JPH10232379A - Projection type optical device - Google Patents

Projection type optical device

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Publication number
JPH10232379A
JPH10232379A JP9035303A JP3530397A JPH10232379A JP H10232379 A JPH10232379 A JP H10232379A JP 9035303 A JP9035303 A JP 9035303A JP 3530397 A JP3530397 A JP 3530397A JP H10232379 A JPH10232379 A JP H10232379A
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JP
Japan
Prior art keywords
liquid crystal
display element
γ
light source
δ
Prior art date
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Pending
Application number
JP9035303A
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Japanese (ja)
Inventor
Yoshiharu Oi
Minoru Sekine
好晴 大井
実 関根
Original Assignee
Asahi Glass Co Ltd
旭硝子株式会社
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Application filed by Asahi Glass Co Ltd, 旭硝子株式会社 filed Critical Asahi Glass Co Ltd
Priority to JP9035303A priority Critical patent/JPH10232379A/en
Publication of JPH10232379A publication Critical patent/JPH10232379A/en
Pending legal-status Critical Current

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Abstract

(57) [Summary] To provide a very small projection type optical device. A light source, a reflecting mirror, a uniformizing lens, dichroic mirrors, and projection lenses.
3. The liquid crystal display device 8 including the housing 14 and having the reflection surface 9 has an intersection angle γ between the central optical axis and the illumination optical axis of the display surface of the liquid crystal display element 8 of 5 ° and an intersection angle δ of the imaging optical axis and the central optical axis of 5 °, the angle α at which the aperture stop 4 is viewed from the center of incidence on the display surface is 5 °, the angle β at which the aperture stop 11 is viewed from the center of emission is 5 °, and the collimator lens 7
The focal length f C and 100mm of.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type optical device in which a transmission / scattering type display element is constituted by a reflection type.

[0002]

2. Description of the Related Art The purpose of a projection type optical device is to project an image on a screen which is separated by a certain distance, and to obtain a large projected image as compared with a direct view type optical device. For example, a projector basically has a similar structure. That is, the structure of a projection optical device that modulates strong light supplied from a light source with image data and projects the modulated light through a lens optical system has been known for a long time.

There are various optical elements as light modulating means used in a projection type optical device. As an optical element having a scattering property, a suspension display element, a laser writing mode liquid crystal element, a liquid crystal element of dynamic scattering (DSM) and the like have been conventionally known.

[0004] SID Proceedings Vol. 18
/ 2 Second Quarter 1977, pp. 134-146, "Projection System for Light Valve" (Conventional Example 1) discloses a description of a projection optical device in which various light modulating means and a schlieren optical system are combined. As a light modulating means, a PLZT or a liquid crystal element is exemplified, and this is a projection optical device combined with a Schlieren optical system. The reflection mode configuration is shown in FIGS.

Japanese Patent Application Laid-Open No. 5-196923 discloses an invention using a liquid crystal element having a new operation mode in a projection optical device.
No. 1 (conventional example 2) and JP-A-7-5419 (conventional example 3). The liquid crystal elements employed in Conventional Examples 2 and 3 are called liquid crystal / polymer composite elements, polymer / dispersion type liquid crystal elements, or simply dispersion type liquid crystal elements (hereinafter also referred to as LC / PC). It has high scattering performance and transmittance when driven, and has a light absorption type twist
Brighter and higher-contrast display can be performed than a nematic (TN) liquid crystal element or a super twisted nematic (STN) liquid crystal element.

In the conventional example 2, the LC / PC is configured as a reflection type liquid crystal display element to form a reflection type projection type liquid crystal optical device. In Conventional Example 3, projection display is performed by three reflective LC / PC elements arranged so as to sandwich two dichroic mirror surfaces arranged in a delta type.

Further, a color using a reflection type liquid crystal optical element as a reflection type element and using three reflection type display elements for modulating each color light after separating a white light source into three colors of BGR. Projection type liquid crystal display devices were known (for example,
FIG. 5 of JP-A-4-142528 (conventional example 4),
JP-A-4-232917 (conventional example 5)
Figure).

In each of these known examples, an elliptical mirror is used as a condensing mirror of a light source optical system, and divergent light emitted from the light source optical system is collimated by one convex lens, and then three transmission scattering type light beams. It is incident on the reflective element of the liquid crystal optical element. Here, a dichroic prism that intersects at 45 ° with each other was used as a color separation / synthesis system between the convex lens for parallelizing light and the reflective element.

[0009]

In these known examples, a space is required between the projection lens and the parallelizing convex lens and between the illumination optical system and the parallelizing convex lens, so that the volume of the projection type liquid crystal display device is reduced. Cause an increase.

Further, since the incident light and the reflected light of the reflection type liquid crystal optical element enter and reflect at a certain angle with respect to the reflection surface of the reflection type liquid crystal optical element instead of the same optical axis, the reflection type liquid crystal optical element is effective. In order to use light without loss corresponding to the surface, the effective surface of the color separation / combination system and the convex lens for parallelizing light requires a larger area than the reflective surface of the reflective liquid crystal optical element.

Further, in a projection type display device using a liquid crystal display element, when designing a projection lens of the imaging optical system, the projection screen is decentered so that the projection screen can be projected in a direction higher than a horizontal plane on which the optical device is placed. It is common to make an optical design. For this reason, since the center position of the effective screen of the liquid crystal display element is separated from the optical axis of the projection lens, the design effective screen size of the projection lens needs to be designed to be larger than the effective screen size of the liquid crystal display element.

Further, in the case of a reflective projection display device,
As described above, since the illumination optical system and the imaging optical system are arranged on the same side with respect to the reflective liquid crystal display element, this decentered optical design is generally required, and the effective screen size of the projection lens is limited to the liquid crystal display. The effective screen size of the element needs to be considerably increased.

In this case, the projection lens becomes larger than when the projection lens is designed to be coaxial with the center of the screen of the liquid crystal display element, the optical system becomes complicated, and the volume, weight and cost tend to increase. Also, if the size is forcibly reduced, a problem that the illumination optical system and the imaging optical system interfere with each other in a spatial arrangement is caused.

As a means for avoiding these problems, it is conceivable to increase the angle of incidence / reflection of the illumination optical system. Excellent transmission and scattering effects of the element cannot be expected. In this case, in order to reduce the angle of incidence / reflection, an optical path changing prism may be added immediately before the reflective liquid crystal display element, but the optical system becomes more complicated and expensive. It is expected that the performance will decrease due to a decrease in the amount of transmitted or reflected light and an increase in optical aberration.

As another means, it is conceivable to avoid mechanical interference by bending the optical path of at least one of the optical systems. However, this time, a reflecting mirror or a prism which bends the optical system tends to cause mechanical interference. Problems arise.

In recent years, the pixel density of the reflection type liquid crystal element has recently been increased from VGA (640 * 480) to SVGA (800 * 60).
0), 〜XGA (1024 * 868), while higher definition is required, while further reduction in size and weight is required. In order to satisfy both of these, it is advantageous to use a liquid crystal display element having a small liquid crystal display element and a high pixel density, that is, using a liquid crystal display element having a small pixel size and a finer pixel pitch. Due to the stricter requirements, the projection lens system tends to be more complicated and expensive.

In particular, in the case of a TN type liquid crystal display device, it is necessary to increase the incident angle and the reflection angle in order to compensate for the decrease in the amount of light due to a polarizing element or the like. A bright (that is, small F-number) projection lens system is required, which leads to a decrease in resolution, an increase in the number of optical lenses, a complication, etc., and is expected to be a large-sized and expensive reflective liquid crystal display device.

As described above, various types of reflection type liquid crystal display devices have been conventionally proposed. In particular, the transmission / scattering characteristics can be maintained well without increasing the incident angle / reflection angle on the surface of the liquid crystal optical element. A high-density reflective liquid crystal display device that projects an image of a high-density reflective liquid crystal display device on a screen is small, simple, and bright, and can also project a reflective liquid crystal display device having high-density pixels on the screen with good performance. Resolution,
There has been a demand for a reflective liquid crystal display device having high contrast performance.

[0019]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and enlarges a good image on a screen even if the pixel density of the reflective liquid crystal display element is high. An object of the present invention is to provide a reflection-type liquid crystal optical device which can project, is small, lightweight, and has high performance.

That is, according to the first aspect of the present invention, the light source and the first
A light source system provided with an aperture of the above, a light modulation means provided with a display element having a transmission scattering type operation mode and a reflective function layer, and a second aperture provided with a light source light to a display element of light source light. Assuming that the vertical line of the display element surface passing through the central point of incidence is the central optical axis, and the line connecting the central point of emission and the central point of incidence of the light source is the illumination optical axis, the two optical axes have an intersection angle γ, Assuming that a line passing through the emission center point of the element and the center position of the opening of the projection optical system is an imaging optical axis, the imaging optical axis and the central optical axis are, in a plane including both optical axes, an illumination optical axis. A projection-type optical apparatus provided with a projection optical system provided with an eccentric imaging means disposed at an angle δ in the opposite direction and provided with an eccentric imaging means, wherein light emitted from a light source system is made substantially parallel and incident on a display element. Collimator lens that makes the light emitted from the display element form an image in the projection optical system Where α is the angle at which the aperture of the light source system is viewed from the center of incidence of the display element, β is the angle at which the aperture of the imaging optical system is viewed from the center of emission of the display element, and f C is the focal length of the collimator lens. And a projection type optical device characterized by satisfying the relational expression (2).

Here, to convert the light emitted from the light source system into parallel light means that, of the light beams emitted from each point of the light source system, the light beam incident on the central point of incidence of the display element is the main light beam. This means that a light beam emitted with a certain variation from is substantially parallelized with this principal ray.

[0022]

2 ° ≦ γ ≦ 15 ° 2 ° ≦ δ ≦ 15 ° α ≦ 2 ・ γ β ≦ 2 ・ δ 25mm ≦ f C ≦ 175mm

Further, the invention of claim 2 provides that 2 ° ≦ γ ≦ 5
2. The projection type optical device according to claim 1, wherein 50 ° ≦ f C. Further, the invention according to claim 3 is 10 ° ≦
2. The projection optical device according to claim 1, wherein γ ≦ 15 ° and f C ≦ 150 mm. According to a fourth aspect of the present invention, there is provided the projection optical device according to the first, second or third aspect, wherein α ≦ 2 · γ−2 ° and β ≦ 2 · δ−2 °.
According to a fifth aspect of the present invention, there is provided the projection optical device according to the first, second, third or fourth aspect, wherein the liquid crystal / polymer composite element is used for a display element.

[0024]

1 and 2 are a side view and a plan view showing a basic configuration of an example of a projection optical apparatus according to the present invention. In a reflection-type projection optical device that uses a transmission-scattering type liquid crystal display element with a reflection surface provided on one surface thereof, light is emitted from each point of a light source (including a conjugate light source) of an illumination optical system, and the reflection-type liquid crystal display is used. A collimator lens is required to convert the light beam incident on the element parallel to the principal ray, and to focus the light beam reflected by the reflective surface of the reflective liquid crystal display element and emitted to the aperture stop position of the imaging optical system. Become. As an example of the present invention, a plano-convex collimator lens as shown in FIGS. 1 and 2 will be described below.

First, the focal length of the collimator lens is f C , the angle of the opening of the illumination optical system from the center of incidence of the reflection type liquid crystal display element is α, and the optical axis of the reflection type liquid crystal display element and the illumination optical system are conjugate. The distance from the center of the light source is ΔL, the aperture of the aperture stop of the illumination optical system is φ L , the angle from the emission center point of the reflection type liquid crystal display element to the opening of the imaging optical system is β, the optical axis of the reflection type liquid crystal display element And the distance from the center of the aperture stop of the imaging optical system to Δ
A, assuming that the aperture of the aperture stop of the imaging optical system is φ A , γ, α, ΔL, φ L of the illumination optical system and δ, β, ΔA, φ A of the imaging optical system are as follows: The following equation 3 holds.

[0026]

## EQU3 ## (3A): ΔL ≒ f C · tan (γ) (3B): φ L ≒ f C · tan (γ + α / 2) -f C · ta
n (γ-α / 2) (3C): ΔA ≒ f C · tan (δ) (3D): φ A ≒ f C · tan (δ + β / 2) -f C · ta
n (δ-β / 2)

On the other hand, in an optical system of a reflection type projection optical device, as shown in FIGS. 1 and 2, an illumination optical system or a light source system and an image forming optical system are generally provided in a reflection type liquid crystal display element. The optical system is arranged on the same side with respect to the optical axis of the liquid crystal optical element and has optical axes decentered on opposite sides with respect to the optical axis of the liquid crystal optical element.
However, since the aperture stop of the light source system and the aperture stop of the imaging optical system spatially interfere with each other, that is, mechanically collide with a normal arrangement, it is preferable to use Equation (4A) to avoid this. Equation (4A) is further transformed into equations (4B) and (4C).

[0028]

Equation 4] (4A): ΔL-φ L / 2 ≧ 0 and,, ΔA-φ A / 2 ≧ 0 (4B): ΔL-φ L / 2 = f C · tan (γ) -f C ·
{Tan (γ + α / 2) −tan (γ−α / 2)} / 2
≧ 0 (4C): ΔA−φ A / 2 = f C · tan (δ) −f C ·
{Tan (δ + β / 2) -tan (δ−β / 2)} / 2
≧ 0

Here, the inclination γ of the optical axis of the light source system and the inclination δ of the optical axis of the imaging optical system are 2 ° ≦ γ ≦ 15 ° and 2 ° ≦
It is a small angle range of δ ≦ 15 °, and α / 2 and β
Assuming that / 2 is in the same range, the following relationship of Equation 5 is almost satisfied. From this, the relationship of Equation 6 is further derived.

[0030]

(5A): tan (γ) ≒ γ (5B): tan (δ) ≒ δ (5C): tan (γ + α / 2) ≒ γ + α / 2 (5D): tan (γ-α / 2) ≒ γ-α / 2 (5E): tan (δ + β / 2) ≒ δ + β / 2 (5F): tan (δ-β / 2) ≒ δ-β / 2

[0031]

[6] ΔL-φ L / 2 ≒ f C · γ-f C · {(γ + α / 2) - (γ-α / 2)} / 2 = f C · (γ-α / 2) ≧ 0

From the above, it is understood that it is preferable that “α ≦ 2 · γ”. Similarly, it is understood that “β ≦ 2 · δ” is preferable. The above conditions are also preferable for a projection optical device (single-plate full color) in which a liquid crystal display element is displayed as a single panel in color.

Further, as shown in FIG. 1 and FIG.
In a projection optical device having a better color display function using three liquid crystal display elements (three-plate full color),
A space for inserting a dichroic mirror for color separation / synthesis is required between the reflection type liquid crystal display device and the light source system and between the reflection type liquid crystal display device and the imaging optical system. Therefore, f
As a condition of C , it is necessary to take into consideration the above-mentioned angle ranges of γ and δ and at least to have a length equal to or more than the effective diagonal length of the liquid crystal display element to be used.

On the other hand, in order to realize a small projection device including the size of the light source system and the imaging optical system, f C is set to 175 mm or less in the present invention. As described above, in the reflection type projection optical device using the transmission-scattering type liquid crystal display element as defined in claim 1, by satisfying the condition range of claim 1, the characteristics of the transmission-scattering type liquid crystal display element are improved. A small, lightweight and high-performance reflective liquid crystal optical device capable of enlarging and projecting a good image on a screen can be realized.

In the projection type optical device of the present invention, a reflection type projection type optical device is constituted by using an optical element having an operation mode of transmission and scattering as a light modulating means and combining it with other optical elements. In this case, in pixels in the scattering state, light that has reached the back side without being scattered is reflected by the reflective functional layer, and when returning to the optical path, is scattered by passing through the scattering portion in the cell again, resulting in thin light. A high scattering rate can be obtained in the modulation layer. In addition, when the same scattering power is used for the transmission type optical element, the light modulation layer can be formed thin, and as a result, the driving voltage can be reduced.

In the case where the optical element is a display element composed of pixels and is of an active matrix drive system in which an active element is formed for each pixel, it is necessary to use a reflection type when forming a storage capacitor for each pixel. Thereby, the decrease in the pixel aperture ratio due to the formation of the storage capacitor is reduced. Therefore, a high aperture ratio is easily obtained as compared with the transmission type, and the degree of freedom in designing the active element is increased, which is advantageous.

Specifically, it is preferable to use the above-mentioned LC / PC. This is because the scattering state and the transmission state can be directly controlled electrically, a bright light source can be used, and the transmittance of light during transmission can be greatly improved. Further, it is preferable to reduce the light reflectance at the interface between the electrode substrate on the front side of the optical element. This is because a high contrast ratio can be easily obtained. The cell gap of LC / PC is about 8 to 12
If it is set to μm, the drive voltage can be set to 7 to 8V.

The liquid crystal / LC in the LC / PC cell used in the present invention
The specific resistance of the polymer composite layer is preferably 5 × 10 10 Ωcm or more. Furthermore, in order to minimize the voltage drop due to leakage current and obtain a high-definition display, 10
It is more preferably 11 Ωcm or more. In this case, it is not necessary to provide a large storage capacitance for each pixel electrode.

There are various structures of the liquid crystal / polymer composite. In the present invention, in particular, the polymer phase (network structure) formed by communicating a large number of fine pores with the communicating pores And the liquid crystal phase filled in the portion. Liquid crystal and the polymer phase is provided so as to substantially coincide with the ordinary refractive index n o or the extraordinary refractive index n e of the liquid crystal used is the refractive index of the polymer in any state at the time is applied or when no voltage is applied Can be

[0040] The ordinary refractive index n o of the liquid crystal is preferable that substantially matches the refractive index n p of the polymer phase, high transparency at this time an electric field is applied is obtained. N o -0.03 specifically <
it is preferable to satisfy the relationship of n p <n o +0.05.

A voltage is applied between the electrodes of the desired pixel. In the pixel portion to which this voltage is applied, the liquid crystal is arranged in parallel to the direction of the electric field, and the transmissive state is exhibited by the fact that the ordinary light refractive index n o of the liquid crystal matches the refractive index n p of the polymer phase. Light is transmitted through the pixel, and the image is displayed brightly on the projection screen.

[0042] The liquid crystal of the refractive index anisotropy Δn (= n e -n o)
Is preferably larger than a certain level in order to contribute to the scattering property and obtain a high scattering property. Specifically, Δn ≧ 0.18
Is preferable, and Δn ≧ 0.20 is particularly preferable.

It is preferable to use a nematic liquid crystal having a positive dielectric anisotropy. Further, the volume fraction Φ of the liquid crystal is preferably about 60 to 70%, particularly preferably 63 to 67%. Further, it is more advantageous to use a composition in order to satisfy various required performances such as an operating temperature range and an operating voltage required for the liquid crystal.

The LC / PC is sandwiched between a front electrode substrate and a back electrode substrate having a reflection film to form a reflection type liquid crystal optical element. The state of voltage application between the electrodes of the reflective liquid crystal optical element changes the refractive index of the liquid crystal, and changes the relationship between the refractive index of the polymer phase and the liquid crystal. When they match, they are in a transmissive state (light is emitted after regular reflection), and when they are different in refractive index, they are in a scattered state (diffuse light is emitted).

The LC / PC used in the present invention is preferably formed by a photoexcitation polymerization phase separation method. As the material of the polymer phase constituting LC / PC, the use of a photocurable compound as an uncured curable compound is preferable, and among them, the use of a photocurable vinyl compound containing an oligomer is preferable (for example, JP-A-63-271233, 63-
278035 and JP-A-3-98022). Of course, LC / PC by another method can be basically adopted.

The uncured mixture of the liquid crystal and the curable compound contains ceramic particles for controlling the gap between the substrates,
Plastic particles, spacers such as glass fibers, pigments, dyes, viscosity modifiers, and other additives that do not adversely affect the performance of the present invention may be added. The higher the transmittance of the reflective liquid crystal display device using the LC / PC in the transmission state, the better, and the haze value in the scattering state is preferably 80% or more.

When a TFT is used as an active element in the present invention, silicon is suitable as a semiconductor material. In particular, polycrystalline silicon can operate at a higher speed than amorphous silicon, can operate with a TFT having a small area, can achieve a high aperture ratio, and can provide a bright display. Also, a MOS semiconductor substrate can be used as the back electrode substrate. In this case, the driving voltage can be set higher than that of the TFT, and the cell gap can be increased to about 15 μm when driving at 15 V.

[0048]

【Example】

(Example 1) The configuration of this example is as follows. Light source 1, reflecting mirror 2, first aperture stop 4, dichroic mirror 5,
6, collimator lens 7, reflective liquid crystal display element 8, rear lens group 10, second aperture stop 11, relay lens group 1
2. A front lens group 13 is provided, the central optical axis of the display element surface and the illumination optical axis of the light source system have an intersection angle γ, and the imaging optical axis and the central optical axis extending from the display element to the projection optical system. Has an angle δ, an angle at which the first aperture stop 4 of the light source system is viewed from the center of incidence of the display element is α, and a second aperture stop 11 of the imaging optical system is viewed from the center of emission of the display element. The angle is β, and the focal length f C of the collimator lens 7 is set to 25 to 180 mm.

Here, φ L is the aperture of the aperture stop of the illumination optical system, φ A is the aperture of the aperture stop of the imaging optical system, and Δ
L is the distance between the optical axis of the reflective liquid crystal display element and the center of the conjugate light source of the illumination optical system, and ΔA is the distance between the optical axis of the reflective liquid crystal display element and the center of the aperture stop of the imaging optical system. f C is the focal length of the collimator lens. And it is covered with the housing 14. FIGS. 1 and 2 show such a system configuration.

Table 1 shows that f C = 25 mm and γ = 2
°, 5 °, 10 °, 15 °, and δ, like γ, 2
°, 5 °, 10 °, 15 ° and α, β similarly set to (2 °, 5 °, 10 °, 15 °),
And ΔL, ΔA, φ L , φ A , ΔL−φ L / 2, Δ when set to (4 °, 10 °, 20 °, 30 °)
A numerical example of A-φ A / 2 is shown.

Here, the final term H 0 = Σ (ΔLAφ) is
It represents the value of "[Delta] L + [phi] L / 2 + [Delta] A + [phi] A / 2", and indicates the height of the optical system in the side sectional direction including two aperture stops. The actual height of the optical system will be greater than this value.

In the case of Examples 1-a to 1-d in the table, α, β
Are the same as γ and δ and the aperture diameter is not so large, the values of H L = ΔL−φ L / 2 and HA = ΔA−φ A / 2 do not become negative, and the aperture stops overlap. There is no danger and there is no problem. However, in Examples 1-a and 1-d, it is possible to achieve a very small projection display device, which is excellent in that respect, but is considered to be the minimum limit range in terms of brightness.

On the other hand, in Examples 1-e to 1-h, when the values of α and β are each doubled, the value of H 0 is γ,
As δ increases, the value becomes 0 to a slightly negative value, indicating that there is a risk of mechanical interference. That is, f C = 2
If the value of the focal length of the collimator lens is made very small as 5 mm, α, β,
It can be seen that the combination of γ and δ is near the limit of achieving both miniaturization and brightness. Therefore, it is necessary to set f C to 25 mm or more.

In the case of this embodiment, since a reflection type liquid crystal display element having a size of about 1 inch or less can be used, a very small optical unit of about 10 cm in width × 7 cm in depth × 10 cm in height can be realized. Further, since the diagonal length of the display surface is about 1 inch or less, the area is small, and since it is of the reflection type, a high-definition display element utilizing the MOS Si transistor circuit technology can be formed. Table 6 shows this example.
The calculated values of the contrast ratio and brightness of the projected image when a 100 W metal halide lamp was used as the light source were summarized.

As described above, in the case of this example, when a reflection type liquid crystal display device having a small effective surface of the class of 1 inch is used, the size and the brightness are limited.

(Example 2) In Table 2, f C = 100 mm,
Others are numerical examples when the same parameters are used as in Example 1. In the case of Examples 2-a to 2-h, the values of α and β are equal to or twice those of γ and δ, and the height of the optical system in the side sectional direction including the two aperture stops changes. Just by coming, the purpose of being bright and compact can be sufficiently achieved.

However, Example 2-h shows a somewhat negative and non-negligible value, increasing the risk of mechanical interference, and H 0 = Σ (ΔLAφ) also exceeding 100 mm.
An optical system having a considerably high height is obtained for the ratio of f C. In this case, it is preferable to set the opening angles α and β to be slightly smaller by 1 to 2 ° or more.

That is, when the value of the collimator lens is about f C = about 100 mm, the examples of Examples 2-a to 2-g are examples in which downsizing and brightness can be sufficiently realized.

In the case of this example, the configuration is suitable for a reflective liquid crystal display element having a size of about 1 to 2 inches or less. 20cm in width
It is possible to realize a small optical unit of about × 15 cm in depth × 15 cm in height. Also, the diagonal length of the display surface is 1-2.
Since it is about the inch size, it is possible to use an active matrix drive display element driven by a polysilicon TFT formed on a glass substrate, and it is possible to achieve a high-definition display while achieving a reduction in cost of the display element and an improvement in productivity. . Table 7 summarizes the calculated values of the contrast ratio and brightness of the projected image when a 100 W metal halide lamp was used as the light source for this example.

Example 3 In Table 3, f C = 175 mm,
Others are numerical examples when the same parameters are used as in Example 1. In the case of Examples 3-a to 3-c, the values of α and β are equal to γ and δ, there is no mechanical interference, and the height H 0 = Σ.
It can be seen that (ΔLAφ) is also a sufficient size within 100 mm, but this is a minimum example in terms of brightness. On the other hand, in Examples 3-e to 3-f, the brightness and the miniaturization can be sufficiently satisfied, and the miniaturization and the brightness can be reduced even if a reflective liquid crystal display element having a relatively large effective surface of a 3-inch size class is used. It turns out that it is satisfactory.

However, in this example, since f C = 175 mm, H 0 = Σ (ΔLAφ) increases. Above all, in the case of Examples 3-d and 3-h, the height is also high, and especially in the case of 3-h, considering the possibility of mechanical interference,
If the values of α and β are reduced by about 2 ° or more, the projection optical system becomes more reasonable.

That is, this example is an example in which the size and brightness of the optical system according to the present invention are set near the maximum limit. When each element is further increased, the two performances of downsizing and obtaining brightness are compatible. become unable.

In the case of this example, the configuration is suitable for a reflection type liquid crystal display device having a size of about 2 to 3 inches or less. 30cm in width
A small optical unit of about × 20 cm in depth × 20 cm in height can be realized. Further, the diagonal length of the display surface is 2-3.
Since it is about inch size, active matrix drive display elements driven by polysilicon TFTs formed on a glass substrate, especially low-temperature formed poly-Si TFTs in which amorphous Si is polycrystallized at a glass substrate temperature of about 400 ° C. or less by laser annealing. This is preferable because a high-definition display can be achieved, a reduction in cost of the display element, and an improvement in productivity can be achieved.

Further, as compared with the above Examples 1 and 2,
Since the size of the display element is large, the irradiation density on the display surface does not increase even if a high illuminance lamp with large power consumption is used. Therefore, the absolute value of the projected light amount can be improved using the high illuminance lamp.

Table 9 summarizes the calculated values of the contrast ratio and brightness of the projected image when a 200 W metal halide lamp was used as the light source for this example.

(Example 4) In Examples 4-a to 4-d in Table 4, 2 °
≦ γ ≦ 5 °, 2 ° ≦ δ ≦ 5 °, when the eccentric angle is small and f C = 50 mm, α = γ and α =
ΔL, ΔA, φ in the case of 2 · γ, β = δ, β = 2 · δ
L, φ A, ΔL-φ L / 2, ΔA-φ A / 2, H L, H A
, H 0 are shown as numerical examples. Similarly, Examples 4-e to 4-h
In addition, the eccentric angle is small as 2 ° ≦ γ ≦ 5 ° and f C =
An example of a numerical value when 175 mm is set is shown.

From Examples 4-a to 4-d, 2 ° ≦ γ ≦ 5 °,
As can be seen from the values of H L to H 0 when the angle is as small as 2 ° ≦ δ ≦ 5 °, when f C is further reduced, the projection optical device becomes too small and difficult to manufacture. It is expected that. That is, when viewed from easiness of production, it can be said f C = 50 mm position in this example is the lower limit of f C.

On the other hand, in Examples 4-e to 4-h, f C = 17
For 5 mm, for 2 ° ≦ γ ≦ 5 °, and 2 ° ≦ δ ≦ 5 ° smaller, as can be seen from the values of H L to H 0, sufficiently produced easily, and, in the height direction size (In the case of Examples 4-f and 4-h, it may be better to reduce the values of α and β by about 1 to 2 °.) However, considering the horizontal size, f C =
Considering that the length of the projection lens, which is generally about 100 mm, is added to the value of 175 mm, it can be said that this is the larger limit for miniaturization.

That is, as in this example, 2 ° ≦ γ ≦ 5
°, 2 ° ≦ δ ≦ 5 °, the value of f C is 50 m
It is understood that the range of m ≦ f C ≦ 175 mm is preferable.

(Example 5) Examples 5-a to 5-d in
When the declination angle is large such that ° ≦ γ ≦ 15 ° and 10 ° ≦ δ ≦ 15 °, and f C = 25 mm, α =
ΔL in the case of γ, α = 2 · γ, β = δ, β = 2 · δ,
ΔA, φ L, φ A, ΔL-φ L / 2, ΔA-φ A / 2,
Numerical examples of H L , H A , and H 0 are shown. Similarly, Examples 5-e ~
5-h shows a numerical example when the eccentric angle is large, that is, 10 ° ≦ γ ≦ 15 °, and f C = 150 mm.

[0071] From Example 5-a~5-d, in the case of f C = 25mm, 10 ° ≦ γ ≦ 15 °, large as 10 ° ≦ δ ≦ 15 °, if you look at the values of H L to H 0 As can be seen, it can be said that there is no difficulty in the height direction, the production is easy enough, and the miniaturization has been achieved (however, in the case of Examples 5-b and 5-d,
It may be better to reduce the values of α and β by about 1 to 2 °. ).

However, although the size is small, the height direction is higher than the horizontal size, and the lower limit is f C = 25 mm in terms of appearance and stability. On the other hand, the 5-h from Example 5-e, in the case of f C = 150mm, 10 ° ≦ γ ≦ 15 °, large as 10 ° ≦ δ ≦ 15 °, can be seen from the values of H L to H 0 Thus, it can be said that it is easy to manufacture sufficiently (however, in the case of Examples 5-f and 5-h, it may be better to reduce the values of α and β by about 1 to 2 °).

However, in Example 5-h, from the viewpoint of the height direction, it is considered to be the limit of miniaturization. That is, as in this example, 10 ° ≦ γ ≦ 15 ° , 10 ° ≦ δ ≦ 15 if ° and smaller, the value of f C is found to be a preferred range of 25mm ≦ f C ≦ 150mm.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

[Table 3]

[0077]

[Table 4]

[0078]

[Table 5]

[0079]

[Table 6]

[0080]

[Table 7]

[0081]

[Table 8]

[0082]

According to the present invention, it is possible to achieve a projection type optical device which is ultra-compact, can display a bright and high-contrast projected image. The power efficiency of the light source has also been improved,
A practical projection optical device can be manufactured. The present invention can be applied to other uses as long as the effect is not impaired.

[Brief description of the drawings]

FIG. 1 is a side view of a basic configuration of an entire optical system according to the present invention.

FIG. 2 is a plan view of a basic configuration of the entire optical system of the present invention.

[Explanation of symbols]

 1: Light source 2: Reflecting mirror 3: Uniform lens 4: First aperture stop 5, 6: Dichroic mirror 7: Collimator lens 8: Reflective liquid crystal display element 9: Reflecting surface 10: Projection lens (rear lens group) 11: Second aperture stop 12: Projection lens (relay lens group) 13: Projection lens (front lens group) 14: Housing

Claims (5)

    [Claims]
  1. A light source system provided with a light source and a first opening; a light modulating means provided with a display element having a transmission / scattering type operation mode and a reflective function layer; and a second opening. When a perpendicular line of a display element surface passing through a center point of light source light entering the display element is provided as a central optical axis, and a line connecting an emission center point and an incident center point of the light source is an illumination optical axis, both optical axes are provided. Has an intersection angle γ, and assuming that a line passing through the emission center point of the display element and the center position of the opening of the projection optical system is an imaging optical axis, the imaging optical axis and the central optical axis are both optical axes. A projection optical system provided with a projection optical system provided with eccentric imaging means and arranged at an angle δ in a direction opposite to the illumination optical axis in a plane including the illumination light axis, wherein the light emitted from the light source system is provided. Is made almost parallel to be incident on the display element, and the light emitted from the display element is imaged in the projection optical system. Occupied collimator lens is provided, the angle anticipating the opening of the light source system from the incident center point of the display element alpha, corners allow for opening of the image forming optical system from the emission center point of the display device beta, a focal length of the collimator lens f A projection optical apparatus characterized by satisfying the relational expression (1) when C is satisfied. 2 ° ≦ γ ≦ 15 ° 2 ° ≦ δ ≦ 15 ° α ≦ 2 ・ γ β ≦ 2 ・ δ 25mm ≦ f C ≦ 175mm
  2. 2. The projection optical apparatus according to claim 1, wherein 2 ° ≦ γ ≦ 5 ° and 50 mm ≦ f C.
  3. (3) 10 ° ≦ γ ≦ 15 ° and f C ≦ 150 m
    2. The projection optical device according to claim 1, wherein m is m.
  4. (4) α ≦ 2 · γ−2 ° and β ≦ 2 · δ−2 °
    The projection optical device according to claim 1, 2, or 3.
  5. 5. The projection optical apparatus according to claim 1, wherein the liquid crystal / polymer composite element is used as a display element.
JP9035303A 1997-02-19 1997-02-19 Projection type optical device Pending JPH10232379A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9035303A JPH10232379A (en) 1997-02-19 1997-02-19 Projection type optical device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9035303A JPH10232379A (en) 1997-02-19 1997-02-19 Projection type optical device

Publications (1)

Publication Number Publication Date
JPH10232379A true JPH10232379A (en) 1998-09-02

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Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003032049A1 (en) * 2001-10-01 2003-04-17 Matsushita Electric Industrial Co., Ltd. Projection type display unit, rear projector and multi-vision system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003032049A1 (en) * 2001-10-01 2003-04-17 Matsushita Electric Industrial Co., Ltd. Projection type display unit, rear projector and multi-vision system
US6966658B2 (en) 2001-10-01 2005-11-22 Matsushita Electric Industrial Co., Ltd. Projection type display apparatus rear projection and multi-vision system
US7134757B2 (en) 2001-10-01 2006-11-14 Matsushita Electric Industrial Co., Ltd. Projection type display apparatus, rear projection, and multi-vision system
CN1300624C (en) * 2001-10-01 2007-02-14 松下电器产业株式会社 Projection type display unit, rear projector and multi-vision system
US7255450B2 (en) 2001-10-01 2007-08-14 Matsushita Electric Industrial Co., Ltd. Projection type display apparatus, rear projector and multi-vision system

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