JP5056922B2 - Display device, finder unit and imaging device - Google Patents

Description

The present invention relates to a display device, a finder unit, and an imaging device.

  A liquid crystal panel is a transmissive display device that can display necessary information superimposed on an optical image. For example, a liquid crystal panel using a polymer dispersed liquid crystal is used in a camera finder device. ing. This liquid crystal panel is a panel composed of a plurality of display segments having a liquid crystal layer in which a polymer-dispersed liquid crystal is sealed between two transparent substrates with transparent electrodes. This polymer-dispersed liquid crystal displays two types of modes, a transmission state in which light is transmitted and a diffusion state in which light is diffused, by controlling the electric field applied to the liquid crystal layer.

  When this liquid crystal panel is driven, the display segment to which an electric field is applied transmits light, and the display segment to which no electric field is applied diffuses (scatters) light. Thereby, when an optical image such as an outside scene is bright, the display segment looks dark. On the other hand, when the image is dark, the display segment can be made bright by illuminating the liquid crystal layer.

  On the other hand, Patent Document 1 discloses a structure of a finder device in which a guest-host type liquid crystal display panel is disposed between a pentaprism and a focusing screen. In this publication, in a finder device of a camera provided with a display body that performs display superimposed on a finder image in an optical path of a finder optical system, a first support body that holds the display body, and a combination with the first support body And a second support that holds the pentaprism, and a structure in which the first support and the second support hold the display in a space between each other in a combined state is disclosed.

JP-A-4-345150

  However, when an apparatus for illuminating a polymer dispersed liquid crystal display panel is arranged using the structure of the above publication, the illuminating apparatus jumps out of the first support. Since the first support is usually held by the front body of the camera, the illumination device interferes with the front body of the camera, making it difficult to incorporate.

  In order to solve this problem, it is conceivable to incorporate the lighting device after incorporating the first support body into the front body of the camera by devising the assembling order, but since the lighting device is not integrated with the finder unit, It is not preferable from the viewpoint of assembly.

The display device according to claim 1 includes a display panel in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is sealed, and light from a light source is displayed on the display surface of the display panel. A light guide portion that guides in a direction orthogonal to the light, a reflection portion that reflects light guided by the light guide portion, and light that is reflected by the reflection portion is emitted toward a surface orthogonal to the display surface of the display panel. And a light guide member having a light emitting portion that is configured such that light from the light source is reflected by a parabolic surface.
The display device according to claim 2, further comprising a conductive member connected to an electrode provided on the display panel in the display device according to claim 1, wherein the conductive member emits light from the emitting portion. It is characterized by limiting the range to be performed.
The display device according to claim 3 is the display device according to claim 1 or 2, wherein the display panel has a light shielding portion on a surface of the surface orthogonal to the display surface that does not face the emission portion. It is characterized by having.
According to a fourth aspect of the present invention, there is provided a display device in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is sealed, and light from a light source is displayed on the display surface of the display panel. A light guide portion that guides in a direction orthogonal to the light, a reflection portion that reflects light guided by the light guide portion, and light that is reflected by the reflection portion is emitted toward a surface orthogonal to the display surface of the display panel. A light guide member having a light emitting portion and a conductive member connected to an electrode provided on the display panel, wherein the conductive member limits a range in which light is emitted from the light emitting portion. And
The display device according to claim 5 is a display panel in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is sealed, and light from a light source is displayed on the display surface of the display panel. A light guide portion that guides in a direction orthogonal to the light, a reflection portion that reflects light guided by the light guide portion, and light that is reflected by the reflection portion is emitted toward a surface orthogonal to the display surface of the display panel. And a light guide member having a light-emitting portion, and the display panel includes a light-shielding portion on a surface that is not opposed to the light-emitting portion among surfaces orthogonal to the display surface.
A finder unit according to a sixth aspect includes the display device according to any one of the first to fifth aspects and a pentaprism.
An imaging device according to a seventh aspect includes the display device according to any one of the first to fifth aspects.

It is a figure which illustrates notionally the structure of the single-lens reflex camera incorporating the liquid crystal display illumination device by embodiment of this invention. It is a perspective view which shows the single-lens reflex camera by this embodiment. It is the perspective view which cut | disconnected the substantially center of the pentaprism of the single-lens reflex camera by this embodiment in the surface orthogonal to an optical axis. FIG. 2 is a perspective view showing a light guide device 40 that guides light from a light source 30 of FIG. 1 to an end face 10a of a display panel 10 and a holding structure thereof. FIG. 3 is a cross-sectional view showing the pentaprism 5 by cutting substantially the center thereof on a plane orthogonal to the optical axis. FIG. 6 is an enlarged view around the light guide 401 in FIG. 5. FIG. 6 is an enlarged view around the light guide 402 in FIG. 5. It is a figure which shows the selector 50 of the liquid crystal display illuminating device by this embodiment. 9 shows a state in which the center segment 101 is selected by the focus area selector 501 shown in FIG. It is a flowchart which shows operation | movement (main routine) of CPU8 of the liquid crystal display illuminating device by this embodiment. It is a flowchart which shows operation | movement (subroutine of selection area determination) of CPU8 of the liquid crystal display illuminating device by this embodiment.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a diagram conceptually illustrating the structure of a single-lens reflex camera incorporating a liquid crystal display illumination device according to an embodiment of the present invention. As shown in FIG. 1, the camera 1 includes a photographic lens 2 that forms an image of a subject on a film, a light-up reflection mirror 3 that switches an optical path from the photographic lens 2, and a surface conjugated to the film. A display panel 10 of polymer dispersed liquid crystal disposed in the vicinity of the screen 4, a pentaprism 5 for bending the light transmitted through the screen 4 and the display panel 10 for observation, And an eyepiece 6 for observing an image projected on the screen 4. Here, the display panel 10 is held by the holder 20 and fixed to the camera.

  In addition to the display panel 10, the camera 1 includes a light source 30 including LEDs, a light guide device 40 that guides light from the light source 30 to the end face 10 a of the display panel 10, and the display panel 10. A driving circuit 7 for driving, a CPU 8, a selector 50 for selecting a segment of the display panel 10, and the like are provided.

  As shown in FIG. 4 described later, the display panel 10 includes five segments 101 to 105, and one of the segments 101 to 105 is selected by the selector 50. The display panel 10 is also a segment in the background other than the segments 101 to 105 (background region, that is, a portion that occupies most of the area and transmits the image projected on the screen 4 as it is), and is always transparent. It is driven to become. On the display panel 10, since the left and right sides are not reversed by the pentaprism 5 with respect to the case of actually observing through the eyepiece lens 6, the positions of the left segment 104 and the right segment 105 are reversed.

  For example, as shown in FIG. 8, the selector 50 includes four switches 51 to 54 and can use a focus area selector 501 that detects that the switch is pushed in four directions, up, down, left, and right. FIG. 9 shows a state where the center segment 101 is selected by the focus area selector 501 shown in FIG.

  The CPU 8 is a central processing unit that comprehensively controls the operation of the camera 1 based on signals from an AE device, an AF device, etc. (not shown). In this embodiment, the CPU 8 is further based on a signal from the selector 50. Thus, the display state of the display panel 10 is controlled via the drive circuit 7. The drive circuit 7 is a circuit that operates based on an instruction from the CPU 8.

  Since the camera 1 shown in FIG. 1 has the display panel 10 arranged close to the screen 4 as in the configuration described above, the image light imaged on the screen 4 by the photographing lens 2 is reflected on the back of the display panel 10. Pass through the ground (background area). When any part of the display panel 10 other than the background (that is, the display segments 101 to 105) is in a diffused state, the light incident on this part is diffused and scattered in all directions. Therefore, only a small amount of light travels in the direction of the eyes. Therefore, the portion displayed with the light amount of this portion lowered becomes darker than the background. That is, the display panel 10 optically superimposes the background and the display pattern.

  When sufficient light does not reach the screen 4, the light source 30 is turned on, and an appropriate amount of illumination light is incident from the end face 10 a of the display panel 10, thereby superimposing a bright display pattern in a dark background. Impose and display. In this case, since the light is diffused in the displayed segment (any one of the segments 101 to 105), a part of the illumination light is also diffused in the direction of the observer's eyes. Segments appear bright. However, when the luminance of the subject is sufficiently bright, the illumination light is too dark compared to the luminance of the subject even if the light source 30 is turned on and the illumination light is incident from the end face 10a of the display panel 10, so that the brightness is high. Instead of a display pattern, a dark display pattern is superimposed on a light background.

  FIG. 2 is a perspective view showing the single-lens reflex camera 1 according to the present embodiment, and FIG. A cartridge chamber 1001 of the body 1000 is placed on the right side of the pentaprism 5 after loading a cartridge (not shown). On the left side, a mirror drive mechanism, a built-in electronic board for a built-in strobe, a capacitor, a DC-DC converter, and the like A part 4000 is arranged. The front body 2000 is a portion on which a bayonet mount 3000 that is coupled to a lens mount (not shown) disposed at the rear end of the lens barrel of the photographing lens 2 and a finder unit to be described later are mounted.

  Next, the detailed structure of the liquid crystal display illumination device integrated with the finder unit according to the present embodiment will be described. 4 is a perspective view showing a light guide device 40 for guiding the light from the light source 30 of FIG. 1 to the end face 10a of the display panel 10 and its holding structure, and FIG. 5 shows the pentaprism 5 on a surface orthogonal to the optical axis. FIG. 6 is an enlarged view around the light guide 401 in FIG. 5, and FIG. 7 is an enlarged view around the light guide 402 in FIG. 1 to 7, the same members are denoted by the same reference numerals.

  As shown in FIGS. 4 and 5, the holder 20 shown in FIG. 1 includes two members, a lower holder 201 and an upper holder 202, and holds the display panel 10 in between. A pressing member 203 (FIGS. 5, 6, and 7) is inserted between the upper holder 202 and the display panel 10 so that the display panel 10 is securely sandwiched and fixed between the upper and lower holders 201 and 202. ing. The pressing member 203 is made of an elastic material such as rubber, Neoprene (registered trademark) sponge or flocked paper, and fixes the vertical position of the display panel 10 and also fixes the position in the display plane direction so as not to move. To do. The lower holder 201 and the upper holder 202 are substantially box-shaped so that the upper holder 202 can enter the lower holder 201.

  The display panel 10 shown in FIG. 1 includes an upper glass 106 and a lower glass 107, and a liquid crystal material is sealed between the upper and lower glasses 106 and 107 to perform display. Further, as shown in FIG. 4, a plurality of electrodes 107 a are arranged on the lower glass 107, and the upper glass 106 is shortened in that portion. These electrodes 107a are connected to the segments 101 to 105 of the display panel 10 and the background, and supply electric power for controlling the display state of these segments.

  The light guide device 40 shown in FIG. 1 includes two right and left light guides 401 and 402, and is disposed in the vicinity of the end face of the display panel 10 in a direction parallel to the optical axis of the photographing lens 2. Accordingly, light emitted from the emission surfaces 401 d and 402 d of the light guides 401 and 402 is incident from an end surface in a direction parallel to the optical axis of the photographing lens 2 of the display panel 10. The light guide 401 is made of transparent polycarbonate or acrylic, and end surfaces 401a and 401b reflecting light corresponding to both end surfaces of the light guide portion have a parabolic surface shape. The reflective surface 401c is preferably vapor-deposited with a metal having high reflectivity such as aluminum or silver. However, when the refractive index of the light guide 401 is relatively large, such as polycarbonate, a light beam close to parallel light is reflected. In view of cost effectiveness, vapor deposition is not necessarily required.

  Since the reflecting surface 401c is provided, the light guide 401 is within the width dimension of the lower holder 201 in the lateral direction. Without this reflection surface 401c, the light guide 401 protrudes from the reflection surface 401c to the left side in FIG. 5 by the dimension above the reflection surface 401c in FIG. Further, the light guide 401 has an incident light exit surface 401d as shown in FIG. The thickness of the light guide 401 at the exit surface 401d is substantially the same as the thickness of the display panel 10.

  Like the light guide 401, the light guide 402 is made of transparent polycarbonate or acrylic, and end surfaces 402a and 402b reflecting light corresponding to both end surfaces of the light guide section have a parabolic surface shape. The reflective surface 402c is preferably vapor-deposited with a metal having high reflectivity such as aluminum or silver. However, a material having a relatively large refractive index value such as polycarbonate reflects a light beam close to parallel light. Since it is easy, vapor deposition is not necessarily required in consideration of cost effectiveness.

  In addition, since the reflection surface 402c is provided, the light guide 402 is within the lateral dimension of the lower holder 201. Without this reflecting surface 402c, the light guide 402 protrudes from the reflecting surface 402c to the right side in FIG. 5 by the dimension above the reflecting surface 402c in FIG. Reference numeral 402d denotes an exit surface for incident light.

  As shown in FIGS. 5 and 7, the light guide 402 has an exit surface 402d substantially the same as the vertical length of the reflection surface 402c in FIGS. However, as will be described later, in order to enable connection between the electrode 107a of the lower glass 107 and the flexible printed board 120 using the zebra rubber 110, the upper glass 106 where the zebra rubber 110 is disposed is cut out. Due to such a structure, the size of the substantial exit portion of the exit surface 402 d of the light guide 402 is substantially the same as the thickness of the lower glass 107 of the display panel 10.

  The light source 30 shown in FIG. 1 includes two LEDs 301 and a driving circuit (not shown). The two LEDs 301 have respective notches 401e and 402e (FIG. 5) such that the light emitting portions thereof are the focal positions of the parabolic surface shapes 401a, b, 402a, and b of the light guides 401 and 402, respectively. It is mounted on the flexible printed circuit board 120 so as to be arranged so as to enter (FIGS. 6 and 7).

  In this way, the light emitting portions of the two LEDs 301 are arranged so as to enter the respective notches 401e and 402e so that the light guide portions of the parabolic surface shapes 401a, b, 402a, and b of the light guides 401 and 402 become the focal positions. Then, based on the principle of a parabolic mirror, the LED light is output as parallel light perpendicular to the end surfaces 401d and 402d of the light guides 401 and 402, respectively. Therefore, uniform bright light based on the principle of a parabolic mirror is output from the end surfaces 401 d and 402 d of the light guides 401 and 402. Therefore, only one LED is arranged for each of the light guides 401 and 402, and the substantial width of the end surfaces 401d and 402d of the light guides 401 and 402, that is, the thickness of the display panel 10 is determined in the light guide 401. The light guide 402 can perform bright and uniform illumination within the thickness range of the lower glass 107. For this reason, it is possible to perform bright and uniform illumination with respect to any of the focus areas 101 to 105.

  The substantial emission dimension of the emission surface 402d of the light guide 402 is about ½ of the emission dimension of the emission surface 401d of the light guide 401. For this reason, the amount of the LED light incident on the display panel 10 is determined by the size of the portion where the LED light enters the light guide, but the larger size is larger than the smaller size. However, when the end surfaces 401a, b, 402a, b of the light guides 401, 402 reflecting the light have a parabolic shape as in the present invention, the light guides 401, 402 are emitted according to the principle of a parabolic mirror. Since the light emitted from the substantial emission parts of the surfaces 401d and 402d reaches far, a slight difference in the amount of light hardly affects the brightness of the segments 101 to 105 illuminated. For the same reason, even if the brightness difference between the two LEDs 301 is several times, the brightness of the illuminated segments 101 to 105 is hardly affected.

  On the other hand, when the LED light is incident on the liquid crystal layer, even if it is a transparent portion in the liquid crystal layer, it has a slight degree of scattering, so when the LED light passes through the transparent portion of the liquid crystal layer, the background is dark. In this case, the transparent portion is lit by the LED light. Therefore, as shown in FIGS. 5 and 6, a polarizing plate 91 is inserted between the end surface 10 a of the display panel 10 and the light guide 401, and LED light is transmitted through the transparent portion of the liquid crystal layer. It has a structure that makes it difficult to go out to the display surface. Thereby, the phenomenon that the transparent part of the display panel 10 shines is significantly reduced.

  Although the light quantity of the two LEDs 301 decreases due to the insertion of the polarizing plate 91, as described above, the reflecting surfaces 401a and 401b of the light guide 401 become parabolic surfaces, and the light quantity of the LED 301 is effectively used. Therefore, there is no influence of the light amount reduction due to the insertion of the polarizing plate 91.

  Moreover, since the difference in the thickness of the substantial exit portion of the exit surfaces 401d and 402d of the light guides 401 and 402 has a slight influence on the brightness of the segments 101 to 105, the light guide 402 is displayed. A polarizing plate 92 is not inserted between the panel 10. For this reason, the LED light output from the light guide 402 enters the display panel 10 without being attenuated. On the other hand, the large amount of light output from the light guide 401 is closer to the attenuated amount of light, and the illuminated brightness of the segments 101 to 105 is substantially uniform.

  Further, black ink painting (light-shielding portion) is applied to the other two end faces 10b (FIG. 4) of the display panel 10. As a result, even if the light of the LED 301 reaches the end surface 10b of the display panel 10 due to scattering in the liquid crystal layer, it is absorbed without being reflected here, so that the transparent portion of the display panel 10 also shines. It is greatly reduced.

  The lower glass 107 of the display panel 10 is provided with an electrode 107a for switching between the transparent state and the diffusion state of the segments 101 to 105 and for maintaining the transparent state of the background other than the segments 101 to 105. In order to connect to the CPU 8 in FIG. 1, the electrode 107 a and the flexible printed board 120 are electrically connected via the zebra rubber 110. Further, the two LEDs 301 also constitute a light source 30 from a drive circuit (not shown), and are electrically connected to the CPU 8 in FIG. The finder unit configured as described above is fitted into the front body 2000 and fixed with screws (not shown).

  Next, the operation of the liquid crystal display illumination device according to the present embodiment will be briefly described. 10 and 11 are flowcharts showing the operation of the CPU 8 of the liquid crystal display illumination device according to the present embodiment. When the battery is loaded, the operation starts and S1 is executed. In S1, 0 is set in the parameter A. The parameter A indicates the selected segment, where 0 is the center, 1 is the right, 2 is the left, 3 is the top, and 4 is the bottom. As described above, when the battery is first loaded in the camera, the drive circuit 7 sets 0 in the parameter A so that the central segment 101 is in the diffusion state.

  In S2, it is determined whether the focus area selector 501 has been pressed in the up, down, left, or right direction. Details will be described with reference to FIG. In FIG. 11, 1 is set in the flag F in S201. This flag F is set to 0 when the focus area selector 501 is not pressed in any of the upper, lower, left and right directions, and indicates whether or not the focus area selector 501 has been operated.

  In S202 to S208, when the switch 51 is pressed, it is determined which segment is to be in the diffusion state next depending on which segment was in the diffusion state before that. If any of the center, upper, and lower segments is currently in a diffuse state (A is 0, 3 or 4), 1 is entered in A so that the right segment is in a diffuse state. If the left segment is currently in a diffusion state (A = 2), 0 is entered in A so that the central segment is in a diffusion state. When the right segment is currently in a diffusion state (A = 1), the diffusion state of the right segment only needs to be maintained, and the value of parameter A is not changed.

  In S209 to S215, a change process to the left is performed in the same manner as described above. In S216 to S222, an upward change process is performed in the same manner as described above. In S223 to S229, a downward change process is performed in the same manner as described above.

  In S230, when none of the switches 51 to 54 is pressed and the focus area selector 501 is not operated, 0 is set in the flag F. When the above is completed, the process returns to S3 in FIG.

  In FIG. 10, the flag F is determined in S3. If F = 0, the focus area selector 501 is not operated, and the process returns to S2. If F = 1, the focus area selector 501 has been operated, and the process proceeds to S4.

  In S4, an update signal is output to the drive circuit 7 so that the segment selected in S2 described above is displayed on the display panel 10 in a diffused state. In response to this, the drive circuit 7 outputs a signal for setting the segment in the current diffusion state on the display panel 10 to the transmission state and setting the selected segment to the diffusion state.

  In S5, the drive circuit (not shown) of the light source 30 causes the two LEDs 301 to emit light for a predetermined time (about 300 msec), brightly illuminate the diffused segment of the display panel 10, and returns to S2 described above.

  As described above, according to the present embodiment, the light guide device 40 that guides light from the illumination LED 301 to the display panel 10 includes the light guides 401 and 402. In the light guides 401 and 402, the reflection surfaces 401a and 402a have a parabolic surface shape, and the LED 301 is disposed substantially at the focal positions 401b and 402b. For this reason, it can illuminate brightly and uniformly regardless of the position of the segment in the diffusion state selected by the display panel 10.

  In addition, reflecting surfaces 401c and 402c are provided on the light guides 401 and 402, respectively, and the optical system is bent. For this reason, the light guides 401 and 402 can be disposed within the lateral width of the lower holder 201 and can be incorporated as a finder unit. If the reflecting surfaces 401c and 402c of the light guides 401 and 402 are not provided, the same optical path length as that required when the light guides 401 and 402 are extended is required. The dimension which reduced the thickness of the horizontal part will protrude to the left and right respectively. Since this is larger than the lateral dimension of the front body 2000, the lateral dimension of the camera is increased, and the camera is not only enlarged but also inserted into the front body 2000 from above as a finder unit. It will not even be possible, and the embedding will be worse.

  The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention. In the present embodiment, the shape of the light guide is a parabolic surface. However, the present invention is not limited to this, and if the light in the light guide is reflected by the parabolic surface, the above-described effects are exhibited. The

  In addition, as the liquid crystal for the display panel 10, polymer dispersed liquid crystal is used as an example. However, the liquid crystal is not limited to this, and any light scattering type liquid crystal may be used. Also good.

  DESCRIPTION OF SYMBOLS 1 Camera, 2 Shooting lens, 3 Reflection mirror, 4 Screen, 5 Penta prism, 6 Eyepiece lens, 7 Drive circuit, 8 CPU, 9 Photometric element, 10 Display panel, 20 Holder, 30 Light source, 40 Light guide device, 50 Selector , 51-54 switch, 91 polarizing plate, 101-105 segment, 106 upper glass, 107 lower glass, 107a electrode, 301 LED, 401, 402 light guide, 401a, 402a end face, 401b, 402b focal position, 401c, 402c end face , 401d, 402d reflective surface, 110 zebra rubber, 120 flexible printed board, 501 focus area selector

Claims (7)

A display panel in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is enclosed;
A light guide that guides light from a light source in a direction perpendicular to the display surface of the display panel; a reflector that reflects the light guided by the light guide; and the light reflected by the reflector A light guide member having an emission portion that emits toward a surface orthogonal to the display surface,
The light guide unit is configured such that light from the light source is reflected by a parabolic surface.
A display device. The display device according to claim 1,
A conductive member connected to an electrode provided on the display panel;
The conductive member limits a range in which light is emitted from the emitting portion.
A display device. The display device according to claim 1 or 2,
The display panel has a light-shielding portion on a surface that is not opposed to the emitting portion among surfaces orthogonal to the display surface.
A display device. A display panel in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is enclosed;
A light guide that guides light from a light source in a direction perpendicular to the display surface of the display panel; a reflector that reflects the light guided by the light guide; and the light reflected by the reflector A light guide member having an emission portion that emits toward a surface orthogonal to the display surface;
A conductive member connected to an electrode provided on the display panel,
The conductive member limits a range in which light is emitted from the emitting portion.
A display device. A display panel in which a liquid crystal layer for switching between a diffusion state in which light is diffused and a transmission state in which light is transmitted is enclosed;
A light guide that guides light from a light source in a direction perpendicular to the display surface of the display panel; a reflector that reflects the light guided by the light guide; and the light reflected by the reflector A light guide member having an emission portion that emits toward a surface orthogonal to the display surface,
The display panel has a light-shielding portion on a surface that is not opposed to the emitting portion among surfaces orthogonal to the display surface.
A display device. A display device according to any one of claims 1 to 5,
Having a penta prism
Finder unit characterized by A display device according to any one of claims 1 to 5 is provided.
An imaging apparatus characterized by the above.

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