CN218938725U - Projection device - Google Patents

Abstract

The utility model discloses a projection device, comprising: a light source assembly; the first polarizing element is arranged on the light emitting side of the light source assembly and is a linear polarizing element; the display panel is arranged on one side of the first polarizing element, which is far away from the light source assembly, and comprises a liquid crystal layer; the second polarizing element is arranged on one side of the display panel far away from the first polarizing element and is a linear polarizing element; the first lens is arranged on one side of the second polarizing element away from the display panel and is used for gathering emergent light of the second polarizing element; the projection lens is arranged on one side of the first lens far away from the display panel; the quarter wave plate is arranged between the second polarizing element and the first lens.

Description

Projection device

Technical Field

The present utility model relates to the field of display technologies, and in particular, to a projection apparatus.

Background

At present, the projection device is increasingly widely applied to families and businesses, and the projection device is small in size and high in flexibility and is easy to construct multiple use scenes. The automatic focusing and correcting functions of projection support side projection, the projection is pressureless, the projection system can be flexibly used in bedrooms, study rooms, living rooms, outdoor and other scenes, a consumer can create any space into an audio-visual room, and the projection system is strong in use flexibility at any time and any place. In projection devices, thin film transistor liquid crystal display (TFT-LCD) technology is often used.

Crosstalk (crosstalk) is one of the more common phenomena of poor display of TFT-LCDs, and refers to that a picture in one area affects a picture in another area, and distorts the picture. Fig. 1 is a schematic view of a projection screen in which crosstalk occurs in a projection device. As shown in fig. 1, the projection screen in the middle is displayed in white, and the display of the projection screen 2 on the upper side and the display of the projection screen 3 on the lower side are affected, and the crosstalk phenomenon greatly affects the user experience. At present, crosstalk is considered to be caused by abnormal operation of TFTs due to light irradiated to an active layer on a display panel.

Disclosure of Invention

The embodiment of the utility model provides a projection device, which can solve the problem of poor crosstalk of the projection device on the basis of not reducing the light transmittance.

An embodiment of the present utility model provides a projection apparatus, including: a light source assembly; the first polarizing element is arranged on the light emitting side of the light source assembly and is a linear polarizing element; the display panel is arranged on one side of the polarizing component far away from the light source component and comprises a liquid crystal layer; the second polarizing element is arranged on one side of the display panel far away from the first polarizing element, and the second polarizing element is a linear polarizing element; the first lens is arranged on one side of the second polarizing element away from the display panel and is used for gathering emergent light of the second polarizing element; the projection lens is arranged on one side of the first lens far away from the display panel; the quarter wave plate is arranged between the second polarizing element and the first lens.

In an exemplary embodiment, the transmission axis of the first polarizing element is parallel or substantially parallel to the transmission axis of the second polarizing element, or the transmission axis of the first polarizing element and the transmission axis of the second polarizing element are perpendicular to each other.

In an exemplary embodiment, the transmission axis of the second polarizing element forms an angle with the fast axis of the quarter wave plate other than 90 °.

In an exemplary embodiment, an included angle between a transmission axis of the second polarizing element and a fast axis of the quarter wave plate is in a range of 30 ° to 60 °.

In an exemplary embodiment, the angle between the transmission axis of the second polarizing element and the fast axis of the quarter wave plate is 45 °.

In an exemplary embodiment, the second polarizing element is disposed in contact with the display panel, and the quarter wave plate is disposed in contact with the second polarizing element.

In an exemplary embodiment, the quarter wave plate is disposed in registry with the first lens.

In an exemplary embodiment, the first lens is a fresnel lens.

In an exemplary embodiment, the fresnel lens includes a first surface facing the display panel, the first surface being a smooth surface, and a second surface facing away from the display panel, the second surface being a threaded surface; the quarter wave plate is attached to the first surface.

In an exemplary embodiment, a first gap exists between the first lens and the display panel.

In an exemplary embodiment, the display panel includes an array substrate and a counter substrate, the liquid crystal layer being between the array substrate and the counter substrate; the array substrate comprises a thin film transistor.

In an exemplary embodiment, the array substrate is located at a side of the opposite substrate away from the light source assembly.

In an exemplary embodiment, the opposite substrate includes a color film layer.

In an exemplary embodiment, the projection apparatus further includes a second lens located at a side of the first polarizing element near the light source assembly for collimating light emitted from the light source assembly.

In an exemplary embodiment, the projection apparatus further includes a light transmitting portion between the light source assembly and the display panel, and the first polarizing element is attached to a side of the light transmitting portion away from the display panel.

In an exemplary embodiment, the projection apparatus further includes at least one of a first mirror and a second mirror; the first reflector is arranged on one side of the first lens, which is far away from the light source assembly, and is used for reflecting light emitted from the display panel into the projection lens; the second reflector is configured to reflect light emitted from the light source assembly into the display panel.

According to the projection device provided by the embodiment of the utility model, the quarter wave plate is arranged between the second polarizing element and the first lens, so that the reflected light generated by the emergent light which passes through the quarter wave plate and reaches the first lens enters the quarter wave plate again, at least part of the reflected light is blocked by the second polarizing element and cannot enter the display panel, the influence of the reflected light on the operation of the transistor of the thin film transistor in the display panel is reduced or avoided, the temperature rise in the display panel caused by the reflected light is also reduced, the risk of crosstalk failure is greatly reduced, the influence on the light transmittance of the projection device is smaller, and the display effect and the reliability of the projection device are improved.

Additional features and advantages of the utility model will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model. The objectives and other advantages of the utility model may be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate and do not limit the utility model.

FIG. 1 is a schematic diagram of a projection screen in which crosstalk occurs in a projection device;

fig. 2 is a positional relationship of a display panel, a first polarizing element, a second polarizing element, a light transmitting portion, a first lens, and a second lens of the projection apparatus along a light traveling direction in an exemplary embodiment;

FIG. 3 is an optical path diagram of a projection device in an exemplary embodiment;

FIG. 4 is a schematic diagram of a projection apparatus according to an exemplary embodiment;

fig. 5 is a schematic diagram showing changes in polarization directions of light rays in an optical path according to an exemplary embodiment.

Detailed Description

The present utility model has been described in terms of several embodiments, but the description is illustrative and not restrictive, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the described embodiments. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are possible. Any feature or element of any embodiment may be used in combination with or in place of any other feature or element of any other embodiment unless specifically limited.

The present utility model includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The disclosed embodiments, features and elements of the present utility model may also be combined with any conventional features or elements to form a unique inventive arrangement as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive arrangements to form another unique inventive arrangement as defined in the claims. It is therefore to be understood that any of the features shown and/or discussed in the present utility model may be implemented alone or in any suitable combination. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Further, various modifications and changes may be made within the scope of the appended claims.

Furthermore, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other sequences of steps are possible as will be appreciated by those of ordinary skill in the art. Accordingly, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Furthermore, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present utility model.

In the present utility model, the terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, unless otherwise specifically indicated and defined. For example, it may be a fixed connection, a removable connection, or an integral connection; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intermediate members, or may be in communication with the interior of two elements. The meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to circumstances. Wherein "electrically connected" includes the case where constituent elements are connected together by an element having some electric action. The "element having a certain electric action" is not particularly limited as long as it can transmit an electric signal between the connected constituent elements. Examples of the "element having some electric action" include not only an electrode and a wiring but also a switching element such as a transistor, a resistor, an inductor, a capacitor, other elements having one or more functions, and the like.

In the drawings, the size of constituent elements, thicknesses of layers, or regions may be exaggerated for clarity. Accordingly, one embodiment of the present utility model is not necessarily limited to this size, and the shape and size of each component in the drawings do not reflect the true scale. Further, the drawings schematically show ideal examples, and one embodiment of the present utility model is not limited to the shapes, numerical values, and the like shown in the drawings.

The ordinal numbers of "first", "second", "third", etc. in the present specification are provided to avoid mixing of constituent elements, and are not intended to be limited in number. The term "plurality" in the embodiments of the present utility model means two or more.

In the description of the embodiments of the present utility model, the terms "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate an orientation or a positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

For the optical element in the present disclosure, in describing the positional relationship, the meaning that the element a is located on the side of the element B close to the element C can be understood in one of the following ways of understanding, depending on the actual configuration of the optical path: firstly, in the light path, main light passes through the element A and then passes through the element B in the process of going from the element C to the element B; secondly, in the light path, the main light passes through the element A and then the element C in the process of going from the element B to the element C.

For the optical element in the present disclosure, in describing the positional relationship, the meaning that the element a is located on the side of the element B away from the element C can be understood in one of the following ways of understanding, depending on the actual configuration of the optical path: firstly, in the light path, main light passes through the element B and then passes through the element A in the process of going from the element C to the element A; secondly, in the light path, the main light passes through the element B and then the element C in the process of going from the element a to the element C.

In order to keep the following description of the embodiments of the present utility model clear and concise, a detailed description of some known functions and known components have been omitted. The drawings of the embodiments of the present utility model relate only to the structures related to the embodiments of the present utility model, and other structures may refer to the general designs.

The present inventors have found that, in the projection apparatus, a lens is disposed on the light-emitting side of the display panel, and light from the light source sequentially passes through the display panel and the lens to perform projection display, however, a part of the light is reflected after reaching the lens, and the part of the reflected light irradiates the active layer of the thin film transistor on the display panel, and the active layer generates photo-generated carriers under the irradiation of light, so that leakage current (Ioff) is increased, and crosstalk is poor, that is, the part of the reflected light is a main cause of crosstalk. In addition, the temperature is higher in the use process of the projection device, and poor crosstalk is aggravated.

An embodiment of the present utility model provides a projection apparatus, including: a light source assembly; the first polarizing element is arranged on the light emitting side of the light source assembly and is a linear polarizing element; a display panel disposed on a side of the first polarizing element away from the light source assembly, the display panel including a liquid crystal layer; the second polarizing element is arranged on one side of the display panel far away from the first polarizing element, and the second polarizing element is a linear polarizing element; the first lens is arranged on one side of the second polarizing element away from the display panel and is used for gathering emergent light of the second polarizing element; the projection lens is arranged on one side of the first lens far away from the display panel; the quarter wave plate is arranged between the second polarizing element and the first lens.

According to the projection device provided by the embodiment of the utility model, the quarter wave plate is arranged between the second polarizing element and the first lens, so that the reflected light generated by the emergent light reaching the first lens through the quarter wave plate enters the quarter wave plate again, at least part of the reflected light is blocked by the second polarizing element and cannot enter the display panel, the influence of reflected light on the operation of the thin film transistor in the display panel is reduced or avoided, the risk of poor crosstalk is reduced, the influence on the light transmittance of the projection device is small, and the display effect and the reliability of the projection device are improved.

It should be noted that, the operation of the thin film transistor in the display panel is affected by the reflected light, including the effect caused by the reflected light directly or indirectly impinging on the thin film transistor. Indirect illumination includes the effect of light striking the thin film transistor by diffuse reflection and/or scattering after re-striking the display panel. The effect of light striking the thin film transistor includes the generation of leakage current, thereby affecting the normal operation of the individual pixels of the display panel.

For example, the first polarizing element and the second polarizing element are both linear polarizing elements, and the transmission axis of the first polarizing element is parallel or substantially parallel to the transmission axis of the second polarizing element. The vibration transmission axes are approximately parallel, and it is understood that the first polarized light and the vibration transmission axes of the second polarized light element are in the same plane, and the included angle between the vibration transmission axes is not more than 10 degrees.

For example, the first polarizing element and the second polarizing element are linear polarizing elements, and the transmission axes of the first polarizing element and the second polarizing element are perpendicular to each other.

In an exemplary embodiment, the transmission axis of the second polarizing element forms an angle with the fast axis of the quarter wave plate other than 90 °. Thus, the quarter wave plate changes the light transmitted through the second polarizing element into elliptically polarized light. When the elliptical polarized light is reflected by the first lens, the included circular polarized light component (for example, right polarized light) rotates to the opposite direction to the direction before reflection, and after the reflected elliptical polarized light passes through the quarter wave plate and the second polarizing element again, the circular polarized light component in the elliptical polarized light is absorbed by the second polarizing element, so that the influence of reflected light on the operation of the thin film transistor in the display panel is reduced or avoided.

In an exemplary embodiment, an included angle between a transmission axis of the second polarizing element and a fast axis of the quarter wave plate is in a range of 30 ° to 60 °. Thus, the elliptically polarized light contains a higher circularly polarized light component, and the reflected light can be efficiently absorbed.

In an exemplary embodiment, the angle between the transmission axis of the second polarizing element and the fast axis of the quarter wave plate is 45 °. Thus, the quarter wave plate changes the light transmitted through the second polarizing element into circularly polarized light. When the circularly polarized light is reflected by the first lens, the rotation direction of the circularly polarized light component is opposite to that before reflection (for example, the left-handed polarized light is changed into right-handed polarized light), and the reflected circularly polarized light is absorbed by the second polarizing element after passing through the quarter wave plate and the second polarizing element again, so that the influence of the reflected light on the work of the thin film transistor in the display panel is avoided.

In an exemplary embodiment, the second polarizing element is disposed in contact with the display panel, and the quarter wave plate is disposed in contact with the second polarizing element. Thus, the integration level of the projection device is high.

In an exemplary embodiment, the quarter wave plate is disposed in registry with the first lens. Thus, the integration level of the projection device is high.

In an exemplary embodiment, the quarter wave plate is attached to the first lens, and the second polarizing element is attached to the quarter wave plate, so that the integration level of the projection device is high.

In an exemplary embodiment, a first gap exists between the display panel and the first lens. For example, the first gap is disposed between the quarter wave plate and the first lens. For example, the first gap is provided between the quarter wave plate and the first polarizing element. For example, the first gap is provided between the display panel and the first polarizing element. Therefore, the first gap can be used as a heat dissipation space or a heat dissipation air duct to timely take away heat, so that the reliability of the projection device is improved.

In an exemplary embodiment, the first lens is a fresnel lens.

In an exemplary embodiment, the fresnel lens includes a first surface facing the display panel, the first surface being a smooth surface, and a second surface facing away from the display panel, the second surface being a threaded surface; the quarter wave plate is attached to the first surface.

In an exemplary embodiment, the display panel includes an array substrate and a counter substrate, the liquid crystal layer being between the array substrate and the counter substrate; the array substrate comprises a thin film transistor.

In an exemplary embodiment, the array substrate is located at a side of the opposite substrate away from the light source assembly.

In an exemplary embodiment, the opposite substrate includes a color film layer. For example, the opposite substrate further comprises a black matrix layer, and the orthographic projection of the black matrix layer on the array substrate covers the active region of the thin film transistor, so that display abnormality caused by direct irradiation of incident light emitted from the light source component on the active region of the thin film transistor is prevented.

In an exemplary embodiment, the projection apparatus further includes a second lens located at a side of the first polarizing element near the light source assembly for collimating light emitted from the light source assembly.

In an exemplary embodiment, the projection apparatus further includes a light transmitting portion between the light source assembly and the display panel, and the first polarizing element is attached to a side of the light transmitting portion away from the display panel.

In an exemplary embodiment, the projection apparatus further includes at least one of a first mirror and a second mirror; the first reflector is arranged on one side of the first lens, which is far away from the light source assembly, and is used for reflecting light emitted from the display panel into the projection lens; the second reflector is configured to reflect light emitted from the light source assembly into the display panel. The first mirror and the second mirror facilitate the downsizing of the projection apparatus.

The display panel of the present utility model will be described in detail below.

Fig. 2 schematically illustrates a positional relationship of a display panel, a first polarizing element, a second polarizing element, a light transmitting portion, a first lens, and a second lens of a projection apparatus according to some exemplary embodiments of the present disclosure along a light traveling direction; fig. 3 schematically illustrates, in a simplified manner, an optical path diagram of a projection apparatus according to some exemplary embodiments of the present disclosure. Referring to fig. 2 and 3 together, the projection device includes: a light source assembly 2, a first polarizing element POL1, a second polarizing element POL2, a display panel PNL, a first lens LNS1, a second lens LNS2, and a quarter wave plate 4.

Wherein the first polarizing element POL1 is disposed at the light-emitting side of the light source assembly 2, for converting light emitted from the light source assembly 2 into first polarized light having the first polarization direction. The first polarizing element POL1 is a linear polarizing element.

For example, the light source assembly 2 includes the light emitting element 22 and the condensing lens 23, and the light emitted by the light emitting element 22 is condensed by the condensing lens 23 and then emitted, so that the light emitting utilization rate of the light source assembly 2 can be effectively improved.

The display panel PNL is disposed on a side of the first polarizing element POL1 away from the light source assembly 2, for adjusting a polarization state of the first polarized light and emitting light. Wherein the display panel comprises a liquid crystal layer.

The first lens LNS1 is disposed at a side of the display panel PNL remote from the light source assembly 2.

The second polarizing element POL2 is disposed at a side of the display panel PNL remote from the first polarizing element POL 1. The second polarizing element POL2 is a linear polarizing element. In some exemplary embodiments, the second polarizing element POL2 is a polarizing film and is attached to the light-emitting surface of the display panel PNL.

In some exemplary embodiments, the vibration transmission axis of the first polarizing element POL1 is parallel or substantially parallel to the vibration transmission axis of the second polarizing element POL 2.

In some exemplary embodiments, the first polarization element POL1 and the second polarization element POL2 are perpendicular to each other in their vibration transmission axes.

In some exemplary embodiments, the first polarizing element POL1 is a polarizing film and is attached to the light incident surface of the display panel PNL. In other exemplary embodiments, there is a space between the first polarizing element POL1 and the display panel PNL, so that heat generated by the first polarizing element POL during filtering is difficult to be conducted to the display panel PNL, and the display effect is not affected due to the excessively high temperature of the liquid crystal display panel.

In some exemplary embodiments, the quarter wave plate 4 is disposed between the second polarizing element POL2 and the first lens LNS 1. For example, the quarter wave plate 4 is bonded to the second polarizing element POL 2. For example, a first gap d1 exists between the quarter wave plate 4 and the second polarizing element POL2, and the first gap d1 can be used as a heat dissipation space or a heat dissipation air duct to timely take away heat, so as to improve reliability of the projection device.

In some embodiments, the projection device further comprises a light transmitting portion GLS. For example, the first polarizing element POL is a polarizing film material and is bonded to the light-transmitting portion GLS. The light transmitting portion GLS is spaced from the display panel PNL, so that a space exists between the first polarizing element POL1 and the display panel PNL, and heat generated by the first polarizing element POL1 during filtering is prevented from affecting the operation of the display panel PNL. The material of the light-transmitting portion GLS is, for example, glass; the material of the light-transmitting portion GLS may play a role of heat insulation, for example.

In some embodiments, the two side surfaces of the light-transmitting portion GLS are planar, and the light does not converge or diverge before and after passing through the light-transmitting portion GLS; it is understood that the light-transmitting portion GLS does not function as an optical lens.

In some embodiments, the first polarizing element POL1 is attached to a side of the light-transmitting portion GLS away from the display panel PNL, so that heat generated by light received by the first polarizing element POL1 is prevented or reduced from being transferred to the display panel PNL by blocking of the light-transmitting portion GLS, and the display effect is prevented from being affected. In some embodiments, the first polarizing element POL1 may be attached to a side of the light-transmitting portion GLS near the display panel PNL.

In some embodiments, the display panel PNL includes an array substrate and a counter substrate, and the counter substrate may be, for example, a color film substrate, where the second polarizing element POL2 is located at a side of the array substrate away from the color film substrate. For example, the second polarizing element POL2 is attached to the array substrate. For example, the second polarizing element POL2 is located at the light emitting side of the display panel, and the projection light transmitted through the display panel PNL is emitted through the color film substrate and then through the array substrate, so that the heat collected on the surface of the color film substrate can be reduced, the surface temperature of the display panel is reduced, and the display panel is protected.

In some embodiments, as shown in fig. 2, the first lens LNS1 is disposed on a side of the display panel PNL away from the light source assembly 2, the light-transmitting portion GLS is located between the light source assembly 2 and the display panel PNL, and a second gap d2 is provided between the light-transmitting portion GLS and the display panel PNL. The second gap d2 can be used as a heat dissipation space or a heat dissipation air duct to timely take away heat, so that the reliability of the projection device is improved.

In some exemplary embodiments, as shown in fig. 2, the second gap d2 may be a gap located at the light emitting side of the light transmitting portion GLS and disposed adjacent to the light transmitting portion GLS; in other exemplary embodiments, the first polarizing element POL1 is attached to the light emitting side of the light transmitting portion GLS, and the second gap d2 is a gap located on the light emitting side of the first polarizing element POL1 and disposed adjacent to the first polarizing element POL 1. It should be noted that the two are immediately adjacent to each other, and no other element is included between the two.

Specifically, the first lens LNS1 is a convex lens. In some embodiments, the first lens LNS1 may be a fresnel lens or an aspherical mirror, preferably a fresnel lens.

In some embodiments, the display device further comprises a first mirror MR1, the first mirror MR1 being arranged to reflect light exiting the display panel PNL into the projection lens 3. Specifically, the first mirror MR1 is disposed on the side of the display panel PNL away from the light source assembly 2, and the first mirror MR1 is disposed on the side of the first lens LNS1 away from the light source assembly 2. The second mirror MR2 may be a planar mirror.

In some embodiments, the first lens LNS1 is located between the first mirror MR1 and the second polarizing element POL 2. In this way, the light emitted from the display panel PNL sequentially passes through the second polarizing element POL2, the first lens LNS1, and the first mirror MR1, and then enters the projection lens, and then emits and forms an image from the projection lens.

In some embodiments, the display device includes a second mirror MR2, and the second mirror MR2 is configured to reflect light emitted from the light source assembly 2 into the display panel PLN. The second mirror MR2 may be a planar mirror.

In some embodiments, the display device includes a second lens LNS2, where the second lens LNS2 is located between the second reflector MR2 and the display panel PLN, and is used to collimate the light reflected by the second reflector MR2, so that the light source assembly 2 is a collimated light source assembly.

In some exemplary embodiments, the second lens LNS2 is located at a side of the light-transmitting member GLS remote from the display panel PLN.

In some exemplary embodiments, the second lens LNS2 is located between the first lens LNS1 and the light source assembly 2.

Specifically, the second lens LNS2 is a convex lens. In some exemplary embodiments, the second lens LNS2 may be a fresnel lens or an aspherical mirror, preferably a fresnel lens.

Fig. 4 is a schematic structural view of a projection apparatus according to an exemplary embodiment. Only part of the structure of the projection device and the display panel is illustrated in fig. 4. As shown in fig. 4, the projection apparatus includes a display panel, a second polarizing element POL2, and a quarter wave plate 4 stacked in this order. Wherein the X direction is the extending direction of the display panel, and the Y direction is the thickness direction of the display panel. For example, the display panel, the second polarizing element POL2, and the quarter wave plate 4 are laminated in this order. Referring to fig. 4, L1 is an incident ray and L2 is an outgoing ray. The incident light L1 includes collimated light from the light source assembly 2.

In an exemplary embodiment, the display panel may include an array substrate 304 and a counter substrate 301, and a liquid crystal layer 302 between the array substrate 304 and the counter substrate 301, the array substrate 304 may include a plurality of thin film transistors 33, and the counter substrate 301 may include a color film layer. In an exemplary embodiment, the array substrate 304 may be located at a side of the opposite substrate 301 remote from the light source assembly 2.

Fig. 5 is a schematic diagram showing changes in polarization directions of light rays in an optical path according to an exemplary embodiment. The X direction is the extending direction of the display panel, and the Y direction is the thickness direction of the display panel. In fig. 5, the angle between the transmission axis of the second polarizing element POL2 and the fast axis of the quarter-wave plate 4 is 45 °.

As shown in fig. 5, the light emitted from the light source 2 may be natural light, and after passing through the first polarizing element POL1, the light is converted into linearly polarized light having the first polarization direction. After passing through the liquid crystal layer 302 of the display panel and the second polarizing element POL2, if light is transmitted (for example, when the gray level is 255), the transmitted light is linearly polarized light in the second polarization direction. The second polarization direction may be parallel or substantially parallel to the first polarization direction, or the second polarization direction may be perpendicular to the first polarization direction, depending on the design of the projection device. After passing through the quarter wave plate 4, the light becomes circularly polarized light (e.g., left circularly polarized light). The light ray continues to move to the first lens LNS1 located at the light emitting side of the display panel, where the first lens LNS1 may be, for example, a fresnel lens, a part of the light ray passes through the first lens LNS1 to perform projection display, and another part of the light ray is reflected by the first lens LNS1, and after being reflected by the first lens LNS1, the handedness of the partially reflected light ray changes (for example, changes into right-handed circularly polarized light). After the reflected light passes through the quarter wave plate 4, the polarization direction of the light becomes perpendicular to the direction of the second vibration transmission axis of the second polarizing element POL2, and the reflected light is blocked by the second polarizing element POL2 and cannot enter the display panel further, thereby reducing or avoiding display anomalies.

It should be noted that, in fig. 5, the light and the Y axis form a certain included angle, which is for illustrating the schematic light path principle, and in practical application, the light and the Y axis may be parallel.

Although the embodiments of the present utility model are described above, the embodiments are only used for facilitating understanding of the present utility model, and are not intended to limit the present utility model. Any person skilled in the art can make any modification and variation in form and detail without departing from the spirit and scope of the present disclosure, but the scope of the present disclosure is defined by the appended claims.

Claims (16)

1. A projection apparatus, comprising: a light source assembly;

the first polarizing element is arranged on the light emitting side of the light source assembly and is a linear polarizing element;

a display panel disposed on a side of the first polarizing element away from the light source assembly, the display panel including a liquid crystal layer;

the second polarizing element is arranged on one side of the display panel far away from the first polarizing element, and the second polarizing element is a linear polarizing element;

the first lens is arranged on one side of the second polarizing element away from the display panel and is used for gathering emergent light of the second polarizing element;

the projection lens is arranged on one side of the first lens far away from the display panel;

the quarter wave plate is arranged between the second polarizing element and the first lens.

2. The projection apparatus according to claim 1, wherein the transmission axis of the first polarizing element is parallel or substantially parallel to the transmission axis of the second polarizing element, or,

the vibration transmission axis of the first polarizing element is perpendicular to the vibration transmission axis of the second polarizing element.

3. The projection apparatus according to claim 1, wherein the transmission axis of the second polarizing element forms an angle other than 90 ° with the fast axis of the quarter wave plate.

4. The projection apparatus according to claim 1, wherein an angle between a transmission axis of the second polarizing element and a fast axis of the quarter wave plate is in a range of 30 ° to 60 °.

5. The projection apparatus according to claim 1, wherein an angle between a transmission axis of the second polarizing element and a fast axis of the quarter wave plate is 45 °.

6. The projection apparatus according to any one of claims 1-5, wherein the second polarizing element is disposed in contact with the display panel and the quarter wave plate is disposed in contact with the second polarizing element.

7. The projection apparatus of any of claims 1-5, wherein the quarter wave plate is positioned in registry with the first lens.

8. The projection device of claim 7, wherein the first lens is a fresnel lens.

9. The projection device of claim 8, wherein the fresnel lens includes a first surface facing the display panel and a second surface facing away from the display panel, the first surface being a smooth surface and the second surface being a threaded surface; the quarter wave plate is attached to the first surface.

10. The projection apparatus according to any one of claims 1-5, wherein a first gap exists between the first lens and the display panel.

11. The projection apparatus according to any one of claims 1 to 5, wherein the display panel includes an array substrate and a counter substrate, the liquid crystal layer being located between the array substrate and the counter substrate; the array substrate comprises a thin film transistor.

12. The projection apparatus according to claim 11, wherein the array substrate is located at a side of the opposite substrate away from the light source assembly.

13. The projection apparatus according to claim 11, wherein the counter substrate comprises a color film layer.

14. The projection apparatus according to any one of claims 1-5, wherein the projection apparatus further comprises a second lens located on a side of the first polarizing element adjacent to the light source assembly for collimating light emitted by the light source assembly.

15. The projection apparatus according to any one of claims 1 to 5, wherein the projection apparatus further comprises a light transmitting portion between the light source assembly and the display panel, and the first polarizing element is attached to a side of the light transmitting portion away from the display panel.

16. The projection device of any of claims 1-5, wherein the projection device further comprises at least one of a first mirror and a second mirror;

the first reflector is arranged on one side of the first lens, which is far away from the light source assembly, and is used for reflecting light emitted from the display panel into the projection lens;

the second reflector is configured to reflect light emitted from the light source assembly into the display panel.

Images