JP2003015624A - On-screen display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-screen display device capable of realizing to rewrite, move specific information on a still picture, and switch it between displaying and non-displaying thereof speedily and with low power consumption, and also capable of displaying the specific information on the still picture at the same time. SOLUTION: The on-screen display device comprises display data memory 2 (12) for storing only background picture data, and display data memory 2 (13) for storing a composited picture data having composited the on-screen data, and it is possible to switch between displaying and non-displaying of the on-screen data on a display device 206 by selecting them by a selector 16. Moreover, when the displayed contents/position are altered, the background picture data are transferred from the display data memory 1 (12) to update the contents of the display data memory 2 (13). The background data can be stored and the picture data composited with the on-screen data can be stored without necessity for re-converting original picture data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen display device for displaying specific information on a still image at the same time, and more particularly to switching between display / non-display of the specific information on the still image and OSD. The present invention relates to an on-screen display device which aims to change display contents and display position with high speed and low power consumption.

[0002]

2. Description of the Related Art An OSD function of an on-screen display (hereinafter, abbreviated as OSD in the description of the prior art) device is to display a still image as a background by superimposing a plurality of specific information images. It is a function.
For example, in various display devices having a function of displaying a still image such as a digital still camera, a digital video camera, and a television, when displaying various parameter setting values related to image display such as white balance,
On digital still cameras and digital video cameras, the display image number, shooting date, image title, message, etc. are displayed, and on TV, various specific information expressed by characters and figures such as channels and volumes is displayed. It

FIG. 6 shows, as a first conventional technique, an OSD which has an OSD function mounted on a digital still camera.
The apparatus 100 is shown. The original image data that should be the background image is
It is stored in the background image area 102 on the image memory 101 such as a dynamic random access memory (hereinafter abbreviated as DRAM) by the background image creating means 110.
In the digital still camera, the background image creating means 1
As 10, image data captured by an optical system and an image processing system such as a CCD is stored as original image data. The original image data stored here is expanded in the image memory 1 by compressing and storing the data compressed and stored in the medium by the JPEG method or the like.
This is the data stored in 01. Therefore, in order to display this original image data as a still image on a display device such as a liquid crystal monitor or a home television, it is necessary to perform resolution conversion and color space conversion according to the resolution of the display device. is there. This conversion is performed by the data conversion means 105, and the converted data is stored in the display background image area 104 on the image memory 101.

On the other hand, the OSD data creating means 103 is built-in or externally based on the character string or graphic string selected by a character / graphics selection unit (not shown) and information on the arrangement position of these on the display. OSD data is created by arranging the character / graphic fonts to be set.

At the time of display, the video encoder 108
Timing circuit 1 based on horizontal / vertical sync signal from
In synchronization with the timing signal from 07, the image memory 10
Image data for display from 1 and OSD data creating means 1
The character string / graphic string information created in 03 is the selector 1
It is input to 06. In the selector 106, the OSD which is the character / graphic position information from the OSD data creating means 103.
In response to the timing signal from the timing circuit 107 which has received the data display instruction signal, the data from the OSD data creating means 103 is selected and output to the video encoder 108 for the pixel at the OSD data position. In this way, specific information such as characters and figures is combined with the background image and output to the display device 109.

A second prior art OSD device 20 shown in FIG.
In 0, first, the data in the background image area 201 of the image memory is converted by the data converting means 203.
The converted data is selected by the selector 207 and stored in the display data memory 204. Next, the selector 207 selects the OSD data from the OSD data area 202 and overwrites the address corresponding to the display position on the display data memory 204. In the second conventional technology,
The OSD data creating means 10 in the first conventional technique is used because the composite image data is created by combining the OSD data in advance.
There is no restriction on the display content of OSD data due to the response speed of the circuit as in the case of 3, and the OSD device 200 arranges arbitrary image data at an arbitrary position.

In the above first and second prior arts, the OSD device 10 used in the digital still camera is used.
Although 0 and 200 have been described as an example, since the original image data serving as a background image is moving image data even in a video, a television, etc., when this data is used as a still image data,
It is necessary to perform data conversion processing such as resolution. Therefore, the OSD function for still images such as videos and televisions has the same configuration as the OSD devices 100 and 200.

[0008]

However, in the first prior art, it is difficult to design the timing of the circuit because the timing circuit 107 is required to switch the background image data and the OSD data for each pixel in real time. There is a problem. Further, there is a problem that power consumption cannot be reduced due to a circuit operation accompanying high-speed data switching.

In addition, in the second prior art, the display data memory 2 can be operated only by changing the display contents of the OSD data, moving the display position, and switching the display / non-display of the OSD data.
It is necessary to rewrite all the contents of 04. That is, it is necessary to re-store the background image data and then overwrite the required OSD data on a predetermined display position. In this case, for the background image data, the original image data is read from the background image area 201 of the image memory, and the read original image data is converted by the data conversion means 203, and then the display data memory is used. It needs to be stored again in 204. Each time the display content of OSD data is changed, the display position is moved, and display / non-display is switched, the above processing time is required, which is a problem, and power consumption is generated by the circuit operation for executing the above processing operation. It is a problem. Power consumption is a particular problem for battery-powered portable devices such as digital still cameras, as it causes a pressure on continuous use time.

The present invention has been made to solve the above-mentioned problems of the prior art. In an OSD device that simultaneously displays specific information on a still image, the specific information is rewritten, moved, and displayed on the still image. It is an object of the present invention to provide an OSD device capable of realizing non-display switching at high speed and low power consumption.

[0011]

In order to achieve the above object, an on-screen display device according to claim 1 is an on-screen display device for displaying still image data stored in a display data memory on a display device. , A first display data memory for storing background image data in which specific information is not combined, a second display data memory for storing combined image data in which specific information is combined with background image data, and output from the first display data memory And a transfer unit for appropriately switching between the background image data and the composite image data output from the second display data memory and transferring to the display device.

In the on-screen display device according to claim 1, the background image data is stored in the first display data memory, and the combined image data obtained by combining the background image data with the specific information is stored in the second display data memory. There is.
The background image data output from the first display data memory and the composite image data output from the second display data memory are appropriately switched and output to the display device by the transfer unit.

Thus, the first display data memory that stores only the background image data and the second display data memory that stores the combined image data in which the specific information is combined with the background image data are separately provided. Therefore, when displaying on the display device, the display / non-display of the specific information can be switched only by selecting either the first or second display data memory. There is no need to perform processing such as data conversion from the original image data of the background image to regenerate the background image data every time the display / non-display of the specific information is performed, and the display / non-display can be switched quickly. Moreover, it can be performed with low power consumption.

An on-screen display device according to a second aspect is the on-screen display device according to the first aspect, wherein two or more second display data memories are provided, and different composite images are provided for each second display data memory. Data is stored in advance, and one data is appropriately selected from the background image data output from the first display data memory and the two or more combined image data output for each second display data memory. And a transfer means for transferring to the display device.

According to another aspect of the on-screen display device of the present invention, the two or more composite image data are two or more second image data.
It is stored in the display data memory, and by the transfer means,
Any one of the two or more combined image data and the background image data stored in the first display data memory is output to the display device.

With this configuration, since it is possible to individually provide the composite image data combined with the background image data for each specific information, it is possible to switch the display / non-display of the specific information and to change the display content of the specific information. Any one of the first display data memory or each second display data memory 1
Switching can be performed by selecting only one. It is not necessary to perform processing such as switching between display / non-display of specific information and changing display content each time the original image data of the background image is converted to regenerate the background image data. Can be switched quickly and with low power consumption.

An on-screen display device according to a third aspect is the on-screen display device according to the first or second aspect, wherein the background image data output from the first display data memory is stored in the second display data memory. The input data is

Thus, when the contents of the second display data memory are rewritten to change the display contents of the specific information or the display position, the background image data is transferred from the first display data memory to the second display data memory. can do.
Therefore, it is not necessary to perform data conversion from the original image data of the background image to regenerate the background image data each time the display content of the specific information is changed or the display position is changed, and the display content / display position can be changed quickly. And low power consumption.

The first display data memory and the second display data memory are preferably synchronous semiconductor memory devices. As a result, if the operating conditions of the first and second display data memories are matched, the background image data can be efficiently transferred, which greatly contributes to the high-speed processing of changing the display content / display position. is there.

The on-screen display device according to a fourth aspect is an on-screen display device for displaying still image data stored in the display data memory on the display device, wherein the display data memory is combined with specific information. A first display data area for storing non-existing background image data, a second display data area for storing combined image data in which specific information is combined with the background image data, and background image data output from the first display data area, The present invention is characterized by further comprising a transfer unit for appropriately switching the composite image data output from the second display data area and transferring the composite image data to the display device.

In the on-screen display device according to the fourth aspect, in the display data memory, the background image data is stored in the first display data area, and the combined image data obtained by combining the specific information with the background image data is displayed in the second display. It is stored in the data area. The background image data output from the first display data area and the composite image data output from the second display data area are appropriately switched and output to the display device by the transfer unit.

As a result, the display data memory is divided into two areas, the first display data area and the second display data area, and only the background image data is stored in the first display data area. Since the composite image data in which the specific information is combined with the background image data is stored in the area, it is necessary to select one of the first and second display data areas when displaying on the display device. It is possible to switch the display / non-display of the specific information only by. The selection at this time can be easily performed by switching the highest address in the display data memory. When displaying or hiding specific information, it is not necessary to convert the original image data of the background image to regenerate the background image data, and to switch between display and non-display quickly.
Moreover, it can be performed with low power consumption.

An on-screen display device according to a fifth aspect is the on-screen display device according to the fourth aspect, wherein two or more second display data areas are provided, and a different composite image is provided for each second display data area. Data is stored in advance, and background image data output from the first display data area and 2 output for each second display data area
It is characterized by further comprising: a transfer unit for appropriately selecting one of the one or more combined image data and transferring the selected data to the display device.

In the on-screen display device according to the fifth aspect, the two or more composite image data are stored in the two or more second display data areas, and the transfer means stores the two or more composite image data. , One of the background image data stored in the first display data area
Data is output to the display device.

As a result, the composite image data, which is composited with the background image data for each specific information, is stored in the second display data memory.
Since the display data area can be provided for each display data area, it is possible to switch the display / non-display of the specific information and also to change the display content of the specific information in the first display data area or each of the second display data areas.
The switching can be performed only by selecting any one of the display data areas. It is not necessary to perform processing such as switching between display / non-display of specific information and changing display content each time the original image data of the background image is converted to regenerate the background image data. Can be switched quickly and with low power consumption.

It is preferable that the background image data output from the first display data area is used as input data to the second display data area. Thereby, the background image data is stored in the second display data area by transferring the data from the first display data area to the second display data area after selecting the first display data area and storing the background image data. can do. If the data stored in the first display data area is background image data obtained by data conversion from the original image data of the background image, this data conversion processing is necessary to store the background image data in the second display data area. Therefore, the processing speed can be increased or the power consumption can be reduced, which is convenient.

When rewriting the contents of the display data memory to change the display contents of the specific information or the display position, the background image data is transferred from the first display data area to the second display data area. Therefore, it is not necessary to perform data conversion from the original image data of the background image to regenerate the background image data, and the display content / display position can be changed quickly and with low power consumption.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The on-screen display of the present invention (hereinafter, in the description of the embodiments of the invention,
First and second embodiments embodying an apparatus (abbreviated as OSD) will be described in detail based on FIGS. 1 to 5 with reference to the drawings. FIG. 1 is a functional block diagram showing the on-screen display device of the first embodiment. Figure 2
FIG. 3 is a circuit block diagram showing the on-screen display device of the first embodiment. FIG. 3 is an example of an operation timing chart when the display data memory is configured by the SDRAM in the first embodiment. FIG. 4 is a functional block diagram showing the on-screen display device of the second embodiment. FIG. 5 is a circuit block diagram showing the on-screen display device of the second embodiment. Figure 6
It is a functional block diagram which shows the on-screen display apparatus of 1st prior art. FIG. 7 is a functional block diagram showing an on-screen display device of the second related art.

In the functional block 1 of the OSD device of the first embodiment shown in FIG. 1, instead of the display data memory 204 in the OSD device 200 of the second prior art shown in FIG. 7, display data for storing only background image data is displayed. Memory 1 (1
2) and two display data memories 1, 2 (12, 13) for storing combined image data in which OSD data is combined with background image data. The display image data from the display data memories 1, 2 (12, 13) is input to the selector 16, and the selector 16 is controlled by the OSD data display / non-display switching signal. Further, in place of the selector 207 of the second conventional technique, two selectors of a selector 1 (14) and a selector 2 (15) are provided. Selector 1 (14)
The converted background image data is input and is controlled by the memory selection signal to display data memory 1 (12).
Alternatively, one of the selectors 2 (15) is selected and the background image data is output. The background image data from the selector 1 (14) and the OSD data from the OSD data area 202 are input to the selector 2 (15), which is selected and displayed by being controlled by the background data / OSD data selection signal. It is output to the data memory 2 (13). Other configurations are the same as those of the OSD device 200 of the second related art. The same components are given the same numbers and their explanations are omitted here.

In the functional block diagram 1 of the OSD device of the first embodiment, two display data memories 1, 2 (12, 1) are shown.
3), and only the background image data and the combined image data in which the OSD data is combined with the background image data are individually stored. Then, by selecting these display data memories 1, 2 (12, 13) with the selector 16, the display of the OSD data on the display device 206 is performed.
The display is switched. Display data memory 1, 2 (1
The storage of the data in 2, 13) is controlled by the selector 1 (14) and the selector 2 (15). First, the display data memories 1 and 2 (12, 1) are selected by the memory selection signal.
3) are both selected to enter the data write state, the selector 1 (14) is controlled, and the background image data converted by the data conversion unit 203 is transferred to the display data memories 1, 2 (12, 13). Stored (data path: A). As a result, the display data memory 1 (1
In 2), only the background image data that is accessed when the OSD data is hidden is stored. Also, the display data memory 2 (13) stores background image data which is a base on which OSD data is combined. After the storage of the background image data is completed, only the display data memory 2 (13) is selected by the memory selection signal to enter the data writing state, and the selector 1 (14) is deactivated to block the transfer of the background image data. It Furthermore, background data / O
The OSD data from the OSD data area 202 is selected in the selector 2 (15) by the SD data selection signal, transferred to the corresponding address in the display memory 2 (13), and the OSD data is stored in the previously stored background image data. Is synthesized.

Further, when the display contents of the OSD data are changed or the display position is moved, the contents of the display data memory 2 (13) need to be updated. Therefore, the background image data that is the background of the OSD data is stored again. At this time, if the background image data already stored in the display data memory 1 (12) is transferred to the display data memory 2 (13) (data path: B), the original image data is converted into the data conversion means 203. Thus, the background image data can be stored in the display data memory 2 (13) without the need for re-data conversion. After this, the OSD data is transferred from the OSD data area 202, and the composite image data in which the background image data and the OSD data whose display content or display position has been changed are combined is displayed data memory 2 (1
It will be stored in 3).

FIG. 2 is a functional block diagram of the OSD device.
FIG. 10 is a circuit block diagram in the case where is embodied in a circuit block.
Is shown. A data bus is provided, the display data memories 1 and 2 (12, 13), the OSD data area 202,
Data transfer between the data conversion unit 203 and the video encoder 205 is performed via a data bus. Further, a display data memory control unit 11 for controlling the display data memories 1, 2 (12, 13) is provided.

The control signals C1 to C6 are input to the display data memory control unit 11. The control signal C3 and the control signal C4 are input to the AND gates 21 and 22, and the control signal C4 of the AND gate 21 is input as a signal of negative logic. The control signal C2 is input to the NOR gate 23 together with the output signal of the AND gate 21. Further, the control signal C5 and the control signal C6 are input to the NOR gate 24 together with the output signal of the AND gate 22. Further, the control signal C1 is input to the AND gate 25 together with the output signal of the NOR gate 23 as a signal of negative logic, and the output signal of the NOR gate 24 and the AND gate 26.
Has been entered in. The output signals XCS1 and XCS2 of the AND gates 25 and 26 are displayed data memory 1 (1
2) 2 (13) chip select terminals XCS1 and XCS2
Has been entered in. Then, the display image data is output from the data conversion unit 203 and converted into the background image data, and is output from the OSD data area 202.
SD data and the SD data are input to the selector 27, and the data output from the selector 27 is connected to the data bus.

In the circuit block 10 of FIG. 2, the image data transferred via the display data memory 1 (12) and the display data memory 2 (13) is transferred to the functional block represented by the functional block 1 of FIG. After configuring the bus as the center, selector 1 (14), selector 2 (15),
And the selector 16 is embodied as the display data memory control unit 11.

Various controls in the display data memory controller 11 will be described below based on the input control signals C1 to C6. The control signal C1 is a memory 1 / memory 2 simultaneous selection signal. A display data memory 1 (12) that stores only background image data and a display data memory 2 (1) that stores combined image data in which OSD data is combined
This is a selection signal when both 3) and 3) are selected at the same time. When a high level signal is input, AND gates 25 and 2
The output signals XCS1 and XCS2 of 6 become low level regardless of the signal levels of other input signals. This signal is input to the chip selection terminals XCS1 and XCS2 of the display data memories 1 (12) and 2 (13), but since these terminals are low active terminals, the display data memories 1 (1
2) and 2 (13) will be selected together. In this selected state, if the background image data from the data conversion means 203 is selected by the background data / OSD data selection signal which is a control signal to the selector 27, the background image data is transferred to the data bus. By inputting a write instruction signal to both memories 1 and 2 (12, 13), the same background image data can be written at the same time. The data transfer path in this case is shown in FIG.
Indicated as A in the figure.

After the background image data is stored in both memories, the OSD data is combined with the display data memory 2 (13). In this case, only the display data memory 2 (13) is set to the writing state, and the display data memory 1 (1
Writing to 2) must be prohibited. Therefore, while the control signal C1 is transited to the low level, the control signal C2
The OSD data write instruction signal, which is the control signal C5, transits to the high level while maintaining the low levels of C4 to C6. As a result, the output signal of the NOR gate 24 is inverted to the low level, and the output signal XCS2 of the AND gate 26 is inverted to the low level. On the other hand, the control signal C3
Is low level, the input signal of the AND gate 21 maintains low level, and the output signal of the NOR gate 23 is high level when the control signal C2 is low level. Since the control signal C1 is at low level, the output signal XCS1 of the AND gate 25 maintains high level. Therefore, the display data memory 1 (1
2) is the display data memory 2 with no chip selected.
Only (13) will be chip-selected. At this time, the background data / OS which is a control signal to the selector 27
If the OSD data from the OSD data area 202 is selected by the D data selection signal, the OS is placed on the data bus.
Since the D data is transferred, the OSD data can be overwritten on the already written background image data by inputting a write instruction signal (not shown) to the display data memory 2 (13). The control signal C5 is changed to a high level only by an unillustrated control circuit for an address on the display data memory 2 (13) corresponding to the display position of the OSD data stored in the OSD data area 202. This allows the OSD data to be overwritten at a predetermined position while leaving the background image data.

By the above operation, the display data memory 1
Only background image data is stored in (12), and combined image data in which OSD data is overwritten on the background image data is stored in the display data memory 2 (13). By appropriately selecting these memories 1, 2 (12, 13), display / non-display of the OSD data in the image data can be switched.

First, the case of displaying OSD data will be described. The image display instruction signal that is the control signal C3 and the OSD data display instruction signal that is the control signal C4 are both set to a high level. In the AND gate 21, the control signal C4
AND gate 2 because it is activated for the negative logic signal of
The output signal of 1 becomes low level, and the other control signals C1 and
Since C2 is at low level, the output signal of the NOR gate 23 becomes high level, and the output signal XCS1 of the AND gate 25 becomes high level. Therefore, the display data memory 1 (12) is not selected. On the other hand, the output signal of the AND gate 22 becomes high level, and the NOR gate 2
The output signal of 4 becomes low level, and the output signal XCS2 of the AND gate 26 becomes low level. Therefore, the display data memory 2 (13) is in the selected state. At this time, the display data memory 2 (1
When 3) is set to the read state, the composite image data obtained by combining the OSD data is read and output to the video encoder 205 via the data bus. Therefore, an image in which the OSD data is overwritten on the background image is output to the display device 206.

Next, a case where the OSD data is hidden will be described. The image display instruction signal which is the control signal C3 is set to the high level, and the OSD which is the control signal C4
Set the data display instruction signal to low level. Since the AND gate 21 is activated with respect to the negative logic signal of the control signal C4, the output signal of the AND gate 21 becomes high level and the output signal of the NOR gate 23 becomes low level. The output signal XCS1 of the AND gate 25 also becomes low level, and the display data memory 1 (12) is in the selected state. On the other hand, the output signal of the AND gate 22 becomes low level. Since the other control signals C5 and C6 are at the low level, the output signal of the NOR gate 24 is at the high level, and the output signal XCS2 of the AND gate 26 is at the high level when the control signal C1 is at the low level. Therefore, the display data memory 2 (13) is not selected. At this time, if the display data memory 1 (12) is set to the read state while the selector 27 is deselected, the background image data is read and output to the video encoder 205 via the data bus. Therefore, only the background image is output to the display device 206.

With the control signal C3 set to the high level,
By controlling the logic level of the control signal C4, the display of the OSD data on the image displayed on the display device 206 is performed.
Hiding can be controlled.

Further, the change of the display contents of the OSD data and the movement of the display position will be described. Display data memory 2
The composite image data in which the OSD data stored in (13) is composited needs to be updated because the display content of the OSD data is changed or the display position is moved. Therefore, it is necessary to store the background image data again and overwrite the predetermined OSD data at a predetermined position.

First, the storage of background image data will be described. Regarding the background image data, since the data which has been subjected to the size conversion and the color conversion in the data conversion means 203 is already stored in the display data memory 1 (12), this background image data is transferred. Control signals C1, C
While maintaining 3 to C5 at low level, control signal C
2, C6 is transited to the high level. NOR gate 23, 2
The output signals of 4 are both low level, and the output signals XCS1 and XCS2 of the AND gates 25 and 26 to which these low level signals are input are both low level. Therefore, the display data memory 1 (12) and the display data memory 2
Both (13) are in the selected state. In this state, the display data memory 1 (12) is set to the reading state and the display data memory 2 (13) is set to the writing state while the selector 27 is not selected. The background image data is read from the display data memory 1 (12) onto the data bus, and this background image data is written to the display data memory 2 (13). In this way, the background image data is transferred to the display data memory 2 (13). The data transfer path in this case is shown as B in FIG.

In the background image data transfer operation described above, the display data memory 1 (12) and the display data memory 2 (13) are synchronized with the synchronous DRAM.
(Hereinafter, abbreviated as SDRAM) is preferable. This is because the display data memory 1 (12) is subjected to the burst read operation while the display data memory 2 (13) is subjected to the burst write operation, whereby the transfer operation of the image data can be continuously performed. FIG. 3 shows a timing chart of the burst operation. Figure 3 shows the SDR
As an AM, a case where the CAS latency is 2 and the burst length is 4 is illustrated. The signal CLK is an operation clock signal of the SDRAM. The signals XCS1 and XCS2 are displayed data memory 1 (12) and display data memory 2 (1
It is a chip selection signal of 3) and is a low active signal. The signal XRAS is a row address selection signal, the signal XCAS is a column address selection signal, the signal XWE is a write enable signal, and both are low active signals. The signal ADRS is an address signal and the signal DATA is a data signal. Signals CLK, XRAS, XCAS, XWE, ADR other than the chip selection signals XCS1 and XCS2
S and DATA are signals common to the display data memory 1 (12) and the display data memory 2 (13).

At the timing of the rising edge of the clock signal CLK, both the chip selection signal XCS1 and the row address selection signal XRAS are set to the low level, so that the display data memory 1 (12) receives the address signal AD.
RS is taken in as a row address. That is, an active command is given to the display data memory 1 (12). In this example, the chip selection signal XCS1 and the column address selection signal XC are generated at the edge after two cycles.
Write enable signal X while AS is low level
WE maintains the high level, and the display data memory 1 (1
Give a read command to 2). Display data memory 1
In (12), since the CAS latency is 2, this 2
The data is output so that the data can be continuously taken in for four cycles specified by the burst length from the edge after the cycle. This is a so-called burst read operation.

Regarding the display data memory 2 (13),
The burst write operation is performed in synchronization with the read operation of the display data memory 1 (12). First, the active command (edge) of the display data memory 1 (12)
At the edge timing that is one cycle delayed from
Chip selection signal XCS2 and row address selection signal XR
Both AS are set to low level and the address signal ADRS is taken in as a row address. That is, an active command is given to the display data memory 2 (13). The subsequent write command is given in accordance with the data read cycle from the display data memory 1 (12). That is, at the edge, both the chip selection signal XCS2 and the column address selection signal XCAS are set to low level,
At the same time, the write enable signal XWE is set to low level, and a write command is given to the display data memory 2 (13). Therefore, the timing of the burst read from the display data memory 1 (12) and the timing of the burst write to the display data memory 2 (13) match, data transfer can be performed directly, and a buffer area or the like is provided in the middle. Need not be set. When the CAS latency is 2 and the burst length is 4, the data transfer is completed in 8 cycles, and then a cycle for precharging of 2 cycles is added to add a 4-bit memory bus width in 10 clock cycles. Data transfer can be completed. still,
The column address may be designated for each memory for each burst length, and the precharge may be postponed. By doing so, efficient transfer can be performed.

After the transfer of the background image data to the display data memory 2 (13) is completed, the OSD data is overwritten. As described above, by controlling the control signal C5 to the high level while maintaining the control signals C1 to C4 and C6 at the low level, the output signal XCS of the AND gate 26 is changed.
The display data memory 2 (13) is selected by setting 2 to the low level. In this state, if the OSD data from the OSD data area 202 is selected by the background data / OSD data selection signal which is a control signal to the selector 27,
Since the OSD data is transferred onto the data bus, the OSD data can be overwritten on the already written background image data by inputting a write instruction signal (not shown) to the display data memory 2 (13). The high level transition of the control signal C5 is caused by the control circuit (not shown) that stores the OSD data stored in the OSD data area 202.
Display data memory 2 (1
3) Do only for the above addresses. This allows the OSD data to be overwritten at a predetermined position while leaving the background image data.

According to the OSD device (function block 1 and circuit block 10) of the first embodiment, the display data memory 2 (13) in which only background image data is stored and the OSD data are combined with the background image data. Since the display data memory 2 (13) storing the combined image data is separately provided, only one of the memories 1, 2 (12, 13) can be selected when displaying on the display device 206. With, the display / non-display of the OSD data can be switched. At this time, by setting the control signal C1 (memory 1 / memory 2 simultaneous selection signal) to a high level, output signals XCS1 and XC output from the AND gates 25 and 26 are output.
Both S2 become low level, and the display data memory 1 (1
2) Since the background image data can be simultaneously stored by selecting both the display data memory 2 (13), the background image data can be efficiently stored in a short time.
When the OSD data is displayed / hidden, it is not necessary to regenerate the video data for display by performing data conversion such as size conversion and color conversion on the background image which is the original image data. It is not necessary to process a large amount of original image data each time the OSD data is displayed / hidden switched, and the display / hidden switching can be performed quickly and with low power consumption.

When the contents of the display data memory 2 (13) are rewritten to change the display contents of the OSD data or move the display position, the display data memory 1 (12) to the display data memory 2 (13) are changed. The background image data can be transferred to, and there is no need to regenerate the video data for display by performing data conversion such as size conversion and color conversion on the background image which is the original image data. It is not necessary to process a large amount of original image data each time the display content of OSD data is changed or the display position is moved, and the content / position can be changed quickly and with low power consumption.

If the display data memory 1 (12) and the display data memory 2 (13) are constructed by a synchronous semiconductor memory device such as SDRAM, and the operating conditions of both memories 1, 2 (12, 13) are made to match. The background image data can be efficiently transferred, which contributes to high-speed processing of changing contents / positions.

In the functional block 2 of the OSD device of the second embodiment shown in FIG. 4, a display data memory 22 is provided instead of the display data memory 204 of the OSD device 200 of the second prior art shown in FIG. Display data memory 2
Reference numeral 2 denotes a display data storage area, a first area 23 for storing only background image data and a second area 24 for storing combined image data in which OSD data is combined with background image data.
And is divided into two areas. A memory area designation control unit 25 for selecting from which of the two areas 23 and 24 the data is to be read is provided.
B) The address is output. Further, a display data memory control unit 21 is provided instead of the selector 207 of the second conventional technique. The display data memory control unit 21 receives the background image data data-converted by the data conversion unit 203 and the OSD data from the OSD data area 202, and selects and outputs any one of the data. For other configurations, the OSD of the second conventional technique is used.
Similar to device 200. For the same components,
The same numbers are assigned and the description is omitted here.

The circuit block 20 of the OSD device of the second embodiment represents the configuration in the display data memory control unit 21 in the functional block 2 of FIG. 4 as a circuit block, and embodies the configuration with the display data memory 22. It was done. As shown in FIG. 5, the display data memory control unit 21 has a display data memory 2 having two areas 23 and 24.
Equipped with 2. The selection of the areas 23 and 24 for storing data is controlled by the selector 33 in the display data memory control unit 21. That is, the selector 33 is controlled by the switching signal of the area 1 / area 2 of the display data memory, and either the upper address storage unit 31 of the area 1 or the higher address storage unit 32 of the area 2 is selected. , Is output as the upper address of the display data memory 22. As for the lower address, the address generated by the lower address generation unit 34 is output as the lower address of the display data memory 22.

The background image data and the OSD data are sent to the display data memory control unit 21 via the data bus.
Data is transferred between the display data memory 22 and the display data memory 22. In the display data memory control unit 21, a data latch unit 35 used as a buffer when transferring background image data from the first area 23 of the display data memory 22 to the second area 24, and a data conversion unit 203. A selector 36 for selecting the background image data that has been data-converted by the OSD data and the OSD data from the OSD data area 2020;
A path is provided for transferring data from the data bus to the video encoder 205.

OSD device 2 of the second embodiment shown in FIG.
In (and the circuit block 20 in FIG. 5), when storing the data in the display data memory 22, first, it is necessary to store the background image data in the first area 23 and the second area 24. In this case, the display data memory 22 is selected by a chip selection signal (not shown), and while the lower address is generated by the lower address generation unit 34, the upper address is sequentially switched by the selection of the selector 33 to switch the first and second addresses. Areas 23 and 24 are selected.
Specifically, the selector 33 is controlled by the switching signal of the area 1 / area 2 of the display data memory, and the upper address to be supplied to the display data memory 22 is set at the timing when the lower address from the lower address generation unit 34 has completed one cycle. ,
The address from the upper address storage unit 31 of the area 1 that specifies the first area 23 is switched to the address from the upper address storage unit 32 of the area 2 that specifies the second area 24, and the lower address generation unit 34 again. Is performed by outputting the lower address from. The background image data selected by the selector 36 is transferred to the data bus according to each address thus selected. At this time, if a write instruction signal (not shown) is input to the display data memory 22, the same background image data can be sequentially written in the first and second areas 23 and 24. The data transfer path in this case is shown as A in FIG.

After the background image data is stored in the first and second areas 23 and 24, the OSD data is combined in the second area 24. In this case, the lower address is output from the lower address generation unit 34 while the upper address is fixed to the address from the upper address storage unit 32 of the area 2 by the selector 33. At this time, the output of the lower address is
Control is performed by selectively generating an address corresponding to the display position of the OSD data to be combined based on the OSD data from the OSD data area 202 by a control signal (not shown). In accordance with this lower address, the selector 36
Then, the OSD data from the OSD data area 202 is transferred to the data bus. At this time, if a write instruction signal (not shown) is input to the display data memory 22, the OSD data can be overwritten in the second area 24.

By the above operation, the display data memory 22
In the first area 23, only the background image data is stored, and in the second area 24, the composite image data in which the OSD data is overwritten on the background image data is stored. By appropriately selecting these areas 23 and 24 by the memory area designation control unit 25, the display / non-display of the OSD data in the image data can be switched.

When it is desired to display the OSD data, in the chip selection state of the display data memory 22, the highest (MSB) address output from the memory area designation control unit 25 is set to the second area of the display data memory 22. Set to select 24. At this time, if the display data memory 22 is set to the read state while the selector 36 is deselected, the combined image data in which the OSD data is combined is read and output to the video encoder 205 via the data bus. Therefore, the background image is displayed on the display device 206 as O.
The image in which the SD data is overwritten is output.

To hide the OSD data,
In the chip selection state of the display data memory 22, the highest order (MSB) output from the memory area designation control unit 25
The address is set to select the first area 23 of the display data memory 22. At this time, if the display data memory 22 is set to the read state while the selector 36 is deselected, only the background image data is read and output to the video encoder 205 via the data bus. Therefore,
Only the background image is output to the display device 206.

By appropriately switching the highest (MSB) address output from the memory area designation control unit 25, it is possible to control the display / non-display of the OSD data on the image displayed on the display device 206.

In the second embodiment, the case of switching the display / non-display of OSD data on the display device 206 by switching the highest (MSB) address output from the memory area designation control unit 25 will be described. However, the present invention is not limited to this, and it goes without saying that the same data selection is possible by controlling the selector 33 in the display data memory control unit 21 to select the upper address of the display data memory 22. Yes.

When the display content of the OSD data is changed or the display position is moved, the background image data is stored in the second area 24 prior to the transfer of the OSD data, and the first area using the data latch section 35 as the data buffer. This is performed by transferring the background image data from 23. While maintaining the display data memory 22 in the chip selected state, outputting the upper address for selecting the first area 23 by the selector 33,
A predetermined amount of data that can be stored in the data latch unit 35 is read while sequentially changing the lower address. The data latch unit 35 sequentially stores the read data on the data bus. Then, when a predetermined amount of data is stored, the upper address is changed by the selector 33 so as to select the second area 24. Returns the lower address,
While changing again according to the address read from the first area 23, the data latch unit 35 outputs data corresponding to the address. As a result, the second region 24 having the same address as the lower address in the first region 23
Then, the same data is stored and the data is transferred.
The data transfer path in this case is shown as B in FIG.

The first area 23 to the second area shown in FIG.
The transfer of the background image data to the area 24 is not limited to the case where the display content of the OSD data is changed or the arrangement position is moved, and is applicable to the case where the background image data is read from the data conversion unit 203. . That is, in the above description, when the background image data from the data conversion unit 203 is stored in the first and second areas 23 and 24, the upper address is sequentially selected by the selector 33 so that the data conversion unit 203 outputs the background image data. The background image data of 2 is stored in the two areas 23 and 24 twice. In this case, the data is stored twice in the two areas 23 and 24. Therefore, the data conversion means 203
The content of the background image data must be retained until the data storage for each time is completed. Therefore, by setting the data transfer from the first area 23 to the second area 24, the data conversion means 203 can be opened when the data storage in the first area 23 is completed. It is convenient. The data conversion unit 203 can perform the following processing and can perform high-speed processing. Since the circuit operation in the data conversion unit 203 can be suspended without performing the following processing, the power consumption can be reduced.

According to the OSD device 2 (and the circuit block 20 in FIG. 5) of the second embodiment, the display data memory 22 is divided into two areas 23 and 24, and the first area 23 is divided.
The background image data is stored in the second area 24, and the combined image data in which the OSD data is combined with the background image data is stored in the second area 24. The display / non-display of the OSD data can be switched only by selecting 23 or 24. Further, the selection at this time can be easily performed by switching the highest (MSB) address by the memory area designation control unit 25. Display of OSD data
At the time of non-display, it is not necessary to perform data conversion such as size conversion and color conversion on the background image which is the original image data and regenerate the video data for display. It is not necessary to process a large amount of original image data each time the OSD data is displayed / hidden switched, and the display / hidden switching can be performed quickly and with low power consumption.

At this time, the first area 23 is selected and the background image data is stored, and then the data is transferred from the first area 23 to the second area 24.
Also, background image data can be stored. With this setting, the data conversion unit 203 can be opened quickly to move to the next operation or to be in the sleep state, which can expedite the processing or reduce the power consumption, which is convenient. .

When the contents of the display data memory 22 are rewritten to change the display contents of the OSD data or move the display position, the first area 23 to the second area 24 are used.
The background image data can be transferred to, and there is no need to regenerate the video data for display by performing data conversion such as size conversion and color conversion on the background image which is the original image data. It is not necessary to process a large amount of original image data each time the display content of OSD data is changed or the display position is moved, and the content / position can be changed quickly and with low power consumption.

Needless to say, the present invention is not limited to the first and second embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, in the first and second embodiments, in addition to the display data memory that stores only the background image data or the first area in the display data memory, the combined image data in which the OSD data is combined with the background image data is stored. The other display data memory or the second area in the display data memory is set, but the present invention is not limited to this. That is, another display data memory or an area in the display data memory is set, and two or more types of OSs are set.
It is also possible to provide synthetic image data obtained by synthesizing D data, select each image data, and set to switch display of each OSD data or switch display / non-display.

The case where the data selector is set to appropriately switch one of the two data, that is, the background image data and the OSD data, is described as an example. It is also possible to prepare two or more types of background images and two or more types of OSD data and set the switching of the selector so that these combinations can be freely selected.

(Supplementary Note 1) In an on-screen display device for displaying still image data stored in a display data memory on a display device, a first display data memory for storing background image data in which specific information is not combined, A second display data memory that stores combined image data in which specific information is combined with the background image data, background image data output from the first display data memory, and a combined image output from the second display data memory An on-screen display device, comprising: a transfer unit that switches between data and data and transfers the data to the display device. (Supplementary Note 2) Two or more second display data memories are provided, different composite image data is stored for each second display data memory, and background image data output from the first display data memory, The transfer means for appropriately selecting one data from the two or more composite image data output for each of the second display data memories and transferring the selected data to the display device. On-screen display device. (Supplementary Note 3) The on-screen display device according to Supplementary Note 1 or 2, wherein the background image data output from the first display data memory is used as input data to the second display data memory. (Supplementary Note 4) The first display data memory, and the second display data memory.
The on-screen display device according to attachment 3, wherein the display data memory is a synchronous semiconductor memory device. (Supplementary Note 5) In an on-screen display device that displays still image data stored in a display data memory on a display device, the display data memory stores first display data that stores background image data in which specific information is not combined. An area, a second display data area for storing combined image data in which specific information is combined with the background image data, and background image data output from the first display data area,
An on-screen display device, comprising: transfer means for appropriately switching the composite image data output from the second display data area and transferring the composite image data to the display device. (Supplementary Note 6) Two or more second display data areas are provided,
Different composite image data is stored for each of the second display data areas, and background image data output from the first display data area and two or more composite images output for each of the second display data areas. The on-screen display device according to appendix 5, further comprising: a transfer unit that appropriately selects one of the image data and transfers it to the display device. (Supplementary note 7) The on-screen display device according to supplementary note 5 or 6, wherein the background image data output from the first display data area is used as input data to the second display data area.

[0068]

According to the present invention, in an on-screen display device that simultaneously displays specific information on a still image, rewriting, moving, and switching between display / non-display of the specific information on the still image can be performed at high speed. It is possible to provide an on-screen display device that can be realized with power consumption.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an on-screen display device according to a first embodiment.

FIG. 2 is a circuit block diagram showing the on-screen display device of the first embodiment.

FIG. 3 shows a display data memory S in the first embodiment.
It is an example of an operation timing chart when it is configured by a DRAM.

FIG. 4 is a functional block diagram showing an on-screen display device according to a second embodiment.

FIG. 5 is a circuit block diagram showing an on-screen display device according to a second embodiment.

FIG. 6 is a functional block diagram showing an on-screen display device of a first conventional technique.

FIG. 7 is a functional block diagram showing an on-screen display device of a second related art.

[Explanation of symbols]

1, 2, 100, 200 Functional block diagram of on-screen display device 10, 20 Circuit block diagram of on-screen display device 11, 21 Display data memory control unit 12 Display data memory 1 13 Display data memory 2 14, 15, 16, 27, 33, 36, 106 selector 22, 204 display data memory 23 first area of display data memory 24 second area of display data memory 25 memory area designation control section 31 upper address designation section 32 of area 1 of area 2 Upper address designator 34 Lower address generator 35 Data latch

Continued front page    F-term (reference) 5C023 AA18 AA21 AA31 AA38 BA11                       BA15 CA01 CA05 CA08 DA04                 5C025 AA30 BA21 BA27 BA28 BA30                       CA03 CA09 CA20 DA08 DA10                 5C082 AA27 BA02 BA12 BB25 CA56                       CB05 DA61 MM04 MM10

Claims (5)

[Claims] 1. An on-screen display device for displaying still image data stored in a display data memory on a display device, a first display data memory for storing background image data in which specific information is not combined, and the background. Second display data memory for storing combined image data in which specific information is combined with image data, background image data output from the first display data memory, and combined image data output from the second display data memory An on-screen display device, comprising: 2. A plurality of second display data memories are provided, different composite image data are stored for each second display data memory, and background image data output from the first display data memory is stored. And a transfer unit that appropriately selects one data from the two or more composite image data output for each of the second display data memories and transfers the selected data to the display device. An on-screen display device according to. 3. The on-screen display device according to claim 1, wherein the background image data output from the first display data memory is used as input data to the second display data memory. . 4. An on-screen display device for displaying still image data stored on a display data memory on a display device, wherein the display data memory stores a first display for storing background image data in which specific information is not combined. A data area, a second display data area for storing combined image data in which specific information is combined with the background image data, background image data output from the first display data area, and output from the second display data area An on-screen display device, comprising: transfer means for appropriately switching the synthesized image data to be transferred to the display device. 5. The second display data area is provided in two or more, different synthetic image data is stored for each second display data area, and background image data output from the first display data area is stored. 5. A transfer means for appropriately selecting one data from the two or more combined image data output for each of the second display data areas and transferring the selected data to the display device. An on-screen display device according to.