Patent Application
20110018909
The present invention relates to an image display with a function for transmitting light from a subject to be observed, which enables an observer to view a subject to be observed located on the rear side of a display element through the display element and which can display information provided to the observer.
As a finder device for a camera, a finder device including a dispersion (diffusion) liquid crystal display panel is known (for example, see Patent Documents 1 and 2).
Inside the camera main body 300, a liquid crystal display panel 312 driven by a drive circuit 316 is provided in the course of the optical path of light reflected by the mirror 311. The liquid crystal display panel 312 is configured such that a liquid crystal element is sandwiched between a pair of transparent substrates with electrodes. The liquid crystal display panel 312 is brought into a light transmitting state when a voltage is applied between the substrates, and is brought into a light scattering state when no voltage is applied.
A photographer who photographs a subject to be observed by using a camera performs photographing while looking through the see-through window 315. The photographer operates a switch (not shown) provided in the camera main body 300 so as to perform mode setting. A CPU (not shown) provided in the camera main body 300 controls the drive circuit 316 in accordance with a set mode such that a voltage is not applied between electrodes in a predetermined display target area of the liquid crystal display panel 312. As a result, as illustrated in an explanatory view of
Patent Document 1: JP-A-2004-212792
Patent Document 2: JP-A-2000-75393
However, the finder device using the above-described liquid crystal display panel 312 has the following problems. First, it is necessary to apply a voltage between the substrates so as to bring the liquid crystal display panel 312 into the light transmitting state, causing an increase in power consumption of the camera. In general, since an electrical circuit provided in the camera is driven by a battery, the available period of the battery is shortened. Further, when a camera which is provided with the finder device using the above-described liquid crystal display panel 312 is displayed at the front of a store such that a user can access the camera, if the camera is powered on, the battery runs down. For this reason, the camera is displayed in a state of being powered-off. When this happens, when the user looks through the see-through window 315 of the camera, the user may view nothing and may distrust the quality of the camera.
In the liquid crystal display panel 312, electrodes (in the example of
Accordingly, an object of the invention is to provide an image display with a function for transmitting light from a subject to be observed (hereinafter, referred to as a light transmitting function) which can reduce power consumption and has a good appearance of a display surface.
An image display with a function for transmitting light from a subject to be observed according to the invention includes: a display element which includes a pair of transparent substrates with electrodes, and a liquid crystal layer which is sandwiched between the pair of substrates with electrodes and is capable of being in a light transmitting state and a light scattering state, the display element being brought into the light transmitting state when no voltage is applied and being brought into the light scattering state when a voltage is applied; a light source which inputs light substantially parallel with the surface of the liquid crystal layer (including light completely parallel with the surface of the liquid crystal layer) into the liquid crystal layer; and a timing control circuit which brings at least a part of the display surface of the display element into the light scattering state or the light transmitting state in conjunction with the state of light emission into the liquid crystal layer of the light source in the presence of external light.
The light source may produce one light source color and a frame frequency thereof may be equal to or greater than 15 Hz.
If the light source color is red, a specific display portion of the display element is brought into the light scattering state in conjunction with light emission, and the portion becomes a display color of red, improving visibility for the observer.
The light source may produce one light source color, the frame frequency of the light source color may be equal to or greater than 15 Hz, the ratio of a light emission period in one frame may be equal to or smaller than ⅓, and the timing control circuit may bring at least a part of the display surface of the display element into the light scattering state in conjunction with a light non-emission period. Thus, the light non-emission period can be sufficiently secured, and a good display color according to external light can be obtained. For the use of an optical system in which at least a part of external light is blocked by the portion in the light scattering state, such as a finder for a single-lens reflex camera, in the light non-emission period, a period in which a specific portion of the display element is in the light scattering state is adjusted, such that halftone display can be carried out from perfect black display to light-black. As a result, visibility for the observer can be improved, and expressive display can be carried out on the display surface.
The light source may sequentially produce two or more light source colors, the frame frequency of each light source color may be equal to or greater than 15 Hz, and the timing control circuit brings at least a part of the display surface of the display element into the light scattering state or the light transmitting state in conjunction with the state of light emission of one light source color or a plurality of light source colors to obtain a display color according to one light source color or a plurality of light source colors.
The light source can produce, for example, red, blue, and green individually. The image display may include, at different display timing in a single display portion, display in which the display color is a single color and display in which the display color is multi-color.
It is preferable that a light guide portion be provided between the light source and the display element to spread light emitted from the light source from one end to the other end at the lateral part of the liquid crystal layer.
It is preferable that the frame frequency of the light source color is equal to or greater than 30 Hz.
The image display with a function for transmitting light from a subject to be observed according to the invention can be applied to, for example, a finder device for a camera, an optical microscope, and binoculars.
According to the invention, it is possible to provide an image display with a function for transmitting light from a subject to be observed, which can reduce power consumption and has a good appearance of a display surface.
a) to 3(e) are explanatory views illustrating a curable compound which can be used in a display element.
Hereinafter, an embodiment of the invention will be described with reference to the drawings. First, a display method which is used in an image display according to the invention will be described. In the image display according to the invention, a field sequential color method is used in which color display is obtained by combining a liquid crystal display panel and a light source which selectively produces red, blue, and green, in the presence of external light. According to the field sequential color method, image according to each produced color is sequentially displayed on the liquid crystal panel to start drive. Thus, the liquid crystal panel has to have a sufficiently high response speed.
According to the field sequential color method, for example, one color has to be displayed in a period which is ⅓ of one field. For this reason, for example, when display at 60 fields/second is performed, the time available for display is about 5 ms (milliseconds). Thus, liquid crystal itself is required to have a response time shorter than 5 ms. As liquid crystal for achieving high-speed response, ferroelectric liquid crystal, antiferroelectric liquid crystal, narrow-gap nematic liquid crystal, OCB-mode liquid crystal, and the like are known.
However, in a display element which uses such liquid crystal, a polarizing plate is used. For this reason, transmittance is degraded, and when a viewer looks the rear side through the display element, visibility is degraded. Accordingly, in the image display according to the invention, as described below, a liquid crystal display element is used which can be in a light transmitting state and a light scattering state, and can reduce a response time required for switching from the light transmitting state to the light scattering state at normal temperature (for example, 25° C.) and a response time required for switching from the light scattering state to the light transmitting state at normal temperature shorter than 5 ms. Although the response speed of liquid crystal generally decreases at low temperature, it is possible to cope with a temperature range appropriate to the purpose through temperature compensation.
If light is input from the light source 2 to the liquid crystal layer of the display element 1, a scattering portion of the liquid crystal layer scatters light and is recognized as bright by an observer 3. If the color of light of the light source 2 is changed to an arbitrary color, characters or figures can be displayed with the arbitrary color. The light source 2 is provided at the edge of the display element 1 to input light to the liquid crystal layer. A light guide portion is preferably provided between the light source 2 and the display element 1 to diffuse light. In the invention, the term “transparent” means a state where transmittance of light is equal to or greater than 50%, and preferably, equal to or greater than 80%. In the case of the transparence state, the observer 3 can look a subject to be observed through the display element 1. That is, the image display 10 has a function for transmitting light from the subject to be observed (light transmitting function).
The materials for the substrates 101 and 108 are not particularly limited insofar as transparency can be secured. As the substrates 101 and 108, glass substrates or plastic substrates may be used. The display element 1 does not have to have a planar shape, and may be curved.
For the transparent electrodes 102 and 107 formed on the substrates 101 and 108, transparent electrode materials including metal oxides, such as ITO (indium oxide-tin oxide), may be used. Hereinafter, the substrates 101 and 108 with the transparent electrodes 102 and 107 are referred to as electrode-attached substrates.
The liquid crystal layer 104 which can be in the light transmitting state and the light scattering state is preferably a liquid crystal layer which is formed as a liquid crystal/polymer complex by sandwiching a composition (hereinafter, referred to as an uncured composition) containing liquid crystal and a curable compound which is soluble in liquid crystal, between a pair of transparent substrates with electrodes, and curing the curable compound by using heat, ultraviolet rays, electronic beams, or the like. Hereinafter, liquid crystal which is made of a complex of liquid crystal and a polymer is also called a liquid crystal/polymer complex.
Liquid crystal for use in the liquid crystal/polymer complex may have positive or negative dielectric anisotropy. Meanwhile, in order to reduce the response time required for switching between the light transmitting state and the light scattering state, liquid crystal having low viscosity and negative dielectric anisotropy is preferably used. As liquid crystal, a compound which is not curable is used. The curable compound may have liquid crystallinity.
When liquid crystal having negative dielectric anisotropy is used, if processing is carried out for the electrode-attached substrates such that the pretilt angle of liquid crystal molecules in contact with the liquid crystal layer 104 is equal to or greater than 60 degrees with respect to the substrate surface, preferably, alignment defects can be reduced, and transparency can be improved. In this case, rubbing treatment may not be carried out. The pretilt angle is preferably equal to or greater than 70 degrees. With regard to the pretilt angle, the direction perpendicular to the substrate surface is defined as 90 degrees.
Liquid crystal which constitutes the liquid crystal/polymer complex for forming the liquid crystal layer 104 may be appropriately selected from known liquid crystal. By using the electrode-attached substrates in which the pretilt angle of the uncured composition can be controlled by the alignment films 103 and 106, liquid crystal having positive dielectric anisotropy or liquid crystal having negative dielectric anisotropy may be used. Meanwhile, from the viewpoint of higher transparency or response speed, liquid crystal having negative dielectric anisotropy is preferably used. The alignment films may be subjected to rubbing treatment. Further, in order to reduce the drive voltage, the absolute value of dielectric anisotropy preferably is preferably large.
The curable compound which constitutes the liquid crystal/polymer complex preferably has transparency. Further, if liquid crystal and the curable compound are separated from each other such that only liquid crystal responds when a voltage is applied after being cured, preferably, the drive voltage can be decreased.
According to the invention, of curable compounds which are soluble in liquid crystal, a curable compound is used which can control the alignment state of a mixture of liquid crystal and a curable compound when being uncured, and can maintain high transparency when being cured.
As the curable compound, a compound represented by Expression (1) or a compound represented by Expression (2) may be exemplified.
A1-O—(R1)m—O—Z—O—(R2)nO-A (1)
A3-(OR3)o—O—Z′—O—(R4O)p-A4 (2)
Here, A1, A2, A3, and A4 represent an acryloyl group, a methacryloyl group, a glycidyl group, or an allyl group as a curing region independently; R1, R2, R3, and R4 represent an alkylene group having a carbon number of 2 to 6 independently; Z and Z′ represent a divalent mesogenic structure portion independently; m, n, o, and p represent an integer of 1 to 10 independently. The term “independently” means that a combination is arbitrary and any combination is available.
In Expressions (1) and (2), an oxyalkylene structure having high molecular mobility which contains R1, R2, R3, and R4 is introduced between the mesogenic structures Z and Z′ and the cured regions A1, A2, A3, and A4, such that molecular mobility of the curing regions can be improved in the course of curing and curing can be sufficiently carried out in a short time.
In Expressions (1) and (2), for the curing regions A1, A2, A3, and A4, any of the above-described photo-curable or thermosetting functional groups may be used. Of these, an acryloyl group or a methacryloyl which is appropriate to photo-curing is preferably used since the temperature at the time of curing can be controlled.
In Expressions (1) and (2), the carbon number of each of R1, R2, R3 and R4 is preferably 1 to 6 from the viewpoint of molecular mobility. An ethylene group having a carbon number of 2 and a propylene group having a carbon number of 3 are more preferably used.
In Expressions (1) and (2), as the mesogenic structure portions Z and Z′, a linked polyphenylene group of 1,4-phenylene group may be exemplified. A portion of the 1,4-phenylene group or the entire 1,4-phenylene group may be substituted with a 1,4-cyclohexylene group. A part or all of hydrogen atoms of the 1,4-phenylene group or the substituted 1,4-cyclohexylene group may be substituted with a substituent group having a carbon number of 1 to 2, such as an alkyl group, halogen atoms, a carboxyl group, or an alkoxycarbonyl group.
Preferred examples of the mesogenic structure portions Z and Z′ include a biphenylene group in which two 1,4-phenylene groups are linked (hereinafter, a biphenylene group in which two 1,4-phenylene groups are linked is also referred to as a 4,4-biphenylene group), a terphenylene group in which three 1,4-phenylene groups are linked, and biphenylene groups in which 1 to 4 hydrogen atoms are substituted with an alkyl group, fluorine atoms, chlorine atoms, or a carboxyl group having a carbon number of 1 to 2. The 4,4-biphenylene group having no substituent group is most preferably used. Bonds between 1,4-phenylene groups or 1,4-cyclohexylene groups constituting the mesogenic structure portion may be all single bonds or the following bonds.
In Expressions (1) and (2), m, n, o, and p are preferably 1 to 10 independently, and more preferably, 1 to 4. This is because, if m, n, o, and p are very large, compatibility with liquid crystal is degraded, and transparency of the electro-optical element after curing is degraded.
A composition containing liquid crystal and a curable compound may contain a curing catalyst. In the case of photo-curing, a photopolymerization initiator, such as benzoin ether series, acetophenone series, or phosphine oxide series, which is generally in photo-curable resin, may be used. In the case of thermosetting, a curing aid, such as peroxide series, thiol series, amine series, or acid anhydride, may be used in accordance with the type of the curing region. If necessary, a curing aid, such as amine series, may be used.
The content of the curing catalyst is preferably equal to or smaller than 20% by mass of the contained curable compound. When a high molecular weight or high specific resistance of cured resin after curing is required, the content of the curing catalyst is preferably 0.1 to 5% by mass.
In an uncured composition, the total amount of the curable compound is preferably 0.1 to 20% by mass with respect to the liquid crystal composition. If the total amount of the curable compound is smaller than 0.1% by mass, the liquid crystal phase cannot be divided into a domain structure having a shape more effective for a cured material, and a desired transmission-scattering characteristic cannot be obtained. Meanwhile, if the total amount of the curable compound exceeds 20% by mass, similarly to the known liquid crystal/cured material complex, the haze value in the transmitting state is likely to be increased. More preferably, the content of the cured material in the liquid crystal composition is 0.5 to 15% by mass, such that scattering intensity in the light scattering state can be increased, and a voltage value for transmission-scattering switching can be decreased.
As the processing method of aligning liquid crystal molecules such that the pretilt angle is equal to or greater than 60 degrees with respect to the substrate surface, a method is used in which a vertical alignment agent is used. As the method using a vertical alignment agent, for example, there is a method using a surfactant agent, a method in which the substrate interface is processed by a silane coupling agent containing an alkyl group or a fluoroalkyl group, or a method in which a commercially available vertical alignment agent, such as SE1211 manufactured by Nissan Chemical Industries, Ltd. or JALS-682-R3 manufactured by JSR, is used. In order to bring a state where liquid crystal molecules are tilted from the vertical alignment state to an arbitrary direction, any known method may be used. The vertical alignment agent may be subjected to rubbing. Further, a method may be used in which slits are provided in the transparent electrodes 101 and 107 or triangular columns are arranged on the electrodes 101 and 107, such that a voltage is applied obliquely with respect to the substrates 101 and 108. A device for tilting the liquid crystal molecules in a specific direction may not be provided.
The thickness of the liquid crystal layer 104 between the two substrates 101 and 108 can be defined by spacers or the like. The thickness of the liquid crystal layer 104 is preferably 1 to 50 and more preferably, 3 to 30 μm. If the thickness of the liquid crystal layer 104 is excessively small, contrast is degraded. If the thickness of the liquid crystal layer 104 is excessively large, undesirably, there are many cases where the drive voltage increasingly tends to be increased.
For the seal layer 105, any known resin may be used insofar as resin has high transparency. If resin having high transparency is used, transparency increases over the entire surface of the display element, and a state where characters or figures seem to be floated in the air is highlighted. For example, when glass substrates are used as the substrates 101 and 108, if epoxy resin or acrylic resin having a refractive index similar to the refractive index of glass is used, a state where transparent glass seems to be floated in the air can be realized. In the case of a use method in which a seal portion is not usually viewed by an observer, in particular, the seal layer has to be transparent.
In the image display 10 produced as described above, a very high response speed can be realized such that the response time between the light transmitting state and the light scattering state of a display image is shorter than 5 ms around at least normal temperature. Further, good viewing angle dependency is obtained, and an excellent light transmitting state can be obtained even when being viewed obliquely, as compared with a scattering/transmitting mode by the known dispersion liquid crystal element. For example, when a complex having the above-described configuration, which contains the curable compound and liquid crystal, is used, it is possible to eliminate a haze mostly even when being viewed obliquely at 40 degrees from the perpendicular state.
As the size of the display element 1, the length of the diagonal is about 1 cm to about 3 m. Any size of display element may be used.
In the image display 10, a plurality of display elements 1 may be used.
Further, in order to increase impact resistance of the display element 1, the upper and lower substrates 101 and 108 may be fixed.
Reflection prevention films or ultraviolet shielding films are preferably provided on the front and rear surfaces of the display element 1. For example, AR coat (low reflection coat) treatment using a dielectric multilayer film, such as SiO2 or TiO2, is performed on the front and rear surfaces of the display element 1, such that reflection of external light on the substrate surface can be reduced and contrast can be further improved.
As the light source 2, a light source, such as an LED, is used in which time-division control is possible. Meanwhile, in implementing the field sequential color method, for example, a method in which light sources of red, green, and blue are sequentially turned on, or a method in which a produced color is sequentially changed by combining color filters with respect to white light.
As shown in the enlarged view of the image display 10 of
In the example of
Next, the relationship between the light source 2 and drive of the display element 1 in the field sequential color method used in the image display 10 of the invention will be described with reference to a timing diagram of
It is assumed that, in the display element 1 of
The cycle of one frame corresponding to the turn-on periods of the light sources of three colors is preferably equal to or smaller than (1/15) seconds. That is, the frame frequency corresponding to the frequency of turn-on of each of the light sources of three colors is equal to or greater than 15 Hz. This is because, if the frame frequency is smaller than 15 Hz, flickering is likely to be viewed. The frame frequency is more preferably equal to or greater than 30 Hz, and still more preferably, equal to or greater than 60 Hz.
The display element 1 produced as described above is brought into the light scattering state when a predetermined voltage (for example, 60 V) is applied to the liquid crystal layer 104, which can be in the light transmitting state and the light scattering state, and is brought into the light transmitting state when no voltage is applied to the liquid crystal layer 104. Thus, in
Hereinafter, signals for generating timing of light source ON and light source OFF shown in
The transparent electrodes 1021, 1022, and 1023 correspond to the transparent electrodes 102 shown in
Although in
The timing control circuit 201 turns on a red light source (red LED) 31, a green light source (green LED) 32, and a blue light source (blue LED) 33 in the light source 2 with timing illustrated in
Although the drive voltage which is applied to the transparent electrodes 1021 and the transparent electrodes 1071 is, for example, ±30 V, alternating-current drive is preferably carried out while changing positive and negative of the drive voltage of the transparent electrodes 1021 and the drive voltage of the transparent electrodes 1071 with predetermined timing. However, since high frequency is one of causes for an increase in power consumption, the drive voltage is preferably set in consideration of appropriate balance.
The display portions 7 and 9 are formed by a plurality of segments. In a state of scattering signal ON shown in
In the display element 1, when a TFT element is used as a drive element, if the scattering signal is in the OFF state and the display element 1 is in the transparence state, the viewer is likely to view the TFT element. However, in this embodiment, the display element 1 does not include an active element, such as a TFT element, and is driven statically, thus there is no case where an object which does not have to be viewed originally is viewed in the transparence state.
Although production of RGB can be switched substantially simultaneously with input of the switching signal, the display portions 7, 8, and 9 cannot be changed immediately with respect to input of the scattering signal or transparence signal (specifically, start of application of the drive voltage to the transparent electrodes 1021, 1022, 1023, 1071, 1072, and 1073 or erasure of the drive voltage). This is because responsiveness of the display element has a delay. If the light scattering state is maintained other than a desired light source color, color mixture occurs, causing color deterioration. For this reason, it is necessary to prevent occurrence of a situation where the light scattering state is maintained other than a desired light source color. Therefore, the timing of switching signal input to the light source and the timing of signal input (start of application of the drive voltage or erasure of the drive voltage) to the display portions 7, 8, and 9 are preferably deviated from each other.
For example, as shown in
If the OFF period shown in
As shown in
As shown in
The use of the field sequential color method makes it possible to simultaneously obtain desired produced colors in the respective areas of the display element 1. For example, the mark 8 (see
When the three light sources 31, 32, and 33 are provided, and the display portions are brought into the light scattering state, the display portions of the display element 1 can produce seven colors of red, RG mixed color, RB mixed color, RGB mixed color (white), green, GB mixed color, and blue. That is, if transparence when the light sources are not turned on and the display portions are in the light transmitting state is included, eight colors can be produced. Further, if black due to external light when the light sources are not turned on and the display portions in the light scattering state is include, nine colors can be produced. If the mixed color is called multi-color, single-color display and multi-color display can be simultaneously performed in different display portions of the single display element 1.
Display in which the display color is a single color and display in which the display color is multi-color may be performed with different timing in the single display portion. For example, the display portion 7 may produce red in one period and may produce RB mixed color in another period. If display in which the display color is a single color and display in which the display color is multi-color are carried out with different timing, for example, the mark 7 indicating the remaining battery level may be displayed with different colors in accordance with the remaining battery level, or the mark indicating the focus area may be displayed green to indicate in-focus and may be displayed red to indicate out-of-focus.
Although in the examples of
Although in this embodiment, a case has been described where the three light sources 31, 32, and 33 are provided as the light source 2, two light sources which produce different light source colors may be used. When two light sources are used, multiple display colors based on light source colors can be obtained in the display element 1 by the field sequential color method.
Although in the examples of
As shown in
The ratio of the light emission period in one frame is preferably equal to or smaller than ⅓. If the light emission period exceeds ⅓, red display has no problem, but black display is light and scarcely viewed as black. Further, the ratio of the light emission period is more preferably equal to or smaller than ⅙. If the ratio of the light emission period is greater than ⅙, black display substantially has no problem, but there is a possibility that the irradiation time is lacking in accordance with irradiation intensity of the light source, red display is light and scarcely viewed as red.
When a mark indicating a focus area shown in
The image display 10 according to the invention may be widely applied to an optical microscope or binoculars, in addition to the finder device for the camera, for the purpose of superimposingly displaying information through the see-through for the observer when the observer 3 observes a subject to be observed through the see-through window or the like.
As shown in
As shown in
Although surface reflection is repeated within the light guide portion 4, when a reflecting element is attached to the front or rear surface of the light guide portion 4, it is considered that scattering occurs and light leaks outside the light guide portion 4 before light reaches the display element 1. Thus, as shown in
Hereinafter, examples of the invention will be described. In the examples, the term “parts” means parts by mass.
Eighty-five parts of nematic liquid crystal (Tc=98° C., Δ∈=−5.6, Δn=0.220) having negative dielectric anisotropy, 12.5 parts of a bifunctional curable compound shown in
A liquid crystal cell was produced as follows. A pair of substrates 101 and 108 on which vertical alignment polyimide thin films 103 and 106 were formed on the transparent electrodes 102 and 107 were bonded to each other by epoxy resin (peripheral seal) printed on the four sides at a width of about 1 mm through a small amount of dispersed resin beads (diameter 6 μm) such that the vertical alignment polyimide thin films 103 and 106 were arranged to be opposite each other. Thus, a liquid crystal cell was formed. Next, the mixed liquid was filled in the liquid crystal cell.
In a state where the liquid crystal cell was maintained at 33° C., ultraviolet rays were irradiated at 3 mW/cm2 from above and at about 3 mW/cm2 from below for 10 minutes by an HgXe lamp having a main wavelength of about 365 nm. Thus, a display element in which a liquid crystal layer made of a liquid crystal/polymer complex was formed between the substrates was obtained.
The display element obtained as described above was in a uniform transparence state in a state where no voltage was applied. If a 200 Hz, 60 V square-wave voltage was applied to display element, the display element was changed as being clouded. Transmittance was measured by a Schlieren optical system (the F value of the optical value was 11.5, and the converging angle was 5°) using a measurement light source having a half bandwidth of about 20 nm with a center wavelength of 530 nm. In a state where no voltage is applied, transmittance was 80%, and the value of contrast obtained by dividing the value by transmittance when 60 Vrms was applied was 16.
Three LED light sources of red (R), green (G), and blue (B) were used as the light source 2. The relationship shown in
The display element 1 was placed as the display element of the image display 10 provided in the finder device for the camera shown in
At the lower end of
Eighty-five parts of nematic liquid crystal (Tc=98° C., Δ∈=−5.6, Δn=0.220) having negative dielectric anisotropy, 12.5 parts of a bifunctional curable compound shown in
A liquid crystal cell was produced as follows. A pair of substrates 101 and 108 on which vertical alignment polyimide thin films 103 and 106 were formed on the transparent electrodes 102 and 107 were bonded to each other by epoxy resin (peripheral seal) printed on the four sides at a width of about 1 mm through a small amount of dispersed resin beads (diameter 6 μm) such that the vertical alignment polyimide thin films 103 and 106 are arranged to be opposite each other. Thus, a liquid crystal cell was formed. Next, the mixed liquid was filled in the liquid crystal cell.
In a state where the liquid crystal cell was maintained at 33° C., ultraviolet rays were irradiated at 10 mW/cm2 from above and at about 10 mW/cm2 from below for 10 minutes by an HgXe lamp having a main wavelength of about 365 nm. Thus, a display element in which a liquid crystal layer made of a liquid crystal/polymer complex was formed between the substrates was obtained.
The display element obtained as described above was in a uniform transparence state in a state where no voltage was applied. If a 200 Hz, 60 V square-wave voltage was applied to the display element, the display element was changed as being clouded. Transmittance was measured by a Schlieren optical system (the F value of the optical value was 11.5, and the converging angle was 5°) using a measurement light source having a half bandwidth of about 20 nm with a center wavelength of 530 nm. In a state where no voltage is applied, transmittance was 80%, and the value of contrast obtained by dividing the value by transmittance when 60 Vrms was applied was 18.
Three LED light sources of red (R), green (G), and blue (B) were used as the light source 2. The relationship shown in
The display element 1 was placed as the display element of the image display 10 provided in the finder device for the camera shown in
At the lower end of
Similarly to Example 2, a display element in which a liquid crystal layer made of a liquid crystal/polymer complex was formed between the substrates was produced. A single LED light source of red (R) only was used as the light source 2. The relationship shown in
The display element 1 was placed as the display element of the image display 10 provided in the finder device for the camera shown in
Similarly to Example 2, a display element in which a liquid crystal layer made of a liquid crystal/polymer complex was formed between the substrates was produced. A single LED light source of red (R) only was used as the light source 2. The relationship shown in
The display element 1 was placed as the display element of the image display 10 provided in the finder device for the camera shown in
Similarly to Example 2, a display element in which a liquid crystal layer made of a liquid crystal/polymer complex was formed between the substrates was produced. A single LED light source of red (R) only was sued as the light source 2. The relationship shown in
The display element 1 is placed as the display element of the image display 10 provided in the finder device for the camera shown in
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
This application is based on Japanese Patent Application No. 2008-071614 filed on Mar. 19, 2008, the entirety of which is incorporated herein by way of reference. All references cited herein are incorporated by reference herein in their entirety.
In the image display of the invention, two or more colors including black which are viewed beyond the eye lens can be produced simultaneously in an arbitrary portion of the display element. Therefore, display can be realized such that a non-display portion can be transparent and a background can be viewed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-071614 | Mar 2008 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP09/55482 | Mar 2009 | US |
| Child | 12885022 | US |
