Abstract: A projection display apparatus includes: a red imager; a green imager; a blue imager; a polarization adjusting element; a color combining unit; and a controller. A superimposed component light enters the polarization adjusting element together with the fourth color component light. The polarization adjusting element transmits the superimposed component light, whereas transmitting the fourth color component light by adjusting the polarization of the fourth color component light in accordance with switching between a low voltage applied state and a high voltage applied state. The controller controls re-orienting operation of applying a high voltage to the polarization adjusting element.

Abstract: An illumination apparatus includes multiple liquid crystal panels, a polarization-state adjusting element, and a cross dichroic prism. A green component light includes a central-wavelength component light, a short-wavelength component light, and a long-wavelength component light. The polarization-state adjusting element separately adjusts a polarization state of the central-wavelength component light and each of polarization states of the long-wavelength component light and the short-wavelength component light.

Abstract: A projection system includes a display apparatus comprising a plurality of tunable Fabry-Perot filters, each of the filters being configured for shifting between a state in which the filter transmits radiation in a bandwidth in the visible range of the electromagnetic spectrum and a state in which the filter transmits radiation in a bandwidth outside the visible range of the electromagnetic spectrum. An illuminator provides light to the plurality of Fabry-Perot filters. A control system receives image data and controls the display apparatus to project an image onto an associated display surface. The control system includes a modulator which provides wavelength modulation signals to the plurality of Fabry-Perot filters to modulate a color of pixels in the image and causes selected ones of the Fabry-Perot filters to shift into the bandwidth outside the visible range to modulate the brightness of pixels in the image.

Abstract: An illumination optical system includes a first compression system configured to compress a light flux on each of first and second sections, a second compression system configured to compress the light flux on the first section, a polarization converter arranged so that a section that contains a normal of the second polarization splitting surface and the optical axis becomes the second section, and configured to convert non-polarized light into linearly polarized light, a first lens array arranged in front of the polarization converter along an optical path, and a second lens array arranged between the first lens array and the polarization converter along the optical path. Both of the first lens array and the second lens array have no optical power on the second section.

Abstract: An image display apparatus includes an image display element configured to modulate incident light from a light source, a polarization splitting element that has characteristics of transmitting first polarized light and reflecting second polarized light different from the first polarized light and that is configured to synthesize image light from the image display element to be introduced into a projection optical system, and a phase difference plate that is disposed at a side of the projection optical system relative to the polarization splitting element. The phase difference plate has an optic axis in a direction different from a surface normal direction and an in-plane direction of the phase difference plate.

Abstract: A polarization element includes: a substrate; a plurality of convex line sections on one surface of the substrate and forming stripes in a plan view; and a multilayer thin line provided to each convex line section and extending along the convex line sections, wherein the multilayer thin line has a lower layer on the convex line section, and an upper layer stacked on the lower layer, the lower layer and the upper layer each have a first thin line on one side surface in a direction along a shorter dimension of the convex line section, and a second thin line on the other side surface, the materials of the lower layer first thin line and the upper layer first thin line are different from each other, and the materials of the lower layer second thin line and the upper layer second thin line are different from each other.

Abstract: An illuminating device includes: light source (101); light guiding means (102) where light from light (101) is supplied to one end surface, and light incident from the one end surface is propagated inside to exit from the other end surface; illuminating optical systems (103 to 107) that form an optical image formed on the other end surface of light guiding means (102) on display element (22); reflective polarizing plate (109) that is located between illuminating optical systems (103 to 107) and display element (12), and transmits first polarized light while reflecting second polarized light whose polarized state is different from the first polarized light toward illuminating optical systems (103 to 107); phase plate (108) located between light guiding means (102) and reflective polarizing plate (109); and reflecting means (21) that is located on a side opposite the one end surface of light guiding means (102), and reflects, among lights by reflective polarizing plate (109), light incident via phase plate (108

Abstract: Disclosed is a projection image display apparatus which includes a light source; and an illumination optics including a phase difference plate. The illumination optics is configured to form an image on a liquid crystal panel with light beams emitted from the light source. The phase difference plate has a deviation in viewing angle characteristics and is arranged to yield a desirable phase difference for a light beam directed in a direction of high intensity among incident light beams distributed at various angles.

Abstract: Provided is an illuminating device that includes: first light guiding means (3) where light incident from one end surface is propagated inside to exit from the other end surface; illuminating optical system (1) that spatially separates a luminous flux from the other end surface of first light guiding means (3) into a plurality of luminous fluxes, and forms an optical image formed on the other end surface of first light guiding means (3) on display element (12); reflective polarizing plate (11) that is located between illuminating optical system (1) and display element (12), and transmits first polarized light while reflecting second polarized light different that is in polarized state from the first polarized light toward illuminating optical system (1); reflecting element (7) that is disposed at a position where the plurality of luminous fluxes are spatially separated, and that includes transmission regions through which the plurality of luminous fluxes are transmitted, and a reflecting film formed in a regi

Abstract: A laser projector includes a green laser, a two-wavelength laser, a PBS, a collimator lens, a two-axis galvanometer mirror, a group of lenses, and a screen. The green laser emits a green laser beam. The two-wavelength laser emits red and blue laser beams. The PBS is provided at the position where respective optical paths of laser beams emitted from respective lasers cross each other to cause these optical paths to coincide with each other.

Abstract: A laser projection system is provided comprising a light source, a phase retarding element, and a beam scanning element. The light source comprises at least one frequency-converted laser source comprising a wavelength-tunable laser diode and a wavelength conversion device. The phase retarding element is configured to resolve the polarization of a frequency-converted laser beam into two orthogonal linearly polarized components such that one component of polarization is phase delayed relative to the other. Frequency-converted laser beam polarization in the 2D image frame is a function of the degree to which the respective components of polarization are delayed relative to each other and varies with wavelength variations in the output of the wavelength-tunable laser diode. Polarization variations of the frequency-converted laser beam in the 2D image frame are sufficient to scramble image speckle patterns across the 2D image frame.

Abstract: A projection type display apparatus includes: a reflective polarizing plate for each color light which transmits each of R light, G light and B light therethrough, allows each transmitted light to enter a corresponding reflective liquid crystal panel for each color light, and reflects image light of each color which has been subjected to light modulation in accordance with an image signal of each corresponding color light by the reflective liquid crystal panel for each color light; an absorption type polarizing plate for R and G lights and a reflection type polarizing plate for B light, each of which removes an unnecessary polarized component from the image light of each color reflected by the reflective polarizing plate for each color light; a color combination optical system which subjects the image light of each color transmitted through the transmission type polarizing plate for each color light to color combination.

Abstract: A dual TIR prism has an input prism, a wedge prism, an output prism, and a reflective polarizer. The dual TIR prism is configured to receive an optical beam at an entrance surface, to pass the first polarization direction of the received optical beam from a second exit surface, and to output the second polarization direction of the received optical beam from a first exit surface of the input prism.

Abstract: A light source device has: a light source unit including solid-state light sources emitting blue-color light and a condensing lens; a dichroic mirror polarization separating color light into first and second polarization components; a fluorescence emission plate excited with the first polarization component, emitting fluorescence of green and red components to enter the dichroic mirror; a first retardation plate converting the second polarization component to a circularly polarized light; and a reflection plate reflecting a light passed through the first retardation plate to reenter the same. The color lights from the fluorescence emission plate and the first retardation plate are combined at the dichroic mirror. A second retardation plate converts the polarization direction of the light from the light source unit, so as to control the ratio of p-polarization and s-polarization components. Lights from solid-state light sources are condensed efficiently and a high spectrum-utilization factor is obtained.

Abstract: In addition to reflective light modulation devices, reflective polarization plates, a color combining optical device, and support bodies, a projector is provided with connection members fixed to the color combining optical device and for supporting the support bodies. Support positions of the support body by the connection members are disposed on the opposite side to the disposition position of the reflective light modulation device with respect to a plane including a polarization split surface of the reflective polarization plate.

Abstract: An image projecting unit of a projector includes a light source; a polarization control element which controls a polarization direction of light emitted from the light source; and a projecting unit which projects the image light that passed through the optical modulation element. The control unit detects a deterioration state of the polarization control element based on the projected image which is taken by an image-taking unit when a test image representing a single color throughout a screen is projected.

Abstract: A projector includes: a light source; a polarization conversion element array having an entrance surface on which an effective entrance area and an ineffective entrance area are disposed to form stripes; a modulation device adapted to modulate a linearly polarized light beam emitted from the polarization conversion element array in accordance with an image signal; a projection device adapted to project the modulated light beam; a first light shielding section, a part of the entrance surface being provided with the first light shielding section adapted to shield a part of the incident light beam to the effective entrance area; and a first opening section, the first opening section being another area of the entrance surface than the part provided with the first light shielding section, at least a part of the first opening section reaches an end of the entrance surface.

Abstract: A wide color gamut projector having a plurality of dichroic prisms configured to split a light beam into six primary color components and direct each of the six primary color components to separate digital micromirror devices is disclosed. The projector further comprises a translucent rotatable drum having different polarization sections, wherein the light beam is capable of being passed orthogonally through a wall of the drum.

Abstract: A projection apparatus including an illumination module, a display panel, and a projection lens module is provided. The illumination module includes a light source assembly including a light guide plate, a light source, a reflector, and a reflective polarizer, and a polarized beam splitter (PBS). The light guide plate has a light emitting surface, a bottom surface opposite to the light emitting surface, and a light incident surface connected between the light emitting surface and the bottom surface. The light source, the reflector, and the reflective polarizer are faced to the light incident surface, the bottom surface, and the light emitting surface respectively. The PBS is disposed beside the reflective polarizer away from the light guide plate. The display panel and the light source assembly are respectively located at two adjacent sides of the PBS. The projection lens module is disposed beside the PBS away from the display panel.

Abstract: A light source device includes a phosphor layer formed on a base, and an excitation light source exciting the phosphor. A dichroic mirror is arranged between the phosphor layer and the excitation light source and inclined with respect to a propagation direction of excitation light from the excitation light source. An incident region of the excitation light and an exiting region of fluorescence emitted from the phosphor belong to a space on the same side with respect to the surface with the phosphor layer disposed. In a dominant wavelength of the excitation light, the dichroic mirror has a spectral characteristic of transmitting 50% or more of light of a p-polarized component and reflecting 50% or more of light of a s-polarized component. Fluorescence emitted from the phosphor layer can be extracted highly efficiently and propagated by a compact and simple optical system.

Abstract: A method and apparatus for bitstream modulation of an infrared light source used by an optical sensor in a stereoscopic projection system, combined with a bitstream filter on the receiver electronics.

Abstract: A polarization image capturing section 103 obtains a first polarization image containing polarization information. A polarization information obtaining section 104 obtains first polarization information from the first polarization image. An illumination control section 102 changes an illumination section 101 and again obtains a second polarization image by means of the polarization image capturing section 103. The polarization information obtaining section 104 obtains second polarization information from the second polarization image. A light source dependency estimation section 105 obtains light source dependency from the first and second polarization information obtained from the first and second polarization images. An area dividing section 106 performs an area division by using the polarization information and light source dependency information.

Abstract: A stereoscopic image projection system using a circular polarization filter module is provided. Even though this system uses a single projector, it allows left and right images to have different polarization directions using the circular polarization filter module, thereby reducing crosstalk compared to an LCD-shutter-based system.

Abstract: Method to display an image using four or more primaries having different spectral distributions that are distributed into three groups of primaries, wherein, in a visual color space, all primaries belonging to the same group have the same visual color and are metamehc. Each image being got from a combination of three primary images and each primary image being associated with each visual color of a group, the different primaries of each group are spatially or sequentially distributed over the primary image associated with this group, then allowing an efficient anti-copy protection based on metamerization of images, without any supplemental video processing.

Abstract: A stereo 3D projector with the ability to provide the native lumen output of the projector when not in 3D mode. This is accomplished by using two rotating polarizing filters at least partially overlapping, each with at least two or more segments, some of which are fully transparent and at least some of which are polarized linearly or circularly.

Abstract: A device for a vehicle that includes an at least partially transparent member operatively connected to the vehicle, the at least partially transparent member having a first side and a second side. A projector emits electromagnetic radiation projecting an image on or in the at least partially transparent member. A first polarizer is positioned on the first side of the transparent member such that the electromagnetic radiation goes through the first polarizer. A second polarizer is positioned on the second side of the at least partially transparent member. The first polarizer and the second polarizer are oriented such that the image is visible from the first side of the at least partially transparent member and not visible from the second side of the at least partially transparent member. The second polarizer may have a second polarization axis that is substantially orthogonal to a first polarization axis of the first polarizer.

Abstract: A projection device with an illumination adjustment function includes a polarization beam splitter (PBS), a display, a light source, a lens module, a power supply unit, a light detection unit and a power controller. The light source emits light to the PBS. The lens module projects the images to be displayed by the display. The power supply unit supplies power for the light source. The light detection unit acquires a digital value of a portion of the light transmitted from the PBS, and compares the digital value with a predetermined digital value to generate a control signal. The power controller adjusts power from the power supply unit to the light source according the control signal until the digital value matches the predetermined digital value of the light from the light source.

Abstract: Polarization preserving projection screens provide optimum polarization preservation for 3D viewing. The projection screens additionally provide improved light control for enhanced brightness, uniformity, and contrast for both 2D and 3D systems. Generally, the disclosed method for providing a projection screen comprises stripping an optically functional material from a carrier substrate, thus creating engineered particles from the optically functional material. The engineered particles may then be deposited on a second substrate to create a substantially homogeneous optical appearance of the projection screen.

Abstract: An image projection device performing pixel shift in synchronization with sequential updating of image data is disclosed that is able to start and stop pixel shift operations within a period of updating the image frames while maintaining brightness of the image. The image projection device has an intermediate image formation optical system including a light valve able to update an image frame in a line-sequential manner, a pixel shift unit to shift the light path of a light beam from the light valve so as to shift a position of an image formed on the light valve, and an intermediate image formation unit arranged on the light path between the light valve and the pixel shift unit for forming an intermediate image of the image on the light valve at a position of the pixel shift unit.

Abstract: A method and apparatus for extracting synchronization information at the output of a projection apparatus, without modifying its rotating color segmented filter wheel or drive electronics. Three photodiodes, each with a different principle color filter, is placed at the projector output to detect output of the different colors in the filter wheel. An exclusive OR circuit is used to detect white light passing through the filter wheel.

Abstract: A 3D stereographic projection apparatus comprises an input for receiving stereographic image data that includes sync signals corresponding to image streams in the image data. A digital light projector projects the stereographic image data. A motor driven rotating filter has a marker disposed thereon positioned in the path of the projected stereographic image data. The motor driven rotating filter separately polarizes the image streams in the stereographic image data. A motor drive circuit, coupled to the input, receives the sync signals and synchronizes a rotation of the filter with the sync signals. A tach sensor, comprising a light transmitter and detector coupled to the rotating filter, detects the marker and outputs marker signals indicating that the marker is detected.

Abstract: Disclosed are a display apparatus and a light control method thereof, in which the display apparatus including a display panel, a light source unit, an illumination unit to illuminate the display panel with light emitted from the light source unit, and a projection unit to project the light from the display panel in a predetermined direction includes: a light sensor which is provided between the light source unit and the illumination unit; and a light controller which corrects brightness of light sensed by the light sensor on the basis of reflective characteristics of the display panel. With this configuration, the quantity of light is prevented from decreasing so as to prevent the brightness of an image from decreasing.

Abstract: A light source apparatus includes: a light source that emits blue component light; a polarization adjuster that adjusts a polarization state of the blue component light emitted from the light source; a separation optical element that separates the blue component light emitted from the light source into a first optical path and a second optical path according to the polarization state adjusted by the polarization adjuster, the first optical path being for using the blue component light as excitation light, the second optical path being for using the blue component light as reference image light; a luminous body provided on the first optical path and that emits reference image light in response to the excitation light; and a combine optical element that combines the first optical path and the second optical path into a single optical path.

Abstract: A polarization conversion element is equipped with an element main body having a light incident surface and a light emission surface that are generally in parallel with each other, and a phase difference plate bonded to the light emission surface of the element main body. The element main body includes a plurality of light-transmissive substrates that are sequentially bonded at a predetermined angle with respect to the light emission surface, polarization separating films and reflection films that are alternately provided between the plurality of light-transmissive substrates, and adhesive layers formed between the plurality of light-transmissive substrates, respectively. The adhesive layers are each formed from ultraviolet light curing adhesive to a thickness between 5 ?m and 10 ?m.

Abstract: Provided is an electronic image display and control system comprising in various embodiments a microdisplay video projector that projects a high quality color image from a non-CRT image source onto a diffused but transmissive optical projection screen that is optically coupled with and viewable through a biocular adapted to this purpose. Systems are disclosed that are adapted to be mechanically coupled with a user to prevent relative movement between the biocular and the user, for instance in tactical applications. Closed-loop control electronics are provided for automatically controlling the brightness and chromaticity of the image.

Abstract: A light source apparatus includes: a light source; a reflection rotary body; an optical path changing element; and a polarization controller. The polarization controller controls polarization of the first color component light to a different polarization by means of transmission of the first color component light emitted from the light source and by means of transmission of the first color component light reflected by the reflection rotary body. The optical path changing element guides the first color component light reflected by the reflection rotary body, in a direction different from a direction of the first color component light emitted from the light source, in accordance with the polarization of the first color component light modulated by the polarization controller.

Abstract: A lighting device, including a first light source emitting light of a first wavelength; a second light source close to the first source, emitting light of a second wavelength in almost a same direction as that of the first source; a third light source located emitting light of a third wavelength in a direction different from that of the first and second sources; a coupling optical system coupling light from the first and second sources; another coupling optical system coupling light from the third source; and a light path synthesizer synthesizing a light path of light from the first, second and third sources, wherein the light path synthesizer includes a first surface reflecting light from the first source and transmitting light from the second and third sources and a second surface unparallel with the first surface, reflecting light from the second source and transmitting light from the third source.

Abstract: A speckle reducing device includes: a polarization splitter element with a polarization splitter portion that splits incident light into first and second light containing a first and a second component respectively, which outputs the first and the second light along different directions; a first reflecting member that reflects the first light to reenter the polarization splitter element; a first conversion member disposed between the first reflecting member and the polarization splitter element, which converts the first light to third light containing the second component; a second reflecting member that reflects the third light to reenter the polarization splitter element; and a second conversion member disposed between the second reflecting member and the polarization splitter element, which converts the third light to fourth light containing the first component, wherein: the polarization splitter element outputs the second and the fourth light along one direction.

Abstract: A polarized light source comprises a light emitting source and a polarization conversion device. The polarization conversion device comprises a fixing device (107), and a transparent moveable carrier (104) having motion state with respect to the fixing device (107) and provided with light wavelength conversion material (103). The polarization conversion device further comprises a stationary polarization beam splitter (101) close to the moveable carrier for transmitting a portion of excited light from the light wavelength conversion material (103) to provide a polarized emitted light and reflecting the other portion back to the light wavelength conversion material (103). A filter (102) for reflecting the excited light and transmitting the light from the light emitting source can be disposed at the side of the moveable carrier opposite to the polarization beam splitter (101).

Abstract: An image display apparatus includes an illumination optical system that includes first and second beam splitting units, a first polarization conversion element, third and fourth beam splitting units, a second polarization conversion element, a first beam combining unit configured to combine a plurality of first polarized light beams with a plurality of second polarized light beams, a third polarization conversion element configured to convert a plurality of combined light beams into a plurality of polarized light beams, and a condensing unit configured to superimpose the plurality of polarized light beams onto the image display element, wherein each of the first and third beam splitting units includes a cylinder lens array.

Abstract: An optical system unit having a light smoothing unit for emitting a light beam which is substantially parallel to an optical axis and a projector including the optical system unit are provided. The optical system unit includes a light source-side optical system, a display device for forming an image by reflected light and a projection-side optical system, whereby a light beam emitted from the light source unit is shone on to the display device via the light source-side optical system, an image is formed by the display device, and the image so formed is projected on to a screen via the projection-side optical system. The light smoothing unit of the light source-side optical system is such that at least one side of sides other than an incident side and an emitting side is disposed obliquely relative to a side which the at least one side confronts so that an area of the emitting side becomes larger than an area of the incident side.

Abstract: A display device includes: a light source section; an optical modulator modulating light from the light source section based on a picture signal, to emit modulated light as picture light; a direct-view display section performing direct-view display based on the picture light; a projection optical system performing projection display on a projection screen based on the picture light; an optical member allowing the picture light from the optical modulator to travel toward at least one of the direct-view display section and the projection optical system; and a switching section performing control of traveling direction of the picture light on the optical member, to switch between two or more display modes which are selected, to include a two-way display mode, from a group consisting of a direct-view display mode, a projection display mode, and the two-way display mode.

Abstract: A projector system includes a light source module, a light guiding plate, a polarizing beam splitter (PBS) module and a projection lens module. The light source unit includes a red-color light source, a green-color light source and a blue-color light source respectively for emitting red, green and blue light. The light guiding plate optically combines light emitted from the red-color light source, the green-color light source and the blue-color light source. The PBS module is positioned opposite to the light output surface of the light guiding plate and is configured for splitting the combined light into s-polarization light and p-polarization light, reflecting the s-polarization light and converting the reflected s-polarization light into p-polarization light, modulating and outputting the converted p-polarization light using a display information signal. The projection lens module projects light with information onto a screen.

Abstract: In a projection type display apparatus using plural light sources, an optical unit including plural light sources, a first collimator lens, an optical coupling lens, an image display element and a projection lens is formed, and in an optical path extending from the light sources to the projection lens, light is condensed only once on the image display element, thereby minimizing the number of optical parts used and shortening the length of the optical path from the plural light sources up to the projection lens to attain the reduction in size of the projection type display apparatus or the optical unit. In this way it is possible to provide a projection type display apparatus or an optical unit each capable of attaining the reduction of cost by minimizing the number of optical parts used and capable of attaining a high luminance by irradiating the image display element with the light emitted from the light sources without leakage of the light.

Abstract: Etendue maintaining polarization switching occurs, according to various embodiments, with a mirror that quickly transitions between two positions. Light having uniform polarization is transmitted to the mirror. Light reflected off of the mirror in one of the two positions has its polarization changed, whereas light reflected off of the mirror in the other of the two positions has its polarization maintained. Thereafter, the polarization-changed light and the polarization-maintained light easily may be recombined in an entendue-maintaining manner. Because the recombined light includes two different polarization states, stereoscopic images may be generated.

Abstract: An image forming system is described that includes a light source that provides a light beam and an anamorphic refractive optical element. A first outer surface of the anamorphic element faces the light source and includes a toric surface. The light beam is incident upon the first outer face and then an incident surface of the anamorphic element. The anamorphic element directs the light beam to an image forming device. An illumination system is also described where an anamorphic element includes a toric surface and a facet surface.

Abstract: A projection type display apparatus includes: a light source section including at least one light source for emitting coherent light; an image light generating section for modulating the light emitted from the light source section so as to generate image light; a projection section for projecting the image light; and a depolarization element for transmitting the incident light in a state that a polarization state of at least a part of the light is changed, the depolarization being provided on an optical path of the light emitted from the light source section, wherein a plurality of unit regions having a particular shape are aligned in the depolarization element.

Abstract: A phase plate includes a transparent substrate and a periodic structure formed on a substrate surface of the transparent substrate. The phase plate is configured to provide light having a predetermined design wavelength that vertically enters the substrate surface with a phase difference from ¼ wavelength to ¾ wavelength. The periodic structure is configured to reduce a volume occupation rate with increasing distance from the transparent substrate, and the periodic structure has a height of at least 200 nm. An angle between a first direction in which a center of a width of a unit periodic structure at a position closest to the substrate surface is connected with a center of a width of a unit periodic structure at a position farthest from the substrate surface and a normal direction of the substrate surface is from 5 degrees to 30 degrees.

Abstract: An optical projection engine device uses a symmetrical wire grid polarizing beam splitter (PBS) that splits incident illumination to a symmetrical pair of polarized light beams in two orthogonal polarization states, one by reflection and the other by transmission, for illuminating a pair of reflective modulation imagers respectively. In identical geometric configuration, the two synchronized reflective modulation imagers polarization modulate polarized light beams as received, and reflect them back towards the PBS, which through transmission and reflection respectively, combines and projects two modulated light beams through a projection lens system to form a pair of spatially overlapped illumination images of aligned pixels with the same image in two orthogonal polarization states on a projection screen. The device jointly provides improvement optical efficiency and expanded function to three dimensional stereoscopic displays.

Abstract: A cooling device which prevents ambient persons from being exposed to an unpleasant feeling as much as possible by properly controlling an exhausting direction of the air which is used for cooling and exhausted from a chassis and an image projection apparatus having the cooling device are obtained. The cooing device cools first and second members to be cooled provided in the chassis, has first and second exhaust fans for guiding winds which have cooled the respective first and second members to an outside of the chassis, and is characterized in that the first and second exhaust fans are arranged so as to face the same surface of the chassis and the winds exhausted from the first and second exhaust fans are mixed.