JP5157342B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device such as a liquid crystal display device, a driving method thereof, and an electronic apparatus.

  2. Description of the Related Art Conventionally, an electro-optical device such as a liquid crystal display device that displays different images in two different display ranges (hereinafter sometimes referred to as “two-image display device”) has been proposed. According to this two-image display device, each of viewers located in different directions around the device can view images of different contents. Therefore, the apparatus is suitable, for example, by being incorporated in the center of an automobile dashboard. According to this, for example, the driver displays an image having contents relating to route information, traffic jam information, etc., and a person other than the driver such as a person sitting in the passenger seat (hereinafter referred to as “passenger”). In other words, an image having the contents of a movie or the like reproduced from a DVD or the like can be displayed.

As such a two-image display device, for example, a device disclosed in Patent Document 1 is known. In particular, in the “display device” in Patent Document 1, it has been proposed to increase the passenger's image display time with respect to the entire image display time in the device (for example, [Claim 3] FIG. 13] etc., especially [0122] [0123]). As described above, this corresponds to the fact that the image content seen by the driver is different from that seen by the passenger. That is, “the driver does not stare at the display while the vehicle is driving”, but “the passenger in the passenger seat is considered to watch the DVD reproduction output” (see Patent Document 1 above). [Excerpt from [0123]).
JP 2006-301573 A

  By the way, it is generally known that a phenomenon called so-called moving image blur or tailing occurs in an electro-optical device such as a liquid crystal display device. This is a so-called hold-type display in which an image is displayed by a liquid crystal display device or the like maintaining display light for a certain period, and this form causes a kind of incompatibility with human visual characteristics. (For this point, for example, Yashiro Kurita, “Principal video quality degradation caused by liquid crystal display and its improvement method, etc.”, IEICE Technical Report, EID2000-47, pp.13- 18 (2000-09) etc.).

  In order to suppress such blurring of moving images, for example, it has been proposed to perform intermittent display or increase the frame rate. The former “intermittent display” means that the display light is not held over the entire original display period, but is displayed while light is shielded within a certain period of time. On the other hand, the latter aims at shortening the display period itself. In any case, it can be said that these methods prevent display light from entering the eyes of the viewer for a relatively long period of time. In fact, in the former intermittent display method, it is generally reported that blurring is suppressed when the duty ratio (here, the ratio of the light emission time per repetition cycle) is reduced (for example, about this point, See Hiroshi Ito et al., “Examination of video image quality improvement method for AMLCD”, ITE Technical Report Vol.28, No.22, pp.13-16 (BCT2004-69 (Mar.2004)). Literature ").

  However, when the moving image blur suppression method as described above is adopted, another problem arises on the other hand. That is, the risk of flickering increases. In particular, it has been reported that the intermittent display method described above is able to eliminate moving image blur by lowering the duty ratio, but on the other hand, the influence of flicker increases. (See references above). That is, both are in a trade-off relationship with respect to the duty ratio.

Incidentally, such a flicker is highly likely to be felt strongly by the driver when a two-image display device mounted on a vehicle is assumed. This is due to the following circumstances.
That is, first, on human visual characteristics, first, flicker is more easily recognized when viewing an image while moving the line of sight than when viewing an image while fixing the line of sight, Secondly, it is known that flicker is easily recognized at 10 to 20 degrees around the center of the visual field. And, the driver usually stares at the traveling direction of the car, and the display device often gives a glimpse of the image of the display device in a timely manner (that is, the driver moves the line of sight, Moreover, images are often captured at the edge of the field of view.) In the end, flicker is more likely to be felt by the driver.

From the above viewpoint, the above-mentioned Patent Document 1 has some problems. This is because, in this document, as described above, it has been proposed to relatively increase the image display time for passengers. However, in this case, the time during which the display light is held is increased accordingly. This is because the above-mentioned motion blur problem may occur from the front. Patent Document 1 does not describe anything about such problem awareness.
Further, in a two-image display device, displaying an image in two display ranges by switching a shutter or the like is nothing but the fact that the intermittent display described above can be considered in terms of one display range. However, in this case, if the image display time on the passenger side is relatively long as in Patent Document 1, naturally, the image display time on the driver side is relatively short. In other words, since the duty ratio is lowered, a situation in which flicker is more easily recognized is created.

  The present invention has been made in view of the above-described circumstances, and in the case where separate images are displayed in two display ranges with one device, it is possible to suppress the occurrence of moving image blur and flicker in the image, It is an object of the present invention to provide an electro-optical device capable of displaying a higher-quality image, a driving method thereof, and an electronic apparatus.

  In order to solve the above-described problem, an electro-optical device according to the present invention includes an electro-optical element that receives a supply of an image signal and changes a light emission mode or a light transmission mode, and includes a first display range and a second display range. An electro-optical device capable of displaying images having different contents in each of the light source and the display light generated from the light source in the first direction or the second display range corresponding to the first display range. In the case where the light direction determining means for proceeding in the corresponding second direction, and displaying a still image in the first display range and a moving image in the second display range, within one frame period having a predetermined length, The light source and the light direction determining means are arranged such that the length of the first period in which the display light is advanced in the first direction is equal to or longer than the length of the second period in which the display light is advanced in the second direction. Luminescence period controlling at least one And a control means.

According to the present invention, when a still image is displayed in the first display range and a moving image is displayed in the second display range, the display light projection time in the first direction corresponding to the former, that is, the length of the first period. Is longer than the time of projection of the display light in the second direction corresponding to the latter, that is, the length of the second period.
From this, first, the occurrence of motion blur in the moving image in the second display range is suppressed as much as possible. For if the length of the first period is larger than that of the second period, conversely, if the length of the second period is smaller than that of the first period, This is because the duty ratio defined in (1) becomes low.
Further, according to the present invention, the occurrence of flicker in the still image in the first display range is suppressed as much as possible. This is because the length of the first period is longer than that of the second period.
In addition, when the first display range and the second display range are mixed with each other, there may be a so-called mixed display range, but the first display range and the second display range in the claims are the mixed display. Except for the range, it means a range in which different images are displayed in the first display range and the second display range.

In the electro-optical device according to the aspect of the invention, the light emission period control unit may be configured to control the length of the first and second periods by turning on or off the light source.
According to this aspect, since the length of the first and second periods is controlled by a more direct method of turning on or off the light source, for example, only the traveling direction of the display light is controlled with the light source on. As compared with the case where the length is controlled by a method such as the above, it is possible to reduce power consumption, and it is possible to prevent the light source from being consumed more than necessary.

In the electro-optical device according to the aspect of the invention, the light direction determination unit may pass a part of the light emitted from the light source in the first region and block the rest of the light in the second region. And a shutter means capable of blocking a part of the light emitted from the light source in the first region and transitioning between a state in which the rest of the light is allowed to pass in the second region, The light passing through the first region in the shutter means travels in the first direction, and the light that passes through the second region in the shutter means travels in the second direction. And a lens unit that refracts light.
According to this aspect, the traveling direction of the display light is suitably determined.

In this aspect, the shutter unit may include a liquid crystal element, and may be configured to allow the light to pass or shield depending on the alignment state of the liquid crystal constituting the liquid crystal element.
According to this, light can be passed and shielded better. Therefore, determination of the traveling direction of the display light described above can also be performed more suitably.
In addition, since the shutter means can be configured substantially in the same manner as a general liquid crystal display device, in that case, there is also an advantage that the control becomes relatively easy.
Further, from this point of view, if the “electro-optical device” according to the present invention is applied to a liquid crystal display device, the liquid crystal display device and the shutter means can basically have the same configuration. Therefore, the common elements of these control circuits can be combined into one configuration, or their response performances can be made substantially the same, so that the entire apparatus can be controlled stably. Various advantages such as being able to be obtained can be obtained.

In the electro-optical device according to the aspect of the invention, the light emission period control unit includes an image signal supply control unit that controls a supply timing of the image signal to the electro-optical element, and the image signal supply control unit includes the one frame. Within the period, the first supply timing of the image signal for displaying the image for the first display range to the electro-optic element, and the image signal for displaying the image for the second display range, The supply timing is controlled so that the time between the second supply timing to the electro-optic element is longer than the remaining time in the one frame period, and the light emission period control means includes The first period may be set within the first and second supply timings, and the second period may be set within the remaining time.
According to this aspect, the lengths of the first and second periods are suitably controlled through suitably controlling the supply timing of the image signals for displaying the respective images for the first and second display ranges. The
More specifically, if the first and second supply timings described above are visited once each within one frame period, the supply timing of the image signal of the first display range image (first The time from one supply timing) to that for the second display range (second supply timing) is the time from the second supply timing to the first supply timing in the next frame (the “remaining time”). Corresponding to an example), the length of the first period becomes larger than that of the second period. Therefore, the above-described operational effects according to the present invention are exhibited.

In the electro-optical device according to the aspect of the invention, the light emission period control unit may include a majority of (2n + 1) (n is a positive integer) small frame periods that divide the one frame period by the same length. The first period may be set to correspond to the small frame period, and the second period may be set to correspond to the remaining small frame period.
According to this aspect, the period occupied by the majority of the odd number of small frame periods corresponds to the “first period”, and the rest corresponds to the “second period”. Thereby, the length of the first period is longer than that of the second period. Therefore, the effects according to the present invention described above are exhibited.
Further, in this aspect, since more light emission periods are set within one frame period, relatively high-speed switching is performed, and the frame rate is substantially increased. Therefore, according to this aspect, the flicker reduction effect in the image for the first display range can be enjoyed more effectively. Moreover, the effect of reducing the motion blur in the image for the second display range can be enjoyed more effectively.

In the electro-optical device according to the aspect of the invention, the light emission period control unit may include half of the small frame periods among 2n (n is a positive integer) small frame periods that divide the one frame period by the same length. The first period may be set so as to correspond to the frame period, and the second period may be set so as to correspond to the remaining small frame period.
According to this aspect, half of the even number of small frame periods are allocated to the “first period” and the “second period”, respectively. As a result, the lengths of the first and second periods are the same, but since a larger number of light emission periods are set within one frame period, relatively high-speed switching is performed. In practice, the frame rate increases. Therefore, according to this aspect, the flicker reduction effect in the image for the first display range can be enjoyed more effectively. Moreover, the effect of reducing the motion blur in the image for the second display range can be enjoyed more effectively.

In an aspect in which the one frame period is divided into a plurality of small frame periods, the first period includes a plurality of first small periods each having a length corresponding to the length of the small frame period. The two periods are composed of a plurality of second small periods each having a length corresponding to the length of the small frame period, and the first and second small periods are alternately repeated within the one frame period. You may comprise as follows.
According to this aspect, the “first period” and the “second period” are not considered as periods of continuous time, respectively. In the state where the first and second sub-periods are alternately repeated in order from the beginning of one frame period, such as the first sub-period, the second sub-period, the first sub-period, the second sub-period,. The entire period corresponding to the first small period corresponds to the “first period”, and the entire period corresponding to the second small period corresponds to the “second period”.
In any case, according to such an aspect, the frame rate is substantially increased, so that the above-described effect can be more effectively enjoyed.

In order to solve the above-described problems, an electronic apparatus according to the present invention includes the electro-optical device according to various aspects described above.
Since the electronic apparatus of the present invention includes the various electro-optical devices described above, occurrence of moving image blur is suppressed as much as possible in the moving image for the second display range, and flicker is generated in the still image for the first display range. It is possible to display a high-quality image in which the occurrence of is suppressed as much as possible.
The “electronic device” according to the present invention is applied to a car navigation device mounted in the center of a dashboard of an automobile and provides one of the most preferable specific modes.

In order to solve the above problems, a driving method of an electro-optical device according to the present invention includes an electro-optical element that receives a supply of an image signal and changes a light emission mode or a light transmission mode thereof, An electro-optical device driving method for driving an electro-optical device capable of displaying images having different contents in each of two display ranges, wherein a still image is displayed in the first display range and a moving image is displayed in the second display range. In the case of displaying, the step of causing the display light to travel in the first direction corresponding to the first display range within the length of the first period within one frame period having a predetermined length; And a step of causing the display light to travel in a second direction corresponding to the second display range by a length of a second period that is smaller than the length of one period.
According to the present invention, substantially the same effect as that obtained by the above-described electro-optical device according to the present invention can be achieved.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the following, description may be made on the assumption that the two-image display device 100 according to the first embodiment is mounted in the center of a dashboard of an automobile.
The two-image display device 100 according to the first embodiment includes an illumination device 10, a liquid crystal device 20, an optical body 30, a driving device 50, and a timing control circuit 60. The illumination device 10 is installed on the back side of the liquid crystal device 20 to illuminate the liquid crystal device 20. The optical body 30 is interposed between the illumination device 10 and the liquid crystal device 20.

As shown in FIG. 1, the illumination device 10 includes a light guide plate 11 and a light source 15.
Among these, the light source 15 is, for example, a white LED (Light Emitting Diode). As shown in FIG. 1, the light source 15 has a relatively long rod shape or rectangular parallelepiped shape. The light source 15 is arranged such that its longitudinal direction is along a side end of a light guide plate 11 described later. The light emitted from the light source 15 enters the light guide plate 11 from the side end thereof.

The light guide plate 11 is a light transmissive optical member having a substantially flat plate shape. The light guide plate 11 has a function of spreading the light incident from the light source 15 over the entire light guide plate 11 and emitting the light toward the liquid crystal device 20. The upper surface of the light guide plate 11 in FIG. 1, that is, the surface facing the liquid crystal device 20 is a surface from which light is emitted toward the liquid crystal device 20 and serves as a light emitting surface.
In order to assist this function, the light guide plate 11 includes a diffusion plate and a reflection plate (both not shown). Among these, the diffusion plate has a function of appropriately diffusing the light incident on the light guide plate 11. Specifically, for example, a flat plate or the like in which minute protrusions having a wedge-shaped cross section are arranged in parallel along a predetermined direction may be applicable. Further, the reflection plate is provided on the back surface of the light guide plate 11 (the lower surface in the drawing, which cannot be represented in FIG. 1). The reflector is made of a material having a relatively high light reflection performance such as aluminum. Thereby, the light which escapes from the inside of the light-guide plate 11 is enclosed in the inside.

  As illustrated in FIG. 1 and the like, the liquid crystal device 20 includes a first substrate 21 and a second substrate 22 that face each other. Liquid crystal (not shown) is sealed in the gap between the first substrate 21 and the second substrate 22. A liquid crystal that responds at high speed such as an OCB (Optically Compensated Bend) mode is preferably used. On the surface of the second substrate 22 facing the liquid crystal, a plurality of pixel electrodes 24 corresponding to each pixel of the image are arranged in a matrix over the X and Y directions intersecting each other. The orientation of the liquid crystal sandwiched between the first substrate 21 and the second substrate 22 changes according to the potential difference between each pixel electrode 24 and the counter electrode (not shown) on the surface of the first substrate 21. Therefore, the ratio (transmittance) of the amount of light transmitted to the observation side in the emitted light from the illumination device 10 is controlled for each pixel electrode 24.

The optical body 30 includes a lenticular lens 32 and a shutter device 33.
Among these, the shutter device 33 basically has the same configuration as the liquid crystal device 20 described above. That is, the shutter device 33 includes a first substrate and a counter electrode provided on the first substrate, a second substrate and a pixel electrode provided on the first substrate, and a liquid crystal (all not shown) sandwiched between the first and second substrates. Prepare.
However, unlike the liquid crystal device 20, the shutter device 33, as shown in FIG. 2, transitions between only two states that transmit or do not transmit light for each pixel column extending along the Y direction. . A more detailed description will be given again when the shutter driving circuit 53 is described later.

As shown in FIG. 2, a plurality of lenticular lenses 32 are arranged in the X direction. Each lenticular lens 32 extends in the Y direction. When viewed from the direction perpendicular to the light emitting surface, one lenticular lens 32 overlaps two pixel columns adjacent to each other in the X direction in the shutter device 33. That is, one lenticular lens 32 corresponds to the two pixel rows that constitute the shutter device 33.
The lenticular lens 32 advances the light emitted from the light guide 11 in the direction DR or in the direction DA according to the state of the shutter device 33. The direction DR and the direction DA are different directions. In FIG. 2, the pixel row of the shutter device 33 located in the right half of each lenticular lens 32 in the drawing is in a light-transmitting state, so that light travels along the direction DR with a solid line. ing.

  For this reason, if the light from the light source 15 passes through the lenticular lens 32 from the light guide 11 through the shutter device 33 and then travels in the direction DR, the light travels toward the driver's seat. On the other hand, if the light travels in the direction DA, it can be realized that the light travels toward the passenger seat. In short, according to the above configuration, different images can be displayed in each of the two display ranges.

  The drive device 50 drives the illumination device 10, the shutter device 33, and the liquid crystal device 20. As shown in FIG. 1, the driving device 50 includes an illumination driving circuit 52, a shutter driving circuit 53, and a liquid crystal driving circuit 55. In addition, the aspect of mounting the driving device 50 is arbitrary. For example, the illumination drive circuit 52 is mounted on the illumination device 10 and the liquid crystal drive circuit 54 is mounted on the liquid crystal device 20, or the illumination drive circuit 52, the shutter drive circuit 53, and the liquid crystal drive circuit 54 are mounted on a single integrated circuit. The configuration is adopted.

The illumination drive circuit 52 controls turning on / off of the light source 15 of the illumination device 10.
The shutter drive circuit 53 controls the state transition of the shutter device 33. As described above, the shutter device 33 transitions between only two states of light transmission or non-transmission for each pixel row. More specifically, the shutter device 33 is as follows.
That is, first, a first state is defined in which the pixel columns located in the odd-numbered columns in the shutter device 33 are in the light transmissive state and the pixel columns located in the even-numbered columns are in the light non-transmissive state. To do. On the other hand, on the contrary, a second state is defined in which the odd-numbered pixel columns are in a light non-transmissive state and the even-numbered pixel columns are in a light transmissive state.
The shutter drive circuit 53 controls the shutter device 33 so that these first and second states appear alternately. At that time, the duration of the first state, the duration of the second state, and the duration of the interval between these two states are appropriately set by the timing control circuit 60 described later.
As described above, the shutter drive circuit 53 appropriately controls the state of the shutter device 33 according to the time.

  The liquid crystal drive circuit 54 controls the state of the liquid crystal device 20. The liquid crystal driving circuit 54 may include a scanning line driving circuit and a data line driving circuit. The scanning line driving circuit issues a selection signal in units of one pixel row and defines a horizontal scanning period. The data line driving circuit supplies an image signal to the pixel row selected by the scanning line driving circuit (that is, writes the image signal). The time from the start of the supply of the image signal to the first pixel row to the supply of the image signal to the final pixel row is the vertical scanning period. As a result, for each pixel, the potential difference between the pixel electrode and the counter electrode is set appropriately, and the alignment state of the liquid crystal sandwiched therebetween is appropriately adjusted.

The timing control circuit 60 controls the operation timing of the illumination drive circuit 52, the shutter drive circuit 53, and the liquid crystal drive circuit 54 described above. That is, the timing control circuit 60 controls the state transition timings of the light source 15, the shutter device 33, and the liquid crystal device 20 via these circuits 52, 53, and 54.
The timing control circuit 60 is supplied with an input image signal SIN from an external device (not shown). In general, the input image signal SIN is a signal that designates the potential difference to be held by each pixel of the driver side image and the passenger side image having different contents.

  Hereinafter, the operation of the two-image display device 100 having the above-described configuration will be described with reference to FIGS. 3 and 4 in addition to FIGS. 1 and 2 already referred to. Note that the start and end of the operations of various elements such as the liquid crystal device 20, the light source 15, and the shutter device 33 in the following description depend on the control by the timing control circuit 60 via the driving device 50 unless otherwise specified. .

  First, in the timing chart of FIG. 3, “one frame” means one unit period required for one set of display of an image displayed on the driver side and an image displayed on the passenger side. . The repetition frequency in units of this period is 60 Hz as shown in the figure in the first embodiment.

In FIG. 3, the image signal SIN is first written to the liquid crystal device 20. The writing of the image signal SIN is performed for each pixel row of the liquid crystal device 20 as described above, and is performed for all the pixels by sequentially scanning from the first pixel row to the last pixel row. Further, the writing of the first pulse in FIG. 3 is performed based on the contents of the image to be displayed on the driver's seat side.
In FIG. 3, this series of writing operations is represented by one pulse. That is, the width of the pulse substantially corresponds to the vertical scanning period. This is the same for all the pulses representing image signal writing appearing in the following description (that is, the pulses depicted at the top of FIGS. 4 to 7).

When the writing of the image signal SIN is completed, the response of the shutter device 33 starts at the same time as the response of the liquid crystal in the liquid crystal device 20 starts. The response of the shutter device 33 here is a response for displaying an image on the driver's seat side, as can be seen from the fact that “driver's seat side shutter transmission timing” is described in FIG. 3. That is, as shown in FIG. 2, a response is made such that the pixel column corresponding to the right half of the lenticular lens 32 in the drawing is in a light-transmitting state and the adjacent pixel column is in a light-impermeable state.
The responses of the liquid crystal device 20 and the shutter device 33 should ideally rise vertically, but in the actual liquid crystal, a response having a constant time constant is usually made as shown in the figure. is there. Further, since the liquid crystal device 20 and the shutter device 33 have basically the same configuration as described above, the response is basically the same as shown in FIG.

When the liquid crystal device 20 and the shutter device 33 pass through the transient state that continues immediately after rising and reach a steady state, the light source 15 is subsequently turned on. Thereby, the light from the light source 15 passes through the inside of the light guide plate 11 and is emitted from the light emitting surface, and reaches the shutter device 33.
Here, since the shutter device 33 is in the state shown in FIG. 2 as described above, the light is a portion of the pixel column in the light transmission state among the pixel columns constituting the shutter device 33. Only transparent. Then, this light further passes through the liquid crystal device 20 while traveling along the direction DR as shown in the figure when passing through the lenticular lens 32.

  As a result, an image having a certain content is displayed to the driver. Here, the image having a certain content is, for example, an image related to a road map that also displays the current position of the vehicle, and the image shows almost no movement (note that Hereinafter, for the sake of convenience, this may be referred to as “still image”).

The light source 15 is turned off after a certain period of time has elapsed since the driver side image was displayed in this manner. At the same time, the state of the shutter device 33 changes. That is, in the previous stage, the pixel column that is in the light transmission state is in the light non-transmission state. As a result, the shutter device 33 enters the interval state between the first and second states described above. Incidentally, FIG. 3 shows that a certain amount of time is required until the shutter device 33 reaches the steady state even in the transition from the light transmission state to the non-transmission state.
Note that the fixed period here is particularly referred to as a “driver's seat side light emission period” as shown in FIG.

Subsequently, the image signal is written to the liquid crystal device 20 again. This writing is performed based on the contents of the image to be displayed on the passenger seat side.
Following this, the response of the shutter device 33 starts again in response to the start of the response of the liquid crystal in the liquid crystal device 20. The response of the shutter device 33 here is a response for displaying an image on the passenger seat side, contrary to the case described above. That is, referring to FIG. 2, a response is made such that the pixel row corresponding to the left half of the lenticular lens 32 in the drawing is in a light transmission state and the adjacent pixel row is in a light non-transmission state. (Consider a case where the hatched portion and the non-hatched portion in FIG. 2 have opposite relations. Refer to the broken line in FIG. 2). In FIG. 3, this is expressed as “passenger side shutter transmission timing”.

  When the liquid crystal device 20 and the shutter device 33 reach a steady state, the light source 15 is turned on again. As a result, similarly to the case described above, the light from the light source 15 passes through the inside of the light guide plate 11 and is emitted from the light emitting surface, and reaches the shutter device 33. However, in this case, the light that has passed through the light guide plate 11 passes through the liquid crystal device 20 while traveling along the direction DA in FIG.

  Thus, an image having a certain content is displayed for the passenger sitting in the passenger seat. Here, an image having a certain content is, for example, a movie based on a DVD, a video tape, a TV video signal, etc., and a relatively intense movement is recognized on the image (hereinafter referred to as “image”). For convenience, this is sometimes referred to as “moving image”).

The light source 15 is turned off again after a certain period of time has elapsed since the passenger seat side image is displayed in this manner. Note that the certain period here is referred to as a “passenger side light emission period” as shown in FIG. 3.
What is characteristic here is that, as shown in FIG. 3, the passenger seat side light emission period is shorter than the driver seat side light emission period described above. This means that only the light source 15 is quickly extinguished even though the pixel row in the shutter device 33 in the light transmission state still maintains the state ( (See thick line and broken line in FIG. 3)
Thus, in the first embodiment, so-called intermittent display is performed for the image display on the passenger seat side.
Note that, since the luminance decreases as the light emission period becomes shorter, the light source luminance may be increased in the passenger seat side light emission period as necessary.

  Thereafter, the above operations are sequentially repeated.

According to the two-image display device 100 of the first embodiment as described above, the following effects are achieved.
(1) In the two-image display device 100 of the first embodiment, as described above, the length of the passenger seat side light emission period is shorter than that of the driver seat side light emission period. Thereby, what is called intermittent display is performed for the image display to the passenger seat side. Therefore, according to the first embodiment, even when a moving image is displayed as an image on the passenger seat side, the display light is prevented from entering the eyes of the viewer for a relatively long period of time. Therefore, the occurrence of moving image blur can be suppressed as much as possible.
On the other hand, since the driver seat side light emission period is relatively long, the generation of flicker is suppressed as much as possible.

Such an effect can be understood more clearly with reference to FIG. 4 which is a comparative example with respect to the first embodiment. In FIG. 4, although one set of image display on the driver's seat side and the passenger seat side is performed during one frame period, there is no difference from the first embodiment, but the driver side light emission period and the passenger seat side The length of the light emission period is the same as in FIG. In addition, the start and end of the light emission period are synchronized with the transmission timing of the shutter device 33. In this way, when the time-division display equivalent to both is performed, when the image on the passenger seat side is a moving image, there is an increased risk of moving image blurring. Incidentally, in the above-mentioned Patent Document 1, it is proposed to exceed the time-division display equivalent to both, and rather, to set the length of the passenger side light emission period longer than that of the driver side light emission period. If this is the case, the possibility of occurrence of such a failure will be further increased.
In 1st Embodiment, generation | occurrence | production of the above malfunctions is suppressed as much as possible.

(2) In the two-image display device 100 according to the first embodiment, the length of the light emission period on the driver's seat side and the passenger seat side is controlled by a more direct means such as turning on / off the light source 15. Therefore, it is possible to reduce power consumption and avoid unnecessary consumption of the light source 15 as compared with the case where the light source 15 is kept on.

Second Embodiment
Hereinafter, a second embodiment according to the present invention will be described with reference to FIG. Note that the second embodiment and the third and subsequent embodiments described later have characteristic changes in the specific operation mode of the two-image display device 100 as compared to the first embodiment described above. The configuration itself of the two-image display device 100 is exactly the same as in the first embodiment. Therefore, the description thereof is omitted below.

In the two-image display device 100 of the second embodiment, as shown in FIG. 5, first, there is a change regarding the writing timing of the image signal as compared with FIG. That is, in this FIG. 5, the time from the writing timing of the driver seat side image to the writing timing of the passenger seat side image and the time from the writing timing of the passenger seat side image to the writing timing of the driver seat side image in the next frame (Hereinafter, only the description of the second embodiment is referred to as “interval time”), the former is longer than the latter. That is, in the second embodiment, the period related to “driver's seat side display” and the period related to “passenger seat side display” are time-divided unevenly within one frame period.
Further, in accordance with such a change, the shutter transmission timing and the illumination timing are also changed in FIG. That is, since the interval time is shortened compared to FIG. 3, the state transition timing of the shutter device 33 and the turn-off timing of the light source 15 are also advanced compared to FIG.

  It is obvious that even with such a configuration, it is possible to obtain operational effects that are essentially not different from those of the first embodiment. This is because even in this case, the length of the passenger side light emission period remains relatively shorter than that of the driver side light emission period. This is because the occurrence of is suppressed as much as possible. Further, there is no essential change in that the occurrence of flicker in the driver's seat side image is also suppressed as much as possible.

<Third Embodiment>
Hereinafter, a third embodiment according to the present invention will be described with reference to FIG.
In the two-image display device 100 of the third embodiment, as shown in FIG. 6, there is a change related to how the driving performance side light emission period and the passenger side light emission period are allocated within one frame period as compared with FIG. 3. That is, in FIG. 6, the driver seat side light emission period is first provided as the first period, and then the passenger seat side light emission period is provided, which is no different from FIG. 3.

However, after that, in FIG. 6, unlike FIG. 3, the driver seat side light emission period is provided again as the third period. Incidentally, these three periods are all the same length. Further, even in the passenger side light emission period, the light source 15 is not turned off before the shutter device 33 reaches the interval state as in the first embodiment, but the pixel row in the shutter device 33 is not illuminated. The light source 15 is turned off in conjunction with reaching the transmission state.
Thus, the third embodiment is characterized in that three light emission periods are conveniently provided in one frame, of which the driver seat side light emission period occupies the majority.

  It is obvious that even with such a configuration, it is possible to obtain operational effects that are essentially not different from those of the first embodiment. This is because even in this case, the length of the passenger side light emission period remains relatively shorter than that of the driver side light emission period. This is because the occurrence of is suppressed as much as possible. Further, there is no essential change in that the occurrence of flicker in the driver's seat side image is also suppressed as much as possible.

  In addition, in the third embodiment, since a larger number of light emission periods are set within one frame period, a relatively high-speed switching is performed. Will increase. Therefore, according to this embodiment, it is possible to more effectively enjoy the flicker reduction effect in the driver's seat side image. Further, for the same reason, it is possible to more effectively enjoy the effect of reducing the motion blur in the passenger side image.

<Fourth embodiment>
Hereinafter, a fourth embodiment according to the present invention will be described with reference to FIG.
In the two-image display device 100 of the fourth embodiment, as shown in FIG. 7, there is a change related to how the driving performance side light emission period and the passenger side light emission period are allocated within one frame period, as compared with FIG. 3. That is, in FIG. 6, the driver seat side light emission period is first provided as the first period, and then the passenger seat side light emission period is provided, which is no different from FIG. 3.

However, after that, in FIG. 6, unlike FIG. 3, the driver seat side light emission period is provided again as the third period, and further, the passenger seat side light emission period is provided again as the fourth period. Yes. Incidentally, these four periods are all the same length. Further, even in the passenger side light emission period, the light source 15 is not turned off before the shutter device 33 reaches the interval state as in the first embodiment, but the pixel row in the shutter device 33 is not illuminated. The light source 15 is turned off in conjunction with reaching the transmission state.
Thus, the fourth embodiment is characterized in that four light emission periods are conveniently provided in one frame.
Note that the image displayed at least on the passenger side may be 120 Hz. For example, the image displayed on the passenger side generates an image (intermediate image) between frames from a 60 Hz image signal sent, and generates two images shown in FIG. 7 as 120 Hz image signals. It is preferable to improve motion blur by allocating and displaying each period for the passenger side display.

According to such a form, the effect peculiar to above-mentioned 3rd Embodiment can be enjoyed more effectively. This is because in this case, since more light emission periods are set within one frame period, relatively faster switching is performed. This is because it can be seen that it has further increased.
Thus, in the fourth embodiment, it is possible to more effectively enjoy the flicker reduction effect in the driver's seat side image. For the same reason, it is possible to more effectively enjoy the effect of reducing the motion blur in the passenger side image.

In the case of performing image display at a substantially increased frame rate as in the fourth embodiment and the previous third embodiment, the image displayed for the second time within one frame period is It is preferable to use an intermediate image between the image displayed at the first time and the image to be displayed in the next frame. By doing so, the motion of the moving image can be made smoother, and accordingly, the occurrence of moving image blur can be suppressed accordingly.
Incidentally, this concept can be easily applied to the case where one frame period is divided into four or more sections.

Although the embodiments according to the present invention have been described above, the electro-optical device and the driving method thereof according to the present invention are not limited to the above-described embodiments, and various modifications can be made.
First, in each of the above embodiments, for convenience of explanation, the case where a still image is displayed on the driver's seat side and a moving image is displayed on the passenger seat side is described in mind, but the two-image display device according to each of the embodiments is described. Of course, the operation mode of 100 is not limited to this. Needless to say, when the car is stopped, a moving image with the same content may be displayed on the driver's seat and passenger's side, or regardless of whether the vehicle is running or stopped. Still images having different contents may also be displayed on the side. In addition, although there are various variations, in any case, the content of the image to be displayed in the two-image display device 100 according to each of the above embodiments should be determined freely according to the time.
As a more preferable aspect of the present invention, it is possible to make the operation mode of the two-image display device 100 different, such as selection between the embodiments according to such various variations. It is preferable to provide operation mode selection means (for example, if moving images are displayed on both the driver's seat side and the passenger seat side, the fourth embodiment, moving images on the driver seat side and still images on the passenger seat side) If it is displayed, the period according to the “driver's side display” and the “passenger side display” according to the first embodiment may be exchanged.

  In each of the above embodiments, the case where the two-image display device 100 is mounted on an automobile has been described in mind. However, as disclosed in the following <Application>, the present invention is applicable to various electronic devices. Of course, the present invention can be applied to equipment, and is not limited to a car-mounted form.

The “electro-optical device” in the present invention refers to a device that can display a predetermined image by including an electro-optical element. Here, the “electro-optical element” is an element whose optical characteristics such as transmittance and luminance change when an electric signal (current signal or voltage signal) is supplied. The predetermined image can be displayed by arranging a plurality of electro-optical elements in an appropriate manner and appropriately controlling them.
Specific devices or embodiments that fall under the concept of the “electro-optical device” are as follows, for example.
That is, a display panel using a light emitting element such as an inorganic EL (ElectroLuminescent), an organic EL, or a light emitting polymer, and a microcapsule including a colored liquid and white particles dispersed in the liquid is used as an electro-optical material. Electrophoretic display panel, twist ball display panel using twist balls painted in different colors for areas of different polarities as electro-optical material, toner display panel using black toner as electro-optical material, or helium And a plasma display panel using a high pressure gas such as neon as an electro-optical material.
In these cases, when the “electro-optical element” itself has a light emitting function, the “electro-optical element” also serves as the “light source” in the present invention.

<Application example>
Next, an electronic apparatus using the two-image display device 100 according to the present invention will be described. FIGS. 8 to 11 show a form of an electronic apparatus that employs the two-image display device 100 according to any of the forms described above.

  FIG. 8 is a perspective view showing the configuration of a mobile personal computer that employs the display device 100. The personal computer 2000 includes a two-image display device 100 that displays various images, and a main body 2010 on which a power switch 2001 and a keyboard 2002 are installed.

  FIG. 9 is a perspective view showing a configuration of a mobile phone to which the two-image display device 100 is applied. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and a two-image display device 100 that displays various images. By operating the scroll button 3002, the screen displayed on the two-image display device 100 is scrolled.

  FIG. 10 is a perspective view showing a configuration of a personal digital assistant (PDA) to which the two-image display device 100 is applied. The portable information terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the display device 100 that displays various images. When the power switch 4002 is operated, various information such as an address book and a schedule book are displayed on the two-image display device 100.

FIG. 11 is a diagram illustrating a configuration of a car navigation device to which the two-image display device 100 is applied. The car navigation device 5000 includes a plurality of operation buttons 5001 and a two-image display device 100 that displays various images. When the operation button 5001 is operated, various information (hereinafter referred to as “operation related information”) such as a road map including route information, traffic jam information, or recommended sightseeing spots is displayed on the two-image display device 100. .
In the car navigation device 5000, the two-image display device 100 can be used to display a moving image based on a DVD, a video tape, a television reception signal, or the like.
Since the car navigation device 5000 is equipped with the two-image display device 100 according to the above-described various embodiments, an image displayed to the driver sitting in the driver seat 5100 and a passenger sitting in the passenger seat 5200 are displayed. The image displayed for can be different. In this case, preferably (especially during operation of the vehicle), an image related to the operation-related information is displayed on the driver's seat 5100 side, and the moving image or the like is displayed on the passenger seat 5200 side.
According to such a car navigation device 5000, since the device 5000 is equipped with the two-image display device 100 according to each of the above embodiments, as already described in detail, in the image on the passenger seat 5200 side, On the other hand, the occurrence of moving image blur is suppressed as much as possible, while the occurrence of flicker is suppressed as much as possible in the image on the driver's seat 5100 side.

  Electronic devices to which the two-image display device 100 according to the present invention is applied include the digital still camera, the television, the video camera, the pager, the electronic notebook, the electronic paper, and the calculator in addition to the devices illustrated in FIGS. , Word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices equipped with touch panels, and the like.

It is a block diagram which shows the structure of the two-image display apparatus which concerns on 1st Embodiment of this invention. It is a side view of the structure of the two-image display apparatus of FIG. 2 is a timing chart for explaining the operation of the two-image display device of FIG. 1. 4 is a timing chart for explaining an operation as a comparative example of FIG. 3; It is a timing chart for demonstrating operation | movement of the two-image display apparatus which concerns on 2nd Embodiment of this invention. It is a timing chart for demonstrating operation | movement of the two-image display apparatus which concerns on 3rd Embodiment of this invention. It is a timing chart for demonstrating operation | movement of the two-image display apparatus which concerns on 4th Embodiment of this invention. It is a perspective view which shows the form (personal computer) of the electronic device which concerns on this invention. It is a perspective view which shows the form (cellular phone) of the electronic device which concerns on this invention. It is a perspective view which shows the form (mobile information terminal) of the electronic device which concerns on this invention. It is a figure which shows the form (car navigation apparatus) of the electronic device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Two image display apparatus, 10 ... Illuminating device, 11 ... Light guide, 15 ... Light source, 20 ... Liquid crystal device, 21 ... 1st board | substrate, 22 ... 2nd board | substrate, 24 ... Pixel Electrode 30... Optical body 32. Lenticular lens 33 33 Shutter device 50 Drive device 52 Illumination drive circuit 53 Shutter drive circuit 54 Liquid crystal drive circuit 60 Timing control circuit, 5000 ... Car navigation system

Claims (5)

An electro-optical device that includes an electro-optical element that receives a supply of an image signal and changes a light emission mode or a light transmission mode, and can display different images in a first display range and a second display range. ,
A light source;
A light direction determining means for causing display light having the light source as a generation source to travel in a first direction corresponding to the first display range or a second direction corresponding to the second display range;
Still image on the first display range, in the case of displaying a moving image on the second display range,
By turning on or off the light source within one frame period having a predetermined length, the length of the first period in which the display light is advanced in the first direction becomes the second direction. A light emission period control means for controlling at least one of the light source and the light direction determination means so as to be equal to or longer than the length of the second period to be advanced;
An electro-optical device comprising: The light direction determining means includes
A state in which a part of the light emitted from the light source in the first region is allowed to pass and a remaining part of the light is blocked in the second region; and a part of the light emitted from the light source in the first region And a shutter means capable of transitioning between a state in which the rest of the light is allowed to pass through in the second region,
So that light that has passed through the first region in the shutter means travels in the first direction, and light that has passed through the second region in the shutter means travels in the second direction, Lens means for refracting the light;
The electro-optical device according to claim 1, comprising: The shutter means includes a liquid crystal element,
Depending on the alignment state of the liquid crystal constituting the liquid crystal element, the light is allowed to pass through or shielded.
The electro-optical device according to claim 2. The light emission period control means includes
Image signal supply control means for controlling the supply timing of the image signal to the electro-optic element;
The image signal supply control means
In one frame period, the first supply timing of the image signal for displaying the image for the first display range to the electro-optical element and the image signal for displaying the image for the second display range Controlling the supply timing so that the time between the second supply timing to the electro-optical element is longer than the remaining time in the one frame period, and
The light emission period control means includes
Set the first period between the first and second supply timings;
Setting the second period within the remaining time;
The electro-optical device according to any one of claims 1 to 3. The electro-optical device according to claim 1 is provided.
An electronic device characterized by that.

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