1. Field of the Invention
The present invention relates to an active matrix device which incorporates two-dimensional matrix pixels arranged to be operated by an active matrix method, and more particularly to an active matrix device which enables a switching operation to be performed without use of a MOS semiconductor switch section and which are arranged for use in a two-dimensional image pickup device, a light modulating device, an exposing device and a display device.
2. Description of the Related Art
An active matrix device is known which incorporates two-dimensional matrix pixels which are operated by the active matrix method. The active matrix device is used in, for example, a MOS 2D image pickup device, an LCD, a thin-film EL device and an organic EL device.
An active matrix device of a type for use in the MOS 2D image pickup device incorporates a photodetecting device and a MOS transistor for switching the photodetecting device, provided for each pixel section. In the foregoing case, the active matrix device causes the photodetecting device of each pixel to photoelectrically convert light of the image so as to accumulate charges. The charges are scanned through the MOS transistors in a row-sequential manner so that the accumulated charges are extracted. Thus, serial electric signals are extracted to the outside.
The active matrix device is, as described above, used in the light modulating device, the exposing device and the display device for the LCD, the thin-film EL device and the organic EL device. FIG. 30 shows an example of the active matrix LCD. As shown in FIG. 30, the active matrix device incorporates a light function device 1, such as the light modulating device, the exposure device or the display device, and a MOS transistor 3 which are provided for each of pixels disposed in a matrix configuration. In the foregoing case, the active matrix device applies scanning pulse voltages Vg in the row-sequential manner to simultaneously turn the connected MOS transistors 3 on. In synchronization with this, data signal voltages Vb are applied to the image electrodes in the column direction. Thus, scanning is performed through the MOS transistor 3 so that charges are accumulated in the static capacitor of each pixel. After scanning of one row has been completed, the MOS transistors 3 are turned off. Thus, the charges accumulated in the capacitors are maintained. In response to data signals based on the accumulated charges, the light function devices 1 are operated so that modulation of light, exposure or display is performed.
The conventional active matrix devices is not substantially affected by the number of rows (the number of scanning lines) and capable of moving precise image with an excellent quality.
However, the active matrix device incorporating the conventional MOS semiconductor transistor of a type made of a-Si:H (amorphous silicon), poly-Si (polycrystalline silicon) or c-Si (crystal silicon) has the foregoing problems.
That is, a large number of patterning processes must be performed. Moreover, a film forming process and a process for doping impurities peculiar to the process for manufacturing the semiconductor regions must be performed. Therefore, a severe design condition has been required. As a result, the throughput and manufacturing yield deteriorate. Thus, enlargement of a device formation area cannot easily be realized with a low cost.
An attempt has been made that the patterning step is completed by a (screen) printing process in order to enlarge the device formation area and reduce the producing cost. However, the accuracy and quality under present circumstances are not sufficient. Therefore, the printing process has not been realized yet.
A TFT incorporating a glass substrate on which a-Si:H or poly-Si is formed easily encounters dispersion of electrons and positive holes which move in the semiconductor owning to lattice defects (impurities, vacancies and dislocations). Therefore, only a poor carrier mobility is permitted. Thus, a display device in the form of a precise and large-area structure which must respond at higher response suffers from reduction in the speed of response. Although use of c-Si free from considerable dispersion enables the speed of response to be raised, c-Si cannot easily be formed on the glass substrate which is a low cost substrate.
It is required to form the semiconductor films, while maintaining severe process conditions. Espetially on forming a junction, the impurity densities of both semiconductor films between which the junction is formed, must severely administered.
Since the TFT is a semiconductor device, there arises a problem in that a malfunction occurs owning to incidence of light and introduction of water, oxygen, ions and an organic material from outside. To prevent the malfunction, a light shielding film and/or a protective layer must be formed. Therefore, the design conditions and processing conditions are furthermore limited.
The following mechanically-conductive switch has been disclosed in the following document:
(1) Micromechanical Membrane Switches on Silicon, IBM J, RES. DEVELOP., VOL. 23, No. 4, JULY 1979, pp. 376-385.
In the foregoing document, as shown in FIG. 31 which is a plan view showing a matrix device and FIG. 32 which is a cross sectional view taken along line Exe2x80x94E, a mechanical switch has been suggested. That is, the matrix device operating switches comprising the transistors and non-linear devices which are replaced by plate springs are employed. Each plate spring has either end which is secured is displaced by static electric force. Thus, contact/separation of the contact point provided for the leading end of the plate spring is used. In the foregoing structure, the plate spring is formed by a thin SiO2 film formed on a silicon substrate. The contact portion is made of a metal material such as gold.
Also a matrix type display device has been disclosed in the foregoing document. When a required data signal is written on a pixel electrode, a voltage is applied between a scanning-signal electrode and a P+ silicon layer disposed below the scanning-signal electrode. Thus, the contact electrode, the data-signal electrode and the pixel electrode are made electrical contact with one another. As a result, a required potential is applied from the data-signal electrode to the pixel electrode. When the voltage between the scanning-signal electrode and the P+ silicon layer is made to be zero, the contact of the foregoing electrode is separated. Thus, the data-signal electrode and the pixel electrode are made to be non-contact with each other. As a result, the potential of the pixel electrode can be maintained.
However, the mechanical switch, which has the above-mentioned structure in which either end is secured and, therefore, a cantilever spring structure is realized, has a possibility that mechanical bounds occur when contact/separation is performed. To prevent this, the structure and the operating voltage must delicately be adjusted. Therefore, the design freedom of the device is restrained.
As can be understood from the plan view, the plate spring requires a great area. Therefore, the rate of opening is reduced. To raise the speed of response by lowering the voltage for operating the switch, the length of the plate spring must be elongated. In this case, the foregoing problems become more critical.
Since the structure disclosed in the foregoing document incorporates the Si substrate, the structure is made to be an opaque structure with respect to visible light. Therefore, the foregoing structure is not suitable to serve as a transmission-type light modulating device. Moreover, enlargement of the area cannot easily be realized.
In addition, only the reflecting-type light modulating device has been disclosed. No description has been performed about the light-transmission-type modulating device and the light emitting device.
Another mechanically-conductive switch has been disclosed in the following patent.
(2) U.S. Pat. No. 4,681,403
In the foregoing patent, a switch for operating a matrix device has been disclosed which has a structure that a plate spring having an end which is secured or a plate spring having two ends which are secured is made of an electro-optical material, such as liquid crystal or an electrophoretic material.
FIG. 33 is a plan view showing the matrix device disclosed in the foregoing patent. FIG. 34 is a cross sectional view taken along line Fxe2x80x94F shown in FIG. 33. FIG. 35 is an equivalent circuit.
When the foregoing switch for operating the matrix device disclosed in the foregoing U.S. patent is operated to write a required data signal on a pixel electrode, a voltage is applied between each scanning-signal electrode and each data-signal electrode having the plate spring structure. As a result, the plate springs of the data-signal electrode are deflected so that the data-signal electrode and the pixel electrode are brought into electrical contact with each other. Thus, a required potential is supplied from the data-signal electrode to the pixel electrode. When the voltage between the scanning-signal electrode and the data-signal electrode is made to be zero, the data-signal electrode and the pixel electrode are brought to a non-contact state. As a result, the potential of the pixel electrode can be maintained.
The structure of the device disclosed in the foregoing U.S. patent incorporates the electro-optical material between two support substrates. Moreover, the foregoing switch is provided for either of the two substrates. In the foregoing case, introduction of fluid, such as liquid crystal, into the space between the two substrates sometimes causes a malfunction of the switch to occur. Moreover, the orientation of the liquid crystal is sometimes disordered. Although provision of a cover for fully covering the switch has been suggested, there arises a problem in that the process becomes too complicated and the area of the switch portion is undesirable enlarged owning to the provision of the cover.
The structure disclosed in the foregoing patent has the structure that the plate spring is electrically connected to the data-signal electrode. Therefore, a voltage must be applied to the position between the scanning-signal electrode and the data-signal electrode so as to operate the switch. Since the data-signal electrode is supplied with a required potential, the voltage which is supplied to the scanning-signal electrode must have an allowance. When the switch is made to be non-conductive or when scanning is not being performed, the structure of the switch and the voltage which must be applied must be considered to prevent a fact that the switch is made to be conductive regardless of the voltage of the data-signal electrode. The foregoing limitations excessively restrict the overall design freedom of the matrix device.
The static electric force for operating the switch depends on an electric field which is formed in a region in which the scanning-signal electrode and the data-signal electrode overlap. Therefore, satisfactory enlargement of the area of the region in which the two electrodes overlap for the purpose of enlarging the static electric force cannot easily be performed.
In view of the foregoing, an object of the present invention is to provide an active matrix device having a structure from which a semiconductor switch portion requiring a large number of patterning processes and severe design conditions and processing conditions is omitted so as to permit enlargement of the area and high-speed response and a light emitting device, a light modulating device, a photodetecting device, an exposing device and a display apparatus incorporating the foregoing active matrix device.
To achieve the foregoing object, a first aspect of a device is an active matrix device of the present invention, which comprises: a transparent substrate on which first scanning-signal electrode lines and data-signal electrode lines are allowed to intersect one another to one or two dimensionally dispose electrodes and structured such that at least one matrix operating means and a light function device are provided for each intersection, wherein the matrix operating means is a mechanically-conductive switch which is operated by static electric force.
The foregoing active matrix device has the structure that the light function device formed on the transparent substrate is operated by the mechanically-conductive switch having the mechanical structure. Thus, the light transmittance and the reflectance can be changed. Moreover, the manufacturing process and the structural materials can be simplified.
A second aspect of a device is an active matrix device according to the first aspect, wherein the mechanically-conductive switch has a thin flexible film which is moved by dint of a voltage which is applied between the first scanning-signal electrode and a second scanning-signal electrode disposed opposite to the first scanning-signal electrode to bring the data-signal electrode and a pixel electrode of the light function device into contact with each other.
In the foregoing active matrix device, the deflection of the thin flexible film is controlled in accordance with the voltage applied between the first and second scanning-signal electrodes so that the state of the switch is selectively set. A state of conduction between the data-signal electrode and the pixel electrode is determined for each pixel so that the state of each light function device is determined.
A third aspect of a device is an active matrix device for operating light function devices disposed one or two dimensionally by mechanically-conductive switches which are operated by static electric force, the active matrix device comprising: a plurality of parallel first scanning-signal electrodes in the form of stripes formed on a substrate; a plurality of parallel data-signal electrodes in the form of stripes disposed perpendicular to the first scanning-signal electrodes and formed at least at intersections with the first scanning-signal electrodes through insulating layers; common electrodes for pixel portions, light function devices and pixel electrodes which are sequentially laminated in a region on the substrate surrounded by the first scanning-signal electrodes and the data-signal electrodes; a plurality of support portions formed on the upper surfaces of the first scanning-signal electrodes; and thin flexible films and second scanning-signal electrodes disposed opposite to the first scanning-signal electrodes and laminated to be supported at the top ends of the support portions; and conductive films which are disposed opposite to the data-signal electrodes and the pixel electrodes such that contact is permitted through gaps and which are provided for the thin flexible films.
In the foregoing active matrix device, when the potential of the second scanning-signal electrode is the same as that of the first scanning-signal electrode, the thin flexible film is not supplied with the static electric force. Thus, the thin flexible film is not deflected. Therefore, the resistance between the data-signal electrode and the pixel electrode is infinitely large. Thus, the non-conductive state can be maintained. When the potential of the second scanning-signal electrode is different from that of the first scanning-signal electrode, the thin flexible film is deflected by the static electric force. As a result, the conductive film is brought into electrical contact with the data-signal electrode and the pixel electrode disposed below the thin flexible film in the direction of the deflection of the thin flexible film. As a result, the data-signal electrode and the pixel electrode are conducted to each other. When the voltage of each of the scanning-signal electrode is made to be zero, the thin flexible film is moved to the original position owning to the elastic force. As a result, the data-signal electrode and the pixel electrode are again brought to the non-conductive state.
A fourth aspect of a device is an active matrix device for operating light function devices disposed one or two dimensionally by mechanically-conductive switches which are operated by static electric force, the active matrix device comprising: a plurality of parallel first scanning-signal electrodes in the form of stripes formed on a substrate; a plurality of parallel data-signal electrodes in the form of stripes disposed perpendicular to the first scanning-signal electrodes and formed at least at intersections with the first scanning-signal electrodes through insulating layers such that the first scanning-signal electrodes are extended to substantially the overall region on the substrate surrounded by the first scanning-signal electrodes and the data-signal electrodes so that light function devices and pixel electrodes are sequentially laminated on the extended first scanning-signal electrodes; and a plurality of support portions formed on the insulating layers; and thin flexible films and second scanning-signal electrodes disposed opposite to the first scanning-signal electrodes and laminated to be supported at the top ends of the support portions; and conductive films which are disposed opposite to the data-signal electrodes and the pixel electrodes such that contact is permitted through gaps and which are provided for the thin flexible films.
In the foregoing active matrix device, when the potential of the second scanning-signal electrode has the same potential as that of the first scanning-signal electrode, the thin flexible film is not supplied with the static electric force. Thus, the thin flexible film is not deflected. Therefore, the resistance between the data-signal electrode and the pixel electrode is infinitely large. Thus, the non-conductive state can be maintained. When the potential of the second scanning-signal electrode is different from that of the first scanning-signal electrode, the thin flexible film is deflected by the static electric force. As a result, the conductive film is brought into electrical contact with the data-signal electrode and the pixel electrode disposed below the thin flexible film in the direction of the deflection of the thin flexible film. As a result, the data-signal electrode and the pixel electrode are conducted to each other. When the voltage of each of the scanning-signal electrode is made to be zero, the thin flexible film is moved to the original position owning to the elastic force. As a result, the data-signal electrode and the pixel electrode are again brought to the non-conductive state. Moreover, the common electrodes for the light function devices are the first scanning-signal electrode so that simplification of the process and cost reduction are permitted.
A fifth aspect of a device is an active matrix device for operating light function devices disposed one or two dimensionally by mechanically-conductive switches which are operated by static electric force, the active matrix device comprising: a plurality of parallel first scanning-signal electrodes in the form of stripes formed on a substrate; a plurality of parallel data-signal electrodes in the form of stripes disposed perpendicular to the first scanning-signal electrodes and formed at least at intersections with the first scanning-signal electrodes through insulating layers; pixel electrodes, light function devices and common electrodes for pixel portions which are sequentially laminated in a region on the substrate surrounded by the first scanning-signal electrodes and the data-signal electrodes; a plurality of support portions formed on the insulating layers; and thin flexible films and second scanning-signal electrodes disposed opposite to the first scanning-signal electrodes and laminated to be supported at the top ends of the support portions; and conductive films which are disposed opposite to the data-signal electrodes and the pixel electrodes such that contact is permitted through gaps and which are provided for the thin flexible films.
In the foregoing active matrix device, when the potential of the second scanning-signal electrode has the same potential as that of the first scanning-signal electrode, the thin flexible film is not supplied with the static electric force. Thus, the thin flexible film is not deflected. Therefore, the resistance between the data-signal electrode and the pixel electrode is infinitely large. Thus, the non-conductive state can be maintained. When the potential of the second scanning-signal electrode is different from that of the first scanning-signal electrode, the thin flexible film is deflected by the static electric force. As a result, the conductive film is brought into electrical contact with the data-signal electrode and the pixel electrode disposed below the thin flexible film in the direction of the deflection of the thin flexible film. As a result, the data-signal electrode and the pixel electrode are conducted to each other. When the voltage of each of the scanning-signal electrode is made to be zero, the thin flexible film is moved to the original position owning to the elastic force. As a result, the data-signal electrode and the pixel electrode are again brought to the non-conductive state. Thus, the active matrix device can be realized by a structure in which the pixel electrode is provided for the substrate and the common electrodes for pixels are disposed in the upper portion.
A sixth aspect of a device is an active matrix device according to the fifth aspect, which further comprises an upper substrate disposed opposite to the substrate, structured to hold the thin flexible films and the signal electrodes disposed on the substrate and joined to the upper surfaces of the common electrodes for the pixel portions.
In the foregoing active matrix device, when the potential of the second scanning-signal electrode has the same potential as that of the first scanning-signal electrode, the thin flexible film is not supplied with the static electric force. Thus, the thin flexible film is not deflected. Therefore, the resistance between the data-signal electrode and the pixel electrode is infinitely large. Thus, the non-conductive state can be maintained. When the potential of the second scanning-signal electrode is different from that of the first scanning-signal electrode, the thin flexible film is deflected by the static electric force. As a result, the conductive film is brought into electrical contact with the data-signal electrode and the pixel electrode disposed below the thin flexible film in the direction of the deflection of the thin flexible film. As a result, the data-signal electrode and the pixel electrode are conducted to each other. When the voltage of each of the scanning-signal electrode is made to be zero, the thin flexible film is moved to the original position owning to the elastic force. As a result, the data-signal electrode and the pixel electrode are again brought to the non-conductive state. Thus, the structure of the active matrix device can be realized in which the pixel electrode is provided for the lower substrate and the common electrodes for pixels are provided for the upper substrate such that the two substrates are positioned opposite to each other.
A seventh aspect of a device is an active matrix device, which comprises: light function devices disposed one or two dimensionally and arranged to be operated by mechanically-conductive switches which are operated by static electric force, wherein the thin flexible film switches and the light function devices are formed on individual surfaces and the mechanically-conductive switches and the light function devices are electrically connected to one another.
The foregoing active matrix device can be structured such that the mechanically-conductive switch is formed on either side of the substrate and the light function device is provided for another side. As a result, the utilization easiness and extensibility can be improved.
An eighth aspect of a device is an active matrix device which has a structure that a plurality of parallel first scanning-signal electrodes in the form of stripes are formed on the right side of a first substrate, a plurality of parallel data-signal electrodes in the form of stripes disposed perpendicular to the first scanning-signal electrodes are formed at least at intersections with the first scanning-signal electrodes through insulating layers, pixel electrodes, light function devices and common electrodes for pixel portions are sequentially laminated in a reverse side region of the first substrate surrounded by the first scanning-signal electrodes and the data-signal electrodes, a second substrate is, through a color filter, joined to the surface of the light function device opposite to the first substrate such that the second substrate is disposed opposite to the first substrate, a plurality of support portions are formed on the insulating layers of the first substrate, thin flexible films and second scanning-signal electrodes disposed opposite to the first scanning-signal electrodes are laminated to be supported at the top ends of the support portions, the right and reverse sides of the first substrate are conducted to each other to extend the pixel electrodes of the light function devices to positions adjacent to the data-signal electrodes, and conductive films disposed opposite to the data-signal electrodes and the pixel electrodes such that contact is permitted through gaps are provided for the thin flexible films.
In the foregoing active matrix device, when the potential of the second scanning-signal electrode has the same potential as that of the first scanning-signal electrode, the thin flexible film is not supplied with the static electric force. Thus, the thin flexible film is not deflected. Therefore, the resistance between the data-signal electrode and the pixel electrode is infinitely large. Thus, the non-conductive state can be maintained. When the potential of the second scanning-signal electrode is different from that of the first scanning-signal electrode, the thin flexible film is deflected by the static electric force. As a result, the conductive film is brought into electrical contact with the data-signal electrode and the pixel electrode disposed below the thin flexible film in the direction of the deflection of the thin flexible film. As a result, the data-signal electrode and the pixel electrode are conducted to each other. When the voltage of each of the scanning-signal electrode is made to be zero, the thin flexible film is moved to the original position owning to the elastic force. As a result, the data-signal electrode and the pixel electrode are again brought to the non-conductive state. When the pixel electrodes are conducted to the reverse side of the substrate by the through holes, the light function devices can be formed on-the reverse side of the substrate opposite to the mechanically-conductive switch. Since the second substrate is joined to the opposite surface of the substrate adjacent to the light modulating device, a space between the substrates is formed. Thus, a light modulating material can be introduced into the space. As a result, a low-cost and precise active matrix device having a large screen can be constituted.
An active matrix device according to the aspect 9 is characterized by a structure that the two ends of the thin flexible film are supported.
The foregoing active matrix device incorporates the thin flexible film which has the supported two ends. Therefore, a stable switching operation is permitted. As a result, occurrence of a mechanical bound can be prevented without a necessity of finely adjusting the operating voltage.
An active matrix device according to the aspect 10 is characterized by a structure that the thin flexible film having a length substantially corresponding to the length of one pixel is provided for each pixel.
The foregoing active matrix device is able to furthermore enlarge the area of the electrode. Thus, the static electric force can maximally be used and, therefore, the required operating voltage can be lowered.
An active matrix device according to the aspect 11 is characterized by a structure that the conductive film is made of metal.
Since the foregoing active matrix device incorporates the conductive film made of metal, the mobility of carriers can be enhanced and the speed of response can considerably be raised as compared with a conventional active matrix device incorporating a-Si:H, poly-Si or c-Si.
An active matrix device according to the aspect 12 is characterized by a structure that a plurality of the mechanically-conductive switches are provided for one pixel.
The foregoing active matrix device enables a normal switching operation to be performed if any one of the switches suffers a breakdown. Therefore, the stability of the operation can furthermore be improved.
An active matrix device according to the aspect 13 is characterized by a structure that the plural mechanically-conductive switches are connected in series.
If either switch encounters short circuit, the foregoing active matrix device can be operated by another switch.
An active matrix device according to the aspect 14 is characterized in that the plural mechanically-conductive switches are connected in parallel.
If either switch encounters a defect in the contact operation thereof, another switch enables the operation of the foregoing active matrix device to be performed.
An active matrix device according to the aspect 15 is characterized by a structure that the mechanically-conductive switch is sealed in a rare gas atmosphere.
The foregoing active matrix device is able to effectively prevent switching discharge.
An active matrix device according to the aspect 16 is characterized by a structure that the mechanically-conductive switch incorporates a resistor for preventing switching discharge.
The foregoing active matrix device incorporating the resistor for preventing switching discharge is able to easily prevent switching discharge with a low cost.
An active matrix device according to the aspect 17 is characterized by a structure that the mechanically-conductive switch is supplied with a cleaning electric current at predetermined intervals of time.
The foregoing active matrix device is able to easily break and remove the oxide film on the contact portion of the mechanically-conductive switch.
A light emitting device according to the aspect 18 comprises a light function device of the active matrix device according to any one of aspects 1 to 17, wherein the light function device serves as the light emitting device.
The foregoing light emitting device causes display to be realized with light emitted from the light emitting device so that high speed display by dint of light is realized.
A light modulating device according to the aspect 19 comprises: a light function device of the active matrix device according to any one of claims 1 to 17, wherein the light function device serves as the light modulating device.
The foregoing light modulating device is able to selectively set a transmission/non-transmission state by the operation of the light modulating device.
A light modulating device according to the aspect 20 is characterized by a structure that the light modulating device is liquid crystal.
The foregoing light modulating device has the structure that the light modulating device is liquid crystal. Therefore, the light modulating device can be constituted by using a conventional technique.
A light modulating device according to the aspect 21 is characterized by a structure that the light modulating device is a device for modulating light by deforming a thin flexible film with static electric force.
The light modulating device has the structure that the thin flexible film is deflected by static electric force. Therefore, a mechanically-conductive switch using the static electric force can be realized by a simple structure. In the foregoing case, all of the operation portions can be realized by mechanical structures. Therefore, the manufacturing process and the materials can be simplified. Moreover, an electro-mechanical light modulating device can be realized in which the movable portions are moved by static electric force to change the light transmittance.
A light modulating device according to the aspect 22 is characterized by a structure that the light function device performs light modulation by applying an electric field between each of the pixel electrodes and each of the electrodes disposed opposite to the pixel electrodes to deflect the thin flexible films provided for the light function devices so as to generate an optical interference effect of a multilayered film.
In the foregoing light modulating device, the thin flexible film interrupts the optical path if no voltage is applied between the electrodes. If a voltage is applied between the electrodes, the thin flexible film is deflected to change the optical lengths of the two films. As a result, an optical interference effect of the multilayered film is generated. As a result, light modulation is permitted.
According to another aspect according to the aspect 23, there is provided a photodetecting device comprising: a light function device of the active matrix device according to any one of claims 1 to 17, wherein the light function device serves as the photodetecting device.
The foregoing photodetecting device has the structure that light of an image is photoelectrically converted by the photodetecting device of each pixel to accumulate charges. Then, the accumulated charges are scanned through the mechanically-conductive switch in the row-sequential manner to extract the accumulated charges. Thus, light of the image can be converted into a serial electric signal.
According to another aspect according to the aspect 24, there is provided an exposing device comprising: a light function device of the active matrix device according to any one of claims 1 to 17, wherein the light function device serves as the exposing device.
The foregoing exposing device is able to modulate ultraviolet rays emitted from, for example, a plane light source to expose an ultraviolet-ray sensitive material.
According to another aspect according to the aspect 25, there is provided a display apparatus comprising: a light function device of the active matrix device according to any one of aspects 1 to 17, wherein the light function device serves as the light modulating device, and the light modulating device modulates light emitted from a plane light source to cause a fluorescent member to emit light with modulated light.
In foregoing display apparatus, the fluorescent member is caused to emit light for display by emitted light so that high-speed display with light is realized.
A display apparatus according to the aspect 26 is characterized by a structure that the plane light source emits ultraviolet rays.
The foregoing display apparatus is permitted to use a relatively low-cost and low-pressure mercury lamp or the like. Therefore, the cost of the apparatus can be reduced.