JP2006011087A - Projector and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve bright color projection by increasing an amount of light of a specific color projected onto a screen, without increasing an amount of light emitted from a light source. <P>SOLUTION: The rotating speed of a color wheel 3 that is assigned to project a specific color onto the screen Sc is made low when the color filter for the component of light whose amount is the largest among the R, G, and B components of light projected onto the screen Sc is passed through a light illuminating section. When a color filter for the component of light whose amount is small among them is passed through the light illuminating section, the rotating speed of the color wheel 3 is made high. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a projector using DLP (Digital Light Processing) (registered trademark) technology and a method of controlling a color wheel used in the projector.

A projector using DLP (registered trademark) technology irradiates light onto a DMD (Digital Mirror Device) (registered trademark) in which a large number of reflectors are arranged on a semiconductor element, and enlarges and projects the reflected light with a lens. .

FIG. 1 shows a schematic layout of a projector using DLP (registered trademark) technology. A projector A shown in FIG. 1 includes a white lamp 1 that is a light source, a light tunnel 2 that equalizes the light intensity of light emitted from the light source, and a color wheel 3 that sequentially polarizes the light to wavelengths of RGB components. , DMD (registered trademark) 4 that reflects light, a light absorbing plate 5, and a projection lens 6.
Although a white lamp is used here as the light source, a light source that emits light having light of all the RGB wavelengths can be widely used besides the white lamp.

Although not limited thereto, the color wheel 3 is divided into six parts as shown in FIG. 3A, which will be described later. Each of the color wheels 3 has an R region including a color filter that polarizes light to an R wavelength,
A G region having a color filter polarized to the G wavelength and a B region having a color filter polarized to the B wavelength are formed. The DMD (registered trademark) 4 has a shape in which a reflector is arranged on the top of a semiconductor.

The operation of the projector A is as follows. The light is incident on the color wheel 3 after entering the light tunnel 2 that equalizes the light intensity from the white lamp 1. The color wheel 3 rotates at a high speed and a constant speed, and the light irradiated on the color wheel 3 passes through any of the R / G / B regions. At this time, the light transmitted through the R region is polarized into light of red wavelength, the light transmitted through the G region is polarized into light of green wavelength, and the light transmitted through the B region is polarized into light of blue wavelength. The DMD (registered trademark) 4 is continuously irradiated with light of each color wavelength.

The DMD (registered trademark) 4 reflects the irradiated light in a predetermined direction, and reflects necessary light among the red, green, and blue wavelengths passing through the color wheel 3 to the projection lens 6. Then, unnecessary things are reflected on the light absorbing plate 5. The light incident on the projection lens 6 is magnified and irradiated and displayed on the screen Sc. The color wheel 3 rotates at high speed, and the DMD (registered trademark) 4
Even if the light of each wavelength of RGB that is selectively reflected in the screen is sequentially irradiated on the screen, the human eye recognizes it as a composite color of RGB corresponding to the amount of reflection.

FIG. 3A shows an example of a color wheel used in the projector shown in FIG.
FIG. 3B shows a timing chart of the operating state of the color wheel shown in FIG.
Although not limited thereto, the color wheel 3 is divided into six equal parts in the circumferential direction, and regions facing the center are formed as an R region, a G region, and a B region, respectively. The color wheel 3 rotates in the direction indicated by the arrow in the figure.

The color wheel 3 is not limited thereto, but here, 7200 revolutions per minute (720
0 rpm), it takes about 8.4 ms for the color wheel 3 to make one rotation.
At this time, the time for which the light emitted from the white lamp 1 is applied to one region is about 1.4 ms. The color wheel 3 is rotating, and the first half of 0.2 ms and the second half of 0.2 ms are not used because the adjacent areas are also irradiated with light.

FIG. 3B shows a screen S in which colors mixed at R (red): G (green): B (blue) = 5: 1: 1.
It is a timing chart when displaying on c. The rotation speed of the color wheel 3 at the top, the DMD (registered trademark) reflecting at the projection lens or the light absorbing plate at the middle, the reflection time of the light projected on the screen at the bottom, The bottom row shows the time required for each region of RGB to pass through the light irradiation part. The color wheel 3 has the same order (R region,
Light is irradiated to the G region and the B region. Here, for convenience, the half circumference of the color wheel 3 is shown as a timing chart.

It is 1.4 ms that the R region is irradiated with light, and 0.2 ms before and after that may be mixed with light of wavelengths of the color wheel 3 before and after the R region (that is, B before and G after). is there.
Therefore, among the lights transmitted through the R region by driving the DMD (registered trademark) 4, the front and rear are 0.2.
ms is reflected so as to irradiate the light absorbing plate 5. Then, by reflecting the remaining 1.0 ms so as to irradiate the projection lens 6, the projection lens 6 is irradiated with light having a red wavelength (FIG. 3 (
B)).

Next, since the color component of green (G) is 1/5 of the color component of red (R), DMD (registered trademark) 4
Reflects to irradiate the projection lens 6 for 0.2 ms while light passes through the G region, and reflects to irradiate the light absorbing plate 5 otherwise. In the B region, similarly to the G region, the light is reflected by the projection lens 6 for 0.2 ms, and the other light is reflected so as to irradiate the light absorbing plate 5 (see FIG. 3B).

In this way, R wavelength light is 1.0 ms, G wavelength light, and B wavelength light is 0.2 ms each.
The projection lens 6 is irradiated and the screen Sc is irradiated. The time taken during this period was 4.2
Since it is ms, the screen Sc has R (red): G (green): B (blue) = 5: 1.
It looks like it was irradiated with light mixed at 1: 1. A full-color image can be projected on the screen Sc by changing the RGB component ratio by the same method as described above.
JP 2003-295318 A JP 2003-307705 A

However, above. In the case of light mixed at R (red): G (green): B (blue) = 5: 1: 1, the irradiation time of the light of R wavelength is 1.0 ms, the light of G wavelength, B wavelength of light The irradiation times are each 0.2 ms, for a total of 1.4 ms. The color wheel 3 has a half circumference of 4.2 ms.
Therefore, in this case, 2/3 of the color wheel 3 makes a half turn reflects light to the light absorbing plate 5, and the amount of image projected on the screen Sc is reduced accordingly.

In the above example, the case of R (red): G (green): B (blue) = 5: 1: 1 is described as an example, but the same applies to other cases. That is, the irradiation time of light of each wavelength when the color projected on the screen Sc is decomposed into RGB components is 1.0 ms at the maximum. Based on this irradiation time, the irradiation time of the light of the other color wavelength is determined, so that the time for reflecting the light to the light absorbing plate 5 becomes longer. As a result, the amount of light projected onto the screen Sc is small, and the screen S
It is difficult to project a bright image on c, that is, the light utilization efficiency of the white lamp 1 is poor.

Accordingly, an object of the present invention is to increase the amount of light of a predetermined color projected onto the screen without increasing the amount of light emitted from the light source, and to project brightly and vividly.

In order to achieve the above object, the invention according to claim 1 includes a white lamp that emits white light, a light tunnel that equalizes the light intensity of the white light emitted from the white lamp, and six equal centers. A disc-shaped color wheel that is divided into regions having angles and in which R / G / B color filters are arranged in a predetermined order in each region, and a reflector that reflects light transmitted through the color wheel A light absorbing plate that absorbs light, and a projection lens that projects light onto a screen, and the color wheel is rotated and light emitted from the light tunnel Is transmitted through one of the color filters, and the light is sequentially polarized into light of each wavelength of RGB, and the DMD (registered trademark) drives the reflector and enters the light of RGB color. of In other words, the light of the necessary color is reflected toward the projection lens for a necessary time, and the unnecessary light is reflected toward the light absorbing plate. The time required for one rotation of the color wheel is as follows: The rotation speed of the color wheel when the predetermined color is projected onto the screen is the same as that of the RGB component of the color projected onto the screen. Provided is a projector characterized in that it is slow when passing through an irradiating unit and rotates fast when a color filter that polarizes light with a small amount of light passes through it.

According to this configuration, when a predetermined color is projected onto a screen, light is irradiated for a long time to a region having a color filter that polarizes light of a component that is included in a large amount of RGB components of the color, and in a small portion a short time. Since the color wheel is rotated so as to emit light, the total light irradiation time can be extended.

As a result, even when a predetermined color is projected onto the screen using a lamp having the same light amount, the light irradiation time to the screen is long and the light amount is large, so that a bright image is projected. Is possible. In addition, since the time required for one rotation of the color wheel is the same as that during constant speed rotation, it is possible to suppress the occurrence of flicker (flicker) that occurs when the rotation speed decreases.

In order to achieve the above object, the invention according to claim 2 is directed to a light source capable of outputting light including RGB color components equally or substantially uniformly, and a light that equalizes the light intensity of the light emitted from the light source. A disc-shaped color wheel which is divided into a tunnel and regions having equal central angles, and the same number of R / G / B color filters are arranged in a predetermined order in each region; DMD (registered trademark) including a reflecting plate that reflects the light, a light absorbing plate that absorbs light, and a projection lens that projects light onto a screen, and the color wheel is rotated, The light emitted from the light tunnel passes through one of the color filters, and is sequentially polarized into light of each wavelength of RGB. The DMD (registered trademark) is incident upon driving the reflector. Of the RGB light, the light of a necessary color is reflected toward the necessary time projection lens, and the unnecessary light is reflected toward the light absorbing plate. The time required for one rotation of the color wheel Is the same as when rotating at a constant speed, and the rotation speed of the color wheel when a predetermined color is projected onto the screen is the RG of the color projected onto the screen.
Among the B components, a color filter that polarizes light with a large amount of component is slow when passing through the light irradiating unit, and rotates fast when a color filter that polarizes light with a small amount of component passes. Provide a projector.

According to this configuration, a light source that includes light of each wavelength of R / G / B equally or substantially uniformly is employed, so that any color can be projected vividly on the screen. is there.

In order to achieve the above object, according to the third aspect of the present invention, R / G / B is obtained by transmitting light including RGB color components equally or substantially equally through a light tunnel that equalizes light intensity. Irradiate a disk-shaped color wheel in which the same number of color filters are arranged in the prescribed order,
The light of the respective colors RGB is sequentially polarized, and the light of the necessary color out of the light transmitted through the color wheel by DMD (registered trademark) is reflected to the necessary time projection lens, and the other light is reflected to the light absorbing plate. In the projector, when the color wheel is rotated so that the time of one rotation of the color wheel is the same as that at the constant speed rotation, and when a predetermined color is projected onto the screen, the rotation speed of the color wheel is set to the RGB of the color. Among the components, a projector that rotates slowly when a color filter that polarizes light with a large amount of light passes through the light irradiating unit, and rotates fast when a color filter that polarizes light with a small amount of light passes through it. A control method is provided.

According to this configuration, it is possible to project bright and colorful colors without increasing the amount of light emitted from the light source by optimally controlling the rotational speed of the color wheel without changing the basic configuration of the projector. Is possible.

Thus, by changing the speed control of the color wheel of the existing projector, the light amount of the image projected on the screen can be increased, and accordingly, the cost can be reduced and the waste can be reduced.

In order to achieve the above-mentioned object, the invention according to claim 4 is a method in which light containing R, G, and B color components uniformly or substantially uniformly is transmitted through a color tunnel that equalizes light intensity, and then R / G / B Irradiate a disk-shaped color wheel in which the same number of color filters are arranged in the prescribed order,
The light of the respective colors RGB is sequentially polarized, and the light of the necessary color out of the light transmitted through the color wheel by DMD (registered trademark) is reflected to the necessary time projection lens, and the other light is reflected to the light absorbing plate. In the projector, the color wheel is rotated so that the time of one rotation of the color wheel is the same as that at the constant speed rotation, and when the predetermined color is projected onto the screen, the rotation speed of the color wheel is set to the RGB component of the color. Of the color wheel, the color filter that polarizes light with a large amount of light is slow when passing through the light irradiating part, and the color wheel that rotates lightly when the color filter that polarizes light with a small amount of light passes through. Provide a control method.

According to this configuration, by controlling the rotation speed of the color wheel optimally, it is possible to project bright and colorful colors without increasing the amount of light emitted from the light source.

Thus, by changing the speed control of the existing color wheel, it is possible to increase the amount of light of the image projected on the screen, thereby reducing costs and reducing waste.

According to the present invention, it is possible to provide a projector and a color wheel control method that can increase the amount of light projected on the screen without increasing the amount of light emitted from the light source, and can project brightly and vividly. .

In addition, according to the present invention, the amount of light projected on the screen can be adjusted by controlling the rotation speed of the color wheel, so that it can be applied to existing projectors, and is simple and inexpensive. A wheel control method can be provided.

The best mode for carrying out the present invention will be described with reference to the drawings. The projector according to the present invention has the same configuration as the projector A shown in FIG. That is, RGB
The light passes through the white lamp 1 that outputs white light including the wavelength of each color, the light tunnel 2 that equalizes the light intensity of the light emitted from the white lamp 1, and the light emitted from the light tunnel 2. A color wheel 3 having a color filter that sometimes polarizes to one of the RGB wavelengths, a DMD (registered trademark) 4 having a reflector that reflects light transmitted through the color wheel 3, and a DMD (registered trademark) A light absorbing plate 5 for irradiating unnecessary light out of the light reflected at 4 and absorbing the light; and a projection lens 6 for enlarging the light reflected by the DMD (registered trademark) 4 and projecting it on the screen Sc. have.

The light emitted from the white lamp 1 passes through the light tunnel 2 to equalize the light intensity, and is then applied to the color wheel 3. The color wheel 3 is rotating and polarized to light of RGB wavelength according to the color filter arranged at the position where the light is irradiated when one of the RGB regions is irradiated and the light is transmitted. The The light transmitted through the color wheel 3 is D
Light that is reflected by the MD (registered trademark) 4 and is necessary for projecting an image is applied to the projection lens 6, and unnecessary light is applied to the light absorption plate 5. The light applied to the projection lens 6 is magnified and the screen S
By irradiating c, an image is projected on the screen Sc.

FIG. 2A is a schematic diagram of a color wheel provided in the projector according to the present invention, and FIG. 2B is a timing chart of the operation of the color wheel shown in FIG. As shown in FIG. 2A, the color wheel 3 is not limited thereto, but is divided into six equal parts in the circumferential direction here. The six-divided region includes an R region having a color filter that polarizes incident light into light of R (red) wavelength, a G region that polarizes light of G (green) wavelength, and B (blue). Two each of the B regions that are polarized to the light of the wavelength are arranged across the center.

The timing chart shown in FIG. 2B is the same color as in the conventional example (R: G: B = 5:
(1: 1) is displayed on the screen Sc. The top row shows the rotation speed of the color wheel, the middle row shows whether the DMD (registered trademark) is reflected by the projection lens or the light absorbing plate, the bottom row shows the reflection time of the light projected on the screen, and the bottom row Indicates the time required for each region of RGB to pass through the light irradiation part.

At this time, since a large amount of R (red) component is contained, the rotation speed of the color wheel 3 is decreased when the R region passes the light irradiation position in order to irradiate the R region with light for a long time. And
Increase the irradiation time of light to the R region. Further, since the G (green) component and the B (blue) component are 1/5 of the R (red) component, when the G region and the B region pass through the light irradiation position, the rotation speed of the color wheel 3 is increased, The irradiation time of light to the G region and the B region is shortened.

Specifically, it is as follows. When the color wheel 3 rotates about 7200 per minute, the time required for the color wheel 3 to rotate once is 8.4 ms. Since the R / G / B areas are arranged in the same order in the color wheel 3 every half circle, the half circle is considered here for convenience.

As shown in FIG. 2B, when the R region passes through the light irradiation position, the rotation speed of the color wheel 3 is lowered. Further, when the R region ends and the G region and B region pass through the light irradiation position, the rotation speed of the color wheel 3 is increased. At this time, the time for the R region to pass through the light irradiation position is 2.8 ms, and the time for the G region and B region to pass through the light irradiation position is both 0.
. 7 ms. As a result, the time taken for the color wheel 3 to make a half turn is 4.2 ms.
Since it takes 8.4 ms to make one round, the average rotation speed is the same as that rotating at 7200 rpm.

DMD (registered trademark) 4 is irradiated with the light transmitted through the R region. Here, the DMD (registered trademark) 4 is driven and reflected on the projection lens 6 as long as possible (here, 2.0 ms), and the rest is reflected on the light absorbing plate 5. At this time, 0 before and after the R region passes through the light irradiation position.
. 4 ms is easily affected by the color filters in other areas, and is reflected by the light absorbing plate 5.

Further, in the G region and the B region, the R region is 2.0 ms, so that it is reflected to the projection lens for 1/5 of the time, that is, 0.4 ms, and the rest is reflected to the light absorbing plate 5. At this time, R
For the same reason as that of the region, the light absorbing plate 5 is reflected for 0.15 ms before and after.

In this way, by changing the rotation speed of the color wheel 3 in accordance with the RGB components of the color projected on the screen Sc, the time required for the DMD (registered trademark) 4 to reflect to the projection lens 6 in the R region is 2. 0 ms, reflection time in the G region is 0.4 ms, reflection time in the B region is 0.4
ms, and the irradiation time of light to the projection lens 6 per half circumference of the color wheel 3 is 2.8 m.
s. This is because the time required for the half circumference of the color wheel 3 is 4.2 ms, so that 2/3 of the light transmitted through the color wheel 3 is irradiated onto the projection lens 6.

This is about twice the time when the color wheel 3 is rotating at a constant speed, and the amount of light is 2
Since it is doubled, it is possible to project a bright color on the screen Sc. Further, the time required for the color wheel 3 to make a round is the same as that when rotating at a constant speed, and flickering due to low-speed rotation does not occur.

Here, the rotation speed of the color wheel 3 cannot be changed instantaneously. Even if the transmitted light is being decelerated or accelerated, there is no change in the light that has passed through each color filter, and it may be reflected by the DMD (registered trademark) 4 to the projection lens 6. The reflection time of 2.0 ms in the R region and the reflection time of 0.4 ms in the G and B regions do not need to be constant.

In the example described above, the display example of the color mixed by R: G: B = 5: 1: 1 is shown. However, if the color can be expressed by RGB, the color wheel control method of the present invention. It is possible to project colors of any mixing ratio onto the screen.

It is a schematic layout diagram of a DLP (registered trademark) projector. 1A is a diagram showing a color filter used in the projector shown in FIG. 1, and FIG. 2B is a timing chart showing the operation of the color filter controlled by the color filter control method according to the present invention. . 1A is a diagram showing a color filter used in the projector shown in FIG. 1, and FIG. 2B is a timing chart showing an operation of the color filter controlled by a conventional color filter control method.

Explanation of symbols

A Projector 1 White lamp 2 Light tunnel 3 Color wheel 4 DMD (registered trademark)
5 Light absorbing plate 6 Projection lens

Claims (4)

A white lamp that emits white light;
A light tunnel that equalizes the light intensity of the white light emitted from the white lamp;
It is divided into six regions having equal central angles, and R / G /
A disc-shaped color wheel in which the color filters of B are arranged;
DMD (registered trademark) provided with a reflector that reflects the light transmitted through the color wheel;
A light absorbing plate that absorbs light;
A projection lens that projects light onto the screen,
The color wheel is rotating, and the light emitted from the light tunnel passes through one of the color filters, so that the light is sequentially polarized into light of each wavelength of RGB,
The DMD (registered trademark) drives the reflecting plate to reflect the required color light of the RGB color light incident thereon toward the necessary time projection lens, and directs unnecessary light to the light absorbing plate. Is reflected,
The time required for one rotation of the color wheel is the same as that during constant speed rotation,
The rotation speed of the color wheel when a predetermined color is projected onto the screen is such that a color filter that polarizes light of components included in the RGB components of the color projected onto the screen passes through the light irradiation unit. A projector characterized in that it rotates slowly when rotating, and rotates fast when a color filter that polarizes light with a small amount of light passes. A light source capable of outputting light including each color component of RGB equally or substantially uniformly;
A light tunnel that equalizes the light intensity of the light emitted from the light source;
A disc-shaped color wheel that is divided into regions having equal central angles, and each region has the same number of R / G / B color filters arranged in a predetermined order;
DMD (registered trademark) provided with a reflector that reflects the light transmitted through the color wheel;
A light absorbing plate that absorbs light;
A projection lens that projects light onto the screen,
The color wheel is rotating, and light emitted from the light tunnel is sequentially polarized into light of each wavelength of RGB by passing through one of the color filters.
The DMD (registered trademark) drives the reflecting plate to reflect the required color light of the RGB color light incident thereon toward the necessary time projection lens, and directs unnecessary light to the light absorbing plate. Is reflected,
The time required for one rotation of the color wheel is the same as that during constant speed rotation,
The rotation speed of the color wheel when a predetermined color is projected onto the screen is such that a color filter that polarizes light of components included in the RGB components of the color projected onto the screen passes through the light irradiation unit. A projector characterized in that it rotates slowly when rotating, and rotates fast when a color filter that polarizes light with a small amount of light passes. A disc-like shape in which R, G, and B color filters are arranged in a predetermined order in equal numbers after light that contains RGB color components uniformly or substantially uniformly is transmitted through a light tunnel that equalizes the light intensity. The color wheel is irradiated with light, sequentially polarized into RGB light, and the light of the required color out of the light transmitted through the color wheel by DMD (registered trademark) is reflected to the required time projection lens and other light is reflected. Is a projector that reflects on a light absorbing plate,
When the color wheel is rotated so that the time of one rotation of the color wheel is the same as that at the time of constant speed rotation, and when a predetermined color is projected onto the screen, the rotation speed of the color wheel is determined from among the RGB components of the color. A projector control method characterized by slow rotation when a color filter that polarizes light with a large amount of light passes through the light irradiating portion and fast rotation when a color filter that polarizes light with a small amount of light passes through . Discs in which R, G, and B color filters are arranged in a predetermined order in equal numbers after light that contains RGB color components uniformly or substantially uniformly is transmitted through a color tunnel that equalizes the light intensity. The color wheel is irradiated with light, sequentially polarized into RGB light, and the light of the required color out of the light transmitted through the color wheel by DMD (registered trademark) is reflected to the required time projection lens and other light is reflected. Is a projector that reflects on a light absorbing plate,
The color wheel is rotated so that the time of one rotation of the color wheel is the same as that at the time of constant speed rotation, and when the predetermined color is projected onto the screen, the rotation speed of the color wheel is increased among the RGB components of the color. A projector control method characterized in that a color filter that polarizes light of contained components is rotated slowly when passing through a light irradiating unit, and is rotated rapidly when a color filter that polarizes light of less components passes.

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