JP2012037717A - Image display device and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device having a simple structure that removes the dirt on the device.SOLUTION: An image display device of the present invention includes: a display part that displays an image; a photocatalyst layer that is formed in front of the display part; and a light-emitting part that emits illumination light capable of illuminating the photocatalyst layer through the display part. The light-emitting part has a function of photoactivating the photocatalyst layer by illuminating the photocatalyst layer, and a function of illuminating the display part during the image display on the display part.

Description

  The present invention relates to an image display device and an imaging device that display an image.

  In an imaging device such as a digital camera, it functions as an image display device that displays images captured before shooting (through images) and images obtained by shooting, and a viewfinder (electronic viewfinder) that displays through images under shooting. An image display device is used.

  By the way, the above-described imaging apparatus has a drawback that organic substances, dust, dust, etc. floating inside adhere to the surfaces of the image display apparatus and the imaging element, and the surfaces become dirty. As a method for preventing such drawbacks, for example, a photocatalytic substance is coated on the surface of an optical low-pass filter provided in an image pickup device, and the surface of the optical low-pass filter is irradiated with ultraviolet light to photoactivate the photocatalytic substance (patent) In addition to this, a method of vibrating an optical low-pass filter (see Patent Document 2) and the like have been proposed.

JP 2009-17273 A JP 2008-122792 A

  However, when the method described in Patent Document 1 is applied to an image display device such as an electronic viewfinder, it is necessary to newly incorporate a light source that emits ultraviolet light. In the case of Patent Document 2, since the photoactive substance is photoactivated by the ultraviolet light included in the incident light from the outside, it can be applied when the incident light from the outside such as an electronic viewfinder is not required. In this case as well, it is necessary to newly incorporate a light source for irradiating ultraviolet light.

  An object of the present invention is to provide an image display device and an imaging device that can easily remove dirt adhering to an image display device without adding a new configuration.

  In order to solve the above-described problems, an image display device of the present invention illuminates the photocatalyst layer via a display unit that displays an image, a photocatalyst layer formed on the front surface of the display unit, and the display unit. A light emitting unit that emits illumination light, and the light emitting unit illuminates the photocatalyst layer to photoactivate the photocatalyst layer, and the display unit is configured to display the image on the display unit. It has the function to illuminate.

  Moreover, it is preferable to provide a structure for enhancing the directivity of illumination light from the light emitting unit between the light emitting unit and the display unit.

  In this case, the structure for improving the directivity of the illumination light from the light emitting unit is a micro lens array structure in which micro lenses are two-dimensionally arranged. Further, the structure for enhancing the directivity of the illumination light from the light emitting section is a multilayer film structure and a structure for resonantly amplifying light in a specific wavelength region.

  In addition, light in a wavelength range that can accumulate the illumination light from the light emitting unit and becomes visible light between the display unit and the light emitting unit or between the display unit and the photocatalytic layer. It is preferable to have a thin film layer made of a phosphorescent material that transmits light.

  In addition, it is preferable that the display unit includes a liquid crystal panel, and the light emitting unit includes a backlight that illuminates the liquid crystal panel from the back side.

  Furthermore, it is preferable that the said light emission part consists of either an inorganic LED element or an organic LED element. The photocatalyst layer is preferably a thin film layer using titanium oxide as a photocatalyst material, and the light emitting section preferably emits illumination light having a wavelength range of 380 nm or less.

  The image pickup apparatus of the present invention is characterized in that the above-described image display apparatus is incorporated as a finder. In this case, it is preferable that the image display device incorporated as the finder is arranged so that the front surface of the image display device is substantially parallel to a plane including a vertical direction with respect to the imaging device main body.

  According to the present invention, it is possible to remove dirt attached to the image display device with a simple configuration.

It is a figure which shows the outline of a structure of an electronic camera. It is sectional drawing which shows the outline of LCD using this invention. It is sectional drawing which shows the outline of LCD provided with the micro lens array structure. It is sectional drawing which shows the outline of LCD provided with the optical cavity structure. It is sectional drawing which shows the outline of LCD provided with the luminous layer. It is a figure which shows the outline of a structure of the electronic camera provided with the optical finder.

  FIG. 1 schematically illustrates an electronic camera 10 as an example of an imaging apparatus according to the present embodiment. In FIG. 1, only the main part of the electronic camera 10 is shown in order to eliminate the complexity of the figure.

  The electronic camera 10 includes a lens unit 11 and a camera body 12 to / from which the lens unit 11 is attached / detached. Each of the lens unit 11 and the camera body 12 is provided with a pair of mounts 13 and 14 having a male-female relationship. When the lens unit 11 is attached to the camera body 12, the mount 13 provided on the lens unit 11 is coupled to the mount 14 of the camera body 12 by a bayonet mechanism or the like. Each of the mounts 13 and 14 is provided with an electrical contact. When the lens unit 11 is mounted on the camera body 12, the electrical contacts provided on the mounts 13 and 14 come into contact with each other, and the electrical connection between them is established. It should be noted that the electrical connection between these mounts 13 and 14 electrically connects a later-described lens microcomputer 26 and a controller 35 provided in the camera body 12, and executes transmission / reception of various signals between them. .

  In the present embodiment, an example of a so-called single-lens reflex electronic camera 10 in which the lens unit 11 is detachably attached to the camera body 12 is taken, but the present invention is not limited to this, and the lens unit 11 is not limited to the camera body 12. The so-called compact type electronic camera 10 may be provided.

  The lens unit 11 includes an imaging optical system 21, a zoom encoder 22, a lens driving unit 23, a diaphragm 24, a diaphragm driving unit 25, a lens microcomputer 26, and the like. The zoom encoder 22, the lens driving unit 23, and the aperture driving unit 25 are each controlled by a lens microcomputer 26.

  The imaging optical system 21 includes a plurality of lenses such as a zoom lens 21a and a focus lens 21b. The zoom lens 21a is a lens for adjusting the focal length, and can be moved in the direction of the optical axis L1 in accordance with, for example, the operation of the zoom ring by the user. The zoom encoder 21a is attached to the zoom lens 21a and detects the position of the zoom lens 21a in the direction of the optical axis L1. The focus lens 21b is a lens for adjusting the in-focus position, and can be moved in the direction of the optical axis L1. The lens driving unit 23 drives the focus lens 21b in the direction of the optical axis L1. A distance encoder for detecting a position in the optical axis L1 direction is attached to the focus lens 21b. Detection signals from the zoom encoder 22 and the distance encoder are output to the lens microcomputer 26. The lens microcomputer 26 receives these detection signals and calculates a shooting distance and a focal length at the time of shooting. Values such as the calculated shooting distance and focal length are output to the camera body 12. Although the zoom lens 21a can be moved in the direction of the optical axis L1 by the operation of the zoom ring by the user, the zoom lens 21a is not limited to this, and may be moved in the direction of the optical axis L1 by the lens driving unit 23.

  The diaphragm 24 adjusts the amount of light incident on the camera body 12 by opening and closing the diaphragm blades. The diaphragm drive unit 25 controls the aperture of the diaphragm 24. The lens microcomputer 26 communicates with the camera body 12 via the electrical contacts of the mounts 13 and 14 and executes various controls in the lens unit 11. The lens microcomputer 26 transmits lens data recorded in a ROM (not shown) to the camera body 12.

  Note that the lens unit 11 shown in FIG. 1 is merely an example of a configuration of a general zoom lens unit. Therefore, in addition to the lens unit 11 described above, for example, a lens unit that does not include a lens microcomputer or a lens unit of a single focus lens can be attached to the camera body 12.

  Next, the configuration of the camera body 12 will be described. The camera body 12 includes a mechanical shutter 31, an image sensor 32, an image display device 33, an electronic viewfinder 34, a controller 35, and the like. In FIG. 1, an electrical configuration incorporated in the camera body 12 and a configuration of operation members such as a release button are omitted.

  The mechanical shutter 31 and the image pickup device 32 are arranged on the optical axis L1 of the image pickup optical system 21 provided in the lens unit 11 in the order of the mechanical shutter 31 and the image pickup device 32 from the lens unit 11 side. For example, a focal plane shutter is used as the mechanical shutter 31. For example, a CCD image sensor or a CMOS image sensor is used as the image sensor 32.

  For example, when the electronic camera 10 enters a shooting standby state, the mechanical shutter 31 is opened, and subject light captured via the imaging optical system 21 is irradiated onto the imaging element 32. In this photographing standby state, the image sensor 32 outputs an image signal based on the received subject light at predetermined time intervals. The image signal output from the image sensor 32 at predetermined time intervals is an image signal that is the basis of the through image. As the release button is fully pressed, the mechanical shutter 31 is temporarily shielded. When the mechanical shutter 31 is shielded, a reset process is performed on the image sensor 32. Thereafter, the mechanical shutter 31 is opened, and when the time based on the set shutter speed has elapsed, the mechanical shutter 31 is shielded again. At this time, the image sensor 32 outputs an image signal based on the subject light received during the period (exposure time) when the mechanical shutter 31 is open. Note that the image signal output from the image sensor 32 at this time is a recording image signal obtained at the time of shooting.

  In the present embodiment, the case where the mechanical shutter 31 is used has been described. However, the present invention is not limited to this, and an electronic shutter is used instead of the mechanical shutter 31 or the mechanical shutter 31 and the electronic shutter are used in combination. It is also possible to do.

  The image display device 33 displays an image (through image or the like) based on an image signal output from the image sensor 32, and also displays a setting image when setting the electronic camera 10. As the image display device 33, for example, a liquid crystal display device (LCD) is used.

  The electronic viewfinder 34 includes an image display device 41 and an eyepiece lens 42. The image display device 41 and the eyepiece 42 constituting the electronic viewfinder 34 are arranged so that the optical axis L2 of the electronic viewfinder 34 is parallel to the optical axis L1 of the imaging optical system 21. At this time, the front surface (display surface) of the image display device 41 is disposed so as to be orthogonal to the optical axis L <b> 2 of the electronic viewfinder 34. By holding in this arrangement state, it is possible to prevent dust and dust having a size that cannot remove dirt due to photoactivity of the photocatalyst layer 54 described later from adhering to the front surface of the image display device 41.

  The electronic viewfinder 34 has been described with respect to the case where the optical axis L2 is arranged so as to be parallel to the optical axis L1 of the imaging optical system 21. However, the electronic viewfinder 34 is not limited to this. It is also possible to arrange the electronic viewfinder 34 so that the optical axis L2 of the finder 34 is in a state (symbol L2 ′) indicated by a dotted line that is inclined clockwise by an angle θ from the state indicated by the alternate long and short dash line. In this case, the upper end of the front surface of the image display device 41 is on the back side of the camera body 12 (right side in the figure), and the lower end of the front surface of the display device 41 is on the front side of the camera body 12 (left side in the figure). Each is in an inclined state. Even in such an arrangement state, the above-described dust or dust can be prevented from adhering to the front surface of the image display device 41.

  The image display device 41 displays an image (through image) based on an image signal output at predetermined intervals from the image sensor 32 in a shooting standby state. In accordance with this display, for example, values relating to exposure conditions (exposure values, etc.), focus areas, and the like are superimposed and displayed. As the image display device 41, an LCD is used similarly to the image display device 31. The LCD used as the image display device 31 may be an LCD having a lower resolution than the LCD used as the image display device 41. An image displayed by the image display device 41 is observed through the eyepiece lens 42. In FIG. 1, reference numeral 43 denotes a finder window. The image display device 41 will be described by taking an LCD as an example. However, the image display device 41 is not limited to this, and may be another image display device such as an EL panel.

  The controller 35 comprehensively controls the mechanical shutter 31, the image sensor 32, the image display device 33, the electronic viewfinder 34, and the like. For example, at the time of imaging, the controller 35 performs image processing on the image signal in addition to executing AE processing and AF processing using the image signal output from the imaging element 32. The image processing shown here includes white balance processing, interpolation processing, gradation conversion processing, luminance enhancement processing, and the like. In the imaging standby state, image processing is performed on the image signal output from the image sensor, and then the image of the image display device 33 and the electronic viewfinder 34 is processed on the image signal that has been subjected to image processing. Resolution conversion processing is executed so that the resolution corresponds to each of the display devices 41, and is output to the image display device 33 and the image display device 41 of the electronic viewfinder 34. As a result, through images corresponding to the respective resolutions are displayed on the image display device 33 and the image display device 41 of the electronic viewfinder 34.

  Next, the configuration of the image display device 41 incorporated as the electronic viewfinder 34 will be described. As described above, an LCD is used as the image display device 41. Hereinafter, the LCD used as the image display device 41 will be described with reference numeral 51. As shown in FIG. 2, the LCD 51 includes a liquid crystal panel 52 and a light source (backlight) 53. The liquid crystal panel 52 is, for example, a transmissive liquid crystal panel, and includes a plurality of pixels on which red, green, and blue filters are formed. A voltage is applied to the liquid crystal panel 52 by an LCD drive circuit (not shown) in accordance with a drive signal from the controller 35, and an image corresponding to an image signal input through the LCD drive circuit is generated. At this time, the controller 35 performs matrix conversion on the color information of the image signal to be displayed, and adapts it to the color gamut based on the color characteristics of the liquid crystal panel 52. As a result, the liquid crystal panel 52 realizes a function as a display element by the illumination light emitted from the light source 53 and displays an image (through image) based on the image signal output from the imaging element 32 so as to be observable. Note that the value of the voltage applied to the liquid crystal panel 52 is set corresponding to a reference voltage applied to the light source 51 described later.

  As the light source 53, for example, an organic LED element or an inorganic LED element is used. As the light source 53, an organic EL element or an inorganic EL element may be used in addition to the LED element described above. Illumination light emitted from the light source 53 is applied to the liquid crystal panel 52. The light transmitted through the liquid crystal panel 52 is applied to the photocatalyst layer 54.

  A thin film layer 54 made of a photocatalytic material is provided on the front surface of the liquid crystal panel 52 described above. Hereinafter, the thin film layer 54 made of the photocatalytic substance is referred to as a photocatalytic layer 54. The photocatalytic layer 54 is formed on the surface of the liquid crystal panel 52 by using a thin film coating technique such as dip coating or spin coating, a deposition technique such as PVD or CVD, or a technique such as sputtering. In addition, it is preferable that the photocatalyst layer 54 is formed in the range whose thickness is 100-200 nm.

The photocatalyst layer 54 is a material layer that promotes a chemical reaction around the photocatalyst layer 54 when irradiated with illumination light transmitted through the liquid crystal panel 52. As the photocatalytic substance used for the photocatalytic layer 54, for example, titanium oxide (TiO ₂ ) is generally used. When titanium oxide is used as the photocatalytic substance, as the light source 53 described above, a light source that emits illumination light including at least an ultraviolet wavelength band (a wavelength band of 380 nm or less) is used. Hereinafter, the photocatalytic layer 54 formed by using titanium oxide as the photocatalytic substance will be described.

When the light source 53 emits illumination light, the illumination light passes through the liquid crystal panel 52 and reaches the photocatalyst layer 54. Of the light reaching the photocatalyst layer 54, for example, light other than the wavelength band of ultraviolet rays (wavelength band exceeding 380 nm) passes through the photocatalyst layer 54 as it is. On the other hand, when light in the ultraviolet wavelength band (wavelength band of 380 nm or less) reaches the photocatalyst layer 54, the activity of electrons (e ⁻ ) called electrons contained in the photocatalyst material becomes active and enters an excited state. In response to this, a hole (h ⁺ ) is generated. The electrons change oxygen to superoxide ions (O ₂ ⁻ ), and holes change water to hydroxyl radicals (.OH). These superoxide ions (O ₂ ⁻ ) and hydroxyl radicals (.OH) are active oxygen, and when these active carbons come into contact with organic substances or organic gases present inside the camera body 12, organic substances or organic gases are removed. The “carbon-oxygen bond” and “carbon-hydrogen bond” that are formed are cut, and finally changed to carbon dioxide and water. Thus, for example, when the electronic viewfinder 34 is used at the time of photographing, active oxygen is generated in the above-described photocatalyst layer 54, and dirt attached to the surface of the photocatalyst layer 54 is removed.

  In addition, since the surface of the photocatalyst layer 54 becomes super hydrophilic during the above-described photoactivation process, for example, when moisture adheres to the surface of the photocatalyst layer 54, the water becomes the surface of the photocatalyst layer 54. It spreads under the dirt adhering to the surface of the photocatalyst layer 54. Thereby, the dirt adhering to the surface of the photocatalyst layer 54 is removed together with moisture adhering to the surface of the photocatalyst layer 54. In addition, since moisture adhering to the surface of the photocatalyst layer 54 spreads on the surface of the photocatalyst layer 54 and forms a water film, it is possible to prevent the LCD 51 surface from being fogged or condensed.

  The illumination light for photoactivating the photocatalyst layer 54 is originally illumination light from the light source 53 used when displaying an image on the LCD 51. Therefore, a new light source for photoactivating the photocatalyst layer 54 is newly provided. There is an advantage that it is not necessary to provide it. In other words, by using the LCD 51 having such a configuration as the image display device 41 of the electronic viewfinder 34, dirt that adheres to the surface of the image display device 41 when the electronic viewfinder 34 is used (when a through image is displayed). Therefore, it is not necessary to newly provide the electronic camera 10 with a light source that photoactivates the photocatalyst layer 54. In addition, although the display of the through image is taken up as an example as the image display in the image display device 41, the present invention is not limited to this. For example, when the power is turned on / off, the image display device 41 includes a photocatalyst layer made of titanium oxide. A blue image for photoactivation may be displayed.

  In the embodiment described above, the LCD 51 in which the photocatalyst layer 54 is formed on the front surface of the liquid crystal panel 52 is used as the image display device 41. In addition to this, the light directivity of the illumination light emitted from the light source is increased. It may be an LCD having a structure. Examples of the structure for enhancing the light directivity of the illumination light include a microlens array structure in which microlenses are arranged two-dimensionally, and a resonance amplification structure (optical cavity structure) by multiple reflection using a multilayer film. .

  FIG. 3 shows a configuration of the LCD 61 having a micro lens array structure. As shown in FIG. 3, the micro lens array structure 64 is provided between the liquid crystal panel 62 of the LCD 61 and the light source 63. As is well known, the microlens array structure 64 is a structure in which microlenses are arranged two-dimensionally. Examples of the microlens include a polygonal pyramid lens such as a cone, a triangular pyramid, and a quadrangular pyramid, and an irregular lens such as a dome-shaped lens. By providing such a microlens array structure 64 between the liquid crystal panel 62 and the light source 63, the illumination light emitted from the light source 63 can be condensed and applied to the liquid crystal panel 62. Further, the illumination light applied to the liquid crystal panel 62 is applied to the photocatalyst layer 65 after passing through the liquid crystal panel 62. Thus, by providing the microlens array structure 64, the illumination light emitted from the light source 63 can be efficiently illuminated on the liquid crystal panel 62 and the photocatalyst layer 65. The electronic viewfinder 34 only needs to have a viewing angle of 10 to 20 °. Therefore, even if the LCD 61 having such a configuration is used as the image display device 41 in the electronic viewfinder 34, the electronic viewfinder 34 is used. There is no loss of function.

  On the other hand, FIG. 4 schematically shows an LCD having a resonance amplification structure (hereinafter referred to as an optical cavity structure) by multiple reflection using a multilayer film. As shown in FIG. 4, also in the LCD 71, an optical cavity structure 74 is provided between the liquid crystal panel 72 and the light source 73. The optical cavity structure 74 has a structure in which transmission films and reflection films are alternately stacked. The interval between the reflection films, in other words, the thickness of the transmission film is an optical path length of a wavelength that photoactivates the photocatalyst layer 75. In this way, by setting the thickness of the transmission film (interval between the reflection films), among the illumination light transmitted through the optical cavity structure, for example, an ultraviolet wavelength band (wavelength of 380 nm or less) that photoactivates the photocatalytic layer 75 (Band) light is amplified. According to this, since the photocatalyst layer 75 can be efficiently irradiated with light in the ultraviolet wavelength band, the photoactivity of the photocatalyst layer 75 can be further increased. Also in this case, considering that the viewing angle of the electronic viewfinder 34 should be 10 to 20 ° as in the LCD 61 having the microlens array structure 64, the LCD 71 having such a configuration is used in the electronic viewfinder 34. Even if it is used as the image display device 41, the function of the electronic viewfinder 34 is not impaired.

  In the embodiment described above, only when the light source emits illumination light, in other words, only when the electronic viewfinder 34 is used, the photocatalytic layer formed on the surface of the image display device 41 is photoactivated, Although the stain on the surface of the image display device 41 is removed, the present invention is not limited to this, and the stain on the surface of the image display device 41 is removed even when the electronic viewfinder 34 is not used. It is also possible. Hereinafter, the case where an LCD including a thin film layer made of a phosphorescent material is used as the image display device 41 will be described.

In this case, as shown in FIG. 5, a thin film layer 84 of a phosphorescent material (hereinafter, phosphorescent layer 84) is provided between the liquid crystal panel 82 of the LCD 81 and the light source 83. The luminous layer 84 transmits the illumination light when illuminated with the illumination light from the light source 83 and accumulates the illuminated illumination light. In addition, the phosphorescent layer 84 emits light in a specific wavelength band when the light source 83 does not emit illumination light. The specific wavelength band includes an ultraviolet wavelength band (a wavelength band of 380 nm or less). Examples of the material used for the phosphorescent layer 84 include Zn ₂ SiO ₄ / PB / Mn, BaSi ₂ O ₅ , Zn ₂ SiO ₄ / Mn, (Zn, Be) ₂ SiO ₄ / Mn, and Ca ₃ (PO ₄ ). Oxygen-based phosphorescent materials such as ₂ ; sulfide-based phosphorescent materials such as CaS / Zn, SrS / Sm / Ce, and ZnO / Zn; or aluminum-based phosphorescent materials represented by SrAl ₂ O _4. It is done.

  By providing such a phosphorescent layer 84, when no illumination light is emitted from the light source 82, light in a wavelength band (ultraviolet wavelength band) that is photoactivated by the photocatalyst layer 85 for a certain period of time from the phosphorescent layer 84 is emitted. Irradiation is possible. Accordingly, even when the light source 82 does not emit illumination light, in other words, when the electronic viewfinder 34 is not used, the photocatalytic layer 85 can be photoactivated and the front surface of the image display device 41 can be activated. Can remove dirt.

  Instead of providing the phosphorescent layer 84, a layer (mixed layer) in which a photocatalytic substance and a phosphorescent substance are mixed can be formed on the front surface of the liquid crystal panel 82.

  The phosphorescent layer 84 can be combined with the above-described structure for enhancing the directivity of illumination light (the microlens array structure 64 or the optical cavity structure 74). In these cases, the phosphorescent layer may be provided between the light source and the minute lens array structure or the optical cavity structure, or between the minute lens array structure or the optical cavity structure and the liquid crystal panel.

In the above-described embodiment, the photocatalyst layer is formed on the front surface of the liquid crystal panel. However, the present invention is not limited to this. For example, a mixed layer of a photocatalyst material and an adsorbing material such as silica gel is formed on the front surface of the liquid crystal panel. It is also possible to do. In this case, moisture (H ₂ O) generated by the photoactivity of the photocatalytic substance can be adsorbed by an adsorbing substance such as silica gel, so that the dirt on the surface of the LCD can be removed simultaneously with the photoactivity of the photocatalytic layer. The moisture generated by the photoactivity of the photocatalyst layer can be adsorbed, and as a result, dew condensation occurring on the surface of the LCD can be prevented. The mixed layer is not limited to a mixed layer of a photocatalytic substance and an adsorbing substance, but may be a mixed layer in which a photocatalytic substance, an adsorbing substance, and a luminous substance are mixed.

In this embodiment, an example in which titanium oxide is used as a photocatalytic material is taken up, but the photocatalytic material is not limited to titanium oxide. As a photocatalytic substance, besides titanium oxide, zinc oxide (ZnO ₂ ), magnesium oxide (MgO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), bismuth oxide (Bi) ₂ O ₃ ) or iron oxide (Fe ₂ O ₃ ). Note that when a photocatalytic substance other than titanium oxide is used as the photocatalytic substance, a light source that emits illumination light including light in a wavelength band in which the photocatalytic substance to be used generates photoactivity may be used.

  In this embodiment, an electronic camera provided with an electronic viewfinder is taken as an example, but the present invention is not limited to this. For example, an electronic camera provided with an optical viewfinder may be used.

  FIG. 6 is a diagram illustrating an outline of the configuration of the electronic camera 100 including the optical viewfinder. In this case, the electronic camera 100 includes a lens unit 101 and a camera body 102 to / from which the lens unit 101 is attached / detached. The lens unit 101 includes an imaging optical system 111, a zoom encoder 112, a lens driving unit 113, a diaphragm 114, a diaphragm driving unit 115, a lens microcomputer 116, and the like. Since the configuration of the lens unit 101 is the same as the configuration of the lens unit 11, the description of the configuration of each part of the lens unit 101 is omitted.

  On the other hand, the camera body 102 includes a quick return mirror 121, a mechanical shutter 122, an image sensor 123, a sub mirror 124, a focus detection unit 125, a finder optical system, an image display device 126, a controller 127, and the like. Also in FIG. 6, the electrical configuration incorporated in the camera body 102 and the configuration of operation members such as a release button are omitted.

  The quick return mirror 121, the mechanical shutter 122, and the image sensor 123 are arranged along the optical axis L3 of the image pickup optical system 111. A sub mirror 124 is disposed behind the quick return mirror 121. A finder optical system is disposed on the upper part of the camera body 102. Further, a focus detection unit 125 is disposed in the lower region of the camera body 102.

  The quick return mirror 121 is pivotally supported about a rotation shaft 121a and can be switched between an observation state indicated by a solid line and a retreat state retracted from the optical axis L3. The quick return mirror 121 in the observation state is inclined and disposed in front of the mechanical shutter 122 and the image sensor 123. The quick return mirror 121 in this observation state reflects the light beam that has passed through the imaging optical system 111 in the direction of the optical axis L4 and guides it to the finder optical system. The central portion of the quick return mirror 121 is a half mirror, and a part of the light beam transmitted through the quick return mirror 121 is reflected by the sub mirror 124 in the direction of the optical axis L5 and guided to the focus detection unit 125. Note that the focus detection unit 125 performs so-called phase difference detection type focus detection in which an image shift amount of a subject image divided by a separator lens (not shown) is detected for each AF area.

  On the other hand, the retracted quick return mirror 121 is flipped upward together with the sub mirror 124 and rotated to a position off the photographing optical path. When the quick return mirror is in the retracted state, the light beam that has passed through the imaging optical system 111 is guided to the mechanical shutter 122 and the image sensor 123.

  The finder optical system includes a finder screen 131, a condenser lens 132, a pentaprism 133, and an eyepiece lens 134. Note that the finder screen 131 is located above the quick return mirror 121. A light beam reflected by the quick return mirror 121 in the observation state is imaged on the finder screen 131. The light beam formed on the finder screen 131 passes through the condenser lens 132 and the pentaprism 133 and is guided to the exit surface having an angle of 90 ° with respect to the incident surface of the pentaprism 133. Then, the light beam from the exit surface of the pentaprism 133 passes through the eyepiece lens 134 and then reaches the eyes of the user through the eyepiece window 135. Thereby, the through image is observed through the optical viewfinder.

  In the electronic camera 100 equipped with such an optical viewfinder, for example, the viewfinder screen 131 is composed of a transmissive image display device such as an EL element (including an organic EL element and an inorganic EL element). Photocatalyst layers are formed on the light incident surface and the light exit surface of the finder screen 131, respectively. In the case of the electronic camera 100 provided with such an optical viewfinder, the subject light taken in via the lens unit 101 reaches the optical viewfinder, so that a photocatalyst is applied to each of the light entrance surface and the light exit surface of the viewfinder screen 131. If the layer is formed, the photocatalytic layer is photoactivated by light having a wavelength band of 380 nm or less, such as ultraviolet rays contained in incident subject light. Thereby, the dirt adhering to the light incident surface and the light emitting surface of the finder screen 131 can be removed.

  In addition, when an EL element is used as the finder screen 131, it is also possible to provide a phosphorescent layer between the transparent electrode layer and the photocatalyst layer in addition to forming a photocatalyst layer on the surface thereof. It is also possible to form a mixed layer of a photocatalytic substance and an adsorbing substance, a mixed layer of a photocatalytic substance and a luminous substance, or a mixed layer of a photocatalytic substance, an adsorbing substance and a luminous substance on the surface of the EL element.

  In the present embodiment, the image display device 41 used for the electronic viewfinder 34 and the image display device used as the viewfinder screen 131 of the electronic camera 100 including the optical viewfinder have been described. The present invention can also be implemented for the image display devices 33 and 126 that display images for recording.

  Although an electronic camera is taken as an example of the present invention, it is not necessary to be limited to this. For example, in addition to a mobile phone having a camera function, the present invention can be applied to any electronic device having a configuration in which an image display device is incorporated inside the device, such as a head mounted display.

DESCRIPTION OF SYMBOLS 10 ... Electronic camera, 11 ... Lens unit, 12 ... Camera body, 33, 41 ... Image display device, 34 ... Electronic viewfinder, 51, 61, 71, 81 ... LCD, 52, 62, 72, 82 ... Liquid crystal panel, 53, 63, 73, 83 ... light source, 54, 65, 75, 85 ... photocatalytic layer, 64 ... micro lens array structure, 74 ... optical cavity structure, 84 ... phosphorescent layer, 131 ... finder screen

Claims (10)

A display for displaying an image;
A photocatalytic layer formed on the front surface of the display unit;
A light emitting unit that emits illumination light capable of illuminating the photocatalyst layer via the display unit,
The light emitting unit has a function of illuminating the photocatalyst layer by illuminating the photocatalyst layer, and a function of illuminating the display unit during image display on the display unit. The image display device according to claim 1,
An image display device comprising a structure for enhancing directivity of illumination light from the light emitting unit between the light emitting unit and the display unit. The image display device according to claim 2,
The image display apparatus according to claim 1, wherein the structure for increasing the directivity of the illumination light from the light emitting unit is a microlens array structure in which microlenses are two-dimensionally arranged. The image display device according to claim 2,
The image display apparatus according to claim 1, wherein the structure for enhancing the directivity of the illumination light from the light emitting portion is a multilayer film structure and a structure for resonantly amplifying light in a specific wavelength region. The image display device according to any one of claims 1 to 4,
The illumination light from the light emitting unit can be accumulated between the display unit and the light emitting unit, or between the display unit and the photocatalytic layer, and light in a wavelength region that becomes visible light is transmitted. An image display device comprising a thin film layer made of a phosphorescent substance. The image display device according to any one of claims 1 to 5,
The display unit includes a liquid crystal panel,
The image display device, wherein the light emitting unit includes a backlight that illuminates the liquid crystal panel from a back side. The image display device according to any one of claims 1 to 6,
The light emitting unit is composed of either an inorganic LED element or an organic LED element. The image display device according to any one of claims 1 to 7,
The photocatalytic layer comprises a thin film layer using titanium oxide as a photocatalytic substance,
The light emitting unit emits illumination light having a wavelength range of 380 nm or less.   9. An image pickup apparatus, wherein the image display apparatus according to claim 1 is incorporated as a finder. The imaging device according to claim 9,
The image display device incorporated as the viewfinder is disposed so that a front surface of the image display device is substantially parallel to a plane including a vertical direction with respect to the image pickup device body. .

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