CN209746346U - Transparent projection screen based on two-time imaging - Google Patents

Abstract

the utility model discloses a transparent projection screen based on twice formation of image, including screen optical assembly, screen optical assembly includes screen optical component, screen packaging spare, no glass infrared touch screen, and screen optical component includes seamless tiling butt joint's AG glass, holographic projection membrane, PDLC adjustable light membrane, one-way perspective membrane and extra white glass from its orientation projecting apparatus one side to its opposite side in proper order; the glass-free infrared touch screen is arranged on the surface of one side, facing the projector, of the AG glass; the screen packaging piece is packaged around the screen optical component and the glass-free infrared touch screen, and the screen optical component and the glass-free infrared touch screen are sealed and packaged around the screen optical component and the glass-free infrared touch screen. The utility model discloses utilize holographic projection membrane to carry out primary image projection image, utilize PDLC membrane of adjusting luminance to carry out secondary imaging, superpose secondary imaging on primary image, when guaranteeing projection screen perspective effect, reinforcing formation of image effect.

Description

transparent projection screen based on two-time imaging

Technical Field

The utility model relates to a transparent projection screen based on twice formation of image specifically is one kind and is used for under the natural light condition, realizes real-scene augmented reality's adjustable perspective effect and display effect's transparent projection screen, belongs to augmented reality and shows technical field.

Background

as an important human-computer interaction and information display technical means in the near term and in the future, the Augmented Reality technology (AR) is widely applied to the civil, commercial and military fields, and particularly in the industries of aviation, aerospace, ocean engineering, petrochemical industry, communication, construction, advertising, games, travel education and the like, and research and development applications thereof are not well-developed. The AR technology superimposes virtual objects, scenes, and system prompt information generated by a computer, or information from various sensing devices or detecting devices (referred to as enhancement information collectively above) onto a real scene, so that a user obtains additional information while viewing a live-action picture, thereby enhancing reality.

at present, the AR technology is divided from the display technology, and mainly has the following forms: the method is realized through a form of combining a head-mounted display system and a registration (positioning of a user observation point and a computer-generated virtual object) system; and secondly, the real scene is recorded by the camera device, the enhanced information is superposed, and the composite image and the information are displayed by the display screen. And thirdly, the enhanced information is displayed through liquid crystal transparent screens such as OLED (organic light emitting diode) and LCD (liquid crystal display), and is superposed with the real environment behind the screen to realize the purpose. At present, the several implementation modes have many defects in implementation effect, and are greatly limited in practical application. A first mode (head-mounted display), in which a small lens is fixed in a short distance in front of an observer's eye through a head-mounted fixture (generally, a helmet or a spectacle frame), enhanced information is projected onto the lens, and the information is superimposed with a real world real scene seen by the observer through the lens to realize an augmented reality display effect, and the display mode can be worn by only one person, and the device composition is relatively complex, the cost is high, and the user experience in terms of comfort (such as vertigo, poor display effect in case of strong background light, etc.) after wearing is poor, so that the display mode is mainly applied to the professional field at present, and also applied to the commercial high-end field, but not widely, and has few applications in public and engineering aspects; the second mode (camera display) is relatively simple in technology and low in implementation cost, but because various display screens are opaque, the display screens can only show pictures shot by a camera, but cannot simultaneously show the real world environment behind the screen, cannot truly superpose the enhanced information and the pictures of the real world, is influenced by some performances of the camera, has a large discount effect, is widely applied at present, but mainly focuses on simple application of consumer electronic products, and is rarely adopted in the fields of professional field, public and engineering application; although the third mode (transparent screen display) realizes the superposition of enhanced information in the real world, the realization technology is complex, the problems that the prior self-luminous OLED screen has the defects of unpopular transparent screen technology, high cost, large influence by natural light, limited screen size (such as less size specification and difficult customization of the prior OLED screen) and the like exist, and the prior self-luminous OLED screen is greatly limited in practical development and application; however, although the LCD transparent screen widely used in the advertisement box at present has a mature technology and a low price, the LCD transparent screen also has the defects that the real scene generates ghost and halo after perspective due to the multi-layer grating, the screen display enhancement information is dim due to no backlight, and the like, and the LCD transparent screen cannot be overcome, and can only be used in closed environments such as the advertisement box, and the like, and cannot be used in a natural open environment.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem of the existence, the utility model discloses a transparent projection screen based on twice formation of image, its concrete technical scheme as follows:

A transparent projection screen based on twice imaging comprises a screen optical assembly, wherein the screen optical assembly comprises a screen optical component, a screen packaging piece and a glass-free infrared touch screen, the screen optical component sequentially comprises seamless AG glass, a holographic projection film, a PDLC (polymer dispersed liquid crystal) light-adjustable film, a one-way perspective film and ultra-white glass from one side of the screen optical component facing a projector to the opposite side of the screen optical component, the holographic projection film is used for carrying out primary imaging on a projected image and taking the primary imaging as a basic image, transmitted projection light is used for carrying out secondary imaging on the PDLC light-adjustable film again, and the secondary imaging is superposed on the primary imaging to enhance the imaging effect;

The glass-free infrared touch screen is arranged on the surface of one side, facing the projector, of the AG glass;

The screen packaging piece is packaged around the screen optical component and the glass-free infrared touch screen, and the screen optical component and the glass-free infrared touch screen are sealed and packaged around the screen optical component and the glass-free infrared touch screen.

furthermore, the reflectivity of the AG glass is less than or equal to 4%, the light transmittance of the holographic projection film is more than or equal to 99%, the maximum light transmittance of the PDLC light-adjustable film is more than or equal to 88%, the maximum one-way light transmittance of the one-way perspective film is more than or equal to 60%, the light transmittance of the ultra-white glass is more than or equal to 92%, and the comprehensive light transmittance of the augmented reality adjustable transparent projection screen is more than or equal to 47.

Furthermore, no glass infrared touch-sensitive screen includes infra-red transmitter and infrared receiver, is provided with the infra-red transmitter that a plurality of rule was arranged at the top and the left side of AG glass one side, and the opposite side sets up infrared receiver, and each infra-red transmitter all corresponds an infra-red receiver, the infrared ray of infra-red transmitter transmission is at invisible light frequency channel.

furthermore, the PDLC light-adjustable film is connected with a power line, and a power regulator is arranged on the power line.

The utility model discloses the specific use of the adjustable transparent projection screen of augmented reality does: the method specifically comprises the following operation steps:

Step 1: mounting the projector and the projection screen: one side of AG glass of the projection screen faces the projector, one side of ultra-white glass faces outdoors, and an observer watches from the side of AG glass;

step 2: adjusting the transparency of the screen optical assembly: electrifying the screen optical assembly, and adjusting the PDLC light-adjustable film to the maximum transparent state;

and step 3: projection imaging: the light projected by the projector is imaged on the holographic projection film for the first time, when the external light on one side of the ultra-white glass is bright, the haze of the PDLC light-adjustable film is adjusted, the light projected by the projector is imaged on the PDLC light-adjustable film for the second time, and the projection effect and the perspective effect are observed to be in the optimal state;

And 4, step 4: perspective imaging: because the AG glass, the holographic projection film, the PDLC light-adjustable film, the one-way perspective film and the ultra-white glass are all in a transparent state, an observer can observe an outdoor real scene by eyes, and the outdoor real scene is fused with the image obtained in the step 3 and enters the sight of the observer;

And 5: dynamic adjustment: with the change of the direction and the intensity of outdoor light, the haze of the PDLC light-adjustable film is adjusted, so that the projection effect and the perspective effect are observed to be in the best state.

When the utility model discloses the projection screen is used as the scene of two-sided perspective projection screen, its working method is: one side of AG glass of the projection screen faces to the projector, the screen is electrified, the haze of the PDLC light-adjustable film is properly adjusted according to the intensity of ambient light, and the PDLC light-adjustable film is in a transparent state. At the moment, the observer watches from both sides of the projection screen, and the images watched by the observer are superposed images formed by primary imaging and secondary imaging. The imaging effect of both sides is stronger than that of only using the holographic projection film for projection, so that the user can watch the image under the condition of high indoor illumination, which cannot be realized by only using the holographic projection film for one-time imaging.

When the utility model discloses the projection screen is used as the scene of ordinary projection screen, specifically there are two kinds of projection modes as follows:

(1) the positive operation mode: the AG glass side of the projection screen faces the projector, the screen can be not electrified to work or electrified to be adjusted to the maximum haze state, the PDLC light-adjustable film is in the opaque state, an observer watches from the AG glass side, the watched image is a superposed image formed by primary imaging and secondary imaging, and the image is superior to the image formed by only using the holographic projection film, so that the observer can watch under the indoor high-illumination condition, and the point can not be realized by only using the holographic projection film for primary imaging;

(2) the back projection working mode is as follows: the AG glass side of the projection screen faces the projector, and is arranged in a rear projection mode, the screen can be in a non-electrified working state or an electrified and regulated state to the maximum haze, at the moment, the PDLC light-regulating film is in an opaque state, an observer watches from the side of the ultra-white glass, and the image watched is formed by secondary imaging, and in the working mode, the required ambient illumination is low.

The utility model discloses a theory of operation is:

The utility model discloses utilize holographic projection membrane to carry out the primary image formation of image of projection to this is as basic image, and the secondary imaging is carried out at PDLC membrane of can adjusting luminance to the projection light that reuse sees through, superposes the secondary image formation on primary image formation, with reinforcing formation of image effect. The effect of secondary imaging is influenced by the haze of the PDLC light-adjustable film, the higher the haze is, the less the transmitted projection light is, the more diffuse reflection is, the better the imaging effect is, and vice versa. The haze of the PDLC light-adjustable film is stepless adjustable, manual (or automatic) adjustment can be carried out according to the light intensity of one side of the ultra-white glass, when the light intensity of one side of the ultra-white glass is increased, the primary imaging effect can be weakened, reinforcement is needed, the haze of the PDLC light-adjustable film is increased at the moment, the reinforcing secondary imaging effect serves as supplement, meanwhile, the transparency of the PDLC light-adjustable film can be reduced along with the increase of the haze, the light entering from one side of the ultra-white glass (the unidirectional perspective film quantificationally weakens the external light intensity) is further inhibited, and the comprehensive imaging effect is optimal under the precondition that the certain perspective of a screen is guaranteed.

the utility model has the advantages that:

1. the utility model discloses realize directly seeing through the screen and observe real world outdoor scene with perspective projection display mode, can overlap corresponding information or image on the screen again, solve augmented reality's demonstration problem with transparent projection display's mode.

2. The problem that the existing perspective projection can only realize imaging display in a dark environment is solved, single-side projection imaging can be realized in a bright environment, and the transparency and imaging definition of a display screen can be adjusted in a stepless manner.

3. The imaging problem of the perspective projection screen in a backlight environment is solved, the perspective and clear imaging can be realized simultaneously under outdoor strong light, backlight and sun irradiation conditions, and the transparency and the imaging definition of the display screen can be adjusted steplessly according to the intensity of ambient light.

4. The problem of adjustment of perspective projection screen imaging effect under different light conditions is solved.

5. the double-side imaging device can be used for bidirectional transparent and double-side imaging of a projection screen in a dark environment.

6. Can be used as a common projection screen to realize front projection and rear projection.

7. The problem that the existing augmented reality display method cannot meet the special requirements of screen size and shape under special use requirements is solved, and the special requirements of open augmented reality display when the screen is observed from indoor to outdoor are met by customizing the size of a perspective projection screen according to the requirements of customers.

8. The system can be widely applied to industries such as tourism, building, advertisement, transportation and the like, and can be used in the civil and military fields, such as augmented reality display of a ship cab on water surface objects (ships, lighthouses, navigation marks, islands and the like) and a control room; tourist attractions are displayed in an augmented reality manner facing tourists.

Drawings

Figure 1 is an exploded view of the present invention,

FIG. 2 is a longitudinal cross-sectional view of the present invention (i.e., a-A direction cross-sectional view in FIG. 1)

List of reference numerals: the touch screen comprises a glass-free infrared touch screen body 1, AG glass 2, a holographic projection film 3, a PDLC light-adjustable film 4, a one-way perspective film 5, super white glass 6, a power line 7 and a screen packaging piece 8.

Detailed Description

the invention will be further elucidated with reference to the drawings and the detailed description. It should be understood that the following detailed description is illustrative of the invention only and is not intended to limit the scope of the invention.

Example 1:

The utility model discloses transparent projection screen based on twice formation of image includes screen optical assembly, and screen optical assembly includes screen optical component, screen packaging part, does not have the infrared touch-sensitive screen of glass. With reference to fig. 1 and 2, the screen optical component of the adjustable transparent projection screen for augmented reality sequentially comprises AG glass 2, holographic projection film 3, PDLC light-adjustable film 4, one-way perspective film 5 and ultra-white glass 6 which are butted in a seamless and tiled mode from one side to the other side, wherein one side of the AG glass 2 faces the projector, when the adjustable transparent projection screen is used, the adjustable transparent projection screen projects on the projection screen from one side of the AG glass 2, primary imaging of a projected image is performed by using the holographic projection film 3, the projected image serves as a basic image, secondary imaging is performed on the PDLC light-adjustable film 4 by using the transmitted projected light again, and the secondary imaging is superposed on the primary imaging to enhance the imaging effect.

The PDLC light-tunable film 4 is connected to a power supply line 7, and a power supply regulator is provided on the power supply line 7. The PDLC tunable film 4 exhibits different haze and transparency according to different voltages and ac signals with corresponding duty ratios, when the voltage is 0 and the duty ratio is 0, the PDLC tunable film 4 exhibits the maximum haze and the opaque state, when the voltage and the duty ratio are a certain specific value, the minimum haze and the most transparent state and the transparency is about 88%, and the corresponding value in the middle corresponds to the corresponding haze and transparency, and conforms to the dimming curve. During in-service use, according to the use scene, when the tunable PDLC film 4 of needs is opaque, can not switch on the power, when the tunable PDLC film 4 of needs has certain transparency, through adjusting power regulator adjustment voltage and duty cycle, realize adjusting the transparency of the tunable PDLC film 4.

When the ambient light of the external real scene (namely one side of the ultra-white glass 6) is too bright, especially when the backlight (the light on one side of the ultra-white glass 6 is too bright), because the contrast between the imaging brightness of the projector and the light brightness of the real scene is reduced, namely the signal-to-noise ratio is reduced, the imaging quality of the projector seen by an observer is reduced (mainly the contrast of an image is reduced), a projected image becomes unclear, at the moment, the one-way perspective film 5 blocks the external light, the brightness of the external light is reduced, a relative 'dark environment' is formed, and the signal-to-noise ratio is improved; simultaneously, the accessible adjustment power regulator, change the haze of PDLC membrane of adjusting luminance 4 (be promptly through promoting membrane of adjusting luminance haze, reduce its light transmissivity, let more projection light secondary imaging on the membrane of adjusting luminance, membrane of adjusting luminance haze is big more, secondary imaging effect is better, primary imaging is on holographic projection membrane 3), strengthen the projection imaging effect, along with PDLC membrane of adjusting luminance 4's haze increases, can restrain the light of following the entering of ultrawhite glass one side, further promote the signal-to-noise ratio, strengthen the projection effect. The haze increase also causes the light transmittance and transparency of the PDLC tunable film 4 to be reduced, but the external real scene is enhanced by the ambient light, and the light flux passing through the optical component is still maintained at a high value, which has little influence on the external real scene viewed by the observer. Therefore, the influence of excessive backlight or ambient brightness is suppressed by adjusting the power supply regulator so that the transparency and the imaging effect are in an optimum state recognized by the observer (based on the difference in the visual perception of the image by each observer).

The utility model discloses there is not special requirement to the thickness of each layer optical assembly of projection screen, wherein figure 2 also only as the order of representing each layer to be not used for restricting the thickness relation between each layer, but for reaching the utility model discloses the purpose, there is the requirement to some specific parameters of each layer optical assembly of projection screen, for example AG glass 2's reflectivity is less than or equal to 4%, the luminousness of holographic projection membrane is more than or equal to 99%, PDLC tunable membrane 4's maximum luminousness is more than or equal to 88%, the biggest one-way luminousness of one-way perspective membrane 5 is more than or equal to 60%, the luminousness of super white glass 6 is more.

The existing projection screen performs diffuse reflection on light projected by a projector through screen surface materials (such as white paint, white cloth, superfine glass beads and the like) to directly form an image, and the process is called as primary imaging. The utility model discloses mainly used is observed to brighter environment from darker environment, will compromise formation of image effect and transparency, but is a pair of contradiction between the two. Because the utility model discloses the environment that uses is an open, environment light direction and intensity can constantly change (mainly watch from dark to light), and this and the general work of current projection screen have very big difference at a stable and very low dark ring border of environmental light and intensity. To solve these two problems, namely: 1. the problem of the compromise of imaging effect and transparency is solved, 2, the problem of the open environment that light direction and intensity can constantly change is adapted to, through analysis, selection of materials and design, the controllable secondary imaging technology of projection screen has been developed. The projector light (to maximize the projector brightness) passes through the AG glass 2, and after about 1% attenuation, is imaged on the holographic projection film 3, which is a one-time image. One physical property of the holographic projection film 3 is: 99% of light can pass through the imaging device while imaging, so that the problem of compatibility between imaging effect and transparency is solved. But additional physical properties of the holographic projection film 3 are: in bright light environment, the display quality will be reduced, the image will be gray, and in order to solve the new problem, a one-way perspective film 5 (also called a semi-reflective film) is added behind the holographic projection film 3 to create a relative 'dark environment' for the holographic projection film 3 to improve the primary imaging effect. In addition, the primary imaging effect of the holographic projection film 3 is solidified, and the holographic projection film cannot adapt to an open environment, and the light direction and the intensity can be changed constantly, so that the PDLC tunable film 4 is added after the holographic projection film 3 is attached, the projection light passing through the AG glass 2 and the holographic projection film 3 is imaged again on the PDLC tunable film 4, and the primary imaging effect of the holographic projection film 3 is enhanced after superposition. In order to give consideration to both the imaging effect and the transparency, when the ambient light is dark, the imaging effect can be ensured by one-time imaging, the PDLC light-adjustable film 4 is adjusted to be in a state of minimum haze and maximum transparency (the transparency is more than or equal to 88%), the light entering the real world of the eyes of an observer from one side of the ultra-white glass 6 is increased as much as possible, and the one-time imaging effect can be ensured; when ambient light is lighter, through the haze that increases PDLC membrane of adjusting luminance 4, reduce the transparency, let more projection light diffuse reflection on PDLC membrane of adjusting luminance 4, in order to improve secondary imaging's effect and stack on primary imaging, the transparency that reduces simultaneously, prevent more from the outside light that 6 one side of extra white glass got into to holographic projection membrane 3 on, increase "dark environment"'s darkness, further promote primary imaging's effect, let these material characteristics can exert and interact produces new effect, and the realization of the process of forming images once more on PDLC membrane of adjusting luminance 4, it is exactly the utility model discloses a core technology: the 'controllable secondary imaging technology of projection screen' solves the problem of adapting to open environment with constantly changing light direction and intensity.

When external environment light was darker, but PDLC membrane of adjusting luminance 4 transparency was transferred to the highest, did not influence the outdoor scene at the observation projection screen back, became bright when external environment light, when light intensity increased promptly, but adjust down PDLC membrane of adjusting luminance 4 transparency to a certain suitable value, restrain partial light, nevertheless guarantee to get into the light intensity of observer's eyes and keep being not less than the luminous intensity that gets into observer's eyes when ambient light was darker, still can guarantee to see through the effect that the real world outdoor scene was observed to the projection screen, this point is in the utility model discloses an it has been verified in the experiment.

implementation 2:

In order to increase the utility model discloses whole sensation effect when using installs screen packaging part 8 all around at all screen optical assembly, and screen packaging part 8 seals the encapsulation all around with screen optical component and no glass infrared touch screen.

Implementation 3:

In order to increase the utility model discloses human-computer interaction function when practical application, AG glass 2 is equipped with no glass infrared touch screen 1 towards a projector side. AG glass is equipped with no glass infrared touch screen towards a projector side, no glass infrared touch screen includes infra-red transmitter and infrared receiver, is provided with the infra-red transmitter that a plurality of rule was arranged at the top of AG glass one side and left side, and the opposite side sets up infrared receiver, and each infra-red transmitter all corresponds an infrared receiver. The infrared ray emitted by the infrared emitter is in an invisible light frequency band.

Example 4: practical application of the utility model

1. When the projection screen is applied to the scene of indoor weak light and outdoor strong light

(1) One side of AG glass of the projection screen faces the projector, one side of ultra-white glass faces outdoors, and an observer watches from the side of AG glass;

(2) Electrifying the screen optical assembly, and adjusting the PDLC light-adjustable film to the maximum transparent state;

(3) The light that the projecting apparatus throws is once forming an image at holographic projection membrane, and when super white glass one side external light was bright, adjust the display effect regulator, can adjust the light film of PDLC and transfer to certain haze, and the light that the projecting apparatus throws is at the light film secondary imaging of PDLC adjustable light, makes observation projection effect and perspective effect to the optimum.

(4) Along with the change of the direction and the intensity of the light, the display effect regulator is regulated to ensure that the projection effect and the perspective effect are observed to be in the best state.

2. when the projection screen of the patent is applied to the scene in the whole room

this scenario is typically used in a monitoring room, which works as (1), (2), (3) in the 1 st application. When the indoor room is in a low illumination level, one-time imaging can be basically ensured; when the indoor high-illumination room is used, the secondary imaging can be adjusted to achieve the best effect.

3. when the projection screen of the patent is applied as a scene of a common projection screen

(1) The positive operation mode: the AG glass side of the projection screen faces to the projector, the screen can be not electrified to work (or electrified to be adjusted to the maximum haze state), at the moment, the PDLC light-adjustable film is in an opaque state, an observer watches from the AG glass side, the observed image is a superposed image formed by primary imaging and secondary imaging, and the image is stronger than the image only formed by the holographic projection film, so that the observer can watch under the indoor high-illumination condition, and the phenomenon can not be realized by only using the holographic projection film for primary imaging;

(2) the back projection working mode is as follows: the AG glass side of the projection screen faces the projector, and is arranged in a rear projection mode, the screen can work without electricity (or can be electrified and adjusted to the maximum haze state), at the moment, the PDLC light-adjustable film is in an opaque state, an observer watches from the side of the super white glass, and the image formed by secondary imaging of the image is watched, and in the working mode, the required ambient illumination is low.

The technical means disclosed by the scheme of the utility model is not limited to the technical means disclosed by the technical means, but also comprises the technical scheme formed by the arbitrary combination of the technical characteristics.

In light of the foregoing, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims (4)

1. A transparent projection screen based on twice imaging is characterized by comprising a screen optical assembly, wherein the screen optical assembly comprises a screen optical component, a screen packaging piece and a glass-free infrared touch screen, the screen optical component sequentially comprises seamless AG glass, a holographic projection film, a PDLC (polymer dispersed liquid crystal) light-adjustable film, a one-way perspective film and ultra-white glass from one side of the screen optical component facing a projector to the opposite side of the screen optical component, the holographic projection film is used for carrying out primary imaging on a projected image, the primary imaging is used as a basic image, the transmitted projected light is used for carrying out secondary imaging on the PDLC light-adjustable film again, and the secondary imaging is superposed on the primary imaging to enhance the imaging effect;

The glass-free infrared touch screen is arranged on the surface of one side, facing the projector, of the AG glass;

The screen packaging piece is packaged around the screen optical component and the glass-free infrared touch screen, and the screen optical component and the glass-free infrared touch screen are sealed and packaged around the screen optical component and the glass-free infrared touch screen.

2. The transparent projection screen based on two-pass imaging as claimed in claim 1, wherein the reflectivity of AG glass is less than or equal to 4%, the light transmittance of holographic projection film is greater than or equal to 99%, the maximum light transmittance of PDLC tunable film is greater than or equal to 88%, the maximum one-way light transmittance of one-way perspective film is greater than or equal to 60%, the light transmittance of ultra-white glass is greater than or equal to 92%, and the total light transmittance of augmented reality tunable transparent projection screen is greater than or equal to 47%.

3. The double-imaging-based transparent projection screen of claim 1, wherein the glass-free infrared touch screen comprises infrared emitters and infrared receivers, a plurality of regularly arranged infrared emitters are arranged on the top and the left side of one side of the AG glass, the infrared receivers are arranged on the opposite side of the AG glass, each infrared emitter corresponds to one infrared receiver, and infrared rays emitted by the infrared emitters are in an invisible light band.

4. the double-imaging based transparent projection screen of claim 1, wherein the PDLC dimmable film is connected to a power line, and a power regulator is disposed on the power line.