B), which is disposed at a stage before the optical path of the CCD, and a red (R), green (G) ) And a device having a so-called 3CCD, which decomposes light beams of three colors of blue (B). A video capture board can be used for the image capturing device. The image processing device can be configured as a computer. For this reason, the focus position adjustment unit, the movement amount acquisition unit, the axial chromatic aberration measurement unit, and the pass / fail determination unit are each configured to control the operation of a computer to which an image signal from the image sensor is input via the image capturing device. It can be configured as an image processing program developed on an Operating System.
[0009]
With the projector inspection device of the present invention, for example, inspection can be performed as follows.
(1) A projector to be inspected is installed on an installation table, and a light beam is emitted from a light source to project an all-white image (normally white) on a screen device.
(2) The transmissive screen device is set at a position (reference position) that is a reference projection distance from the projector, and the imaging device including 3 CCDs starts capturing an all-white image.
(3) While imaging with the 3CCD, for example, the screen device moving mechanism is driven and controlled by the focus position adjustment unit of the image processing device based on the green light component of the projected image to move the screen device forward and backward, thereby focusing the projected image. Make adjustments. At this time, the position at the time of focusing is acquired, and the movement amount from the reference position is acquired by the movement amount acquisition unit. Similarly, the movement amounts from the reference position are acquired for the projection image based on the red light component and the blue light component.
(4) The axial chromatic aberration is measured by the axial chromatic aberration measurement unit based on the difference in the amount of movement acquired for each of the color lights.
(5) The pass / fail judgment unit judges pass / fail of the projector based on whether or not the measured value of the longitudinal chromatic aberration is within the range of non-defective products.
(6) The measurement result of the axial chromatic aberration obtained is stored in a storage device or the like of the image processing apparatus in a state where the measurement result corresponds to the product number or the like of the completed product to be inspected, and the inspection ends.
[0010]
According to the present invention, by performing the inspection according to the above-described procedure, the inspection can be performed with the light source used for the projector to be inspected, and the axial chromatic aberration of the projector can be easily and accurately inspected. By this inspection, the quality of the projector to be inspected can be accurately determined. For this reason, a projector capable of projecting high-quality images can be reliably provided on the market. In addition, all the inspections can be performed as automatic inspections to improve the efficiency of the inspection.
[0011]
Here, it is preferable that the imaging device includes a plurality of imaging elements for decomposing a projection image formed on the transmission screen device into a plurality of color lights.
In this case, by adopting the 3CCD as an image pickup device for decomposing into a plurality of color lights, for example, an image for each RGB can be obtained almost simultaneously as compared with a case where each color light is imaged using a color filter corresponding to RGB. Since imaging can be performed, inspection efficiency can be improved.
In addition, by arranging a plurality of image sensors, for example, four corresponding to four corners which are outer peripheral ends of a rectangular projected image, and performing inspection at a plurality of locations of the projected image, it is possible to improve the accuracy of the inspection. it can.
[0012]
In the above, the imaging device includes an imaging device moving mechanism that moves the plurality of imaging devices along the projection surface of the transmission screen device, and the image processing device is formed in the transmission screen device. An image sensor adjustment unit that drives and controls the image sensor moving mechanism so as to image the outer edge of the projected image, and moves to a position corresponding to the outer edge of the projected image; An outer peripheral end position acquisition unit that acquires the position of each image sensor for each of the plurality of color lights, and a magnification chromatic aberration measurement unit that measures the magnification chromatic aberration based on the position of each image sensor acquired for each of the color lights. It is preferable that the quality judgment unit judges the quality of the projector to be inspected based on the measured value of the chromatic aberration of magnification.
[0013]
Here, for example, after inspecting the axial chromatic aberration in the projector inspection device, the chromatic aberration of magnification can be inspected in the following procedure.
(A) First, a projection image is set as a frame-like image in which a white frame is formed on a black background. Next, for example, the green light component of the frame-shaped projection image, drive control of the image sensor moving mechanism in the image sensor adjustment unit, so that the outer peripheral edge of the four corners of the white frame of the projection image can be imaged, The four image sensors, which are a plurality of image sensors, are moved to the respective four corners.
(B) The position of each image sensor based on the green light component is acquired by the outer peripheral end position acquisition unit. Similarly, the position of each image sensor is acquired for the projected image based on the red light component and the blue light component.
(C) The chromatic aberration of magnification is measured by the chromatic aberration of magnification measuring unit by determining the difference between the positions of the image sensors obtained for each of the color lights for each corner.
(D) The pass / fail judgment unit judges pass / fail of the projector based on whether the measured value of the chromatic aberration of magnification is within the range of a non-defective product.
(E) Store the obtained measurement result of the chromatic aberration of magnification together with the previously obtained axial chromatic aberration in the storage device or the like of the image processing apparatus in a state where the measurement result corresponds to the product number of the completed product to be inspected. , End the inspection.
[0014]
In this case, by performing the inspection according to the above procedure, the chromatic aberration of magnification can be easily and accurately inspected in addition to the axial chromatic aberration of the projector to be inspected. The quality of the target projector can be accurately determined. For this reason, a projector capable of projecting high-quality images can be reliably provided on the market.
[0015]
In the above, the transmission screen device includes a reflection device that reflects an optical image enlarged and projected from the inspection target, and a transmission screen on which a projection image based on the optical image reflected by the reflection device is formed. It is preferable that the screen device moving mechanism is configured to be able to move the reflection device in a forward / backward direction with respect to the projection optical system.
In this case, for example, a transmissive screen is arranged between the projection optical system of the projector and the reflection device, and the image light emitted from the projection optical system is reflected toward the projection optical system to form a transmissive screen. A projection image based on image light is formed on the projection screen, and the projection image is inspected by an imaging device disposed between the projection optical system and the transmission screen. At this time, the transmission screen may have a configuration in which an opening is formed so as not to hinder the optical path of the image light projected from the projection optical system.
With such a configuration, the size of the inspection device can be reduced as compared with a case where the projection optical system, the transmission screen, and the imaging device are arranged on a straight line.
Further, instead of the transmissive screen, the reflecting mirror, which is a reflecting device for reflecting image light, is moved, so that the moving amount can be reduced, the inspection time can be shortened, and the efficiency can be improved.
[0016]
A projector inspection method according to the present invention includes a light source, an optical device that modulates a light beam emitted from the light source according to image information to form an optical image, and enlarges and projects the optical image emitted from the optical device. A projector inspection method for inspecting the quality of a projector including a projection optical system, wherein an enlarged image of an optical image is projected from a projector to be inspected installed on an installation table to form a projection image on a screen device. Procedure, while imaging the formed projection image for each of a plurality of color lights with an image sensor, the transmission type screen device to the adjustment target projection optical system such that the focus of the projection image for each color light matches. A procedure for moving the screen apparatus forward and backward, a procedure for acquiring the amount of movement of the screen apparatus from the reference position for each color light, An axial chromatic aberration measurement procedure for measuring the axial chromatic aberration of the projected image based on the measured amount of movement for each color light, and determining whether the projector to be inspected is good or bad based on the measured axial chromatic aberration value A pass / fail judgment procedure.
[0017]
According to the present invention, similarly to the projector inspection apparatus, the axial chromatic aberration of the projector to be inspected can be easily and accurately inspected, and the quality of the projector to be inspected can be accurately determined by this inspection. Can be determined. For this reason, a projector capable of projecting high-quality images can be reliably provided on the market.
[0018]
In the above projector inspection method, the imaging device moving mechanism moves each of the plurality of imaging devices so as to capture an outer peripheral end of a projection image formed on the transmission screen device in the projection image forming procedure. An element adjustment procedure, an outer peripheral end position acquisition procedure for acquiring the moved position of each image sensor for each of a plurality of color lights, and a magnification chromatic aberration of a projection image based on the position of each image sensor acquired for each of the color lights. It is preferable that the quality determination step determines the quality of the projector to be inspected based on the measured value of the chromatic aberration of magnification.
[0019]
In this case, similarly to the inspection apparatus of the projector, for example, after measuring the axial chromatic aberration, by measuring the chromatic aberration of magnification in the above procedure, in addition to the axial chromatic aberration of the projector to be inspected, The chromatic aberration of magnification can also be easily and accurately inspected, and the quality of the projector to be inspected can be accurately determined by these inspections. For this reason, a projector capable of projecting high-quality images can be reliably provided on the market.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[1. Configuration of projector)
FIG. 1 is a perspective view of a projector 1 according to an embodiment of the present invention as viewed from above. FIG. 2 is a perspective view of the projector 1 as viewed from below.
1 and 2, the projector 1 includes an outer case 2 having a substantially rectangular parallelepiped shape. The outer case 2 is a synthetic resin housing for housing the main body of the projector 1, and includes an upper case 21, a lower case 22, and a front case 23 attached so as to straddle the front sides of these cases 21 and 22. And
[0021]
As shown in FIG. 1, the upper case 21 is configured to include an upper surface 211, a side surface 212, and a rear surface 213 that configure the top surface, the side surface, and the rear surface of the projector 1, respectively. An operation panel 25 is provided on the front side of the upper surface portion 211. Further, as shown in FIG. 2, in the upper case 21, a concave portion 21 </ b> A is formed on the rear side of the operation panel so as to straddle the rear side of the upper surface portion 211 and the rear surface portion 213. A part of the circuit board 5 housed in the outer case 2 is exposed to the outside from the recess 21A. The parts of the circuit board 5 exposed to the outside are various connectors 5A constituting an interface unit. External devices are connected to the projector 1 via these connectors 5A.
[0022]
As shown in FIG. 2, the lower case 22 includes a bottom part 221, a side part 222, and a back part 223 that constitute the bottom, side, and back of the projector 1, respectively.
An opening 221X is formed in the bottom surface 221. The lamp cover 24 is fitted and detachably provided in the rectangular opening 221X. Further, the bottom surface 221 is formed with air inlets 221A and 221B for sucking cooling air from outside.
[0023]
In the bottom portion 221, a rear leg 22 </ b> R that forms a leg of the projector 1 is formed at a substantially central portion on the rear side. Front legs 22F, which also constitute the legs of the projector 1, are provided at the left and right corners on the front side of the bottom surface 221 respectively. That is, the projector 1 is supported at three points by the rear leg 22R and the two front legs 22F.
The two front legs 22F are configured to be able to advance and retreat in the vertical direction, respectively, so that the inclination (posture) of the projector 1 in the front-rear direction and the left-right direction can be adjusted to adjust the position of the projection image.
[0024]
As shown in FIG. 1, the front case 23 includes a front part 231, a top part 232, and a side part 233 that constitute the front, top, and side surfaces of the projector 1, respectively.
The front case 23 has an opening 23 </ b> A that straddles the front part 231 and the top part 232. A projection lens 46 is arranged inside the outer case 2 so as to correspond to the opening 23A. At this time, a part of the projection lens 46 is exposed to the outside from the opening 23A, and the zoom operation and the focus operation of the projection lens 46 can be manually performed through a lever 46A which is a part of the exposed part. Has become.
[0025]
In the front part 231, an exhaust port 23B is formed as an opening at a position opposite to the above-described opening 23A. An exhaust duct 67 that guides the air inside the projector 1 is provided inside the exhaust port 23B, and an exhaust port of the exhaust duct 67 faces the exhaust port 23B. An external louver 23 </ b> B <b> 1 on the outside of the projector 1 is formed in the exhaust port 23 </ b> B.
[0026]
As shown in FIG. 1, an intake port 2 </ b> A is formed on the side surface of the outer case 2 so as to straddle the side surface 212 of the upper case 21 and the side surface 222 of the lower case 22. A sirocco fan (not shown) is provided inside the intake port 2A.
[0027]
FIG. 3 is a plan view schematically showing the optical unit 4.
As shown in FIG. 3, the optical unit 4 includes an integrator illumination optical system 41, a color separation optical system 42, a relay optical system 43, an optical device 44, and a projection lens 46 as a projection optical system.
[0028]
The integrator illumination optical system 41 illuminates the image forming regions of the three liquid crystal panels 441 (which constitute the liquid crystal panels 441R, 441G, and 441B for each of red, green, and blue color lights) constituting the optical device 44 substantially uniformly. And a light source device 411, a first lens array 412, a second lens array 413, a polarization conversion element 414, and a superimposing lens 415.
[0029]
The light source device 411 includes a light source lamp 416 as a radiation light source and a reflector 417. Radial rays emitted from the light source lamp 416 are reflected by the reflector 417 into parallel rays, and the parallel rays are emitted to the outside. .
As the light source lamp 416, a halogen lamp is used. In addition to the halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or the like can be used.
As the reflector 417, a parabolic mirror is employed. Instead of the parabolic mirror, a combination of a parallelizing concave lens and an elliptical mirror may be employed.
[0030]
The first lens array 412 has a configuration in which small lenses having a substantially rectangular outline when viewed from the optical axis direction are arranged in a matrix. Each small lens divides a light beam emitted from the light source lamp 416 into a plurality of partial light beams. The contour shape of each small lens is set to be substantially similar to the shape of the image forming area of the liquid crystal panel 441. For example, if the aspect ratio (the ratio of the horizontal and vertical dimensions) of the image forming area of the liquid crystal panel 441 is 4: 3, the aspect ratio of each small lens is also set to 4: 3.
[0031]
The second lens array 413 has substantially the same configuration as the first lens array 412, and has a configuration in which small lenses are arranged in a matrix. The second lens array 413 has a function of forming an image of each small lens of the first lens array 412 on the liquid crystal panel 441 together with the superimposing lens 415.
[0032]
The polarization conversion element 414 is disposed between the second lens array 413 and the superimposing lens 415, and is unitized integrally with the second lens array 413. Such a polarization conversion element 414 converts the light from the second lens array 413 into one type of polarized light, thereby increasing the light use efficiency of the optical device 44.
[0033]
Specifically, each partial light converted into one type of polarized light by the polarization conversion element 414 is almost superimposed on the liquid crystal panel 441 of the optical device 44 finally by the superimposing lens 415. In the projector 1 using the liquid crystal panel 441 of the type that modulates polarized light, only one type of polarized light can be used, so that almost half of the light from the light source lamp 416 that emits another type of randomly polarized light is not used. Therefore, by using the polarization conversion element 414, all the light fluxes emitted from the light source lamp 416 are converted into one kind of polarized light, and the light use efficiency of the optical device 44 is increased.
In addition, such a polarization conversion element 414 is introduced in, for example, Japanese Patent Application Laid-Open No. 8-304739.
[0034]
The color separation optical system 42 includes two dichroic mirrors 421 and 422 and a reflection mirror 423, and converts a plurality of partial light beams emitted from the integrator illumination optical system 41 by the dichroic mirrors 421 and 422 into red (R) and green. (G) and blue (B).
[0035]
The relay optical system 43 includes an incident-side lens 431, a relay lens 433, and reflection mirrors 432 and 434, and has a function of guiding red light, which is the color light separated by the color separation optical system 42, to the liquid crystal panel 441R. ing.
[0036]
At this time, the dichroic mirror 421 of the color separation optical system 42 transmits the red light component and the green light component of the light beam emitted from the integrator illumination optical system 41 and reflects the blue light component. The blue light reflected by the dichroic mirror 421 is reflected by the reflection mirror 423, passes through the field lens 418, and reaches the blue liquid crystal panel 441B. The field lens 418 converts each partial light beam emitted from the second lens array 413 into a light beam parallel to its central axis (principal ray). The same applies to the field lens 418 provided on the light incident side of the other liquid crystal panels 441G and 441B.
[0037]
Further, of the red light and the green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422, passes through the field lens 418, and reaches the liquid crystal panel 441G for green. On the other hand, the red light passes through the dichroic mirror 422, passes through the relay optical system 43, further passes through the field lens 418, and reaches the liquid crystal panel 441R for red light.
The relay optical system 43 is used for the red light because the length of the optical path of the red light is longer than the length of the optical path of the other color lights, thereby preventing a reduction in light use efficiency due to light diffusion or the like. That's why. That is, this is for transmitting the partial light beam incident on the incident side lens 431 to the field lens 418 as it is.
[0038]
The optical device 44 modulates the incident light beam according to image information to form a color image. The optical device 44 includes three incident-side polarizing plates 442 on which the respective color lights separated by the color separation optical system 42 enter. A liquid crystal panel 441R, 441G, 441B as a light modulation device disposed downstream of each incident-side polarizing plate 442; an emission-side polarization plate 443 disposed downstream of each of the liquid crystal panels 441R, 441G, 441B; A cross dichroic prism 444 as an optical system is provided.
[0039]
The liquid crystal panels 441R, 441G, and 441B use, for example, polysilicon TFTs as switching elements.
In the optical device 44, each color light separated by the color separation optical system 42 is modulated according to image information by these three liquid crystal panels 441R, 441G, 441B, the incident side polarizing plate 442, and the exit side polarizing plate 443. Forming an optical image.
[0040]
The incident side polarizing plate 442 transmits only polarized light in a certain direction and absorbs other light fluxes of the respective color lights separated by the color separation optical system 42, and a polarizing film is attached to a substrate such as sapphire glass. It was done.
The emission-side polarizing plate 443 is also configured in substantially the same manner as the incidence-side polarizing plate 442, and transmits only polarized light in a predetermined direction among light beams emitted from the liquid crystal panel 441 (441R, 441G, 441B), and transmits other light beams. It absorbs.
The incident-side polarizing plate 442 and the exit-side polarizing plate 443 are set such that the directions of the polarization axes are orthogonal to each other.
[0041]
The cross dichroic prism 444 combines the optical images emitted from the emission-side polarizing plate 443 and modulated for each color light to form a color image.
The cross dichroic prism 444 is provided with a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light in a substantially X-shape along the interface of the four right-angle prisms. The three color lights are synthesized by the multilayer film.
[0042]
The projection lens 46 enlarges and projects the color image synthesized by the cross dichroic prism 444 of the optical device 44.
[0043]
The optical systems 41 to 44 described above are accommodated in a synthetic resin light guide (not shown). The light guide includes a lower light guide formed with a groove into which the optical components 412 to 415, 418, 421 to 423, 431 to 434, and 442 are slidably fitted from above, and an upper opening side of the lower light guide. And a lid-shaped upper light guide for closing the light guide. A light source device 411 is accommodated at one end of the light guide, and a projection lens 46 is fixed to the other end of the light guide via a head.
[0044]
[2. Configuration of projector inspection device]
FIG. 4 is a side view showing the projector inspection device 10 according to the present invention. FIG. 5 is a plan view showing the projector inspection device 10.
As shown in FIGS. 4 and 5, the projector inspection device 10 includes an inspection unit main body 50 in which the manufactured projector 1 is stored and arranged, and a projection unit main body 60.
[0045]
The inspection unit main body 50 includes a UV light-shielding cover 50A and an installation table 50B that is provided inside the UV light-shielding cover and on which the projector 1 is installed.
The UV light shielding cover 50A includes a side plate 51 surrounding the installation table 50B, a bottom plate 52, a door 53 provided on the side plate 51 so as to be openable and closable, and a mounting table 54 provided below. The side plate 51 is provided with a transmission window 51A for transmitting the image light emitted from the projector 1 to the projection unit main body 60.
[0046]
The door 53 is provided when, for example, supplying or removing the projector 1 to be inspected, and is formed of an acrylic plate that does not transmit ultraviolet rays.
At the lower side of the mounting table 54, a caster 54A that facilitates movement of the inspection unit main body 50 when the apparatus is installed is provided.
[0047]
Although not shown, a screw portion for fixing the left and right front legs 22F (FIG. 2) of the projector 1 with screws is provided on the upper surface of the installation table 50B. The projector 1 is fixed at a fixed position by screwing and fixing the projector 1 on the upper surface of the installation base 50B at the screw portion.
[0048]
The projection unit main body 60 includes a screen unit 70 as a transmissive screen device, an image detection device 80 as an imaging device, and a dark room 60A that accommodates the screen unit 70 and the image detection device 80. The dark room 60 </ b> A includes a side plate 61 surrounding the screen unit 70 and the image detection device 80, a bottom plate 62 and a top plate 63, and a mounting table 64. The side plate 61 is provided with a transmission window 61A for transmitting the image light emitted from the projector 1, and a caster 64A is provided below the mounting table 64.
[0049]
The screen unit 70 projects the image light emitted from the projector 1, and includes a transmissive screen 71 arranged on the inspection unit main body 50 side of the dark room 60 </ b> A and an opposite side of the dark room 60 </ b> A on the inspection unit main body 50 side. And a reflection unit 72 disposed at the same position.
[0050]
FIG. 6 is a view of the transmission screen 71 as viewed from the rear side.
As shown in FIG. 6, the transmissive screen 71 includes a rectangular frame 711 provided around the screen, and a screen main body 712 provided inside the frame 711. The screen main body 712 can be configured, for example, by uniformly dispersing optical beads on an opaque resin layer. When a light beam enters from the side where the optical beads are disposed, the optical beads become a lens, and the light beam is converted into a lens. 712 is emitted to the back side. The screen main body 712 is provided with a transmission window 71 </ b> A that transmits image light emitted from the projection lens 46 of the projector 1.
[0051]
As shown in FIG. 4, the reflection unit 72 reflects image light emitted from the projection lens 46 of the projector 1 toward the transmission screen 71, and is a reflection device main body that is directly opposed to the projection lens 46. 721, and a reflecting device moving mechanism 722 that enables the reflecting device main body 721 to move in the forward and backward directions with respect to the projection lens 46.
[0052]
The reflection device main body 721 includes a mirror 721A arranged in the same plane according to the position of the emitted image light, a mounting plate 721B to which the mirror 721A is mounted, and a support plate 721C for supporting a lower portion of the mounting plate 721B. And The reflection surface 721A1 of the mirror 721A is configured to be orthogonal to the optical axis of the image light emitted from the projection lens 46.
[0053]
The reflection device moving mechanism 722 includes a plurality of rails 722A extending in a direction perpendicular to the plane of the transmission screen 71 on the bottom plate 62 of the dark room 60A, and wheels provided on the support plate 721C so as to be rotatable on these rails 722A. 722C, and a drive mechanism (not shown) that rotationally drives the wheels 722C.
[0054]
The image detection device 80 is a device that detects a predetermined portion in a projection image formed on the transmission screen 71, and includes four 3CCD cameras 81 provided at four corners on the back side of the transmission screen 71, and each 3CCD camera 81. A moving mechanism 82 for moving the camera 81 along the surface of the transmissive screen 71.
[0055]
The 3CCD camera 81 as an imaging device separates a projection image into a plurality of three-color lights (red, green, and blue), and captures an image of each of the separated color lights using a CCD, which is a dedicated imaging device. The projection image is detected from the rear side of the screen main body 712. The 3CCD camera 81 can freely adjust the zoom and focus by remote control.
[0056]
As shown in FIG. 6, the moving mechanism 82 includes a horizontal portion 821 extending in the horizontal direction of the frame 711, a vertical portion 822 extending in the vertical direction, and a camera mounting portion 823 to which the 3CCD camera 81 is mounted. As a result, in each of the 3CCD cameras 81, the vertical portion 822 slides horizontally with respect to the horizontal portion 821, and the camera mounting portion 823 slides vertically with respect to the vertical portion 822. It can be freely moved along.
[0057]
FIG. 7 is a diagram schematically showing a control structure of the projector inspection device 10. As shown in FIG.
As shown in FIG. 7, the projector 1 and the projection unit main body 60 in the inspection unit main body 50 are electrically connected to a computer 90 which is an image processing device.
The computer 90 includes a CPU and a storage device, controls the operation of the moving mechanism of the projection unit main body 60, and is connected to four 3CCD cameras 81 via an image capturing device such as a video capture board (not shown). I have.
[0058]
The projection image picked up by the 3CCD camera 81 is input to the computer 90 via the image capturing device, converted into an image signal suitable for the computer, and then converted to an OS for controlling the operation of the computer 90 including the CPU. Image processing is performed by the developed image processing program.
[0059]
FIG. 8 is a block diagram showing functions of the computer 90.
As shown in FIG. 8, the computer 90 includes a processing unit 91, a focus position adjustment unit 92, a movement amount acquisition unit 93, an axial chromatic aberration measurement unit 94, an imaging element adjustment unit 95, and an outer edge position acquisition. A section 96, a chromatic aberration of magnification measuring section 97, and a pass / fail determination section 98 are provided.
[0060]
The processing unit 91 converts the projection image X captured by the 3CCD camera 81 into an image signal by a video capture board 100 as an image capture device and captures the image signal, and performs an image calculation process based on the captured image signal. Part.
[0061]
The focus position adjusting unit 92 controls the driving of the reflecting device moving mechanism 722 based on the image processed by the processing unit 91 such that the focus of the image matches, and changes the position of the reflecting device main body 721. Part. Note that the focus position adjusting unit 92 is implemented for each of the three color lights.
[0062]
The movement amount acquisition unit 93 is a unit that acquires, for each color light, the movement amount of the reflection device main body 721 from the reference position when the focus is adjusted by the focus position adjustment unit 92.
The axial chromatic aberration measurement unit 94 is a unit that measures the axial chromatic aberration of the projection image X based on the movement amount of each color light acquired by the movement amount acquisition unit 93.
[0063]
Based on the substantially rectangular alignment pattern image processed by the processing unit 91, the imaging element adjustment unit 95 provides four 3CCDs at positions corresponding to the four corners Y, which are outer peripheral ends of the alignment pattern image. This is a part for controlling the driving of the moving mechanism 82 so that the camera 81 moves.
The outer peripheral end position acquisition unit 96 is a unit that acquires the position of each of the 3CCD cameras 81 moved to the position of the four corners Y of the alignment pattern image for each of the three color lights.
[0064]
The magnification chromatic aberration measurement unit 97 is a unit that measures the magnification chromatic aberration based on the position of each of the three CCD cameras 81 acquired for each of the three color lights by the outer peripheral end position acquisition unit 96.
The pass / fail determination unit 98 is a unit that determines pass / fail of the projector 1 to be inspected based on the measured values of the axial chromatic aberration and the chromatic aberration of magnification.
[0065]
[3. Projector inspection method)
In such a projector inspection apparatus 10, an inspection method of the projector 1 to be adjusted is performed based on a flowchart shown in FIG.
(1) First, the projector 1 as a completed product is set on the installation table 50B as a jig (process S1).
(2) The power of the projector 1 is turned on, the light source lamp 416 is turned on (process S2), a predetermined signal is output to the liquid crystal panels 441R, 441G, and 441B, and the projection image is set to a completely white state (normally white). (Process S3: Projected image forming procedure). Then, the light beam emitted from the light source lamp 416 enters the liquid crystal panels 441R, 441G, 441B, is synthesized by the cross dichroic prism 444, and is emitted from the projection lens 46. The emitted composite image light is reflected by the reflection device main body 721 and then projected on the transmission screen 71 to form a projection image X.
[0066]
(3) The reflecting mirror axis of the reflecting device moving mechanism 722 is driven to set the reflecting device main body 721 to the reference projection distance (process S4). Specifically, the reference projection distance from the projector 1 to the transmissive screen 71 varies depending on the product, but is approximately 1.8 m.
[0067]
(4) The lever 46A, which is a focus ring, is rotated to a position corresponding to the reference projection distance (step S5).
(5) The reflection mirror shaft is operated to move the reflection device main body 721 forward and backward with respect to the transmissive screen 71 (process S6: screen device moving procedure).
(6) While the projected image X is picked up by the four 3CCD cameras 81 located at the four corners of the projected image X and processed by the processing unit 91, the focus position adjusting unit 92 sets the three color lights at substantially the same time. The focus of the projection image X is adjusted (process S7: screen device moving procedure). At this time, the movement amount acquisition unit 93 acquires the optimum focus position for each color light based on the reference projection distance (process S8: movement amount acquisition procedure). The on-axis chromatic aberration measurement unit 94 calculates a focus position difference, which is an optimum focus position of red light and blue light with respect to the optimum focus position of green light, that is, an axial chromatic aberration, based on the obtained optimum focus positions. (Process S9: On-axis chromatic aberration measurement procedure).
[0068]
(7) Next, the pass / fail judgment unit 98 judges whether or not the red or blue focus position difference is within a range of a predetermined reference value (process S10: pass / fail judgment procedure). If determined, the projector 1 is determined to be defective. On the other hand, if it is determined that it is within the range, the process proceeds to step S11.
[0069]
(8) Next, the pass / fail determination unit 98 determines whether or not the acquired optimal focus position for each color light is within a predetermined range based on the reference projection distance (within a reference projection distance of 1.8 m ± 0.1 m). (Processing S11: pass / fail determination procedure), and when it is determined that it is not within the range, the projector 1 is determined to be defective. On the other hand, if it is determined that it is within the range, the process proceeds to step S12.
[0070]
(9) Next, the computer 90 outputs an image signal including an image pattern for alignment adjustment to each of the liquid crystal panels 441R, 441G, and 441B, and places the projected image on a black background PB and a white frame PW as shown in FIG. After the alignment pattern image P is formed in a shape (process S12), the four 3CCD cameras 81 are respectively moved by the image sensor adjusting unit 95 (process S13: image sensor adjusting procedure). The four corners Y of the white frame PW of the alignment pattern image P are searched (process S14), and the positions of the four corners Y are measured and acquired (process S15: outer peripheral edge position acquisition procedure). These operations are performed for each of the three 3CCD cameras 81 for the three color lights.
[0071]
(10) Next, the magnification chromatic aberration measuring unit 97 calculates a difference between the four corner positions of the red light and the blue light based on the four corner positions of the green light (step S16).
(11) The pass / fail judgment unit 98 judges whether or not the difference (pixel shift amount) between the four corners of red or blue is within a range of a predetermined reference value (process S17: pass / fail judgment procedure). If not, the projector 1 is determined to be defective. On the other hand, if it is determined that the chromatic aberration is within the range, the chromatic aberration of magnification is measured and acquired based on the calculated difference between the four corner positions (process S18: chromatic aberration of magnification measurement procedure). Finally, the data of the axial chromatic aberration and the chromatic aberration of magnification are stored in a hard disk or the like of the computer 90 in a state corresponding to the product number of the projector 1 to be inspected. Thus, the inspection of the projector 1 ends.
[0072]
[4. Effects of the embodiment)
According to the present embodiment, the following effects can be obtained.
(1) By performing the inspection using the projector inspection apparatus 10 in the above-described procedure, the axial chromatic aberration and the chromatic aberration of magnification of the projector 1 to be inspected can be easily and accurately inspected. Therefore, the quality of the projector 1 to be inspected can be accurately determined. Therefore, the projector 1 that enables high-quality image projection can be reliably provided on the market.
[0073]
(2) By adopting the 3CCD 81 as the image sensor, RGB images can be captured almost simultaneously at one time as compared with a case where each color light is captured using a color filter, thereby improving the efficiency of inspection. it can.
[0074]
(3) By arranging four 3-CCD cameras 81, inspection can be performed at a plurality of locations on the projected image, and the accuracy of the inspection can be improved.
[0075]
(4) Since the light beam emitted from the projection lens 46 of the projector 1 is reflected by the reflection device main body 721 and the reflected light is projected on the transmission screen, the size of the inspection device 10 can be reduced. In addition, since the reflection device main body 721 that reflects image light is moved, the amount of movement can be reduced as compared with the case of moving the transmissive screen, so that the inspection time is shortened and the size of the device is reduced, resulting in efficiency. Improvement can be achieved.
[0076]
(5) Since all the inspections are automatically performed by using the computer 90 or the like, the inspection efficiency can be improved.
[0077]
[5. Modification of Embodiment)
Note that the present invention is not limited to the above-described embodiment, but includes other configurations and the like that can achieve the object of the present invention, and includes the following modifications and the like.
For example, a three-CCD camera having three CCDs is employed as an imaging device, but the present invention is not limited to this, and a CCD camera having one CCD and a color filter may be employed. Also, the number of 3CCD cameras is not limited to the above four, and may be another number such as two, six, or nine.
[0078]
Further, the projector inspection device 10 is configured to reflect the image light on the reflection device main body 721 and then project the image light on the transmissive screen 71 to move the reflection device main body 721 forward and backward. A configuration may be adopted in which the image light is directly projected onto the transmission screen 71 and the transmission screen 71 is moved forward and backward without using the 721.
[0079]
In each of the above embodiments, a liquid crystal panel is used as the light modulation device. However, the present invention is not limited to this. For example, a reflection type light modulation device other than liquid crystal, such as a device using a micromirror, may be used.
In addition, the specific structure, shape, and the like at the time of carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.
[0080]
【The invention's effect】
According to the present invention, there is an effect that the optical characteristics of the projector can be accurately inspected and the quality of the projector can be accurately determined.
[Brief description of the drawings]
FIG. 1 is a perspective view of a projector according to an embodiment of the present invention as viewed from above.
FIG. 2 is a perspective view of the projector viewed from below.
FIG. 3 is a plan view schematically showing an optical unit constituting the projector.
FIG. 4 is a side view showing the projector inspection device according to the present invention.
FIG. 5 is a plan view showing the projector inspection device.
FIG. 6 is a view of a transmission screen constituting the projector inspection apparatus as viewed from the rear side.
FIG. 7 is a diagram schematically showing a control structure of the projector inspection device.
FIG. 8 is a block diagram showing functions of a computer constituting the projector inspection device.
FIG. 9 is a flowchart showing a procedure for inspecting the projector using the projector inspection apparatus.
FIG. 10 is a diagram showing a projection image projected on the transmission screen.
[Explanation of symbols]
1 Projector
10 Projector inspection equipment
44 Optical device
46 Projection lens (projection optical system)
50 Inspection unit body
50B installation stand
60 Projection unit body
70 screen unit (transmission screen device)
71 Transmission Screen
72 Reflection unit (reflection device)
80 Image detection device (imaging device)
81 3 CCD camera (image sensor)
82 Moving mechanism (imaging element moving mechanism)
90 Computer (image processing device)
92 Focus position adjustment unit
93 Movement amount acquisition unit
94 On-axis chromatic aberration measurement unit
95 Image sensor adjustment unit
96 Outer edge position acquisition unit
97 magnification chromatic aberration measurement unit
98 Pass / fail judgment section
100 Video capture board (image capture device)
416 Light source lamp (light source)
441 (441R, 441G, 441B) liquid crystal panel
722 Reflecting device moving mechanism (screen device moving mechanism)
X Projected image
Y Four corners (outer edge)

Claims (6)

Quality of a projector including a light source, an optical device that modulates a light beam emitted from the light source according to image information to form an optical image, and a projection optical system that enlarges and projects the optical image emitted from the optical device Projector inspection device for inspecting
An installation table on which the projector to be inspected is installed;
A transmission screen device that forms a projection image based on an optical image magnified and projected from the inspection object installed on the installation table;
A screen device moving mechanism that can move the transmission type screen device in the forward and backward directions with respect to the projection optical system,
An imaging device that is installed on the back side of the transmission screen device and includes an imaging element that captures a projection image projected on the transmission screen device,
An image capturing device that captures a projection image captured by the image sensor and converts the captured image into an image signal;
An image processing device that performs an arithmetic operation on an image based on the image signal captured by the image capturing device,
The image processing apparatus includes a focus position adjustment unit that performs drive control of the screen device moving mechanism so that the focus of the projection image captured by the imaging element matches.
For each of a plurality of color lights constituting the projection image, a movement amount acquisition unit for acquiring a movement amount from a reference position of the transmission screen device after focus adjustment by the focus position adjustment unit,
An axial chromatic aberration measuring unit that measures the axial chromatic aberration of the projected image based on the movement amount of each of the acquired color lights;
A projector inspection apparatus comprising: a quality judgment unit that judges the quality of a projector to be inspected based on the measured value of the axial chromatic aberration. The projector inspection device according to claim 1,
The projector inspection apparatus according to claim 1, wherein the imaging device includes a plurality of imaging elements that separate a projection image formed on the transmission screen device into a plurality of color lights. The projector inspection device according to claim 2,
The imaging device includes an imaging device moving mechanism that moves the plurality of imaging devices along a projection surface of the transmission screen device,
An image sensor adjusting unit that drives and controls the image sensor moving mechanism so as to image an outer peripheral end of a projection image formed on the transmission screen device, and moves the plurality of image sensors, respectively. When,
An outer edge position acquisition unit that acquires the position of each image sensor that has moved to a position corresponding to the outer edge of the projection image for each of a plurality of color lights;
A magnification chromatic aberration measurement unit that measures magnification chromatic aberration based on the position of each imaging element obtained for each of these color lights,
The projector inspection apparatus, wherein the pass / fail determination unit determines pass / fail of the projector to be inspected based on the measured value of the chromatic aberration of magnification. The projector inspection apparatus according to any one of claims 1 to 3,
The transmission screen device includes a reflection device that reflects an optical image enlarged and projected from the inspection target, and a transmission screen on which a projection image based on the optical image reflected by the reflection device is formed.
The projector inspection apparatus, wherein the screen device moving mechanism is configured to be able to move the reflection device in a forward / backward direction with respect to the projection optical system. Quality of a projector including a light source, an optical device that modulates a light beam emitted from the light source according to image information to form an optical image, and a projection optical system that enlarges and projects the optical image emitted from the optical device A projector inspection method for inspecting
A projection image forming procedure for enlarging and projecting an optical image from a projector to be inspected installed on an installation table to form a projection image on a screen device;
While the formed projection image is captured by the image sensor for each of the plurality of color lights, the transmission screen device is moved forward and backward with respect to the projection optical system to be adjusted so that the focus of the projection image for each color light matches. A screen device moving procedure to be moved;
A movement amount acquisition procedure for acquiring the movement amount from the reference position of the screen device for each color light,
An axial chromatic aberration measurement procedure for measuring the axial chromatic aberration of the projected image based on the acquired moving amounts of the respective color lights,
A quality inspection procedure for determining the quality of the projector to be inspected based on the measured value of the axial chromatic aberration. The projector inspection method according to claim 5,
An imaging element adjustment procedure of moving the plurality of imaging elements by an imaging element moving mechanism, so as to capture an outer peripheral end of a projection image formed on the transmission screen device in the projection image formation procedure;
An outer peripheral end position acquisition procedure for acquiring the moved position of each image sensor for each of the plurality of color lights,
A magnification chromatic aberration measurement procedure for measuring the magnification chromatic aberration of the projected image based on the position of each imaging element obtained for each of these color lights,
In the projector inspection method, the quality determination step determines the quality of the projector to be inspected based on the value of the chromatic aberration of magnification measured in the chromatic aberration of magnification measurement procedure.

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