JPH08271986A - Display device - Google Patents

Abstract

PURPOSE: To enhance the brightness of a whole display surface and to uniformize it by arranging a liquid crystal display unit at a position facing a linear light source and adjacent to the linear light source and constituting it so that it is closely brought into contact with the incident surface of an optical fiber screen. CONSTITUTION: A high-luminance metal halide lamp 52 is arranged perpendicularly on the inside of a light source casing 51 and a reflector 53 efficiently guiding light emitted from the lamp 52 downward is provided on the inside of the casing 51. Then, an IR cut mirror 54 inclined by 45 deg. is provided under the lamp 52. Besides, a UV cut filter is installed at the exit window of the casing 51. The liquid crystal display unit 55 is installed at a position adjacent to the exit window in close contact with the incident surface 56a of the optical fiber screen 56. By a display device constituted in such a way, the luminance of a lap becomes high because the linear light source is used. Since the light emission part is linear and long, a wide range can be irradiated. Therefore, the irradiation light can be more uniformly guided to the display surface and the difference of the brightness can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more specifically, it guides light emitted from a linear light source to a liquid crystal display device, and transmits light transmitted through the liquid crystal display device to an optical fiber screen (a large number of optical fibers). One end of the optical fiber screen is arranged in close contact with each other, and the other end is arranged at a predetermined interval), and the light is guided to the incident surface of the optical fiber screen. The present invention relates to a display device that displays an enlarged still image or the like).

[0002]

2. Description of the Related Art Conventionally, as a display device using an optical fiber screen, a structure shown in FIG. 7 has been proposed. This display device includes a point light source 52 and a first lens system 6
1, the liquid crystal display 55, the second lens system 62, and the optical fiber screen 56, and the light from the point light source 52 is first converted into parallel rays by the first lens system 61. This is a well-known technique for slide projectors and the like because the lens design is easy because the light source is a point. The parallel light rays pass through the liquid crystal display 55, are enlarged by the second lens system 62, and then reach the incident surface 56 a of the optical fiber screen 56. The light rays from the liquid crystal display 55 to the incident surface 56a are enlarged parallel light rays, and the light fluxes are not mixed. Therefore, the image on the liquid crystal display 55 is faithfully displayed on the incident surface 56a.

[0003]

However, since the lamp used in the display device having the above structure is a point light source, it has the following problems. (1) The lamp life is about 1,000 hours, and it is necessary to replace the lamp at intervals of 1 to 2 months in order to display the flight schedule information of the airport which is continuously used for 24 hours. This has problems such as being forced to work at night considering not only the cost of replacement lamps but also the safety of airport users. (2) Further, it is difficult to increase the brightness of the point light source, so that the brightness of the emission surface 56b is restricted, and the display is difficult to see in a bright environment. (3) Also, since the lens system magnifies the light, the amount of light in the peripheral portion decreases, and uneven brightness occurs in the central portion and the peripheral portion within a single screen. In particular, when a plurality of optical fiber screens are arranged to achieve a large screen, the brightness at the boundary between the screens is reduced, and a high brightness part and a low brightness part occur in the large screen. ,, it will significantly reduce the image quality.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to improve the brightness of the entire display screen and improve its uniformity.

[0005]

A display device according to claim 1 is
The light emitted from the line light source is guided to the liquid crystal display, and the light transmitted through the liquid crystal display is guided to the incident surface, which is one end of the optical fiber screen. In the display device which displays the above display in an enlarged state, the liquid crystal display is directly opposed to the line light source,
In addition, they are arranged adjacent to each other and are in close contact with the incident surface of the optical fiber screen. The display device according to a second aspect of the present invention employs, as the line light source, a high brightness lamp and a reflector.

[0006]

According to the display device of the first aspect, since the linear light source is used, the brightness of the lamp is high. Further, since the light emitting portion is linear and long, it is possible to illuminate a wide range by combining with the reflector. Therefore, by guiding the light emitted from the linear light source to the liquid crystal display surface more evenly, it is possible to reduce the difference in luminance between the central portion and the peripheral portion. Further, since the liquid crystal display surface is in close contact with the incident surface of the optical fiber screen, the light transmitted through the liquid crystal display surface arrives at the incident surface without being scattered and is transmitted through the optical fiber. At this time, since there is no mixing of light between different optical fibers, the image on the liquid crystal display surface is accurately displayed on the exit surface without being out of focus.

According to the display device of the second aspect, since the linear light source comprising the high-intensity lamp and the reflector is employed, the same operation as that of the first aspect can be achieved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 shows a first display device according to the present invention.
It is a schematic diagram showing an example of. In this display device, a high-intensity metal halide lamp 2 is vertically arranged inside a light source casing 1, and a reflector 3 that efficiently guides light emitted from the lamp 2 downward is provided, and the lamp 2 is inclined at 45 degrees below the lamp 2. The IR cut mirror 4a is provided. Further, the UV cut filter 4b is provided on the exit window of the light source casing 1.
Is installed. At a position close to the exit window, the liquid crystal display 5 is installed in close contact with the incident surface 6a of the optical fiber screen 6.

In this embodiment, both the entrance surface 6a and the exit surface 6b are installed vertically. In addition, the UV cut filter 4b, which is the light emitting portion of the light source casing 1, and the liquid crystal display 5
A cooling fan 7 is installed to supply cooling air between and. If the surrounding environment is bad and a lot of dust is present, this part may have a closed structure to circulate clean cooling air with a cooler (not shown), or the liquid crystal display surface 5 may have a low ambient temperature. The cooling fan 7 can be omitted if the temperature rise is not a problem.

At the entrance surface 6a, as shown in FIG.
Optical fibers of m diameter are closely attached and laminated in a Δ array. On the other hand, on the exit surface (display section) 6b which is the other end of the optical fiber screen 6, as shown in FIG. 2B, the optical fibers 101 to 103 corresponding to the entrance surface 6a are arranged in the same manner at regular intervals of 2 mm pitch. The operation of the display device having the above configuration is as follows.

Light from the high-intensity metal halide lamp 2 is efficiently guided downward by the reflector 3 and the infrared path is removed by the IR cut mirror 4a, and then the optical path is changed by 90 degrees. Further, ultraviolet rays are removed by the UV cut filter 4b, and the liquid crystal display 5 near this is reached. The transmitted light of the liquid crystal display 5 transfers the image on the liquid crystal display 5 to the incident surface 6a, is further transmitted through the optical fiber, and is expanded to the emission surface (hereinafter referred to as an enlarged surface) 6b of the optical fiber screen 6. Is displayed. In addition, the surface of the liquid crystal display 6 is constantly cooled by the cooling fan 7, and deterioration of liquid crystal performance due to abnormally high temperature,
Prevents white spots (light is leaking even though black is displayed).

Further details will be described. Since the high-intensity lamp 2 is a linear light source, various problems (lifetime, brightness, spread of irradiation) derived from the above-mentioned point light source can be solved. Further, in the case of using the conventional point light source and lens system, the brightness difference between the central portion and the peripheral portion was about 3: 1, but in the present embodiment, this could be improved to 5: 2.

Further, since the infrared ray is removed by the IR cut mirror 4a and the ultraviolet ray is removed by the UV cut filter 4b, adverse factors that may increase the temperature of the liquid crystal display 5 and deteriorate its durability are eliminated. On the other hand, UV cut filter 4b
The light source that has passed through contains various scattered light. Therefore, if there is a gap between the liquid crystal display 5 and the incident surface 6a of the optical fiber screen 6, the light transmitted through the liquid crystal display 5 may not enter a predetermined fiber and may be mixed into an adjacent fiber. This leads to blurring of the image on the enlarged surface 6b. However, in the embodiment of the present invention, since the liquid crystal display 5 and the incident surface 6a of the optical fiber screen 6 are in close contact with each other, the liquid crystal display 5
The light that has passed through is incident on a predetermined fiber accurately. Therefore, a sharp image can be obtained on the enlarged surface 6b. The gap between the liquid crystal display 5 and the incident surface 6a of the optical fiber screen 6 needs to be equal to or less than twice the fiber diameter, and when high resolution such as computer information is required, It is desirable that the diameter is equal to or smaller than the fiber diameter.

[0014]

[Embodiment 2] A large improvement effect was recognized in the first embodiment, but unfortunately the brightness difference between the central portion and the peripheral portion is 5: 2. A dark part was formed in the sharp part. Therefore, the present inventors have made earnest studies and found that the cause of the brightness difference between the central portion and the peripheral portion is as follows.

(1) Since the high-intensity lamp 2 is a linear light source, when condensed by the reflector 3, as shown in FIG. 3, for example, the light emitted from the lower end of the linear light source is sufficiently condensed. (Refer to the arrow line A1 in FIG. 3), the light emitted from the upper end of the line light source is not sufficiently collected and is considerably diffused (see the arrow line A2 in FIG. 3). Become. In FIG. 3, broken lines P1 and P2 indicate the ends of the liquid crystal display 5.

(2) In the first embodiment, the distance from the lamp 2 to the liquid crystal display 5 is large and the size of the IR cut mirror 4a and the UV cut filter 4b is finite. The light is lost without being used effectively. Therefore, a further improved embodiment 2 is shown in FIG. In this embodiment, the reflector 3, the liquid crystal display 5, the optical fiber screen 6, the incident surface 6a, and the enlarged surface 6b.
Is equivalent to FIG. The function of the light source casing 1'is the same as that of the light source casing 1 in FIG. 1, but in the figure, it has a structure in which light is emitted from the left side surface. The lamp 2'is a high-intensity metal halide lamp as in the first embodiment, but is a horizontal installation type. IR cut mirror 4
a is not installed, but UV cut filter 4b instead
´ also has the function of cutting infrared rays.

According to this embodiment, since the liquid crystal display 5 is brought close to the lamp 2'and the reflector 3, the liquid crystal display 5 is arranged at the position indicated by B1 in FIG. Therefore, the light escaping to the outside indicated by the arrow A2 in FIG. 3 is also used. In other words, lamp 2
Most of the light radiated from ′ is guided to the liquid crystal display 5.
The brightness distribution on the liquid crystal display 5 when the liquid crystal display 5 is arranged at the position B1 in FIG. 3 is as shown by B1 in FIG. 5, and the entire range of the liquid crystal display 5 (from P1 In the range of P2), almost uniform brightness is obtained. Note that, in FIG. 5, the horizontal axis indicates the position of the liquid crystal display 5, but the distance from the reference point is on the extension line of the axis of the high-intensity lamp. The vertical axis represents the brightness of the reference point as 1
The relative luminance at each position on the liquid crystal display 5 when 00 is shown is shown.

When the liquid crystal display device 5 is installed at the positions shown by B2 and B3 in FIG. 3, the liquid crystal display device 5 is not irradiated with the light indicated by the arrow line A2 at all and is shown by B2 and B3 in FIG. As described above, the brightness (luminance) in the peripheral portion of the liquid crystal display 5 is significantly reduced. That is, when the IR cut mirror 4a is provided and the direction of light is changed by 90 degrees as in the first embodiment, the distance from the lamp 2 to the liquid crystal display 5 becomes long, which results in that in FIG. The positions are B2 and B3, and the difference in brightness between the central portion and the peripheral portion becomes significantly large.

However, also in the second embodiment, the following problems remain. (1) When a high-intensity lamp is placed horizontally, the temperature difference between the upper and lower sides of the arc tube section that emits high heat increases, which leads to deformation / damage of the lamp. Therefore, it is necessary to have a zone around the arc tube for self-cooling evenly. For example, the maximum diameter of a vertically installed lamp is 48 mmΦ, while that of a horizontally installed lamp is 116 mmΦ, which is 2.5 times as large. Also becomes. Therefore, the size of the light source casing including the reflector 3 becomes large.

(2) At the same time, the total luminous flux of the lamp is reduced by about 20% due to the strengthening of cooling, which directly decreases the brightness of the lamp (the higher the temperature of the arc tube section is, the brighter it is). (3) Further, since the light source casing 1'is installed after the optical fiber screen 6, the display device has a long depth.

FIG. 6 shows a third embodiment according to the present invention, which is a further improvement thereof.

[0022]

[Third Embodiment] FIG. 6 is a schematic view showing a third embodiment according to the present invention, which is further improved. In this embodiment, the high-intensity metal halide lamp 2 is vertically arranged inside the light source casing 1 ', and the reflector 3 for efficiently guiding the light emitted from the lamp 2 downward is provided to emit light from the lower surface of the light source casing 1'. It is a part. In this light emitting part,
A filter 4b 'that cuts both ultraviolet rays and infrared rays is installed. Then, the liquid crystal display 5 is arranged so as to face the filter 4b ′ and be close to the filter 4b ′, and the optical fiber screen 8 is arranged with the incident surface 8a being in close contact with the liquid crystal display 5. Further, the incident surface 8a of the optical fiber screen 8 is arranged horizontally. Furthermore,
Filter 4b 'of light source casing 1'and liquid crystal display 5
The cooling fan 7 can be omitted if the temperature rise of the above is not a problem.

The operation of the display device having the above configuration is as follows. In this embodiment. Since the IR cut mirror is omitted and the liquid crystal display 5 is brought close to the lamp 2 and the reflector 3, the liquid crystal display 5 is arranged at the position shown by B1 in FIG. The brightness distribution on 5 is shown in Fig. 5
As indicated by B1 in the figure, almost uniform brightness is obtained in the entire range of the liquid crystal display 5 (range from P1 to P2).

Further, since the lamp 2 is used vertically, it is possible to use a bright upper and lower installation type lamp, and it is possible to achieve a display device with high brightness and high uniformity. As a result, the problems of the second embodiment can be improved, and the brightness of the peripheral portion of the screen display surface is greatly improved. As a result, the difference in brightness between the central part and the peripheral part is improved to 4: 3, and when obtaining one image with multiple screens, there is almost no dark part in the part that straddles the screen like a conventional screen, A display device with high brightness and high uniformity can be obtained. Further, since the light source casing 1'is arranged in the upper space of the optical fiber screen 8,
Since a small-sized display device with a short depth can be formed and the screen and the light source system can be incorporated into one module to be unitized, the work becomes very easy when assembling a large number of screens.

[0025]

According to the first aspect of the present invention, it is possible to significantly suppress the decrease in the amount of light that is transmitted through the liquid crystal display and is guided to the optical fiber screen, and to reduce the difference in the amount of light between the central portion and the peripheral portion. It can be suppressed significantly, and as a result,
There is a unique effect that the brightness of the entire display screen can be increased without increasing the brightness of the light source, and the variation in the brightness on the display screen can be significantly suppressed.

The invention of claim 2 has the same effect as that of claim 1.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a display device of the present invention.

FIG. 2 is a schematic layout diagram of optical fibers on an entrance surface and an exit portion of an optical fiber screen.

FIG. 3 is a schematic diagram showing a state in which light from a lamp is condensed by a reflector.

FIG. 4 is a schematic view of a second embodiment of the display device of the present invention.

FIG. 5 is a diagram showing the brightness on the liquid crystal display when the positions of the liquid crystal display and the lamp are changed.

FIG. 6 is a schematic view of a third embodiment of the display device of the present invention.

FIG. 7 is a schematic diagram showing a configuration of a conventional display device.

[Explanation of symbols]

 2,2 'High-intensity metal halide lamp 3 Reflector 5 Liquid crystal display 6,8 Optical fiber screen 6a, 8a Incident surface 6b, 8b Exit surface

Claims (2)

[Claims] 1. The light emitted from the line light sources (2), (2 '), and (3) is guided to a liquid crystal display (5), and the light transmitted through the liquid crystal display (5) is converted into an optical fiber screen (6). In the display device for displaying the enlarged display on the liquid crystal display (5) on the exit surface (6b) which is the other end of the optical fiber screen (6) by guiding it to the entrance surface (6a) which is one end of the , Liquid crystal display (5) line light source (2) (2 ') (3)
It is located directly adjacent to and adjacent to
A display device, which is in close contact with the incident surface (6a) of the optical fiber screen (6). 2. The linear light source (2) (3) comprises a high intensity lamp (2) and a reflector (3).
The display device according to claim 1.