JP2000162695A - Display device and finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a situation in which a light beam leaking out from a light source for illuminating a display device penetrates into an undesired spot and is reflected, so that the viewing quality of a display device is lowered. SOLUTION: A display unit 10 is disposed in the optical path of a finder for a camera, and an FPC 16 is connected to the unit 10. An LED 14 is disposed in the vicinity of the unit 10, and light shown by the arrow (t) from among the light emitted from the LED 14 is made incident only on a transparent base plate 13, positioned on an ocular side out of the transparent base plates 12 and 13 constituting the unit 10. The light shown by the arrow (s) is intercepted by the FPC 16 and will not advance to the inside of the finder or the inside of the base plate 12. Thus, a situation in which the light emitted from the LED 14 being reflected on the surface of an objective system lens 24 and flares and ghosts occurring in the finder is restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device using liquid crystal which can be switched between a diffusion state in which light is diffused and a transmission state in which light is transmitted, and a finder provided with this display device.

[0002]

2. Description of the Related Art A camera finder using a polymer-dispersed liquid crystal display device is known (for example, see Japanese Patent Application Laid-Open No.
No. 313973). Polymer-dispersed liquid crystal display devices
When no voltage is applied, the liquid crystal molecules are randomly arranged and become turbid, and when illuminated with white illumination light, they exhibit a cloudy appearance (diffusion state). On the other hand, when a voltage is applied, the liquid crystal molecules are arranged in the direction of the electric field, so that the incident light is transmitted and the liquid crystal molecules have a transparent appearance (transparent state). When this polymer-dispersed liquid crystal display device is used in a viewfinder of a camera, for example, when shooting in a dark place, by turning on a light source in the viewfinder, a cloudy portion where information is to be presented is illuminated and placed in a dark background. It looks bright and raised. Thus, there is an advantage that the displayed information can be easily recognized even in a dark place.

FIG. 7 is a sectional view of a real image type finder (hereinafter simply referred to as a finder) of a camera. The viewfinder includes objective lenses 121 to 124, roof prism 125
An objective optical system 120 made up of
An eyepiece optical system 130 including an eyepiece 132, a display unit 110 disposed between the objective optical system 120 and the objective optical system 130, and an LED 114 for illuminating the display unit from the side. Power for illumination is supplied to the LED 114 via a flexible printed circuit board (hereinafter, referred to as FPC). The finder image formed by the objective optical system 120 is formed in the vicinity of the display unit 110, and the photographer can see the display of the display unit 110 superimposed on the finder image via the eyepiece optical system 130.

The display unit 110 is composed of a polymer dispersed liquid crystal 111 and two transparent glass substrates 112 and 113 which seal the polymer dispersed liquid crystal 111 therebetween. A transparent electrode is formed on the polymer dispersed liquid crystal 111 side (inside) of the two transparent glass substrates 112 and 113, and this transparent electrode is connected to the FPC.

FIG. 8 is an enlarged sectional view of the vicinity of the display unit 110 of the above-described finder. In FIG.
Representative light among the light emitted from the LED 114 is indicated by light indicated by arrows p, q, and r. The light indicated by the arrow p emitted from the LED 114 is transmitted to the transparent glass substrate 113.
, Further incident on the transparent glass substrate 112, and are reflected by the surface of the transparent glass substrate 112 on the roof prism 125 side (hereinafter, referred to as the object side). This light travels through the transparent glass substrate 112 again, passes through the polymer dispersed liquid crystal 111 in a transmission state, and travels through the transparent glass substrate 113. The side of the transparent glass substrate 113 on the side of the pentaprism 131 (hereinafter, this is referred to as the eyepiece side)
The light is reflected on the surface on the eyepiece side, reaches the surface on the eyepiece side of the polymer dispersed liquid crystal 111 in a diffused state, and illuminates the polymer dispersed liquid crystal. The light indicated by the arrow p described above is desirable light for illumination.

[0006]

However, in the viewfinder shown in FIGS. 7 and 8, there is a problem that the internal light is reflected by a part of the light emitted from the LED 114, and the viewability of the viewfinder is reduced.

The above problem will be described with reference to FIG. Light indicated by an arrow q emitted from the LED 114 is incident on the transparent glass substrate 112, and a part of the light is transmitted through the transparent glass substrate 112, while the remaining light is the surface of the transparent glass substrate 112 on the object side. a, is incident on the back side of the polymer-dispersed liquid crystal 111,
When the polymer dispersion type liquid crystal 11 is in a scattering state,
Irradiate 1. For this reason, the light reflected (scattered) on the object side of the polymer dispersed liquid crystal 111 in the scattering state is reflected on the surface of the objective lens 124, the roof prism 125, and the like, and proceeds toward the eyepiece again.

The light emitted from the LED 114 is indicated by an arrow r
The light traveling along passes through the gap between the display unit 110 and the objective lens 124 into the viewfinder, is reflected by the surface of the objective lens 124, and travels toward the eyepiece.

[0009] The light traveling along these arrows q and r causes flare and ghost in the field of view of the finder.
This reduces the appearance of the viewfinder.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device, in which light leaking from a light source for illuminating a display device enters an undesired portion and is reflected, causing the display content itself of the display device to be seen. An object of the present invention is to suppress a decrease in the visual appearance.

[0011]

FIG. 1 shows an embodiment of the present invention.
The present invention will be described with reference to FIG. (1) According to the first aspect of the present invention, the first transparent substrate 13 and the first transparent substrate 13 located on the side of the observation surface are provided with the liquid crystal 11 which changes into a state of diffusing or transmitting light according to an applied voltage. A display unit 10 sealed between the second transparent substrates 12 located on the back side of the observation surface opposite to the display unit 13;
An illumination unit 14 for illuminating the display unit 10; and a shielding member 16 for shielding a light beam coming from the illumination unit 14 toward the display unit 10 to enter the second transparent substrate 12. Achieve the above objectives. (2) The invention according to claim 2 provides the finder optical system 2
A liquid crystal 11 that changes into a state of diffusing or transmitting light in accordance with an applied voltage is sealed between the first and second transparent substrates 13 and 12; Is on the eyepiece side of the finder optical systems 20 and 30, and the second transparent substrate 12 is
Display units 1 located on the object side of the finder optical systems 20 and 30, respectively, located on the object side of the finder optical systems 20 and 30
0; a circuit board 16 connected to the display unit 10;
Illumination means 14 for illuminating the display unit 10; light emitted from the illumination means 14 blocks light beams which are going to enter the optical path of the second transparent substrate 12 and / or the finder optical systems 20 and 30. Lighting means 14
And a circuit board 16 are provided. (3) The following description will be made with reference to FIG. 4 showing an embodiment. According to the third aspect of the present invention, the width dimensions of the circuit board 16 and the display unit 10 in the vicinity of the connection portion between the circuit board 16 and the display unit 10 are described. In this regard, the width dimension A of the circuit board 16 is larger than the width dimension B of the display unit 10. (4) The following description will be made with reference to FIG. 6 showing an embodiment. According to the invention described in claim 4, a reflection provided on the circuit board 16B for reflecting light emitted from the illumination means 14 is provided. Means for illuminating the display unit 10 with the light reflected by the reflection means 17; (5) Explaining in connection with FIG. 5 showing one embodiment, the invention according to claim 5 is a unit structure in which the lighting means 14 and the display unit 10 are integrally connected via a circuit board 16A. It has.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a cross section along an optical axis of a camera finder to which the present invention is applied. The finder includes an objective optical system 20 including objective lenses 21 to 24 and a roof prism 25, an eyepiece optical system 30 including a pentaprism 31 and an eyepiece 32, and a display unit 10 disposed between the two optical systems 20 to 30. And Then, a finder image is formed near the display unit 10 by the objective optical system 20. These objective optical system 20 and display unit 1
0 and the eyepiece optical system 30 are housed in the housing 18. Except for the display unit 10, the configuration is the same as that of the finder according to the related art described above.

The display unit 10 comprises a polymer dispersed liquid crystal 1
1 and two transparent substrates 12 and 13 for sealing with a polymer-dispersed liquid crystal 11 interposed therebetween. As in the case of the polymer-dispersed liquid crystal 111 (FIG. 7) installed in the finder according to the conventional technique, a transparent electrode is formed on each of the two transparent substrates 12 and 13 on the polymer-dispersed liquid crystal 11 side. The FPC 16 is connected to the transparent electrode formed on the transparent substrate 13. An LED 14 for illumination to which a current is supplied via an FPC 15 is fixed to an LED fixing portion 18 a formed in the housing 18, and emits illumination light from the side of the polymer dispersed liquid crystal 11.

FIG. 2 is a block diagram schematically showing an electric circuit of a camera provided with the finder according to the present embodiment. C
The PU 41 controls the display state of the display unit 10 and controls the entire camera, and includes a microprocessor and peripheral circuits. The CPU 41 includes a photometry unit 43 for measuring the brightness of the subject, an autofocus unit 44 for performing automatic focus adjustment, a driver 42 for driving the display unit 10, and a main switch 45 for turning on / off the power of the camera. , The above-mentioned illumination LED 14 and the like are connected. The display state of the display unit 10 is controlled by the CPU 4 via the driver 42.
1 is controlled. In addition, turning on / off of the LED 14 is also controlled by the CPU 41.

FIG. 3 is an enlarged view of the vicinity of the display unit 10 in the finder shown in FIG. LE
D14 is, for example, when the CPU 41 determines that the field luminance is low based on the photometric result input from the photometric unit 43, for example, when it is determined that the built-in flash of the camera needs to emit light, or the like. CPU
Current is supplied from 41 to emit light. The camera may be provided with an illuminating switch (not shown), and the CPU 41 may determine that the photographer has operated the switch and cause the LED 14 to emit light. Alternatively, the LED 14 may be caused to emit light in conjunction with the photographer half-pressing the release button (not shown) regardless of the field luminance or the like.

FIG. 4 is a view showing the appearance of the display unit 10 viewed from the object side. On the front side of the transparent substrate 13 (on the back side of the paper in FIG. 4), a chromium oxide film is deposited at a position indicated by hatching, thereby forming a light shielding mask. That is, the inside of the hatched portion of the display unit 10 in FIG. 4 is the effective display section. FIG. 4 shows a state where the CPU 41 controls the effective display section of the display unit 10 to be in a transmissive state except for the AF target mark 10a. Then, the portion of the AF target mark 10a is in a scattering state, and when the photographer looks into the viewfinder, the image of the subject and the AF target mark appear to overlap in the field of view.

In this state, when light is emitted from the LED 14, light as shown by an arrow t in FIG. 3 is scattered by the cloudy portion of the scattered AF target mark 10a, and the photographer looks into the finder. Incident on the eye. As a result, even if the viewfinder field is relatively dark,
The photographer can clearly recognize the AF target mark. Further, if there is a display segment other than the AF target mark, it can be illuminated with light as indicated by an arrow r in FIG. The light indicated by the arrow r will be further described.
Is transmitted through a portion of the polymer dispersed liquid crystal 11 in a transmission state (a portion shown in white in FIG. 3) and proceeds into the transparent substrate 12. This light is reflected on the surface of the transparent substrate 12 on the object side, travels through the transparent substrate 12 again, passes through a portion of the polymer-dispersed liquid crystal 11 in a transmission state, and enters the transparent substrate 13. Then, the light is reflected by the surface on the eyepiece side of the transparent substrate 13 and travels toward the portion where the polymer dispersed liquid crystal 11 is in the diffusion state, and illuminates the portion where the polymer dispersed liquid crystal is in the diffusion state. The refractive index of the polymer-dispersed liquid crystal 11 is substantially equal to the refractive indexes of the transparent substrates 12 and 13. Therefore, as described above, when the light traveling in the transparent substrate 12 or 13 is incident on the portion of the polymer dispersed liquid crystal 11 that is in the transmission state, the light travels straight without undergoing any refraction or reflection.

On the other hand, of the light emitted from the LED 14, the light ray indicated by the arrow s in FIG. 3 is shielded by the FPC 16, so that no harmful flare or ghost is formed in the viewfinder field. Further, as shown in FIG. 4, in the vicinity of the connection between the FPC 16 and the display unit 10, the FPC is larger than the width B of the display unit 10.
Since the width A of the LED 16 is increased, light emitted from the LED 14 at a relatively wide angle as shown by arrows w1 and w2 is also effectively blocked. on the other hand,
The light indicated by the arrow t enters the transparent substrate 13 disposed on the viewing side of the finder from the side thereof,
The process proceeds to the effective display section of the display unit 10 while repeating reflection on two surfaces orthogonal to the thickness direction.

The degree of light blocking by the FPC 16 need not be such that light emitted from the LED 14 does not enter the finder or the transparent substrate 12 at all. What is necessary is just to reduce the appearance of the viewfinder to the extent that it does not significantly impair the appearance.

Second Embodiment FIG. 5 shows a finder according to a second embodiment.
FIG. 2 is a cross-sectional view showing a portion where a display unit 10 is provided and details in the vicinity thereof. The configuration of the entire finder is the same as that of the finder according to the first embodiment shown in FIG. 1, and illustration and description thereof are omitted. Also, in FIG.
The same components as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 5, the LED 14 is connected to the display 10
That it is directly mounted on the FPC 16A connected to
The shape of the LED fixing portion 18Aa formed on the housing 18A is different from that of the first embodiment shown in FIG.

Of the light emitted from the LED 14, the light along the arrow s is shielded by the FPC 16A and does not enter the finder. 10a (see FIG. 4) is illuminated.

Further, since the LED 14 is directly mounted on the FPC 16A, the FPC for the LED 14 and the FPC for the display unit 10 can be shared, and the number of assembling steps and component costs can be reduced. Since the LED 14 is held together with the FPC 16A from the rear side of the FPC 16A by the LED fixing portion 18Aa of the housing 18A, the FPC 16A is fixed to the LED fixing portion 18Aa by the elastic restoring force of the FPC 16A itself even if it is not particularly adhered. Since the position of the LED 14 is also fixed, the number of assembly steps is reduced.

Third Embodiment FIG. 6 shows a finder according to a third embodiment.
FIG. 3 is a diagram illustrating details of a portion where a display unit 10 is provided and the vicinity thereof. FIG. 6A shows a cross-sectional view thereof.
FIG. 6B shows a connection state between the FPC 16B and the display unit 10 and a state in which the reflection member 17 is attached to the FPC 16B. FIG. 6B shows the display unit 10 and the FPC 16B, and a reflection member attached to the FPC 16B and an LED mounted on the FPC 16B in order to avoid complication of the drawing.
Only 17 is shown. Figure 1 shows the configuration of the entire finder.
Is the same as that of the finder according to the first embodiment, and its illustration and description are omitted. In FIG. 6, the same components as those of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 6A, the point that the light emitting portion of the LED 14 does not face the end of the display unit 10 (the portion where the illumination light is incident), the point that the reflecting member 17 is attached to the FPC 16B, The first and second embodiments are different from the first and second embodiments in that the LED fixing portion 18a (18Aa) provided on the housing 18 (18A) in the first and second embodiments is replaced with an FPC guide portion 18Bb. Different.

As shown in FIG. 6B, the LED 14
It is mounted on the PC 16B and, as shown in FIG. 6A, is fixed to the housing 18B so as to face a concave surface formed on the FPC guide portion 18Bb.

Of the light emitted from the LED 14, the light indicated by the arrow u is reflected by the reflection member 17 and
No. 3 is incident. The light indicated by the arrow v is reflected by the reflection member 17 and then blocked by the FPC 16B, so that the light does not enter the viewfinder.

In the finder according to the third embodiment,
Since the light emitted from the LED 14 is reflected by the reflection member 17 and condensed, and guided to the end of the transparent substrate 13, L
The light emitted from the ED 14 can be used efficiently. At this time, by changing the curved shape of the FPC guide portion 18Bb, the curvatures of the FPC 16B and the reflecting member 17 can be changed, so that the light condensing performance of the reflecting member 17 can be optimized, and the arrangement position of the LED 14 can be freely determined. The degree can be increased. Also, in the finder according to the third embodiment, similarly to the finder according to the second embodiment, the FPC 16B is not bonded by the elastic restoring force of the FPC 16B and the FPC guide portion 18Bb.
Excellent in assembly workability because it can be in close contact with.

It is preferable to use a tape or the like having a metallic luster as the reflecting member 17 to be attached to the FPC 16B. However, when the LED 14 has a sufficient light amount, the reflecting member 17 is not used and the FPC 16B is not used. The surface may be a reflecting surface. In place of the reflection member 17, a so-called land portion is provided in which a conductor pattern (circuit pattern) formed on the FPC 16B is partially widened, and the surface of the land portion is covered with a chrome plating or gold plating layer to form a reflection surface. It is also possible to use In this case, F
It is preferable to make a hole in the coverlay film for lamination to the PC 16B so that the above-mentioned lands are not covered with the coverlay film because a high reflectance can be secured.

In the first to third embodiments described above, the display unit 10 is illuminated by the LED 14, but the irradiating means is not limited to the LED, but may use another light source. You may.

Although the example in which the display unit is incorporated in the viewfinder of the camera has been described, the display unit may be incorporated in the viewfinder of another optical device. Furthermore, even if the display unit is of a type that is directly viewed without passing through an optical system, by applying the present invention, light rays that are not originally involved in illuminating the display unit enter the inside of the display unit. It is possible to prevent desired internal reflection or the like. Thereby, the display contents can be made clear.

In the first to third embodiments described above, an example in which unnecessary illumination light is blocked by the FPC connected to the display unit 10 has been described. Is not limited to FPC. Further, light can be shielded by another member. For example, the shape of the housing or the like of the finder may be partially changed to shield light. Further, the transparent substrates 12 and 13 constituting the display unit may be glass substrates, or may be transparent films or transparent resin substrates. In addition, the description has been given of the case where a polymer-dispersed liquid crystal is used as a display unit. May transmit light in a state where is not applied. Further, a liquid crystal display unit of a different system having another diffusion means may be used in place of the polymer dispersed liquid crystal. Furthermore, a display unit combining different display types as described below may be used. That is, while providing an AF target frame composed of micro prisms on the surface of the transparent substrate 12 or 13,
The viewfinder field of view may be switched by the liquid crystal display unit in conjunction with switching the print type of the S camera or switching to the panorama mode in a camera using 135 type film. In the configuration described above, when the field of view is bright, the photographer can recognize the AF target mark as a black line, and the portion outside the shooting range in the viewfinder looks dark. When the field of view is dark, the photographer can recognize the AF target mark as a bright line by irradiating an LED or the like, and the portion of the viewfinder outside the shooting range looks bright.

In the correspondence between the above-described embodiment and the claims, the LED 14 serves as the illuminating means and the FPCs 16 and 16.
A or 16B constitutes a light shielding member and a circuit board, and the reflection member 17 constitutes a reflection means.

[0035]

As described above, according to the first aspect of the present invention, the light for illuminating the display unit is located on the observation surface side of the first and second transparent substrates. By providing a light-blocking member so as to enter from only the side of the transparent substrate to be light, of the light for illumination, light that does not contribute to the illumination of the display unit, inside the display unit,
Alternatively, it is possible to prevent the visibility of the display from being reduced due to reflection near the display unit. (2) According to the invention as set forth in claim 2, the first unit constituting the display unit disposed in the optical path of the finder optical system.
And arranging the illuminating means and the circuit board so as to be incident on the transparent substrate located on the observation surface side of the second transparent substrate, so that light which does not contribute to the illumination of the display unit is transmitted to the inside of the finder or the display unit. It is possible to suppress flare, ghost, and the like caused by being reflected by the finder, thereby lowering the appearance of the finder. (3) According to the third aspect of the present invention, the width of the circuit board and the display unit in the vicinity of the connection portion between the circuit board and the display unit are made larger than the width of the display unit. This makes it possible to more effectively suppress, by the circuit board, light that does not contribute to the illumination of the display unit, out of the light emitted from the illumination unit, from entering the inside of the display unit or the finder. (4) According to the invention described in claim 4, light emitted from the illumination means is reflected by the reflection means provided on the circuit board and guided to the display unit, whereby the display unit can be efficiently illuminated. It becomes possible. (5) According to the fifth aspect of the present invention, the display unit and the illuminating means have a unit structure integrally connected via the circuit board, so that the workability at the time of assembling the finder is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a finder according to a first embodiment.

FIG. 2 is a block diagram schematically showing an electric circuit of a camera in which the finder according to the first embodiment is incorporated.

FIG. 3 is an enlarged cross-sectional view showing the vicinity of a display unit disposition portion of the finder according to the first embodiment.

FIG. 4 is a diagram illustrating a state in which a display unit and a circuit board provided in the finder according to the first embodiment are connected;

FIG. 5 is an enlarged cross-sectional view showing the vicinity of a display unit disposition portion of a finder according to a second embodiment.

6A and 6B are diagrams illustrating a finder according to a third embodiment, in which FIG. 6A is an enlarged cross-sectional view showing the vicinity of a display unit disposition portion, and FIG. 6B is a diagram illustrating a circuit board and a display unit; It is a figure which shows a mode that is connected.

FIG. 7 is a sectional view of a finder according to a conventional technique.

FIG. 8 is an enlarged cross-sectional view showing the vicinity of a display unit disposing portion of a finder according to a conventional technique.

[Explanation of symbols]

 10, 110 Display unit 10a AF target mark 11, 111 Polymer dispersed liquid crystal 12, 13 Transparent substrate 14, 114 LED 16, 16A, 16B, 116 FPC 17 Reflecting member 20, 120 Objective optical system 21 to 24, 121 to 124 Objective lens 25, 125 roof prism 30, 130 eyepiece optical system 31, 131 pentaprism 32, 132 eyepiece 41 CPU 42 driver 112, 113 transparent glass substrate

Continued on the front page F term (reference) 2H018 AA02 BD06 BE02 2H091 FA14X FA21X FA21Z FA26X FA26Z FA34Y FA41X FD01 GA11 LA03 MA10 2H102 BB05 BB09 CA11 5C022 AA00 AB02 AB22 AC02 AC09 AC12 AC31 AC54 AC77

Claims (5)

[Claims] A first transparent substrate positioned on the side of the observation surface and a liquid crystal that changes into a state of transmitting or diffusing light in accordance with an applied voltage; A display unit sealed between second transparent substrates located on the back surface side; an illuminating unit for illuminating the display unit; and a luminous flux emitted from the illuminating unit toward the display unit. 2. A display device, comprising: (2) a shielding member that shields a light beam that is to enter the transparent substrate. 2. A liquid crystal display device comprising: a finder optical system; and a liquid crystal which changes into a state of diffusing or transmitting light according to an applied voltage, is sealed between first and second transparent substrates. A display unit in which a substrate is located on the eyepiece side of the finder optical system, and the second transparent substrate is located on the object side of the finder optical system, and is disposed in an optical path of the finder optical system; And a lighting unit for illuminating the display unit, and light emitted from the lighting unit will enter the optical path of the second transparent substrate and / or the finder optical system. The finder, wherein the illuminating means and the circuit board are disposed so as to block a light beam. 3. The finder according to claim 2, wherein the width of the circuit board and the width of the display unit in the vicinity of a connection portion between the circuit board and the display unit are determined by changing the width of the circuit board to the width of the display unit. A finder characterized by being larger than its dimensions. 4. The finder according to claim 2, further comprising a reflecting means provided on said circuit board for reflecting light emitted from said illuminating means, wherein said light is reflected by said reflecting means. A viewfinder for illuminating the display unit with the light. 5. The finder according to claim 2, wherein said illuminating means and said display unit have a unit structure integrally connected via said circuit board. Finders to do.