JP2006072110A - Liquid crystal display device and portable electronic appliance equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which a planar area being the outside of the display arera of a liquid crystal panel is minimized, and also to provide a portable electronic appliance equipped with the liquid crystal display device. <P>SOLUTION: The liquid crystal display device 1 of the portable electronic appliance 2 is equipped with a transmissive liquid crystal display panel 10 and the backlight 20. The backlight 20 has: a light guide plate 30 equipped with a first principal surface 33 opposite to the liquid crystal display panel 10 and a second principal surface 31 on the opposite side of the first principal surface 33; and a light source 50 arranged within a range of the display region D of the liquid crystal display panel 10 on the side of the second principal surface 31 of the light guide plate 30. At least one out of the liquid crystal display panel 10 and the backlight 20 has a low transmission part 40 in a high intensity region with high intensity of light from the light source 50 located within a range of the display region D of the liquid crystal display panel 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device including a transmissive liquid crystal panel and a backlight, and more particularly, a liquid crystal display device suitable for use in a portable electronic device and a portable type including the same. Related to electronic equipment.

  It is known to use a light emitting diode (LED) and a light guide plate as a backlight for illuminating a transmissive liquid crystal display panel from the back side (for example, Patent Document 1 and Patent Document 2). In these patent documents, the LED is arranged outside the display area of the liquid crystal display panel in order to increase the utilization efficiency of the light from the LED while avoiding that the high-intensity light near the LED directly reaches the eyes of the user. The liquid crystal display panel is illuminated from the back side by the light that has entered the light guide plate from the LED and has reached the range of the display area of the liquid crystal display panel.

As a result, it is difficult to avoid that the backlight including the LED and the light guide plate has a larger planar spread than the liquid crystal display panel, and the liquid crystal display device including the backlight is considerably compared with the display area of the liquid crystal display panel. It's hard to avoid getting bigger. .
JP 2004-31180 A JP 2002-109942 A

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a liquid crystal display device that can be suppressed to a planar expansion beyond the display area of a liquid crystal panel to a minimum, and a portable electronic device including the same. Is to provide.

  The liquid crystal display device of the present invention is a liquid crystal display device comprising a transmissive liquid crystal display panel and a backlight thereof in order to achieve the above object, wherein the backlight faces the liquid crystal display panel. And a light guide plate having a second main surface opposite to the first main surface, and a light source disposed on the second main surface side of the light guide plate within the display area of the liquid crystal display panel; And at least one of the liquid crystal display panel and the backlight has a low light-transmitting portion in a high-intensity region located within the display region of the liquid crystal display panel and having high light intensity from the light source.

  In the liquid crystal display device of the present invention, “the light source is disposed on the second main surface side of the light guide plate within the range of the display area of the liquid crystal display panel”, so that the light guide plate exceeds the display area of the liquid crystal display panel. Not only does it need to have a flat spread, but also the light source does not need to be arranged outside the outer periphery of the light guide plate, so the flat spread of the backlight comprising the light guide plate and the light source can be minimized. The planar size of the device can be minimized. Further, in the liquid crystal display device of the present invention, “at least one of the liquid crystal display panel and the backlight is positioned within the display area of the liquid crystal display panel, and the light intensity from the light source is low. Because it has a light-emitting part, even if the light source is within the range of the display area of the liquid crystal display panel, it gives an uncomfortable feeling that a part of the liquid crystal display panel is unnecessarily brightly illuminated by the high-intensity light from the light source. There is little fear.

  The first main surface of the light guide plate is a light exit surface, and the second main surface is typically a reflective light guide surface, which is the first main surface of the light guide plate. In order to make the intensity of light emitted from the surface uniform as much as possible, typically, it has a concavo-convex pattern made of an inclined surface that reflects light obliquely. The reflective light guide surface may include a reflective layer on the uneven surface. In addition, as long as the 1st main surface works as a light-projection surface, if desired, the uneven | corrugated pattern which consists of an inclined surface may be formed also in the 1st main surface.

  Although the low light-transmitting portion is typically formed on the light guide plate itself, if desired, a separate low light-transmitting film or plate is formed even if the low light transmitting portion is formed on the liquid crystal display panel itself. It may be inserted.

  When the low light-transmitting portion is formed on the light guide plate, the entire second main surface of the light guide plate may extend in a flat shape, and the low light-transmitting portion may be formed on a part of the outer flat surface main surface. Typically, the light guide plate includes a recess in the range of the display area of the liquid crystal display panel in the second main surface, and the low light-transmitting portion is formed on the bottom surface of the recess. In that case, the light source is disposed in the recess. In this case, the light from the light source is directly transmitted through the light guide plate in the thickness direction of the light guide plate, and an excessively bright region due to high-intensity light in the vicinity of the light source is generated on the front side of the light source. Not only can be avoided by the low light-transmitting part on the bottom surface of the recess, but also light from the light source efficiently enters the light guide plate through the side surface or peripheral surface of the recess, so the light source with the low light-transmitting part Light from the light source is likely to be effectively propagated to the entire region of the light guide plate other than the vicinity region.

  When the low light transmissive part is formed on the light guide plate itself, the low light transmissive part is composed of at least one layer selected from the group consisting of a reflective layer, a diffuse transmission layer, and a color filter layer.

  In the case where the low light-transmitting part is formed of a separate low light-transmitting film, the low light-transmitting part region may be a reflection plate, a diffusion transmission plate, or a color filter plate.

  The low light-transmitting portion typically includes one or a plurality of light-transmitting patterns, although the entire region may be low light-transmitting.

  In this case, since relatively high intensity light is transmitted from the translucent pattern, the pattern can be visually recognized with a luminance different from that of the other display portions. When a plurality of translucent patterns are provided, typically, the translucency of the portion of the liquid crystal display panel that faces each of the plurality of translucent patterns is individually controlled. The Accordingly, a part of the plurality of translucent patterns can be selectively displayed with high luminance. It should be noted that the liquid crystal display panel may be configured to be controlled so that a portion facing at least one of the plurality of translucent patterns is displayed in color.

  For example, when the liquid crystal display device is a wristwatch display device, the plurality of display patterns may include a pattern indicating a daytime and a night, and a display mode such as a plurality of clock operations or inputs (for example, a normal clock display). (TIME), alarm (ALARM), timer (TIMER), stopwatch (CHRONO)) or other patterns may be used.

  In addition to or in addition to the low light-transmitting portion formed on the light guide plate or provided by a separate low light-transmitting member, the liquid crystal display panel has a low light-transmitting property in the high-intensity region of light from the light source. You may have a part. In that case, for example, the low light-transmitting part of the liquid crystal display panel may be configured to be controlled to be negatively displayed. For negative display, the voltage of the region may be controlled separately from the other regions, but the polarization direction of the polarizing plate in the region is different from the polarization direction of the polarizing plate in the other region (typically May be rotated 90 degrees).

  The light source is typically a point light source having an intensity distribution such that the intensity in the vicinity of the light source is much higher than the intensity in other regions, typically a solid-state light emitting element, and more typically Consists of a light emitting diode (LED). However, any light source may be used as long as it is not a so-called surface light source but a so-called point light source.

  The liquid crystal display device as described above is typically provided in a portable electronic device. However, as long as it is used as an electronic device of a kind desired to minimize the planar size, typically as a small display device, it may be used for a non-portable device. The portable electronic device typically has a clock function, and may be an arm-mounted electronic device such as a wristwatch, for example.

  Next, a preferred embodiment of the present invention will be described based on a preferred example shown in the accompanying drawings.

  FIG. 1 shows a part of an electronic timepiece 2 in the form of an arm-mounted electronic device (here, a wristwatch) as a portable electronic device provided with a liquid crystal display device 1 according to a preferred embodiment of the present invention. .

  The electronic timepiece 2 includes a case 3, and a glass (transparent plate) 5 made of a glass plate or an acrylic resin plate is fitted to the outside or front side of the inward flange portion 4 of the case 3. In the chamber 6 of the case 3, a circuit board 7 on which various electric / electronic circuit components that are powered and operated by a battery (not shown) are mounted is arranged. The transmissive liquid crystal panel 10 and its backlight 20 are disposed on the front side of the.

  The transmissive liquid crystal display panel 10 includes glass plates 11 and 12 and polarizing plates 13 and 14 in which respective electrodes (not shown) are formed on opposing surfaces sandwiching a liquid crystal layer (not shown). A display voltage signal is applied to the electrodes of the glass plates 11 and 12 from the circuit board 7 via a cable (not shown).

  In the example of FIG. 1, the liquid crystal display panel 10 has a rectangular planar shape as indicated by a solid line L in (b), and a rectangular display region D indicated by a broken line is included in the range of the outer shape L. Have.

  The backlight 20 is disposed between the front surface 8 of the circuit board 7 and the back surface 15 of the liquid crystal display panel 10 and has a flat light guide plate 30 as a whole and a light emitting diode (LED) 50 as a light source.

  The light guide plate 30 includes a reflective light guide layer or region 32 that functions as a reflective surface and a light guide surface in substantially the entire region of a back surface 31 as a second main surface, and a front surface 33 as a first main surface is provided. It is a light transmission surface. The reflective light guide region 32 typically has a concavo-convex pattern made of an inclined surface that reflects light obliquely so that the intensity of light emitted from the front surface 33 is made as uniform as possible. In addition, the reflective light guide area | region 32 may be provided with the reflective surface thin layer in the outer surface. However, when sufficient reflection (including total reflection) is obtained, the reflective thin surface layer is not necessary. A diffusion transmission layer is formed on the front surface 33 so as to make the light emission intensity from the region 33b as uniform as possible over substantially the entire region or substantially the entire region 33b other than the front surface 33a of the concave portion 35 described later. It may be. The thin reflective surface layer and the diffuse transmission layer may be a thin layer formed on the surface of the light guide plate 30 by a thin film forming technique, or may be formed separately and bonded to the surface of the light guide plate 30. As can be seen from FIG. 1B, the light guide plate 30 has a rectangular planar shape extending over a range T larger than the display region D of the liquid crystal display panel 10. However, the expansion region T of the light guide plate 30 may coincide with the display region D.

  The light guide plate 30 further has a circular shape with a radius R, that is, a cylindrical shape, in a region of the rear surface 31 that overlaps (faces) the display region D of the liquid crystal display panel 10 in the plan view of FIG. The LED 50 is mounted on the surface 8 of the substrate 7 so as to have a recess 35 and to be positioned at the center of the recess 35 as seen in the plan view. The surface of the main substrate 7 in the form of a circuit block and the back surface 31 of the light guide plate 30 may be in contact with each other as illustrated or may be separated to some extent. When the distance between the two is relatively large, a pedestal may be provided on the surface of the main board 7 so that the LED 50 can be positioned in the recess 35, and the main body light emitting part of the LED 50 may be disposed on the pedestal. The region of radius R of the recess 35 corresponds to a high intensity region where the intensity B of light from the LED 50 is strong, as will be described later. The height or depth of the recess 35 is typically a little larger than the height of the LED 50. Instead of forming the recess 35 directly on the planar back surface 31, a projection that protrudes rearward from the back surface 31 may be formed on the planar back surface 31, and the recess may be formed on the projection.

  A circular reflecting layer 40 having a radius R as a low light-transmitting portion is formed on a circular bottom surface (front surface) 36 having a radius R of the recess 35. The reflecting layer 40 has, for example, (a) in FIG. Or translucent patterns 41a and 41b as shown in (c) (when not distinguished from each other or collectively referred to as "41") or 42a, 42b, 42c and 42d (when not distinguished from each other or generically) Are represented by reference numeral "42"). Each of the two translucent patterns 41a and 41b in FIG. 3A is a pattern in which a pattern of the sun and the moon indicating daytime or nighttime is indicated by a translucent and wide line. On the other hand, the four translucent patterns 42 in FIG. 3C are in the character pattern 42a (TIME) representing the normal clock display, the alarm time setting mode or the operation mode (setting state) in order from the top. Character pattern 42b (ALARM), character pattern 42c (TIMER) indicating that the timer is in the setting mode or operation mode (setting state), and character pattern 42d (CHRONO) indicating that the operation mode is a stopwatch). It is a pattern indicated by translucent and wide lines.

  In addition, the low translucency part 40 may be other things, such as a diffuse transmission layer and a color filter layer, instead of a reflection layer.

  Of the light emitted from the LED 50 located in the concave portion 35, the light toward the bottom surface 36 of the concave portion 35 is reflected by the reflective layer 40 in portions other than the patterns and characters forming the translucent patterns 41 and 42. It should be noted that in order to minimize the light emitted from the LED 50 and reflected by the reflective layer 40 from being absorbed by the surface of the substrate 7 in the recess 35, the region 7 a of the surface of the substrate 7 that is located in the recess 35. The entire surface may be a mirror surface. Here, you may consider that the electrode terminal part which concerns on mounting to the board | substrate 7 of LED50 is equivalent to a mirror surface.

  Of the light that goes directly from the LED 50 to the liquid crystal display panel 10, the light that enters the translucent line pattern 42 enters the light guide plate 30 in a relatively high intensity state and is transmitted almost straight through the light guide plate 30. The light is emitted from the facing region 33a of the front surface 33.

  The peripheral surface 37 of the recess 35 is a light transmissive surface. Accordingly, light that enters the peripheral surface 37 of the recess 35 from the LED 50 enters the light guide plate 30 from the peripheral surface 37 and is guided by the reflective light guide layer 32 of the light guide plate 30 to extend in the direction of the light guide plate 30. , The light is emitted from the surface 33 of the light guide plate 30 and enters the facing portion of the liquid crystal display panel 10. As a result, the liquid crystal display panel 10 is illuminated from the back side with an appropriate luminance that is relatively uniform and lower than the translucent pattern 42.

  When the expansion of the reflective layer 40 is small compared to the distance or distance between the reflective layer 40 on the bottom surface 36 of the recess 35 and the opposing surface 51 of the LED 50, relatively high intensity light from the LED 50 toward the liquid crystal display panel 10. In order to avoid directly entering the light guide plate 30 at places other than the translucent pattern 42, a region close to the bottom surface 36 of the peripheral surface 37 of the recess 35 may be covered with a reflective layer similar to the reflective layer 40.

  Here, even if the reflective layer 40 is a reflective thin plate or foil disposed and fixed to the bottom surface (front surface) 36 of the recess 35, a metal film or white non-coated film formed on the bottom surface 36 by the thin film formation technique is used. It may be a thin layer such as a metal thin film.

  The peripheral surface 37 of the recess 35 is formed so that the light emitted from the LED 50 can easily enter the light guide plate 30 through the peripheral surface 37. Accordingly, depending on the shape of the LED 50 and the direction dependency of the light emission intensity, the planar shape may be another shape such as an ellipse instead of a circle. Note that an antireflection layer (film) or the like is typically formed on the peripheral surface 37 in order to minimize reflection on the peripheral surface 37.

  The liquid crystal display panel 10 is display-controlled by a display control unit 16 mounted on the main board 7. In particular, the display control unit 16 is located in a portion D35 facing the recess 35 in the display region D of the liquid crystal display panel 10, and the translucency of each region D41 or D42 facing the translucent pattern 41 or 42. The high-intensity area display control unit 17 that controls Of course, the difference between the control units 16 and 17 may be a program or data difference processed by the display control circuit or the like.

  When the reflective layer 40 has translucent patterns 41a and 41b as shown in FIG. 3A, as shown in FIG. 3B, the patterns 41a and 41b in the liquid crystal display panel 10 are used. The translucency of the regions D41a and D41b overlapping each other is controlled by the high luminance region display control unit 17, and one of the regions D41a and D41b becomes translucent and the other becomes light-shielding according to the time zone. As controlled. As a result, in the region D35, the sun-shaped translucent pattern 41a or the moon-shaped translucent pattern 41b is selectively displayed with high luminance according to the time zone.

  On the other hand, when the reflective layer 40 has translucent patterns 42a, 42b, 42c, and 42d as shown in FIG. 3C, the reflective layer 40 overlaps the patterns 42a, 42b, 42c, and 42d in the liquid crystal display panel 10. The translucency of each of the areas D42a, D42b, D42c, and D42d ((d) in FIG. 3) is controlled by the high-brightness area display control unit 17, and the areas D42a, D42b, D42c, Control is performed such that any one or a plurality of D42d is selectively light-transmitting and the rest is light-blocking. As a result, in the region D35, the translucent pattern 42 of one or more of the TIME 42a, the ALARM 42b, the TIMER 42c, and the CHRONO 42d is selectively displayed with high luminance according to the operation mode and the setting state.

  Next, the display of the liquid crystal display device 1 of the electronic timepiece 2 in the form of a wristwatch configured as described above will be further described with reference to FIG.

As shown in FIG. 2B, the LED 50 basically has an intensity distribution in which the intensity B reaches the maximum B _max on the front surface, and the intensity B decreases with increasing distance from the front surface. That is, the LED 50 originally has an intensity distribution represented by a broken line S1 and solid lines P and P on both sides in FIG. 2B (here, the horizontal axis is the extended surface of the light guide plate 30 of the timepiece 2). The position Q is assumed to be a position where the central portion of the LED is located, and a position farther from the LED 50 as it moves further left and right from the position Q). When the light emitted from the LED 50 propagates through the light guide plate 30, the light is roughly S1 and P depending on the distance r from the LED 50 if the light intensity uniformizing effect by the light guide plate 30 is ignored. As shown, it has a varying intensity distribution.

  More specifically, as represented by the dashed curve S1, the strength is strong at the position Q where the LED 50 is centered and the range where the LED 50 itself is spread, and the distance is greater if the range of the LED 50 itself is exceeded even near the position Q. At the same time, the intensity sharply decreases, and when the distance r is more than the distance r = R from the position Q, the intensity fluctuation accompanying the increase of the distance r is relatively small as represented by the curve P. That is, the range where the distance r from the position Q is equal to or less than R is a high intensity region, and as shown in FIG. 2A, the radii R1, R2, R3 centered on the central position Q of the LED 50 Light intensity B1, B2, B3, B4, B5 (B3, B4 are not shown) at arcs E1, E2, E3, E4, E5 of R4, R5 (where R <R1 <R2 <R3 <R4 <R5) 1) is much smaller than the light intensity B in the high-intensity region within the radius R range, and its variation is small within the display region D. In addition, the light guide plate 30 serves to make the light from the LEDs 50 uniform so that the light intensity distribution in the region of r ≧ R can be regarded as substantially constant. As a result, the area other than the high intensity area in the display area D is roughly regarded as B1 to B2 to B3 to B4 to B5.

  Accordingly, in the display area of the liquid crystal panel 10 that is within the display area D and that is separated from the center Q of the LED 50 by a radius R or more, the LED 50 and the light guide plate 30 illuminate the display area with substantially uniform luminance. It functions as the light 20.

  In the above description, the intensity distribution is assumed to be circular. However, depending on the shape of the light source 50 and the light emission characteristics, it may be better to approximate it with another shape such as an ellipse at a position relatively close to the light source 50. In that case, the recess 35 may also be oval instead of circular.

  On the other hand, when the high-intensity light as represented by the broken line S1 enters the liquid crystal display panel 10 directly through the region of the light guide plate 30 in front of the LED 50 and passes through the panel 10, the liquid crystal display panel 10 is in the region. It is hard to avoid that the display is excessively lit and the display becomes extremely difficult to see.

  However, in the liquid crystal display device 1, the circular reflecting layer 40 having the radius R is formed on the circular bottom surface 36 having the radius R of the recess 35. The area of radius R corresponds to the intensity area indicated by the broken line S1 in FIG. In other words, the size and shape of the bottom surface 36 of the recess 35, that is, the reflective layer 40, is selected so as to hide the high intensity region and the large intensity change region in the vicinity of the center position Q in the intensity distribution composed of S 1 and P. Is done. As a result, in the liquid crystal display device 1, as shown schematically by the solid lines S 2 p, S 2, S 2 p in FIG. Except for, there is no high-intensity region S1 (or a region corresponding thereto). Therefore, in the portions other than the light-transmitting patterns 41 and 42, the intensity distribution of the light viewed on the front side of the liquid crystal display panel 1 is qualitatively substantially the same as the intensity defined by the solid lines S2, Sp, P. Follow the distribution. That is, there is no wide high-strength region on the front side of the liquid crystal display panel 1, and an easy-to-see liquid crystal display can be obtained.

  On the other hand, the translucent pattern 41 or 42 is formed on the reflective layer 40 as described above. For example, when the translucent pattern is composed of the translucent pattern characters 42 of the mode display shown in FIG. 3C, each character pattern 42a, 42b, 42c, 42d is represented by the broken line S1 in FIG. The high-intensity light is transmitted through the reflecting plate 40 through the light-transmitting portions 42a, 42b, 42c, and 42d in the form of thin lines, and the corresponding display area D42a of the liquid crystal display panel 10 is received. , D42b, D42c, D42d.

  In the normal hand movement mode of the timepiece 2, if only timepiece display is performed, control is performed so that only the region D42a of the liquid crystal display panel 10 is translucent and the other regions 42b, 42c, and 42d are non-translucent. The display is controlled by the unit 17. As a result, the high-intensity light from the LED 50 passes through the transparent portion D42a of the LED 50 after passing through the “TIME” linear transparent portion of the character pattern 42a, and is viewed from the front. Since this transmitted light has a high intensity, it is more conspicuous than the display in other parts of the display area D of the liquid crystal display panel 10 and can be easily visually recognized. On the other hand, since the high-intensity light is transmitted through the thin linear transparent portion, the high-intensity light is a narrow linear shape, and it can be avoided that the overall intensity is excessive.

  For example, when a push button switch (not shown, the same applies below) protruding from the outer peripheral surface of the case 3 is pressed to set the alarm time and enter the hand movement mode in the alarm enabled state, for example, a liquid crystal display Display control is performed by the control unit 17 so that the regions 42a and 42b of the panel 10 are translucent and the other regions 42c and 42d are non-translucent. As a result, the high-intensity light from the LED 50 passes through the transparent portions D42a and D42b of the LED 50 after passing through the “TIME” and “ALARM” linear transparent portions of the character patterns 42a and 42b, and from the front surface. Visible. At this time, it is as described above that TIME and ALARM are conspicuous with relatively high luminance and are difficult to see because they are thin lines.

  As described above, in the electronic timepiece 1, the light-transmitting pattern 42 and the like are further formed on the reflector (layer) 40. Etc. are illuminated in the form of thin lines with high brightness and avoiding glare, so that the variety of display by the liquid crystal display panel 10 can be realized by directly utilizing the characteristics of the light source 50 itself. As a result, the light source 50 works as a surface light source in cooperation with the light guide plate 30 in a region other than the region D35 in front of the recess 35 in the display region D of the liquid crystal display panel 10, while the region D35 in front of the recess 35. Then, it works to give a high-intensity display that is partially conspicuous, and can work in two ways as a whole. Moreover, the arrangement of the light source 50 makes it possible to minimize the sizes of the liquid crystal display device 1 and the wristwatch 2.

  That is, in this liquid crystal display device 1, as can be seen from FIGS. 1A and 1B, the case 4 has the liquid crystal display panel because there is no portion constituting the backlight 20 outside the liquid crystal display panel 10. 10 is sufficient, and the planar size of the liquid crystal display device 1 and the wristwatch 2 including the same can be minimized.

  Note that the background area D35 has a low level as shown by an imaginary line S3 or a broken line S4 in FIG. 2B instead of the lowest level (dark part) as shown by the line S2 in FIG. A translucent part may be sufficient. Such a low light transmission part 40 can be realized by, for example, a diffuse transmission layer or a color filter layer instead of the reflection layer.

  In some cases, the polarizing plate portion corresponding to the region D35 of the polarizing plate 14 is arranged so that the region D35 of the liquid crystal display panel 10 is a negative display that is inverted from the other regions of the display region D. The polarizing plate is oriented in a direction different by 90 degrees from the other regions, and in each of the regions D41a, D41b or D42a, D42b, D42c, D42d of the display region D41 or D42, the translucent pattern 41a, 41b or 42a, 42b, 42c. , 42d itself may be controlled so that the display control unit 17 is controlled. In that case, the low light transmission part 40 consists of the corresponding regions D41 and D42 of the liquid crystal display panel 10 itself. At this time, the bottom surface of the recess 35 is typically translucent, but if desired, a desired level of diffusive transmission plate (layer) may be used to avoid passing excessive intensity light through the negative display area. ) Or a color filter plate (layer).

  Further, in some cases, the low light-transmitting portion 40 itself is not provided with the light-transmitting patterns 41 and 42, for example, simply on the back side (front side) of the reflecting surface facing the light source side, A character may be described and visible from the front side.

  In addition, LED50 may exist in the center part of the display area D instead of being located in the vicinity of the corner part of the display area D like said example. Further, instead of having one LED 50, a plurality of LEDs 50 may be arranged at a plurality of locations in the display area D. Further, the display area D may have another shape such as a circle or an ellipse instead of a rectangle as in the above example.

1 shows a timepiece having a liquid crystal display device according to a preferred embodiment of the present invention, in which (a) is a cross-sectional explanatory view of a part of the timepiece, and (b) is within the range of the liquid crystal display panel of the timepiece of (a) FIG. 1 shows the light intensity of the liquid crystal display device of the watch of FIG. 1, wherein (a) is an explanatory plan view showing the state of light propagation and intensity change in the same range as (b) of FIG. 2, (b). FIG. 6A is a graph schematically showing distance dependency of the intensity of light from a light source along the section taken along line IIB-IIB in FIG. FIG. 2 is a diagram illustrating a low light-transmitting portion of the liquid crystal display device of the watch of FIG. 1, in which (a) is an explanatory plan view illustrating an example in which two types of light-transmitting patterns are formed on a reflective layer; An explanatory plan view showing the state of the display area corresponding to (a) in the liquid crystal display panel, (c) an explanatory plan view showing an example in which four types of translucent patterns are formed on the reflective layer, (d) ) Is an explanatory plan view showing the state of the display area corresponding to (c) of the liquid crystal display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Electronic timepiece in the form of a wristwatch 3 Case 5 Glass 7 Main substrate 10 Liquid crystal display panels 13 and 14 Polarizing plate 16 Display control unit 17 High brightness area display control unit 20 Backlight 30 Light guide plate 31 Main surface)
32 Reflective light guide layer 33 Front surface (first main surface)
35 Concave portion 36 Bottom surface 37 Peripheral surface 40 Low light-transmitting portions 41, 41a, 41b Light-transmitting patterns 42, 42a, 42b, 42c, 42d Light-transmitting patterns 50 LED (light source)
B Light intensity D Display areas D41, D41a, D41b, D42, D42a, D42b, D42c, D42d Display areas E1, E2, E3, E4, E5 Arcs P, S1, S2, S3, S4 Intensity distribution R, R1, R2 , R3, R4, R5 Radius r Distance from LED center

Claims (12)

A liquid crystal display device comprising a transmissive liquid crystal display panel and its backlight,
A light guide plate having a first main surface facing the liquid crystal display panel and a second main surface opposite to the first main surface;
A light source disposed on the second main surface side of the light guide plate within the display area of the liquid crystal display panel;
A liquid crystal display device in which at least one of a liquid crystal display panel and a backlight is located within a display area of the liquid crystal display panel and has a low light-transmitting portion in a high intensity area where the intensity of light from a light source is strong.   The light guide plate includes a recess in the range of the display area of the liquid crystal display panel in the second main surface, the low light-transmitting portion is formed on the bottom surface of the recess, and the light source is disposed in the recess. The liquid crystal display device according to claim 1.   3. The liquid crystal display device according to claim 2, wherein the low light-transmitting portion includes at least one layer selected from the group consisting of a reflective layer, a diffuse transmission layer, and a color filter layer.   The liquid crystal display device according to claim 2, wherein the low light-transmitting portion includes a light-transmitting pattern.   The liquid crystal display device according to claim 4, wherein the low light-transmitting portion includes a plurality of light-transmitting patterns.   The liquid crystal display device according to claim 5, wherein the translucency of a portion of the liquid crystal display panel that faces each of the plurality of translucent patterns is individually controlled.   The liquid crystal display device according to claim 6, wherein the liquid crystal display device is configured to be controlled so that a portion facing at least one of the plurality of translucent patterns is displayed in color.   The liquid crystal display device according to claim 1, wherein the liquid crystal display panel has a low light-transmitting portion in a high intensity region of light from the light source.   The liquid crystal display device according to claim 8, wherein the liquid crystal display device is configured to be controlled so that a low light-transmissive portion of the liquid crystal display panel is negatively displayed.   The liquid crystal display device according to claim 1, wherein the light source is a light emitting diode.   The portable electronic device provided with the liquid crystal display device as described in any one of Claim 1-10.   The portable electronic device according to claim 11, which has a clock function.

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