JP2001005407A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of suppressing the changes in the tints of the images on a screen by a difference in the observation direction of the screen and is improved in the luminance. SOLUTION: This projection type display device has plural monochromatic cathode ray tubes 11 and 12 to respectively emit light of respective monochromatic images of red, green and blue and magnifiably projects the monochromatic images of the light emitted by the respective monochromatic cathode ray tubes 11 and 12 onto the respective screen. The display device described above has the monochromatic cathode ray tubes 11R, 12R and 11B, 12B which project the monochromatic images to the screen 2 at a concentration angle θ of the directions reverse from each other with respect to the monochromatic cathode ray tubes 11G (12G) which are the same in light emitting colors and project the monochromatic images to the prescribed projection axis A direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device for enlarging and projecting images of a single color cathode ray tube of three colors of red, green and blue on a screen.

[0002]

2. Description of the Related Art For example, as shown in the principle diagram of a rear projection type display device 101 shown in FIG. 9, a monochromatic image of red (R), green (G) and blue (B) is formed by a projection type display device. Three cathode ray tubes 102R, 102G, and 102B that emit light are arranged in a line, and each cathode ray tube 102R, 102G, and 102B.
The image of B is magnified by the projection lens 103 and the screen 10
5 is a device for projecting the image on the screen. Rear projection display device 101
In the figure, the projection optical system and the observation position are on opposite sides of the screen, and the screen 105 is a transmissive screen, and diffuses the projected light. In a front projection display device in which the projection optical system and the observation position are on the same side of the screen, a reflective screen is used as the screen. Each cathode ray tube 1 projected on the screen 105
When the images of 02R, 102G, and 102B are superimposed, a color image is obtained when the screen 105 is viewed from the front.

[0003]

In the above-mentioned conventional projection display device, for example, as shown in FIG. 10, a cathode ray tube 102R, 102G, 102B arranged in a line, a cathode ray tube arranged at the center, 102G projects an image on the screen 105 in the direction of the projection axis A,
The cathode ray tube 102 arranged on one side of the cathode ray tube 102G
In R, the projection direction is inclined at a concentration angle θ with respect to the projection axis A. The cathode ray tube 102B disposed on the other side of the cathode ray tube 102G has a projection direction inclined with respect to the projection axis A at a concentration angle θ in a direction opposite to that of the cathode ray tube 102R.

Therefore, a so-called color shift occurs in which the color of the image projected on the screen 105 changes depending on the direction in which the screen 105 is observed. R,
As shown in FIG. 10, the relative luminance of each color of G and B is
The distribution is made according to the direction (angle) of observing the screen 105, and the direction in which the luminance of the screen 105 is maximized for each color is different. That is, among the relative luminance intensities of the R, G, and B colors, R and B are asymmetric with respect to the projection axis A. For example, when the screen 105 is observed from the direction along the projection axis A, a green (G)
When the screen 105 is viewed from the direction along the projection direction of the cathode ray tube 102R, red (R) looks strong. When the screen 105 is viewed from the direction along the projection direction of the cathode ray tube 102B, blue (B) is strong. appear. For this reason, when the images of the R, G, and B colors are superimposed, the color of the image changes depending on the direction in which the screen 105 is observed. On the other hand, with the recent increase in the size of the screen of the projection display device, it is required to improve the brightness of the screen. Therefore, it is necessary to increase the light amount of the cathode ray tube. However, when the size of the cathode ray tube is increased, there is a disadvantage that the above-mentioned concentration angle θ increases and the color shift increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantage, and it is possible to suppress a change in the color tone of an image on a screen due to a difference in the viewing direction of the screen, and to improve the brightness of a projection display. It is intended to provide a device.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a plurality of monochromatic cathode ray tubes for emitting monochromatic images of red, green and blue, respectively, and the monochromatic images emitted by the monochromatic cathode ray tubes are respectively displayed on a screen. A projection display device for enlarging and projecting,
At least two of the plurality of monochromatic cathode ray tubes project the monochromatic image on the screen at the same emission color and at a concentration angle opposite to each other with respect to a predetermined projection axis.

[0007] A monochromatic cathode ray tube of a first color for projecting the monochromatic image in the direction of the projection axis, and monochromatic cathode ray tubes of a second color and a third color for projecting the monochromatic image at mutually opposite convergence angles with respect to the projection axis. A plurality of sets of three cathode ray tubes each comprising a tube are provided, and the arrangement of the monochromatic cathode ray tubes of the second color and the third color of each set with respect to the monochromatic cathode ray tube of the first color is alternately different.

The first color monochromatic cathode ray tube emits a green monochromatic image.

A first-color monochromatic CRT for emitting a green monochromatic image, a second-color monochromatic CRT for emitting a red monochromatic image, and a third-color monochromatic CRT for emitting a blue monochromatic image; Has two sets of three monochromatic cathode ray tubes, one of which is arranged in order of red, green and blue, and the other of which is arranged in order of blue, green and red. ing.

[0010] A single first monochromatic cathode ray tube for projecting the monochromatic image in the projection axis direction and one side of the monochromatic cathode ray tube of the first color are arranged at a predetermined converging angle with respect to the projection axis. The monochromatic cathode ray tubes of the second color and the third color for projecting the monochromatic image and the other side of the monochromatic cathode ray tube of the first color are arranged on the other side of the monochromatic image at a concentration angle opposite to the predetermined concentration angle. And a monochromatic cathode ray tube for the second and third colors to be projected.

The amount of light from the first color monochromatic cathode ray tube is
Each of the second color and the third color is larger than the single color cathode ray tube.

The first color monochromatic cathode ray tube emits a green monochromatic image, the second monochromatic cathode ray tube emits a red monochromatic image, and the third color monochromatic cathode ray tube emits a blue monochromatic image. Emit a monochromatic image.

Further, the present invention comprises a plurality of monochromatic cathode ray tubes for emitting red, green and blue monochromatic images, respectively, and projects the monochromatic images emitted from the monochromatic cathode ray tubes on a screen in an enlarged manner. A display device, wherein at least two of the plurality of monochromatic cathode ray tubes emit the same color, and project the monochromatic image on the screen at a concentration angle opposite to each other with respect to a predetermined projection axis. A driving circuit that outputs a signal for driving each of the single-color cathode-ray tubes, and an adjustment that adjusts a signal output from the driving circuit to each of the single-color cathode-ray tubes to independently adjust the light emission amount of each of the single-color cathode-ray tubes. And a circuit.

According to the present invention, there is provided a monochromatic cathode ray for projecting a monochromatic image on a screen at a concentrated angle in which the emitted colors are the same and the projection axes are opposite to each other with respect to the projection axis. For this reason,
The distribution of the luminance of one of the light-emitting images on the screen and the distribution of the luminance of the other light-emitting image on the screen of these monochromatic cathode ray tubes are shifted in directions opposite to each other with respect to the projection axis. Therefore, by assembling these images, the asymmetry of the luminance distribution of the color with respect to the projection axis is suppressed. For example, if these single-color cathode rays have the same configuration and the same convergence angle, even if the viewing direction of the screen is changed, the luminance distribution of the image of the color projected on the screen becomes symmetric with respect to the projection axis, and the color shift No longer occurs.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a front view showing an example of a rear projection display device to which the present invention is applied, and FIG. 2 is a side view of FIG. FIG.
As shown in FIG. 2 and FIG. 2, the rear projection display device 1 includes a screen 2 provided on the front side of the device,
A reflecting mirror 5 provided at a distance behind and inclined in a predetermined direction, and six cathode ray tubes 11 fixed inside the apparatus.
R, 11G, 11B, 12R, 12G, and 12B. Each cathode ray tube 11 is provided with a projection lens 15.

The screen 2 projects an image emitted from each of the cathode ray tubes 11 and 12 from behind, and transmits and diffuses the image. The reflecting mirror reflects an image emitted from each of the cathode ray tubes 11 and 12 toward the screen 2.

The cathode ray tubes 11R and 12R emit a red (R) single-color image. The single-color image is enlarged through a projection lens 15, reflected by a reflecting mirror 5, and projected on a screen 2. The cathode ray tubes 11G and 12G emit a green (G) single-color image. The single-color image is magnified through the projection lens 15 and is reflected by the reflecting mirror 5 and projected on the screen 2.
The cathode ray tubes 11B and 12B emit a blue (B) monochromatic image, and this monochromatic image is enlarged through the projection lens 15,
The light is reflected by the reflecting mirror 5 and projected on the screen 2.

FIG. 3 is a view showing the arrangement of the cathode ray tubes 11 and 12 and is a view of each cathode ray tube viewed from the neck portion direction. As shown in FIG. 3, three cathode ray tubes 11
The set of R, 11G and 11B is the screen 2 in the device.
The three sets of three cathode ray tubes 12R, 12G, and 12B are arranged in a line in this order on the side.
11B, 11 behind the set of 1R, 11G, 11B
G and 11R are arranged in a line in the order. That is,
Behind the cathode ray tube 11R, a cathode ray tube 1 of a different color
2B are arranged, and a cathode ray tube 12G of the same color is arranged behind the cathode ray tube 11G.
A cathode ray tube 12R of a different color is arranged behind the cathode ray tube.

The cathode ray tubes 11G and 12G are disposed at the center and greatly affect the brightness and resolution of the image projected on the screen 2 and are arranged in a predetermined projection axis direction with respect to the screen 2 in a green monochromatic image. Is projected. Cathode ray tube 1 provided on one side of cathode ray tubes 11G and 12G
The 1R and cathode ray tube 12B project monochromatic red and blue images onto the screen 2 from a direction inclined at a concentration angle θ with respect to the projection axis. Cathode ray tubes 11G and 12
The cathode ray tube 11B and the cathode ray tube 12R provided on the other side of the G are blue from the direction inclined in the opposite direction to the cathode ray tube 11R and the cathode ray tube 12B at the concentration angle θ with respect to the projection axis with respect to the screen 2. And a monochromatic red image.

FIG. 4 is a block diagram showing an example of a driving circuit for driving each of the above-mentioned cathode ray tubes. As shown in FIG. 4, for example, a driving circuit for driving each of the above cathode ray tubes includes a tuner circuit 21, a video receiving circuit 22, a video output circuit 23, a synchronization / deflection circuit 24, and a color signal circuit 25.
And

The tuner circuit 21 is, for example, a circuit that selects a desired reception channel from a television signal of a predetermined frequency band obtained by the reception antenna 20, converts the channel into an intermediate frequency signal 21s, and outputs the intermediate frequency signal 21s. The video receiving circuit 22, for example, amplifies and detects the intermediate frequency signal 21s, and then outputs the luminance signal Y, the chrominance subcarrier signal 22sb, and the synchronization signal 22s.
and outputs the luminance signal Y to the video output circuit 23. The synchronization / deflection circuit 24 separates the synchronization signal, synchronizes the vertical / horizontal oscillators, creates a sawtooth current, and supplies the current to the deflection coils of the cathode ray tubes 11 and 12. The color signal circuit 25 performs color difference signals RY, G based on the color subcarrier signal 22sb separated by the video receiving circuit 22.
-Y and BY are created and output to the video output circuit 23.
The video output circuit 23 includes a luminance signal Y and color difference signals RY, G
-Y and BY output signals 23R, 23G and 23B to be supplied to the cathodes of the respective cathode ray tubes 11 and 12. The signal 23R is supplied to the cathode ray tubes 11R and 12R,
G is supplied to the cathode ray tubes 11G and 12G, and the signal 23B is supplied to the cathode ray tubes 11B and 12B.

Next, the display operation of the projection display device 1 having the above configuration will be described. From the television signal of a predetermined frequency band received by the antenna 20, a signal of a frequency of a desired channel to be received is selected by a tuner circuit 21, converted into an intermediate frequency signal 21s, and output to a video receiving circuit 22. The signal input to the video receiving circuit 22 is separated into a luminance signal Y, a chrominance subcarrier signal 22sb, and a synchronizing signal 22sa, and the video output circuit 23 outputs the luminance signal Y and the color difference signals RY, Signals 23R, 23G, and 23B are generated from GY and BY and output to the cathode ray tubes 11 and 12. The synchronization / deflection circuit 24
Supplies a high voltage to the deflection coils of the respective cathode ray tubes 11 and 12.

Thus, each of the cathode ray tubes 11R, 11R
G, 11B, 12R, 12G, 12B are driven, and red,
Each monochromatic image of green and blue is projected on the screen 2. The brightness of each monochrome image projected on the screen 2 is, for example,
The distribution is as shown in FIG. As shown in FIG. 5, the relative luminance distributions G1 and G2 of the images projected from the cathode ray tubes 11G and 12G are both symmetrical with respect to the projection axis A. Relative luminance distribution R1 and R2 of each image projected from cathode ray tubes 11R and 12R
Are asymmetric about the projection axis A for each,
The luminance distributions R1 and R2 are symmetric with respect to the projection axis A.
Similarly, the relative luminance distributions B1 and B2 of the images projected from the cathode ray tubes 11B and 12B are asymmetric with respect to the projection axis A, respectively, but the luminance distributions B1 and B2 are symmetric with respect to the projection axis A. is there.

Therefore, as shown in FIG. 5, the luminance distribution G0 due to the superposition of the images projected from the cathode ray tubes 11G and 12G, the luminance distribution R0 due to the superposition of the images projected from the cathode ray tubes 11R and 12R, The luminance distribution B0 resulting from the superposition of the images projected from the cathode ray tubes 11B and 12B is a distribution symmetric with respect to the projection axis A. For this reason, according to the projection display apparatus 1 according to the present embodiment, even when the screen 2 is viewed from a direction other than the direction of the projection axis A, a specific color does not appear strong depending on the direction. The change in the tint of the image on the screen 2, that is, the color shift does not completely occur. Further, according to the projection type display device 1 of the present embodiment, the place where the set of three cathode ray tubes 11R, 11G and 11B is used is usually replaced by the three cathode ray tubes 12
By adding the set of R, 12G, and 12B, the brightness of the screen 2 is doubled.

Second Embodiment FIG. 6 is a diagram showing an arrangement of a cathode ray tube of a projection display according to a second embodiment of the present invention. In the present embodiment, instead of the arrangement of the cathode ray tubes of the projection display device 1 in the above-described first embodiment, a green color is arranged between the cathode ray tubes 11R and 12B and the cathode ray tubes 11B and 12R in the direction of the projection axis A. The configuration is such that a single cathode ray tube 14G for projecting a monochromatic image is arranged. The cathode ray tube 13G is connected to another cathode ray tube 11
The cathode ray tube is larger in size than the cathode ray tubes R, 12B and the cathode ray tubes 11B, 12R. For this reason, the amount of light from the cathode ray tube 13G is larger than those of the other cathode ray tubes 11R and 12B and the cathode ray tubes 11B and 12R.

With this configuration, color shift does not occur in the image on the screen 2 and the number of cathode ray tubes to be used can be reduced by the same operation as the first embodiment. . Further, when the cathode ray tube 13G has the same size as the other cathode ray tubes, the amount of green light decreases, and a balance with other colors cannot be obtained.
By increasing the amount of light by increasing the size of the cathode ray tube 13G as compared with other cathode ray tubes, a balance with other colors can be obtained.

In the configuration of the cathode ray tube as shown in FIG. 6, for example, a driving circuit for driving the cathode ray tube having the configuration shown in FIG. 7 can be used. The drive circuit shown in FIG. 7 has a luminance adjustment circuit 2
6 are provided. The brightness adjustment circuit 26 is a video output circuit 2
3 by independently adjusting the magnitudes of the output signals 23R, 23G, and 23B from the cathode ray tube 13G and the other cathode ray tubes 11
This is a circuit for controlling the light amounts of R, 12B and 11B, 12R.

In the present embodiment, the tuner circuit 21 selects a signal of the frequency of the desired channel from the television signal of a predetermined frequency band received by the antenna 20,
The signal is converted into an intermediate frequency signal 21 s and output to the video receiving circuit 22. The signals input to the video receiving circuit 22 include a luminance signal Y, a chrominance subcarrier signal 22sb, and a synchronization signal 22.
sa, and the luminance signal Y and the color difference signals RY, GY, B from the chrominance signal circuit 25 in the video output circuit 23.
−Y and signals 23R, 23G, and 23B are generated and output to the luminance adjustment circuit 26. A high voltage is supplied from the synchronization / deflection circuit 24 to the deflection coils of the cathode ray tubes 11 and 12.

Each signal 23 output to the brightness adjustment circuit 26
R, 23G, and 23B are individually adjusted in size, and output to the cathode ray tube 13G and the other cathode ray tubes 11R, 12B and 11B, 12R. Thereby, the cathode ray tube 13G and the other cathode ray tubes 11R, 12B and 11B,
The light amount of the image on the screen 2 is adjusted, and the white balance of the image on the screen 2 can be made desired.

Third Embodiment FIG. 8 is a diagram showing an arrangement of a cathode ray tube of a projection display according to a third embodiment of the present invention. In this embodiment,
A set of three cathode ray tubes 11R, 11G and 11B arranged in this order for projecting monochromatic images of red, green and blue, respectively, and three cathode ray tubes 12B for projecting monochromatic images of blue, green and red, respectively. , 12G, 12R, red, green,
It has a set of three cathode ray tubes 13R, 13G and 13B arranged in this order for projecting blue monochromatic images, respectively.

According to the present embodiment, the cathode ray tubes 11G, 12G, and 13G for outputting each green single-color image are set at the center,
The arrangement of the cathode ray tubes on both sides is alternately changed, and the color shift can be suppressed by the same operation as the above-described embodiment. Furthermore, according to the present embodiment, since nine cathode ray tubes are provided, the brightness of the screen 2 can be further increased.

When the amount of light output from each of the cathode ray tubes 11, 12, and 13 is equal, the luminance distributions of the red and blue images on the screen 2 are completely symmetric with respect to the projection axis A. No. For this reason, the configuration may be such that the luminance adjustment circuit 26 as described in FIG. 7 is provided in the driving circuit of the cathode ray tube to balance the amount of light from each cathode ray tube. In this case, for example, the cathode ray tubes 11R, 1
By controlling the amount of light from 1G, 11B and 13R, 13G, 13B to be half of the amount of light from cathode ray tubes 12B, 12G, 12R, the occurrence of color shift can be completely suppressed.

In the embodiment described above, the case where the present invention is applied to a rear projection type display device has been described. However, the present invention is not limited to this. Can be similarly applied to a front projection display device on the same side as

[0034]

According to the present invention, it is possible to suppress a change in the color tone of the image on the screen due to the difference in the viewing direction of the screen and to improve the brightness of the screen.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a projection display device to which the present invention is applied.

FIG. 2 is a side view of the projection display device of FIG.

FIG. 3 is a diagram showing an arrangement of a cathode ray tube.

FIG. 4 is a configuration diagram showing a configuration example of a drive circuit for driving a cathode ray tube.

FIG. 5 is a diagram for explaining a relationship between an angle at which a screen is observed and luminance of each color.

FIG. 6 is a diagram showing an arrangement of a cathode ray tube of a projection display according to a second embodiment of the present invention.

7 is a configuration diagram showing a configuration example of a drive circuit for driving each cathode ray tube of FIG. 6;

FIG. 8 is a diagram showing an arrangement of a cathode ray tube of a projection display device according to a third embodiment of the present invention.

FIG. 9 is a diagram for explaining the principle of the rear projection display device.

FIG. 10 is a diagram for explaining a color shift that occurs in a conventional projection display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Projection display apparatus, 2 ... Screen, 5 ... Reflection mirror, 1
1R, 11G, 11B, 12R, 12G, 12B: cathode ray tube; 15: projection lens.

Claims (10)

[Claims] 1. A projection display device comprising a plurality of monochromatic cathode ray tubes each emitting a single color image of red, green, and blue, and enlarging and projecting the monochromatic image emitted by each of the monochromatic cathode ray tubes onto a screen. At least two of the plurality of monochromatic cathode ray tubes emit light of the same color and project the monochromatic image on the screen at a concentration angle opposite to each other with respect to a predetermined projection axis. apparatus. 2. A monochromatic cathode ray tube of a first color for projecting the monochromatic image in the direction of the projection axis, and a second color and a third color of the monochromatic image for projecting the monochromatic image at a concentration angle opposite to each other with respect to the projection axis. A plurality of sets of three cathode ray tubes each comprising a single color cathode ray tube, wherein the arrangement of the second color and the third color single color cathode ray tubes of each set with respect to the first color single color cathode ray tube is alternately different. 2. The projection display device according to 1. 3. The projection display device according to claim 2, wherein the first color monochromatic cathode ray tube emits a green monochromatic image. 4. A monochromatic cathode ray tube of a first color emitting a monochromatic image of green, a monochromatic cathode ray tube of a second color emitting a monochromatic image of red, and a monochromatic cathode ray tube of a third color emitting a monochromatic image of blue. And two sets of three single-color cathode-ray tubes comprising tubes, one of which is arranged in the order of red, green and blue,
4. The projection display according to claim 3, wherein the other monochromatic cathode ray tube is arranged in the order of blue, green, and red. 5. A single monochromatic cathode ray tube for projecting the monochromatic image in the direction of the projection axis, and arranged on one side of the monochromatic cathode ray tube of the first color, and a predetermined concentration on the projection axis. A monochromatic cathode ray tube of a second color and a third color for projecting the monochromatic image at a corner; and a monochromatic cathode ray tube arranged on the other side of the monochromatic cathode ray tube of the first color, wherein the monochromatic cathode ray tube has a converging angle opposite to the predetermined converging angle. 2. A monochromatic cathode ray tube of a second color and a third color for projecting an image.
3. The projection display device according to 1. 6. The light quantity from the first color monochromatic cathode ray tube is:
6. The projection display device according to claim 5, wherein each of the second color and the third color is larger than a single color cathode ray tube. 7. The monochromatic cathode ray tube of the first color emits a monochromatic image of green, the second monochromatic cathode ray tube emits a monochromatic image of red, and the monochromatic cathode ray tube of the third color comprises: 6. The projection display device according to claim 5, which emits a blue monochromatic image. 8. The projection display according to claim 1, wherein the single cathode ray tube projects an image from the back of the screen. 9. The projection display according to claim 1, wherein said single cathode ray tube projects an image from the front of said screen. 10. A projection display device having a plurality of monochromatic cathode ray tubes each emitting a monochromatic image of red, green, and blue, respectively, and enlarging and projecting the monochromatic image emitted by each of said monochromatic cathode ray tubes onto a screen. At least two of the plurality of monochromatic cathode ray tubes emit the same color, and project the monochromatic image on the screen at a concentration angle opposite to each other with respect to a predetermined projection axis. A drive circuit that outputs a signal for driving each of the single-color cathode-ray tubes; and an adjustment circuit that adjusts a signal output from the drive circuit to each of the single-color cathode-ray tubes to independently adjust the light emission amount of each of the single-color cathode-ray tubes. Projection display device.