IMAGE OUTPUT APPARATUS, METHOD AND PROGRAM THEREOF, AND IMAGING APPARATUS

Abstract

An image output apparatus in which an image output synchronization signal generation circuit conventionally shared for both video (TV) use and liquid-crystal display (LCD) use is divided into two image output synchronization signal generation circuits. The two image output synchronization signal generation circuits are synchronized, and the image format can be changed without taking the current image format into consideration. Thereby, high-definition image formats and liquid-crystal display progressive scanning are supported. Also, a dedicated synchronization counter, which does not have a horizontal counter or a vertical counter, is provided separately from a vertical counter and horizontal counter of a TV image output synchronization signal generation circuit and a horizontal counter and vertical counter of an LCD image output synchronization signal generation circuit. The dedicated synchronization counter is used to manage the operation cycle of the overall system and to perform synchronization and phase adjustment of the TV image output and LCD image output by adjusting the timing for outputting a control signal to the vertical and horizontal counters of the TV image output synchronization signal generation circuit and LCD image output synchronization signal generation circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings that illustrate a specific embodiment of the invention. In the Drawings:

FIG. 1 is a block diagram showing an overall configuration of parts of a digital still camera according to conventional art.

FIG. 2 is a chart showing a list of vertical counter numbers and horizontal counter numbers for each image format.

FIG. 3 is chart showing an overall timing in the case where an image output synchronization signal generation circuit is simply divided in two.

FIG. 4 is a diagram showing an example of a combination of NTSC/PAL image formats for TV image output and LCD image output.

FIG. 5 is a diagram showing various combinations of image formats for TV image output and LCD image output.

FIG. 6 is a block diagram showing an overall configuration of parts of a digital still camera according to the present invention.

FIG. 7 is a block diagram showing a configuration of a dedicated synchronization counter according to the present invention.

FIG. 8 is a flowchart showing an operation of a dedicated synchronization counter according to the present invention.

FIG. 9 is a chart showing a list of operation cycles and operation cycle counter values.

FIG. 10 is a block diagram showing a configuration of an image output synchronization signal generation circuit.

FIG. 11 is a flowchart showing an operation of an image output synchronization signal generation circuit.

FIG. 12 is a chart showing detailed timings during normal operation of the dedicated synchronization counter of the present invention.

FIG. 13 is a chart showing detailed timings during image format switching operation performed by the dedicated synchronization counter of the present invention.

FIG. 14 is a chart showing detailed timings during synchronization and phase adjustment performed by the dedicated synchronization counter of the present invention.

FIG. 15 is a chart showing an overall timing of the dedicated synchronization counter of the present invention.

FIG. 16 is a diagram showing an example where a digital still camera that includes the image output apparatus of the present invention is connected to a TV and the image output signal is changed.

Claims

1. An image output apparatus which outputs an image signal to plural display devices, said apparatus comprising: plural image signal output units, each of which is operable to output an image signal corresponding to at least one image format; anda synchronization unit operable to synchronize the plural image signals outputted from said plural image signal output units.

2. The image output apparatus according to claim 1, wherein said synchronization unit includes a synchronization counter which can count to a maximum value set in accordance with the cycle of an image format, andsaid synchronization unit is operable to synchronize the plural image signals based on the count value of the synchronization counter.

3. The image output apparatus according to claim 2, wherein each of said plural image signal output units includes an image output synchronization signal generation unit having a vertical counter and a horizontal counter, both of which can count to the set maximum value, andsaid synchronization unit is operable to synchronize the count value of said synchronization counter with the vertical counter and horizontal counter included in said plural image output synchronization signal generation units.

4. The image output apparatus according to claim 3, wherein said synchronization unit is operable to adjust the phase of the outputted image signal when the count value of said synchronization counter is a predetermined value so that the vertical counter and horizontal counter are reset.

5. The image output apparatus according to claim 3, further comprising a CPU which can perform a predetermined processing in accordance with a CPU interrupt,wherein said CPU signals a CPU interrupt when said synchronization counter reaches a predetermined value, andsaid synchronization unit is operable to set the vertical counter and horizontal counter due to the CPU interrupt.

6. The image output apparatus according to claim 3, further comprising an image signal input unit which is inputted with an image signal and which includes an image input synchronization signal generation unit having an input signal vertical counter and an input signal horizontal counter, both of which can count to the set maximum value,wherein said synchronization unit is operable to synchronize the synchronization counter, the vertical counters and horizontal counters included in the plural image output synchronization signal generation unit, and the input signal vertical counter and input signal horizontal counter included in the image input synchronization signal generation unit.

7. The image output apparatus according to claim 6, wherein said synchronization unit is operable to adjust the phase of the inputted image signal when the count value of said synchronization counter is a predetermined value so that the input signal vertical counter and input signal horizontal counter are reset.

8. The image output apparatus according to claim 3, further comprising a CPU which can perform a predetermined processing in accordance with a CPU interrupt,wherein said CPU signals a CPU interrupt when said synchronization counter reaches a predetermined value, andsaid synchronization unit is operable to set the input signal vertical counter and input signal horizontal counter due to the CPU interrupt.

9. An imaging apparatus comprising the image output apparatus according to claim 1.

10. An image output method for use in an image output apparatus that can output an image signal to plural display devices, wherein the image output apparatus outputs an image signal to plural display devices, and includes:plural image signal output units, each of which outputs an image signal corresponding to at least one image format; anda synchronization unit which synchronizes the plural image signals outputted from said plural image signal output units, andsaid method comprises:outputting, via each image signal output unit, the image signal corresponding to at least one image format; andsynchronizing the plural image signals outputted from said plural image signal output units.

11. The image output method according to claim 10, wherein in said synchronizing, the plural image signals are synchronized based on the count value of a synchronization counter which can count to a maximum value set in accordance with the cycle of an image format.

12. The image output method according to claim 11, wherein in each instance of said outputting, an image output synchronization signal generation unit, in which a vertical counter and a horizontal counter can count to a set maximum value, is used, andin said synchronizing, the count value of the synchronization counter is synchronized with the vertical counter and horizontal counter included in the image output synchronization signal generation unit.

13. A program for use in an image output apparatus that can output an image signal to plural display devices, wherein the image output apparatus outputs an image signal to plural display devices, and includes:plural image signal output units, each of which outputs an image signal corresponding to at least one image format; anda synchronization unit which synchronizes the plural image signals outputted from said plural image signal output units, andsaid program comprises:outputting, via each image signal output unit, the image signal corresponding to at least one image format; andsynchronizing the plural image signals outputted from said plural image signal output units.

14. The program according to claim 13, wherein in said synchronizing, the plural image signals are synchronized based on the count value of a synchronization counter which can count to a maximum value set in accordance with the cycle of an image format.

15. The program according to claim 14, wherein in each instance of said outputting, an image output synchronization signal generation unit, in which a vertical counter and a horizontal counter can count to a set maximum value, is used, andin said synchronizing, the count value of the synchronization counter is synchronized with the vertical counter and horizontal counter included in the image output synchronization signal generation unit.