JPH09130704A - Head mounted video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a video image with high image quality even when a signal having even numbered fields and odd numbered fields alternately in an existing software by providing an inter-field interpolation circuit. SOLUTION: A 2-dimension video signal sent from a reproduction device via a cord 16 is received and distributed into a synchronization separator circuit 21 and an inter-field interpolation circuit 22. The synchronization separator circuit 21 separates only synchronizing signals from the video signal and gives them to a timing generator 20. The inter-field interpolation circuit 22 receiving the clock signal generated by the timing generator 20 applies inter-field interpolation processing to the received 2-dimensional video signal and sends the result to an LCD 2(R, L). The scanning line of the 2-dimensional video signal is interpolated by the inter-field interpolation and the picture element arrays in the longitudinal direction of the LCD 2 are used for video image without waste, than the video image with high image quality is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-mounted image display device having left and right image display elements corresponding to the left and right eyes of an observer.

[0002]

2. Description of the Related Art Generally, a TV image is shown in FIG.
As shown in, the image is displayed by the scanning lines (solid line 103, alternate long and short dash line 104) of the screen 102 of the television 101. The signal at this time is an odd field 10 as shown in FIG.
5 and the even field 106 are alternately written (105 ', 106', 105 ", 106" ...).

This is a head-mounted image display device (hereinafter referred to as HM
In the case of diverting to D), if this signal is simultaneously sent to each of the left and right image display elements such as an LCD or a CRT display, left and right images can be observed in the same phase. By the way, the HMD includes an HMD for observing a two-dimensional image such as a movie or a television image for observing a two-dimensional image, and an HMD for observing a three-dimensional image for observing a three-dimensional image such as virtual reality.

Therefore, in the case of a three-dimensional HMD, different images including parallax are displayed as left and right images.
Generally, field-sequential signal processing is performed, for example, odd-numbered fields (105, 105 ', 105 "...)
Signal of the even field (10
6, 106 ', 106 "...) are formed so as to be distributed to the image display element for the left eye. This structure is disclosed in JP-A-5-103349 and JP-A-5-3.
It is disclosed in Japanese Patent Publication No. 00544.

[0005]

Here, a television for general household use is viewed from a position separated by a certain distance, and even if the resolution is sacrificed to some extent, it is not considered to be a problem. The 525 scanning lines are divided into an odd field and an even field for display. On the other hand, in the HMD in which the device body is mounted on the observer's head and the image display element is arranged near the observer's eye,
Since there is always a demand for realistic images, higher image quality is desired.

However, even if this is the case, if the image medium used for the HMD has to be taken by a high-quality camera or the like different from other objects, not only the cost will increase, but also the market will increase. It becomes impossible to use existing software such as existing video that is circulated, and the usage of the viewer is narrowed, which may hinder commercial development in the HMD field.

Further, in the three-dimensional HMD, since the odd field and the even field are distributed to the left and right, only one of the vertical scanning lines is displayed at any time, and the vertical scanning line of the image display element is used for high image quality. The effect is reduced to half even if the direction pixel row having one frame is used. Therefore, the present invention includes an HM including a signal processing circuit that allows a user to enjoy a high-quality image even when using a signal having an even field and an odd field that are present in existing software.
The purpose is to realize D.

[0008]

In order to achieve the above object, in the HMD of the present invention, a video signal is sent to the right-eye video display element, the left-eye video display element, and the left and right video display elements. A signal processing circuit, an eyepiece for the right eye for guiding the image of the right-eye image display element to the observer's right eye, and a left eye for guiding the image of the left-eye image display element to the observer's left eye Eyepiece lens, and the signal processing circuit is formed as a circuit for two-dimensional video display that sends video signals equal to the left and right video display elements, and the signal processing circuit has an inter-field interpolation circuit. However, it is characterized in that the inter-field interpolation circuit is provided so as to operate when a signal is sent to the left and right video display elements.

With such a configuration, the HMD of the present invention can realize high image quality because the signals subjected to inter-field interpolation processing of the two-dimensional video signal are displayed on the left and right video display elements. That is, as shown in FIG. 1, among video signals in which odd fields (105, 105 ', 105 "...) And even fields (106, 106', 106" ... A signal for one scanning line (in the range of IH indicated by an arrow) (107 for an odd field)
a, 107b, 107c, 107d ... And the even fields are 108a, 108b, 108c, 108d ...
... ) Are alternately rearranged and sent to the image display element as inter-field interpolated signals 109, 109 '.... Therefore, before inter-field interpolation, one screen (for example, 1/60 seconds) could display only the scan lines corresponding to either odd or even field signals, but after inter-field interpolation, like field 109, 107a, 108
a, 107b, 108b, 107c, 108c, 107
d, 108d ...
Images with double scanning lines can be displayed.

Therefore, each screen to be displayed is not decimated with an odd field or an even field as in the conventional case, and an image is displayed by using all the pixels on the image display element, so that the image quality can be improved. Of. Next, in another HMD of the present invention, a right-eye image display element, a left-eye image display element, a signal processing circuit that sends an image signal to the left and right image display elements, and the right-eye image display. Head-mounted image having an eyepiece for the right eye for guiding the image of the element to the right eye of the observer, and an eyepiece for the left eye for guiding the image of the image display element for the left eye to the left eye of the observer A display device, the signal processing circuit is formed as a field-sequential signal processing circuit for displaying a three-dimensional image on the left and right image display elements, the signal processing circuit has an intra-field interpolation circuit, It is characterized in that it is provided at a position where the intra-field interpolation circuit operates when a signal is sent to the left and right image display elements.

According to another HMD of the present invention, since the signal obtained by performing the intra-field interpolation processing of the three-dimensional video signal is displayed on the left and right video display elements by such a configuration, high quality can be realized. That is, when the three-dimensional video signal is displayed by the field sequential method, the odd field and the even field are images from different fields of view including parallax. For this reason, inter-field interpolation as in the case of a two-dimensional video signal causes not only high image quality but also deterioration of image quality. Therefore, for the 3D video signal by the field sequential method, the intra-field interpolation processing is performed. According to this processing, for example, in the case of the signal of the odd field 105 as shown in FIG. 2, the signals (107a, 107b, 107c, 107d ...
,) Are double-written and the inter-field interpolated signal 110 (107a, 107a, 107b, 1) is written.
07b, 107c, 107c, 107d, 107d ...
…). The field signals 106 and 10
5 ', 106' ..., In the same way, the signals 111, 110 ', 111' ... Are interpolated in the field. Then, this is applied to the odd field signals 110 and 110 '.
.. and even field signals 111, 111 '.. are distributed to the left and right image display elements.

Therefore, as in the case of the two-dimensional video signal, all the pixels of the video display element are used in each screen, so that the image quality can be improved as compared with the conventional one. Further, in another HMD of the present invention, a right-eye image display element, a left-eye image display element, a signal processing circuit that sends an image signal to the left and right image display elements, and the right-eye image display element. Head-mounted image display having an eyepiece for the right eye for guiding the image of the right eye to the observer's right eye, and an eyepiece for the left eye for guiding the image of the image display element for the left eye to the left eye of the observer A determination circuit for determining whether the video signal itself is a two-dimensional video signal or a three-dimensional video signal, an inter-field interpolation circuit, an intra-field interpolation circuit, and the field determination circuit. Switch means for operating the inter-field interpolation circuit when it is determined to be a two-dimensional video signal and for operating the intra-field interpolation circuit when the field determination circuit determines to be a three-dimensional video signal. It is.

The HMD of the present invention having such a structure enables high-quality video display for both two-dimensional video signals and three-dimensional video signals. That is, normally, the two-dimensional HMD and the three-dimensional HMD are separately used,
It is troublesome and does not meet general needs. Therefore, an HMD capable of observing both two dimensions and three dimensions with one HMD is desired. However, as described above, there is a difference in the interpolation method between the two-dimensional case and the three-dimensional case. It may be considered to perform signal processing by unifying this in both two-dimensional and three-dimensional inter-field interpolation, but in this case, although the image quality of the two-dimensional video signal is improved as compared with the conventional HMD, it is compared with inter-field interpolation. I have to say that it is inferior.

Therefore, the present invention is provided with a judging circuit for judging whether the signal sent to the signal processing circuit is a two-dimensional image signal or a three-dimensional image signal, and based on the signal from this circuit, By switching between inter-field interpolation circuit and intra-field interpolation circuit,
It is possible to improve the image quality most effectively in both 2D and 3D.

Further, another HMD of the present invention is a video display element for the right eye, a video display element for the left eye, a signal processing circuit for sending a video signal to the left and right video display elements, and the video for the right eye. Head-mounted type having an eyepiece for the right eye for guiding the image of the display element to the right eye of the observer, and an eyepiece for the left eye for guiding the image of the image display element for the left eye to the left eye of the observer An image display device, and the signal processing circuit, inter-field interpolating circuit, switch means for arbitrarily switching between the operation of the intra-field interpolating circuit and the inter-field interpolating circuit and the operation of the intra-field interpolating circuit; It is characterized by having.

With the HMD of the present invention, with the above-described configuration, the same switching as described above can be performed, and in some cases, even in the same two-dimensional image, intra-field interpolation may be desired. Therefore, by allowing the user to arbitrarily switch,
The user himself can make the image quality selection.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. First, 1 of HMD of the present invention
The overall structure of the example is shown in FIGS. As shown in FIG. 4, the display device main body 1 includes a liquid crystal display element (hereinafter, LCD) 2
And an eyepiece optical system 4 for guiding the light from the LCD to the observer's eyeball 3. A prism 5 made of a medium having the same refractive index may be bonded to the eyepiece optical system 4 so that both surfaces sandwiching the bonded surface have substantially the same curvature (FIG. 4B). In this case, the external light 6 can reach the observer's eyeball 3 without being distorted. Further, when it is desired to block external light, a liquid crystal shutter 7 may be provided between the external world and the prism 5. When the two liquid crystal shutters are stacked, the light blocking rate is further increased. Further, the eyepiece optical system 4 may have a prism shape having a backside reflecting mirror 9 with the half mirror surface 8 interposed therebetween. The main body 1 is provided with temporal frames 10 as shown in the left and right in succession, and the temporal frames 10 on both sides are provided.
Are connected by a parietal frame 11. Further, a rear frame 13 is provided in the middle of the temporal frames 10 on both sides via a leaf spring 12, and the rear frame 13 is applied to the rear parts of both ears of the observer, and the parietal frame 11 is placed on the observer. By mounting it on the top of the head, the display device body 1 can be held in front of the observer's eyes. A crown pad 14 made of an elastic material such as a cancellous body is attached to the inside of the crown frame 11. Similarly, a similar pad is attached to the inside of the rear frame 13,
The user does not feel uncomfortable when the display device is worn on the head.

The rear frame 13 has a speaker 1
5 is attached so that stereophonic sound can be heard while observing images. Speaker 1 like this
Since a reproducing apparatus 17 such as a portable video cassette is connected to the main body 1 having 5 through a video / audio transmission cord 16, an observer can freely reproduce the reproducing apparatus 17 at a belt portion or the like as shown in the drawing. It can be held in its position and enjoy video and audio. Reference numeral 18 shown in the figure is a control unit for the switches and volume of the reproducing apparatus 17. The playback device 17 may be a device that receives an electric wave from the outside, or a device that receives a TV or a computer signal.

Inside the crown frame 11, various electronic parts such as a video signal processing circuit and an audio signal processing circuit are built. Hereinafter, various embodiments of the video signal processing circuit of the present invention will be shown. (First Embodiment) First, FIG. 5 shows a block diagram of a video signal processing circuit for processing a two-dimensional video signal from a reproducing apparatus 17 as a first embodiment. 2R and 2L are display drawings of the left and right LCDs, and 19R and 19L are LCDs 2R and 2
An LCD driver corresponding to L, 20 is a timing generator, 21 is a sync separation circuit, and 22 is an inter-field interpolation circuit. From this configuration, the regeneration device 17 to the code 1
The two-dimensional video signal transmitted through 6 is branched to the sync separation circuit 21 and the inter-field interpolation circuit 22. The sync separation circuit 21 separates only the sync signal from the video signal and inputs the sync signal to the timing generator 20. Then, in the timing generator 20, the inter-field interpolation circuit 22 and the LCD driver 19
It issues a clock signal for driving (R, L).
Inter-field interpolation circuit 22 which receives this clock signal
Performs inter-field interpolation processing on the input 2D video signal and transmits it to the LCD 2 (R, L). The clock signal is also input to the LCD driver 19 (R, L) at the same time, a timing signal for display is sent to the LCD 2 (R, L), and an image is displayed.

As described above, in the first embodiment, the scanning lines are interpolated by the inter-field interpolation of the two-dimensional video signal, and the vertical pixel rows of the LCD 2 are used for video display without waste. It is possible to display high quality images. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. For the sake of simplicity, the same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

First, FIG. 6 is a block diagram of a video signal processing circuit for processing a three-dimensional video signal. Here, 23 is an intra-field interpolation circuit, and 24 is a field determination circuit. With this configuration, the 3D video signal transmitted from the reproducing device 17 through the code 16 is branched to the sync separation circuit 21 and the intra-field interpolation circuit 23. The signal sent to the internal sync separation circuit 21 issues a clock signal for driving the intra-field interpolation circuit 23 and the LCD driver 19 (R, L) from the timing generator 20 as in the first embodiment. The timing generator 20 also separately outputs a clock signal to the field determination circuit 24, and the field determination circuit 24 controls the LCD driver 19 (R, L) in response to the timing. Specifically, this control is based on the field sequential system, and the left and right LCDs 2 are controlled so that a video signal including parallax between the odd field and the even field is not guided to both eyes of the observer in advance. They are operated alternately according to the corresponding field signal. For example, if the odd field signal is for the left eye and the even field signal is for the right eye, the odd field signal is L
When sent to CD2 (L, R), LCD2L controls the display state and LCD2R does not display. When even field signal is sent to LCD2 (L, R), LCD2L displays. LCD2
R controls the display state.

Further, by the intra-field interpolation circuit 23,
The scanning lines are interpolated for each field unit without intermixing even fields and odd fields.
The video is supplied to 2. As described above, according to the second embodiment, it is possible to display a 3D video signal with high image quality by intra-field interpolation. (Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram of a circuit for automatically dividing and interpolating a 2D video signal and a 3D video signal according to their characteristics. Here, 25 is a 2D / 3D determination circuit for discriminating between a 2D video signal (2D) and a 3D video signal (3D), and 26 switches between an intra-field interpolation circuit and an inter-field interpolation circuit. It is a switch.

With this configuration, the playback device 17 outputs the code 1
A two-dimensional video signal or a three-dimensional video signal is sent through 6. This signal is supplied to the sync separation circuit 21, 2D / 3.
It is sent to the D determination circuit 25, the inter-field interpolation circuit 22, and the intra-field interpolation circuit 23. The 2D / 3D determining circuit 25 interpolates the signal interpolated by the inter-field interpolating circuit 22 when the video signal is a two-dimensional image, and interpolates the intra-field interpolating circuit 23 when the video signal is a three-dimensional image. The switch 26 is controlled so that a signal can be sent to the LCD 2 (L, R). A signal is also sent from the 2D / 3D determination circuit to the field determination circuit 24. In the case of a two-dimensional image, control of the LCD driver 19 is entrusted to the clock signal from the timing generator 20, and in the case of a three-dimensional image signal. Is ON / OF of the left and right LCDs 2 corresponding to odd and even fields
By controlling F, the left and right images are adjusted to be displayed alternately to create a stereoscopic image.

As described above, in the third embodiment, it is possible to automatically discriminate inter-field interpolation for a two-dimensional video signal and intra-field interpolation for a three-dimensional video signal for processing. A high-quality image can be obtained regardless of the type of image signal. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 shows a modified example of the third embodiment, in which the structure of the switch 26 is of a type in which the observer manually switches from the outside as shown in FIG.
A D / 3D circuit switching button 27 is provided. The delay button 27 may be provided on the HMD main body 1.

With respect to the configuration, the circuit arrangement is different, but the operation of each circuit is the same as that of the third embodiment. According to the configuration of the fourth embodiment, the observer can manually switch between two-dimensional and three-dimensional, so that the cost can be reduced because there is no extra circuit switch. In addition, even in the case of two-dimensional video, the desire that intra-field interpolation is better than inter-field interpolation can be answered, and user-driven interpolation processing can be performed.

The configuration of the field determination circuit 24 shown in each embodiment will be described with reference to FIG. The field determination circuit determines whether the video signal is of an odd field or an even field and sends a signal, and an inverter 29 for inverting the signal.
A NAND 30L for sending a signal to the LCD driver 19L for the left eye to control, a NAND 30R for the right eye, and a switch 31 for sending a signal to the NAND 30 (L, R) corresponding to the switch 26 are arranged.

When the switch 31 is ON, N
AND30 outputs the signal of "H", and switch 31 turns O.
In the case of FF, the NAND 30 becomes an inverting circuit. Also,
It is assumed that the LCD 2 is displayed when the "H" signal is sent from the NAND 30 to the LCD drive 19, and the LCD 2 is not displayed when the "L" signal is sent. With this configuration, for example, in the field detection circuit 28, it is assumed that the odd field signal is transmitted as "H" and the even field signal is transmitted as "L", and "H" and "L" are mutually inverted.
Then, it is assumed that an image for the left eye is sent to the odd field and an image for the right eye is stereoscopically included in the even field with parallax, respectively, from the reproducing device 17. Then, the switch 26 determines that it is a three-dimensional image and connects it to the intra-field interpolation circuit 23. In conjunction with the operation of the switch 26, the switch 31 turns off the switch. Therefore, in the case of three-dimensional video, the signal input to the NAND 30 is only the signal that has passed through the field detection circuit.

First, in the case of an odd field signal, the signal is output as "H", inverted by the inverter 29 to become "L", and then inverted again by the NAND 30L and returned to "H". Further, since a signal directly reaches the NAND 30R from the field detection circuit 28, the output "H" signal is the NAND 30R.
Inverted to "L" at R. Therefore, in this case, only the left eye is displayed. Next, in the case of the even field signal, the output signal is "L", so that when viewed in the same way as in the case of the odd field, only the right eye is displayed.

When a 2D video signal is input, the switch 26 is connected to the inter-field interpolation circuit,
In conjunction with this, the switch 31 is turned on. NA
The "H" signal is always output from the ND 30 (R, L), and only the "H" signal is input to the LCD driver.
Therefore, the left and right LCDs 2 are always displayed. By the way, the field determination circuit is premised on the presence of the switch 31. However, when the field determination circuit is used for a circuit dedicated to 3D video signal processing as in the second embodiment, 2D / 3D.
The signal from the determination circuit 25 replaces the switch 31.

Further, the present invention is not limited to the above-mentioned embodiment, and the circuit arrangement may be changed or a circuit having the same function may be replaced.

[0031]

As is apparent from the above description, according to the HMD of the present invention, it is possible to perform an appropriate interpolation process for each of a two-dimensional video signal and a three-dimensional video signal, and to observe a high quality image. .

[Brief description of the drawings]

FIG. 1 is a principle diagram illustrating inter-field interpolation processing.

FIG. 2 is a principle diagram illustrating intra-field interpolation processing.

FIG. 3 is an overall perspective view of HMD mounting.

FIG. 4 is a sectional view of an optical system in the main body of the HMD.

FIG. 5 is a block diagram showing a first embodiment of the present invention.

FIG. 6 is a block diagram showing a second embodiment of the present invention.

FIG. 7 is a block diagram showing a third embodiment of the present invention.

FIG. 8 is a block diagram showing a fourth embodiment of the present invention.

FIG. 9 is a diagram showing an external button for 2D / 3D switching.

FIG. 10 is a block diagram of a field determination circuit.

FIG. 11 is a diagram illustrating a scanning method of a television.

FIG. 12 is a diagram illustrating a field-sequential video signal.

[Explanation of symbols]

 1 Display Device Main Body 2 Liquid Crystal Display Element 3 Observer Eye 4 Eyepiece Optical System 5 Prism 6 External Light 7 Liquid Crystal Shutter 8 Half Mirror Surface 9 Rear Mirror 10 Temporal Frame 11 Top Frame 12 Leaf Spring 13 Rear Frame 14 Top Pad 15 Speaker 16 video / audio transmission code 17 playback device 18 volume control section 19R, 19L LCD driver 20 timing generator 21 sync separation circuit 22 inter-field interpolation circuit 23 intra-field interpolation circuit 24 field determination circuit 25 2D / 3D determination circuit 26 switch 27 2D / 3D circuit switching button 28 field detection circuit 29 inverter 30 NAND 31 switch

Claims (4)

[Claims] 1. A right-eye image display element, a left-eye image display element, a signal processing circuit for transmitting an image signal to the left and right image display elements, and an image on the right-eye image display element on the right side of an observer. A head-mounted image display device having a right-eye eyepiece for guiding to an eyeball, and a left-eye eyepiece for guiding an image of the left-eye image display element to an observer's left eyeball, wherein the signal processing The circuit is formed as a circuit for two-dimensional video display that sends video signals equal to the left and right video display elements,
Further, the signal processing circuit has an inter-field interpolation circuit, and is provided so that the inter-field interpolation circuit operates when sending a signal to the left and right video display elements. Display device. 2. A right-eye image display element, a left-eye image display element, a signal processing circuit for sending an image signal to the left and right image display elements, and an image on the right-eye image display element on the right side of an observer. A head-mounted image display device having a right-eye eyepiece for guiding to an eyeball, and a left-eye eyepiece for guiding an image of the left-eye image display element to an observer's left eyeball, wherein the signal processing The circuit is formed as a field-sequential signal processing circuit for displaying a three-dimensional image on the left and right video display elements, and the signal processing circuit has an intra-field interpolating circuit to output a signal to the left and right video display elements. A head-mounted image display device, characterized in that it is provided at a position where the intra-field interpolation circuit operates during sending. 3. A right-eye image display element, a left-eye image display element, a signal processing circuit for sending an image signal to the left and right image display elements, and an image on the right-eye image display element on the right side of an observer. A head-mounted image display device having a right-eye eyepiece for guiding to an eyeball, and a left-eye eyepiece for guiding an image of the left-eye image display element to an observer's left eyeball, wherein the signal processing When the circuit determines that the video signal itself is a two-dimensional video signal or a three-dimensional video signal, an inter-field interpolating circuit, an intra-field interpolating circuit, and the field determining circuit determines that the video signal is a two-dimensional video signal. And a switch means for operating the inter-field interpolation circuit and operating the intra-field interpolation circuit when the field determination circuit determines that the field determination circuit is a three-dimensional video signal. 4. A right-eye image display element, a left-eye image display element, a signal processing circuit for sending an image signal to the left and right image display elements, and an image on the right-eye image display element on the right side of an observer. A head-mounted image display device having a right-eye eyepiece for guiding to an eyeball, and a left-eye eyepiece for guiding an image of the left-eye image display element to an observer's left eyeball, wherein the signal processing A circuit includes an inter-field interpolating circuit, an intra-field interpolating circuit, and switch means for arbitrarily switching between the operation of the inter-field interpolating circuit and the operation of the intra-field interpolating circuit. Wearable video display device.