Projector system

Abstract

We provide a projector system that offers excellent installation flexibility and does not interfere with operation or video viewing. [Solution] The projector system 1 includes a projector 100 that outputs an image and a screen 200 that displays the image output by the projector 100. The projector 100 outputs an image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue. The screen 200 is transparent and includes a first filter 210 that reflects light having the frequency characteristic consisting of the waveform and transmits light having a frequency characteristic excluding the waveform.

Description

Technical Field

[0001] The present disclosure relates to a projector system, and more particularly to a projector system capable of displaying an image output by a projector.

Background Art

[0002] Today, a projector system has been proposed in which a screen is installed on the ceiling of a vehicle or the like, and light from a projector is projected onto the screen from the rear side of the vehicle to display an image or the like on the screen.

[0003] Recently, a projector system has been proposed that uses a semi-transmissive screen to display an image on the screen while allowing the user to grasp the situation on the other side of the screen (the front side of the vehicle and its surroundings). By using a semi-transmissive screen, a user sitting in the rear seat can enjoy the image displayed on the screen while unconsciously perceiving the surrounding situation by the light transmitted through the back of the screen (light transmitted from the front side of the vehicle to the rear side). Therefore, the sense of blockage of the rear seat due to the presence of the screen can be reduced.

[0004] However, in such a projector system, locally strong light among the light of the projector irradiated on the screen may reach the rearview mirror through the screen. In this case, the locally strong light among the light of the projector may be reflected by the rearview mirror and enter the driver's field of vision, causing glare. Also, when the driver looks back rearward for rearward confirmation or the like, there is a risk that locally strong light among the light of the projector transmitted through the screen may directly enter the eyes. In this way, a region that is locally bright and visually recognized as a spot among the light of the projector is called a hot spot. When the driver visually recognizes the hot spot when looking through the rearview mirror or directly at the screen by looking back, there is a problem that it hinders normal driving operations such as safety confirmation.

[0005] For this reason, improved projector systems have been proposed to prevent light projected onto a screen from the rear of the vehicle from entering the driver's field of vision (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 05-294189 [Overview of the project] [Problems that the invention aims to solve]

[0007] The improved projector system uses two transparent plates to support multiple thin screen panels, allowing for adjustment of both the screen's angle and the angle of the individual screen panels. This configuration makes it possible for rear-seat passengers to perceive the gaps between the multiple screen panels as a single screen, and to display images on this screen. From the front-seat passenger's (driver's, etc.) perspective, the multiple screen panels are aligned to form a nearly horizontal surface, allowing them to see behind them through the gaps between the panels.

[0008] However, in order to make the screen visible to front and rear-seat passengers as described above, the range of angle adjustment and setting for the screen itself and the thin screen panels is limited, and the installation position and angle of the projector installed in the vehicle are also restricted. As a result, there was a problem in that the flexibility of the projector system's installation was significantly reduced.

[0009] Furthermore, because of the constraints on the placement and angle of the screen and projector, the optimal viewing position (height, angle, etc.) for users sitting in the back may be predetermined. As a result, tall or short people may find their viewing position outside the predetermined range when seated comfortably in the back, making it difficult to view the screen image.

[0010] This disclosure is made in view of the above-mentioned problems, and aims to provide a projector system that offers excellent installation flexibility and does not interfere with operation or video viewing. [Means for solving the problem]

[0011] To solve the above problems, the projector system in the first embodiment is a projector system having a projector installed in the rear part of a vehicle that outputs an image, and a screen installed in the central part of the vehicle that displays the image output by the projector, wherein the projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue, and the screen is characterized by having transparency and a first filter that reflects the light having the frequency characteristic consisting of the waveform and transmits light having a frequency characteristic other than the waveform.

[0012] The projector system in the second embodiment is a projector system having a projector installed in the rear part of a vehicle that outputs an image, and a rearview mirror used in the driver's seat to check the rear of the vehicle, wherein the projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue, and the rearview mirror is equipped with a second filter that blocks the light having the frequency characteristic consisting of the waveform and reflects light having a frequency characteristic excluding the waveform.

[0013] The projector system in the third embodiment is a projector system having a projector installed in the rear part of a vehicle that outputs an image, a screen installed in the central part of the vehicle that displays the image output by the projector, and a rearview mirror used in the driver's seat to check the rear of the vehicle, wherein the projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue, the screen has a transmission performance and includes a first filter that reflects the light having the frequency characteristic consisting of the waveform and transmits light having a frequency characteristic other than the waveform, and the rearview mirror includes a second filter that blocks the light having the frequency characteristic consisting of the waveform and reflects the light having a frequency characteristic other than the waveform.

[0014] In a projector system according to a fourth embodiment which may be dependent on any of the first to third embodiments, the projector may be equipped with a laser light source for outputting the image. [Effects of the Invention]

[0015] The projector system disclosed herein offers excellent installation flexibility and provides a projector system that does not interfere with operation or video viewing. [Brief explanation of the drawing]

[0016] [Figure 1] This diagram shows the schematic configuration of the projector system. [Figure 2] (a) is a diagram showing the frequency characteristics of light from an LED light source, and (b) is a diagram showing the frequency characteristics of light from a laser light source. [Figure 3] (a) is a diagram showing the filter characteristics of the filter used in the screen, and (b) is a diagram showing the filter characteristics of the filter used in the rearview mirror. [Figure 4](a) is a diagram schematically showing the positional relationship among a projector, a screen, a rearview mirror, a driver M1, and a passenger M2, showing a state where a filter is provided on the screen and the light of the projector is reflected by the filter, and (b) shows a state where the light of the projector reaches the rearview mirror directly without passing through the screen. [Figure 5] (a) is a diagram schematically showing the positional relationship among a projector, a screen, a rearview mirror, a driver M1, and a passenger M2, showing a state where the light of the projector transmitted through the filter provided on the screen is reflected by the room mirror and is visually recognized by the driver M1, and (b) shows a state where the light of the projector is blocked by the filter installed on the room mirror shown in (a).

Embodiments for Carrying Out the Invention

[0017] Hereinafter, an example of the projector system of the present disclosure will be shown and described in detail with reference to the drawings. FIG. 1 is a diagram showing the schematic configuration of the projector system of the present disclosure. The projector system 1 includes a projector 100, a screen 200, and a rearview mirror (room mirror) 300.

[0018] The projector system 1 is installed in a vehicle 500. The projector 100 is provided near the rear of the vehicle on the ceiling 510. The projector 100 is provided with a lens 110 so as to face the front direction of the vehicle, and it is possible to project an image onto the screen surface of the screen 200 in a state where the screen 200 is vertically installed as described later.

[0019] A laser light source is used as the light source of the projector 100. FIG. 2(a) shows the frequency characteristics (wavelength characteristics, spectral distribution characteristics) of light in a general LED (Light Emitting Diode) light source, and FIG. 2(b) shows the frequency characteristics of light by a laser light source.

[0020] Human vision discriminates colors based on the wavelength of light. In the short wavelength range: 400 nm to 500 nm (peak is approximately 430 nm), blue is recognized; in the medium wavelength range: 500 nm to 600 nm (peak is approximately 530 nm), green is recognized; and in the long wavelength range: 550 nm to 650 nm (peak is approximately 560 nm), red (strictly speaking, red close to yellow - green to orange) is recognized.

[0021] Therefore, whether it is the light of the LED light source shown in Fig. 2(a) or the light of the laser light source shown in Fig. 2(b), colors can be discriminated from the projected light based on the intensity (output level) of the frequencies in the above - mentioned short wavelength range, medium wavelength range, and long wavelength range. That is, when light with frequency characteristics composed of these frequency waveforms is projected onto the screen surface, the projected light is recognized as an image (color information).

[0022] Here, as shown in Fig. 2(a), the light of the LED light source has a gentle change in wavelength characteristics, and the frequency widths of the waveforms of red, green, and blue tend to be wide. On the other hand, as shown in Fig. 2(b), the light of the laser light source has a sharp change in wavelength characteristics, and the frequency widths of the waveforms of red, green, and blue tend to be narrow. In the projector 100 according to the embodiment, as described above, since a laser light source is used, it has the feature that the frequency widths of the waveforms of red, green, and blue are narrow, as shown in Fig. 2(b).

[0023] The screen 200 is provided near the center of the ceiling 510 so that the seated person M2 sitting in the back row can comfortably enjoy the image. When using the screen 200, it can be installed (movable) in a state where the screen 200 is vertically suspended with respect to the ceiling 510 (refer to the solid - line part of the screen 200 in Fig. 1). When not in use, the screen 200 can be tilted and stored on the ceiling 510 side (refer to the two - dotted - line part of the screen 200 in Fig. 1).

[0024] The screen 200 is composed of a screen with light transmission properties. The surface of the screen 200 (the screen surface located on the rear side of the vehicle, see Figure 1) is provided with a first filter 210 that reflects and diffuses a portion of light of a specific wavelength (frequency band) and transmits other light. More specifically, the first filter 210 reflects light of a predetermined frequency band including the peaks of red, green, and blue waveforms, and transmits light of other frequencies and frequency bands. The screen 200 includes, in order from the projector 100 side, a diffusion layer (not shown) for displaying the projected light as an image on the screen 200, the first filter 210, and an all-wavelength light absorption layer (not shown) for adjusting the transmittance. The all-wavelength light absorption layer may be omitted.

[0025] Figure 3(a) shows the filter characteristics (reflectance characteristics) of the first filter 210. As shown in Figure 3(a), the first filter 210 has filter characteristics that correspond to the frequency characteristics of the laser light source shown in Figure 2(b). Specifically, it reflects only the light with a narrow frequency width waveform representing blue, light with a narrow frequency width waveform representing green, and light with a narrow frequency width waveform representing red towards the seated person M2 (showing high reflectance), while transmitting light with other frequency characteristics (showing low reflectance).

[0026] Figure 4(a) schematically shows the setup of a screen 200 equipped with a first filter 210 having the filter characteristics shown in Figure 3(a), a projector 100, and a rearview mirror 300, along with a driver M1 and a seated person M2. When a laser beam (image) with the frequency characteristics shown in Figure 2(b) is projected onto the screen surface of the screen 200 by the projector 100, the image projected from the projector 100 (light with frequency widths corresponding to the red, green, and blue waveforms) is reflected by the first filter 210 of the screen 200, making it visible to the seated person M2, as shown in Figure 4(a).

[0027] Here, a diclock filter can be used as an example of the first filter 210. A diclock filter is a filter mainly composed of a dielectric thin film laminated on a glass material or a highly transparent resin material, and utilizes the interference of light to filter a specific frequency width (frequency band). It possesses the properties of transmitting and reflecting light.

[0028] Simply put, to prevent the projection of the image from projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms) from passing through, while allowing other light to pass through, it is sufficient to use a notch filter that has the characteristic of blocking light in a specific frequency band and allowing light in other frequency bands to pass through. However, using a notch filter may cause heat generation in the filter because certain light is not transmitted (blocked), which may lead to performance degradation of the screen 200, etc. For this reason, the use of a notch filter in filter 210 is not recommended.

[0029] By installing the first filter 210 on the screen 200, the seated passenger M2 can see the image projected onto the screen 200 (light with frequency characteristics consisting of red, green, and blue waveforms) through the light reflected by the first filter 210. Therefore, the seated passenger M2 can enjoy the image using the screen 200, just as with a typical projector system. Furthermore, since the screen 200 is a transparent screen, light entering from the front to the rear of the vehicle through the screen 200 passes through the screen 200 and reaches the seated passenger M2. Therefore, by adjusting the transmittance of the light that passes through the screen 200 from the front to the rear of the vehicle, the seated passenger M2 can enjoy the image projected onto the screen 200 by the laser light of the projector 100 while also being able to see what is happening in front of the vehicle, thus avoiding a feeling of confinement in the rear seat.

[0030] Furthermore, the light projected onto the screen 200 by the laser beam of the projector 100, which has frequency characteristics consisting of red, green, and blue waveforms, is reflected by the first filter 210 as shown in Figure 4(a) and is not transmitted to the front seats (front of the vehicle). Therefore, even when the driver M1 directly checks behind the vehicle with their eyes or checks behind the vehicle through the rearview mirror 300, the driver M1 does not see the image projected from the projector 100.

[0031] On the other hand, since the screen 200 is a transparent screen, light other than the light source of the projector 100, such as light that enters the screen 200 from the rear or side of the vehicle through the side windows or rear window of the vehicle, is transmitted (transmitted) through the first filter 210 to the front of the vehicle. Therefore, even when the driver M1 directly checks the rear with their eyes or checks the rear of the vehicle through the rearview mirror 300, they can still check the situation behind and to the sides of the vehicle through the screen 200. Consequently, even when the laser light (image) of the projector 100 is projected onto the screen 200, the driver M1 can reliably perform safety checks and other operations without interfering with normal driving operations.

[0032] Furthermore, since the image projected from the projector 100 is reflected by the filter 210 of the screen 200 and made visible to the seated person M2, the installation position and adjustment range of the screen 200 and projector 100 can be widened. This increases the flexibility when installing the screen 200 and projector 100.

[0033] Although the projector system relating to this disclosure has been described in detail with reference to the drawings above, the projector system of this disclosure is not limited to the configuration of projector system 1 shown in the embodiment.

[0034] For example, as described above, the light projected onto the screen 200 by the laser light of the projector 100, which has frequency characteristics consisting of red, green, and blue waveforms, is reflected by the first filter 210 as shown in Figure 4(a) and is not transmitted to the front seats (front of the vehicle). Therefore, even when the driver M1 directly checks behind the vehicle with their eyes or checks behind the vehicle through the rearview mirror 300, the driver M1 does not see the image projected from the projector 100.

[0035] However, as shown in Figure 2(b), the laser light from the projector 100, consisting of red, green, and blue waveforms, has a certain frequency width in each waveform. Therefore, it may not be completely reflected (blocked) by the first filter 210, and may be partially transmitted, as shown in Figure 5(a).

[0036] In anticipation of such a case, as shown in Figure 5(b), a second filter 310 may be installed on the rearview mirror 300 to block only the image projected from the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms) and reflect other light. Figure 3(b) shows the filter characteristics (reflectance characteristics) of a filter used as the second filter 310. By using the filter shown in Figure 3(b), only the image projected from the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms, see Figure 2(b)) can be blocked.

[0037] By installing a second filter 310 on the rearview mirror 300 that blocks the image projected from the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms), even if the first filter 210 on the screen 200 cannot completely block the image projected by the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms), the second filter 310 can block that light. Therefore, when light transmitted through the screen 200 is reflected by the rearview mirror 300, the reflected light will not contain the image projected by the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms), and the image from the projector 100 will not be visible to the driver M1 through the rearview mirror 300. Even when the laser light from the projector 100 is projected onto the screen 200, the driver M1 can reliably perform safety checks and other actions without any interference with normal driving operations.

[0038] Furthermore, as mentioned above, since the screen 200 can be tilted relative to the ceiling surface 510, depending on the position and angle of the screen 200, there is a possibility that the image projected from the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms) may not pass through the screen 200 but reach the rearview mirror 300 directly, as shown in Figure 4(b).

[0039] Even in such cases, by installing the second filter 310 on the rearview mirror 300, it is possible to prevent the driver M1 from seeing the image from the projector 100 through the rearview mirror 300. Therefore, even if the laser light from the projector 100 reaches the rearview mirror 300 directly, the driver M1 can reliably perform safety checks and other actions through the rearview mirror 300, without interfering with normal driving operations.

[0040] Furthermore, although the projector system 1 according to the embodiment comprises a projector 100, a screen 200, and a rearview mirror 300, the configuration of the projector system of this disclosure is not limited to this configuration.

[0041] For example, the projector system 1 may consist only of a projector 100 and a screen 200, and may not include a rearview mirror 300 at all. If the first filter 210 of the screen 200 can sufficiently reflect the image projected from the projector 100 (light with frequency characteristics consisting of red, green, and blue waveforms), a general-purpose rearview mirror can be used as the rearview mirror 300, and even in this case, the same effect as the projector system of this disclosure can be achieved.

[0042] Furthermore, the projector system of this disclosure can also consist of only a projector 100 using a laser light source and a rearview mirror 300 equipped with a second filter 310. In this case, by installing a general screen as needed, the seated person M2 can enjoy the image projected onto the screen, and because a general screen has a structure that does not transmit (or transmits poorly) the projected image, the driver M1 will not see the light from the laser light source through the rearview mirror 300.

[0043] On the other hand, even if the laser light (image) is accidentally output (projected) from the projector 100 while the screen 200 is stored on the ceiling 510 side, if the filter 310 is provided on the rearview mirror 300, the laser light (image) output from the projector 100 can be blocked by the filter 310. For this reason, any projector system 1 that includes at least the projector 100 and the rearview mirror 300 can achieve the same effect as the projector system disclosed herein. [Explanation of Symbols]

[0044] 1 ... Projector system 100... Projector 110... (Project) Lens 200… screens 210 … (First filter for screen) 300... Rearview mirror 310 … (Second filter for rearview mirror) 500 ... Vehicles 510 … (vehicle) ceiling M1... Driver M2…seated person

Claims

1. A projector installed at the rear of the vehicle that outputs images, A screen installed in the central part of the vehicle, which displays the image output by the projector, A projector system having, The projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue. The aforementioned screen is transparent, The system includes a first filter that reflects light having frequency characteristics consisting of the aforementioned waveform and transmits light having frequency characteristics excluding the aforementioned waveform. A projector system characterized by the following:

2. A projector installed at the rear of the vehicle that outputs images, The rearview mirror, used in the driver's seat to check the area behind the vehicle, A projector system having, The projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue. The aforementioned rearview mirror is The system includes a second filter that blocks the light having frequency characteristics consisting of the aforementioned waveform and reflects the light having frequency characteristics excluding the aforementioned waveform. A projector system characterized by the following:

3. A projector installed at the rear of the vehicle that outputs images, A screen installed in the central part of the vehicle for displaying images output by the projector, The rearview mirror, used in the driver's seat to check the area behind the vehicle, A projector system having, The projector outputs the image based on light having a frequency characteristic consisting of a waveform with a narrow frequency width peak at the frequencies in which humans distinguish red, green, and blue. The aforementioned screen has transparency properties, The system includes a first filter that reflects light having frequency characteristics consisting of the waveform and transmits light having frequency characteristics excluding the waveform. The aforementioned rearview mirror is The system includes a second filter that blocks the light having frequency characteristics consisting of the aforementioned waveform and reflects the light having frequency characteristics excluding the aforementioned waveform. A projector system characterized by the following:

4. The projector is equipped with a laser light source for outputting the image. A projector system according to any one of claims 1 to 3, characterized by the above.

Images