JP2003076342A - Liquid crystal device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semitransmissive reflection type liquid crystal device in which color reproducing range is made wide when conducting displaying ion a transmissive mode and display quality is made superior. SOLUTION: A semitransmissive reflection type liquid crystal device 1 is provided with a liquid crystal panel 30 having a color filter 13 and a back light (an illumination means) 40. The color filter 13 is provided with a plurality of kinds of coloring layers 13R to 13B having different colors. The back light 40 is provided with a plurality of kinds of light emitting elements 41R to 41B which emit color light beams corresponding to the colors of the layers 13R to 13B respectively. When displaying is conducted in a transmissive mode, one frame is divided into a plurality of fields, and the plurality of kinds of elements 41R to 41B are made to sequentially emit light in one frame. Then, the displaying is conducted by field sequential driving in which the panel 30 is driven for every one field in synchronism with the light emission timing of the elements 41R to 41B.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a wide display color reproduction range (high color purity) when displaying in a transmission mode.
The present invention relates to a semi-transmissive reflective liquid crystal device having excellent display quality, and an electronic apparatus including the liquid crystal device.

[0002]

2. Description of the Related Art A transmissive liquid crystal device for displaying by utilizing light emitted from a built-in backlight (illuminating means),
2. Description of the Related Art There is known a reflective liquid crystal device that performs display by using external light such as sunlight. The former liquid crystal device has an advantage that the display can be visually recognized even in a dark place where the brightness of external light is insufficient, but it has a problem that the backlight is always turned on and therefore the power consumption increases. On the other hand, since the latter liquid crystal device does not have a built-in illumination means, it is possible to save power, but there is a problem in that it is difficult to visually recognize the display in a dark place.

Therefore, as a liquid crystal device having both advantages, in a dark place, a built-in backlight is turned on, and light emitted from the backlight is used to perform display in a transmissive mode to brighten external light. In a bright place, a transflective liquid crystal device capable of displaying in a reflection mode by utilizing external light is known. In the transflective liquid crystal device, the display can be visually recognized even in a dark place, and the display can be performed by using external light in a bright place. Therefore, it is necessary to always turn on the backlight. It is possible to achieve power saving compared to. In the conventional transflective liquid crystal device, a white light source such as a cold cathode tube that emits white light is widely used as a light source of a backlight.

The semi-transmissive reflective liquid crystal device includes a semi-transmissive reflective layer on the liquid crystal layer side surface of a substrate located on the opposite side of the viewing side from a pair of substrates that are opposed to each other with a liquid crystal layer interposed therebetween. A semi-transmissive reflection type liquid crystal device, which has a schematic structure and is provided with a color filter on one substrate and is capable of color display, is also known. The semi-transmissive reflective layer is composed of a reflective layer having both light transmissive property and light reflective property, a reflective layer having slit-shaped openings for each dot, and the like. In addition,
The reflective layer having both light-transmitting property and light-reflecting property can be formed by forming a thin film of a light-reflecting material, and the whole thereof is a light-transmitting part that transmits light and a light-reflecting part that reflects light. On the other hand, in the reflective layer having an opening, the opening functions as a light transmitting portion and the other portions function as a light reflecting portion.

[0005]

In the transflective liquid crystal device, the light emitted by the backlight is sequentially transmitted through the substrate on the backlight side, the liquid crystal layer, and the substrate on the observer side and emitted to the observer side. By utilizing the fact that it is performed, it is possible to perform display in the transparent mode. In addition, by utilizing the fact that external light is sequentially transmitted through the viewer-side substrate and the liquid crystal layer, is reflected by the semi-transmissive reflective layer provided on the backlight-side substrate, and is emitted to the viewer side. The display in the reflection mode can be performed.

Therefore, in the transflective liquid crystal device capable of color display, when displaying in the transmissive mode,
The light that has entered the liquid crystal panel is transmitted through the color filter only once and then emitted to the viewer side, whereas when the display is performed in the reflective mode, the light that has entered the liquid crystal panel is the semi-transmissive reflective layer. The light is transmitted through the color filter and emitted to the observer side twice before and after being reflected by the semi-transmissive reflective layer.

As a color filter, a filter provided with a pigment dispersion type colored layer colored red (R), green (G) and blue (B) is widely used. Here, FIG. 11 shows an example of the spectral characteristics (relationship between the wavelength of visible light (light having a wavelength of 380 to 780 nm) incident on the liquid crystal panel and the transmittance) of each colored layer of the pigment dispersion type color filter. In FIG. 11, R, G, and B show examples of the spectral characteristics of the red colored layer, the green colored layer, and the blue colored layer, respectively.

From FIG. 11, the red, green, and blue colored layers constituting the color filter are respectively red light (wavelength approximately 380).
~ 500 nm light), green light (wavelength approximately 500-600)
nm light) and blue light (light having a wavelength of approximately 600 to 780 nm) are mainly transmitted, but it is understood that visible light of all wavelengths is transmitted by 15% or more.
In other words, the light after passing through the respective colored layers of the color filter contains a light amount other than the color to be displayed, though the light amount is smaller than the light of the color to be displayed.
Since the amount of light other than the color to be displayed decreases as the number of times of transmission of the color filter increases, the color reproduction range of display increases (the color purity increases) as the number of times of transmission of the color filter increases. . Therefore, the conventional transflective liquid crystal device has a problem that the color reproduction range of the display when the display is performed in the transmissive mode is narrower than that when the display is performed in the reflective mode (the color purity is low). .

Therefore, the present invention has been made in view of the above circumstances, and a semi-transmissive reflection having a wide display color reproduction range (high color purity) and excellent display quality when performing display in the transmission mode. An object of the present invention is to provide a type liquid crystal device and an electronic apparatus including the liquid crystal device.

[0010]

As a result of studies to solve the above problems, the present inventor has invented the following liquid crystal device (semi-transmissive reflective liquid crystal device) of the present invention. A liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention has a semi-transmissive reflective layer formed on a surface of one substrate out of a pair of substrates which are opposed to each other with a liquid crystal layer interposed therebetween. A liquid crystal panel including a liquid crystal panel having a color filter on the viewing side of the semi-transmissive reflective layer, and an illuminating unit arranged on the side opposite to the viewing side of the liquid crystal panel, and performing display by switching between a transmissive mode and a reflective mode. In the device, the color filter includes a plurality of types of colored layers having different colors,
The illuminating unit includes a plurality of types of light emitting elements capable of respectively emitting colored light corresponding to the colors of the plurality of types of colored layers, and divides one frame into a plurality of fields when performing transmission mode display. However, within one frame, the plurality of types of light emitting elements of the illuminating means are made to sequentially emit light at the same time, and in accordance with the light emission timing of the light emitting elements, 1
It is characterized in that display is performed by field sequential driving, in which the liquid crystal panel is driven for each field.

That is, in the conventional transflective liquid crystal device, a white light source is used as the light source of the illuminating means (backlight), whereas in the transflective liquid crystal device of the present invention, it is used as the light source of the illuminating means. , While using a plurality of types of light-emitting elements capable of respectively emitting colored light corresponding to the colors of a plurality of types of colored layers constituting the color filter, in the reflection mode, while performing display by normal driving similar to the conventional, The transmissive mode is characterized by performing display by field sequential driving.

Since the light emitting element such as a light emitting diode is configured to emit a specific color light, the color purity of the emitted color light is extremely high. As an example, FIG. 12 shows an example of the relationship between the wavelength of light emitted from a light emitting diode that emits red light (R), green light (G), and blue light (B) and the relative emission intensity. As shown in FIG. 12, the relative emission intensity of the light emitted from each light emitting diode has a peak at a specific wavelength, and the wavelength distribution of the light emitted from each light emitting diode is narrow, and the color of the emitted light is It can be seen that the purity is extremely high.

As described above, in the reflection mode in which the light incident on the liquid crystal panel is transmitted through the color filter twice and is emitted to the observer side, display is performed by normal driving, whereas the light incident on the liquid crystal panel is colored. In the transmission mode in which the light is transmitted through the filter only once and is emitted to the observer side, one frame is divided into a plurality of fields, and a plurality of types of light-emitting elements that emit color light with high color purity are sequentially turned on for a field sequential manner. By performing the display by driving, the color reproduction range of the display in the transmissive mode can be widened (the color purity can be increased) without deteriorating the display quality in the reflective mode. A transflective liquid crystal device having excellent quality can be provided.

In the liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention, the display mechanism for displaying in the transmissive mode by field sequential driving will be described in detail in the section of "Embodiment of the invention". Each colored layer that constitutes the color filter is provided corresponding to each dot of the liquid crystal panel, and one pixel is displayed by a plurality of dots on which the plurality of types of colored layers are formed, and the field sequential drive is performed. When a transmissive mode is displayed by means of, by supplying a signal to each dot of the liquid crystal panel independently, each color light emitted by each light emitting element transmits only the dot on which the colored layer of the same color is formed. Therefore, it is preferable to drive the liquid crystal panel.

With such a configuration, when displaying the transmission mode by field sequential driving,
During the lighting period of the light emitting element that emits light of a certain color, only the dots in which the colored layer of that color is formed are lit, and both the color of the light emitted from the illumination means and the color of the colored layer overlap. Since it is visible and the colored layers of other colors are not visible,
It is possible to further widen the color reproduction range (higher color purity) of the display when performing the transmission mode display, and it is possible to obtain a higher quality display.

However, in the case of such a configuration, since it is necessary to divide one frame into a plurality of fields and independently supply a signal to each dot of the liquid crystal panel for each field to drive the liquid crystal panel, As the circuit structure of the liquid crystal panel drive circuit for driving the liquid crystal panel becomes complicated,
It is necessary to increase the response speed of the liquid crystal, which complicates the structure of the liquid crystal panel.

Further, in the liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention, each colored layer forming the color filter is provided corresponding to each dot of the liquid crystal panel, and the plurality of types of colored layers are provided. In addition to displaying one pixel by a plurality of dots formed with, the same signal is supplied to the plurality of dots for displaying one pixel when displaying in the transmissive mode by the field sequential drive, and the liquid crystal panel May be configured to be driven.

In a pigment dispersion type color filter provided in a general liquid crystal device, as described with reference to FIG. 11, each colored layer constituting the color filter is
Although it is configured to mainly transmit light of a specific wavelength, it transmits visible light of all wavelengths, so instead of supplying a signal to each dot of the liquid crystal panel independently, a plurality of pixels that display one pixel are displayed. The same signal can be supplied to the dots to drive the liquid crystal panel.

With such a configuration, when displaying the transmission mode by field sequential driving,
During the lighting period of the light emitting element that emits light of a certain color, a plurality of dots that display one pixel are lit, and the colored light emitted by the light emitting element is mainly the dots on which the colored layer of that color is formed. The light is transmitted and emitted, but also the dots formed with the colored layers of other colors are transmitted and emitted to perform display.

Therefore, when displaying in the transmissive mode, a signal is independently supplied to each dot of the liquid crystal panel, and each color light emitted by the light emitting element transmits only the dot in which the colored layer of the same color is formed. As compared with the case of the above configuration, the amount of light emitted to the observer side can be increased, and a brighter display can be obtained.

Further, when the same signal is supplied to a plurality of dots for displaying one pixel and the liquid crystal panel is driven as described above, a signal is supplied to each dot of the liquid crystal panel independently, and the liquid crystal panel is controlled. The circuit structure of the liquid crystal panel drive circuit for driving the liquid crystal panel can be simplified as compared with the case of driving.

However, in a certain field, the color of the colored layer other than the color of the light emitted from the light-emitting element that is turned on is mixed and displayed, so that signals are independently supplied to each dot of the liquid crystal panel to emit light. The color reproduction range of the display is narrower than that in the case where each color light emitted by the element is configured to be transmitted only through the dots in which the colored layers of the same color are formed. However, as shown in FIG. 12, the present inventor has found that the color purity of the light emitted from the light emitting element is extremely high. Therefore, in a certain field, a coloring layer other than the color of the light emitted from the light emitting element that is turned on is formed. Even if mixed colors are displayed, compared to the transmissive mode display of the conventional transflective liquid crystal device that uses a white light source, the color reproduction range is wide (high color purity) and high quality display is possible. Found that you can get.

Further, when the liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention displays the transmission mode by the field sequential drive, the color of the light emitted from the light emitting element is changed for each field. Generated by the field sequential color signal generation circuit and a field sequential color signal generation circuit for generating a corresponding color image signal and a synchronization signal for synchronizing the light emission timing of the light emitting element and the drive timing for driving the liquid crystal panel On the basis of the color image signal and the sync signal, the liquid crystal panel drive circuit for driving the liquid crystal panel, and based on the sync signal generated by the field sequential color signal generation circuit,
It is preferable to further include an illuminating means lighting circuit for driving the illuminating means, and by adopting such a configuration, it is possible to display the transmission mode by the field sequential driving as described above.

Further, each colored layer forming the color filter is provided corresponding to each dot of the liquid crystal panel, and one pixel is displayed by a plurality of dots on which the plurality of kinds of colored layers are formed. By configuring the liquid crystal panel drive circuit so as to supply a signal to each dot of the liquid crystal panel independently, each dot of the liquid crystal panel is independently provided when the transmissive mode is displayed by the field sequential drive. The liquid crystal panel can be driven so that each color light emitted by the light emitting element by supplying a signal is transmitted only through the dots in which the colored layers of the same color are formed.

Further, each colored layer forming the color filter is provided corresponding to each dot of the liquid crystal panel, and one pixel is displayed by a plurality of dots formed with the plurality of kinds of colored layers. When the liquid crystal panel drive circuit is configured to supply the same signal to the plurality of dots for displaying one pixel of the liquid crystal panel, when performing the transmission mode display by the field sequential drive, It is possible to drive the liquid crystal panel by supplying the same signal to a plurality of dots which display one pixel.

Further, when the display in the transmission mode is performed, the display by the field sequential drive and all or a plurality of the plurality of types of light emitting elements are simultaneously turned on to emit white light, and for each frame, It is preferable that the liquid crystal panel can be switched between normal driving and driving.

In the liquid crystal device, a voltage is applied to the liquid crystal layer to change the arrangement of the liquid crystal molecules in the liquid crystal layer for display. However, in the case of display by field sequential drive, one frame is divided into a plurality of fields. Split into
Since the liquid crystal panel is driven for each field, voltage application to the liquid crystal layer (ON) and cancellation of voltage application to the liquid crystal layer (OFF) are performed compared to normal display in which the liquid crystal panel is driven for each frame. The power consumption increases because the number of times increases.

Therefore, when displaying in the transmissive mode, the user can switch between the display by field sequential driving and the display by normal driving, so that the color reproduction range is wide (color purity is high). If high quality display is desired, display is performed by field sequential drive, and display of the same quality as the conventional transflective liquid crystal device may be used, and normal drive display is used to reduce power consumption. Can be performed, which is preferable.

In the above liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention, the plurality of types of light emitting elements are:
It is possible to exemplify three types of light emitting elements that emit red light, green light, and blue light. When three types of light emitting elements that emit red light, green light, and blue light are used, white light is obtained by turning on all of these three types of light emitting elements, and in the transmissive mode of normal driving. The display can be realized.

Further, by providing the liquid crystal device (semi-transmissive reflection type liquid crystal device) of the present invention described above, a wide color reproduction range (high color purity) at the time of displaying in the transmissive mode and excellent display quality. An electronic device can be provided.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail. In addition, in each embodiment, description will be given with reference to the drawings, but in each drawing, in order to make each layer and each member recognizable in the drawing, different scales are used for each layer and each member. is there.

[First Embodiment] The structure of a transflective liquid crystal device according to the first embodiment of the present invention will be described. In the present embodiment, an application example of the present invention to an active matrix type liquid crystal device using a TFD (Thin-Film Diode) element as a switching element will be shown. FIG. 1 is an exploded perspective view showing the overall configuration of the transflective liquid crystal device of this embodiment. FIG. 2 is a partial cross-sectional view of the transflective liquid crystal device according to the present embodiment, in which the transflective liquid crystal device shown in FIG.
It is sectional drawing when it cut | disconnects along the A'line. 3 to 5
3 is a timing chart for explaining a display mechanism of the transflective liquid crystal device of the present embodiment. FIG. 6 shows an IC (Integrat) mounted on the transflective liquid crystal device of this embodiment.
(edCircuit) is a functional block diagram showing the internal structure.
1 and 2, the upper side is shown as the observer side (viewing side).

As shown in FIGS. 1 and 2, the transflective liquid crystal device 1 of the present embodiment has a liquid crystal layer 50 (not shown in FIG. 1).
A liquid crystal panel 30 composed of a color filter substrate (lower substrate) 10 and an element substrate (upper substrate) 20 that are opposed to each other with a liquid crystal panel interposed therebetween, and a backlight disposed on the side opposite to the viewing side of the liquid crystal panel 30. (Illuminating means) 40.

In practice, the color filter substrate 1
0, at least one of the element substrates 20 is provided with an external connection terminal at one end thereof, and the portion provided with the external connection terminal is located outside the opposing substrate, and The external connection terminal has an IC (Inte
grated circuit) is mounted directly, or a flexible printed circuit board (IC) that mounts an IC that has a liquid crystal panel drive circuit etc.
Are electrically connected, but for simplicity in the drawing,
The color filter substrate 10 and the element substrate 20 are shown as having the same area, and external connection terminals and ICs are omitted.

The backlight 40 is turned on only when the brightness of external light is insufficient and is used as an auxiliary illuminating means. The light emitting elements 41R, 41G, 41 serving as light sources are provided.
B, and a light guide plate 42 that guides the light emitted by these light emitting elements 41R to 41B to the liquid crystal panel 30 side. The light emitting elements 41R, 41G, and 41B are elements capable of emitting red light, green light, and blue light, respectively. Examples of such light emitting element include a light emitting diode (LED). As described with reference to FIG. 12 in the section “Means for solving the problem”, the light emitting element 41R including a light emitting diode and the like is described.
Each color light emitted from 41B has extremely high color purity. Further, at least one light emitting element 41R to 41B is provided, and the light emitting elements 41R to 41B are linearly arranged along the side surface of the light guide plate 42 in a predetermined pattern. The arrangement pattern of the light emitting elements 41R to 41B and the number thereof are not limited to those shown in the drawing.

Element substrate 20 constituting liquid crystal panel 30
Is roughly configured by forming a TFD element 24, a pixel electrode 23, and the like on the surface of the basic body 21 made of a translucent material such as glass or transparent resin on the liquid crystal layer 50 side. On the other hand, the color filter substrate 10 has a semi-transmissive reflective layer 12, a color filter 13, and a scanning line (counter electrode) 15 on the surface of the substrate body 11 made of a translucent material such as glass or transparent resin on the liquid crystal layer 50 side. And are sequentially laminated to form a schematic structure.

More specifically, in the element substrate 20, a large number of data lines 22 are provided in stripes on the surface of the substrate body 21, and each data line 22 is transparent such as indium tin oxide (ITO). A large number of pixel electrodes 23 made of a conductive material are connected via TFD elements 24. When the entire surface of the element substrate 20 on the liquid crystal layer 50 side is viewed, a large number of pixel electrodes 23 are arranged in a matrix, and in the transflective liquid crystal device 1, a region in which each pixel electrode 23 is formed and its peripheral portion. Is 1 dot. In addition, each data line 22 is electrically connected to an external connection terminal (not shown) provided on at least one of the substrates via a wiring line 22a connected to one end.

An alignment film 25 for controlling the alignment of liquid crystal molecules in the liquid crystal layer 50 is formed on the outermost surface of the element substrate 20 on the liquid crystal layer 50 side. Further, in the element substrate 20, the retardation plate 26 and the polarizer 27 are sequentially attached to the surface of the substrate body 21 opposite to the liquid crystal layer 50. In FIG. 1, the alignment film 25, the retardation film 26, and the polarizer 27 are not shown.

On the other hand, in the color filter substrate 10,
The semi-transmissive reflective layer 12 is composed of a reflective layer made of aluminum, silver, silver alloy, or the like, having a slit-shaped opening 12a corresponding to each dot.
2, the opening 12a is a light transmitting portion that transmits light,
The other portion functions as a light reflecting portion that reflects light.

The color filter 13 formed on the liquid crystal layer 50 side of the semi-transmissive reflective layer 12 is a pigment dispersion type colored layer which is colored red (R), green (G) and blue (B), respectively. It is configured to include 13R, 13G, and 13B.
The colored layers 13R to 13B are provided periodically corresponding to the respective dots, and are arranged, for example, in a pattern as shown in FIG. The transflective liquid crystal device 1 has a configuration in which one pixel can be displayed with 3 dots in which the red, green, and blue colored layers 13R to 13B are formed. Further, in the color filter 13, a light shielding layer (black matrix) 13X is formed on the adjacent colored layers 13R to 13B (that is, the peripheral portions of the dots).

On the liquid crystal layer 50 side of the color filter 13, in order to protect the colored layers 13R to 13B of the color filter 13 and to flatten the surface of the substrate body 11 on which the color filter 13 is formed, An overcoat layer 14 made of a film or the like is formed. Further, the liquid crystal layer 50 side of the overcoat layer 14 extends in a direction intersecting with the extending direction of the data lines 22 of the element substrate 20,
A strip-shaped scanning line (counter electrode) 15 made of a transparent conductive material such as ITO is formed. Like the data line 22 of the element substrate 20, this scanning line 15 is also connected to one end of the lead wiring ( It is electrically connected to an external connection terminal (not shown) provided on at least one of the substrates via the (not shown).

Further, the liquid crystal layer 5 of the color filter substrate 10
An alignment film 16 for controlling the alignment of liquid crystal molecules in the liquid crystal layer 50 is formed on the 0-side outermost surface. In addition, in the color filter substrate 10, the liquid crystal layer 50 of the substrate body 11 is
The retardation plate 17 and the polarizer 18 are sequentially attached to the surface on the opposite side. In FIG. 1, the alignment film 1
6, the phase difference plate 17, and the polarizer 18 are omitted.

Further, as shown in FIG. 2, a large number of spherical spacers 51 are arranged in the liquid crystal layer 50 in order to make the substrate spacing (cell gap) between the color filter substrate 10 and the element substrate 20 uniform. Has been done.

The transflective liquid crystal device 1 of the present embodiment is configured as described above, and in a dark place where the brightness of external light is insufficient, the backlight 40 is turned on to display the transmissive mode. In a bright place where the light is bright, the backlight 40 is not turned on, and the reflection mode display can be performed using the external light.

That is, in the transmissive mode, the backlight 40 is turned on, and the light emitted from the backlight 40 is
The light enters the color filter substrate 10, passes through the opening 12a (light transmitting portion) of the semi-transmissive reflective layer 12, and passes through the color filter 1
After passing through 3 and the like, the liquid crystal layer 50 and the element substrate 20 are sequentially transmitted and emitted to the observer side, so that display can be performed, and in reflection mode, external light such as sunlight is observed. After sequentially passing through the element substrate 20 and the liquid crystal layer 50 from the user side, the color filter substrate 10 is made to enter the color filter substrate 1.
0 of the semi-transmissive reflection layer 12 is reflected by the light reflection portion (a portion where the opening 12a is not formed), and the liquid crystal layer 5 is again reflected.
0, it is possible to display by utilizing the fact that the light passes through the element substrate 20 and is emitted to the observer side.

In the transmissive mode, the light incident on the liquid crystal panel 30 is transmitted through the color filter 13 only once and is emitted to the viewer side, whereas in the reflective mode, the light incident on the liquid crystal panel 30 is transmitted. Before the reflection by the semi-transmissive reflection layer 12 and twice after the reflection, the color filter 1
After passing through 3, the light is emitted to the observer side for display.

Further, in the transflective liquid crystal device 1 of the present embodiment, liquid crystal molecules in the liquid crystal layer 50 are controlled by the alignment films 16 and 25 in a predetermined direction when no voltage is applied, as in a general liquid crystal device. On the other hand, the display is performed by utilizing the fact that the arrangement of the liquid crystal molecules changes along the vertical electric field generated between the pixel electrode 23 and the scanning line (counter electrode) 15 when the voltage is applied.

That is, "dark display" is achieved by configuring such that light emitted from the liquid crystal layer 50 to the viewer side when no voltage is applied (OFF) does not pass through the polarizer 27 on the viewer side. A "bright display" can be obtained by arranging such that light emitted from the liquid crystal layer 50 to the observer side when a voltage is applied (ON) is transmitted through the polarizer 27 on the observer side. be able to. Further, conversely, the light emitted from the liquid crystal layer 50 to the viewer side when no voltage is applied (OFF) is configured to pass through the polarizer 27 on the viewer side,
In addition to obtaining "bright display", light emitted from the liquid crystal layer 50 to the viewer side when voltage is applied (ON) is configured not to pass through the polarizer 27 on the viewer side, and "dark display" is provided. It is also possible to obtain. Hereinafter, in this specification, "bright display"
The state in the liquid crystal layer 50 at this time is called a "bright display state", and the state in the liquid crystal layer 50 at the time of "dark" display is called a "dark display state". Also, gradation display is possible by changing the voltage applied to the liquid crystal layer 50 stepwise and changing the arrangement of the liquid crystal molecules in the liquid crystal layer 50 stepwise between the bright display state and the dark display state. become. In the present specification, “when no voltage is applied” and “when voltage is applied” refer to “when the applied voltage to the liquid crystal layer is less than the threshold voltage of the liquid crystal” and “applied voltage to the liquid crystal layer”, respectively. Is greater than or equal to the threshold voltage of the liquid crystal ”.

The above is the basic display mechanism of the transflective liquid crystal device 1 of the present embodiment. Further, in the present embodiment, in the reflective mode, like a general liquid crystal device,
In contrast to normal display, in transmissive mode,
The display can be performed by field sequential driving.

That is, in the reflective mode, the liquid crystal panel 30 is driven for each frame to display one pixel in one frame, whereas in the transmissive mode, one frame is divided into three.
Divided into fields, red, green, and blue light emitting elements 41R-4
1B is lit sequentially in time, and the liquid crystal panel 30 is driven for each field in accordance with the lighting timing of each of the light emitting elements 41R to 41B to display one pixel in one frame.
The display can be performed by field sequential driving.

This will be described in detail with reference to FIGS. 3 and 4. 3 and 4 show red, green, and blue colored layers 13R to
With 3 dots with 13B formed, for each frame,
Red (R), Green (G), Blue (B), White (W), Black (BK)
3 is a timing chart for sequentially displaying
Shows a timing chart when displaying in the reflective mode, and FIG. 4 shows a timing chart when displaying in the transmissive mode. 3 and 4, the dots R,
G and B represent dots in which red, green, and blue colored layers 13R to 13B are formed, respectively. Also, as mentioned above,
Gradation display becomes possible by gradually changing the voltage applied to the liquid crystal layer 50 and gradually changing the arrangement of the liquid crystal molecules in the liquid crystal layer 50 between the bright display state and the dark display state. However, in order to simplify the description, it is assumed that the arrangement of the liquid crystal molecules in the liquid crystal layer 50 is switched between the bright display state and the dark display state to perform the display.

As shown in FIG. 3, in the reflection mode, the color image signal S is supplied to the liquid crystal panel drive circuit for each frame, and the liquid crystal panel drive circuit based on the color image signal S, the liquid crystal panel 30. The signals are independently supplied to the respective dots R to B, and the liquid crystal layers 50 of 3 dots R, G, and B on which the red, green, and blue colored layers 13R to 13B are formed are respectively set to the bright display state (L). Display is performed by switching to the dark display state (D).

For example, in one frame, by setting the liquid crystal layer 50 of the dot R to the bright display state and the liquid crystal layer 50 of the dots G and B to the dark display state, red light is emitted to the viewer side and red is displayed. can do. The same can be displayed for green and blue. Further, by setting the liquid crystal layer 50 of all the dots R to G in the bright display state in one frame, red light, green light, and blue light are emitted, and white can be displayed. Similarly, a mixed color of red and green, a mixed color of red and blue, and a mixed color of green and blue can be displayed. Further, in one frame, black can be displayed by setting the liquid crystal layer 50 of all the dots R to B in the dark display state.

On the other hand, as shown in FIG. 4, in the transparent mode, one frame is divided into three fields, and red,
The light emitting elements 41R to 41B that emit green and blue are sequentially turned on in time, and the liquid crystal panel drive circuit is caused to display red, green, and blue color image signals SR and SG in accordance with the lighting timing of each of the light emitting elements 41R to 41B. SB is supplied sequentially in time, and the liquid crystal panel drive circuit independently supplies signals to the dots RB of the liquid crystal panel 30 based on these color image signals SR to SB, and the red, green, and blue coloring layers are provided. The liquid crystal layer 50 of 3 dots R to B on which 13R to 13B are formed is displayed by switching between the bright display state (L) and the dark display state (D) in time sequence.

At this time, the light emitting elements 41R to 41B
The respective colored lights emitted by the colored layers 13R to 1R of the same color
The liquid crystal panel 30 is driven so that only the dots on which 3B is formed are transmitted. That is, in the field in which the red light emitting element 41R is turned on, only the dot displaying red is turned on, and similarly, the green (blue) light emitting element 41G (41B) is turned on.
In the field where is illuminated, the liquid crystal panel 30 is driven so that only the dots displaying green (blue) are illuminated.

For example, in a field in which the red light emitting element 41R is turned on in one frame, the liquid crystal layer 50 of the dot R is in the bright display state, the liquid crystal layer 50 of the dots G and B is in the dark display state, and the light emitting elements other than the red light are emitted. In the field that lights up, by setting the liquid crystal layer 50 of all the dots R to B in the dark display state, red light is emitted to the viewer side, and red can be displayed. The same can be displayed for green and blue.

In a field in which the red light emitting element 41R is turned on in one frame, the liquid crystal layer 5 of the dot R is formed.
In the field in which 0 is the bright display state, the liquid crystal layers 50 of the dots G and B are in the dark display state, and the green light emitting element 41G is turned on, the liquid crystal layer 50 of the dot G is in the bright display state, the dots R and B are displayed.
In the field in which the liquid crystal layer 50 of No. 4 is set to the dark display state and the blue light emitting element 41B is turned on, the liquid crystal layer 50 of the dot B is set to the bright display state and the liquid crystal layer 50 of the dots R and G is set to the dark display state for observation. Red light, green light, and blue light are emitted to the person side, and white can be displayed. Similarly, a mixed color of red and green, a mixed color of red and blue, and a mixed color of green and blue can be displayed.

Further, in one frame, all the dots R to B are generated in all the fields of turning on the red light emitting element 41R, turning on the green light emitting element 41G, and turning on the blue light emitting element 41B. It is possible to display black by setting the liquid crystal layer 50 of No. 3 to a dark display state.

As described above, the reflection mode and the transmission mode can be displayed. As described above, in the present embodiment, the light incident on the liquid crystal panel 30 is not reflected by the color filter 1.
In the reflection mode in which the liquid crystal 3 is transmitted twice and is emitted to the observer side, display is performed by normal driving, whereas the light incident on the liquid crystal panel 30 is transmitted through the color filter 13 only once and is emitted to the observer side. In the transmission mode, the three types of the light emitting elements 41R to 41B that emit color light with high color purity are sequentially turned on for time, and display is performed by field sequential driving. Therefore, according to this embodiment, it is possible to widen the color reproduction range of the display when performing the display in the transmissive mode (the color purity can be increased) without deteriorating the display quality in the reflective mode. It is possible to provide the transflective liquid crystal device 1 having excellent display quality.

Further, in this embodiment, when displaying in the transmissive mode, signals are independently supplied to the respective dots, and the respective colored lights emitted from the light emitting elements 41R to 41B are colored layers 13R to 13B of the same color. Since the liquid crystal panel 30 is driven and the display is performed so that only the dots on which the dots are formed are transmitted, the backlight 40 (light emitting elements 41R to 41R-4
1B), the color of the light emitted from the colored layer and the colors of the colored layers 13R to 13B are visually recognized in an overlapping manner, and the colored layers of other colors are not visually recognized. Therefore, the color reproduction of the display when the display is performed in the transmission mode is performed. The range can be further widened (color purity can be further increased), and higher quality display can be obtained. However, in the case of such a configuration, one frame is divided into three fields, and a signal is independently supplied to each dot of the liquid crystal panel 30 for each field, and the liquid crystal panel 3 is supplied.
Since it is necessary to drive 0, the circuit structure of the liquid crystal panel drive circuit becomes complicated.

Therefore, in order to simplify the circuit structure of the liquid crystal panel drive circuit, instead of driving the liquid crystal panel 30 by independently supplying a signal to each dot when displaying in the transmissive mode by field sequential drive. As shown in FIG. 5, the same signal may be supplied to the three dots R to B on which the colored layers 13R to 13B are formed, and the liquid crystal panel 30 may be driven for display.

That is, as shown in FIG. 5, one frame is divided into three fields, the light emitting elements 41R to 41B are lit in time sequence, and the color image signals SR to SB are supplied to the liquid crystal panel drive circuit in time sequence. Although it is common in that the liquid crystal panel 30 is driven by the liquid crystal panel 30, the liquid crystal panel drive circuit has three dots R to R in which red, green and blue colored layers 13R to 13B are formed based on the color image signals SR to SB. B
Further, it is possible to perform display by supplying the same signal and switching the liquid crystal layer 50.

In the color filter 13 of the pigment dispersion type or the like,
As shown in FIG. 11, the red colored layer 13R, the green colored layer 13G, and the blue colored layer 13B are configured to mainly transmit red light, green light, and blue light, respectively. Passes visible light of a wavelength. For example, in the light emitting diode (R) shown in FIG. 12 that emits red light, the light emitted from the light emitting diode contains most red light with a wavelength of 650 nm. The transmittance of the colored layers 13G and 13B is about 40 to 50% in the color filter shown in FIG.

Therefore, during the lighting period of the red light emitting element 41R, the three dots R in which the colored layers 13R to 13B are formed are formed.
Even if all the liquid crystal layers 50 of ~ B are in the bright display state (L),
Red light can be emitted to the viewer side. This is because red light can pass through not only the red colored layer 13R but also the green colored layer 13G and the blue colored layer 13B.

Therefore, as shown in FIG. 5, in a field in which the light emitting elements 41R (41G, 41B) are turned on in one frame, the liquid crystal layers 50 of all the dots R to B are brought into the bright display state and the other colors are displayed. In the field where the light emitting element is turned on, red (green, blue) can be displayed by setting the liquid crystal layer 50 of all the dots R to B in the dark display state. Further, in one frame, white can be displayed by setting all the dots R to B in a bright display state in all fields. Further, in one frame, black can be displayed by setting all the dots R to B in a dark display state in all fields. As described above, when displaying in the transmissive mode by the field sequential driving, the colored layers 13R to 1R
The same signal is supplied to the 3 dots RB on which 3B is formed,
Display can also be performed by driving the liquid crystal panel 30.

When such a configuration is adopted, in the field in which the light emitting element that emits light of a certain color is turned on, all the three dots R to B on which the colored layers 13R to 13B are formed are turned on and emitted by the light emitting element. The colored light emitted is mainly transmitted through the dots on which the colored layer of that color is formed,
Display is also performed by passing through the dots formed with colored layers of other colors and emitting the dots. Therefore, a signal is independently supplied to each dot of the liquid crystal panel 30, and the light emitting elements 41R to 41R
Amount of light emitted to the viewer side when displaying in the transmission mode, as compared with the case where each color light emitted by B is configured to transmit only the dots on which the colored layers of the same color are formed. Can be increased, and a brighter display can be obtained.

Further, as described above, the colored layers 13R to 13B are
When the same signal is supplied to the three dots R to B on which the liquid crystal panel 30 is formed and the liquid crystal panel 30 is driven, a signal is independently supplied to each dot of the liquid crystal panel 30, and compared with the case where the liquid crystal panel 30 is driven. Thus, the circuit structure of the liquid crystal panel drive circuit can be simplified.

However, in the case of such a configuration, in a certain field, the colors of the colored layer other than the color of the light emitted from the light-emitting element that is turned on are mixed and displayed, and therefore each dot of the liquid crystal panel 30 is displayed. Supply signals independently to
The color reproduction range of the display is narrower than in the case where the respective color lights emitted by the light emitting elements 41R to 41B are configured to be transmitted only through the dots in which the colored layers of the same color are formed. However, since the color purity of the light emitted from the light emitting elements 41R to 41B composed of light emitting diodes and the like is extremely high, the color of the colored layer other than the color of the light emitted from the lighted light emitting element is mixed in a certain field. Even if displayed, compared to the transmissive mode display of the conventional transflective liquid crystal device using a white light source, the color reproduction range is wider (higher color purity) and high quality display can be obtained. .

As described above, in this embodiment, when displaying in the transmissive mode, one frame is divided into three fields and the display is performed by field sequential driving, so that the color reproduction range of the display in the transmissive mode is wide (color It has been described that it is possible to provide the transflective liquid crystal device 1 having high purity) and excellent display quality.

In the transflective liquid crystal device 1, the liquid crystal layer 50
Display is performed by changing the arrangement of the liquid crystal molecules in the liquid crystal layer 50 by applying a voltage to the dots. When displaying in the transmissive mode by field sequential driving, signals are independently supplied to the dots R to G. When supplying and displaying as shown in FIG. 4, the same signal is supplied to 3 dots R to G,
In both cases of displaying as shown in FIG. 5, 1
Since the liquid crystal panel 30 is driven for each field, voltage application (ON) to the liquid crystal layer 50 and the liquid crystal layer 50 are performed as compared with normal display in which the liquid crystal panel is driven for each frame.
Since the number of times the voltage application to the
Power consumption increases.

Therefore, in this embodiment, it is preferable that the user can switch between the field sequential drive display and the normal drive display when the transparent mode display is performed. With such a configuration, when the user desires a wide color reproduction range (high color purity) and high quality display, display by field sequential drive can be performed,
A display of the same quality as a conventional transflective liquid crystal device will do,
When it is desired to reduce power consumption, it is possible to perform display by normal driving, which is preferable.

Here, the display mechanism for displaying by normal driving in the transmissive mode will be briefly described.
In the present embodiment, red provided in the backlight 40,
Since white light can be obtained by turning on all of the green and blue light emitting elements 41R to 41B at the same time, by turning on all the light emitting elements 41R to 41B and driving the liquid crystal panel 30 for each frame, The transmission mode can be displayed by driving. The timing chart for displaying in the transmissive mode by normal driving is exactly the same as the timing chart for displaying in the reflective mode (see FIG. 3).

As described above, in the transflective liquid crystal device 1 of this embodiment, it is possible to switch between the transmissive mode display by field sequential driving, the transmissive mode display by normal driving, and the reflective mode display by normal driving. Although it is possible, such display switching can be realized by adopting the configuration shown in FIG. 6. FIG. 6 is a functional block diagram showing an example of the internal structure of the IC mounted in the transflective liquid crystal device 1 of this embodiment.

That is, in the IC mounted in the semi-transmissive reflection type liquid crystal device 1, a field sequential color signal generation circuit 71 and a transmission mode liquid crystal panel drive circuit 72 for displaying a transmission mode by field sequential driving. And a backlight lighting circuit (illuminating means lighting circuit) 73 are mounted. Further, the IC mounted on the semi-transmissive reflection type liquid crystal device 1 has a color signal generation circuit 81 for displaying a transmissive mode by normal driving.
A transparent mode liquid crystal panel drive circuit 82 and a backlight lighting circuit 83 are mounted. Further, the IC mounted on the transflective liquid crystal device 1 includes a color signal generation circuit 91, a reflection mode liquid crystal panel drive circuit 92, and a backlight lighting circuit 93 for displaying a reflection mode. It is installed. It should be noted that all of these circuits may be mounted on one IC, or they may be mounted separately on a plurality of ICs.

Further, one color signal generation circuit control unit 60 is mounted on the IC mounted on the semi-transmissive reflection type liquid crystal device 1, and by the color signal generation circuit control unit 60,
A signal indicating which display mode is used for displaying is output. That is, the switching means 61 is provided between the color signal generation circuit control unit 60 and the field sequential color signal generation circuit 71 and the color signal generation circuits 81 and 91, and is output from the color signal generation circuit control unit 60. Based on the signal, the switching means 61 is activated to electrically connect the color signal generation circuit control unit 60 and the color signal generation circuit in the desired display mode.

When performing the transmissive mode display by field sequential driving, the color signal generation circuit control unit 60 and the field sequential color signal generation circuit 71 are connected. In the field sequential color signal generation circuit 71, the color signal generation circuit control unit 60
The color image signal SG based on the signal output by
1, vertical timing signal V _sync , horizontal timing signal H
_{The sync} is output to the transmission mode liquid crystal panel drive circuit 72, and the vertical timing signal V _sync and the horizontal timing signal H _sync are output to the backlight lighting circuit 73.

The color image signal SG1 corresponds to the color image signals SR, SG and SB shown in FIGS. 4 and 5,
One frame is divided into three fields and output. In addition, the vertical timing signal V _sync and the horizontal timing signal H
_sync is a synchronization signal for synchronizing the light emission timing of the light emitting elements 41R to 41B and the drive timing for driving the liquid crystal panel 30.

The backlight lighting circuit 73 drives the backlight 40 based on the vertical timing signal V _sync and the horizontal timing signal H _sync . That is, one frame is divided into three fields, and the light emitting element 4 of the backlight 40 is divided.
1R to 41B are lit in time sequence. Further, when the display is performed as shown in FIG. 4, the color image signal SG1,
And vertical timing signal V _sync , horizontal timing signal H
Based on _sync , the signal SG2 is input from the liquid crystal panel drive circuit 72 to the liquid crystal panel 30, and the liquid crystal panel 30 is driven. At this time, a signal is independently input to each dot of the liquid crystal panel 30.

Since the vertical timing signal V _sync and the horizontal timing signal H _sync are supplied from the field sequential color signal generation circuit 71 to both the liquid crystal panel drive circuit 72 and the backlight lighting circuit 73, the light emitting elements 41R to 41R. It is possible to synchronize the lighting timing of 41B and the output timing of the color image signal SG1 (SR to SB), and display can be performed as shown in FIG.

When the display is performed as shown in FIG. 5, the liquid crystal panel drive circuit 72 causes the liquid crystal panel 30 to move to the liquid crystal panel 30 based on the color image signal SG1, the vertical timing signal V _sync , and the horizontal timing signal H _sync. The circuit structure of the liquid crystal panel drive circuit 72 may be changed so that the input signal is changed from SG2 to SG3. In the case where the display is performed as shown in FIG. 5, the liquid crystal panel drive circuit 72 displays 3 dots R to 1 pixel of the liquid crystal panel 30.
The same signal is input to G.

On the other hand, the display in the transmissive mode by normal driving is
When performing, the color signal generation circuit control unit 60 and the color
The signal generation circuit 81 is connected, and the field sequence
Same as the case of displaying the transparent mode by the digital drive,
The display is done. That is, in the color signal generation circuit 81
Is a signal output from the color signal generation circuit controller 60
Based on the color image signal SG4, vertical timing signal
Issue V_sync, Horizontal timing signal H_syncLiquid for transmission mode
Input to the crystal panel drive circuit 82. In addition, the field
When displaying the transparent mode by sequential drive
From the color signal generation circuit to the backlight lighting circuit,
Vertical timing signal and horizontal timing signal are input
However, when displaying in transmissive mode by normal driving,
It is not necessary to turn on the light emitting elements 41R to 41B sequentially in time.
Therefore, the backlight is turned on from the color signal generation circuit 81.
The circuit 83 has a signal to turn on the backlight 40.
Vertical timing signal V_sync, Horizontal tie
Minging signal H _syncIs not entered.

Then, the backlight 40 is driven by the backlight lighting circuit 83, all the light emitting elements 41R to 41B of the backlight 40 are turned on, and white light is emitted. The color image signal SG4 output from the color signal generation circuit 81 to the liquid crystal panel drive circuit 82 corresponds to the color image signal S shown in FIG. 3 and is output for each frame. Then, based on the color image signal SG4, the vertical timing signal V _sync , and the horizontal timing signal H _sync , the signal SG5 is input from the liquid crystal panel drive circuit 83 to the liquid crystal panel 30, and the liquid crystal panel 30 is driven,
As shown in FIG. 3, the display can be performed.

On the other hand, in the case of performing the reflection mode display by the normal drive, the color signal generation circuit control unit 60 and the color signal generation circuit 91 are connected, and similarly to the case of performing the transmission mode display by the normal drive, The display is done. That is, in the color signal generation circuit 91, the color image signal SG6, the vertical timing signal V _sync , and the horizontal timing signal H _sync are supplied to the reflection mode liquid crystal panel drive circuit 92 based on the signal output from the color signal generation circuit control unit 60.
To enter. In addition, a signal that the backlight 40 is not turned on is input from the color signal generation circuit 91 to the backlight lighting circuit 83, and all the light emitting elements 41R to 41B of the backlight 40 are turned off by the backlight lighting circuit 93. Display is performed using light.

Further, the color image signal SG6 output from the color signal generation circuit 91 to the liquid crystal panel drive circuit 92.
Corresponds to the color image signal S shown in FIG. 3, and is supplied for each frame. Based on the color image signal SG6, the vertical timing signal V _sync , and the horizontal timing signal H _sync , the liquid crystal panel drive circuit 93 to the liquid crystal panel 30.
The signal SG7 is input to the liquid crystal panel 30, the liquid crystal panel 30 is driven, and the display can be performed as shown in FIG.

By adopting the above configuration, it is possible to switch between the transmission mode display by field sequential drive, the transmission mode display by normal drive, and the reflection mode display by normal drive. Note that the internal structure of the IC shown in FIG. 6 is an example, and the circuits and the like to be mounted can be designed as appropriate.

[Second Embodiment] Next, the second embodiment of the present invention will be described.
The structure of the transflective liquid crystal device of the embodiment will be described. In this embodiment, a TFT (Thin-Film Transistor)
An application example of the present invention to an active matrix type liquid crystal device using an element as a switching element will be shown. FIG. 7 is an exploded perspective view showing the overall configuration of the transflective liquid crystal device of this embodiment. Since the basic structure and display mechanism of the transflective liquid crystal device of this embodiment are the same as those of the first embodiment,
The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Also in this embodiment,
The upper side is shown as the observer side.

As shown in FIG. 7, in the transflective liquid crystal device 2 of this embodiment, a color filter substrate (lower substrate) 100 and an element substrate (which are opposed to each other with a liquid crystal layer (not shown) in between) are arranged. Liquid crystal panel 1 including an upper substrate 110
20 and a backlight 40 arranged on the side opposite to the viewing side of the liquid crystal panel 120.

The element substrate 110 is roughly constructed by forming a TFT element 114, a pixel electrode 115 and the like on the surface of the basic body 111 on the liquid crystal layer side, and forming an alignment film (not shown) on the liquid crystal layer side. There is. In addition, the color filter substrate 1
Reference numeral 00 denotes a semi-transmissive reflective layer 12, a color filter 13, an overcoat layer (not shown), a common electrode 102, and an alignment film (not shown), which are sequentially stacked on the liquid crystal layer side surface of the substrate body 101. It is made up and is roughly configured.

In this embodiment, one end of the element substrate 110 is located outside the color filter substrate 100, and an external connection terminal is provided in a portion located outside the color filter substrate 100. An IC equipped with a liquid crystal panel drive circuit etc. is electrically connected,
For simplification of the drawing, the color filter substrate 100 and the element substrate 110 are shown as having the same area, and the external connection terminals and the IC are not shown.

More specifically, in the element substrate 110,
A large number of data lines 112 and a large number of scanning lines 113 are provided in a grid pattern on the surface of the substrate body 111 so as to intersect each other. A TFT element 114 is formed near the intersection of each data line 112 and each scanning line 113, and each TF is formed.
The pixel electrode 115 is connected via the T element 114. When the entire surface of the element substrate 110 on the liquid crystal layer side is viewed, a large number of pixel electrodes 115 are arranged in a matrix, and in the transflective liquid crystal device 2, a region in which each pixel electrode 115 is formed and its peripheral portion are formed. It is 1 dot.
The data lines 112 and the scanning lines 113 are electrically connected to external connection terminals (not shown) provided on the element substrate 110 via the lead-out wirings 112a and 113a connected to one ends of the data lines 112 and the scanning lines 113, respectively. ing.

Further, in the color filter substrate 100, a common electrode 102 is formed on substantially the entire surface of the color filter substrate 100 instead of the scanning line (counter electrode) of the first embodiment, and the common electrode 102 is the element substrate. It is electrically connected to an external connection terminal (not shown) provided at 110.

As described above, the present invention can be applied to an active matrix type transflective liquid crystal device using a TFT element, and the same effect as that of the first embodiment can be obtained. That is, in the reflection mode in which the light incident on the liquid crystal panel 120 is transmitted through the color filter 13 twice and is emitted to the observer side, display is performed by normal driving, whereas the light incident on the liquid crystal panel 120 is performed.
In the transmissive mode in which the light is transmitted only once through 3 and is emitted to the observer side, three types of light emitting elements 4 that emit color light with high color purity
By turning on 1R to 41B sequentially in time and performing display by field sequential driving, it is possible to widen the color reproduction range of display when performing display in the transmissive mode without degrading the display quality in the reflective mode. It is possible to provide the semi-transmissive reflective liquid crystal device 2 (which can increase color purity) and has excellent display quality.

In the first and second embodiments, the element substrate is arranged on the viewing side and the color filter substrate is arranged on the backlight side. However, the present invention is not limited to this, and By providing a semi-transmissive reflective layer on the liquid crystal layer side surface of the substrate located on the opposite side to the side, and arranging the color filter on the visible side of the semi-transmissive reflective layer, the color filter substrate is disposed on the visible side, Even if the substrate is arranged on the backlight side, the same display can be performed.

Further, in the first and second embodiments, the transflective liquid crystal device having the transflective layer formed of the reflective layer having the opening is taken up and described, but the present invention is not limited to this. However, it can be formed by thinly forming a light-reflecting material, and the whole thereof includes a transflective layer that functions as a transmissive portion that transmits light and a reflective portion that reflects light. It can also be applied to a transflective liquid crystal device.

Further, in the first and second embodiments, a TFT element or a TF is used as the switching element.
Although the active matrix type liquid crystal device using the D element has been described above, the present invention is not limited to this, and can be applied to any driving type liquid crystal device such as a passive matrix type liquid crystal device. However, when performing the transmission mode display by the field sequential drive, it is necessary to increase the response speed of the liquid crystal as compared with the case of performing the reflection mode display by the normal drive or the transmission mode display by the normal drive. It is particularly suitable to be applied to an active matrix type liquid crystal device capable of increasing the response speed of liquid crystal.

[Electronic Equipment] Next, specific examples of electronic equipment including the transflective liquid crystal device 1 or 2 of the first and second embodiments of the present invention will be described. FIG. 8A is a perspective view showing an example of a mobile phone. In FIG. 8A, reference numeral 500 denotes a mobile phone main body, and 501 denotes a liquid crystal display unit including the transflective liquid crystal device 1 or 2. FIG. 8B is a perspective view showing an example of a portable information processing device such as a word processor and a personal computer. Figure 8 (b)
In FIG. 6, reference numeral 600 denotes an information processing device, 601 denotes an input unit such as a keyboard, 603 denotes an information processing main body, and 602 denotes a liquid crystal display unit including the transflective liquid crystal device 1 or 2. FIG. 8C is a perspective view showing an example of a wrist watch type electronic device. In FIG. 8C, 700 indicates a watch body, and 701 indicates a liquid crystal display unit including the transflective liquid crystal device 1 or 2. 8 (a)-
Since the electronic device shown in (c) includes the transflective liquid crystal device 1 or 2 of the above-described embodiment, it has a wide color reproduction range when displaying in the transmissive mode and is excellent in display quality. Becomes

[0097]

EXAMPLES Next, examples according to the present invention and conventional examples will be described. Example 1 A semi-transmissive reflective liquid crystal device of the present invention according to the first embodiment was manufactured, and a transmissive mode was displayed by field sequential driving. A light emitting diode was used as the light emitting element. Also, as shown in FIG.
A signal was independently supplied to each dot so that each color light emitted from the light emitting element was transmitted only through the colored layer of that color for display.

Example 2 A semi-transmissive reflective liquid crystal device of the present invention according to the first embodiment was manufactured, and a transmissive mode was displayed by field sequential driving. A light emitting diode was used as the light emitting element. Further, as shown in FIG. 5, the same signal was supplied to 3 dots on which red, green, and blue colored layers were formed for display.

(Conventional Example) A conventional transflective liquid crystal device using a light emitting diode that emits white light was manufactured as a light source of a backlight, and a transmissive mode display was performed by normal driving. The structure was the same as in Examples 1 and 2 except for the light source of the backlight and the internal structure of the IC.

(Evaluation) Chromaticity based on XYZ color system of CIE standard color system when displaying red, green and blue in Examples 1 and 2 and conventional example using a spectroscope. Was measured. In the chromaticity based on the XYZ color system of the CIE standard color system, the larger the value of the x coordinate, the higher the purity of red, and the larger the value of the y coordinate, the higher the purity of green. The smaller the both values, the higher the blue purity.

(Result) In the conventional example, the chromaticity when displaying red, green, and blue is R (0.387, 0.32), respectively.
6), G (0.331, 0.367), B (0.23)
0, 0.260). On the other hand, in Example 1, the chromaticity when displaying red, green, and blue is R respectively.
(0.601, 0.320), G (0.310, 0.5)
50), B (0.161, 0.165), and in Example 2, the chromaticity when displaying red, green, and blue is R (0.
520, 0.330), G (0.321, 0.43)
6) and B (0.205, 0.200).

FIG. 9 also shows the chromaticities when displaying red, green, and blue in the conventional example and the first example. Further, in the conventional example and the second example, the chromaticities when red, green, and blue are displayed are also shown in FIG. 9 and 10, red,
The area of the triangle connecting the chromaticities when displaying green and blue is the color reproduction range. As shown in FIGS. 9 and 10, the color reproduction range of the display in Example 2 in which the same signal was supplied to the three dots on which the red, green, and blue colored layers were formed for display was independent for each dot. Is narrower than the display in Example 1 in which each color light emitted from the light emitting element is supplied so as to transmit only the colored layer of that color, but the display in Examples 1 and 2 is The color reproduction range is twice as wide as that of the conventional example, and three types of light emitting elements capable of emitting red light, green light, and blue light are used as the light source of the backlight, and field sequential driving is performed. It has been found that the display in the transmissive mode can provide a display with a wide color reproduction range (high color purity).

[0103]

As described above in detail, according to the present invention, as the light source of the illuminating means (backlight), color lights corresponding to the colors of the plurality of types of colored layers forming the color filter are emitted. Since it is configured to display in transmissive mode by field-sequential drive using multiple types of light-emitting elements that can be used, a semi-transmissive reflective type with a wide color reproduction range when displaying in transmissive mode and excellent display quality A liquid crystal device can be provided. Further, by including the semi-liquid crystal device of the present invention, it is possible to provide an electronic device having a wide color reproduction range when displaying in a transmission mode and excellent in display quality.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an overall configuration of a transflective liquid crystal device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the transflective liquid crystal device according to the first embodiment of the present invention.

FIG. 3 is a timing chart for explaining a display mechanism of the transflective liquid crystal device according to the first embodiment of the invention.

FIG. 4 is a timing chart for explaining a display mechanism of the transflective liquid crystal device according to the first embodiment of the invention.

FIG. 5 is a timing chart for explaining the display mechanism of the transflective liquid crystal device according to the first embodiment of the present invention.

FIG. 6 is a functional block diagram showing an internal structure of an IC mounted in the transflective liquid crystal device according to the first embodiment of the present invention.

FIG. 7 is an exploded perspective view showing an overall configuration of a semi-transmissive reflective liquid crystal device according to a second embodiment of the present invention.

FIG. 8A is a diagram showing an example of a mobile phone provided with the transflective liquid crystal device of the above embodiment, and FIG. 8B.
FIG. 8 is a diagram showing an example of a portable information processing device including the transflective liquid crystal device of the above embodiment, and FIG. 8C is a wrist watch type electronic device including the transflective liquid crystal device of the above embodiment. It is a figure which shows an example.

FIG. 9 is a diagram showing a conventional example and a red color in Example 1;
It is a figure which also shows chromaticity when displaying green and blue.

FIG. 10 shows a conventional example and a second example.
It is a figure which shows together chromaticity when displaying red, green, and blue.

FIG. 11 is a diagram showing an example of spectral characteristics of each colored layer of a pigment dispersion type color filter.

FIG. 12 is a diagram showing an example of the relationship between the wavelength of light emitted from a light emitting diode that emits red light, green light, and blue light and the relative emission intensity.

[Explanation of symbols]

1, 2 transflective liquid crystal device (liquid crystal device) 30, 120 liquid crystal panel 10, 100 color filter substrate 20, 110 element substrate 11, 21, 101, 111 substrate body 12 transflective layer 13 color filter 13R, 13G, 13B Coloring layer 13X Light-shielding layer 40 Backlight (illuminating means) 41R, 41G, 41B Light emitting element 42 Light guide plate 50 Liquid crystal layer 71 Field sequential color signal generation circuit 81, 91 Color signal generation circuit 72, 82, 92 Liquid crystal panel drive circuit 73 , 83, 93 Backlight lighting circuit (illuminating means lighting circuit) 60 Color signal generation circuit control unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 641 G09G 3/20 641E 5C060 642 642L 5C080 3/34 3/34 J H04N 5/66 102 H04N 5/66 102A 102B 9/30 9/30 9/30 F term (reference) 2H048 BA02 BA45 BB01 BB03 BB08 BB10 BB42 2H091 FA02Y FA14Y FA35Y FA45Z GA11 GA13 KA10 LA15 LA16 LA30 2H093 NA43 NA43 NA65 NC16 NC34 NC43 ND08 ND08 ND16 ND08 ND17 ND17 ND08 ND17 ND08 ND08 ND08 ND08 ND08 ND08 ND08 ND17 BB28 BB29 EA01 FA56 5C058 AA07 AA08 AA09 AA10 AB02 AB03 AB04 AB05 BA01 BA26 BA29 BB03 BB23 5C060 AA07 BA03 BA04 BA09 BC01 DA02 DA07 DB13 HB07 HC16 JA18 5C080 AA10 BB05 CC03 DD03 EE30 JJ11 FF11 JJ02 JJ02

Claims (10)

[Claims] 1. A semi-transmissive reflective layer is formed on a surface of the substrate facing the liquid crystal layer of one of a pair of substrates which are opposed to each other with a liquid crystal layer interposed therebetween, and a color filter is provided on a viewing side of the semi-transmissive reflective layer. In a liquid crystal device comprising a liquid crystal panel comprising: and a lighting means arranged on the side opposite to the viewing side of the liquid crystal panel, wherein display is performed by switching between a transmissive mode and a reflective mode, A plurality of different types of colored layers are provided, and the illumination means is provided with a plurality of types of light emitting elements capable of emitting colored lights corresponding to the colors of the plurality of types of colored layers, respectively, and a transmissive mode display is provided. In doing so, one frame is divided into a plurality of fields, and the plurality of types of light emitting elements of the illumination means are made to sequentially emit light within one frame, and at the same time as the light emission timing of the light emitting elements. Thereby, the liquid crystal panel is driven for each field, the liquid crystal device and performing display by a field sequential driving. 2. Each of the colored layers forming the color filter is provided corresponding to each dot of the liquid crystal panel, and a plurality of dots formed with the plurality of types of colored layers display one pixel. When displaying in a transmissive mode by the field sequential drive, by supplying a signal to each dot of the liquid crystal panel independently, each colored light emitted by each light emitting element forms a colored layer of the same color. The liquid crystal device according to claim 1, wherein the liquid crystal panel is driven so that only the dots are transmitted. 3. Each colored layer constituting the color filter is provided corresponding to each dot of the liquid crystal panel, and one pixel is displayed by a plurality of dots formed with the plurality of types of colored layers. The liquid crystal panel according to claim 1, wherein the liquid crystal panel is driven by supplying the same signal to the plurality of dots for displaying one pixel when displaying in the transmissive mode by the field sequential drive. apparatus. 4. A color image signal corresponding to a color of light emitted from the light emitting element, a light emission timing of the light emitting element, and the light emission timing of the light emitting element for each field when displaying the transmission mode by the field sequential driving. A field sequential color signal generation circuit that generates a synchronization signal for synchronizing the drive timing for driving the liquid crystal panel, based on the color image signal and the synchronization signal generated by the field sequential color signal generation circuit, It further comprises a liquid crystal panel drive circuit for driving the liquid crystal panel, and a lighting means lighting circuit for driving the lighting means based on the synchronization signal generated by the field sequential color signal generation circuit. Described in any one of claim 1 to claim 3. Liquid crystal device. 5. Each colored layer constituting the color filter is provided corresponding to each dot of the liquid crystal panel, and a plurality of dots formed with the plurality of types of colored layers display one pixel. 5. The liquid crystal device according to claim 4, wherein the liquid crystal panel drive circuit is configured to supply a signal to each dot of the liquid crystal panel independently. 6. Each colored layer constituting the color filter is provided corresponding to each dot of the liquid crystal panel, and a plurality of dots formed with the plurality of types of colored layers display one pixel. 5. The liquid crystal device according to claim 4, wherein the liquid crystal panel drive circuit is configured to supply the same signal to the plurality of dots which display one pixel of the liquid crystal panel. 7. When performing a display in a transmissive mode, the display by the field sequential driving and all or a plurality of the plurality of types of light emitting elements are simultaneously turned on to emit white light, and for each frame, The liquid crystal device according to any one of claims 1 to 6, wherein display can be switched between normal drive for driving the liquid crystal panel. 8. The light-emitting element of the plurality of types is a light-emitting element of three types that emits red light, green light, and blue light, according to any one of claims 1 to 7. The liquid crystal device described. 9. The liquid crystal device according to claim 1, wherein the light emitting element is a light emitting diode. 10. An electronic apparatus comprising the liquid crystal device according to claim 1. Description: