JP5152008B2 - Projector device - Google Patents

Description

  The present invention relates to a projector device that splits light from a discharge lamp into a plurality of colored lights by passing through a color wheel having a plurality of segments.

Recently, projector devices such as a liquid crystal display (LCD) device and a DLP using a DMD have become popular, and the field of use has expanded to home theater use in addition to business use. Along with such changes in usage, there has been a demand for high-color reproducibility, which emphasizes so-called color, from the mere importance of brightness as in the prior art.
In order to cope with such a flow, various improvements have been made on the color wheel of the projector apparatus.

  The color wheel is a technique that has been widely used as a coloring means for an image projected on a projector apparatus, and is particularly useful for a DLP of a single-panel display panel or an LCD type projector apparatus.

  This color wheel will be described with reference to FIG. The color wheel 10 is divided into a plurality of, for example, four substantially fan-shaped segments 17a to 17d in the circumferential direction, and wavelength selective color filter layers 15a to 15d that transmit light of a desired color are formed. It will be. Each of the color filter layers 15a to 15d transmits white light (W light), red light (R light), green light (G light), and blue light (B light) which are the three primary colors of light. It is supposed to be transparent.

If necessary, the color wheel may be, for example, complementary cyan light (C light), magenta light (M light), yellow light (Y light) in addition to W light, R light, G light and B light. For example, the color filter layer may be provided. The occupation angle range of each segment in the color wheel 10 is set according to the intensity and brightness required for each color light.
By rotating such a color wheel 10 at high speed and irradiating light to the fixed irradiation spot region S, light can be dispersed in a time division manner.

A projector apparatus using such a color wheel 10 as a coloring means will be described with reference to FIG.
The projector device 30 includes a light source device 35 and a color wheel that splits the visible light L1 emitted from the light source device 35 into one of W light, R light, G light, and B light and splits it into colored light L2. 10. In the projector device 30, the colored light L <b> 2 that has passed through the color wheel 10 is emitted from the rod lens 31 as equal luminance light L <b> 3 with uniform illuminance at the cross section. Then, it becomes condensed light L4 through the integrator lens 32, and the image light L5 formed by modulating the condensed light L4 in the display device 33 such as DMD is enlarged and projected on the screen (not shown) by the projection lens 34. Is done.

In such a projector apparatus, for example, in Patent Document 1, the input power of the lamp is controlled according to the color type of the color filter layer that has come to the irradiation spot area of the light source lamp in order to adjust the color balance. Is disclosed.
By controlling the input power of such a lamp, the projector device can have high color reproducibility suitable for, for example, a home theater. Specifically, the projection image obtained by normal time division is generally perceived to be less reddish by the observer, so it is effective to perform control to increase the input power of the lamp related to the R light.

JP 2007-121971 A

However, it has been found that the following problems occur in the projector device using such a color wheel.
That is, light in a wavelength range other than light in a specific wavelength range that passes through each color filter layer in the color wheel is returned to the discharge lamp as reflected light. By irradiating the electrode of the discharge lamp with the return light, the temperature of the electrode rises more than expected, resulting in problems such as a decrease in illuminance and a short life of the discharge lamp.
The above-mentioned problem appears particularly remarkably when the B light is contained in a large amount in the return light, specifically, when control is performed to increase the input power of the lamp related to the R light.

  The present invention has been made based on the circumstances as described above, and the object thereof is to reduce the amount of return light from the color wheel, and as a result, excessive temperature rise in the electrodes of the discharge lamp is suppressed. An object of the present invention is to provide a projector device that can suppress a decrease in the illuminance of the discharge lamp and can maintain a high illuminance of the discharge lamp for a long period of time, so that high color reproducibility can be obtained in a projected image.

The projector device according to claim 1 includes a discharge lamp, and a color wheel including a plurality of segments that rotate to disperse the light from the discharge lamp into colored light according to transmission characteristics. In the projector device that modulates the light output of each colored light by changing the input power, the color wheel partitions the translucent substrate and the segments formed on the light emitting side surface of the translucent substrate. A plurality of color filter layers, wherein one of the color filter layers is a specific color filter layer that transmits light in a wavelength region of 600 to 780 nm, and the translucent substrate facing the specific color filter layer is , A specific transparent substrate that absorbs light in the wavelength range of 380 to 500 nm, and among the plurality of segments, the specific color filter layer and the A segment is defined as a specific segment from a combination with a constant transmission substrate, and the specific transmission substrate constituting the specific segment has a light absorption rate of 80% or less per 1 mm in thickness at 380 nm light, Thickness T satisfies the following (Formula 1).
(Formula 1)
T ≧ {−0.68 (A / B) ² +3.10 (A / B) −2.45} × C / 120 °
T is the thickness of the specific transparent substrate (mm)
A is the input power (W) of the discharge lamp in a specific segment
B is the average input power (W) of the discharge lamp across all segments
C is the occupancy angle of a specific segment (°)

  A projector device according to a second aspect is the projector device according to the first aspect, and is characterized in that, in particular, a thickness T of the specific transparent substrate is 1 mm or less.

According to the projector device of claim 1, the color wheel is formed with the specific color filter layer that transmits light in the wavelength range of 600 to 780 nm, and the translucent substrate facing the specific color filter layer is 380. It is a specific transmission substrate that absorbs light in a wavelength region of ˜500 nm, and a segment is defined as a specific segment from a combination of a specific color filter layer and a specific transmission substrate among a plurality of segments of the color wheel. The specific transparent substrate constituting the specific segment has a light absorption rate of 80% or less per 1 mm thickness in light of 380 nm, and the thickness T satisfies the following (formula 1). The amount of return light to the discharge lamp can be reduced, excessive temperature rise at the electrode of the discharge lamp is suppressed, a decrease in the illuminance of the discharge lamp is suppressed, and the illuminance of the discharge lamp is kept high over a long period of time. Therefore, the projector device can obtain high color reproducibility in the projected image.
(Formula 1)
T ≧ {−0.68 (A / B) ² +3.10 (A / B) −2.45} × C / 120 °
T is the thickness of the specific transparent substrate (mm)
A is the input power (W) of the discharge lamp in a specific segment
B is the average input power (W) of the discharge lamp across all segments
C is the occupancy angle of a specific segment (°)

  Furthermore, according to the projector device of the second aspect, when the thickness T of the specific transmissive substrate is 1 mm or less, it is possible to prevent the color wheel from becoming thick, and the position of the color wheel can be changed from the conventional position. It can be the same as the arrangement position, and furthermore, the color wheel that rotates at high speed is not decentered, and the projector device can maintain the optimum rotation state.

It is a front view for explanation which shows typically an example of composition of a color wheel in a projector device of the present invention. It is sectional drawing of the XX line part in FIG. It is a front view for explanation which shows a translucent board typically. It is explanatory drawing of the projector apparatus of this invention. It is explanatory drawing about the relationship of the input electric power of the discharge lamp in each segment of the color wheel of the projector apparatus of this invention. It is the experimental data which investigated the change of the illumination intensity maintenance factor in the relationship between the thickness of the specific permeable board | substrate of a specific segment, and the input electric power of a discharge lamp. Based on the experimental results shown in FIG. 6, the value of A (discharge lamp input power in a specific segment) / B (discharge lamp average input power over all segments) and the specification for suppressing the decrease in illuminance maintenance rate It is a graph of the relationship with the thickness T (mm) of a transparent substrate.

FIG. 1 is an explanatory front view schematically showing an example of the configuration of a color wheel in the projector apparatus of the present invention, FIG. 2 is a cross-sectional view taken along line XX in FIG. 1, and FIG. It is a front view for explanation which shows a translucent board typically.
The color wheel 10 includes segments 17a to 17d in which color filter layers 15a to 15d that respectively transmit light in different wavelength ranges are formed on the surface of the light emitting side of a disc-shaped translucent substrate 12 made of glass. Is.
The translucent substrate 12 includes four substantially fan-shaped glass plates 12 a to 12 d, and the center side of the fan of each glass plate 12 a to 12 d is connected to and supported by a shaft 19 positioned at the center of the translucent substrate 12. ing.
In this embodiment, the translucent substrate 12 is a combination of four glass plates 12a to 12d so as to correspond to the four segments 17a to 17d, but the color filter layers 15a, 15d and 15c are combined. The glass plate may correspond to straddle, and in this case, the translucent substrate 12 is composed of the glass plate 12b and another glass plate.
The color filter layers 15a to 15d are formed of, for example, a dielectric multilayer film.

In the color wheel 10 of this example, four color filter layers that partition each segment are formed on the surface of the light transmitting side of the translucent substrate 12, and white light (W light) and light respectively. Color filter layers 15a to 15d that transmit red light (R light), green light (G light), and blue light (B light) that are the three primary colors are formed.
Such a color wheel 10 is rotated at a high speed and irradiates light to the fixed irradiation spot region S, thereby converting the light from the discharge lamp into colored light according to the transmission characteristics of the color filter layers 15a to 15d. Spectroscopy in a time division manner.

In the color wheel 10, the color filter layer 15b transmits red light (R light) in the wavelength range of 600 to 780 nm, and this color filter layer 15b is referred to as a specific color filter layer 15b.
The translucent substrate 12b facing the specific color filter layer 15b absorbs blue light (B light) in a wavelength range of 380 to 500 nm, and the translucent substrate 12b is referred to as a specific translucent substrate 12b. .
A segment is defined as a specific segment 17b from the combination of the specific color filter layer 15b and the specific transparent substrate 12b.

As shown in FIGS. 1 and 3, the translucent substrate 12 is formed by combining four substantially fan-shaped glass substrates 12 a to 12 d to form one disc-shaped translucent substrate 12. The angle that the specific transparent substrate 12b occupies with respect to the entire substrate 12 is the fan opening angle, which is 120 ° in this embodiment.
The occupying angle (°) of the specific segment 17b is defined by the opening angle of the fan of the specific transmissive substrate 12b. In this embodiment, the occupying angle of the specific segment 17b is 120 °.
Similarly, the occupation angle of the segment 17a that transmits white light (W light) is 60 °, the occupation angle of the segment 17c that transmits green light (G light) is 60 °, and blue light (B light) is transmitted. The occupied angle of the transmitting segment 17d is 120 °.

A projector apparatus using such a color wheel 10 as a coloring means will be described with reference to FIG.
The projector device 30 reflects the visible light L1 emitted from the discharge lamp 35a of the light source device 35 by the reflecting mirror 35b, and irradiates the color wheel 10 with the visible light L1 emitted from the light source device 35. The color wheel 10 is rotated by, for example, 60 to 120 rotations / second in a clockwise direction by a driving unit 18 connected to a central shaft, so that white light (W light), red light (R light), green light (G light) and The visible light L1 is time-divided into one of the blue light (B light) and is split into the colored light L2.
In the projector device 30, the colored light L <b> 2 that has passed through the color wheel 10 is emitted from the rod lens 31 as equal luminance light L <b> 3 with uniform illuminance at the cross section. Then, it becomes condensed light L4 through the integrator lens 32, and the image light L5 formed by modulating the condensed light L4 in the display device 33 such as DMD is enlarged and projected on the screen (not shown) by the projection lens 34. Is done.

The light source device 35 will be described in detail. The light source device 35 has a discharge lamp 35a that emits white light and a light reflecting surface that has a spheroidal shape centered on the optical axis, and reflects the white light from the discharge lamp 35a. The concave reflecting mirror 35b and a radiation window 35c as necessary.
The discharge lamp 35a is not particularly limited as long as it emits white light. For example, an ultrahigh pressure mercury lamp can be used. In the ultra high pressure mercury lamp, for example, a pair of tungsten electrodes are disposed opposite to each other in an arc tube portion, and mercury and halogen are sealed, and a rare gas is appropriately sealed as necessary. As the discharge lamp 35a, it is particularly preferable to use an ultrahigh pressure mercury lamp in which 0.16 mg / mm ³ or more of mercury is enclosed in an arc tube so that the mercury vapor pressure during lighting becomes an ultrahigh pressure.
In addition, a xenon arc discharge lamp, a metal halide discharge lamp, or the like can be used as the discharge lamp 35a.

The projector device 30 changes the input power to the discharge lamp in order to modulate the light output of the colored light transmitted through each segment.
Specifically, in order to increase the light output of the colored light, the input power to the discharge lamp is increased. To reduce the light output of the colored light, the input power to the discharge lamp is decreased. To do.
In order to obtain an image with high color reproducibility suitable for a home theater or the like, the discharge lamp irradiates the specific segment 17b in order to increase the light output of red light (R light) transmitted through the specific segment 17b. The input power is increased compared to when irradiating other segments.

FIG. 5 is an explanatory diagram of the relationship of the input power of the discharge lamp in each segment.
In the figure, the vertical axis represents the input power of the discharge lamp, the horizontal axis represents each segment, R, G, B, and W of each segment, R is colored light is red light, and G is colored light. Means green light, B means colored light is blue light, and W means colored light is white light.
The occupation angle of the segment 17a is 60 °, the occupation angle of the specific segment 17b is 120 °, the occupation angle of the segment 17c is 60 °, and the occupation angle of the segment 17d is 120 °.

As shown in FIG. 5, while the colored light corresponds to the specific segment 17b where the red light is emitted, the input power of the discharge lamp is 90 W which is the maximum value, and the colored light corresponds to the segment 17c where the colored light becomes the green light. During this time, the input power of the discharge lamp is 60 W, and while the colored light corresponds to the segment 17 d where the colored light becomes blue light, the input power of the discharge lamp is 30 W, and the colored light becomes white light. While corresponding to the segment 17a, the input power of the discharge lamp is 60W.
That is, when the input power of the discharge lamp in the specific segment 17b is A, A is 90W.
On the other hand, the average input power of the discharge lamp over all segments is obtained by multiplying the occupancy angle (°) of each segment by the input power of the discharge lamp corresponding to that segment to obtain the occupancy power of each segment. In this implementation, if the average input power of the discharge lamp over all segments is B, then B is 60W.

  In this way, by increasing the input power of the discharge lamp while the colored light corresponds to the specific segment 17b that becomes red light (R light), the light output of the colored light of red light (R light) is increased and red. The light output of light (R light) can be made larger than the light output of other colored lights (G light, B light, W light).

Hereinafter, the transparent substrate 12 will be described in detail.
The specific transparent substrate 12b constituting the specific segment 17b transmits red light (R light) in the wavelength region of 600 to 780 nm and absorbs blue light (B light) in the wavelength region of at least 380 to 500 nm. The blue light (B light) does not return to the discharge lamp as reflected light.

As the specific transparent substrate 12b, glass colored in red or orange (hereinafter also referred to as “colored glass”) or the like can be used.
Colored glass varies depending on the glass components, heating and cooling, melting atmosphere, cooling environment, etc. For example, red glass can be used by adding gold, copper, selenium, etc. as an additive in the glass, and orange glass. Can be produced by adding silver, nickel, carbon or the like as an additive.

  The specific transparent substrate 12b has a light absorptance of 80% or less per 1 mm thickness in light of 380 nm. In this embodiment, the light absorptivity is 80% and the thickness is 0.65 mm.

On the other hand, the translucent substrates 12a, 12c, and 12d other than the specific translucent substrate 12b transmit the light emitted from the discharge lamp 35a of the light source device 35 without absorbing it, and examples thereof include white glass.
The white plate glass varies depending on the components of the glass, heating and cooling, the melting atmosphere, the cooling environment, and the like, but can be obtained, for example, by adding calcium, tin, fluorine or the like as an additive in the glass.

Next, an experiment was conducted to examine the change in the illuminance maintenance factor in relation to the thickness of the specific transparent substrate in the specific segment and the input power of the discharge lamp.
In this experiment, the input power of the discharge lamp is defined as A, the input power (W) of the discharge lamp in a specific segment as A, the average input power (W) of the discharge lamp over all segments as B, and A / B And the thickness T (mm) of the specific transmissive substrate, an experiment was conducted to examine the change in the illuminance maintenance rate.
The illuminance maintenance rate indicates the illuminance after 100 hours relative to the initial illuminance being 100%.

  The cause of the change (decrease) in the illuminance maintenance rate is that the blue light (B light) in the wavelength range of 380 to 500 nm among the light irradiated to the specific segment becomes the return light to the discharge lamp, and this return light is the discharge lamp. When the electrodes are irradiated, the temperature of the electrodes rises and the electrodes melt, so that the distance between the electrodes increases, or the evaporated material from the electrodes adheres to the inner surface of the arc tube, and the discharge lamp itself The illuminance is reduced.

In this experiment, the occupation angle (°) of the specific segment is 120 °, the A / B value is changed from 1.1 to 1.7, and the thickness of the specific transparent substrate is changed from 0.15 mm to 0.85 mm. The illuminance maintenance ratio when changing was examined, and a projector apparatus with an illuminance maintenance ratio of 90% or more was evaluated as good “◯”, and a projector apparatus with less than 90% was evaluated as defective “X”.
The results are shown in FIG.

  From FIG. 6, as the value of A / B increases, that is, as the light output of red light (R light) that is colored light transmitted through a specific segment increases, blue light (B light in a wavelength range of 380 to 500 nm). It can be seen that the thickness T of the specific transparent substrate has to be increased in order to suppress the decrease in the illuminance maintenance rate without returning to the discharge lamp.

FIG. 7 is a graph showing the relationship between the value of A / B and the thickness T (mm) of the specific transmissive substrate for suppressing the decrease in illuminance maintenance rate based on the experimental results shown in FIG. is there.
The thickness T of the specific transmissive substrate is a thickness of the specific transmissive substrate that sufficiently absorbs blue light in the wavelength range of 380 to 500 nm and does not have an illuminance maintenance ratio of less than 90% ("x" in FIG. 5). That is.

From FIG. 7, if the relationship between the thickness T of the specific transmission substrate and the value of A / B satisfies the following formula, the specific transmission substrate can satisfactorily emit blue light (B light) in the wavelength range of 380 to 500 nm. It is possible to absorb the blue light (B light) so as not to return to the discharge lamp, and to suppress a decrease in the illuminance maintenance rate.
(formula)
T ≧ {−0.6 (A / B) ² +3.1 (A / B) −2.4}
From FIG. 7, the relationship between the thickness T of the specific transparent substrate and the value of A / B is an approximate curve, and T ≧ {−0.68 (A / B) ² +3.10 (A / B) −. 2.45}, but the above (formula) is taken in consideration of the error of the experimental result.

  In the above formula, the specific transparent substrate has a light absorption rate of 80% per 1 mm thickness in light of 380 nm, but when the light absorption rate is 80% or less, all of the A / B In value, the thickness of the specific transmissive substrate shifts in the thicker direction, so that the above (formula) is satisfied even when the light absorption rate per 1 mm thickness is 80% or less in the light of 380 nm. is there.

In addition, the above (formula) is when the occupation angle of the specific segment is 120 °, but the adjustment of the light output of the red light (R light) transmitted through the specific segment is performed by changing the occupation angle of the specific segment. The above (formula) changes in relation to the occupation angle of the specific segment.
That is, the above (formula) is a relational expression that is established when the occupation angle of the specific segment is 120 °, but in order to change the light output of the red light (R light) that is the colored light transmitted through the specific segment. Changes the occupying angle of the specific segment. The occupying angle C (°) of the specific segment with respect to the occupying angle C (°) of the specific segment used for the specific segment occupying angle of 120 ° used in the above experiment is C (° ) / 120 (°).

Therefore, since the above (formula) is proportional to the occupation angle (°) of the specific segment, the thickness T (mm) of the specific transparent substrate, the input power A (W) of the discharge lamp in the specific segment, The average input power B (W) of the discharge lamp over all the segments and the occupation angle C (°) of the specific segment satisfy the following Expression 1.
(Formula 1)
T ≧ {−0.6 (A / B) ² +3.1 (A / B) −2.4} × C / 120 °

  Also in the above (Equation 1), when the specific transmission substrate has a light absorptance of 80% or less per 1 mm in thickness at 380 nm, the specific transmission substrate is used for all A / B values. Therefore, even if the light absorptance per 1 mm thickness is 80% or less in 380 nm light, the above (Formula 1) is satisfied.

As a result, if the specific transmission substrate has a thickness in the range obtained from the above (Equation 1), even if the input power to the discharge lamp is increased in order to increase the light output of red light (G light), Of the light irradiated to the specific segment, red light (R light) in the wavelength range of 600 to 780 nm is transmitted well, blue light (B light) in the wavelength range of 380 to 500 nm is absorbed well, Blue light (B light) can be prevented from returning to the discharge lamp, an increase in the electrode temperature of the discharge lamp can be suppressed, and a decrease in illuminance of the discharge lamp itself can be suppressed.
Further, by using a color wheel having a specific transparent substrate having a thickness within the range obtained from the above (Equation 1), the illuminance of the discharge lamp can be maintained high over a long period of time, so that high color reproduction is achieved in the projected image. It becomes a projector device that can be obtained.

  Furthermore, by setting the thickness of the specific transparent substrate to 1 mm or less, it is possible to prevent the color wheel from becoming thick, the color wheel can be disposed at the same position as the conventional position, and further rotated at high speed. The color wheel is not decentered, and the projector device can maintain the optimum rotation state.

35a Discharge lamp 10 Color wheel 12 Translucent substrate 12a Translucent substrate 12b Translucent substrate 12c Translucent substrate 12d Translucent substrate 15a Color filter layer 15b Color filter layer 15c Color filter layer 15d Color filter layer 17a Segment 17b Segment 17c Segment 17d Segment

Claims (2)

A discharge lamp, and a color wheel having a plurality of segments for rotating light from the discharge lamp into colored light according to transmission characteristics by rotating, and changing the input power to the discharge lamp to change the color of each colored light. In a projector device that modulates light output,
The color wheel has a translucent substrate and a plurality of color filter layers that partition the segments formed on the light emitting side surface of the translucent substrate,
One of the color filter layers is a specific color filter layer that transmits light in a wavelength region of 600 to 780 nm,
The translucent substrate facing the specific color filter layer is a specific translucent substrate that absorbs light in a wavelength range of 380 to 500 nm,
Among the plurality of segments, a segment is defined as a specific segment from a combination of the specific color filter layer and the specific transparent substrate,
The specific transmission substrate constituting the specific segment has a light absorption rate of 80% or less per 1 mm thickness in light of 380 nm, and a thickness T satisfies the following (formula 1): Projector device.
(Formula 1)
T ≧ {−0.6 (A / B) ² +3.1 (A / B) −2.4} × C / 120 °
T is the thickness of the specific transparent substrate (mm)
A is the input power (W) of the discharge lamp in a specific segment
B is the average input power (W) of the discharge lamp across all segments
C is the occupancy angle of a specific segment (°)   The projector device according to claim 1, wherein a thickness T of the specific transparent substrate is 1 mm or less.

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